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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modelling and measurement of radon diffusion through soil application on mine tailings dams.

Speelman, Wilcot John January 2004 (has links)
Masters of Science / Radon (222Rn) has been identified as an important factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventive measures where radon is highly concentrated as in some mines and homes. A study in the diffusion of the inert gas, will give us a better understanding of its possible pathways through soil into the air surrounding mine dumps where the radon releases can become hazardous. Measuring and modelling the radon concentrations in the mine dump soil, can help to deduce the radon flux to identify the problem areas for rehabilitation especially in the cases of gold and uranium mine tailings.
2

Radon (Rn-222) and thoron (Rn-220) emanation fractions from three separate formations of oil field pipe scale

Fruchtnicht, Erich Harold 15 November 2004 (has links)
Over the course of normal oil well operations, pipes used downhole in the oil and petroleum industry tend to accumulate a mineral deposit on their interior, which restricts the flow of oil. This deposit, termed scale, will eventually occlude the interior diameter of the pipe making removal from service and descaling a cost effective option. The pipes are sent to cleaning yards where they remain until descaling can be performed. This storage period can potentially create a health concern not only because of the external radiation exposure but also because of the radon gas emissions, both of which are due to the radioactive minerals contained in the scale. It was believed that the structure of the scale is formed tightly enough to prevent much of the radon from becoming airborne. The goal of this research was to determine the emanation fractions for the rattled scale samples from three formations. A high purity germanium detector was used to measure the activities of the parents and progeny of radon, and electret ion chambers were used to measure the concentration of radon emanated from the scale. The emanation fractions of between 4.9x10-5 and 1.08x10-3 for radon were a factor of approximately 100 smaller than previous research results. For thoron, the fractions were and 5.72x10-8 and 4.92x10-7 for thoron with no previous research to compare. However, information that pertains to the temperature dependence of emanation was included in this research and was not available for previous, similar research. Therefore, differences in the environment (e.g., temperature, humidity, etc.) in which the previous experiments were conducted, as well as differences in the scale formation types used, could account for the discrepancy. In addition, measuring the emanation fractions of the rattled scale was a method of determining whether surface to volume ratio dependence existed. After acquiring the emanation fractions, insufficient evidence of any surface to volume ratio dependence could be found.
3

Radon (Rn-222) and thoron (Rn-220) emanation fractions from three separate formations of oil field pipe scale

Fruchtnicht, Erich Harold 15 November 2004 (has links)
Over the course of normal oil well operations, pipes used downhole in the oil and petroleum industry tend to accumulate a mineral deposit on their interior, which restricts the flow of oil. This deposit, termed scale, will eventually occlude the interior diameter of the pipe making removal from service and descaling a cost effective option. The pipes are sent to cleaning yards where they remain until descaling can be performed. This storage period can potentially create a health concern not only because of the external radiation exposure but also because of the radon gas emissions, both of which are due to the radioactive minerals contained in the scale. It was believed that the structure of the scale is formed tightly enough to prevent much of the radon from becoming airborne. The goal of this research was to determine the emanation fractions for the rattled scale samples from three formations. A high purity germanium detector was used to measure the activities of the parents and progeny of radon, and electret ion chambers were used to measure the concentration of radon emanated from the scale. The emanation fractions of between 4.9x10-5 and 1.08x10-3 for radon were a factor of approximately 100 smaller than previous research results. For thoron, the fractions were and 5.72x10-8 and 4.92x10-7 for thoron with no previous research to compare. However, information that pertains to the temperature dependence of emanation was included in this research and was not available for previous, similar research. Therefore, differences in the environment (e.g., temperature, humidity, etc.) in which the previous experiments were conducted, as well as differences in the scale formation types used, could account for the discrepancy. In addition, measuring the emanation fractions of the rattled scale was a method of determining whether surface to volume ratio dependence existed. After acquiring the emanation fractions, insufficient evidence of any surface to volume ratio dependence could be found.
4

TEMPEST attacks : Using a simple radio receiver / TEMPEST attacker : genom att använda en enkel radio

Karlsson, Jonas January 2003 (has links)
There are no public records that give an idea of how much emanation monitoring is actually taking place. However, there are a few data points that lead us to believe there is a real threat. One of these is that TEMPEST industry is over a billion dollars a year business. Reports like the ”Redefining Security” by Joint Security Commission stated that electronic equipment such as computers, printers, and electronic typewriters give off electromagnetic emanations and that this has long been a concern for various industries. An attacker using the latest and most efficient equipment can monitor and retrieve classified or sensitive information as it is being processed without the user being aware that a loss is occurring. But new information states that the attacker doesn’t need to have access to the latest equipment. This master thesis is based on the three statements below:  It exists a cheap and simple TEMPEST technique that is a security risk.  A downloadable TEMPEST virus is a powerful tool when conducting TEMPEST attacks.  It does not exist a cheap and simple solution that protects common users from TEMPEST attacks. In the experiment I use a program called Tempest_for_eliza and a simple Philips radio receiver. In this thesis I prove that it exist a TEMPEST technique, that is cheap and relatively simple and still is a security risk. I prove this with facts from literature studies and an experiment. Today there is only one way to protect yourself against TEMPEST attacks and that is by metal shielding. This is expensive and home users have the option but not often the resources to finance this type of protection.
5

Estudo e desenvolvimento de metodos analiticos para determinacao da radioatividade natural em aguas

SAMPA, MARIA H. de O. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:29:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:23Z (GMT). No. of bitstreams: 1 00374.pdf: 1851667 bytes, checksum: eb55ab298cfe6ea72073a36c84226d72 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Energia Atomica - IEA
6

Ekologické aspekty vylučování zinku a mědi u skotu / The ecological aspect emanation of zinc and copper in the cattle

JURKOVÁ, Petra January 2009 (has links)
The objective of my diploma thesis was to determine the ecological impact of zinc and copper on the dairy and beef cattle breeding in the South-West Bohemia region at the farms located in the Šumava Protected Landscape Area, at the elevation from 750 m to 1070 m. The research included 4 cattle breeding farms, Posobice and Nemilkov {--} dairy cattle, and Hartmanice, Keple {--} beef cattle. In my thesis, I first evaluate the importance of zinc and copper as important mineral matters and their overall influence of the cattle organism. Furthermore, I evaluate their manifestations when these matters are lacking or in surplus in the organism. The final part of the thesis comprises two areas of findings. The first part focuses on the total intake in feed and mineral additives, the level of their content in blood plasma and their quantity excreted by cattle in the individual dairy and beef cattle breeding farms specified above. The second part researches the release of zinc and copper to the environment.
7

Estudo e desenvolvimento de metodos analiticos para determinacao da radioatividade natural em aguas

SAMPA, MARIA H. de O. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:29:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:23Z (GMT). No. of bitstreams: 1 00374.pdf: 1851667 bytes, checksum: eb55ab298cfe6ea72073a36c84226d72 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Energia Atomica - IEA
8

Avicenna's Doctrine of Emanation and the Sphere of the Heavens

Manere, Brian C 01 January 2023 (has links) (PDF)
Avicenna argues that the celestial spheres each have a soul, termed the motive soul, which is emanated by the first celestial intellect––a body of knowledge which knows itself. Despite outlining the powers of the motive soul, Avicenna does not formally investigate the psychology of the spheres nor their volition. Rather, he presents their volition as a mystery and leaves it to posterity to solve. In an attempt to resolve this mystery, I will argue that it is a direct result of Avicenna having purposefully written a repeated gap into his account of emanation such that there is no clear account of the generation of the material which composes the sphere of the heavens; after clarifying the account of emanation by demonstrating that the sphere has a direct connection to the emanating intellect, I will make the plausible argument that estimation has an intellectual volition insofar as it as it possesses a shared similarity with the practical intellect such that its volition is of the same species of volition: intellectual rather than psychological.
9

The radium distribution in some Swedish soils and its effects on radon emanation

Edsfeldt, Cecilia January 2001 (has links)
The aim of this study has been to clarify how the radiumdistribution in soils affects the radon emanation. Thedistribution of radium, uranium and thorium has been determinedusing sequential extractions. In the study, soils from twodifferent locations were investigated. In the first part the applicability of the sequentialextraction method for determining Ra distribution in differentsoil types was investigated, using a simple sequentialextraction method. Sampled soils were clay, sand and till fromthe vicinity of the Stockholm Esker. The main part of Rnemanating Ra was associated with Fe oxides in the soil. Themethods applied provided information about the radon risk ofthe soil, but, inorder to gain more information on theprocesses governing Ra distribution and radon emanation insoils, a more detailed sequential extraction procedure would bedesirable. The second part consisted of a detailed study of theradionuclide distribution and the geochemistry in a podzolisedglacial till from Kloten in northern Västmanland. A moredetailed sequential extraction procedure was used, and thespecific surface area of samples was measured. Samples weretaken from E, B, and C horizons; radium and thorium wereenriched in the B horizon, whereas uranium had its maximumconcentration in the C horizon. Extractable radium primarilyoccurred in the exchangeable pool, possibly organicallycomplexed, whereas extractable uranium and thorium were mainlyFe oxide bound. Oxide-bound Ra was important only in the Bhorizon. The radon emanation was not correlated with the amountof exchangeable Ra, but instead with the oxide bound Ra.However, the amount of oxide-bound Ra was too small to accountfor all the emanated Rn, thus, exchangeable Ra was interpretedas the main source of emanated Rn. This exchangeable Ra wasmore emanative in the B horizon than in the C horizon. Theexplanation is the larger surface area of the B horizonsamples; the specific surface area appears to be the maingoverning parameter for Rn emanation in this soil. The surfacearea is largely created by the precipitation of amorphous Feoxides, thus, Fe oxides has a significant effect on Rnemanation. Comparing the two studies, the Stockholm samples had thesame amounts of oxide-bound Fe and surface-bound Ra. Still theradon emanation was much smaller for these samples than in theKloten soil. The amount of organic matter in the B horizon ofthe Kloten soil is however, much larger than the organic mattercontent in the Stockholm samples. It is suggested that thelarge Rn emanation in the B horizon of Kloten is caused by thecombined effect of Fe oxides and organic matter. The variability of226Ra distribution in soils was also investigated.The226Ra distribution was determined for samples from60-70 cm and 80-90 cm depth, from three adjacent soil profilesin a podzolic glacial till. Ra distributions, and estimationsof Rn risk based on the Ra distributions, of a single soilprofile, are likely to be representative for a similar area,provided that the samples are taken from a sufficientdepth. KEYWORDS: distribution, emanation, extraction, glacial till,podzol, Ra, radium, radon, Rn, sequential soil, spodosol, Th,thorium, U, uranium, variability
10

The radium distribution in some Swedish soils and its effects on radon emanation

Edsfeldt, Cecilia January 2001 (has links)
<p>The aim of this study has been to clarify how the radiumdistribution in soils affects the radon emanation. Thedistribution of radium, uranium and thorium has been determinedusing sequential extractions. In the study, soils from twodifferent locations were investigated.</p><p>In the first part the applicability of the sequentialextraction method for determining Ra distribution in differentsoil types was investigated, using a simple sequentialextraction method. Sampled soils were clay, sand and till fromthe vicinity of the Stockholm Esker. The main part of Rnemanating Ra was associated with Fe oxides in the soil. Themethods applied provided information about the radon risk ofthe soil, but, inorder to gain more information on theprocesses governing Ra distribution and radon emanation insoils, a more detailed sequential extraction procedure would bedesirable.</p><p>The second part consisted of a detailed study of theradionuclide distribution and the geochemistry in a podzolisedglacial till from Kloten in northern Västmanland. A moredetailed sequential extraction procedure was used, and thespecific surface area of samples was measured. Samples weretaken from E, B, and C horizons; radium and thorium wereenriched in the B horizon, whereas uranium had its maximumconcentration in the C horizon. Extractable radium primarilyoccurred in the exchangeable pool, possibly organicallycomplexed, whereas extractable uranium and thorium were mainlyFe oxide bound. Oxide-bound Ra was important only in the Bhorizon. The radon emanation was not correlated with the amountof exchangeable Ra, but instead with the oxide bound Ra.However, the amount of oxide-bound Ra was too small to accountfor all the emanated Rn, thus, exchangeable Ra was interpretedas the main source of emanated Rn. This exchangeable Ra wasmore emanative in the B horizon than in the C horizon. Theexplanation is the larger surface area of the B horizonsamples; the specific surface area appears to be the maingoverning parameter for Rn emanation in this soil. The surfacearea is largely created by the precipitation of amorphous Feoxides, thus, Fe oxides has a significant effect on Rnemanation.</p><p>Comparing the two studies, the Stockholm samples had thesame amounts of oxide-bound Fe and surface-bound Ra. Still theradon emanation was much smaller for these samples than in theKloten soil. The amount of organic matter in the B horizon ofthe Kloten soil is however, much larger than the organic mattercontent in the Stockholm samples. It is suggested that thelarge Rn emanation in the B horizon of Kloten is caused by thecombined effect of Fe oxides and organic matter.</p><p>The variability of<sup>226</sup>Ra distribution in soils was also investigated.The<sup>226</sup>Ra distribution was determined for samples from60-70 cm and 80-90 cm depth, from three adjacent soil profilesin a podzolic glacial till. Ra distributions, and estimationsof Rn risk based on the Ra distributions, of a single soilprofile, are likely to be representative for a similar area,provided that the samples are taken from a sufficientdepth.</p><p>KEYWORDS: distribution, emanation, extraction, glacial till,podzol, Ra, radium, radon, Rn, sequential soil, spodosol, Th,thorium, U, uranium, variability</p>

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