Measurement of the enthalpy of phase transition for iron chevrel phase sulphide in the temperature range from 300 to 500 K

1992 ◽  
Vol 38 (8) ◽  
pp. 1939-1945
Author(s):  
H. Honda ◽  
A. Oshima ◽  
H. Hinode ◽  
M. Wakihara
Keyword(s):  
Phase Transition ◽  
Temperature Range ◽  
Chevrel Phase ◽  
Enthalpy Of Phase Transition

Measurements of enthalpies of phase transition for chromium Chevrel-phase sulphides in the temperature range from 400 to 900 K

1991 ◽  
Vol 191 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Akihiro Oshima ◽  
Eitaroh Ike ◽  
Hirofumi Hinode ◽  
Masataka Wakihara
Keyword(s):  
Phase Transition ◽  
Temperature Range ◽  
Chevrel Phase

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

scholarly journals FTIR Spectra of n-Octanol in Liquid and Solid States

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
A. Vasileva ◽  
P. Golub ◽  
I. Doroshenko ◽  
V. Pogorelov ◽  
V. Sablinskas ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Phase ◽  
Temperature Dependence ◽  
Ftir Spectra ◽  
Ftir Spectrum ◽  
Structure Transformation ◽  
Temperature Range ◽  
Solid States

The investigation of the temperature dependence of FTIR spectrum of n-octanol in the temperature range from −150°C to 50°C is presented. The observed changes in the registered spectra during gradual heating of the sample were analysed. The structure transformation at the phase transition from solid to liquid phase is detected.

scholarly journals Parameters Expediting the Thermal Conversion of Ba-Exchanged Zeolite A to Monoclinic Celsian

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
A. Marocco ◽  
M. Pansini ◽  
G. Dell'Agli ◽  
S. Esposito
Keyword(s):  
Phase Transition ◽  
Amorphous Phase ◽  
Room Temperature ◽  
Thermal Conversion ◽  
Zeolite A ◽  
Thermal Transformations ◽  
Final Phase ◽  
Temperature Range ◽  
Thermally Treated

Four samples of Ba-exchanged zeolite A, bearing small residual amounts of Na (0.27, 0.43, 0.58, and 0.74 meq/g), were thermally treated in the temperature range 200–1500∘C for times up to 28 hours. The same samples were pressed at 30 and 60 MPa to form cylindrical pellets which were thermally treated at 1300∘C for 5 hours. All materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite → amorphous phase → hexacelsian → monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian → monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A for transformation into monoclinic celsian is assessed to be between 0.27 and 0.43 meq/g.

Preparation of RHA-Paraffin Phase Change Materials

2011 ◽  
Vol 399-401 ◽  
pp. 1156-1159
Author(s):  
Jun Wang ◽  
Bao Guo Ma ◽  
Jian Liang Zhang ◽  
Wen Yang
Keyword(s):  
Phase Transition ◽  
Phase Change ◽  
Phase Change Material ◽  
Rice Husk ◽  
Absorption Rate ◽  
Phase Change Materials ◽  
Rice Husk Ash ◽  
Dsc Analysis ◽  
Change Material ◽  
Enthalpy Of Phase Transition

In this paper, a kind of RHA-paraffin phase change material was prepared, and the SEM was used for observing its internal morphologies, DSC analysis was carried out for detecting its temperature and enthalpy of phase transition. The results showed that rice husk ash have a greater absorption rate for paraffin; a large number of pores of the RHA were filled by paraffin in the RHA-paraffin phase change material, and the absorption rate can reach 53.5%.

A conformational polymorphic transition in the high-temperature ∊-form of chlorpropamide on cooling: a new ∊′-form

2009 ◽  
Vol 65 (6) ◽  
pp. 770-781 ◽  
Author(s):  
Tatiana N. Drebushchak ◽  
Yury A. Chesalov ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Structural Changes ◽  
Molecular Conformation ◽  
Polymorphic Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Temperature Range ◽  
Two Phases

Structural changes in the high-temperature ∊-polymorph of chlorpropamide, 4-chloro-N-(propylaminocarbonyl)benzenesulfonamide, C10H13ClN2O3S, on cooling down to 100 K and on reverse heating were followed by single-crystal X-ray diffraction. At temperatures below 200 K the phase transition into a new polymorph (termed the ∊′-form) has been observed for the first time. The polymorphic transition preserves the space group Pna21, is reversible and is accompanied by discontinuous changes in the cell volume and parameters, resulting from changes in molecular conformation. As shown by IR spectroscopy and X-ray powder diffraction, the phase transition in a powder sample is inhomogeneous throughout the bulk, and the two phases co-exist in a wide temperature range. The cell parameters and the molecular conformation in the new polymorph are close to those in the previously known α-polymorph, but the packing of the z-shaped molecular ribbons linked by hydrogen bonds inherits that of the ∊-form and is different from the packing in the α-polymorph. A structural study of the α-polymorph in the same temperature range has revealed no phase transitions.

On the Thermal Behaviour of Some Alkali Branched Alkanoates. Note I

1978 ◽  
Vol 33 (2) ◽  
pp. 240-242 ◽  
Author(s):  
P. Ferloni ◽  
M. Sanesi ◽  
P. L. Tonelli ◽  
P. Franzosini
Keyword(s):  
Phase Transition ◽  
Thermal Behaviour ◽  
Differential Scanning Calorimetric ◽  
Transition Temperatures ◽  
Calorimetric Investigation ◽  
Temperature Range ◽  
Heat Effects ◽  
Phase Transition Temperatures ◽  
Sodium And Potassium

Lithium, sodium and potassium isobutyrates, isovalerates and isocaproates were submitted to a differential scanning calorimetric investigation in the temperature range between 320 K and the isotropic melt region. The collected phase transition temperatures and heat effects are compared to those of the corresponding linear isomers. In particular the occurrence of mesomorphic liquids and the width of their existence fields is discussed.

Stability field and phase transition pathways of hydrous ferric sulfates in the temperature range 50°C to 5°C: Implication for martian ferric sulfates

Icarus ◽  
2012 ◽  
Vol 218 (1) ◽  
pp. 622-643 ◽  
Author(s):  
Alian Wang ◽  
Zongcheng Ling ◽  
John J. Freeman ◽  
Weigang Kong
Keyword(s):  
Phase Transition ◽  
Stability Field ◽  
Temperature Range ◽  
Transition Pathways
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