Physicochemical properties and thermal stability of quercetin hydrates in the solid state

2012 ◽  
Vol 539 ◽  
pp. 109-114 ◽  
Author(s):  
G.S. Borghetti ◽  
J.P. Carini ◽  
S.B. Honorato ◽  
A.P. Ayala ◽  
J.C.F. Moreira ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Physicochemical Properties ◽  
Thermal Stability Of

scholarly journals Thermal and long period stability of series of V(V), V(IV) and V(III) complex with Schiff base ligands in solid state

2019 ◽  
Vol 4 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Janusz Szklarzewicz ◽  
Anna Jurowska ◽  
Maciej Hodorowicz ◽  
Ryszard Gryboś
Keyword(s):  
Thermal Stability ◽  
Schiff Base ◽  
Solid State ◽  
Physicochemical Properties ◽  
General Formula ◽  
Oxidation State ◽  
Magnetic Moment ◽  
Tridentate Ligand ◽  
Schiff Base Ligands ◽  
Long Period

The synthesis and physicochemical properties of three new complexes of vanadium at +5, +4 and +3 oxidation state are described and discussed. The octahedral surrounding of vanadium for V(III) complexes of [V(L1)(HL1)] general formula is filled with two ONO tridentate ligand L, for V(IV) one ONO ligand L, oxido ligand and 1,10-phenanthroline (phen) as a co-ligand are presented in complexes of [VO(L2)(phen)]. For V(V) the complexes of [VO2(L1)(solv)] type were formed. As ligands, the H2L Schiff bases were formed in reaction between 5-hydroxysalcylaldehyde and phenylacetic hydrazide (H2L1) and 3,5-dichlorosalicyaldehyde and 4-hydroxybenzhydrazide (L2). The magnetic moment measurements, in 8 year period, show, that V(III) complexes slowly oxidise to V(IV) with preservation of the nonoxido character of the complexes, while V(IV) complexes were found to be stable. The TG and SDTA measurements indicate, that thermal stability depends mainly on the oxidation state of vanadium. The less thermally stable are the V(V) complexes, while V(IV) and V(III) are stable up to ca. 200oC. In solution, at pH 2 (similar to that in human digestion system), again the V(IV) are the most stable, only at pH 7.0 V(III) complexes had higher stability. The most stable, thus best for pharmaceutical use, are V(IV) complexes.

Solid state amorphization reactions in deformed Ni-Zr multilayered composites

1990 ◽  
Vol 5 (3) ◽  
pp. 488-497 ◽  
Author(s):  
G. C. Wong ◽  
W. L. Johnson ◽  
E. J. Cotts
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Amorphous Phase ◽  
Equilibrium Phase ◽  
Solid State Reactions ◽  
Heat Of Mixing ◽  
Scanning Calorimetry ◽  
Multilayered Composites ◽  
State Amorphization ◽  
Thermal Stability Of

The mechanisms of metallic glass formation and competing crystallization processes in mechanically-deformed Ni-Zr multilayered composites have been investigated by means of differential scanning calorimetry and x-ray diffraction. Our investigation of the heat of formation of amorphous NixZr1−x alloys shows a large negative heat of mixing (on the order of 30 kJ/mole) for compositions near Zr55Ni45 with a compositional dependence qualitatively similar to that predicted by mean field theory. We find that the products of solid state reactions in composites of Ni and Zr can be better understood in terms of the equilibrium phase diagram and the thermal stability of liquid quenched metallic glasses. We have determined the composition of the growing amorphous phase at the Zr interface in these Ni-Zr diffusion couples to be 55 ± 4% Zr. We investigated the kinetics of solid state reactions competing with the solid state amorphization reaction and found the value of the activation energy of the initial crystallization and growth of the growing amorphous phase to be 2.0 ± 0.1 eV, establishing an upper limit on the thermal stability of the growing amorphous phase.

Improvement the thermal stability of bluish-cyan emitting phosphor Y2MgAl4SiO12:Eu2+ using substitution cations (Zn, Ca, Sr) for white LEDs

CrystEngComm ◽  
2021 ◽  
Author(s):  
Huifang Yang ◽  
Panlai Li ◽  
Zejun Ye ◽  
Xiaoxue Huo ◽  
Yu Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Solid State Method ◽  
White Leds ◽  
State Method ◽  
Thermal Stability Of

A series of bluish-cyan color adjustable phosphors Y2MgAl4SiO12:xEu2+(YMAS) and Y2(Mg1-y,My)Al4SiO12:Eu2+ (M=Zn, Ca, Sr) were synthesized by the solid-state method. The thermal stability can be improved by modifying cation, especially, the...

A furnace for in situ synchrotron Laue diffraction and its application to studies of solid-state phase transformations

1990 ◽  
Vol 23 (6) ◽  
pp. 545-549 ◽  
Author(s):  
H. L. Bhat ◽  
S. M. Clark ◽  
A. El Korashy ◽  
K. J. Roberts
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Phase Transitions ◽  
Solid State ◽  
Synchrotron Radiation ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Laue Diffraction ◽  
Thermal Stability Of

The design of a new microfurnace for use for Laue diffraction studies of solid-state transformations is described. The furnace operates in the temperature range 298–573 K with a thermal stability of about ± 0.1 K. The potential of the synchrotron-radiation Laue diffraction technique for studies of structural phase transitions is demonstrated. Experimental data on phase transitions in caesium periodate, potassium tetrachlorozincate and pentaerythritol are presented.

The role of glycosylation and domain interactions in the thermal stability of human angiotensin-converting enzyme

2008 ◽  
Vol 389 (9) ◽  
Author(s):  
Hester G. O'Neill ◽  
Pierre Redelinghuys ◽  
Sylva L.U. Schwager ◽  
Edward D. Sturrock
Keyword(s):  
Thermal Stability ◽  
Angiotensin Converting Enzyme ◽  
Physicochemical Properties ◽  
Mammalian Cells ◽  
Insect Cells ◽  
Thermal Stabilization ◽  
Site Directed Mutagenesis ◽  
Converting Enzyme ◽  
Complex Glycans ◽  
Thermal Stability Of

Abstract The N and C domains of somatic angiotensin-converting enzyme (sACE) differ in terms of their substrate specificity, inhibitor profiling, chloride dependency and thermal stability. The C domain is thermally less stable than sACE or the N domain. Since both domains are heavily glycosylated, the effect of glycosylation on their thermal stability was investigated by assessing their catalytic and physicochemical properties. Testis ACE (tACE) expressed in mammalian cells, mammalian cells in the presence of a glucosidase inhibitor and insect cells yielded proteins with altered catalytic and physicochemical properties, indicating that the more complex glycans confer greater thermal stabilization. Furthermore, a decrease in tACE and N-domain N-glycans using site-directed mutagenesis decreased their thermal stability, suggesting that certain N-glycans have an important effect on the protein's thermodynamic properties. Evaluation of the thermal stability of sACE domain swopover and domain duplication mutants, together with sACE expressed in insect cells, showed that the C domain contained in sACE is less dependent on glycosylation for thermal stabilization than a single C domain, indicating that stabilizing interactions between the two domains contribute to the thermal stability of sACE and are decreased in a C-domain-duplicating mutant.

Solid-state NMR characterization of the structure and thermal stability of hybrid organic–inorganic compounds based on a HLaNb2O7 Dion–Jacobson layered perovskite

2016 ◽  
Vol 18 (31) ◽  
pp. 21903-21912 ◽  
Author(s):  
Alice S. Cattaneo ◽  
Chiara Ferrara ◽  
Adriana Mossuto Marculescu ◽  
Francesco Giannici ◽  
Antonino Martorana ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Solid State Nmr ◽  
Inorganic Compounds ◽  
Layered Perovskite ◽  
Nmr Characterization ◽  
Thermal Stability Of

Hybrids obtained via intercalation of alkylamines or propanol show peculiar structure and thermal stability, which are influenced by the nature and the amount of the intercalated chains.

Crystallization Characteristics and Thermal Stability of Fluor-Hydroxyapatite Composites with Zirconia

2012 ◽  
Vol 182-183 ◽  
pp. 122-125
Author(s):  
Li Li Wang ◽  
Xiu Feng Wang ◽  
Cheng Long Yu ◽  
Hong Tao Jiang
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
Low Temperature ◽  
Solid Solutions ◽  
Tricalcium Phosphate ◽  
Solid State Reaction ◽  
Calcium Fluoride ◽  
Raw Materials ◽  
Thermal Stability Of

Hydroxyapatite (HA) was synthesized in presence of 20wt% m-ZrO2by solid state reaction between tricalcium phosphate(TCP) and Ca(OH)2at 1000 °C for 2h. Similarily, Fluorine hydroxyapatite(FA) was synthesized using tricalcium phosphate and calcium fluoride as raw materials at 1000 °Cfor 3h. The as-prepared HA was mixed with 10%,25%,45%,55%,70wt% FA and the mixture was sintered at 1000°C-1400°C for 2h. The main phase and bulk density was measured. The results show that when the relative amount of FA to HA increased, the decomposition of the composite is decreased gradually because of the formation of thermally stable FHA solid solutions. Low temperature would effect the exchange of ionic between FA and HA,while high temperature would impact synthesis of composites, because high temperature would lead to dissolution of HA ,which has to react with FA. Increase the content of HA would be advantage for synthesis FHA-ZrO2composite.

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