scholarly journals A correlation between protein thermostability and resistance to proteolysis

1982 ◽  
Vol 207 (3) ◽  
pp. 641-644 ◽  
Author(s):  
R M Daniel ◽  
D A Cowan ◽  
H W Morgan ◽  
M P Curran
Keyword(s):  
Thermal Stability ◽  
Thermal Instability ◽  
Soluble Proteins ◽  
Protein Thermostability ◽  
General Correlation ◽  
Similar Correlation ◽  
Different Temperatures ◽  
Micro Organisms ◽  
Different Sources ◽  
Beta Galactosidase

The loss of activity due to proteolysis of purified L-asparaginase and beta-galactosidase from different sources correlates with the thermal instability of the enzymes. A similar correlation is found when populations of soluble proteins from micro-organisms grown at different temperatures are compared for proteolytic susceptibility and thermal stability. It is proposed that there is a general correlation between the thermostability of proteins and their resistance to proteolysis.

scholarly journals Effect of Growth Temperature on the Characteristics of CsPbI3-Quantum Dots Doped Perovskite Film

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4439
Author(s):  
Shui-Yang Lien ◽  
Yu-Hao Chen ◽  
Wen-Ray Chen ◽  
Chuan-Hsi Liu ◽  
Chien-Jung Huang
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Growth Temperature ◽  
Electron Mobility ◽  
Surface Defects ◽  
Different Temperatures ◽  
Pb Doping ◽  
Pristine Film

In this study, adding CsPbI3 quantum dots to organic perovskite methylamine lead triiodide (CH3NH3PbI3) to form a doped perovskite film filmed by different temperatures was found to effectively reduce the formation of unsaturated metal Pb. Doping a small amount of CsPbI3 quantum dots could enhance thermal stability and improve surface defects. The electron mobility of the doped film was 2.5 times higher than the pristine film. This was a major breakthrough for inorganic quantum dot doped organic perovskite thin films.

Polyvinyl fibers as outperform candidature in the solid polymer electrolytes

2020 ◽  
pp. 152808372097062
Author(s):  
Muhammad Yameen Solangi ◽  
Umair Aftab ◽  
Muhammad Ishaque ◽  
Aqeel Bhutto ◽  
Ayman Nafady ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Vital Role ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Main Challenge ◽  
Different Temperatures ◽  
Solution Cast

Solid polymer electrolytes (SPEs) are the best choice to replace liquid electrolytes in supercapacitors, fuel cells, solar cells and batteries. The main challenge in this filed is the ionic conductivity and thermal stability of SPEs which is still not up to mark, therefore more investigations are needed to address these issues. In this study, PVA/salt based SPEs was fabricated using both solution cast and electro-spinning methods to probe the effect of different salts such as (NaCl, KCl and KI) and their concentrations on the ionic conductivity. Scanning electron microscopy (SEM) x and Fourier Transform Infra-Red (FTIR) have been employed to study the morphology as well as the different functional groups of SPEs, respectively. It was noted that small addition of NaCl, KCl and KI salts in SPEs dramatically increased the ionic conductivity to 5.95×10−6, 5.31×10−6 and 4.83×10−6 S/cm, respectively. Importantly, the SPEs obtained with NaCl via electro-spinning have higher ionic conductivity (5.95×10−6 S/cm) than their casted SPEs (1.87×10−6 S/cm). Thermal stability was also studied at two different temperatures i.e. 80 °C and 100 °C. The weight loss percentage of electrospun SPEs have zero percent weight loss than the solution based SPEs. The combined results clearly indicated that the nature of salt, concentration and fabrication process play a vital role in the ionic conductivity. Also, the NaCl salt with low molecular weight at low concentrations shows an enhanced ionic conductivity.

Two-terminal vertical thyristor using Schottky contact emitter to improve thermal instability

Nano Futures ◽  
2021 ◽  
Author(s):  
Min-Won Kim ◽  
Ji-Hun Kim ◽  
Jun-Seong Park ◽  
Byoung-Seok Lee ◽  
Sangdong Yoo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Work Function ◽  
Thermal Instability ◽  
Schottky Contact ◽  
Memory Cell ◽  
Cross Point ◽  
Operation Temperature ◽  
Metal Work Function ◽  
Metal Work ◽  
Contact Metal

Abstract In a two-terminal-electrode vertical thyristor, the latch-up and latch-down voltages are decreased when the memory operation temperature of the memory cells increases, resulting in a severe reliability issue (i.e., thermal instability). This study fundamentally solves the thermal instability of a vertical-thyristor by achieving a cross-point memory-cell array using a vertical-thyristor with a structure of vertical n++-emitter, p+-base, n+-base, and p++-emitter. The vertical-thyristor using a Schottky contact metal emitter instead of an n++-Si emitter significantly improves the thermal stability between 293 and 373 K. Particularly, the improvement degree of the thermal stability is increased significantly with the use of the Schottky contact metal work function. Because the thermal instability (i.e., degree of latch-up voltage decrement vs. memory operation temperature) decreases with an increase in the Schottky contact metal work function, the dependency of the forward current density between the Schottky contact metal and p+-Si based on the memory operation temperature reduces with increase in the Schottky contact metal work function. Consequently, a higher Schottky contact metal work function produces a higher degree of improvement in the thermal stability, i.e., W (4.50 eV), Ti (4.33 eV), Ta (4.25 eV), and Al (4.12 eV). Further research on the fabrication process of a Schottky contact metal emitter vertical-thyristor is essential for the fabrication of a 3-D cross-point memory-cell.

STRUCTURE AND THERMAL STABILITY OF THE SULFIDE OVERLAYERS ON CH3CSNH2-PASSIVATED GaAs(100) SURFACES

2001 ◽  
Vol 08 (01n02) ◽  
pp. 19-23 ◽  
Author(s):  
F. Q. XU ◽  
E. D. LU ◽  
H. B. PAN ◽  
C. K. XIE ◽  
P. S. XU ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electron Spectroscopy ◽  
Photoemission Spectroscopy ◽  
Low Energy Electron Diffraction ◽  
Native Oxides ◽  
Sulfur Passivation ◽  
Different Temperatures ◽  
Low Energy Electron ◽  
Synchrotron Radiation Photoemission ◽  
Thermal Stability Of

Chemically sulfur passivation of GaAs(100) by thioacetamide ( CH 3 CSNH 2) has been studied using synchrotron radiation photoemission spectroscopy (SRPES), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). The measurement of SRPES and AES showed that the top layer of native oxides over GaAs(100) was removed and the sulfides of Ga and As were formed after the passivation process. The thermal stability and surface structure have also been studied by annealing the passivated samples at different temperatures. We found that the surface sulfides could be removed gradually; as a result, a clean, ordered and thus Fermi level unpinning surface was finally achieved. The surface restructures with GaAs(100)–S(2×1) and 4×1 LEED patterns were observed on annealing above 260°C and at 550°C respectively.

Relationship Between Thermal Stability and Summer Oxygen Depletion in a Prairie Pothole Lake

1980 ◽  
Vol 37 (9) ◽  
pp. 1433-1438 ◽  
Author(s):  
M. H. Papst ◽  
J. A. Mathias ◽  
J. Barica
Keyword(s):  
Thermal Stability ◽  
Air Temperature ◽  
Algal Biomass ◽  
Thermal Instability ◽  
Oxygen Depletion ◽  
Prairie Pothole ◽  
Night Time ◽  
Algae Blooms ◽  
Principal Factors ◽  
Prairie Lakes

Periods of summer oxygen depletion (summerkill), occurring in shallow prairie lakes, are dependent on the collapse of algae blooms but are not an obligatory result of the collapse. A period of thermal instability following this bloom collapse, or coincidental with it, is a necessary requirement. Wind stress and night-time air temperature are the principal factors determining the degree of thermal stability. These findings explain the speed with which oxygen depletion can occur, that the occurrence of algal biomass collapses without severe oxygen depletion (partial collapses), and the correlation between the occurrence of periods of lake oxygen depletion and changing weather conditions.Key words: lake, summerkill, anoxia, mixing, oxygen depletion, thermal stability, weather, Aphanizomenon

scholarly journals Improved thermal stability of SiCf/SiC ceramic matrix composites fabricated by PIP process

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim
Keyword(s):  
Thermal Stability ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sic Fiber ◽  
Sic Ceramic ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Thermal Deterioration ◽  
Thermal Stability Of

Improvement of the thermal stability of continuous SiC fiber reinforced SiC ceramic matrix composites (SiCf/SiC CMC) by the pre-treatment of SiC fillers and the suppression of oxidation during polymer impregnation and pyrolysis (PIP) process were investigated. Dense SiCf/SiC CMCs were fabricated using the slurry infiltration and PIP process under a purified argon atmosphere. Structure and mechanical properties of the SiCf/SiC CMC heated at different temperatures were evaluated. The flexural strength of the SiCf/SiC CMC decreased only 15.3%after heating at 1400 ?C, which exhibited a clear improvement compared with the literature data (49.5% loss), where severe thermal deterioration of SiCf/SiC composite occurred at high temperatures by the crystallization and decomposition of the precursor-derived ceramic matrix. The thermal stability of the SiCf/SiC CMC fabricated by PIP process was improved by the pre-treatment of SiC fillers for removing oxides and the strict atmosphere control to prevent oxidation.

BIOPROSPECTING FOR CYCLODEXTRIN GLYCOSYLTRANSFERASE PRODUCING BACTERIA

INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (06) ◽  
pp. 44-48
Author(s):  
Y. Rajesh ◽  
◽  
K Narayanan ◽  
V. M. Subrahmanyam ◽  
J. Venkata Rao
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Drug Carrier ◽  
Enzymatic Conversion ◽  
Cyclodextrin Glycosyltransferase ◽  
Bcs Class Ii ◽  
Rf Values ◽  
Micro Organisms ◽  
Layer Chromatography ◽  
Different Sources

Cyclodextrin glycosyltransferase- (CGTase), (EC.2.4.1.19) producing micro-organisms were isolated from different sources of soil (paddy plantation, potato plantation, garden and Malpe beach) from places in and around Udupi, India. A potential isolate MBS 24 was identified as Virgibacillus pantothenticus. This organism was cultivated on modified Horikoshi medium at 130 rpm for 24 h at 32 °C. The maximum production of CGTase enzyme was observed (0.308μmol/ml β-CD units) after 36 h of incubation at 32°C and pH 10.0. CGTase was precipitated using ammonium sulphate at 60% saturation. Cyclodextrin (CD) produced by incubation of CGTase with starch was extracted using toluene and analyzed by thin layer chromatography. Rf values of the solvent extracted CD were similar to the standard α, β and γ CD confirming that all three types of CD’s were formed during enzymatic conversion. These CDs could be used as drug carrier for delivering BCS class II drugs.

One-step purification of a recombinant beta-galactosidase using magnetic cellulose as a support: Rapid immobilization and high thermal stability

2021 ◽  
pp. 126497
Author(s):  
Adriano Gennari ◽  
Renate Simon ◽  
Nathalia Denise de Moura Sperotto ◽  
Cristiano Valim Bizarro ◽  
Luiz Augusto Basso ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Thermal Stability ◽  
One Step ◽  
Beta Galactosidase

Thermal Stability of Mechanical Properties of Copper after Equal-Channel Angular Pressing

2008 ◽  
Vol 584-586 ◽  
pp. 960-965 ◽  
Author(s):  
Tamara Kravchenko ◽  
Alexander Korshunov ◽  
Natalia Zhdanova ◽  
Lev Polyakov ◽  
Irina Kaganova
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Chemical Composition ◽  
Yield Strength ◽  
Equal Channel Angular Pressing ◽  
Angular Pressing ◽  
Different Temperatures ◽  
Thermal Stability Of

Annealed oxygen-free and tough-pitch copper samples have been processed by equalchannel angular pressing (ECAP) by route BC. The samples included 8 x 8 mm section pieces and a 40 mm diameter bar. Thermal stability was assessed based on the changes in the standard mechanical properties (conventional yield strength, tensile strength, elongation, proportional elongation and contraction) after annealing at different temperatures for 1 hour. Thermal stability of the same grade of material has been found to be different for different batches and to depend on the structural conditions of deformed material. The zone of thermal stability for copper of the two grades of interest does not depend on the material’s chemical composition.

Thermal Stability of Ti/Pt/Au Non-Alloyed Ohmic Contacts on InN

1994 ◽  
Vol 337 ◽  
Author(s):  
F. Ren ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
P. W. Wisk
Keyword(s):  
Thermal Stability ◽  
Doping Level ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Contact Resistivity ◽  
High Doping Level ◽  
Transmission Line Method ◽  
Different Temperatures ◽  
Contact Resistivities ◽  
Thermal Stability Of

ABSTRACTExtremely low contact resistance of non-alloyed Ti/Pt/Au metallization on n-type InN is demonstrated. The contacts were annealed at different temperatures up to 420 °C to investigate their thermal stability. A low contact resistivity of 1.8 x 10-7 ohm-cm2 was measured at room temperature using the transmission line method. This was due to the extremely high doping level (5 x 1020 cm-3) in the InN. After 300 °C annealing, the contact resistivity increased to 2.4 x 10-7 ohm-cm2- For 360 °C annealing, the contact morphology showed some degradation, but the contact resistivity was almost the same as at 300 °C. There was serious degradation of the contacts after 420 °C annealing. The morphology became very rough, and the contact and sheet resistances increased by factors of 3-5 times. This degradation is believed due to the decomposition of the InN film. The contact resistivities between n-type epitaxial GaAs and InN were also investigated, and showed values around 10-4 ohm-cm2.

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