Structural Changes during Thermally Induced Phase Transitions Observed for Uniaxially Oriented δ Form of Syndiotactic Polystyrene

2007 ◽  
Vol 40 (17) ◽  
pp. 6291-6295 ◽  
Author(s):  
E. Bhoje Gowd ◽  
Naoya Shibayama ◽  
Kohji Tashiro
Keyword(s):  
Phase Transitions ◽  
Structural Changes ◽  
Syndiotactic Polystyrene ◽  
Thermally Induced

scholarly journals Investigation of thermally induced phase transitions in uranium perovskites

2014 ◽  
Vol 70 (a1) ◽  
pp. C71-C71
Author(s):  
Emily Reynolds ◽  
Brendan Kennedy
Keyword(s):  
Phase Transitions ◽  
Structural Changes ◽  
Mode Analysis ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
System A ◽  
Metastable Structures ◽  
Limited Temperature ◽  
Comprehensive Knowledge

The physical properties of inorganic solids are intimately related to their crystal structures and there is increasing awareness of the potential importance of metastable structures that exist over a limited temperature and/or pressure range. For the renaissance of nuclear energy to continue it is vital to improve the efficiency and safety of the nuclear fuel process. In order to do this, a comprehensive knowledge of the fundamental chemical, structural, and thermodynamic properties of uranium compounds is required. Compounds of the type A2BUO6 (A = Ba, Sr; B = Ba, Sr, Ca) have been prepared and characterised using neutron and X-Ray diffraction techniques as well as X-ray absorption spectroscopy. For the first time the high temperature behaviour of these complex oxides has been investigated, and as illustrated by Ba2SrUO6, heating such oxides can induce a sequence of phase transitions with the structure of Ba2SrUO6 changing from monoclinic in P21/n at room temperature to cubic in Fm-3m above 1200 K. [1] The compounds Ba2CaUO6 and BaSrCaUO6 were also found to undergo a series of thermally induced phase transitions from the P21/n monoclinic structure. In order to elucidate the structural changes involved in each system, a combination of diffraction techniques was required. We also utilised symmetry-mode analysis in which the structures are refined in terms of the fundamental tilting modes. This elegant way of tracking phase transitions provided vital insight when comparing and contrasting the thermal behaviour of these complex uranium oxides.

Thermally-Induced Phase Transitions in the Uniaxially-Oriented δ Form of Syndiotactic Polystyrene

2006 ◽  
Vol 242 (1) ◽  
pp. 257-261 ◽  
Author(s):  
E. Bhoje Gowd ◽  
Naoya Shibayama ◽  
Kohji Tashiro
Keyword(s):  
Phase Transitions ◽  
Syndiotactic Polystyrene ◽  
Thermally Induced

scholarly journals Temperature-dependent nanomechanics and topography of bacteriophage T7

2018 ◽  
Author(s):  
Zsuzsanna Vörös ◽  
Gabriella Csík ◽  
Levente Herényi ◽  
Miklós Kellermayer
Keyword(s):  
Structural Changes ◽  
Mechanical Stability ◽  
Genetic Material ◽  
Heat Inactivation ◽  
Infectious Agents ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Partial Denaturation ◽  
Induced Changes ◽  
T7 Bacteriophage

AbstractViruses are nanoscale infectious agents which may be inactivated by heat treatment. Although heat inactivation is thought to be caused by the release of genetic material from the capsid, the thermally-induced structural changes in viruses are little known. Here we measured the heat-induced changes in the properties of T7 bacteriophage particles exposed to two-stage (65 °C and 80 °C) thermal effect by using AFM-based nanomechanical and topographical measurements. We found that exposure to 65 °C caused the release of genomic DNA due to the loss of the capsid tail which leads to a destabilization of the T7 particles. Further heating to 80 °C surprisingly led to an increase in mechanical stability due to partial denaturation of the capsomeric proteins kept within the global capsid arrangement.

LDA calculations of the pressure induced structural changes and phase transitions in PbTiO3

1995 ◽  
Vol 164 (1) ◽  
pp. 279-289 ◽  
Author(s):  
O. N. Mryasov ◽  
D. L. Novikov ◽  
A. J. Freeman
Keyword(s):  
Phase Transitions ◽  
Structural Changes

Thermally-induced structural changes and optical properties degradation of fiber-loaded aerogel composites under thermal exposures

2020 ◽  
Vol 110 ◽  
pp. 103470
Author(s):  
Shuyuan Zhao ◽  
Jianglong Dong ◽  
Christian Monte ◽  
Xinyang Sun ◽  
Wenjiao Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Changes ◽  
Thermally Induced
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