scholarly journals ISSUES IN ASSESSMENT OF POTENTIAL RADON HAZARD AT BUILDING SITES

2018 ◽  
Vol 11 (2) ◽  
pp. 37-44 ◽  
Author(s):  
N. K. Ryzhakova ◽  
K. O. Stavitskaya ◽  
A. A. Udalov
Keyword(s):  
Flux Density ◽  
Gas Permeability ◽  
Soil Surface ◽  
Geological Structure ◽  
Potential Hazard ◽  
Construction Sites ◽  
Building Site ◽  
Radon Flux ◽  
High Concentrations ◽  
Radon Potential

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.

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
Keyword(s):  
Flux Density ◽  
Soil Surface ◽  
National Standards ◽  
Measuring Instruments ◽  
Volumetric Activity ◽  
Standard Means ◽  
Radon Flux ◽  
Technical Solutions ◽  
Development Prospects ◽  
Physical Principles

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.

Estimating the amount and distribution of radon flux density from the soil surface in China

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

scholarly journals A new approach to the problem of assessing the radon hazard of building sites

2020 ◽  
Vol 13 (2) ◽  
pp. 57-64
Author(s):  
N. K. Ryzhakova ◽  
K. O. Stavitskaya ◽  
A. A. Udalov
Keyword(s):  
Soil Moisture ◽  
Flux Density ◽  
Activity Concentration ◽  
Strong Dependence ◽  
Soil Surface ◽  
Relevant Information ◽  
Labor Costs ◽  
Radon Flux ◽  
Andesite Basalt ◽  
Radium Activity

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.

The Specific Characteristics of Shock and Blast Impacts on Construction Sites

2021 ◽  
pp. 81-88
Author(s):  
A.A. Komarov ◽  
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Dynamic Loads ◽  
Potential Hazard ◽  
Construction Sites ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Plane Crash ◽  
Nuclear Plants ◽  
The Impact

The practices of hazardous and unique facilities’ construction imply that specific attention is paid to the issues of safety. Threats associated with crash impacts caused by moving cars or planes are considered. To ensure safety of these construction sites it is required to know the potential dynamic loads and their destructive capacity. This article considers the methodology of reducing dynamic loads associated with impacts caused by moving collapsing solids and blast loads to equivalent static loads. It is demonstrated that practically used methods of reduction of dynamic loads to static loads are based in schematization only of the positive phase of a dynamic load in a triangle forms are not always correct and true. The historical roots of this approach which is not correct nowadays are shown; such approach considered a detonation explosion as a source of dynamic load, including TNT and even a nuclear weapon. Application of the existing practices of reduction of dynamic load to static load for accidental explosions in the atmosphere that occur in deflagration mode with a significant vacuumization phase may cause crucial distortion of predicted loads for the construction sites. This circumstance may become a matter of specific importance at calculations of potential hazard of impacts and explosions in unique units — for instance, in the nuclear plants. The article considers a situation with a plane crash, the building structure load parameters generated at the impact caused by a plane impact and the following deflagration explosion of fuel vapors are determined.

Response of some vegetable crops to soil-applied halides

1992 ◽  
Vol 72 (4) ◽  
pp. 555-567 ◽  
Author(s):  
S. C. Sheppard ◽  
W. G. Evenden
Keyword(s):  
Key Words ◽  
Soil Surface ◽  
Competitive Interaction ◽  
The Other ◽  
Vegetable Crops ◽  
Tissue Concentrations ◽  
Industrial Pollutants ◽  
High Concentrations ◽  
Corn Kernels ◽  
Key Words Fluoride

The halide elements are environmentally important and share some common attributes. The heaviest, I, and the lighest, F, are quite toxic and are important industrial pollutants. They are also effectively retained in soils. The others, Cl and Br, can be accumulated to high concentrations in plants, are used in agriculture and are highly mobile in soils. This study investigated the behaviour of the halides in plots, outdoor lysimeters, and laboratory sorption and excised-root experiments. Sorption on soil was ordered as F > I > Br > Cl. Concentrations in plants were generally ordered as CI ≥ Br > > F ≥ I, the inverse of the sorption ordering, as expected. Older tissues, which were also closest to the soil surface, had higher concentrations, and sequestered tissues, such as corn kernels and cabbage heads, had lower concentrations. There was evidence of competitive interaction among the halides and with soil anions such as phosphate and sulfate. This competition reduced the toxicity of I and modified tissue concentrations of the halides, P and S. Another interesting interaction was an increase in Cl and I sorption on soil solids when there were elevated levels or the other halides. Overall, the study of the halides in combination enhanced our understanding of their individual behaviours. Key words: Fluoride, chloride, bromide, iodide, vegetable

Environmental Effects on Peppermint (Mentha piperita L.). I. Effect of Daylength, Photon Flux Density, Night Temperature and Day Temperature on the Yield and Composition of Peppermint Oil

1980 ◽  
Vol 7 (6) ◽  
pp. 685 ◽  
Author(s):  
RJ Clark ◽  
RC Menary
Keyword(s):  
Environmental Factors ◽  
Flux Density ◽  
Mentha Piperita ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Peppermint Oil ◽  
Oil Composition ◽  
Night Temperature ◽  
Low Concentrations ◽  
High Concentrations

Long days (16 h light), high photon flux density (1200 �Em-2 s-1.) and high night temperature (20°C) resulted in the highest oil yield. : Daylength, night temperature, day temperature and photon flux density were important interacting factors determining oil composition. The photosynthate model proposed by Burbott and Loomis (Plant Physiol., 1967, <B.42, 20-8) explained the effect of environmental factors with respect to pulegone, menthone and menthofuran. Factors favouring the maintenance of high levels of photosynthate resulted in high concentrations of menthone and low concentrations of pulegone and menthofuran. The photosynthate model does not explain the effect of environmental factors on several other monoterpenes.

Physical Properties and Structure of the Near Subsurface in the Săcel Area, Romania, from Shallow Seismic Measurements

2019 ◽  
Vol 24 (1) ◽  
pp. 151-158
Author(s):  
Ionelia Panea
Keyword(s):  
Wave Velocity ◽  
Signal To Noise Ratio ◽  
Soil Surface ◽  
Geological Structure ◽  
P Wave ◽  
S Wave ◽  
Sedimentary Deposits ◽  
Shallow Seismic ◽  
P Wave Velocity ◽  
Good Signal

Results are presented for shallow seismic reflection measurements performed southwest of Săcel village in Romania for the purpose of obtaining information about the geological structure in the near subsurface. The P-wave and S-wave velocity distributions were also obtained below the soil surface. The measurements were performed along a nearly linear profile on the top of an elongated hill. Most of the shot gathers were characterized by a good signal-to-noise ratio. A depth-converted migrated section was obtained after the processing of shot gathers, on which an image of sedimentary deposits with various thicknesses, separated by shallow faults until a depth of about 80 m, were observed. The P-wave and S-wave velocity-depth models for two segments were of considerable interest for a geotechnical study proposed for the construction of a windmill park. The two- and three-layered P-wave velocity-depth models were comparable until depths of about 10 m after first-arrival traveltime inversions. The lateral variations in the subsurface geological structure and lithology reflected the variations in the P-wave velocity values from both models. The S-wave velocity-depth models for comparable depth intervals were similar to those from the P-wave velocity-depth models. Reliable S-wave velocity distributions were obtained after inversion of fundamental-mode and higher-mode surface waves.

scholarly journals Comparison of Rain Effects on Splash Dispersal of Three Colletotrichum Species Infecting Strawberry

1999 ◽  
Vol 89 (7) ◽  
pp. 555-563 ◽  
Author(s):  
N. Ntahimpera ◽  
L. L. Wilson ◽  
M. A. Ellis ◽  
L. V. Madden
Keyword(s):  
Flux Density ◽  
Soil Surface ◽  
Selective Medium ◽  
Spore Density ◽  
Deposition Flux ◽  
Closely Related Species ◽  
Colletotrichum Species ◽  
Splash Dispersal ◽  
Significant Difference ◽  
The Media

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.

scholarly journals Rain Splash Dispersal of Gibberella zeae Within Wheat Canopies in Ohio

2004 ◽  
Vol 94 (12) ◽  
pp. 1342-1349 ◽  
Author(s):  
P. A. Paul ◽  
S. M. El-Allaf ◽  
P. E. Lipps ◽  
L. V. Madden
Keyword(s):  
Flux Density ◽  
Soil Surface ◽  
Selective Medium ◽  
Gibberella Zeae ◽  
Spore Density ◽  
Rain Intensity ◽  
Head Blight ◽  
Splash Dispersal ◽  
Rain Splash ◽  
Maize Kernels

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.

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