Maintenance Properties of Enzyme Molecule Stereostructure at High Temperature by Adsorption on Organo-Modified Magnetic Nanoparticle Layer Template

2019 ◽  
Vol 92 (10) ◽  
pp. 1662-1671 ◽  
Author(s):  
Takeru Yunoki ◽  
Yusuke Kimura ◽  
Atsuhiro Fujimori
1996 ◽  
Vol 74 (10) ◽  
pp. 1665-1670 ◽  
Author(s):  
N. T. Bakardjieva ◽  
N. Christova ◽  
K. Christov

Incubation of peroxidase from Mnium sp. and Polypodium vulgare with calcium or zinc ions caused an activation or inhibition. The enzyme was thermostabilized. The pronounced effect of calcium is interpreted as the result of its established structural role in the enzyme molecule and the hypothesis that calcium maintains the peptide bonds around the active site. The individual peroxidase isoenzymes reacted differently to metal ions added and to increased temperatures. These results are important for characterization of metabolic response to environmental stress and can be used in biological monitoring. Keywords: peroxidase, enzyme thermosensitivity, mosses, ferns, calcium, zinc.


2003 ◽  
Vol 93 (10) ◽  
pp. 7571-7573 ◽  
Author(s):  
Y. Sui ◽  
L. Yue ◽  
R. Skomski ◽  
X. Z. Li ◽  
J. Zhou ◽  
...  

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2669-2674
Author(s):  
B. Dodrill ◽  
P. Ohodnicki ◽  
M. McHenry ◽  
A. Leary

AbstractFirst-order-reversal-curves (FORCs) are an elegant, nondestructive tool for characterizing the magnetic properties of materials comprising fine (micron- or nano-scale) magnetic particles. FORC measurements and analysis have long been the standard protocol used by geophysicists and earth and planetary scientists investigating the magnetic properties of rocks, soils, and sediments. FORC can distinguish between single-domain, multi-domain, and pseudo single-domain behavior, and it can distinguish between different magnetic mineral species [1]. More recently, FORC has been applied to a wider array of magnetic material systems because it yields information regarding magnetic interactions and coercivity distributions that cannot be obtained from major hysteresis loop measurements alone. In this paper, we will discuss this technique and present high-temperature FORC results for two magnetic nanoparticle materials: CoFe nanoparticles dispersed in a SiO2 matrix, and FeCo-based nanocrystalline amorphous/nanocomposites.


Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.


Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


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