Download or read book The Effect of Steady Winds on Radon 222 Entry from Soil Into Houses written by and published by . This book was released on 1994 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind affects the radon-222 entry rate from soil into buildings and the resulting indoor concentrations. To investigate this phenomenon, we employ a previously tested three-dimensional numerical model of soil-gas Bow around houses, a commercial computational fluid dynamics code, an established model for determining ventilation rates in the presence of wind, and new wind tunnel results for the ground-surface pressure field caused by wind. These tools and data, applied under steady-state conditions to a prototypical residential building, allow us (1) to determine the complex soil-gas flow patterns that result from the presence of wind-generated ground-surface pressures, (2) to evaluate the effect of these flows on the radon concentration in the soil, and (3) to calculate the effect of wind on the radon entry rate and indoor concentration. For a broad range of soil permeabilities, two wind speeds, and two wind directions, we quantify the"flushing" effect of wind on the radon in the soil surrounding a house, and the consequent sharp decrease in radon entry rates. Experimental measurements of the time-dependent radon concentration in soil gas beneath houses confirm the existence of wind-induced flushing. Comparisons are made to modeling predictions obtained while ignoring the effect of the wind-generated ground-surface pressures. These investigations lead to the conclusion that wind-generated ground-surface pressures play a significant role in determining radon entry rates into residential buildings. [References: 26].
Download or read book Wind induced Contaminant Transport in Near surface Soils with Application to Radon Entry Into Buildings written by William Jowett Riley and published by . This book was released on 1996 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soil and Environmental Analysis written by Keith A. Smith and published by CRC Press. This book was released on 2000-10-12 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Reviews a wide range of methods for soil physical analysis. Considers applications, accuracy, measurement time, and cost of equipment. Provides examples of applications."
Download or read book Wind induced Contaminant Transport in Near surface Soils with Application to Radon Entry Into Buildings written by and published by . This book was released on 1996 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind's interactions with a building's superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport.
Download or read book Handbook of Soil Sciences Two Volume Set written by Pan Ming Huang and published by CRC Press. This book was released on 2018-10-03 with total page 2249 pages. Available in PDF, EPUB and Kindle. Book excerpt: An evolving, living organic/inorganic covering, soil is in dynamic equilibrium with the atmosphere above, the biosphere within, and the geology below. It acts as an anchor for roots, a purveyor of water and nutrients, a residence for a vast community of microorganisms and animals, a sanitizer of the environment, and a source of raw materials for co
Download or read book Sources and Effects of Ionizing Radiation written by and published by . This book was released on 2000 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sources and Effects of Ionizing Radiation Effects written by United Nations. Scientific Committee on the Effects of Atomic Radiation and published by . This book was released on 2000 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Volcanic Geology of S o Miguel Island Azores Archipelago written by J.L. Gaspar and published by Geological Society of London. This book was released on 2015-10-12 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Azores archipelago in the Atlantic Ocean is composed of nine volcanic islands and São Miguel is the largest and most volcanically active. During the past 5000 years several eruptions have taken place on the three active central volcanoes – Sete Cidades, Fogo and Furnas – and in the basaltic fissure systems of Picos and Congro. There is evidence that Furnas was in eruption when the first settlers arrived some time between 1439 and 1443. In the sixteenth and seventeenth centuries there were two explosive sub-Plinian eruptions, Fogo in 1563 and Furnas in 1630. The last eruption on land occurred in the Picos Fissural Volcanic System in 1652, involving the extrusion of lava domes. In 22 chapters, this volume considers the volcanic geology of the island under the headings of geological setting, volcanic history, geological hazards and risk assessment, volcano monitoring and natural resources.
Download or read book Meteorological and Geoastrophysical Abstracts written by and published by . This book was released on 1996 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of the Steady state Transport of Radon from Soil Into Houses with Basements Under Constant Negative Pressure written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical model was developed to simulate this phenomenon, under some specific assumptions. The model simulates: the generation and decay of radon within the soil; its transport throughout the soil due to diffusion and convection induced by the pressure disturbance applied at a crack in the basement; its entrance into the house through the crack; and the resultant indoor radon concentration. The most important assumptions adopted in the model were: a steady-state condition; a house with a basement; a geometrically well-defined crack at the wall-floor joint in the basement; and a constant negative pressure applied at the crack in relation to the outside atmospheric pressure. Two three-dimensional finite-difference computer programs were written to solve the mathematical equations of the model. The first program, called PRESSU, was used to calculate: the pressure distribution within the soil as a result of the applied disturbance pressure at the crack; and the resultant velocity distribution of the soil gas throughout the soil matrix. The second program, called MASTRA, was used to: solve the radon mass-transport equation, and to calculate the concentration distribution of radon in the soil gas within the whole soil; and to calculate the entry rate of radon through the crack into the basement, and the final indoor radon concentration. A parametric sensitivity analysis performed on the model, revealed several features of the mechanisms involved in the transport of radon into the house. 84 refs., 66 figs., 16 tabs.
Download or read book Radon Entry Into Buildings Effects of Atmospheric Pressure Fluctuations and Building Structural Factors written by Allen Latham Robinson and published by . This book was released on 1996 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Indoor Pollution written by E. Willard Miller and published by ABC-CLIO. This book was released on 1998-09-22 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the health hazards of indoor air contaminants and includes information on their sources, the illnesses they can cause, the ways of controlling them, and other related topics.
Download or read book SIMULATION OF THE STEADY STATE TRANSPORT OF RADON FROM SOIL INTO HOUSES WITH BASEMENTS UNDER CONSTANT NEGATIVE PRESSURE written by CELSO DE OLIVEIRA LOUREIRO and published by . This book was released on 1987 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt: within the whole soil; and (2) to calculate the entry rate of radon through the crack into the basement, and the final indoor radon concentration.
Download or read book Radon Entry Into Buildings written by and published by . This book was released on 1996 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.
Download or read book The Natural Radiation Environment VII written by J.P. McLaughlin and published by Elsevier. This book was released on 2005-03-30 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Natural Radiation Environment Symposium (NRE VII), the Seventh in the NRE series, which commenced forty years ago in 1963 at Rice University Texas, was held in Rhodes (Greece) in May 2002. During the intervening four decades the research work presented at these NRE Symposia has contributed to a deeper understanding of natural radiation and in particular of its contribution to human radiation exposures.It is clear from the quality and diversity of the 143 papers in this volume of Radioactivity in the Environment series that the study of the natural radiation environment is an active and continually expanding field of research. The papers in this volume fall into a number of main and topical research areas namely: - the measurement and behaviour of natural radionuclides in the environment - cosmic radiation measurement and dosimetry - the external penetrating radiation field at ground level - TENR (Technologically Enhanced Natural Radiation) and NORM (Naturally Occurring Radioactive Materials) studies - assessment of the health effects of radon - regulatory aspects of natural radiation exposuresIn these papers the results of many new surveys of natural radionuclide levels in the environment and of improved methods of detection are described. While some of the natural radiation sources investigated are unmodified by human activity, many accounts are given here of exposures to natural sources which have been enhanced by technology. Such TENR and NORM exposures are shown to range from activities such as mining, oil and gas exploitation, the use of industrial by-products as building materials, to space travel to name but a few. In several cases quite high doses to some individuals are shown to occur. Accounts are given here of methods to prevent and reduce exposures to such sources.
Download or read book Analytical and Numerical Models for Estimating the Effect of Exhaust Ventilation on Radon Entry in Houses with Basements Or Crawl Spaces written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical exhaust ventilation systems are being installed in newer, energy-efficient houses and their operation can increase the indoor-outdoor pressure differences that drive soil gas and thus radon entry. This thesis presents simplified models for estimating the pressure driven flow of radon into houses with basements or crawl spaces, due to underpressures induced by indoor-outdoor temperature differences, wind, or exhaust ventilation. A two-dimensional finite difference model is presented and used to calculate the pressure field and soil gas flow rate into a basement situated in soil of uniform permeability. A simplified analytical model is compared to the finite difference model with generally very good agreement. Another simplified model is presented for houses with a crawl space. Literature on radon research is also reviewed to show why pressure driven flow of soil gas is considered to be the major source of radon entry in houses with higher-than-average indoor radon concentrations. Comparisons of measured vs. calculated indoor radon concentrations for a house with a basement showed the simplified basement model underpredicting on average by 25%. For a house with a crawl space the simplified crawl space model overpredicted by 23% when the crawl space vents are open and 48% when the crawl space vents are sealed.
Download or read book Pollution Abstracts written by and published by . This book was released on 1996 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indexes material from conference proceedings and hard-to-find documents, in addition to journal articles. Over 1,000 journals are indexed and literature published from 1981 to the present is covered. Topics in pollution and its management are extensively covered from the standpoints of atmosphere, emissions, mathematical models, effects on people and animals, and environmental action. Major areas of coverage include: air pollution, marine pollution, freshwater pollution, sewage and wastewater treatment, waste management, land pollution, toxicology and health, noise, and radiation.
