Cooling of samples

Cooling of samples of crystalline samarium sulfide containing 22 atom% of gadolinium in the lattice to below — 153°C causes a near-explosive rearrangement to a powder form. This was attributed to changes in the lattice constants corresponding to a volume increase of 7.5%. 

Flash cooling of samples, the use of field-emission guns to generate more coherent electron beams, and improved software has radically extended the power of electron microscopy, so that it is now almost routine to provide structural information for viruses to better than 10 A, and sometimes 7 A resolution (Conway et al., 1997). The major strength... 

Sample I, because of quick cooling, did not form a complete double helix. Slow cooling of sample II allowed more complete double-helix formation. 

The presence of a miscibility gap at equilibrium interferes with the requirements for an absolute asymmetric synthesis from racemic (2). On the other hand, fast cooling of samples of racemate from the melt is associated with the formation of a new phase, almost isomorphous to the eutecticum, but with an internal composition of each crystallite being 50(/ ) 50(5 ) (Scheme 5, c). The existence and nature of this phase was confirmed by two independent routes by differential scanning calorimetry (Figures 2 and 4 a) and from product distribution studies. 

Microthermometry Fluid inclusion analysis that involves the heating and cooling of samples to determine the temperature of phase changes. 

The power consumption for heating and cooling of samples can be reduced if the temperatures in the device are kept constant in three different regions and the sample is moved between these three regions. This movement can be operated at the surface of a thermostating chip, for example, by electrostatic manipulation or by surface acoustic waves (SAWs). Therefore fluidic transport paths (hydrophilic areas) are defined lithographically in a hydrophobic environment on a piezoactive substrate like lithium niobate. The excitation of SAWs is realized by microlithographically prepared thin-film electrodes. SAW systems are of particular interest... 

SECTION A SECTION B SECTION C SECTION D SECTION E SECTION F Sample Records Field Handling and Cooling of Samples Freezer Maintenance and Freezer Logs Sample Storage Sample Shipping Calibration of Temperature Recording Instruments... 

Fig. 4.29. Changes of the crystallinity c, the interface area per unit volume Oac and the mean thickness of the amorphous layers da during cooling of samples of linear PE left column) and branched PE right column) as derived from SAXS experiments and complementary density measurements [32], [46]...

Abrupt cooling of samples in the cholesteric mesophase in some cases permits obtaining polymer films in the glassy state which retain a cholesteric structure. 

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