Radiation-Chemical Yields of The Primary Products of Water Radiolysis and Their Dependence on Various Factors

1971 ◽  
pp. 123-170
Keyword(s):  
Water Radiolysis ◽  
Radiation Chemical ◽  
Primary Products

Mechanism of radiation purification of polluted water and wastewater

2001 ◽  
Vol 44 (5) ◽  
pp. 131-139 ◽  
Author(s):  
A.K. Pikaev
Keyword(s):  
Municipal Wastewater ◽  
Paper Mill ◽  
Petroleum Products ◽  
Polluted Water ◽  
Water Radiolysis ◽  
Primary Products ◽  
Removal Of Heavy Metals ◽  
Water And Wastewater ◽  
Cadmium Lead

The paper summarizes the results of the studies on radiation purification of polluted water and wastewater conducted in the author's laboratory in cooperation with other institutions. The removal of heavy metals (cadmium, lead, chromium and mercury) from water and wastewater, the purification of wastewater from surfactant and petroleum products, molasses distillery slops, municipal wastewater in the aerosol flow, river water from colored natural organic pollutants, wastewater of dyeing complex and paper mill, the decomposition of some dyes, hydrogen peroxide, chlorine-containing organic compounds, formic acid, etc. were investigated in detail. As a rule, electron-beam treatment in combination with ordinary methods (biological, coagulation, adsorption, flotation, etc.) was used. The main attention is paid to the mechanism of purification of the studied systems. The role of redox reactions of primary products of water radiolysis and secondary short-lived species formed from pollutants, formation of precipitates capturing the pollutants etc. is discussed.

Trapped atoms and radicals in rigid solvents

1955 ◽  
Vol 230 (1182) ◽  
pp. 399-414 ◽  
Keyword(s):  
Gas Phase ◽  
Chemical Processes ◽  
Trapped Atoms ◽  
General Applicability ◽  
Radiation Chemical ◽  
Benzyl Radical ◽  
Primary Products ◽  
Aromatic Radicals ◽  
Reactive Radicals ◽  
First Time

A number of very reactive radicals and atoms prepared by photolysis in rigid hydrocarbon glasses at the temperature of liquid nitrogen have been detected by their absorption spectra. Thus ethyl iodide dissociates to iodine atoms which only recombine to give I 2 when the glass is softened. Similarly CS 2 and ClO 2 give CS and CIO which can be detected spectroscopically in the frozen glass. Toluene and other benzyl derivatives yield the benzyl radical, and the spectra of a number of similar unstable aromatic radicals have been recorded for the first time. Most of these radicals have lifetimes of less than 1 ms at comparable concentrations in the gas phase or in ordinary solutions, but have been observed for many hours in the rigid glass. The method should be of general applicability for the study of the primary products of photochemical or radiation chemical processes.

scholarly journals An Alternative Conceptual Model for the Spent Nuclear Fuel–Water Interaction in Deep Geologic Disposal Conditions

2021 ◽  
Vol 11 (18) ◽  
pp. 8566
Author(s):  
Barbara Pastina ◽  
Jay A. LaVerne
Keyword(s):  
Conceptual Model ◽  
Nuclear Fuel ◽  
Release Rate ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Water Radiolysis ◽  
Spent Fuel ◽  
Radiation Chemical ◽  
Radionuclide Release

For the long-term safety assessment of direct disposal of spent nuclear fuel in deep geologic repositories, knowledge on the radionuclide release rate from the UO2 matrix is essential. This work provides a conceptual model to explain the results of leaching experiments involving used nuclear fuel or simulant materials in confirmed reducing conditions. Key elements of this model are: direct effect of radiation from radiolytic species (including defects and excited states) in the solid and in the first water layers in contact with its surface; and excess H2 may be produced due to processes occurring at the surface of the spent fuel and in confined water volumes, which may also play a role in keeping the spent fuel surface in a reduced state. The implication is that the fractional radionuclide release rate used in most long-term safety assessments (10−7 year−1) is over estimated because it assumes that there is net UO2 oxidation caused by radiolysis, in contrast with the alternative conceptual model presented here. Furthermore, conventional water radiolysis models and radiation chemical yields published in the literature are not directly applicable to a heterogeneous system such as the spent fuel–water interface. Suggestions are provided for future work to develop more reliable models for the long-term safety assessment of spent nuclear fuel disposal.

Role of the exosporial membrane in attachment and germination of C. sporogenes

1993 ◽  
Vol 51 ◽  
pp. 38-39
Author(s):  
B.J. Panessa-Warren ◽  
G.T. Tortora ◽  
J.B. Warren
Keyword(s):  
Enzymatic Degradation ◽  
Light Transmission ◽  
Extended Period ◽  
Growth Conditions ◽  
Clostridium Sporogenes ◽  
Radiation Chemical ◽  
Physical Trauma ◽  
Extended Contact ◽  
Cold Pressure

Some bacteria are capable of forming highly resistant spores when environmental conditions are not adequate for growth. Depending on the genus and species of the bacterium, these endospores are resistant in varying degrees to heat, cold, pressure, enzymatic degradation, ionizing radiation, chemical sterilants,physical trauma and organic solvents. The genus Clostridium, responsible for botulism poisoning, tetanus, gas gangrene and diarrhea in man, produces endospores which are highly resistant. Although some sporocides can kill Clostridial spores, the spores require extended contact with a sporocidal agent to achieve spore death. In most clinical situations, this extended period of treatment is not possible nor practical. This investigation examines Clostridium sporogenes endospores by light, transmission and scanning electron microscopy under various dormant and growth conditions, cataloging each stage in the germination and outgrowth process, and analyzing the role played by the exosporial membrane in the attachment and germination of the spore.

Targeted Delivery of Natural Bioactives and Lipid-nanocargos against Signaling Pathways Involved in Skin Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Mohammad Kashif Iqubal ◽  
Aiswarya Chaudhuri ◽  
Ashif Iqubal ◽  
Sadaf Saleem ◽  
Madan Mohan Gupta ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Signaling Pathways ◽  
Signaling Pathway ◽  
Targeted Delivery ◽  
Skin Pigmentation ◽  
Wnt Signaling Pathway ◽  
Human Beings ◽  
Radiation Chemical ◽  
Cell Leukemia Virus Type ◽  
Human T Cell

: At present, skin cancer is a widespread malignancy in human beings. Among diverse population types, Caucasian populations are much more prone in comparison to darker skin populations due to the comparative lack of skin pigmentation. Skin cancer is divided into malignant and non-melanoma skin cancer, which is additionally categorized as basal and squamous cell carcinoma. The exposure to ultraviolet radiation, chemical carcinogen (polycyclic aromatic hydrocarbons, arsenic, tar, etc.), and viruses (herpes virus, human papillomavirus, and human T-cell leukemia virus type-1) are major contributing factors of skin cancer. There are distinct pathways available through which skin cancer develops, such as the JAKSTAT pathway, Akt pathway, MAPKs signaling pathway, Wnt signaling pathway, to name a few. Currently, several targeted treatments are available, such as monoclonal antibodies, which have dramatically changed the line of treatment of this disease but possess major therapeutic limitations. Thus, recently many phytochemicals have been evaluated either alone or in combination with the existing synthetic drugs to overcome their limitations and have found to play a promising role in the prevention and treatment. In this review, complete tracery of skin cancer, starting from the signaling pathways involved, newer developed drugs with their targets and limitations along with the emerging role of natural products alone or in combination as potent anticancer agents and their molecular mechanism involved has been discussed. Apart from this, various nanocargos have also been mentioned here, which can play a significant role in the management and treatment of different types of skin cancer.

Primary Products and Economic Growth: Rejoinder

1967 ◽  
Vol 75 (6) ◽  
pp. 881-885 ◽  
Author(s):  
Edward J. Chambers ◽  
Donald F. Gordon
Keyword(s):  
Economic Growth ◽  
Primary Products
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