Status and development prospects of standard means for reproducing units of volumetric activity of radon and thoron and radon flux density from the soil surface

2020 ◽  
pp. 69-73
Author(s):  
S.G. Birjukov ◽  
O.I. Kovalenko ◽  
A.A. Orlov

The approach to creating standard means for reproducing units of volumetric activity of radon and thoron and flux density of radon from the soil surface is described based on the physical principles of reproducing these units of quantities and using as technical means for reproducing bubblers with a radioactive solution of radium salt, reference capacities of known volume, emanation chambers for generation of a toron, a gamma spectrometer with a semiconductor detector from highly pure germanium and radon radiometers. Reproduction consists in the physical realization of units in accordance with their definition as applied to the formation of radon and thoron in the radioactive rows of radium and thorium. The proposed approach will allow to determine the structural, structural and other technical solutions of standard measuring instruments, as well as specific techniques and methods of working with them. The creation of standard tools and technologies for reproducing units of volumetric activity of radon and thoron and the density of radon flux from the soil surface will ensure the unity and reliability of measurements in the field of ionizing radiation, traceability of units and bringing the characteristics of national standards in line with world achievements.

2008 ◽  
Vol 99 (7) ◽  
pp. 1143-1148 ◽  
Author(s):  
Weihai Zhuo ◽  
Qiuju Guo ◽  
Bo Chen ◽  
Guan Cheng
Keyword(s):  

2020 ◽  
Vol 13 (2) ◽  
pp. 57-64
Author(s):  
N. K. Ryzhakova ◽  
K. O. Stavitskaya ◽  
A. A. Udalov

Radon and its daughter products create more than half dose from all natural radiation sources. The radon entering the buildings is emitted mainly from soils lying at the base of the foundation. Therefore, before carrying out construction work, the radon hazard of the construction area are determined. In the Russian Federation, the radon hazard of an area can be determined using radon flux density measured on the soil surface. To date, radon researchers came to the conclusion that the geology of the territory affects the amount of radon released from the soil surface. However, there are almost no studies devoted to the release of radon from the surface of various soil types. The paper presents the measuring results of the radon flux density on the surface of loess loams, porcelain clay, argillaceous slate, sand-and-gravel sediment, rocky limestone, clayey limestone, andesite-basalt porphyrite and quartzrock. The measurements were carried out by the accumulation chamber method using the Alfarad Plus measuring complex. Also, measuring radium activity concentration and soil moisture were carried out. The research demonstrates that, depending on the type of soil, the amount of radon emanating from its surface differs by more than an order of magnitude. The largest values of radon flux density of ~ 800 mBq∙m-2s-1 were recorded for andesite-basalt porphyrite and quartzrock. The smallest ones of ~ 40 mBq∙m-2s-1 were registered for loess loams and argillaceous slates. For soils consisting of small sand and clay grains, a rather strong dependence of the radon flux density on soil moisture was found. When measuring soils with low moisture (2-6%), a proportional dependence of the radium activity concentration on the amount of radon emanating from the soil surface is not observed. The types of soils that lie at the foundations of the buildings, and their physical properties can be used as the basis for classifying building sites according to the degree of radon hazard. Relevant information may be provided by organizations engaged in design and survey work at building plots. The approach proposed in the work for assessing radon hazard will allow avoiding labor-intensive measurements of radon and thereby reduce the financial, material and labor costs of building construction.


2018 ◽  
Vol 11 (2) ◽  
pp. 37-44 ◽  
Author(s):  
N. K. Ryzhakova ◽  
K. O. Stavitskaya ◽  
A. A. Udalov

High concentrations of radon in the premises leads to a risk of lung cancer for the population. In this regard, in the production of design and construction works, an assessment is made of the potential hazard of radon in the construction sites. At the present, the unified approach to methodology of assessment is not developed. Abroad, various categorical and numerical values, such as radon potential or radon index, are used as criteria for radon hazard. In different countries, these criteria are determined using various parameters: uranium / radium concentration, radon volumetric activity in soil air and premises, gas permeability of soils, geological structure of underlying rocks, dose rate of gamma radiation. Studies conducted abroad show that the parameters used, as a rule, do not correlate with the amount of radon entering buildings during its operation. In the Russian Federation, the radon flux density measured on the soil surface is used to estimate the potential radon hazard of a building site. Applied today method of potential radon hazard assessment has one general drawback. It is low reliability of results. Such a quality of assessments obtained by measuring the radon flux density is due to the variability in the values of this value and to the measurement of the surface of the soil. The paper discusses the results of measuring the radon flux density obtained by the methods of «accumulation chambers» and «carbon adsorbers» in the summer periods of 2014, 2016 and 2017. It was confirmed that the strongest influence on the values and variability of radon flux density is exerted by precipitation. The paper presents the results of radon flux density measurements on the soil surface, as well as on the surface of dense loams lying at depths of 0.5 m and 1.5 m. It is shown that the radon flux density measured on the soil surface is two to three times smaller than the values of this value measured on the surface of dense rocks. It is important to note that the lowest variability of the results (20%) was observed in 2014, when measurements were made on the surface of dense loams during dry, stable weather.


2022 ◽  
Author(s):  
Aleksey Burkov ◽  
Viktor Mihanoshin

The monograph provides an overview and analysis of ship's rowing electrical installations, modern scientific and technical solutions aimed at improving the theory and practice of electrical systems of ship propulsion systems are considered. Solutions of urgent problems related to the development of rowing electric installations of small-tonnage vessels based on the introduction of combined power plants, including electrochemical sources of electricity (batteries), are proposed. It is intended for scientific and educational purposes and is aimed at specialists in the field of ship power engineering, cadets and students of electromechanical specialties of educational institutions.


1999 ◽  
Vol 89 (7) ◽  
pp. 555-563 ◽  
Author(s):  
N. Ntahimpera ◽  
L. L. Wilson ◽  
M. A. Ellis ◽  
L. V. Madden

Rain simulation studies were performed to compare splash dispersal of three Colletotrichum species: C. acutatum (C. acutatum-O isolate from Ohio and C. acutatum-M isolate from Mississippi), C. fragariae (isolate from Mississippi), and C. gloeosporioides (isolate from Florida). Conidial dispersal was assessed by counting colonies formed from spore-bearing splash droplets deposited in sheltered petri plates containing a selective medium. Colonies were converted to number of conidia based on germination rates of spores on the media. The interpolated total number of dispersed conidia over a 61 min rain and 72 cm from the point source (Σ) was calculated. For all species, a rain intensity of 30-mm/h resulted in significantly greater dispersal than an intensity of 11-mm/h. C. fragariae had the lowest amount of spore dispersal, and C. acutatum-O had the highest dispersal. C. acutatum-M and C. gloeosporioides were intermediate in magnitude of conidial splash dispersal. However, differences were directly attributed to differences in spore density per fruit at the source. When Σ was corrected for source strength (Σr), the species were very similar, with only C. acutatum-M having a mean Σr significantly less than the others. Proportions and rates of spore removal (per minute) from source fruits were higher for C. acutatum-O and C. gloeosporioides than for other isolates. Wash-off rates of conidia deposited on healthy fruits were the same for all species. Deposition flux density of spores that had been uniformly sprayed over the entire soil surface of the experimental area was affected by species. A significant difference in means was observed between C. acutatum and C. fragariae—the latter had a somewhat lower flux density. This is the first demonstration that closely related species infecting the same plant species are similar in terms of splash dispersal.


2018 ◽  
Vol 251 ◽  
pp. 02010 ◽  
Author(s):  
Mikhail Slesarev ◽  
Valery Telichenko ◽  
Nguyen Dinh Dap

For the first time, formation of innovative methods for ecological safety of construction which called to treat as a result a complex of new technical solutions (more than 15 patents for inventions) focused on the solution of ecological safety problem in construction areas, and also for the first time the set four projects of national standards «“Green” standard. “Green” technologies of living environment and “green” innovative production»: “Terms and definitions”; “Classification”; “Criteria of reference”; “conformity assessment according to the requirements of the green standards. General provisions”.


2004 ◽  
Vol 94 (12) ◽  
pp. 1342-1349 ◽  
Author(s):  
P. A. Paul ◽  
S. M. El-Allaf ◽  
P. E. Lipps ◽  
L. V. Madden

Rain splash dispersal of Gibberella zeae, causal agent of Fusarium head blight of wheat, was investigated in field studies in Ohio between 2001 and 2003. Samplers placed at 0, 30, and 100 cm above the soil surface were used to collect rain splash in wheat fields with maize residue on the surface and fields with G. zeae-infested maize kernels. Rain splash was collected during separate rain episodes throughout the wheat-growing seasons. Aliquots of splashed rain were transferred to petri dishes containing Komada's selective medium, and G. zeae was identified based on colony and spore morphology. Dispersed spores were measured in CFU/ml. Intensity of splashed rain was highest at 100 cm and ranged from 0.2 to 10.2 mm h-1, depending on incident rain intensity and sampler height. Spores were recovered from splash samples at all heights in both locations for all sampled rain events. Both macroconidia and ascospores were found based on microscopic examination of random samples of splashed rain. Spore density and spore flux density per rain episode ranged from 0.4 to 40.9 CFU cm-2 and 0.4 to 84.8 CFU cm-2 h-1, respectively. Spore flux density was higher in fields with G. zeae-infested maize kernels than in fields with maize debris, and generally was higher at 0 and 30 cm than at 100 cm at both locations. However, on average, spore flux density was only 30% lower at 100 cm (height of wheat spikes) than at the other heights. The log of spore flux density was linearly related to the log of splashed rain intensity and the log of incident rain intensity. The regression slopes were not significantly affected by year, location, height, and their interactions, but the intercepts were significantly affected by both sampler height and location. Thus, our results show that spores of G. zeae were consistently splash dispersed to spike heights within wheat canopies, and splashed rain intensity and spore flux density could be predicted based on incident rain intensity in order to estimate inoculum dispersal within the wheat canopy.


Author(s):  
A. A. Bubis ◽  
I. R. Gizyatullin ◽  
A. I. Dottuev ◽  
T. V. Nazmeeva

Building structural systems with light gauge steel framing technology are steadily gaining popularity due to their huge advantages over traditional technical solutions. As a result of the competitiveness inherent in LGSF technology, its application is gradually increasing in the manufacture of both bearing and nonbearing structures. At the same time, the actual absence of national standards for seismic design requires the development of programs and the implementation of research and development work to study the behavior of LGSF buildings in the conditions of seismic impact. The article touches upon the main problems of antiseismic construction of LGSF buildings and presents the results of domestic and foreign research.


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