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Heating Stage (heating + stage)
Selected AbstractsA heating stage up to 1173,K for X-ray diffraction studies in the whole orientation spaceJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2003R. Resel A multi-purpose heating attachment designed primarily for X-ray four-circle diffractometers but applicable also for classical powder diffraction is presented. When working in reflection geometry, the air-cooled heating stage allows diffraction studies to be performed on plate-like samples up to 1173,K in the whole orientation space. This paper gives a detailed description of the assembly and important technical specifications for the performance of experiments. The heating characteristics of the heating stage, the displacement of the sample from the goniometer centre as a result of thermal expansion and the influence of the protecting dome on the diffraction experiment are presented. The simple technical construction, the low weight, the small size and good heating performance make this equipment a general purpose heating attachment for X-ray diffraction experiments in reflection geometry. [source] Influence of heating conditions and starch on the storage modulus of Russet Burbank and Yukon Gold potatoesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2001Renan Bu-Contreras Abstract The storage modulus of Russet Burbank (RB) and Yukon Gold (YG) potato discs (13.3,mm,× 4.5,mm) was measured continuously during heating in water at temperatures ranging from 40 to 80,°C for 120,min using a dynamic mechanical analyser with a heating stage. The starch content of YG potatoes was higher than that of RB potatoes, but the raw starch granule size distribution of both varieties was similar. RB samples had the highest storage modulus values (25% higher than raw tissue) when heated in 60,°C water for 35,min. Image analysis revealed that the perimeters of starch granules in the potato samples increased by about 50% during heating for 30,min at 60,°C. Heating temperature and time and starch content influenced the storage modulus. © 2001 Society of Chemical Industry [source] Effects of Liquid Holdup in Condensers on the Start-Up of Reactive Distillation ColumnsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 11 2006H.-X. Wu Abstract Compared with start-ups in conventional distillation columns, those in reactive distillation (RD) columns are much more time and energy consuming, and generate a large amount of by-products which are not easy to deal with together. For several years, researchers have been trying out different methods to shorten the time required to lower the cost of the start-up. In this work, a rigorous dynamic model in the ChemCAD simulator is applied to model the start-up process for the esterification of ethyl acetate in a reactive distillation column. In the model, two sets of equations are employed: one for the fill-up and heating stage and the other for the equilibration process which follows. In the fill-up and heating stage, fluctuation curves of the reboiler temperatures with respect to time which are similar to those for conventional distillation columns are observed, while in the equilibration process it is found that the increase of the liquid holdup volume in the condenser reduces the time required to reach steady state for the reactive column and decreases the liquid holdup volume in the reboiler at the equilibrium state. This shows that the liquid holdup volume in the condenser has an important effect on the start-up of reactive distillation columns. [source] Synthesis of Schiff Base-type Liquid Crystalline Crown Ethers Containing Dibenzo-18-Crown-6 UnitCHINESE JOURNAL OF CHEMISTRY, Issue 4 2004Shu-Yuan Zhang Abstract The synthesis and characterization of novel Schiff base liquid crystalline crown ethers prepared from the intermediates 4-(4,-alkoxylbiphenyl-4-carbonyl) benzaldehyde, cis- and trans -4,4,-diaminodibenzo-18-crown-6 are described. The structure of these compounds have been well characterized by elemental analysis, IR, 1H NMR and MS spectroscopy. The liquid-crystalline behavior of these compounds was also investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) with a heating stage and polarimetric analysis. [source] | ||||||||||