Chemical Processes in the Stratosphere and Troposphere

2008 ◽  
pp. 209-252 ◽  
Keyword(s):  
Chemical Processes

The chemical processes of memory

1963 ◽  
Author(s):  
E. Roy John
Keyword(s):  
Chemical Processes

Thermodynamics of Chemical Processes

1999 ◽  
Vol 213 (Part_1) ◽  
pp. 107-107
Author(s):  
U. Messow
Keyword(s):  
Chemical Processes

Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures

1991 ◽  
Vol 223 ◽  
Author(s):  
Hans P. Zappe ◽  
Gudrun Kaufel
Keyword(s):  
Chemical Processes ◽  
Low Energy ◽  
Electrical Behavior ◽  
Rapid Thermal Anneal ◽  
High Temperature Anneal ◽  
Significant Damage ◽  
Low Energies ◽  
Long Time ◽  
Physical Plasma

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.

THE FEATURES OF BIODESTRUCTION PROCESSES OF THE SURFACES OF HYDRAULIC ENGINEERING CONSTRUCTIONS

2017 ◽  
Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Environmental Factors ◽  
Food Chain ◽  
Building Materials ◽  
Microbial Growth ◽  
Mineralogical Composition ◽  
Mechanical Action ◽  
Chemical Processes ◽  
Hydraulic Engineering ◽  
Optimal Conditions

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.

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