Physical and chemical nature of cemented carbides

1979 ◽  
Vol 24 (1) ◽  
pp. 149-173 ◽  
Author(s):  
H. E. Exner
Keyword(s):  
Chemical Nature ◽  
Cemented Carbides ◽  
Physical And Chemical

scholarly journals Real Nano “Light Vaccine” Will Benefit to COVID-19 Pandemic Control

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jianshe Yang
Keyword(s):  
Near Infrared ◽  
Chemical Nature ◽  
Strong Acid ◽  
Alveolar Type ◽  
Type Ii ◽  
Nir Light ◽  
Physical Absorption ◽  
Acid And Base ◽  
And Control ◽  
Physical And Chemical

AbstractThis highlight presents a recent technique of “Light Vaccine” for COVID-19 pandemic control. Though this technique has the germicidal advantage to SARS-CoV-2, its shortcomings will limit the wide and in-depth application. We make a perspective of real nano light vaccine, which will play an important role in the prevention and control of COVID-19. Briefly, This flow chart described the MWCNT was fabricated with strong acid and base conditional mixture in order to achieve the p-WCNT (chemical process); then modified with RNA layse and receptor binding domain (RBD) by covalent conjugation and physical absorption to get f-WCNT (functionalization); thereafter, f-WCNT was used in the multi-cell culture system interacting with SARS-CoV-2 to identify the special affinity of f-WCNT to ACE2 labeled alveolar type II cells and the inhibition capacity to SARS-CoV-2. This design, is different from the so called “light vaccine”, has the real function to against SARS-CoV-2 by local cellular temperature-rising through photothermal conversion under the near infrared (NIR) light irradiation, according to the physical and chemical nature of carbon nanotubes, and initiates the immune response consequently.

scholarly journals In-Depth Understanding of Fatigue Micromechanisms in Cemented Carbides: Implications for Optimal Microstructural Tailoring

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 924 ◽  
Author(s):  
Llanes
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Chemical Nature ◽  
Advanced Characterization ◽  
Cemented Carbides ◽  
Effective Implementation ◽  
Metal Materials ◽  
Fatigue Microstructure ◽  
Fatigue Sensitivity

The fatigue mechanics and mechanisms of cemented carbides (composites usually referred to as hardmetals) are reviewed. The influence of microstructure on strength lessening and subcritical crack growth for these ceramic-metal materials when subjected to cyclic loads are highlighted. The simultaneous role of the ductile metallic binder as a toughening and fatigue-susceptible agent for hardmetals results in a tradeoff between properties measured under monotonic and cyclic loading: fracture strength and toughness on one hand, as compared to fatigue strength and crack growth resistance on the other one. Toughness/fatigue–microstructure correlations are analyzed and rationalized on the basis of specific crack–microstructure interactions, documented by the effective implementation of advanced characterization techniques. As a result, it is concluded that the fatigue sensitivity of cemented carbides may be reduced if either toughening mechanisms beyond ductile ligament bridging, such as crack deflection, are operative, or strain localization within the binder is suppressed. In this regard, grades exhibiting metallic binders of a complex chemical nature and/or distinct microstructural assemblages are proposed as options for effective microstructural tailoring of these materials.

scholarly journals Glycoprotein of the wall of sycamore tissue-culture cells

1971 ◽  
Vol 125 (4) ◽  
pp. 953-961 ◽  
Author(s):  
M. F. Heath ◽  
D. H. Northcote
Keyword(s):  
Cell Walls ◽  
Chemical Nature ◽  
Gel Filtration ◽  
Degree Of Polymerization ◽  
Separation Procedure ◽  
Peptide Bonds ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Physical And Chemical ◽  
Soluble Material

1. A glycoprotein containing a large amount of hydroxyproline is present in the cell walls of sycamore callus cells. This protein is insoluble and remained in the α-cellulose when a mild separation procedure was used to obtain the polysaccharide fractions of the wall. The glycoprotein contained a high proportion of arabinose and galactose. 2. Soluble glycopeptides were prepared from the α-cellulose fraction when peptide bonds were broken by hydrazinolysis. The soluble material was fractionated by gel filtration and one glycopeptide was further purified by electrophoresis; it had a composition of 10% hydroxyproline, 35% arabinose and 55% galactose, and each hydroxyproline residue carried a glycosyl radical so that the oligosaccharides on the glycopeptide had an average degree of polymerization of 9. 3. The extraction of the glycopeptides was achieved without cleavage of glycosyl bonds, so that the glycoprotein cannot act as a covalent cross-link between the major polysaccharides of the wall. 4. The wall protein approximates in conformation to polyhydroxyproline and therefore it probably has similar physicochemical properties to polyhydroxyproline. This is discussed in relation to the function of the glycoprotein and its effect on the physical and chemical nature of the wall.

scholarly journals Direct and Indirect Influence of Parental Bedrock on Streambed Microbial Community Structure in Forested Streams

2011 ◽  
Vol 77 (21) ◽  
pp. 7681-7688 ◽  
Author(s):  
Jennifer J. Mosher ◽  
Robert H. Findlay
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Chemical Nature ◽  
Stream Water ◽  
Phospholipid Fatty Acid ◽  
Fatty Acid Analysis ◽  
Chemical Parameters ◽  
Physical And Chemical ◽  
Benthic Microbial Communities

ABSTRACTA correlative study was performed to determine if variation in streambed microbial community structure in low-order forested streams can be directly or indirectly linked to the chemical nature of the parental bedrock of the environments through which the streams flow. Total microbial and photosynthetic biomass (phospholipid phosphate [PLP] and chlorophylla), community structure (phospholipid fatty acid analysis), and physical and chemical parameters were measured in six streams, three located in sandstone and three in limestone regions of the Bankhead National Forest in northern Alabama. Although stream water flowing through the two different bedrock types differed significantly in chemical composition, there were no significant differences in total microbial and photosynthetic biomass in the sediments. In contrast, sedimentary microbial community structure differed between the bedrock types and was significantly correlated with stream water ion concentrations. A pattern of seasonal variation in microbial community structure was also observed. Further statistical analysis indicated dissolved organic matter (DOM) quality, which was previously shown to be influenced by geological variation, correlated with variation in bacterial community structure. These results indicate that the geology of underlying bedrock influences benthic microbial communities directly via changes in water chemistry and also indirectly via stream water DOM quality.

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