scholarly journals Analysis of the hydrogeological conditions in Bulgaria in connection with the radon potential

2021 ◽  
Vol 82 (3) ◽  
pp. 201-203
Author(s):  
Dimitar Antonov ◽  
Mila Trayanova ◽  
Sava Kolev ◽  
Aglaida Toteva ◽  
Aleksey Benderev ◽  
...  
Keyword(s):  
Noble Gas ◽  
High Mobility ◽  
Groundwater Table ◽  
Soil Gas ◽  
Hydrogeological Conditions ◽  
Different Types ◽  
Screening Assessment ◽  
Diffusion And Convection ◽  
Radon Potential ◽  
226Ra Content

Natural radon (222Rn) is a radioactive noble gas that occurs in every rock or soil due to the content of radium (226Ra), part of the 238U family, in the lithosphere. Different types of rocks and soils possess different 226Ra content and different permeability. Radon has high mobility and is driven by diffusion and convection with the soil gas throughout connected and water-unsaturated pores and/or cracks in permeable rocks and soils. Therefore, the radon potential of the area could depend on hydrogeology and its particular settings. The study deals with the general characteristics of the groundwater depths in Bulgaria based on the published since 1960’s sources. After analysis of the collected data several distinct regions have been elaborated based on different depth of the groundwater table regarding lithological, tectonic and geomorphological conditions. In addition, zones for screening assessment of groundwater table influence of radon potential have been precised.

A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

1994 ◽  
Vol 52 ◽  
pp. 700-701
Author(s):  
S. Wisutmethangoon ◽  
T. F. Kelly ◽  
J.E. Flinn
Keyword(s):  
Stainless Steels ◽  
High Mobility ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Gas Atomization ◽  
Cavity Formation ◽  
Nucleation Sites ◽  
Heat Treated ◽  
Different Types ◽  
Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

scholarly journals General 1-D hydrogeological model for temporal near-surface loess saturation assessment for the needs of radon potential mapping

2021 ◽  
Vol 82 (3) ◽  
pp. 219-221
Author(s):  
Sava Kolev
Keyword(s):  
High Mobility ◽  
Domain Modeling ◽  
Hydrogeological Model ◽  
Saturation State ◽  
Near Surface ◽  
Infiltration Model ◽  
Potential Mapping ◽  
Radon Potential ◽  
Usual State ◽  
Constant Source

Radon gas has high mobility and is driven by advection and diffusion with the soil gas throughout connected and water-unsaturated pores and/or cracks in permeable rocks and soils. Hence the radon potential of the area could be dependent on not only geology as a constant source of radon but also from the changes of the saturation state of the ground. The loess complex, characterized by its permeability and usual state of unsaturation, covers 10% of the Bulgarian territory. The study deals with the principles of unsaturated domain modeling. An attempt of generic vertical infiltration model coinciding with the most upper part of loess vadose zone was performed.

scholarly journals Mobility of black carbon in drained peatland soils

2007 ◽  
Vol 4 (3) ◽  
pp. 425-432 ◽  
Author(s):  
J. Leifeld ◽  
S. Fenner ◽  
M. Müller
Keyword(s):  
Thermal Oxidation ◽  
Black Carbon ◽  
Water Saturation ◽  
High Mobility ◽  
Organic Soil ◽  
Historical Record ◽  
Scanning Calorimetry ◽  
Different Types ◽  
Ploughing Depth ◽  
Combustion Residues

Abstract. Amount, stability, and distribution of black carbon (BC) were studied at four sites of a large peatland ("Witzwil") formerly used as a disposal for combustion residues from households to derive BC displacement rates in the profile. Possible artefacts from thermal oxidation with Differential Scanning Calorimetry (DSC) on BC quantification of C-rich deposits were inferred by choosing three sites from a second peatland with no historical record of waste disposal as a reference ("Seebodenalp"). All sites were under grassland at time of sampling, but were partially cropped in the past at Witzwil. Mean BC contents in topsoils of Witzwil ranged from 10.7 to 91.5 (0–30 cm) and from 0.44 to 51.3 (30–140 cm) mg BC g−1 soil, corresponding to BC/OC ratios of 0.04 to 0.3 (topsoil) and 0.02 to 0.18 (deeper soil). At three sites of Seebodenalp, BC was below the detection limit of 0.4 mg g−1 organic soil, indicating negligible formation of BC during thermal oxidation of peat. 13C NMR spectra corroborated the high BC contents at Witzwil. The data support a considerable vertical transport of BC given that soils were ploughed not deeper than 30 cm since abandonment of waste application about 50 years ago. The total amount of BC in the Witzwil profiles ranged from 3.2 to 7.5 kg BC m−2, with 21 to 69 percent of it stemming from below the former ploughing depth. Under the premise of negligible rates of BC consumption since abandonment of waste application, minimum BC transport rates in these peats are 0.6 to 1.2 cm a−1. The high mobility of BC might be explained by high macro-pore volumes in combination with occasional water saturation. By means of DSC peak temperatures, different types of BC could be distinguished, with deeper horizons containing BC of higher thermal stability. Application of combustion residues likely involved a mixture of various BC types, of which thermally more stable ones, most likely soots, were preferentially transported downwards.

Recommended urban storm water infiltration devices for different types of run-off under varying hydrogeological conditions

2008 ◽  
Vol 8 (4) ◽  
pp. 231-238 ◽  
Author(s):  
Patricia Göbel ◽  
Julia Zimmermann ◽  
Christoph Klinger ◽  
Holger Stubbe ◽  
Wilhelm G. Coldewey
Keyword(s):  
Water Infiltration ◽  
Storm Water ◽  
Hydrogeological Conditions ◽  
Run Off ◽  
Different Types ◽  
Urban Storm

Geogenic radon potential mapping using geospatial analysis of multiple radon-related variables: a case study from Southeastern Ireland

2020 ◽  
Author(s):  
Mirsina Mousavi ◽  
Quentin Crowley
Keyword(s):  
Regression Model ◽  
Radon Concentration ◽  
Indoor Radon ◽  
Spatial Regression ◽  
Geostatistical Analysis ◽  
Soil Gas ◽  
Natural Radiation ◽  
Spatial Regression Model ◽  
Soil Gas Radon ◽  
Radon Potential

<p>A detailed investigation of geogenic radon potential (GRP) was carried out using geostatistical analysis on multiple radon-related variables to evaluate natural radiation in an area of Southeast Ireland. The geological setting of the study area includes basal Devonian sandstones and conglomerates overlying an offshoot of the Caledonian Leinster Granite, which intrudes Ordovician sediments. The Ordovician sediments contain traces of autunite (Ca(UO<sub>2</sub>)2(PO<sub>4</sub>)<sub>2</sub>·10–12H<sub>2</sub>O), which is a uranium-bearing mineral and a source of radon. To model radon release potential at different locations, a spatial regression model was developed in which soil gas radon concentration measured in-situ using a Radon RM-2 detector was considered as a response value. Proxy variables such as local geology, soil types, terrestrial gamma dose rates, radionuclide concentrations from airborne radiometric surveys, soil gas permeability, distance from major faults and a Digital Terrain Model were used as the main predictors. Furthermore, the distribution of indoor radon concentration was simulated using a soil-indoor transfer factor. Finally, the workability of the proposed GRP model was tested by evaluating the correlation between previously measured indoor radon concentrations and the estimated values by the GRP model at the same measurement locations. This model can also be used to estimate the GRPs of other areas where radon-related proxy values are available.        </p><p><strong>Keywords:</strong> Natural radiation, geogenic radon potential, geostatistical analysis, spatial regression model, indoor radon simulation</p>

scholarly journals Mobility of black carbon in drained peatland soils

2007 ◽  
Vol 4 (2) ◽  
pp. 871-891 ◽  
Author(s):  
J. Leifeld ◽  
S. Fenner ◽  
M. Müller
Keyword(s):  
Thermal Oxidation ◽  
Black Carbon ◽  
Water Saturation ◽  
High Mobility ◽  
Organic Soil ◽  
Historical Record ◽  
Scanning Calorimetry ◽  
Different Types ◽  
Ploughing Depth ◽  
Combustion Residues

Abstract. Amount, stability, and distribution of black carbon BC were studied at four sites of a large peatland ("Witzwil") formerly used as a disposal for combustion residues from households to derive BC displacement rates in the profile. Possible artefacts from thermal oxidation with Differential Scanning Calorimetry (DSC) on BC quantification of C-rich deposits were inferred by choosing three sites from a second peatland with no historical record of waste disposal as a reference ("Seebodenalp"). All sites were under grassland at time of sampling, but were partially cropped in the past at Witzwil. Mean BC contents in topsoils of Witzwil ranged from 10.7 to 91.5 (0–30 cm) and from 0.44 to 51.3 (30–140 cm) mg BC g−1 soil, corresponding to BC/OC ratios of 0.04 to 0.3 (topsoil) and 0.02 to 0.18 (deeper soil). At three sites of Seebodenalp, BC was below the detection limit of 0.4 mg g−1 organic soil, indicating negligible formation of BC during thermal oxidation of peat. 13C NMR spectra corroborated the high BC contents at Witzwil. The data refer to a considerable vertical transport of BC given that soils were ploughed not deeper than 30 cm since abandonment of waste application about 50 years ago. The total amount of BC in the Witzwil profiles ranged from 3.2 to 7.5 kg BC m−2, with 21 to 69 percent of it stemming from below the former ploughing depth. Under the premise of negligible rates of BC consumption since abandonment of waste application, minimum BC transport rates in these peats are 0.6 to 1.2 cm a−1. The high mobility of BC might be explained by high macro-pore volumes in combination with occasional water saturation. By means of DSC peak temperatures, different types of BC could be distinguished, with deeper horizons containing BC of higher thermal stability. Application of combustion residues likely involved a mixture of various BC types, of which thermally more stable ones, most likely soots, were preferentially transported downwards.

scholarly journals Information Characteristics for Judicative Documentation of the end the 18th – beginning of the 19th centuries for the Investigation of the History of Everyday Life in the Southern Ukraine

2020 ◽  
Vol 2 (1) ◽  
pp. 149
Author(s):  
Olha M. Posunko
Keyword(s):  
Everyday Life ◽  
Social History ◽  
High Mobility ◽  
Judicial System ◽  
District Court ◽  
Short Period ◽  
Different Types ◽  
History Of ◽  
Information Characteristics ◽  
Southern Ukraine

Social history (the history of everyday life) is a popular trend in modern Ukrainian historical studies. At the same time, it should be noted the studies aimed at the research of everyday life, life, stereotypes, incidents, personal life have an integrated nature. The proposed topic covers a short period of time, which was due to the introduction in the territory of Southern Ukraine of a new judicial system in accordance with the Provisions on Provinces of 1775. Thus, the judicial instances of Yekaterinoslav governorship (1783–1796), later of the Novorossiysk province (1796–1802) are under review. The region is vast, heterogeneous in various indicators. The purpose of the article is to determine the characteristics of different types of forensic documentation, which have the greatest information potential in studying the problems of everyday life of people of the late XVIII – early XIX centuries. The source base are the materials of judicial institutions of the region, ranging from the county level (district courts, magistrates, reprisals) to provincial ones (high district court, high reprisal, provincial magistrate, conscientious court, court chamber and reprisals). The task is to characterize the different types of sources used to disclose the topic; to highlight the scenes that are most clearly presented in these documents. The main results. Characteristics of the following types of court documentation are given: journals (meetings, minutes, decisions); property registries; petitions; interrogations; extracts of cases. As an exception, personal letters are mentioned that were used as evidence at courts. The methods of hermeneutics are of great importance, since due to the lack of other sources, clearly formulated questions and a careful reading of the available documents for the formation of ideas about the era are crucially important. It has been noted that the functioning of the judicial system itself provides facts for the study of the stated topic. According to the approaches of the German sociologist N. Elias in the history of everyday life such category as "working day" is considered. It was at a specified time that the bureaucratic apparatus of the region was emerging with a new bureaucracy and its work schedule, which set a certain rhythm of the life of county and provincial cities. The conclusion is made about the possibility of studying, clarifying individual plots on the history of everyday life of almost all segments of the population (to a lesser extent, peasants). It is noted that criminal cases have a wider social variety. The life of the nobility is characterized primarily by documents of civil proceedings (inheritance division, disputes over land). They demonstrate the household side in the process of distribution and delimitation of land, which Southern Ukraine was experiencing during this period. There are two traditions at the cultural and legal levels: one appeals to the norms of the Lithuanian Statute of 1588 (in counties that have moved away from the territory of the former Hetmanate), the other to Russian imperial legislation. The documents of the judicial instances of the region confirm the fact of quite a high mobility of the population within southern Ukraine; point at the development of modern processes (including their negative manifestations in the form of rising crime); allow us to see the ugly side of the daily life of an individual at that time. Article type: analytical.

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