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5631 articles

B3019 – Etude thermodynamique de la sorption de l’uranyle sur la monazite et la magnétite

mon travail concerne l’étude des phénomènes de sorption intervenant entre un ion radiotoxique « modèle » en solution aqueuse, l’ion uranyle UO2 2+ et deux substrats minéraux : la monazite, composé méthodologique, système relativement simple sur lequel une étude structurale à température ambiante a déjà été réalisée et la magnétite, dépôt poreux issu de la corrosion des composants en acier au carbone du poste d'eau du circuit secondaire des REP et produit de corrosion des containers métalliques destinés au stockage des déchets radioactifs en formation géologique profonde
Olivia Felix, Thèse Institut de Physique Nucléaire d'Orsay, Juillet 2012

B3018 – Direct measurement of the heat of solution and solubility of carbon dioxide in 1-hexyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide and 1-octyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide

We report the first direct experimental determination of the enthalpies of solution of carbon dioxide in ionic liquids 1-hexyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide ([C6mim][NTf2]) and 1-octyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide ([C8mim][NTf2]) at 313.15 K and pressures up to 5 MPa. The experiments are based on the detection of heat of mixing of gas with ionic liquid using a flow calorimetric technique. For both ionic liquids, gas solubilities were derived from experimental calorimetric data and were compared with solubility data obtained by a newly designed high-pressure solubility measurement apparatus. Results of enthalpies of solution were compared to enthalpies derived from Henry’s law constant, available in literature. The analysis of the data reported herein confirms the consistency between the direct determination of the heats of solution and their derivation from precise enough solubility data. Also it was proven that, within the experimental uncertainty, it is possible to derive reliable solubility data from the calorimetric experiments.
D. Almantariotis, O. Fandino, J.-Y. Coxam, M.F. Costa Gomes, International Journal of Greenhouse Gas Control 10 (2012) 329–340

B3017 – The effect of surface acidic and basic properties on the hydrogenation of lauronitrile over the supported nickel catalysts

Supported nickel catalysts with different supports (MgO, SiO2, Al2O3, MgAlO and SiAlO) were prepared by the co-precipitation method and dried in n-butanol. Nickel was found to be relatively easier to reduce in Ni/MgO and Ni/SiO2 than in Ni/Al2O3, while nickel was higher dispersed in Ni/SiO2 than in Ni/Al2O3 and Ni/MgO. Thus, the reducibility and dispersion of nickel in Ni/MgAlO and Ni/SiAlO were significantly enhanced, leading to the high active nickel surface areas (75 m2/g-catalyst). Acetonitrile was found to be adsorbed on the reduced nickel and acidic sites. The strong surface basicity of Ni/MgO was found to favor the selectivity to the primary amine, but inhibited the conversion of lauronitrile. On the other hand, the conversion of lauronitrile was high over the Ni/SiO2, Ni/Al2O3 and Ni/SiAlO with strong surface acidity, but the selectivity to the prime amine was relatively low. The Ni/MgAlO with intermediate strengths of surface acidity and basicity exhibited the high conversion of lauronitrile and high selectivity to the prime amine.
Hui Chen, Mingwei Xue, Shenghua Hu, Jianyi Shen, Chemical Engineering Journal 181– 182 (2012) 677– 684

B3016 – The effects of promoters of K and Zr on the mesoporous carbon supported cobalt catalysts for Fischer–Tropsch synthesis

The mesoporous carbon supported cobalt catalyst (15%Co/MC) was found to be more active and selective to C+5 than the traditionally activated carbon supported one (15%Co/AC) for the Fischer–Tropsch synthesis (FTS). The addition of small amount of K2O and ZrO2 significantly affected the FTS behavior of 15%Co/MC. The addition of 1% K inhibited the FTS activity dramatically, while the addition of 3% Zr increased the FTS activity significantly. The addition of K2O decreased the surface acidity while increased the surface basicity of 15%Co/MC, resulting in the increased heat of adsorption of CO and substantially decreased heat of adsorption of H2 on Co. In contrast, the addition of ZrO2 increased the surface acidity and heat of adsorption of H2 on Co. The FTS activity was found to be related to the ratio of heats for the adsorption of CO and H2 on the catalysts 15%Co/MC, 15%Co–1%K/MC and 15%Co–3%Zr/MC. The highest FTS activity was obtained on the catalyst with the heat ratio of 1.2.
Liang Chen, Guoxia Song, Yuchuan Fu, Jianyi Shen, Journal of Colloid and Interface Science 368 (2012) 456–461

B3024 – Denaturation and aggregation processes in thermal gelation of whey proteins resolved by differential scanning calorimetry

Gelation of globular proteins on heating involves two separate stages. The first is partial unfolding (denaturation) of the native globular structure; the second is intermolecular aggregation. Denaturation involves dissociation of intramolecular bonds (non-covalent and, in some cases, disulfide) and is therefore an endothermic process. The aggregation step involves formation of new bonds between protein molecules, and would therefore be expected to give a differential scanning calorimetry (DSC) exotherm on heating, but numerous previous studies of the thermal gelation of whey proteins, carried out on conventional (fast scanning) DSC calorimeters (typical sample mass 15–50 mg), have shown only endothermic transitions. In the present work, however, we have observed the endothermic (denaturation) and exothermic (aggregation) processes in thermogelation of whey protein isolate (WPI) as separate transitions in DSC heating traces recorded on a Setaram microcalorimeter (sample mass 850 mg). Under conditions where aggregation occurs much more slowly than denaturation (low protein concentration; low ionic strength) the two transitions are well resolved, with the exotherm from aggregation following the endotherm from denaturation. The position of the exotherm, however, appears to be time-dependent rather than temperature-dependent. On reduction in heating rate, the apparent peak-maximum temperature of the aggregation exotherm decreases towards the (essentially constant) position of the denaturation endotherm, and, at sufficiently low scan rates, the exotherm becomes obscured by the more intense endotherm. Progressive displacement of the exotherm into the temperature range of the denaturation endotherm also occurs in response to changes that accelerate intermolecular aggregation and accompanying gelation (addition of salt; increasing protein concentration). The absence of a detectable exotherm in previous studies using conventional calorimeters is attributed to the much smaller sample mass than in the Setaram instrument, giving much faster heat transfer, which may cause the exothermic heat flow from the slow aggregation process to be swamped by the endothermic heat flow from the more rapid denaturation process.
Sinead M. Fitzsimons, Daniel M. Mulvihill, Edwin R. Morris, Food Hydrocolloids 21 (2007) 638–644

B3023 – ‘‘Melt-in-the-mouth’’ gels from mixtures of xanthan and konjac glucomannan under acidic conditions: A rheological and calorimetric study of the mechanism of synergistic gelation

The effect of acidification on a typical commercial xanthan and on pyruvate-free xanthan (PFX), alone and in gelling mixtures with konjac glucomannan (KGM), has been studied by differential scanning calorimetry (DSC) and small-deformation oscillatory measurements of storage modulus (G') and loss modulus (G''). For both xanthan samples, progressive reduction in pH caused a progressive increase in temperature of the disorder–order transition in DSC, and a progressive reduction in gelation temperature with KGM. This inverse correlation is interpreted as showing that synergistic gelation involves disruption of the xanthan 5-fold helix, probably by attachment of KGM to the cellulosic backbone of the xanthan molecule (as proposed previously by a research group in the Institute of Food Research, Norwich, UK). Higher transition temperature accompanied by lower gelation temperature for PFX in comparison with commercial xanthan at neutral pH is explained in the same way. However, an additional postulate from the Norwich group, that attachment of KGM (or galactomannans) can occur only when the xanthan molecule is disordered, is inconsistent with the observation that gelation of acidified mixtures of KGM with PFX can occur at temperatures more than 60°C below completion of conformational ordering of the PFX component (as characterised by DSC). Increase in G' on cooling for mixtures of commercial xanthan with KGM at pH values of 4.5 and 4.25 occurred in two discrete steps, the first following the temperature-course observed for the same mixtures at neutral pH and the second occurring over the lower temperatures observed for mixtures of KGM with PFX at the same values of pH. These two ‘‘waves’’ of gel formation are attributed to interaction of KGM with, respectively, xanthan sequences that had retained a high content of pyruvate substituents, and sequences depleted in pyruvate by acid hydrolysis. At pH values of 4.0 and lower, gelation of mixtures of KGM with commercial xanthan followed essentially the same temperature-course as for mixtures with PFX, indicating extensive loss of pyruvate under these more strongly acidic conditions. Mixtures prepared at pH values in the range 4.0–3.5 gave comparable moduli at room temperature (20°C) to those obtained at neutral pH, but showed substantial softening on heating to body temperature, suggesting possible applications in replacement of gelatin in products where ‘‘melt-in-the-mouth’’ characteristics are important for acceptability to the consumer.
A.A. Agoub, A.M. Smith, P. Giannouli, R.K. Richardson, E.R. Morris, Carbohydrate Polymers 69 (2007) 713–724

B3022 – Preparation, authentication, rheology and conformation of theta carrageenan

Lambda carrageenan was extracted from hand-sorted tetrasporophytes of Gigartina skottsbergii. Theta carrageenan was prepared from it by treatment with alkaline borohydride. Infrared spectroscopy showed complete, or essentially complete, conversion of 4-linked residues to the 3,6-anhydride ring form, and no detectable contamination with gelling carrageenans (iota or kappa). Optical rotation and differential scanning calorimetry (DSC) showed no evidence of conformational transitions on cooling and heating. Solutions of theta carrageenan at 2.0 wt.% in water and in 0.1 M KCl were Newtonian at 20°C, and substantially less viscous than a 1.0 wt.% solution of the lambda carrageenan precursor. Close Cox–Merz superposition was observed between steady-shear (rotational) viscosity (?) and complex dynamic viscosity (?*) at equivalent values of shear rate ( ?/s 1) and frequency (?/rad s 1), and the variation of log G'' with log ? was linear, with a slope of 1.0, strongly indicating a solution of disordered coils. The absence of double-helix formation, and associated gelation, is explained by sulfation at O(2) of 3-linked residues. A previous report of gel formation by theta carrageenan is attributed to the presence of some gelling carrageenan in the lambda sample from which it was prepared.
Jonathan P. Doyle, Persephoni Giannouli, Brian Rudolph, Edwin R. Morris, Carbohydrate Polymers 80 (2010) 648–654

B3029 – Microwave calcination of Cu/Mg/Al hydrotalcite catalyst precursor

A copper-substituted hydrotalcite (Cu1.4Mg4.4Al2.2(CO3)1.1(OH)16) has been subjected to calcination under feedback-controlled microwave heating, in which microwave power is continuously modulated to generate a defined sample temperature programme or constant sample temperature. The results show that microwave calcination results in enhanced crystallinity of the resultant oxides and spinel phase formed at high temperature, compared to conventional calcination. In addition, an additional phase, Cu2MgO3, is detected following microwave calcination, at a bulk temperature very much lower than previously reported for copper-containing hydrotalcite. The concentrations and strengths of surface basic sites are significantly higher for materials calcined using microwaves than using conventional heating. Catalytic activities in the base-catalysed transesterification of glyceryl tributyrate with methanol are also higher. We suggest that microwave calcination under feedback-control, while allowing control of material bulk temperature during calcination and preventing major temperature excursions, may allow quite large but highly localised temperature variation, for instance as water is released during dehydroxylation, which are beneficial in developing surface defects and surface basicity.
H.E. Cross, G. Parkes, D.R. Brown, Applied Catalysis A: General 429– 430 (2012) 24– 30

B3028 – Correlation between thermal induced structural and magnetic transformations in Si-rich Fe73Cu1Si16B7Nb3 metal alloy

Properties of amorphous Fe73Cu1Si16B7Nb3 foil, the Si rich metal alloy, and the foils partly crystallised after annealing, were analysed structurally and magnetically in the temperature range from 4 to 1000 K. The Fe (Si) and Fe (B) structures were identified and characterised with the crystallisation temperatures: 750 and 893 K, activation energies 460 and 580 kJ/mol. The Curie temperatures for amorphous structure: 613 K and for crystalline structures: 820, 875, 920 and 980 K were determined. It was found and analysed a delay of the sample magnetisation, determined by thermomagnetometry, with respect to structural crystallisation, determined by scanning calorimetry, which was correlated with magnetic hyperfine field, determined by transmission Mössbauer spectroscopy.
Romuald Brzozowski, Marek E. Moneta, Nuclear Instruments and Methods in Physics Research B 279 (2012) 208–211

B3027 – Measurement and prediction of binary and trenary liquid-solid equilibria of pharmaceutical and food systems

Solid-liquid equilibria are imperatively required for any design calculations of equipments like crystallizers. Since any experimental measurement is not always easy to carry out, then the modeling of such data can be of a great importance. Consequently the present work deals with measurements by means of the differential scanning calorimetry (DSC) technique, and then predictions of solid-liquid equilibria in order to calculate the necessary interaction parameters for thermodynamic activity coefficient models like the UNIFAC or the NRTL. Binary and ternary systems which may have applications in the food or the pharmaceutical fields, were considered in the present study, with water or formamide as the solvents and D-Sorbitol, D-Glucose and D-Glucose monohydrate, as the solid solute
Bitchikh K, Meniai A-H, Louaer W, Energy Procedia 18 ( 2012 ) 1152 – 1164

B3026 – Low temperature chemical reaction systems for thermal storage

This paper presents recent research works regarding the development of materials for thermal storage at temperatures below 200°C. The main idea is to utilize reversible chemical reaction systems to enable high storage densities. Current work focuses on the retrofitting of CO2 hydrates through selected additives for climate and cooling purposes and the activation of thermoreversible organic reaction systems for the waste heat utilization at low temperatures.
Baerbel Egenolf-Jonkmanns, Stefano Bruzzano, Goerge Deerberg, Matthias Fischer, Thomas Marzi, Maria Tyukavina, Jorge Salazar Gomez, Holger Wack, Barbara Zeidler-Fandrich, Energy Procedia 30 ( 2012 ) 235 – 243

B3025 – Etude thermodynamique de solutions aqueuses d’amines démixantes pour le captage du dioxyde de carbone

Les alcanolamines en solution aqueuse sont les solvants chimiques les plus utilisés pour capter le CO2. Le captage du gaz par une amine combine dans ce cas des réactions chimiques réversibles et une dissolution physique du CO2. La séparation du CO2 de la solution absorbante est ensuite possible grâce au caractère réversible des réactions chimiques. Des démonstrateurs ont été développés afin d’évaluer les capacités de ce procédé. La monoéthanolamine (MEA) en raison de sa grande réactivité avec le CO2 a été le solvant chimique utilisé dans ces premiers essais sur pilotes industriels. Le coût de la régénération de ce solvant limite son utilisation à grande échelle. Dès lors, de nouvelles voies de captage dites en rupture ont été envisagées dans le but de réduire le coût de traitement du CO2. C’est dans cette optique que le projet ACACIA (Amélioration du Captage du CO2 Industriel et Anthropique), financé par le Fond Unique Interministériel (FUI) et le Grand Lyon, a été mis en place en 2008. Le procédé en rupture étudié au cours de ce travail consiste à utiliser des solvants démixants. Il s’agit de solutions aqueuses d’amines pouvant former deux phases liquides immiscibles à une température et une concentration en CO2 données
Yohann Coulier, Thèse Université Clermont Ferrand, Décembre 2011

B3032 – Mixed transition-ion effect in the glass system: Fe2O3-MnO-TeO2

In earlier studies on phosphate and tellurite glasses containing vanadium and iron oxides, non-linear variation of physical properties as functions of the ratios of the transition ions (V/V+Fe) were observed. The most striking effect was observed with electrical conductivity, where a 3 orders of magnitude reduction in conductivity was observed at a V/V+Fe ratio of ~0.4. The effect was termed Mixed Transition-ion Effect or MTE. In phosphate glasses, however, MTE was not observed when one of the transition ions was manganese. It was concluded that Mn does not contribute to conduction in these glasses. In the present study, we demonstrate a mixed transition ion effect in tellurite glasses containing MnO and Fe2O3 (xFe2O3(0.2?x) MnO0.8TeO2 with x varying from 0 to 0.2). A maximum in the property at an intermediate composition (x=8.5 mol%), was observed in DC resistivity, activation energy, molar volume etc. Mossbauer and optical absorption (UV–VIS–NIR) measurements were performed on these glasses and the transport mechanism has been identified to be hopping of small polarons between Fe3+ (Mn3+) and Fe2+ (Mn2+) sites.
Sezhian Annamalai, Rudra P. Bhatta, Ian L. Pegg, Biprodas Dutta, Journal of Non-Crystalline Solids 358 (2012) 1380–1386

B3031 – Oxidative steam reforming of ethanol over Ir/CeO2 catalysts: A structure sensitivity analysis

A series of Ir/CeO2 catalysts of different oxide and metallic phase dispersions was investigated by XRD, TPR, HRTEM, CO2 TPD/calorimetry, in situ DRIFT spectroscopy, and oxygen isotopic exchange techniques in order to elucidate the specific influence of catalyst morphology and structure on the oxidative steam reforming (OSR) of ethanol. Structure/texture sensitivity is demonstrated on the basis of the OSR mechanism, which involves, in order: (i) ethanol adsorption on the ceria surface, (ii) partial oxidation to acetate and surface migration of the C2 intermediates along the ceria support toward the Ir particles, (iii) cracking and further oxidation into Ir carbonyls and ceria carbonates, and (iv) hydrogen and carbon monoxide desorption from the Ir particles. Structure sensitivity is established by considering two types of sites: the ceria surface sites, which are essentially pairs of oxygen vacancies and basic OH groups, as well as interfacial sites between Ir and ceria phases, involving pairs of Ir coordinately unsaturated sites (CUSs) and the aforementioned peripheral ceria sites. This structure sensitivity is revealed by TOF calculations based on these two types of sites, which correspond to the two main rate controlling steps of the ethanol OSR mechanism, namely steps (ii) and (iii). The materials considered display activity, selectivity, and resistance to aging (manifested by coke deposition and sintering) that are closely related to their initial structure and texture. Two domains in terms of iridium and ceria particle size are identified, leading either to stable and selective catalysts or to unstable and unselective catalysts. Such an original and quantified structure sensitivity analysis should prove useful for further process development.
Weijie Cai, Fagen Wang, Cécile Daniel, Andre C. van Veen, Yves Schuurman, Claude Descorme, Hélène Provendier, Wenjie Shen, Claude Mirodatos, Journal of Catalysis 286 (2012) 137–152

B3030 – Heat capacities of hydrous silicate glasses and liquids

Differential scanning calorimetry measurements made at atmospheric pressure from300 K to about 100 K above the glass transition temperature (Tg) are reported for two new series of hydrated aluminosilicate glasses and supercooled liquids forwater contents between 0 and 7.3 mol%. The compositions are synthetic iron-free analogs of tephrite and foidite lava compositions, and are depolymerized (NBO/T=0.8 and 1.5, respectively). In all cases, water exerts a marked depressing effect on Tg, in close agreementwith the results of viscosity experiments on the same samples. For glasses, the partialmolar heat capacity of water previously published for polymerized compositions (Bouhifd et al., 2006) reproduces the present data within the combined uncertainties of the experimental and model values. For the hydrous silicate glasses, the partial molar heat capacity ofwater can be thus considered as independent of composition, and insensitive to structural factors above room temperature. However, for hydrous liquids the existing data suggest two different coefficients for polymerized and depolymerized melts. In depolymerized liquids, the partial molar heat capacity of water (CpH2O) (is about 237±40 J/mol K, which is nearly three times higher than that previously determined for polymerized hydrous liquids CpH2O (?85 J/mol K for three hydrous melts with 0
M.A. Bouhifd, A.G. Whittington, A.C. Withers, P. Richet, Chemical Geology (2012)

B3033 – Multi-scale structuration of glasses: Observations of phase separation and nanoscale heterogeneities in glasses by Z-contrast scanning electron transmission microscopy

Chemical fluctuations are probed in glasses obtained with different thermal histories using scanning transmission electron microscopy in high angle annular dark field mode. Direct imaging of the glass structure is obtained at the sub-nanometer scale with Z-contrast. Macroscopic glass-in-glass separation is probed in a slowly quenched melt where chemical resolution allows the determination of the regions associated with Zr/Zn atoms. In a quickly cooled glass, exempt of macroscopic phase separation, a segregation of Zr/Zn atoms is still evidenced but on a different length scale, suggesting either the beginnings of glass separation or intrinsic features of the glass structure. Glass inhomogeneities must be taken into account to have a quantitative evaluation of nucleation processes. These “nano”-heterogeneities can be associated with the nucleation of zirconia phases, giving important clues to understand the nucleation pathways and the structural role of nucleating agents in aluminosilicate glasses.
Olivier Dargaud, Laurent Cormier, Nicolas Menguy, Gilles Patriarche, Journal of Non-Crystalline Solids 358 (2012) 1257–1262

B3037 – Effects of temperature and relative humidity on fibrillar collagen in parchment: A micro differential scanning calorimetry (micro DSC) study

Micro DSC measurements were used to investigate the synergistic effects of temperature and relative humidity on deterioration of parchment. Samples were obtained by exposing new parchments to various temperature and relative humidity atmospheres for increasing times in controlled test chambers. The impact of this accelerated ageing was assessed by measuring the thermodynamic parameters associated with the thermal denaturation of fibrillar collagen: variation of denaturation temperature, Tmax, indicated changes in collagen thermal stability, increases of DSC peak half-width, DT1/2, revealed greater thermal heterogeneity and structural disorder, whereas parallel decrease of denaturation enthalpy, DH, and DSC peak maximum height, Cp max, measured the loss of fibrillar structure. Deconvolution of DSC denaturation peaks provided a valuable illustration of both the dynamics and the pattern of the deterioration of fibrillar collagen. Impact of temperature and relative humidity on parchment integrity and stability is discussed in terms of their implications for conservation science.
Elena Badea, Giuseppe Della Gatta, Tatiana Usacheva, Polymer Degradation and Stability 97 (2012) 346-353

B3036 – Heat treatment of twin-belt cast EN AW 7075 alloy

The potential of twin-belt cast EN AW 7075 sheet for structural sheet applications was investigated with a particular emphasis on its response to the standard industrial T6 heat treatment. The twin belt cast EN AW 7075 strip is dendritic with an ?(Al)–Mg(Zn,Cu,Al)2 eutectic and predominantly Mg2Si and Al12(Fe,Cr,Mn)3Si particles at interdendritic sites. The ?(Al)–Mg(Zn,Cu,Al)2 eutectic has largely transformed into a Mg(Zn,Cu,Al)2 precipitate-rich network during the break down pass. The coarse intermetallic particles have fragmented while the fine intragranular precipitates have coarsened upon further hot rolling to a gauge of 2 mm. The predominant restoration process during rolling at 350 °C was dynamic recovery with no evidence of recrystallization. A fraction of Mg(Zn,Cu,Al)2 was replaced with Al2CuMg. Both phases dissolved during the solution heat treatment at 470 °C while the hot band has entirely recrystallized. Subsequent ageing at 121 °C for 16 h has produced a T6 hardness of 170 HB, considerably higher than that reported for the conventionally processed counterpart (150 HB). In addition to a remarkable age hardening capacity, twin belt cast EN AW 7075 alloy has enjoyed a very high resistance to age softening as inferred from a nearly T6 hardness after the industrial T73 heat treatment with an additional ageing cycle at 160 °C.
Yucel Birol, Materials Characterization, 63 (2012) 1-8

B3035 – Thermal storage material from inertized wastes: Evolution of structural and radiative properties with temperature

Hazardous wastes, such as asbestos-containing wastes (ACW) or fly ashes (FA) resulting from municipal solid waste incineration, can be converted into inert materials using plasma torch technology. Depending on the origin of the wastes and on the cooling conditions, the materials obtained at room temperature can be glassy or partially crystallized. The aim of this work is to investigate the potential valorisation of such inertized products as sensible heat material for high temperature thermal storage in thermodynamic solar power plants. Thermal stability and optical properties have been studied from room temperature up to 1000 C by infrared spectroscopy, differential scanning calorimetry and X-ray diffraction. All the studied materials are stable and present high total emissivity within the experimented temperature range. Their physical and chemical characteristics make of them to be good candidates for sensible heat storage materials.
A. Faik, S. Guillot, J. Lambert, E. Véron, S. Ory, C. Bessada, P. Echegut, X. Py, Solar Energy 86 (2012) 139–146

B3034 – Majority charge carrier reversal and its effect on thermal and electron transport in xV2O5–(1?x) As2O3 glasses

DC resistivity, thermopower and optical absorption of xV2O5–(1?x) As2O3 (0.58?x?0.93) glasses have been studied as a function of composition. The transport mechanism in these glasses has been identified to be a combination of hopping of small polarons between V4+ and V5+ sites and small bipolarons between As3+ and As5+ sites respectively. Electrical conductivity is found to be more of a function of vanadium content than arsenic concentration in the glasses, indicating that the contribution of bipolarons to the conductivity is negligible. Thermopower has also been found to be sensitive to the composition of the glasses. At lowvanadiumconcentrations, the thermopower is negative,which exhibits a sign reversal as vanadiumconcentration is increased (at x=0.7). An important feature of these glasses is that the thermopower is not a function of [V5+]/[V4+] ratio, as is normally observed in vanadate glasses, and such a phenomenon suggests that the arsenic ions (bipolarons) in these glasses contribute to the thermal transport phenomena in a significant way.
Sezhian Annamalai, Rudra P. Bhatta, Ian L. Pegg, Biprodas Dutta, Journal of Non-Crystalline Solids 358 (2012) 1019–1027

B3040 – Synthesis, structure, physical properties, and electronic structure of KGaSe2

The ternary gallium selenide KGaSe2 has been synthesized by solid-state reactions and good quality crystal has been obtained. KGaSe2 crystallizes in the monoclinic space group C2/c with cell dimensions of a = 10.878(2) Å, b = 10.872(2) Å, c = 15.380(3) Å, and ? = 100.18(3)°. In the structure, adamantane like [Ga4Se10]8? units are connected by common corners forming two-dimensional [GaSe2]? layers which are separated by K+ cations. KGaSe2 exhibits congruent-melting behavior at around 965 °C. It is transparent in the range of 0.47-20.0 ?m and has a band gap of 2.60(2) eV. From a band structure calculation, KGaSe2 is a direct-gap semiconductor. The band gap is mainly determined by the [GaSe2]? layer.
Kai Feng, Dajiang Mei, Lei Bai, Zheshuai Lin, Jiyong Yao, Yicheng Wu, Solid State Sciences 14 (2012) 1152-1156

B3039 – The role of emulsifier in stabilization of emulsions containing colloidal alumina particles

This paper focuses on the study on rheological behaviour of emulsions, stabilized by both differently modified dispersible colloidal Boehmite alumina nanoparticles and a non-ionic emulsifier. Hysteresis loop measurements and dynamic rheological measurements were carried out in linear and non-linear regimes on two different emulsion systems – water-in-oil (W/O) and oil-in-water (O/W) emulsions. Emulsion stabilized by a combination of moderately hydrophobic particles and a non-ionic emulsifier is an O/W emulsion. The addition of emulsifier improved the stability, however, did not show a significant influence on the emulsion flow behaviour. The emulsion, stabilized by both – nanoparticles and emulsifier – showed a complicated behaviour, i.e. sometimes it exhibited thixotropy or antithixotropy and sometimes both of them. Emulsion stabilized by rather hydrophobic particles and a non-polar emulsifier is a W/O emulsion. The emulsion is very homogenous and exhibited very weak thixotropy. Dynamic measurements showed that G’ was almost equal to G” and both parameters were frequency-dependent, indicating a viscous liquidlike system with little network structure if any. With addition of emulsifier, the rather elastic solid-like emulsion structure may be changed into the viscous liquid-like structure. In order to get a better understanding of relationships between rheological behaviour and microstructure, differential scanning calorimetry (DSC) results and optical microscopic images of the emulsions studied were discussed.
V. Dutschk, J. Chen, G. Petzold, R. Vogel, D. Clausse, F. Ravera, L. Liggieri, Colloids and Surfaces A: Physicochem. Eng. Aspects 413 (2012) 239– 247

B3038 – Foaming behavior of powder metallurgical Al–Sn foams

Foaming Al by the powder metallurgy technique was investigated with Sn additions (<5 wt.%). The low melting point of Sn and its immiscibility with Al creates integrity of the powder mixture during hot compaction and foaming. Furthermore, it decreases the surface tension of Al, reducing pore coalescence. Different alloying compositions and pressing and foaming parameters were evaluated. The materials were characterized using differential scanning calorimetry and thermodynamic simulation. Foam expansion and pore shape were studied by the construction of expansion maps and image analysis on foam cross-sections. It was established that, with Sn additions, not only is foaming possible at lower temperatures, but also the Sn stabilizes the foam, preventing collapse. The number of pores and sphericity values increased with increasing Sn concentrations. Optimized process parameters leading to an expansion of 375% for up to 10 min were achieved with 2–3 wt.% Sn additions, hot pressing at 300 C followed by foaming at 725 C.
Lydia Y. Aguirre-Perales, In-Ho Jung, Robin A.L. Drew, Acta Materialia 60 (2012) 759–769

B3042 – Effect of the K+, Ba2+, and Nd3+ addition to Nb2O5 on intrinsic and effective acidity in relation to biomass reactions

The mitigation of surface acidity and tuning of acid strength of niobic acid were successfully obtained by K+, Ba2+, and Nd3+ surface doping. Three series of doped samples with different amounts of each metal ion on niobic acid (2–15 atoms nm?2, 1–10 atoms nm?2, and 1–6 atoms nm?2 for K, Ba, and Nd, respectively) were prepared and characterized by various surface and bulk techniques (N2-adsorption, TGA, SEM–EDS, and UV–vis-DRS). Particular attention was paid to the acidity determination that was performed with different techniques: by conventional NH3 adsorption in a volumetric–calorimetric apparatus, by temperature-programmed desorption of PEA (2-phenylethyl-amine), and by PEA titrations in water. The acidity results obtained in water have been used to determine the sample effective acidity. The results revealed that Ba and Nd dopants were more effective than K dopant in decreasing the effective acidity of niobic acid. On the three sample series, the reactions of fructose dehydration and sucrose hydrolysis have been taken into account as model reactions to control the nature (Brønsted or Lewis acid sites, BAS, or LAS) of the catalytic acid sites still active in water. Results indicated that K+ ion doped more selectively the BAS while Ba2+ and Nd3+ ions modified more the LAS population of niobic acid.
Antonella Gervasini, Paolo Carniti, Matteo Marzo, Aline Auroux, Journal of Catalysis 296 (2012) 143–155

B3041 – Evolution of precipitation during non-isothermal ageing of an Mg–Ca–Zn alloy with high Ca content

In this work, the precipitation behaviour of an Mg–Ca–Zn alloy with high content of Ca relative to Zn was studied. Differential scanning calorimetry (DSC) was combined with transmission electron microscopy (TEM) and hardness measurement to examine the precipitate evolution in this alloy. A non-isothermal age-hardening heat treatment was performed to allow for a direct comparison to DSC results. Thermodynamic analysis aided in identifying ageing heat treatments to further de-convolute the overlapping DSC data. Results suggested the precipitation events followed sequential evolution towards the formation of two types of equilibrium phases (i.e. Mg2Ca and Mg6Ca2Zn3). Early stage decomposition of the solid solution had no observable effect on hardness, but was followed by the formation of hardening GP zones. Fine basal plates, as well as large coarse basal plates of Mg2Ca-type formed on further ageing. Contrast due to fine unidentified nanoscale precipitates was also observed in the over-aged state. These precipitates tended to disappear, while blocky Mg2Ca equilibrium phase precipitates formed as the heat treatment progressed to the highest temperature studied (i.e. 300 °C). However, the equilibrium Mg6Ca2Zn3phase was not observed when this final test temperature was achieved at the end of the non-isothermal heat treatment process.
Brian Langelier, Xiang Wang, Shahrzad Esmaeili, Materials Science and Engineering A 538 (2012) 246– 251

B3045 – Isothermal (vapor + liquid) equilibria and excess enthalpy data of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary systems at several temperatures

The vapor pressures of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary mixtures and of the three pure components were measured by means of a static device at temperatures between (263 and 333) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a third-order Redlich–Kister equation using the Barker’s method. Additionally, molar excess enthalpies, HE, for the two binary systems have been measured at 303.15 K using an isothermal flow calorimeter.
Rachida Hani, Roland Solimando, Latifa Negadi, Jacques Jose, Ahmed Ait Kaci, J. Chem. Thermodynamics 54 (2012) 83–89

B3044 – Cause and countermeasure way of rubble fires occurred after 2011 Great earthquake of Japan

This paper seeks for cause and countermeasure way of fires of huge amount of rubble which were produced after 2011 great earthquake of Japan. In 2011, we experienced many fires caused with rubbles which were produced from destroyed houses by the Great earthquake and tsunami in March 11, 2011, in Japan. Rubble includes various organic materials, and sometimes causes fires, which is used for fuel of power plants, or energy sources. It is very difficult to extinguish fire of such biomass fuel made from rubble in outdoor storage facilities. Here current studies for safety handling of these materials and proposed an evaluation method, is introduced, which is to use high sensitive calorimeters. And cause investigation work and countermeasure method, conducted by author is introduced. Our results regarding cause of fires are: initial of heat generation and fire are mostly by fermentation, and then oxidation process started after micro organism dead by high temperature, up to about 60°C. High sensitive calorimeters can detect small heat generation between room temperature and 80°C, due to fermentation or other causes. This heat generation sometimes initiated a real fire even outdoor, and produced some combustible gas. With understanding this process we recommend countermeasure way against such fires, to release heat from the pile, and prevent air entrainment into the pile to stop fermentation.
Hiroshi Koseki, Naoharu Murasawa, Yusaku Iwata, Takabumi Sakamoto, Procedia Engineering 45 ( 2012 ) 617 – 627

B3043 – Surface properties of Ru particles supported on carbon materials: A microcalorimetric study of the effects over the CO chemisorptions of residual anionic species

Chemisorption of CO combined with microcalorimetry has been applied to study the nature, number and adsorption strength distribution of surface sites exposed by carbon-supported Ru catalysts. A comparative analysis of the CO chemisorption on different Ru catalysts, prepared using two different metal precursors, RuCl3·xH2O and Ru(NO)(NO3)3, has been carried out. An activated carbon and the corresponding derivative where oxygen surface groups were incorporated, as well as carbon nanotubes and a high surface area graphite, were used as catalytic supports. Based on previous temperature programmed reduction studies, all the catalysts were reduced under hydrogen flow at 523 K or at 573 K. The CO adsorption differential enthalpy profiles show that Ru(NO)(NO3)3 precursor produces more homogeneous surface site distribution in the Ru nanocrystals, in comparison with those prepared from RuCl3, as well as higher values of enthalpies in the medium range of coverage. As a possible explanation for this effect, residual chloride species remaining after reduction treatment in the ex-chloride catalysts, that can be anchored to the Ru nanoparticles weakening the CO adsorption, have been considered. This behavior occurs for the three studied carbon supports. On the other hand, the oxygen surface groups incorporated on the activated carbon seem not to modify the CO adsorption properties of the catalysts, independently of the precursor employed
A. Guerrero-Ruiz, E. Gallegos-Suárez, L. Gonzalo-Chacón, I. Rodríguez-Ramos, Thermochimica Acta (2012)

B3050 – Manufacturing and characterization of water filled micro-composites

The goal of the present work was to manufacture water-filled micro-composites using a high pressure encapsulation process, PGSS (Particles from Gas Saturated Solutions), and to characterize the products by different analytical methods. As shell material a vegetable fat (hydrogenated Castor oil) is used. The obtained composites have tailor made properties like bulk density, particle size, morphology and water content. A special interest was laid on the distribution of water (core material) within the composites. Water distribution is studied using two different methods: H NMR and DSC. The analytical results suggest the presence of three different “types” of water: water between the particles, entrapped and bound water
L.G. Hanu, P. Alessi, A. Kilzer, S. Kareth, J. of Supercritical Fluids 66 (2012) 274– 281

B3049 – Studies of the effects of TiCl3 in LiBH4/CaH2/TiCl3 reversible hydrogen storage system

In the present study, the effects of TiCl3 on desorption kinetics, absorption/desorption reversibility, and related phase transformation processes in LiBH4/CaH2/TiCl3 hydrogen storage system was studied systematically by varying its concentration (x = 0, 0.05, 0.15 and 0.25). The results show that LiCl forms during ball milling of 6LiBH4/CaH2/xTiCl3 and that as temperature increases, o-LiBH4 transforms into h-LiBH4, into which LiCl incorporates, forming solid solution of LiBH4·LiCl, which melts above 280 °C. Molten LiBH4·LiCl is more viscous than molten LiBH4, preventing the clustering of LiBH4 and the accompanied agglomeration of CaH2, and thus preserving the nano-sized phase arrangement formed during ball milling. Above 350 °C, the molten solution LiBH4·LiCl further reacts with CaH2, precipitating LiCl. The main hydrogen desorption reaction is between molten LiBH4·LiCl and CaH2 and not between molten LiBH4 and CaH2. This alters the hydrogen reaction thermodynamics and lowers the hydrogen desorption temperature. In addition, the solid–liquid nano-sized phase arrangement in the nano-composites improves the hydrogen reaction kinetics. The reversible incorporation/precipitation of LiCl at the hydrogen reaction temperature and during temperature cycling makes the 6LiBH4/CaH2/0.25TiCl3 nano-composite a fully reversible hydrogen storage material. These four states of LiCl in LiBH4/CaH2/TiCl3 system, i.e. “formed-solid solution-molten solution-precipitation”, are reported for the first time and the detailed study of this system is beneficial to further improve hydrogen storage property of complex hydrides.
Dongan Liu, Jun Yang, Jun Ni, Andy Drews, Journal of Alloys and Compounds 514 (2012) 103– 108

B3048 – Simulated body-fluid tests and electrochemical investigations on biocompatibility of metallic glasses

This paper presents the in-vitro and electrochemical investigations of four metallic glasses (MGs) for finding potential MG-based bio-materials. The simulation body-fluid Hanks solution is utilized for testing the corrosion resistance of MGs, and microorganisms of Escherichia coli are used in testing the bio-toxicity. In addition, a simple cyclic voltammetry method is used for rapid verification of the potential electrochemical responses. It is found that the Zr-based MG can sustain in the body-fluid, exhibiting the best corrosion resistance and electrochemical stability. The microbiologic test shows that E. coli can grow on the surface of the Zr-based metallic glass, confirming the low cell toxicity of this Zr-based MG.
C.H. Li, C.H. Huang, J.F. Chuang, H.C. Lee, M.C. Liu, X.H. Du, J.C. Huang, J.S.C. Jang, C.H. Chen, Materials Science and Engineering C 32 (2012) 2578–2582

B3047 – Adsorption properties of porous materials for solar thermal energy storage and heat pump applications

The water adsorption properties of modified porous sorbents for solar thermal energy storage and heat transformation have been investigated by thermogravimetry (TG) differential thermogravimetry (DTG), microcalorimetry, measurements of water adsorption isotherms, and storage tests. A chabazite type SAPO, a dealuminated faujasite type zeolite, and a mesostructured aluminosilicate, have been synthesized and compared with common zeolites X, Y and silica gel. It has been found that optimized lattice composition and pore architecture contribute to well adapt hydrophilic properties and a beneficial steep isotherm
Jochen Jänchen, Helmut Stach, Energy Procedia 30 ( 2012 ) 289 – 293

B3046 – Solubility and partitioning of minor-actinides and lanthanides in alumino-borosilicate nuclear glass

We prepared a heterogeneous SiO2-B2O3-Na2O-Al2O3-CaO-La2O3 glass containing 11.76 wt.% AmO2. The composition of this heterogeneous material was determined from that of non-active glasses in which Am was fully substituted by Nd. For trivalent ion concentrations above the solubility limit, crystal formation occurred in the form of apatite-like silicates, this in both active and non-active glasses. Additions of Am+3 and Nd3+ led to depolymerization of the silicate network which is consistent with the modifier role expected from these cations. Thus, we can compare the incorporation mechanisms of neodymium and americium in the glassy network and within the apatite-like crystalline phases
Abdessamad Kidari, Magali Magnin, Richard Caraballo, Magaly Tribet, Franck Doreau, Sylvain Peuget, Jean-Luc Dussossoy, Isabelle Bardez-Giboirea, Christophe Jégou, Procedia Chemistry 7 ( 2012 ) 554 – 558

B3053 – Study of Live Oil Wax Precipitation with High-Pressure Micro-Differential Scanning Calorimetry

For live oils, the effect of pressure (amount of dissolved gas) on the wax appearance temperature (WAT) can be quite pronounced. Here, we describe the use of high-pressure micro-differential scanning calorimetry (HP-?DSC) as an effective technique to determine theWATfor live oils. The effect of increasing equilibration time on WAT is described and compared to predictions from a thermodynamic model
Priyanka Juyal, Tran Cao, Andrew Yen, Rama Venkatesan, Energy Fuels 2011, 25, 568–572

B3052 – Calorimetric investigation of cyclopentane hydrate formation in an emulsion

Differential scanning calorimetry (DSC) is applied to investigate the formation of cyclopentane hydrates in a water-in-oil emulsion. Protocols of cooling below the ice formation temperature and warming to a temperature above the ice and hydrate melting temperatures are applied. Cyclopentane, which forms hydrates at atmospheric pressure, is a component of the continuous oil phase in the hydrate-forming emulsion and is replaced by iso-octane to obtain a comparable ice-forming emulsion. A method based on comparing the heat flow measured by DSC for samples of identically prepared hydrate-forming and non-hydrate (ice-forming) emulsions is developed to obtain the rate of cyclopentane hydrate growth. Results are reported for a 40% water volume fraction emulsion. Experimental results lead to the conclusion that the hydrate formation takes place primarily at the interface between water drops and the continuous oil phase. In the absence of surfactants, a robust hydrate “shell” develops around the water drop limiting transport of hydrate former to the free water which remains trapped inside the hydrate layer. Direct visualization of hydrate formation in larger water drops under the influence of oil-soluble surfactants shows that the hydrate crystals have much smaller features and the appearance is hairy or mushy. A three-step mechanism – nucleation, surface growth and radial growth – is described to capture the main features of the hydrate formation process. Mechanical stresses developed in the hydrate shell due to volume expansion upon hydrate formation (a liquid–solid transition) are analyzed.
Prasad U.Karanjkar, Jae W.Lee, Jeffrey F.Morris, Chemical Engineering Science 68 (2012) 481–491

B3051 – Effect of sintering in ball-milled K2Bi8Se13 thermoelectric nano-composites

K2Bi8Se13 has many attractive features for thermoelectric applications. Recently, K2Bi8Se13-based nanocomposite materials, consisting of nano-crystalline, micro-crystalline and amorphous phases, have been fabricated based on powder technology techniques. The Seebeck coefficient has been enhanced while the thermal conductivity has been decreased presenting, thus, interesting behavior. The behavior of the materials under heat treatment conditions is now of interest, as the application of sintering process is necessary for the development of thermoelectric modules. In this work, the crystallization of the K2Bi8Se13-based nano-composites is studied using Differential Scanning Calorimetry. The results show that crystallization follows a multiple-step process with different activation energies. The thermoelectric properties are also discussed in the range that crystallization occurs
E. Hatzikraniotis, M.Ioannou, K.Chrissafis, D.Y.Chung, K.M.Paraskevopoulos, Th.Kyratsi, Journal of Solid State Chemistry 193 (2012) 137–141

B3058 – Combined effect of dynamic heat treatment and ionic strength on denaturation and aggregation of whey proteins – Part I

The aim was to investigate the effect of dynamic thermal treatment in a heat exchanger on the denaturation and aggregation of whey proteins. A 2% w/v WPI solution (pH 7.0), with or without NaCl addition (100 mM), was submitted to heat treatment at 100 °C. At low ionic strength, a nearly complete denaturation was observed, while the heat-treated samples at 100 mM ionic strength registered only 10% denaturation. It was shown that not only denaturation was reduced by the presence of NaCl, but also that the size of the aggregates formed during heat treatment was far smaller and remained essentially below 1 ?m. Surface tension measurements showed a faster adsorption and lower ? values for the non-polymerized proteins, whereas insoluble aggregates played only a poor role on the ? curves. Finally, experimental results demonstrated the strong interaction between ionic strength and dynamic thermal treatment on protein aggregation and properties.
I. Nicorescu, C. Loisel, C. Vial, A. Riaublanc, G. Djelveh, G. Cuvelier, J. Legrand, Food Research International 41 (2008) 707–713

B3057 – Formation and stability of amylose ligand complexes formed by high pressure treatment

Starch can be gelatinized during high pressure processing in the presence of water, but to a greater or lesser extent. Starch gelatinization is often accompanied by the formation of amylose complexes, in particular when a thermal treatment is used. Four different starches were considered in this study: potato, broad bean (Vicia faba), pea and tapioca. A comparison between high pressure-induced starch gelatinization (HPG) and conventional thermal gelatinization (TG) was made. In the case of broad bean starch, selected complexing molecules were considered for both thermal and high pressure treatments. Cross polarization/magic angle spinning (CP/MAS) 13C NMR, X-ray diffraction and thermal analysis were used to monitor physico-chemical changes in the structure and microstructure of starch preparations. Decanoic acid and carvacrol were selected as complexing agents to track the formation of amylose ligand complexes. It was observed that B-type starch (potato) was more resistant to pressure than the A-type starches (tapioca, broad bean and pea) considered in this study. The results showed that amylose ligand complexes were formed during high pressure treatment (20 min at 500 MPa at temperatures of 20 °C and 40 °C). Decanoic acid induced the complexing of amylose in the V6I type whatever the treatment used. On the other hand, the complexation of carvacrol appeared to depend on the temperature used during the high pressure treatment. It is assumed that carvacrol forms amorphous complexes with amylose during high pressure treatment. The amylose complexes were characterized by 13C CP/MAS NMR confirming the results obtained by X-ray analysis.
Patricia Le Bail , Benoît Chauvet, Hélène Simonin, Corinne Rondeau-Mouro, Bruno Pontoire, Marion de Carvalho, Alain Le-Bail, Innovative Food Science and Emerging Technologies, (2013)

B3056 – Aegle marmelos fruit pectin for food and pharmaceuticals: Physico-chemical, rheological and functional performance

Pectin is used in a number of foods as a gelling agent, thickener, texturizer, emulsifier and stabilizer. Bael fruit, obtained from Aegle marmelos, is a rich source of pectin. Bael fruit pectin (BFP) was extracted from ripe Bael fruits. The process yielded 15% (w/w) pure BFP. The swelling index decreased in the following order: water > pH 7.4 > pH 6.8 > pH 1.2 > HCl (0.1 N). Galacturonic acid content of 87.8%, degree of esterification of 47.2%, 17.3% methoxy groups, 0.29% acetyl groups and equivalent weight of 1209.5, indicate it to be a good gelling agent and easily amenable to derivatization. BFP exhibited a significant concentration-dependent prolongation of prothrombin time. The absence of hemagglutinating activity and antinutritional factors coupled with the activity to confer better emulsion capacity, stability and antimicrobial activity gives BFP a clear edge over commercial citrus pectin (CP) for exploitation as an additive in food and pharmaceuticals
Manish Jindal, Vineet Kumar, Vikas Rana, A.K. Tiwary, Carbohydrate Polymers 93 (2013) 386– 394

B3055 – High-temperature ferroic phase transitions and paraelectric cubic phase in multiferroic Bi0.951dFe0.9Zr0.1O3

The temperature-dependent phase transitions of Bi(0.95+?)Fe0.9Zr0.1O3 have been studied using high temperature x-ray powder diffraction together with differential scanning calorimetry measurements. The results show that Bi(0.95+?)Fe0.9Zr0.1O3 undergoes two phase transitions at 815°C and 905°C before decomposition at 920°C. It appears that Zr-doping seems to stabilize the high temperature phases in such compound. Both the sharp contraction in the unit-cell volume and enthalpy thermal hysteresis demonstrate that the ferroelectric phase transition (? ? ?) at 815°C is of first order nature. In contrast, the highest (? ? ?) phase transition at 905°C appears to be a second-order-like one. The analysis of the diffraction pattern in addition to Rietveld refinement strongly suggests a cubic symmetry for ?-phase
Jie Wei, Raphael Haumont, Romain Jarrier, Patrick Berthet, Brahim Dkhil, J. Appl. Phys. 111, 114106 (2012)

B3054 – Effects of phosphate pretreatment and hot-humid environmental exposure on static strength of adhesive-bonded magnesium AZ31 sheets

An innovative phosphate–permanganate surface treatment (PPT) was developed to improve the static strength of adhesive-bonded 4 mm thick magnesium AZ31 sheets. The phosphate coating having the chemical composition of 1.43% P, 1.63% F and 0.15% Mn (in mass %) was formed after the treatment with PPT solution which has the formulation of KMnO4, K2HPO4, Na2SiO3 and NaF. The combination of additives NaF and Na2SiO3 and the pH values in the range of 5–6 for a phosphate–permanganate solution was found to be the key elements for the formation of the phosphate coating. The appearance of the phosphate coating and corrosion resistance to 3.5%NaCl solution was assessed. To study the durability of the coating, the effect of an exposure in a hot-humid environment (96% R.H. at 40 °C) on the static strength of adhesive-bonded magnesium AZ31 was investigated. Test results showed that the phosphate coating improved not only the static strength of bonded magnesium AZ31 joints in an ambient condition but also the durability in a hot-humid environment. These results suggest that PPT surface pretreatment is capable of improving the static strength and thermal durability of adhesive-bonded magnesium AZ31 sheets
Zhong-xia Liu, Rui-na Sun, Zhi-ping Mao, Pei-chung Wang, Surface & Coatings Technology 206 (2012) 3517–3525

B3064 – Corrosion effects between molten salts and thermal storage material for concentrated solar power plants

Today, thermal energy storage (TES) is a key issue for concentrated solar power plants (CSPs). The available and mature technologies of TES do not mach all the actualised criteria for those properties. Alternative approaches have to be identified and developed to guaranty the expected extension of CSP implementations with respect to the IEA 2050 scenario. In this context, promising hybrid TES systems based upon the combination of sensible heat and liquid/solid phase change material (PCM) sub-systems are considered. For the sensible heat stage, a recycled refractory ceramic made of inertised asbestos-containing waste (IACW) is proposed. For the PCM stage, high temperature inorganic salts are considered. One major aspect of the hybrid TES is the integration of the two stages together. Therefore, the present study is focussed on the needed assessment concerning the compatibility between the IACW and the molten salts in terms of corrosion. Sulphates, phosphates, carbonates and nitrates salts have been experimented and the corrosion effects characterised by in situ NMR, ex situ X-ray diffraction and Scanning Electron Microscopy. Among those available salts, only the nitrates have shown good compatibility with IACW materials. For higher temperature levels, other salts or eutectics will have to be considered to allow hybrid TES with direct contact.
Stéphanie Guillot, Abdessamad Faik, Aydar Rakhmatullin, Julien Lambert, Emmanuel Veron, Patrick Echegut, Catherine Bessada, Nicolas Calvet, Xavier Py, Applied Energy 94 (2012) 174–181

B3063 – Solidifying incongruently melting intermetallic phases as bulk single phases using the example of Al2Cu and Q-phase in the Al–Mg–Cu–Si system

Plane front directional solidification experiments were carried out for preparing incongruently melting intermetallic phases in the quaternary alloy system Al–Cu–Mg–Si, particularly the binary Al2Cu phase and the quaternary phase (“Q-phase”). By this method, bulk samples that consist of only a single phase are generated. Sample sections consisting of 100% single phase Al2Cu and of 95% Q-phase, respectively, were obtained. The composition of the Q-phase was measured by Energy Dispersive X-ray Spectroscopy (EDX). The measured concentrations are close to the Al3Cu2Mg9Si7 composition that has recently been predicted as most stable by ab initio calculations. A peritectic temperature of 703 °C for the reaction Q ? L + Mg2Si + (Si) was determined by differential scanning calorimetry (DSC). An optimization of the Calphad database was performed considering the measured composition and peritectic temperature. For validating the optimized database, Scheil calculations were performed and compared with the experimentally determined sequence of solidifying phases.
Andrea Löffler, Joachim Gröbner, Milan Hampl, Hannes Engelhardt, Rainer Schmid-Fetzer, Markus Rettenmayr, Journal of Alloys and Compounds 515 (2012) 123– 127

B3062 – Standard enthalpies of formation of Ce–Au congruent compounds (CeAu, CeAu2, and Ce14Au51)

The enthalpies of formation of Ce–Au congruent compounds (CeAu, CeAu2, and Ce14Au51) have been determined at 1123 K and the standard enthalpies of formation at 298 K have been deduced from the measurements of enthalpy increments of single-phase samples. The following values (kJ/mole of atoms) are reported: ?fH°1123 K (CeAu) = ?75.2 ± 1.4, ?fH°298 K (CeAu) = ?76.2 ± 1.9, ?fH°1123 K (CeAu2) = ?71.3 ± 2.0, ?fH°298 K (CeAu2) = ?70.3 ± 2.2, ?fH°1123 K (Ce14Au51) = ?55.0 ± 1.7, and ?fH°298 K (Ce14Au51) = ?53.2 ± 1.9.
A. Janghorban, M. Lomello-Tafin, T. Mazingue, J. Chem. Thermodynamics 51 (2012) 65–69

B3061 – Preparation and characterization of Fe-based bulk metallic glasses in plate form

Amorphous alloys with composition (at%) Fe48Cr15Mo14C15B6Gd2 (alloy A) and Fe48Cr15Mo14C15B6Y2 (alloy B) were prepared either using pure elements (A and B1) and a commercial AISI430 steel as a base material (B2). When prepared from pure elements both alloys (A and B1) could be cast in plate form with a fixed thickness of 2 mm and variable lengths between 10 and 20 mm by means of copper-mold injection in air atmosphere. In the case of alloy B2, prepared using commercial grade raw materials, rods of 2 mm diameter were obtained. X-ray diffraction and scanning electron microscopy observations confirmed that an amorphous structure was obtained in all the as-cast samples. A minor fraction of crystalline phases (oxides and carbides) was detected on the as-cast surface. Differential scanning calorimetry measurements showed a glass transition temperature at 856 K for alloy A and 841 K for alloy B1, and an onset crystallization temperature of 887 K for alloy A and 885 K for alloy B1. In the case of alloy B2 a slightly different crystallization sequence was observed. Values of hardness (?13 GPa) and the Young modulus (?180 GPa) were measured by nanoindentation for both the alloys. The effects of adverse casting conditions (such as air atmosphere, non-conventional injection copper mold casting and partial replacement of pure elements with commercial grade raw materials) on the glass formation and properties of the alloy are discussed.
G.C. Lavorato, G.Fiore, A.Castellero, M.Baricco, J.A.Moya, Physica B407 (2012) 3192–3195

B3060 – Structural and magnetic properties of Fe76P5(Si0.3B0.5C0.2)19 amorphous alloy

Recently, bulk amorphous alloys were produced in the Fe–B–Si–P–C system with high glass forming ability, excellent magnetic properties and the advantage of containing no expensive glass-forming elements, such as Ga, Y, Cr or Nb, having, therefore, a good perspective of commercial applications. In the present work, the Fe76P5(Si0.3B0.5C0.2)19 amorphous alloy prepared by two quenching techniques has been studied. Amorphous ribbons of about 40 ?m thick were obtained by planar-flow casting together with cylinders having 1 and 2 mm diameter produced by copper mold injection casting. All the samples appear fully amorphous after X-ray diffraction analysis. A comprehensive set of thermal data (glass, crystallization, melting and liquidus temperatures) were obtained as well as a description of the melting and solidification processes. Mechanical microhardness tests showed that the samples have a hardness of 9.7 ± 0.3 GPa. Good soft-magnetic properties were obtained, including a high magnetization of 1.44 T and a low coercivity (4.5 A/m for ribbons and 7.5 A/m in the case of 1 mm rod samples, both in as-cast state). Thermomagnetic studies showed a Curie temperature around 665 K and the precipitation of new magnetic phases upon temperatures of 1000 K. Furthermore, the frequency dependence of magnetic losses at a fixed peak induction was studied. The results suggest the occurrence of a fine magnetic domain structure in bulk samples. The good soft magnetic properties of the bulk metallic glass obtained by copper mold casting for this particular Fe-based composition suggests possible applications in transformer cores, inductive sensors and other devices.
G.C. Lavorato, G. Fiore, P. Tiberto, M. Baricco, H. Sirkin, J.A. Moya, Journal of Alloys and Compounds 536S (2012) S319– S323

B3059 – Differential scanning calorimeter and infrared imaging for electrocaloric characterization of poly(vinylidene fluoride-trifluoroethylenechlorofluoroethylene) terpolymer

Electrocaloric properties of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)] terpolymer were determined by two methods. A modified differential scanning calorimeter measures the entropy variation when applying an electric field under isothermal conditions. Alternative technique consists of an infrared imaging camera that gives direct information on temperature variation in pseudo-adiabatic condition. Both techniques give similar results with a heat capacity of 1500 J/(kg K). For an electric field of 80V/lm, entropy variation was measured at 15.1 J/(kg K) and a temperature variation of 2.75K. High frequency measurement is possible using infrared imaging, and a strong frequency dependence of the electrocaloric effect was observed
Gael Sebald, Laurence Seveyrat, Jean-Fabien Capsal, Pierre-Jean Cottinet, Daniel Guyomar, Appl. Phys. Lett. 101, 022907 (2012)

B3066 – Synthesis and characterization of a novel fish scale-immobilized chitosan adsorbent—Preliminary features of dichlorophenol sorption by solution calorimetry

Brazilian Corvina fish scales were cross linked with polyglutaraldehyde and chemically modified with chitosan gel. Characterization has pointed that chitosan has good and stable adhesion on the fish scales. The sorption of dichlorophenol-2,6-indophenol (DPI) on the novel material was studied by isothermal solution calorimetry. The non-symmetric shapes of the calorimetric plots indicate that the DPI sorption sites of the adsorbent are not energetically uniform. The enthalpies of the DPI sorption processes were highly exothermic (from -536.7 to -50.9 kJ mol?1). The analysis of both the characterization of the materials and the calorimetric results has suggested that the interactions at the fish scales/DPI interface are due to surface reactions. The present work underlines the excellent features of the new fish scale-based adsorbent for use in phenol sorption applications at solid/solution interfaces.
Jackeline A. Mota, Renata A. Chagas, Eunice F.S. Vieira, Antonio R. Cestari, Journal of Hazardous Materials 229– 230 (2012) 346– 353

B3065 – Microstructural and thermophysical properties of U–6 wt.%Zr alloy for fast reactor application

The microstructural and high temperature behavior of U–6 wt.%Zr alloy has been investigated in this study. U–6 wt.%Zr alloy sample for this study was prepared by following injection casting route. The thermophysical properties like coefficient of thermal expansion, specific heat, thermal conductivity of the above alloy were determined. The hot-hardness data of the U–6 wt.%Zr alloy was also generated from room temperature to 973 K. Apart from that, the fuel-clad chemical compatibility with T91 grade steel was also studied by diffusion couple experiment. No studies have been reported on U–6 wt.%Zr alloy. This paper aims at filling up the gap on characterization and thermophysical property evaluation of U–6 wt.%Zr alloy.
Santu Kaity, Joydipta Banerjee, M.R. Nair, K. Ravi, Smruti Dash, T.R.G. Kutty, Arun Kumar, R.P. Singh, Journal of Nuclear Materials 427 (2012) 1–11

B3070 – Electrical conductivity of new zinc phosphate glass/metal composites

Zinc phosphate–glass/metal composites have been successfully prepared. Glass with composition of 45 mol% ZnO–55 mol% P2O5 (ZP) has been filled with metallic powders (nickel and cobalt). The glass matrix thermal stability has been assessed by differential thermal analysis technique. The morphology has been examined by scanning electronic microscopy, showing almost homogenous composites. Comparison between the measured and calculated densities as a function of metallic content exhibits a good coherence and allows the estimation of porosity inside the composites. X-ray diffraction analysis has revealed that the ZP-matrix phase is amorphous when the temperature treatment is below the glass transition temperature Tg. However, the principal peaks observed in the case of the composites have been assigned to the metallic crystals of nickel or cobalt fillers. It has been found that the phosphate glass phase is not affected by the growing of the metallic network. The electronic conductivity measurements versus filler volume fraction have been investigated for the first time on phosphate–glass/metal composites. This study has shown the occurrence of a conducting transition at around 30% filler volume fraction. The obtained result has been interpreted on the basis of the statistical percolation theory frame.
A. Maaroufi, O. Oabi, G. Pinto, M. Ouchetto, R. Benavente, J.M. Pereña, Journal of Non-Crystalline Solids 358 (2012) 2764–2770

B3069 – Enhanced thermal conductivity and specific heat capacity of carbon nanotubes ionanofluids

Ionanofluids represent a new and innovative class of heat transfer fluids which possess fascinating thermophysical properties. They are designable and fine-tunable through their base ionic liquids. Experimental results on effective thermal conductivity and specific heat capacity of ionanofluids as a function of temperature and concentration of multi-wall carbon nanotubes in several ionic liquids are presented. Results showed that ionanofluids exhibit superior thermal conductivity and specific heat capacity compared to those of their base ionic liquids and they further increase with the concentration of carbon nanotubes. Although the enhancement of the effective thermal conductivity of ionanofluids was found to be independent of temperature, the specific heat capacity increases significantly with increasing temperature in the range of 60–90 °C. Interaction between ionic liquid ions and dispersed nanotubes is believed to be one of the key factors for the enhanced thermal conductivity of ionanofluids.
C.A. Nieto de Castro, S.M.S. Murshed, M.J.V. Lourenço, F.J.V. Santos, M.L.M. Lopes, J.M.P. França, International Journal of Thermal Sciences 62 (2012) 34-39

B3068 – Temperature-dependent stability and DPPH scavenging activity of liposomal curcumin at pH 7.0

This paper investigated the influences of temperature on the stability and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of curcumin encapsulated in liposome at pH 7.0. Liposomal curcumin showed higher stability and DPPH scavenging activity than free curcumin at 25 °C. When temperature increased from 25 to 80 °C, liposomal curcumin degraded more pronouncedly above the phase transition temperature (Tm = 45.7 °C) of liposome than lower temperatures, suggesting a weaker curcumin protection from the liquid crystalline phase of phospholipid bilayer than that from the gel phase. Moreover, the presence of remarkable "jump" increases around Tm in the values of observed pseudo-first-order rate constant and the percent of DPPH scavenging activity of liposomal curcumin indicated that the liquid crystalline phase of phospholipid bilayer is more beneficial for curcumin to reduce DPPH. This study reveals that changing the microstructure of encapsulation carrier may effectively control the properties of phytochemicals like curcumin.
Yumeng Niu, Dan Ke, Qianqian Yang, Xiaoyong Wang, Zhiyun Chen, Xueqin An, Weiguo Shen, Food Chemistry 135 (2012) 1377–1382

B3067 – Modeling adsorption rate of organic micropollutants present in landfill leachates onto granular activated carbon

The overall adsorption rate of single micropollutants present in landfill leachates such as phthalic acid (PA), bisphenol A (BPA), diphenolic acid (DPA), 2,4-dichlorophenoxy-acetic acid (2,4-D), and 4-chloro-2-methylphenoxyacetic acid (MCPA) on two commercial activated carbons was studied. The experimental data obtained were interpreted by using a diffusional model (PVSDM) that considers external mass transport, intraparticle diffusion, and adsorption on an active site. Furthermore, the concentration decay data were interpreted by using kinetics models. Results revealed that PVSDM model satisfactorily fitted the experimental data of adsorption rate on activated carbon. The tortuosity factor of the activated carbons used ranged from 2 to 4. The contribution of pore volume diffusion represented more than 92% of intraparticle diffusion confirming that pore volume diffusion is the controlling mechanism of the overall rate of adsorption and surface diffusion can be neglected. The experimental data were satisfactorily fitted the kinetic models. The second-order kinetic model was better fitted the experimental adsorption data than the first-order model.
Raúl Ocampo-Pérez, Mahmoud M. Abdel daiem, José Rivera-Utrilla, José D. Méndez-Díaz, Manuel Sánchez-Polo, Journal of Colloid and Interface Science 385 (2012) 174–182

B3073 – CO2 Hydrate Slurry

CO2 hydrate slurry is one of the newly developed secondary cooling fluids based on CO2, an inoffensive gas in combination with water under suitable pressure and temperature conditions. A new CO2 hydrate slurry production system was built and tested. Based on previous studies, a comprehensive kinetic study of CO2 hydrates formation and growth was conducted. Solid mass fraction of CO2 hydrate slurry was determinated. The experimental results show that besides pressure and temperature, density and apparent viscosity change can also be good indicators of the hydrate formation. The results have shown that hydrate creation through the heat exchanger by super cooling of the saturated CO2 solution is feasible. Continuous CO2 hydrate slurry formation and dissociation by heat exchanger was proved to be feasible. The pressure drop of CO2 hydrate slurry with different solid mass fraction on heat exchanger as function of steady flow mean velocities were presented and verified. The stability of CO2 hydrate slurry was examined. CO2 hydrate slurry displayed very good stability at steady state during 11.5 hours running test. Longer stability period should be expected if the running conditions are maintained.
Jin Hu, Osmann Sari, Cyril Mahmed, Raffaele Cereghetti, Paul Homsy, Final report, Yverdon les Bains (Switzerland), July 2010

B3072 – Thermodynamic properties of fluoranthene: An experimental and computational study

Vapour pressures of both crystalline and liquid (including super-cooled liquid) phases of fluoranthene were measured using a pressure gauge (capacitance diaphragm manometer) over the temperature range (348.8 to 404.3) K yielding accurate determination of enthalpies and entropies of sublimation and vaporisation. Enthalpy of sublimation was also determined using Calvet microcalorimetry. The enthalpy of fusion was derived from vapour pressure results and from d.s.c. experiments. Static bomb calorimetry was used to determine the enthalpy of combustion of fluoranthene from which the standard enthalpy of formation in the crystalline phase was calculated. The enthalpy of formation in the gaseous phase was calculated combining the result derived for the crystalline phase with the enthalpy of sublimation determined from the vapour pressure measurements. Computational results of the enthalpies of formation of fluoranthene and fluorene were also calculated at the G3 and G4 levels, and compared with the experimental values.
Manuel J.S. Monte, R. Notario, Sónia P. Pinto, Ana I.M.C. Lobo Ferreira, Maria D.M.C. Ribeiro da Silva, J. Chem. Thermodynamics 49 (2012) 159–164

B3071 – Yeast (1-3),(1-6)-d-glucan films: Preparation and characterization of some structural and physical properties

Cell wall polysaccharide suspensions (mainly ?-glucan) was isolated from baker's yeasts (Saccharomyces cerevisiae) and used for the preparation of films. Glycerol was added as a plasticizer. Purity and composition of the films were tested by elemental analysis, enzymatic assay of ?- and ?-glucans, monosaccharide composition analysis (total hydrolysis, HPAEC) and vibration spectroscopy (FTIR, FT Raman). Surface properties and the degree and type of crystallinity, together with ageing effects, were estimated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Mechanical and thermal properties were characterized by tensile tests and difference scanning calorimetry (DSC), respectively. The prepared films were water insoluble, compact, non-porous, exhibit no pronounced crystallinity and consist of granular-like and fibre microstructures, which could be assigned as cell wall residues and released polysaccharide macromolecules. Certain structural changes in the film surface during one-year shelf storage can be related to reorientation and decomposition of surface macromolecules due to reaction with the ambient atmosphere, rather than to crystallization phenomena.
Miroslav Novák, Andriy Synytsya, Ondrej Gedeon, Petr Slepicka, Václav Procházka, Alla Synytsya, Jirí Blahovec, Anna Hejlová, Jana Copíková, Carbohydrate Polymers 87 (2012) 2496– 2504

B3074 – A study on the nature of intermolecular links in the cryotropic weak gels of hyaluronan

In this study, the influence of acidification and salting effect on the properties of hyaluronan (HA) aqueous solutions and cryotropic weak gels were investigated by dynamic rheometry, polarizing and optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and FTIR spectroscopy. The forming mechanism of HA cryotropic weak gels was also discussed. Experimental results indicated that the HA weak gel showing a thermoreversible property was constructed by entangled bundle-like structures that could be melted at elevated temperature above 70 °C, and that the junction knots of three-dimensional polymeric network were not the ordinary microcrystalline zones that are generally of detectable crystallinity and thermal effect. The intermolecular hydrogen bonding induced from –COOH and –NHCOCH3 in HA chains played a predominant role in respect to the network formation and stabilization of HA weak gel.
Tu Luan, Lijiao Wu, Hongbin Zhang, You Wang, Carbohydrate Polymers 87 (2012) 2076– 2085

B3077 – Natural Gas Hydrate Formation and Decomposition in the Presence of Kinetic Inhibitors. 1. High Pressure Calorimetry

The effect of kinetic inhibitors, both chemical (PVP and H1W85281) and biological (type III antifreeze protein), on natural gas hydrate formation was investigated using high pressure differential scanning calorimetry (HP-DSC). The presence of inhibitors decreased the overall formation of methane/ethane/propane hydrate compared to systems without added inhibitors. As well, all of the inhibitors significantly delayed hydrate nucleation as compared to water controls. However, the two classes of inhibitors were distinguished by the formation of hydrates with different stabilities. A single hydrate melting peak was seen with the antifreeze protein (AFP), and this was consistent after recrystallization. In contrast, multiple hydrate melting events, some indicating the formation of hydrate structures with high stability, were observed in the presence of the chemical inhibitors, and these varied depending on the crystallization cycle. This heterogeneity suggests that the use of these chemical inhibitors (PVP and H1W85281) may present a special challenge to operators depending upon the gas mixture and environmental conditions and that AFPs may offer a more predictable, efficacious solution in these cases
Nagu Daraboina, John Ripmeester, Virginia K. Walker, Peter Englezos, Energy Fuels 2011, 25, 4392–4397

B3076 – Experimental verification of hematite ingot mould heat capacity and its direct utilisation in simulation of casting process

Heat capacity of alloys (metals) is one of the crucial thermophysical parameters used for process behaviour prediction in many applications. Heat capacity is an input variable for many thermodynamical (e.g. Thermocalc, Pandat, MTData, …) and kinetic programs (e.g. IDS-Solidification analysis package, …). The dependences of heat capacity on common variables (temperature, pressure, ...) are also commonly used as the input data in software packages (e.g. ProCast, Magmasoft, ANSYS Fluent, …) that are applicable in the field of applied research for simulations of technological processes. It follows from the above that the heat capacities of materials, alloys in our case, play a very important role in the field of basic and applied research. Generally speaking, experimental data can be found in the literature, but corresponding (needed) data for the given alloy can very seldom be found or can differ from the tabulated ones. The knowledge of proper values of heat capacities of alloys at the corresponding temperature can be substantially used for addition to and thus towards the precision of the existing database and simulation software. This study presents the values of Cp measured for the hematite ingot mould and comparison of the measured data with the Cp values obtained using the software CompuTherm with respect to simulation of technological casting process
Bedrich Smetana, Monika Zaludova, Marketa Tkadleckova, Jana Dobrovska, Simona Zla, Karel Gryc, Petr Klus, Karel Michalek, Pavel Machovcak, Lenka Rehackova, J Therm Anal Calorim (2013) 112, 473–480

B3075 – Microstructure study of liposomes decorated by hydrophobic magnetic nanoparticles

Magnetoliposomes, consisting of liposomes and magnetic nanoparticles (MNPs), have been tailored as very promising delivery vehicles in biotechnology and biomedicine applications. In this paper, liposomes with hydrophobic MNPs were prepared. The hydrophobic MNPs were successfully embedded in the lipid bilayer, which was proved by the results obtained from transmission electron microscope, atomic force microscope, differential scanning calorimetry and steady state fluorescence measurements. Moreover, systematic researches were carried out to investigate the effects of hydrophobic MNPs concentration on the morphology and microstructure of liposomes. The results show that the lipid bilayer was saturated with the hydrophobic MNPs when the mass ratio of MNPs to lipid reached 0.002.
Dan Qiu, Xueqin An, Zhiyun Chen, Xingyuan Ma, Chemistry and Physics of Lipids 165 (2012) 563– 570

B3081 – A temperature-dependent model for the measurement of the thermal conductivity of liquids, using a microca

A study of a steady-state method for thermal conductivity measurements of liquids has been carried out. It uses a C80D differential micro-calorimeter from Setaram (France), with special designed vessels containing a heating resistance. The thermal conductivity k of a liquid sample is determined as a function of the heat flow measured by the calorimeter, using an expression whose coefficients are found through the calibration with three reference liquids. These coefficients change with the calorimeter temperature, so the calibration has to be performed at each temperature. In this work, it has been verified that the coefficients’ temperature variations can be justified by the thermal properties of the calorimeter components. A new model valid for all temperatures has been developed, taking into account those factors. This new model confirms the physical meaning of the procedure, brings down the number of measurements required for the calibration, and slightly reduces the uncertainty of the results.
B Barbes, E Blanco, C Casanova, R Paramo, Meas. Sci. Technol. 22 (2011) 045401

B3080 – Microcalorimetric adsorption studies of highly loaded Co–ZrO2/SiO2 catalysts for Fischer–Tropsch synthesis

Highly loaded Co/SiO2 catalysts were prepared by a co-precipitation technique with an n-butanol drying process for Fischer–Tropsch synthesis (FTS). With the increase in cobalt loading from 20% to 80%, the FTS activity of the catalysts increased greatly. The addition of ZrO2 improved the dispersion of cobalt and promoted the adsorption of H2 and CO on cobalt. The preadsorbed H atoms significantly enhanced the adsorption of CO and C2H4, especially on cobalt promoted by ZrO2. While the adsorption of C2H4 onto clean cobalt led to the formation of ethylidyne, ?- and di-?-bonded C2H4 might form on the CO-preadsorbed 80%Co/SiO2 and 80%Co–8%ZrO2/SiO2, respectively. The presence of ZrO2 strengthened the bonding of molecularly adsorbed ethylene and increased its uptake on CO-preadsorbed cobalt, which might be why the 80%Co–8%ZrO2/SiO2 exhibited such high activity for the hydrogenation of CO to heavy hydrocarbons.
Liang Chen, Jianyi Shen, Journal of Catalysis 279 (2011) 246–256

B3079 – Amine-modified MCM-41 mesoporous silica for carbon dioxide capture

This paper presents an easy way to obtain a material with CO2 sorption properties by using commercially available MCM-41. In order to increase MCM-41 CO2 sorption capacity, 2.48 mmol g?1 of amine groups were anchored onto silica surface. A few carefully chosen spectroscopic techniques – namely infrared diffuse reflectance spectroscopy and solid-state 13C and 29Si nuclear magnetic resonance – demonstrated that amino groups are covalently bounded to mesoporous silica and not just adsorbed on it. CO2 uptake by the samples was investigated by microcalorimetry experiments performed at 30 °C. The amine functionalized material, MCM-41-NH2, exhibited a higher uptake of CO2 at very low pressures compared with the nongrafted material. The modified material presented heat of adsorption of ?98 versus ?32 kJ mol?1 for MCM-41 at low pressures. The mode of CO2 uptake in MCM-41-NH2 was both chemisorption at low pressures and physisorption at high pressures. Solid-state 13C nuclear magnetic resonance performed on amine-functionalized MCM-41 after CO2 adsorption experiments, showed a signal attributed to carbamate that was formed as a product of the reaction between CO2 and amine groups. This material has potential for CO2 recovery at low pressures/concentrations.
Marília R. Mello, Delphine Phanon, Gleiciani Q. Silveira, Philip L. Llewellyn, Célia M. Ronconi, Microporous and Mesoporous Materials 143 (2011) 174–179

B3078 – Formation of Graphene Oxide Nanocomposites from Carbon Dioxide Using Ammonia Borane

To efficiently recycle CO(2) to economically viable products such as liquid fuels and carbon nanomaterials, the reactivity of CO(2) is required to be fully understood. We have investigated the reaction of CO(2) with ammonia borane (AB), both molecules being able to function as either an acid or a base, to obtain more insights into the amphoteric activity of CO(2). In the present work, we demonstrate that CO(2) can be converted to graphene oxide (GO) using AB at moderate conditions. The conversion consists of two consecutive steps: CO(2) fixation (CO(2) pressure < 3 MPa and temperature < 100 °C) and graphenization (600-750 °C under 0.1 MPa of N(2)). The first step generates a solid compound that contains methoxy (OCH(3)), formate (HCOO) and aliphatic groups while the second graphenization is the pyrolysis of the solid compound to produce graphene oxide-boron oxide nanocomposites, which have been confirmed by micro-Raman spectroscopy, solid state (13)C and (11)B magic angle spinning-nuclear magnetic resonance (MAS-NMR), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Our observations also show that the mass of solid product in CO(2) fixation process and raw graphene oxide nanocomposites is twice and 1.2 times that of AB initially charged, respectively. The formation of aliphatic groups without using metal-containing compounds at mild conditions is of great interest to the synthesis of various organic products starting from CO(2.).
Junshe Zhang, Yu Zhao, Xudong Guan, Ruth E. Stark, Daniel L. Akins, Jae W Lee, J Phys Chem C Nanomater Interfaces. 2012 January 17; 116(3) 2639–2644

B3085 – High performance storage composite for the enhancement of solar domestic hot water systems. Part 1: Storage material investigation

This work aims to evaluate the performance of a solar domestic hot water (SDHW) system including a latent storage material. The originality of our approach consists to place a composite made of compressed expanded natural graphite (CENG) and phase change material (PCM) directly inside a flat plate solar collector in order to replace the traditional copper-based solar absorber. According to this target, the study is composed of two steps: the composites preparation and characterization; and the analysis of the system to achieve optimal integration of the material in the process. The present paper is focused on the selection of the most promising composite to implement in the solar collector. In order to reach this objective, several composites based on CENG and various storage materials (paraffin, stearic acid, sodium acetate trihydrate and pentaglycerin) have been elaborated and characterized. The synthesis of all these measurements allowed us to select three composites whose characteristics match their integration into a solar thermal collector.
D. Haillot, V. Goetz, X. Py, M. Benabdelkarim, Solar Energy 85 (2011) 1021–1027

B3084 – Thermophysical study of sandstone reservoir rocks

Thermal conductivity of both dry and fully water (brine solution, 5 g/l NaCl concentration) saturated rocks have been measured for 35 sandstone core samples obtained from both Hungary and Egypt. Measurements are executed in order to look for thermal anisotropy. The rock porosity, permeability and density were measured beside thermal conductivity, while some correlations were performed in order to differentiate among clayey laminated, flaser bedding and clean sandstone reservoirs. There is a very close correlation among thermal conductivity, rock porosity, bulk density, gas permeability and ultrasonic wave velocities for non laminated clean sandstones, while in banded sandstone reservoirs these relations show more than one trend giving a strong impression indicating the presence of more than one grain–fabric system and/or complex diagenesis. The relationship among the measured thermal conductivity for the core axis, the top and bottom are close and homogeneous for isotropic clean non laminated Szolnok sandstones, while they are vary in a wide range for banded and laminated Bahariya sandstone samples. The measured specific heat capacity indicates that some banded sandstone samples of the Bahariya Formation have bound water appears at 100 °C and giving low specific heat capacity value. This bound water can acted on all petrophysical parameters especially electrical properties. The prediction of specific heat capacity and heat flow from the reservoir temperature is possible using the calculated multi-regression and linear regression models.
Abdel Moktader A. El Sayed, Journal of Petroleum Science and Engineering 76 (2011) 138–147

B3083 – Conception, construction, expérimentation et modélisation d’un banc d’essias grandeur nature de climatisation utilisant un fluide frigoporteur diphasique à base d’hydrates de TBAB

Ces travaux de thèse ont donc consisté à adapter une technologie de réfrigération disponible sur le marché européen au domaine de la climatisation. Le fluide utilisé est une solution de TBAB (Bromure de Tetra-ButylAmmonium) qui est une solution aqueuse dont la température de cristallisation à pression atmosphérique peut être ajustée entre environ 6 et 12°C. Le dispositif expérimental conçu et construit est donc un prototype industriel de taille réelle capable de climatiser 4 pièces. A la fois démonstrateur industriel et banc d’essais instrumenté, il est destiné à mener à bien des séances d’essais afin de démontrer la faisabilité du procédé, de diagnostiquer des améliorations et de prévoir de nouvelles évolutions. Parallèlement aux travaux de construction et aux séances d’essais, des mesures complémentaires concernant certaines caractéristiques thermo-physiques des sorbets d’hydrates de TBAB ont été menées en laboratoire. Enfin, un outil de modélisation a également été développé afin de rattacher les expériences à des phénomènes thermo-physiques théoriques. Cette modélisation a pour but d’être un outil prédicatif à la conception de nouvelles installations et au développement du prototype.
Jérôme Douzet, Thèse École Nationale Supérieure des Mines de Saint-Étienne, Juillet 2011

B3082 – Nitrogen-containing mesoporous carbons prepared from melamine formaldehyde resins with CaCl2 as a template

Melamine formaldehyde resins were synthesized with encapsulated CaCl(2) as a template. Carbonization at high temperatures led to the formation of carbon materials containing N atoms. Washing with de-ionized water removed encapsulated CaCl(2), resulting in the formation of mesopores (3-30 nm) with the high surface areas (770-1300 m(2)/g). The template can be recycled and the method is simple and cost effective as compared to the hard template techniques. The mesoporous carbons containing nitrogen (NMC) thus prepared exhibited the amphipathic surfaces (both hydrophilic and lipophilic) and adsorbed great amount of water and benzene. In addition, the incorporated N atoms exhibited quite strong basicity for the adsorption of great amount of SO(2).
Yuan Huang, Feng Yang, Zheng Xu, Jianyi Shen, Journal of Colloid and Interface Science 363 (2011) 193–198

B3086 – The influence of temperature on the adsorption of CTAB on coals

The influence of temperature on the adsorption behavior of the cationic surfactant cetyltrimethyl amonium bromide (CTAB) has been studied. Batch mode was used for the adsorption of CTAB on three different types of coal, namely oxidative altered coal (BO), subbituminous coal (SB) and bituminous coal (BC). Adsorption from aqueous solutions was carried out at 25, 40, 60 and 80 °C. The linear as well as nonlinear regression of experimental data confirmed that the adsorption process can be described using the Langmuir adsorption theory of monolayer coverage. Thus, the equilibrium constant of adsorption could be calculated from the Langmuir binding constant b. Further, thermodynamic parameters such as enthalpy ?Hads, entropy ?Sads and Gibbs energy ?Gads were determined from the dependence of the b constant on temperature. The calculated thermodynamic parameters indicate that the adsorption of CTAB on coals is an exothermic (?Hads < 0) and spontaneous (?Gads < 0) process. It was proved that the adsorption capacity of CTAB on coal increased with a rise in temperature for all the studied samples; the highest adsorption capacity was observed for the oxidative altered coal. Moreover, a close relationship between the adsorption capacity and the critical micelle concentration (CMC) of CTAB has been discovered. In addition, measuring the zeta potential proved that the adsorbed amount of CTAB on the coal surface corresponded to the zeta potential value. Addition of the cationic surfactant (CTAB) affects the value of ?-potential, making the zeta potential values more positive
Roman Marsalek, Jan Pospisil, Boleslav Taraba, Colloids and Surfaces A: Physicochem. Eng. Aspects 383 (2011) 80–85

B3093 – Drug release from calcium and zinc pectinate beads: Impact of dissolution medium composition

The aim of this study was to investigate drug release from calcium and zinc pectinate beads and to understand the impact of medium electrolytes during drug transfer. A potential drug carrier for colonic drug delivery (rutin) was prepared with calcium and zinc pectinate beads and was tested in three different simulated intestinal fluids (pH 7.3) with phosphates (Sorensen's and Mc Ilvaine's buffers) and without phosphates (Tris-buffer). According to swelling studies and zinc ions release, it was showed that zinc ions keep adhering to the bead surface. Drug release and swelling behaviour from the two dosage forms depend not only on pH and ionic strength but also on the electrolytes there were in the dissolution medium. In calcium pectinate beads, rutin release was faster when phosphate buffers were used because precipitates (CaHPO4) were formed. This precipitate has a pumping effect on the calcium ions, destabilizing the gel structure and enhancing rutin release. In the case of zinc pectinate beads, two kinds of precipitate can be developed depending on the electrolytes composition. The development of Zn3(PO4)2 with a coating property reduced rutin release (Sorensen's buffer). On the other hand, development of ZnHPO4 has the pumping effect of zinc ions coming from the beads which increased rutin release (Mc Ilvaine's buffer).
Ali Assifaoui, Odile Chambin, Philippe Cayot, Carbohydrate Polymers 85 (2011) 388–393

B3092 – Enthalpies of sublimation of ferrocene and nickelocene measured by calorimetry and the method of Langmuir

A quick and accurate methodology that is based on Langmuir’s equation and that is developed by utilising a DSC7 device is proposed for the measurement of the enthalpies of sublimation of substances characterised by vapour pressures of approximately 1.0 Pa at room temperature. The procedure was applied to ferrocene and nickelocene; the accuracy and uncertainty associated with the experimental results show that the reliability of the developed indirect method is comparable to the direct calorimetric measurements also performed in this work. Furthermore, the melting data and crystal-phase heat capacities for both metallocenes were calorimetrically measured, whereas the gas-phase heat capacity for each metallic bis(cyclopentadienyl) was theoretically estimated by DFT calculations.
Aarón Rojas, María Teresa Vieyra-Eusebio, J. Chem. Thermodynamics 43 (2011) 1738–1747

B3091 – Microencapsulation of a cooling agent by interfacial polymerization: Influence of the parameters of encapsulation on poly(urethane–urea) microparticles characteristics

A series of polyurea-urethane microparticles containing xylitol were synthesized by interfacial polymerization from reaction between diphenyl methylene diisocyanate (MDI) and xylitol. This research was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation step and during the shell formation using contact angle measurement, Fourier-transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analyses. By carefully analyzing the influencing factors stirring rate and feeding weight ratio of core/shell monomers, the optimum synthetic conditions were found out. The results show that core/shell weight ratio influences not only the shell formation mechanism but also the mean diameter, microcapsule morphology, the encapsulation yield and the xylitol content. Thus, the choice of a core/shell weight ratio of 77.0-23.0 is the most suitable to obtain high encapsulation yield and xylitol loading content.
F. Salaün, G. Bedek, E. Devaux, D. Dupont, L. Gengembre, Journal of Membrane Science 370 (2011) 23–33

B3090 – Influence of the washings on the thermal properties of polyurea-urethane microcapsules containing xylitol to provide a cooling effect

In this report, the preparation and performance of microcapsules interacting with the absorbed water to promote a cooling effect were investigated. The microcapsules containing xylitol were prepared from xylitol and diphenyl methylene diisocyanate (MDI) by an interfacial polymerization process. The microencapsulated xylitol was characterized by scanning electron microscopy (SEM) to illustrate its porous surface structure and its morphology. The influence of the drying process after washing was analyzed by differential scanning calorimetry (DSC) prior to the determination of the heat of solution. The results show the perspectives of the usage of these microcapsules as a reversible cooling agent for moisture management.
F. Salaün, G. Bedek, E. Devaux, D. Dupont, Materials Letters 65 (2011) 381–384

B3089 – Catalytic steam reforming of methane under conditions of applicability with Pd membranes over supported Ru catalysts

Three Ru catalysts supported on SiO2, ZrO2–SiO2 and ZrO2–La2O3 have been prepared, characterized and tested in the methane steam reforming (SR) reaction, and for comparative purposes a Ni/SiO2 catalyst has also been studied. Conditions of catalytic studies have been selected for the subsequent application in a hydrogen extraction Pd membrane reactor. That is, reaction temperatures in the range of 400–550 °C and with different amounts of catalyst in order to work under and/or close to the equilibrium conversion conditions. All the supported Ru samples exhibit high catalytic activity and similar CO and H2 yields. Finally these catalysts are fully stable under reaction conditions at 550 °C for 15 h, while the Ni/SiO2 sample suffers a significant deactivation. The main deactivation process affecting this latter catalyst is the carbon deposition of partially dehydrogenated intermediates as detected by Raman spectroscopy. Hence, these Ru catalysts appear to be suitable for application combined with metallic (Pd) membrane.
M.A. Soria, C. Mateos-Pedrero, I. Rodríguez-Ramos, A. Guerrero-Ruiz, Catalysis Today 171 (2011) 126– 131

B3088 – The poisoning level of Pt/C catalysts used in PEM fuel cells by the hydrogen feed gas impurities: The bonding strength

Proton exchange membrane fuel cells (PEMFCs) most likely will use reformed fuel as the primary source for the anode feed despite it nearly always contains carbon monoxide or ammonia. In this paper, the microcalorimetry technique was employed to study and compare the poisoning effect of pollutants such as CO and NH3 on three commercial carbon-supported platinum catalysts with high Pt loading, aimed to be used in PEMFCs applications. Microcalorimetric measurements were performed at 80 °C and the results were compared with those obtained from hydrogen adsorption in similar conditions. All the catalysts exhibited significantly higher differential heats of CO adsorption in comparison with NH3 and hydrogen adsorption, indicating that carbon monoxide will be primarily adsorbed in case of co-adsorption, while ammonia and hydrogen will compete in the adsorption process on the same type of active sites. The irreversibly (chemically) amount of adsorbed molecules on Pt/C surfaces decreases in the order: CO >> NH3 > H2.
Georgeta Postole, Aline Auroux, International Journal of Hydrogen Energy 36 (2011) 6817-6825

B3087 – Impact of aggregate coating with a PEC elastomer on properties of lightweight flax shive concrete

Lightweight concrete becomes an important subject of research because of its insulating properties. The main objective of this research is to present a process improving the flax shive behaviour in a cement matrix. Flax shives stem from flax culture. It is the major product (50% of biomass weight). To be used as aggregates, shives should have a hydrophobization treatment. The aim of this work is the treatment of shives with a biodegradable elastomer: poly(PEG-co-CA). This elastomer is synthesized by the polycondensation of polyethylenglycol (PEG) and citric acid (CA). After their treatment with PEC elastomer, flax shives show a decrease in water absorption. Then, they are incorporated in a cement matrix. Mechanical properties, thermal properties and behaviour towards water (dimensional variations) of concrete are determined. The shive treatment shows an improvement in compressive and flexural strengths but an increase in thermal conductivity. The extreme dimensional variations (EDVs) and drying shrinkage (DS) decrease also with concrete prepared with treated shives compared to the standard. Overall the lightweight concrete obtained exhibits performances close to those of wood concrete.
Mahmoud Khazma, Adeline Goullieux, Rose Marie Dheilly, Boubker Laidoudi, Michèle Queneudec, Industrial Crops and Products 33 (2011) 49–56 Contents lists

B3096 – Enhanced interfacial properties of novel amino acid-derived surfactants: Effects of headgroup chemistry and of alkyl chain length and unsaturation

Amino acid-derived surfactants have increasingly become a viable biofriendly alternative to petrochemically based amphiphiles as speciality surfactants. Herein, the Krafft temperatures and critical micelle concentrations (cmc) of three series of novel amino acid-derived surfactants have been determined by differential scanning microcalorimetry and surface tension measurements, respectively. The compounds comprise cationic molecules based on serine and tyrosine headgroups and anionic ones based on 4-hydroxyproline headgroups, with varying chain lengths. A linear dependence of the logarithm of cmc on chain length is found for all series, and in comparison to conventional ionic surfactants of equal chain length, the new amphiphiles present lower cmc and lower surface tension at the cmc. These observations highlight their enhanced interfacial performance. For the 18-carbon serine-derived surfactant the effects of counterion change and of the presence of a cis-double bond in the alkyl chain have also been investigated. The overall results are discussed in terms of headgroup and alkyl chain effects on micellization, in the light of available data for conventional surfactants and other types of amino acid-based amphiphiles reported in the literature
Rodrigo O. Brito, Sandra G. Silva, Ricardo M.F. Fernandes, Eduardo F. Marques, José Enrique-Borges, Maria Luísa C. do Vale, Colloids and Surfaces B: Biointerfaces 86 (2011) 65–70

B3095 – Protein denaturation and water–protein interactions as affected by low temperature long time treatment of porcine Longissimus dorsi

The relationship between water–protein interactions and heat-induced protein denaturation in low temperature long time (LTLT) treated pork Longissimus dorsi was investigated by combining low-field NMR T2 relaxometry with DSC measurements and measures of shrinkage of porcine Longissimus dorsi heated to 53 °C, 55 °C, 57 °C and 59 °C for either 3 or 20 h. Water within the myofibrils, measured by NMR T21 relaxation times, was affected by both temperature and holding time during LTLT treatment between 53 °C and 59 °C. The changes in NMR T21 relaxation times were associated with decreased fiber diameter and increased cooking loss, revealing a relationship between transverse shrinkage, water–protein interactions and cooking loss. DSC measurements revealed a concomitant decrease in ?H68 °C, which suggests impact of collagen denaturation on the retention of water within the meat during LTLT treatment. Furthermore, a decrease in ?H75 °C suggested that prolonged cooking (20 h) resulted in actin denaturation leading to decreased T21 relaxation times and higher cooking loss.
Line Christensen, Hanne C. Bertram, Margit D. Aaslyng, Mette Christensen, Meat Science 88 (2011) 718–722

B3094 – Temperature and time effects on the structural properties of a non-aqueous ethyl cellulose topical drug delivery system

The structural properties of ethyl cellulose and propylene glycol dicaprylate mixtures were investigated with a view to facilitating use of the system as excepient for topical drug delivery. The working protocol included small-deformation dynamic oscillation in combination with the principle of time–temperature superposition, micro and modulated differential scanning calorimetry, wide-angle X-ray diffraction patterns, infrared spectroscopy, and optical profile analysis in the form of gel particle roughness. In contrast to thermoreversible gelation upon heating of aqueous ethyl cellulose solutions reported widely in the literature, replacing water with propylene glycol dicaprylate and mixing with the polymer yields gels that revert to the solution state with increasing temperature. Time effects were also probed; the continuous increase in viscoelasticity of preparations as a function of time of observation at ambient temperature was accompanied by structural disintegration of the polymeric particles. This was rationalized by proposing that specific polymer–solvent interactions result with aging in particle erosion and the release of polymeric strands that are able to form a three-dimensional structure. It was thus documented that the time–temperature equivalence was active in the system producing a rubbery state in the master curve of viscoelasticity, which extends from ambient to subzero temperatures and should facilitate pharmaceutical applications.
Lilia Bruno, Stefan Kasapis, Vinita Chaudhary, Keat Theng Chow, Paul W.S. Heng, Lai Peng Leong, Carbohydrate Polymers 86 (2011) 644– 651

B3100 – Rheology and microstructure of k-carrageenan under different conformations induced by several concentrations of potassium ion

Rheology, micro-DSC and confocal microscopy were used to study the effect of potassium ion on the viscoelastic behavior, disorder–order transition and microstructure, respectively, of ?-carrageenan in solution under different conformations at 60, 25 and 9 °C. At 60 and 25 °C the rheological behavior of 0.5% ?-carrageenan with 0–80 mmol/dm3 and 0–5 mmol/dm3 KCl, respectively, was typical of viscoelastic solutions of random coiled polymers. At 9 °C and below a critical ionic concentration of about 7.0 mmol/dm3, ?-carrageenan adopted an ordered conformation in which helical structures did not aggregate and hence did not form self-supporting gels. Changes in polysaccharide stiffness were estimated from intrinsic viscosity variations as a function of ionic content. In the ordered state, the stiffness was higher than in the disordered state, whereas a liquid-like viscoelastic behavior was still exhibited. In 0.5% ?-carrageenan at 25 °C, increasing KCl from 0 to 300 mmol/dm3 produced gels of increasing rigidity. However, above 100 mmol/dm3 such increase was marginal. Confocal images evidenced a three-dimensional network whose continuity depends on polysaccharide and salt concentrations. These observations are consistent with the rheological behavior of the self-supporting gels obtained with ?-carrageenan concentrations in the range of 0.05–1%.
M.C. Núñez-Santiago, Alberto Tecante, Catherine Garnier, Jean Louis Doublier, Food Hydrocolloids 25 (2011) 32-41

B3099 – Physical and chemical properties of ultrasonically, spray-dried green banana (Musa cavendish) starch

Ultrasonic wave propagation and the spray dryer technique were applied to study their effect on the physical and chemical properties of green banana starch. The results showed high resistant starch content, which was reduced by ultrasound treatment and also by spray drying. Both techniques increased the solubility, swelling power and water absorption capacity. The gels exhibited non-Newtonian shear-thinning behavior, since flow behavior index was less than one (n < 1). Ultrasound wave propagation reduced yield stress and consistency coefficient in starch gels. Under oscillatory shear, all gels exhibited solid-like viscoelastic behavior, storage modulus was higher than loss modulus to entire frequency range (G? > G??), which was confirmed by the Cox–Merz experiment that showed that the complex dynamic viscosity was greater than the apparent viscosity in all samples. The gelatinization temperature was mainly influenced by drying technique and ultrasound treatment reduced the amount of energy required to gelatinize the starch.
Dayane Rosalyn Izidoro, Maria-Rita Sierakowski, Charles Windson Isidoro Haminiuk, Clayton Fernandes de Souza, Agnes de Paula Scheer, Journal of Food Engineering 104 (2011) 639–648

B3098 – E, Z and positional-monoenoic phyto-fatty acids influencing membrane fluidity: DSC and NMR experiments

The membrane fluidity of biological tissues is highly influenced by the ?-bond position and isomeric configuration in the long chain of phyto-fatty acids (FAs). Z, E and positional isomeric monoenoic lipids, i.e. the phytomolecules oleic (OA), elaidic (EA), vaccenic acid (TV) and its Z-isomer (CV), have been evaluated for their effects on the fluidity of cellular membranes. To this purpose the Differential Scanning Calorimetry (DSC) and Deuterium Nuclear Magnetic Resonance (2H-NMR), are suitable techniques to understand the supramolecular lamellar structure during the order (gel)-disorder (fluid) transition. It was found that the presence of CV concentration, induces the biomimetic system to reach the first step to fluid phase earlier than the membrane containing OA. DSC showed that the endothermic peak onset of the membrane containing CV occurs at a lower temperature than that of a membrane containing an equal amount of OA. 2H-NMR investigation confirmed the last statement. In fact the study of the main phase transition of the two different systems, revealed that model membrane containing a 3% (w/w) of CV goes in ripple phase, i.e. the first step to the fluid state, at a lower temperature as compared to the membrane of an identical system with OA.
Luigi Filippelli, Cesare Oliviero Rossi, Nicola A. Uccella, Colloids and Surfaces B: Biointerfaces 82 (2011) 13–17

B3097 – Rice Flour – A functional ingredient for premium crabstick

Rice flour possesses functional properties in enhancing texture and whiteness. This study was carried 2 out to evaluate rice flour as a functional ingredient for premium crabstick and develop a commercially viable recipe for premium crabstick. Physicochemical properties of crabstick pastes prepared with 42% surimi, various rice flour concentrations (0, 1, 3, and 5%), and other ingredients were evaluated. The physical properties were measured during refrigerated and frozen storage. Rice flour measured at various concentrations (5% to 40% in water) using differential scanning calorimetry (DSC) demonstrated similar patterns with an endothermic peak at around 63.5oC. During refrigerated storage up to 21 days, the strength of gel increased gradually, while cohesiveness stayed mostly unchanged. At 1% rice flour addition, fracture gel properties during 21 days of refrigerated storage showed optimum results. During frozen storage, water retention ability (WRA) gradually decreased as freeze-thaw (F/T) cycle was extended. However, the reduction was minimized as rice flour concentration increased. Two different crabstick samples (control and 1% rice flour) demonstrated no difference in strength and cohesiveness of gels. Rice flour (1%) can be used to replace various starches as a functional ingredient in premium crabstick.
Sungik Hur, Dong-Soo Kim, Cho Seung-Mock, Jae W. Park, J of Food Science and Biotechnology

B3106 – Structural, physicochemical and rheological characterization of Tacca involucrata starch

Starch was isolated from white and yellow Tacca involucrata tubers and the characteristics studied. The granule morphology was the same for both starches but they differed in granule size distribution: white tacca (6.13–18.12 ?m), yellow tacca (4.19–11.98 ?m). Yellow tacca exhibited an A-type X-ray diffraction pattern but white tacca had a C-type diffraction pattern. White tacca had a slightly higher weight average Mw (2.12 × 107 g/mol) than yellow tacca (1.85 × 107 g/mol). Yellow tacca had lower gelatinization temperature, higher swelling power, higher amylose leaching and higher freeze–thaw stability compared with white tacca. However, the flow characteristics and small deformation mechanical spectra of the starch gels did not differ greatly. The high paste clarity of tacca starches at higher starch concentrations indicates a potential for application in food products like pies and puddings where clarity is desirable.
Louis M. Nwokocha, Chandra Senan, Peter A. Williams, Carbohydrate Polymers 86 (2011) 789– 796

B3105 – Comparative study of physicochemical properties of breadfruit (Artocarpus altilis) and white yam starches

Starch from seedless breadfruit (Artocarpus altilis) was isolated and its granule characteristics, structural, physicochemical and rheological properties compared with white yam starch. Both starches exhibited a B-type diffraction patterns with a crystallinity of 36.2% for breadfruit starch and 37.3% for white yam. The two starches differed in granule size distribution and morphology; while breadfruit starch consisted of small, irregular shaped and aggregated granules (2.3–8.4 ?m), white yam starch granules were large (19.2–30.8 ?m), smooth and uniformly polyhedral. The amylose content and peak gelatinization temperature were different for breadfruit starch (20.0%; 69.3 °C) and white yam starch (22. 8%; 70.2 °C). The gelatinization temperature increased while the enthalpy decreased with increase in sodium chloride concentration for both starches. The starch molecules of breadfruit have a lower weight average Mw (1.72 × 107 g/mol) compared with white yam starch (Mw = 2.32 × 107 g/mol). The swelling power (SP), amylose leaching (AML) at 95 °C, and paste clarity (PC) at 1% (w/w) of breadfruit starch (SP, 39.4 g/g; AML, 5.23%; PC, 2.25%) were lower than those of white yam starch (SP, 49.8 g/g; AML, 10.9%; PC, 12.79%). Its shear viscosity was lower but its ability to withstand viscosity breakdown was higher than white yam starch. The properties of breadfruit starch indicate it would require modification to improve water binding capacity and clarity of the paste, and reduce retrogradation. However, the small granule size of breadfruit starch makes it a candidate for application as a dusting starch.
Louis M. Nwokocha, Peter A. Williams, Carbohydrate Polymers 85 (2011) 294–302

B3104 – Gelatinization of waxy starches under high pressure as influenced by pH and osmolarity: Gelatinization kinetics, final structure and pasting properties

We investigated the influence of pH and osmolarity on the high-pressure-induced gelatinization of waxy corn and waxy rice starches in salt solutions, and the properties of the resulting gels. Gelatinization kinetics, the gel swelling power of starches, their structure and their rheological properties were studied for starch suspensions treated at 500 MPa. Gelatinization took place mostly in the first 15 min of the pressure treatment and both the gelatinization speed and the maximal level of gelatinized starch decreased with increasing osmolarity. pH had a minor influence on gelatinization kinetics differing from one starch to another. The resulting gels appeared as a mix of a gel and starch granules with a higher proportion of native granules with increasing osmolarity. Gel strength and swelling were positively correlated to their proportion of gelatinized starch. Thus, gels with different structures and gelatinization levels can be obtained under pressure depending on pH and osmolarity.
H. Simonin, C. Guyon, M. Orlowska, M. de Lamballerie, A. Le-Bail, LWT - Food Science and Technology 44 (2011) 779-786

B3103 – Comparative effect of thermal treatment on the physicochemical properties of whey and egg white protein foams

The optimization of the functionalities of commercial protein ingredients still constitutes a key objective of the food industry. Our aim was therefore to compare the effect of thermal treatments applied in typical industrial conditions on the foaming properties of whey protein isolate (WPI) and egg white proteins (EWP): EWP was pasteurized in dry state from 1 to 5 days and from 60 °C to 80 °C, while WPI was heat-treated between 80 °C and 100 °C under dynamic conditions using a tubular heat exchanger. Typical protein concentrations of the food industry were also used, 2% (w/v) WPI and 10% (w/v) EWP at pH 7, which provided solutions of similar viscosity. Consequently, WPI exhibited a higher foamability than EWP. For WPI, heat treatment induced a slight decrease of overrun when temperature was above 90 °C, i.e. when aggregation reduced too considerably the amount of monomers that played the key role on foam formation; conversely, it increased foamability for EWP due to the lower aggregation degree resulting from dry heating compared to heat-treated WPI solutions. As expected, thermal treatments improved significantly the stability of WPI and EWP foams, but stability always passed through a maximum as a function of the intensity of heat treatment. In both cases, optimum conditions for foam stability that did not impair foamability corresponded to about 20% soluble protein aggregates. A key discrepancy was finally that the dry heat treatment of EWP provided softer foams, despite more rigid than the WPI-based foams, whereas dynamically heat-treated WPI gave firmer foams than native proteins.
I. Nicorescu, C. Vial, E. Talansier, V. Lechevalier, C. Loisel, D. Della Valle, A. Riaublanc, G. Djelveh, J. Legrand, Food Hydrocolloids 25 (2011) 797-808

B3102 – Thermo- and pH-responsive polyelectrolyte complex membranes from chitosan-g-N-isopropylacrylamide and pectin

Non-stoichiometric polyelectrolyte complex membranes between chitosan-g-N-isopropylacrylamide (PNIPAm) and pectin were prepared and subjected to a thermal treatment by which ionic bonds were converted into amide bonds. Membranes are hydrophilic, with opaque appearance, but vitreous when dry. Swollen membranes undergo a sharp shrinking process with an inflexion point at 33.1 °C. Below LCST, NIPAm chains are hydrated and completely stretched. As temperature increases above LCST, NIPAm chains contract and water is expelled from the polymer matrix, giving rise to the phase transition that is associated to an endothermic peak and is fully thermoreversible. These membranes are not only sensitive to temperature, but also to the pH of the medium whose variation has no influence on LCST. Nevertheless, transition enthalpy decreases when pH increases within studied interval, showing the same trend as equilibrium swelling.
Maricarmen Recillas, Luisa L. Silva, Carlos Peniche, Francisco M. Goycoolea, Marguerite Rinaudo, Julio San Román, Waldo M. Argüelles-Monal, Carbohydrate Polymers 86 (2011) 1336– 1343

B3101 – Effect of molecular weight and chemical structure on thermal and rheological properties of gelling ?/?-hybrid carrageenan solutions

Three ?/?-hybrid carrageenan polysaccharides with distinct molecular mass and content of ?-carrageenan disaccharide units were isolated from Mastocarpus stellatus seaweeds. The viscoelastic and thermal properties of 2 wt% ?/?-hybrid carrageenan solutions with ionic strength tuned by the addition of NaCl salt were studied by means of rheological tests and differential scanning calorimetry (DSC). All solutions form a gel upon cooling. The gel elasticity decreases with the content in ?-carrageenan disaccharide units, and does not correspond to the additive elasticity of a ?- and a ?-carrageenan networks. The highest gel elasticity is obtained with the lowest molecular mass. In 0.1 M NaCl, two gelling processes are evidenced. The first increase in solution viscosity upon cooling coincides with a thermal transition process, which is assigned to a coil-to-helix conformational transition. The transition depends on both molecular mass distribution and chemical structure. The same dependencies are observed for the gel melting behaviour as all rheological and thermal processes determined are shifted to higher temperature with decreased molecular mass or increased content in ?-carrageenan disaccharide units.
Hiléia K.S. Souza, Loic Hilliou, Margarida Bastos, Maria Pilar Gonçalves, Carbohydrate Polymers 85 (2011) 429–438

B3109 – Co-production of butyrate methyl ester and triacetylglycerol from tributyrin and methyl acetate

The simultaneous synthesis of butyric acid methyl ester, the shortest component of the FAME (fatty acid methyl esters) family, and glycerol triacetate (TAG) from glycerol tributyrate (tributyrin) and methyl acetate was studied as a function of several reaction parameters, such as type of catalyst, temperature and products distribution. The reaction is an interesterification, a multistep consecutive ester interchange catalyzed by either acid or base catalyst. Under optimized conditions, a complete tributyrin conversion and an almost quantitative butyric acid methyl ester accumulation were achieved. The other reaction product, TAG, formed by the complete acetylation of the glycerol moiety, reached almost 70% yield, whereas the mono- and di-acetylated intermediates accumulated in the order of 5–8% and 24–27%, respectively. Similar final conversions and products yields were obtained with either acid or base homogeneous catalysts, suggesting that the final products mixture did not depend on the type of catalysis but might be limited by equilibrium conditions. In spite of similar final yields, base catalysis needed shorter reaction times (minutes instead of hours) and lower temperature (60 °C instead of 130 °C) with respect to the best acid catalyst. On the other hand, unlike heterogeneous basic catalysts, which showed low activity, a heterogeneous acid catalyst almost as active as the homogenous counterpart was found.
Ezio Battistel, Chiara Calaprice, Enrico Gualdi, Elena Rebesco, Elisabetta Maria Usai, Applied Catalysis A: General 394 (2011) 149–157

B3108 – Effect of pulsed electric field and thermal treatment on the physicochemical and functional properties of whey protein isolate

The effect of pulsed electric field (PEF) compared with thermal treatment on physicochemical properties (protein aggregation, surface hydrophobicity, contents of exposed and total sulphydryl groups, and thermal stability), and functional (emulsification and gelation) properties of whey protein isolate (WPI) was determined. Within the experimental conditions tested, PEF treatment did not affect any of the physicochemical or emulsification properties of WPI. However, the heat-induced gel strength of WPI decreased from 461 Pa to 139 and 67 Pa after PEF treatment at 30 kV cm?1 for 19.2 and 211 ?s, respectively, and the corresponding gelation times increased from 40.8 min to 43.2 and 47.9 min. This study indicates that the effect of PEF on the gelation properties of WPI may be beneficial in applications where whey protein precipitation and gelation are not desirable, such as during concentration of whey protein preparations and prior to spray drying.
Qian Sui, Hubert Roginski, Roderick P.W. Williams, Cornelis Versteeg, Jason Wan, International Dairy Journal 21 (2011) 206-213

B3107 – Structure and properties of Treculia africana, (Decne) seed starch

Starch isolated from seed flours of four Treculia africana (African breadfruit) trees ranged from 36.0 to 41.7% (w/w, flour). Digital microscopy and image particle size analysis showed smooth, small to medium elliptical granules of sizes 3.56–13.60 ?m with over 80% of the granules in the size range of 5.50–9.49 ?m. T. africana starch displayed an A-type X-ray diffraction pattern with crystallinities in the range of 40.21–43.14%. The apparent amylose content ranged from 21.2 to 23.1% while the absolute amylose content was 13.7–21.7%. The gelatinization characteristics, swelling power and amylose leaching, paste clarity, freeze thaw stability and rheological properties were studied. The gelatinization onset temperatures ranged from 71.5 to 75.1 °C, and the peak gelatinization temperatures and endothermic enthalpies were 74.5–78.8 °C and 12.22–13.99 J/g, respectively. Rheological examination of 5% starch paste over the range of shear rate 0.1–1000/s gave shear viscosities of 3.357–8.285 Pa s and rate indices of 0.44–0.53 and the mechanical spectra indicated that the gels were formed with G? > G?? over the frequency range studied. T. africana starch exhibited low level of syneresis after six freeze thaw cycles (32–38%); however, it would require modification to enhance its application in processed foods.
Louis M. Nwokocha, Peter A. Williams, Carbohydrate Polymers 84 (2011) 395–401

B3113 – Electrocaloric and pyroelectric properties of 0.75Pb„Mg1/3Nb2/3…O3–0.25PbTiO3 single crystals

Pyroelectric and electrocaloric characterization has been determined for 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 relaxor based single crystal and ceramic. Differential scanning calorimetry was used for measuring the electrocaloric response for different electric fields in the vicinity of the Curie temperature. For both ceramic and crystals the maximum activity is found to be around the transition temperature. On the other hand hysteresis loops for different temperatures were used to predict the electrocaloric effect with very good qualitative agreements with direct measurements. Pyroelectric coefficient is found to be much larger for ?111? single crystals reaching 1300×10?6?C?m?2?K?1 whereas the ceramic reaches only 750×10?6?C?m?2?K?1. Higher pyroelectric coefficient and lower dielectric permittivity lead to outstanding figures of merits for sensors and energy harvesting, with a gain of 260% for voltage responsivity and more than 500% for energy harvesting. Although having a much larger pyroelectric activity, the electrocaloric effect is about the same for crystals and ceramics—around 0.40?J/g for 2.5?kV/mm electric field step. This result is interpreted by the decrease of the pyroelectric coefficient for high electric field. The electrocaloric activity is in fact limited by the saturation polarization and difference between Curie transition temperature and the working temperature. Those two parameters are very similar for crystals and ceramics. Single crystals are consequently very interesting materials in the framework of energy harvesting and sensor applications whereas no real improvement of performances can be expected for electrocaloric refrigeration devices.
Gael Sebald, Laurence Seveyrat, Daniel Guyomar, Laurent Lebrun, Benoit Guiffard, Sebastien Pruvost, Journal of Applied Physics 100, 124112 2006

B3112 – Thermodynamic investigation of the (LiF + NaF + CaF2 + LaF3) system

In this work a thermodynamic assessment of the (LiF + NaF + CaF2 + LaF3) system is reported. For the thermodynamic modeling of the liquid phase, the classical polynomial model, and the modified quasi-chemical model were used in parallel and compared. The extrapolation to higher order systems was done according to the Toop mathematical formalism. Furthermore, differential-scanning calorimetry data of the ternary (LiF + CaF2 + LaF3), (NaF + CaF2 + LaF3), and the quaternary (LiF + NaF + CaF2 + LaF3) mixtures are presented. Good agreement between the experimental data and the thermodynamic assessment was obtained.
M. Beilmann, O. Beneš, R.J.M. Konings, Th. Fanghänel, J. Chem. Thermodynamics 43 (2011) 1515–1524

B3111 – Palladium catalysts supported on N-functionalized hollow vapor-grown carbon nanofibers: The effect of the basic support and catalyst reduction temperature

The basic N-functionalized vapor-grown carbon nanofibers (N-VGCF) were synthesized by post-treating oxidized VGCFs in gaseous NH3 at high temperature (ammonolysis) prior to Pd addition by sol immobilization. The catalysts were characterized by nitrogen adsorption, hydrogen temperature programmed desorption, adsorption microcalorimetry and by SEM and TEM. Catalytic activity was evaluated in a model reaction, synthesis of (R)-1-phenylethyl acetate starting from hydrogenation of acetophenone to racemic 1-phenylethanol over Pd supported on N-VGCFs, at 70 °C under atmospheric hydrogen pressure in toluene, followed by acylation over an immobilized lipase in the same reaction pot. The main parameters investigated in this work were the role of the basic N-VGCF supports as well as the reduction procedure of the supported Pd catalysts (Pd-N-VGCF). The results revealed that the catalytic activity of the Pd-N-VGCF catalysts was highly dependent on the reduction procedure. The highest desired product yield, 35%, was obtained over a Pd-N-VGCF catalyst when the support was treated at 400 °C with gaseous ammonia prior to Pd addition.
Serap Sahin, Päivi Mäki-Arvela, Jean-Philippe Tessonnier, Alberto Villa, Sylvia Reiche, Sabine Wrabetz, Dangsheng Su, Robert Schlögl, Tapio Salmi, Dmitry Yu. Murzin, Applied Catalysis A: General 408 (2011) 137– 147

B3110 – Cellulose hydrothermal conversion promoted by heterogeneous Brønsted and Lewis acids: Remarkable efficiency of solid Lewis acids to produce lactic acid

Crystalline cellulose treated in hydrothermal conditions (190 °C, 24 h) is partially solubilised, 30%, into water soluble oligosaccharides/polymers with the formation of small amounts of glucose and 5-HMF. In the presence of solid Brønsted catalysts such as Cs2HPW12O40 and HY zeolite, the extent of the cellulose depolymerisation was not changed when no leaching occurred. However, a quite different products distribution was obtained, in favour of further transformations of glucose and HMF in levulinic and formic acids. On the opposite, solid Lewis acids such as tungstated zirconia (ZrW) and tungstated alumina (AlW) exhibited a remarkable promoting effect on the cellulose depolymerisation which was raised up to 45% while an unexpected decrease of the proportion of water soluble oligosaccharides/polymers was observed. Yields of 27 mol% and 18.5 mol% in lactic acid were achieved on AlW and ZrW, respectively. Moreover, these tungsten based Lewis acids exhibited a good stability and recyclability. The efficiency of the solid Lewis acids ZrW and AlW to produce lactic acid directly from crystalline cellulose was explained by a positive synergy between water autoprotolysis responsible of the cellulose depolymerisation into soluble intermediates which are further converted on the solid Lewis catalyst surface.
Flora Chambon, Franck Rataboul, Catherine Pinel, Amandine Cabiac, Emmanuelle Guillon, Nadine Essayem, Applied Catalysis B: Environmental 105 (2011) 171–181

B3116 – Heat capacity and thermodynamic properties of germanium disulfide at temperatures from T = (2 to 1240) K

The heat capacity of polycrystalline germanium disulfide ?-GeS2 has been measured by relaxation calorimetry, adiabatic calorimetry, DSC and heat flux calorimetry from T = (2 to 1240) K. Values of the molar heat capacity, standard molar entropy and standard molar enthalpy are 66.191 J · K?1 · mol?1, 87.935 J · K?1 · mol?1 and 12.642 kJ · mol?1. The temperature of fusion and its enthalpy change are 1116 K and 23 kJ · mol?1, respectively. The thermodynamic functions of ?-GeS2 were calculated over the range (2 to 1240) K
Jirí Málek, Takefumi Mitsuhashi, Naoki Ohashi, Yuki Taniguchi, Hitoshi Kawaji, Tooru Atake, J. Chem. Thermodynamics 43 (2011) 405–409

B3115 – Ferroelectric electrocaloric conversion in 0.75(PbMg1/3Nb2/3O3)–0.25(PbTiO3) ceramics

This paper presents electrocaloric measurements on 0.75(PbMg1/3Nb2/3O3)–0.25(PbTiO3) ceramics. Reversible heat exchanged up to 0.15?J?g?1 with an applied field of 1.35?kV?mm?1 was obtained. The interpretation of this observation is based on direct polarization measurements. Starting from the integration along the electric field of the derivative of the polarization versus temperature, it was possible to predict the heat upon a decrease in electric field for values up to 3?kV?mm?1. However the simulations differ from the experiments and the discrepancy is believed to be due to hysteresis in ferroelectric materials. Finally a practical limit of the use of ferroelectric 0.75(PbMg1/3Nb2/3O3)–0.25(PbTiO3) ceramics is evidenced through electric conductivity appearance when the electrothermal conversion is very high.
Daniel Guyomar, Gael Sebald, Benoit Guiffard, Laurence Seveyrat, J. Phys. D: Appl. Phys. 39 (2006) 4491–4496

B3114 – Electrocaloric properties of high dielectric constant ferroelectric ceramics

In the last two decades, the electrocaloric (EC) effect which is associated to the temperature (?) dependence of the macroscopic polarization P(E, ?) under electric field E has been spasmodically studied in ferroelectric materials in order to find an alternative to the classical refrigeratory devices using freon. Basically, large electrocaloric temperature variation ?T originates from electric field-induced phase transition at the Curie temperature, but temperature changes of the sample are difficult to measure and depend on the experimental conditions. In this paper, the electrocaloric effect has been quantified directly and precisely by measuring the thermal energy exchanged under isothermal conditions using a modified Differential Scanning Calorimetry (DSC) apparatus. The DSC technique allowed to compare the EC properties of high-dielectric-constant (?) ceramics in the vicinity of ferroelectric–paraelectric phase transition. The measurements were also simulated starting from polarization versus electric field hysteresis loops for different temperatures. It is shown excellent agreement between simulations and direct DSC measurements, except in a limited temperature range where the hysteresis of the polarization versus temperature is high.
Gaël Sebald, Sébastien Pruvost, Laurence Seveyrat, Laurent Lebrun, Daniel Guyomar, Benoît Guiffard, Journal of the European Ceramic Society 27 (2007) 4021–4024

B3117 – Thermodynamics of ???? phase transformation and heat capacity measurements in Ti–15 at% Nb alloy

The phase stability of Ti–15 at% Nb alloy has been studied in the temperature range 466–1258 K using inverse drop calorimetry. In the annealed condition, the alloy consists of orthorhombic ??-martensite and bcc ? phases. The calorimetry experiments indicated the occurrence of two phase changes upon heating. They are (i) precipitation of hexagonal ? phase at 582±2 K followed by (ii) ???? in the temperature domain 836–985±2 K. The enthalpy change due to ? formation is small; however, the ???? phase transformation is associated with a measurable enthalpy effect of 57±3 J g?1. Since ???? phase change occurs over a temperature interval, the measured enthalpy in the transformation domain derives from two principal contributions, namely, the matrix contribution coming from untransformed ??-martensite and ? phase mix and another transformational component arising from continuous ???? phase change. Since the fractional extent of ???? transformation varies continuously with temperature the transformation enthalpy also exhibits similar temperature dependence. This aspect is modeled using Kolmogorov–Johnson–Mehl–Avrami formalism for treating the diffusional transformation kinetics. Further, the measured enthalpy variation with temperature has been subjected to standard analytical treatment to obtain a comprehensive thermodynamic description of entire ??+? region.
A. Josephine Prabha, S.Raju, B.Jeyaganesh, Arun Kumar Rai, Madhusmita Behera, M. Vijayalakshmi, G.Paneerselvam, I.Johnson, Physica B406(2011)4200–4209