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1.
Radiat Environ Biophys ; 45(2): 105-14, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16733725

ABSTRACT

The release of radioactive particles through large gaps in the containment of the destroyed Chernobyl reactor was assessed during two measurement periods. In 1996-1999, a total radionuclide flow rate of 274 Bq s(-1) or 8.64 x 10(9) Bq year(-1) was determined. These releases were predominantly due to (137)Cs (78.5%), (90)Sr (21.1%), and (239+240)Pu (0.4%). The mean activity concentration in the aerosol measured directly at the gaps was about 240 mBq m(-3) with an activity median aerodynamic diameter (AMAD) of 2.4 microm for (137)Cs, 120 mBq m(-3) with an AMAD in the range 3.1-13 microm for (90)Sr, 1.8 mBq m(-3) with an AMAD in the range 3.5-11 microm for (239+240)Pu, and 2.0 mBq m(-3) with an AMAD of 1.5 microm for (241)Am. The resulting total inhalation dose rate calculated close to the gaps was about 100 nSv h(-1). In the near environment, the mean (137)Cs activity in the aerosol was 2.2 mBq m(-3) with an AMAD of 2.2 microm, which gave rise to an inhalation dose rate of about two orders of magnitude lower than the corresponding dose rate at the gaps. Occasionally, however, dose levels were measured in the near environment that were similar to those at the gaps. In 2000-2003, lower activity concentrations were observed. The decrease was more pronounced at the gaps than in the near environment. The results indicate that effective dose due to inhalation must be considered for the dose assessment of construction workers who will be deployed at the Chernobyl site to reconstruct the old or to build the new Shelter, in the future.


Subject(s)
Air Pollutants, Radioactive/analysis , Chernobyl Nuclear Accident , Inhalation Exposure/analysis , Radiation Monitoring , Aerosols , Humans , Models, Theoretical , Ukraine
2.
Gig Sanit ; (1): 30-5, 2001.
Article in Russian | MEDLINE | ID: mdl-11236471

ABSTRACT

Retransfer of radionuclides on the condensation trails of Chernobyl radioactive fallouts during forest fires has been experimentally evaluated and their mathematical transfer model verified. It has been shown that radionuclide retransfer will make no great impact on additional pollution of an area even under the most unfavourable conditions. The contribution of convective and non-convective components of transfer to the formation of a radioactive aerosol concentration field has been assessed. Time course of changes in the concentration of radioactive aerosol and its dispersive composition are shown in different phases of fire and at different distance from its source.


Subject(s)
Air Pollution, Radioactive , Cesium Radioisotopes , Fires , Power Plants , Radioactive Hazard Release , Aerosols , Ecology , Humans , Middle Aged , Models, Theoretical , Radioactive Fallout , Soil Pollutants, Radioactive , Temperature , Ukraine , Weather
3.
Biofizika ; 39(4): 588-93, 1994.
Article in Russian | MEDLINE | ID: mdl-7981269

ABSTRACT

Calorimetry and dielectrometry in the millimeter wave range have been applied to demonstrate a possibility for determination of heat capacity of bound water in biopolymer matrices in solution is shown. Variation of the hydration level of human serum albumin caused by the variation of temperature and protein concentration is described. Application of two methods based on comparison of calorimetric and dielectric data on protein solutions at different temperatures and concentrations have produced similar values of the heat capacity of bound water in the protein hydration shell (approximately 3 J/g.K).


Subject(s)
Serum Albumin/chemistry , Water/chemistry , Biopolymers , Calorimetry , Electricity , Hot Temperature , Humans
4.
Biofizika ; 39(1): 50-7, 1994.
Article in Russian | MEDLINE | ID: mdl-8161587

ABSTRACT

Hydration and structure of Li DNA in films and solutions have been investigated by methods of IR spectroscopy, piezogravimentry, UHF dielectrometry, and microcalorimetry. The hydration energy and the water sorption range in which the DNA undergoes the transition from the unordered state to the B-form have been determined, making it possible to evaluate the contribution of water molecules of the DNA hydration shell to the total stabilization energy of the DNA helical structure.


Subject(s)
DNA/chemistry , Nucleic Acid Conformation , Water/chemistry , Calorimetry , Electric Conductivity , Spectrophotometry, Infrared
5.
Biofizika ; 38(5): 768-90, 1993.
Article in Russian | MEDLINE | ID: mdl-8241309

ABSTRACT

The review of original and literary data obtained by the different physical methods on the structure, mechanical, electrostatic and energetic properties of DNA-ions-water system was done. On the basis of the examined results the main problem of DNA structure formation its dynamic and stability were discussed.


Subject(s)
DNA/chemistry , Water/chemistry , Base Sequence , Electricity , Molecular Sequence Data , Nucleic Acid Conformation
7.
Mol Biol (Mosk) ; 10(2): 568-75, 1976.
Article in Russian | MEDLINE | ID: mdl-1053042

ABSTRACT

A differential method is described for measuring dielectric constants and losses in aqueous protein solutions at millimetrerange wavelengths. Employment of the method allows to improve the accuracy of determining the degree of hydratation. A method has also been suggested for taking into account the contribution of ions to the dielectric constant of solutions. The differential method was used to study hydratation of nine globular proteins. The data obtained are compared with the corresponding values provided by other experimental techniques and with theoretical predictions based on some models of hydratation. Good agreement is obtained with results provided by the isopiestic and NMR techniques. The discrepancy shown for hemoglobin is discussed in the paper. As has been shown, the dielectric method registers a monomolecular surface layer of water only. With pH varying between 4.0 and 3.2, a significant increase is observed in the hydratation of serum albumin. Presumably, this effect is connected with a N--F conformational transition.


Subject(s)
Proteins , Electrochemistry , Endopeptidases , Hemoglobins , Magnetic Resonance Spectroscopy , Methods , Protein Conformation , Water
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