The thermal dehydration of naturally occurring Ca-montmorillonite has been studied by in situ X-ray diffraction at temperatures between 60 1208C. The time-temperature-dependence of the position of the basal (001) reflection reveals that interlayer water loss on isothermal dehydration occurs in two stages. After an initial rapid decrease in interlayer spacing (on shock heating to an isothermal soak temperature) the reaction proceeds towards equilibrium more slowly. Furthermore, the width of the (001) reflection changes with time, reflecting transformation-dependent changes in homogeneity perpendicular to (001) with a maximum in peak width at the point where the rate of the reaction appears to change. This suggests that, as the interlayer spacing collapses, a local change is induced in the structure, affecting the means of movement of the water from the interlayer.

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The dehydroxylation of Ca-, K-, Mg- and Na-saturated Wyoming montmorillonite has been studied by thermogravimetry (TG), infrared (IR) spectroscopy and X-ray diffraction (XRD). Samples saturated with either Ca2+ or Mg2+ show a predominantly diffusion-controlled reaction step, whereas Wyoming montmorillonite with Na+ and K+ in the interlayer exhibit control closer to first order. The activation energy of dehydroxylation is not significantly correlated to the type of interlayer cation present, in turn demonstrating that the role of vacancy location in the octahedral sheet is more significant a control on dehydroxylation.

Physiological state profoundly influences the expression of the behaviour of individuals and can affect social interactions between animals. How physiological state influences food sharing and social behaviour in social insects is poorly understood. Here, we examined the social interactions and food sharing behaviour of honeybees with the aim of developing the honeybee as a model for understanding how an individual's state influences its social interactions. The state of individual honeybees was manipulated by either starving donor bees or feeding them sucrose or low doses of ethanol to examine how a change in hunger or inebriation state affected the social behaviours exhibited by two closely-related nestmates. Using a lab-based assay for measuring individual motor behaviour and social behaviour, we found that behaviours such as antennation, willingness to engage in trophallaxis, and mandible opening were affected by both hunger and ethanol intoxication. Inebriated bees were more likely to exhibit mandible opening, which may represent a form of aggression, than bees fed sucrose alone. However, intoxicated bees were as willing to engage in trophallaxis as the sucrose-fed bees. The effects of ethanol on social behaviors were dose-dependent, with higher doses of ethanol producing larger effects on behaviour. Hungry donor bees, on the other hand, were more likely to engage in begging for food and less likely to antennate and to display mandible opening. We also found that when nestmates received food from donors previously fed ethanol, they began to display evidence of inebriation, indicating that ethanol can be retained in the crop for several hours and that it can be transferred between honeybee nestmates during trophallaxis.

The fom1ation of ceramic matetials from precursor sol-gels and zeolitic systems has been investigated by combined QuEX.A.FS!XRD and SAXS/WAXS, measured in-situ. under isothermal or ramping temperature regimes upto 1200°C. A new high temperature environmental cell, with the advantage of measuring both fluorescence and transmission EXAFS data. and having a wide ( 1 oo -70° 28) angular range for the XRD, has been designed in order to improve temperature uniformity at 1000°C and san1ple support for fragile specimens, a similar fumace being used for the SAXS/Wi0CS measurements. A vmiety of matetials have been studied. including PLZT. LSCF's, cordietite glasses. phase transitions in oxides. nanocrystalline materials. m1d zeolites as precursors to ceramics.The crystallisation ofPLZT (lead lanthanum zirconate titm1ate) ti·om an alkoxide sol-gel shows a three stage evolution. an an1o1-phous precursor. a pyrochlore!flu01ite intem1ediate and the final perovskite phase. From the in-situ measurements it is possible to obtain quantitative kinetic information.· the activation energy for crystallisation depending on the La concentration.The combined QuEXAFS!XRD and Sl\..~'(S/WAXS studies on the collapse of zeolites A andY has enabled the dilute crystallography of Cd-exchanged sites, followed by Cd K-edge EXAFS. to be directly related to the alteting mesostructure defined by the SAXS, on structural change from microporous crystalline to amorphous alumino-silicate as the glass transition is approached, by compatison between the WAXS diffraction profiles. Within the temperature regime investigated zeolite A is found to recrystallise into carnegieite and nepheline. whereas zeolite Y tends to remain an101-phous. Unlike the Pb-doped 2223 ((Bi.Pb):Sr:Ca:Cu) phase, relatively little data has been reported on the chm·acterization and applications of the Pb-free 2223 phase. This is probably due to the difficulty of prepming high purity materiaL We have successfully prepm·ed a mostly single phase 2223 mate1iaL Since melting information is important for processing, the goal of this paper is to use the in-situ high temperature x-ray technique (in combination with the them1al differential analysis (DTA) and quantitative SEM/EDS) to investigate the melting sequence of the 2223 phase. MS10.09.06 HIGH TEMPERATURE X-RAY DIFFRI\.C-TION STUDY OF THE MELTING SEQlJENCE OF THEIt was found that the melting sequence of the 2223 phase is similar to the 2212 phase in that the ptimm-y crystals me calcium strontium cuprates and calcium strontium oxides. In the Ag-free material, at least two phases were observed during the melting process. At m·ound 890°, the (Ca,Sr) 2 Cu03 appemed and at around 950°C, the (Ca,Sr)O phase was formed. When Ag powder was well mixed with the the sample, the melting temperature of the 2223 phase was lowered by about 20°C and at least 3 aU;:alineearth phases were observed during melting. At around 870°C (Ca.Sr)Cu02 was observed first followed by the appearance of (Ca,Sr)2Cu0 3 at"' 890°C and (Ca,Sr)O at about 950°C. The dehydrati...