scholarly journals A model to predict the kinetics of direct (endogenous) virus inactivation by sunlight at different latitudes and seasons, based on the equivalent monochromatic wavelength approach

2021 ◽  
pp. 117837
Author(s):  
Ángela García-Gil ◽  
Javier Marugán ◽  
Davide Vione
1961 ◽  
Vol 7 (2) ◽  
pp. 135-139 ◽  
Author(s):  
John R. Polley

The use of gamma radiation from a cobalt-60 cell for the preparation of non-infective diagnostic antigens for influenza A, influenza B, mumps, smallpox, and herpes simplex has been investigated. It was found possible to destroy the infectivity while retaining most of the complement-fixing activity of all these antigens. The degree of purity of the antigen had no apparent effect on the rate of inactivation, as is the case when formaldehyde is used. Under the experimental conditions described, the degree of inactivation depended on the total amount of radiation applied and not on the dose rate. The kinetics of virus inactivation make it possible to calculate the amount of radiation required to destroy infectivity completely and yet retain most of the antigenicity. If necessary it is possible to apply an additional calculated amount of radiation to destroy residual infectivity without causing loss of antigenicity. Gamma radiation appears to be superior to formaldehyde treatment for the preparation of the herpes simplex antigen which is particularly sensitive to heat and to formaldehyde.


2008 ◽  
Vol 99 (6) ◽  
pp. 1384-1391 ◽  
Author(s):  
Mark R. Bailey ◽  
Dayue Chen ◽  
Warren R. Emery ◽  
Peter K. Lambooy ◽  
Juliana Nolting ◽  
...  

2020 ◽  
Author(s):  
Nicole C. Rockey ◽  
James B. Henderson ◽  
Kaitlyn Chin ◽  
Lutgarde Raskin ◽  
Krista R. Wigginton

AbstractDisinfection strategies are commonly applied to inactivate pathogenic viruses in water, food, air, and on surfaces to prevent the spread of infectious diseases. Determining how quickly viruses are inactivated to mitigate health risks is not always feasible due to biosafety restrictions or difficulties with virus culturability. Therefore, methods that would rapidly predict kinetics of virus inactivation by UV254 would be valuable, particularly for emerging and difficult-to-culture viruses. We conducted a rapid systematic literature review to collect high-quality inactivation rate constants for a wide range of viruses. Using these data and basic virus information (e.g., genome sequence attributes), we developed and evaluated four different model classes, including linear and non-linear approaches, to find the top performing prediction model. For both the (+) ssRNA and dsDNA virus types, multiple linear regressions were the top performing model classes. In both cases, the cross-validated root mean squared relative prediction errors were similar to those associated with experimental rate constants. We tested the models by predicting and measuring inactivation rate constants for two viruses that were not identified in our systematic review, including a (+) ssRNA mouse coronavirus and a dsDNA marine bacteriophage; the predicted rate constants were within 7% and 71% of the experimental rate constants, respectively. Finally, we applied our models to predict the UV254 rate constants of several viruses for which high-quality UV254 inactivation data are not available. Our models will be valuable for predicting inactivation kinetics of emerging or difficult-to-culture viruses.


2018 ◽  
Vol 117 ◽  
pp. 33-42 ◽  
Author(s):  
Quelen Letícia Shimabuku ◽  
Tânia Ueda-Nakamura ◽  
Rosangela Bergamasco ◽  
Márcia Regina Fagundes-Klen

1983 ◽  
Vol 45 (3) ◽  
pp. 760-765 ◽  
Author(s):  
W. N. Cramer ◽  
W. D. Burge ◽  
K. Kawata

Author(s):  
J. F. DeNatale ◽  
D. G. Howitt

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.


Author(s):  
R. J. Lauf

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.


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


Author(s):  
L. J. Chen ◽  
L. S. Hung ◽  
J. W. Mayer

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.


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