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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.
11

Determinacao de metais pesados e outros elementos em sedimentos da baia de Sepetiba [RJ] por ativacao neutronica

PELLEGATTI, FABIO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:43Z (GMT). No. of bitstreams: 1 06886.pdf: 4121786 bytes, checksum: 130acdd76c4a5005a2a6dab597557aac (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
12

Determinacao de metais pesados e outros elementos em sedimentos da baia de Sepetiba [RJ] por ativacao neutronica

PELLEGATTI, FABIO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:43Z (GMT). No. of bitstreams: 1 06886.pdf: 4121786 bytes, checksum: 130acdd76c4a5005a2a6dab597557aac (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
13

Late Holocene Paleoseismicity along the Northern Oregon Coast

Darienzo, Mark Edward 01 January 1991 (has links)
Marsh paleoseismological studies were conducted in four bays (Necanicum, Nestucca, Siletz, and Yaquina) along the northern Oregon coast and compared with completed studies in two other bays (Netarts and Alsea). Coseismically buried peats were identified in all bays, based on 1) abrupt contacts, decreases in organic content, increases in sand content, increases in beach sand, and changes in diatom assemblages, all from the peat to the overlying sediments, 2) distinct sandy layers and key plant macrofossils, such as Triglochin, above the buried peat, and 3) widespread correlation of the buried peats within the bay. The stratigraphy and the ages and depths of the top six coseismically buried peats were compared between bays. The following similarities were noted: 1) All bays recorded five burial events in the top 2.6 meters within the last 2200 years. 2) Six burial events were recorded in six bays in the top 3.0 meters, except Alsea Bay (3.3 m), and all six events occurred within the last 2600 years except Yaquina (2780 years). 3) The depth to the top of each buried peat in the bays is consistent, falling within discrete ranges, except for the top two events at Yaquina. 4) Distinct sandy layers (tsunami-deposited) are present over the topmost buried peat in all bays except Yaquina and over the 4th in all bays except Yaquina and Nestucca. 5) Distinct tsunami-deposited sandy layers are absent over the third buried peat in Netarts, Nestucca, Siletz, Alsea, and possibly Yaquina, but present at Necanicum. The evidence strongly suggests synchroneity of coseismic events between the Necanicum River and Alsea Bay (a distance of 175 km), with the exception of the 2nd and 6th event. The 6th coseismic event would be synchronous between Alsea and Netarts, a distance of 105 km. The support for synchroneity of the 2nd event is weak. Synchroneity of coseismic burial events on the northern Oregon coast would argue for paleomagnitudes of at least 8.1 Mw, given a minimum rupture width of 50 km and a rupture length of 105 km. The paleomagnitudes were determined using the moment magnitude equation, Mw = 2/3 IOg10 Mo - 10.7 where Mo = shear modulus x rupture area x seismic slip. The seismic slip is estimated from a minimum recurrence interval of 300 years and a minimum convergence rate of 3.5 cm/yr.Marsh paleoseismological studies were conducted in four bays (Necanicum, Nestucca, Siletz, and Yaquina) along the northern Oregon coast and compared with completed studies in two other bays (Netarts and Alsea). Coseismically buried peats were identified in all bays, based on 1) abrupt contacts, decreases in organic content, increases in sand content, increases in beach sand, and changes in diatom assemblages, all from the peat to the overlying sediments, 2) distinct sandy layers and key plant macrofossils, such as Triglochin, above the buried peat, and 3) widespread correlation of the buried peats within the bay. The stratigraphy and the ages and depths of the top six coseismically buried peats were compared between bays. The following similarities were noted: 1) All bays recorded five burial events in the top 2.6 meters within the last 2200 years. 2) Six burial events were recorded in six bays in the top 3.0 meters, except Alsea Bay (3.3 m), and all six events occurred within the last 2600 years except Yaquina (2780 years). 3) The depth to the top of each buried peat in the bays is consistent, falling within discrete ranges, except for the top two events at Yaquina. 4) Distinct sandy layers (tsunami-deposited) are present over the topmost buried peat in all bays except Yaquina and over the 4th in all bays except Yaquina and Nestucca. 5) Distinct tsunami-deposited sandy layers are absent over the third buried peat in Netarts, Nestucca, Siletz, Alsea, and possibly Yaquina, but present at Necanicum. The evidence strongly suggests synchroneity of coseismic events between the Necanicum River and Alsea Bay (a distance of 175 km), with the exception of the 2nd and 6th event. The 6th coseismic event would be synchronous between Alsea and Netarts, a distance of 105 km. The support for synchroneity of the 2nd event is weak. Synchroneity of coseismic burial events on the northern Oregon coast would argue for paleomagnitudes of at least 8.1 Mw, given a minimum rupture width of 50 km and a rupture length of 105 km. The paleomagnitudes were determined using the moment magnitude equation, Mw = 2/3 IOg10 Mo - 10.7 where Mo = shear modulus x rupture area x seismic slip. The seismic slip is estimated from a minimum recurrence interval of 300 years and a minimum convergence rate of 3.5 cm/yr.
14

Observed and simulated temporal and spatial variations of gap outflow region

Cherrett, Robin Corey. 09 1900 (has links)
This study focuses on understanding the development of gap outflow and the air-sea interaction processes during the 26 February 2004 Tehuano event over the Gulf of Tehuantepec, Mexico. The Navy's Coupled Ocean Atmospheric Mesoscale Prediction System (COAMPS) was used to simulate the gap wind event and was compared to satellite, scatterometer, and coincident in situ aircraft and dropsondes measurements collected during the Gulf of Tehuantepec Experiment (GOTEX). Comparisons between model results and the observations suggest that COAMPS performed the best in simulating the outflow jet within 200 km offshore, although the simulated surface fluxes deviated significantly from the observations. This is the region where the dominant dynamical forcing arises from the coastal topography. Larger discrepancies were found in model result further away from the coast, especially to the south and southeast of the gulf where the air-sea exchange became increasingly important. Detailed inter-comparison between COAMPS and the aircraft measurements at 40 m also shows the strong spatial and temporal variations of boundary layer thermodynamics and turbulence, which require improved characterization of the sea surface temperature, upper air conditions, and initial conditions for COAMPS. The results also point to the needs for improved surface flux parameterization, particularly in high wind conditions.
15

Electronic Warfare (EW) historical perspectives and its relationship to Information Operations (IO)-considerations for Turkey

Kucukozyigit, Ali Can. 09 1900 (has links)
The purpose of this thesis is the exploration of the relationship and interaction between Electronic Warfare (EW) and Information Operations (IO) core, supporting and related competencies. Understanding the definitions of information and its value, information superiority, and the decision making cycle provides the foundation for the thesis. Investigation of the historical transformation of EW from the U.S. Civil War to the First Gulf War, and also examining how the concept of IO has developed and evolved contributes to this study by helping to comprehend the modern day interaction between EW and each IO competency separately. This interaction is constructed upon the guidance and standards provided by the latest U.S. Joint Chiefs of Staff Publication Joint Publication 3-13 Information Operations. This study concludes that the relationship between EW and IO is increasingly interactive and consists of two aspects: limiting and interfering, and reinforcing and supporting. Also, the relationship between EW and each IO competency is not consistent between the core and supporting competencies. In addition to these conclusions, this study expresses some considerations for EW and IO applications with respect to the unique environment and requirements of the Turkish Republic.
16

Abordagem bayesiana da isoterma de langmuir

CARVALHO, Diailison Teixeira de 12 February 2016 (has links)
Os metais-traço são contaminantes altamente tóxicos presentes sobretudo no meio aquático. Uma técnica eficiente para remoção desses metais-traço é o processo de adsorção. Em estudos laboratoriais relacionados à adsorção há a geração de materiais contaminados, o que implica em riscos socioambientais, além de custos adicionais associados ao tratamento e descarte apropriado dos resíduos tóxicos gerados. Diante disso, há uma limitação prática na quantidade de amostra disponível. O processo de adsorção pode ser descrito por isotermas de adsorção, das quais a mais conhecida é a isoterma de Langmuir. Esta isoterma apresenta o parâmetro k, relacionado à energia de adsorção, e o parâmetro M, que indica a capacidade máxima de adsorção do metal em uma matriz adsorvente. A estimação destes parâmetros geralmente baseia-se em métodos assintóticos, portanto para tamanhos de amostras pequenas as estimativas tendem a apresentar baixa precisão e acurácia. Desse modo, há um impasse em como obterem-se estimativas precisas e acuradas e ao mesmo tempo utilizar-se de amostras de tamanho reduzido. Objetivando superar este problema, foi estudado neste trabalho, a aplicação da inferência bayesiana no ajuste da isoterma de Langmuir considerando prioris informativas e não informativas. Realizou-se então um estudo de simulação de dados com tamanhos amostrais de 5, 6, 7, 9, 12, 15, 20, 25 e 30, analisados em dois cenários com diferentes valores de M e k. Para avaliar a precisão foram utilizados o erro quadrático médio e a amplitude do intervalo HPD ao nível de 95% de credibilidade, para a acurácia o viés médio relativo absoluto. Amostras das distribuições marginais a posteriori dos parâmetros foram obtidas pelo amostrador de Gibbs. As inferências foram realizadas e os resultados indicaram que as estimativas obtidas com uso das prioris informativas apresentaram maiores precisão e acurácia mesmo em tamanhos amostrais inferiores. Posteriormente ajustou-se a isoterma sobre dados experimentais de adsorção de chumbo Pb2+ em cascas de laranja, considerando as prioris propostas e os resultados obtidos corroboraram com o estudo de simulação. Assim, a metodologia bayesiana mostrou-se eficiente para a estimação dos parâmetros da isoterma de Langmuir e o uso de prioris informativas permitiu a obtenção de estimativas com precisão e acurácia satisfatórias para tamanhos amostrais relativamente inferiores, o que permite contornar a limitação prática da quantidade de amostra disponível em estudos reais de adsorção. / The trace metals are highly toxic contaminants particularly in the aquatic environment. The adsorption process is an efficient technique for removing these trace metals. There is a generation of contaminated materials in studies laboratory related to adsorption, it this implies social and environmental risks and additional costs associated with treatment and proper disposal of toxic waste. This fact brings a practical limitation on the amount of sample to be used. The adsorption process can be described by functions called adsorption isotherms. The Langmuir isotherm is one of the most used. This isotherm shows the parameter k related to the energy of adsorption, and the M parameter which indicates the maximum capacity metal adsorption. The parameter estimation is generally based on asymptotic methods therefore for small sample sizes estimates tend to have low precision and accuracy. Thus, there is a difficulty in obtaining precise and accurate estimates at the same time be used for small sample size. Aiming to overcome this problem has been studied in this work, the application of Bayesian inference in fitting isotherm Langmuir considering informative and uninformative priors. Then carried out a study of data simulation with sample sizes of 5, 6, 7, 9, 12, 15, 20, 25 and 30, they were discussed in two scenarios considering different values of M and k. For the evaluation of the precision was used the mean square error and the length of a 95% HPD credible intervals, for to evaluate the accuracy was used the mean bias relative absolute. The samples of the marginal posterior distributions the parameters were obtained by the Gibbs sampler. The inferences were made. The results indicated that the estimates obtained with use of informative priors presented greater precision and accuracy even at lower sample sizes. Subsequently the isotherm was adjusted on experimental data of adsorption lead (Pb2+) in orange peel considering the priors proposals and the results corroborate whith the results obtained in the simulation study. Thus, the methodology bayesian was efficient for the estimation of isotherm parameters of Langmuir and the use of informative priors, it allowed bypass practical limitation on the amount of sample available in real adsorption studies. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
17

Metodologia para avaliar a poluição na baía de Paracas. / Methodology to measure the pollution in the Paracas Bay (Peru).

Carnero Chávez, Dewar Taylor 17 June 2009 (has links)
O objetivo deste trabalho é propor metodologias que permitam estimar e avaliar a dimensão dos impactos no meio ambiente de baías com porto, tendo com área referencial a baía de Paracas no Peru. Nos últimos 40 anos, a baía de Paracas tem sido submetida a uma imensa pressão ambiental em função das descargas das diversas atividades antrópicas desenvolvidas na região e que colocam em risco o ecossistema da única reserva ecológica costeira da costa leste do Pacifico Sul. A degradação nessa baía tem-se visto intensificada pela explosão demográfica, necessidade de crescimento econômico regional e carência de metodologias de desenvolvimento sustentável. É precisamente esta lacuna que motivou o desenvolvimento desta pesquisa, a qual adotou os princípios estabelecidos na norma ISO-14001:2004, e tem como intuito servir de subsidio aos gestores políticos para a implementação de políticas econômicas, sociais e ambientalmente corretas. A pesquisa iniciou-se fazendo uma abordagem panorâmica da política ambiental, focalizando sua aplicação na América Latina e, especificamente, no Peru. Primeiramente foi realizada uma pesquisa exploratória buscando informações técnicas, ambientais e jurídicas utilizadas pelos órgãos intervenientes na gestão ambiental. Seguindo a lógica da norma ISO-14001 foi realizado o diagnóstico ambiental da área de influência da baía, fazendo uso de dados georeferenciados obtidos pelo programa Google Earth; nesta foram identificadas as principais atividades que despejam seus efluentes na baía e identificados os principais aspectos e impactos ambientais, os quais foram caracterizados segundo a nomenclatura do CONAMA, e propostas medidas mitigadoras junto à legislação peruana aplicável. Ainda o trabalho foi complementado com um estudo sobre a circulação dos poluentes na baía, implementado através de modelagem numérica aplicada na equação advecção-dispersão (lei de Fick) e simulados no software Matlab. Finalmente, com base dos dados obtidos em campo, foi feita a caracterização da qualidade da água na baía segundo os parâmetros estabelecidos pelo IQA da National Sanitation Foundation. De acordo com os resultados, conclui-se que a baía está sendo muito prejudicada pelos despejos sólidos, líquidos e gasosos; os níveis obtidos ultrapassam os limites permissíveis da Lei Geral das Águas para cada área estudada; o elevado nível e contaminação na baía tem relação direta com as doenças na região (doenças respiratórias e gastrointestinais); a característica física da baía tem influência direta na recuperação desta, e seu processo de autodepuração está comprometido. Diante disso, como contribuição, este trabalho preocupou-se em propor alguns planos e programas que visem o desenvolvimento sustentável das atividades antrópicas e respeito ao meio ambiente. / The aim of this work is to propose methodologies that allow us to estimate and evaluate the dimension of the impacts on the environment of bays with harbour, having Paracas Bay in Peru as an area of reference. Over the last forty years, Paracas Bay has been submitted to a huge environmental pressure as a result of discharges from numerous human activities developed in the region, which threatens the ecosystem of the only ecological reservation on the east coast of the South Pacific Ocean. The environmental degradation on this bay has been intensified by the demographic explosion, the necessity of a regional economic growth and the deficiency of methodologies of sustainable development. This gap is precisely what motivated the development of this research which adopted the principles established by the ISO- 14001:2004 standard and it is aimed at aiding political managers for the implementation of correct environmental, social and economic policies. The research started with a panoramic approach of the environmental policy focusing on its application in Latin America, specifically in Peru. Firstly, an exploratory research was conducted, looking for judicial, environmental and technical information used by the intervening agencies in the environmental management. Following the reasoning of the ISO-14001 standard, an environmental examination of the bay\'s catchment area was carried out, making use of georeferencing data obtained by Google Earth. The main activities that pour their effluents on the bay were identified in this area, as well as the major aspects and environmental impacts which were characterised according to CONAMA standard, and mitigating measures were proposed by the applicable Peruvian legislation. This work was also supported by the examination of the flux of pollutants on the bay, enhanced through the numerical modelling applied in the advection-dispersion equation (Fick\'s Law) and simulated by the MATLAB software. Finally, the water quality\'s characterisation was based on the data obtained in the field, in conformity with the parameters established by the National Sanitation Foundation Water Quality Index (NSFWQI). According to the results, we can draw the conclusion that the bay is being heavily damaged by discharges of gas, liquid and solid materials. The level of contaminants exceed the permissible limits of the \" General Water Law\" for each analysed area. The high level of contamination of this bay is directly related with some local diseases (gastrointestinal and respiratory diseases). The bay\'s geographic feature has a direct influence on its recovery, although the self-depuration process of the water body is highly compromised. In view of that, as a contribution, this work was devoted to proposing some plans and programmes which aim at the sustainable development of human activities and the respect for the environment.
18

Waqf-institution och Gazi Husrev bays bibliotek i Bosnien-Hercegovina / Waqf-institution and Gazi Husrev bays library in Bosnia and Herzegovina

Hadzic, Sabahudin January 2006 (has links)
This thesis is of an historical nature and deals with two institutions in Bosnia and Hercegovina: waqf and the Library of Gazi Husrev bay. These institutions are placed in a societal context which makes it easier to understand their origins, development and decline. The purpose of this thesis is to describe and analyze the history of the Library of Gazi Husrev bay and its specific characteristics as well as analyze the institution of waqf in a societal context. The questions posed by this thesis are: What is waqf and its meaning? What are its benevolent as well as hostile periods? How did the Library of Gazi Husrev bay and its mission develop? The thesis is limited to waqf in its societal context. The method used consists of a qualitative literature study with source criticism and hermeneutics as methods of interpretation. The study shows that waqf is an important societal institution which has roots dating back to early Islamic history, that waqf had/has great importance in the education of Bosnians and the development of society in general, and that it was/is a widespread phenomenon in Bosnia. The thesis also shows that waqf experienced a number of hostile and benevolent periods as well as a neutral one. When it comes to the Library of Gazi Husrev bay, the thesis shows the library’s arduous history, its mission as well as its role in the preservation of Bosnia’s cultural heritage. / Uppsatsnivå: D
19

Interactions between macroalgae and the sediment microbial community : nutrient cycling within shallow coastal bays /

Hardison, Amber Kay, January 2009 (has links) (PDF)
Thesis (Ph. D.)--College of William and Mary. / Vita. Includes bibliographical references. Also available online.
20

Μοντελοποίηση και συμπερασμός υπό συνθήκες αβεβαιότητας σε διαλογικά και άλλα συστήματα φυσικής γλώσσας με τεχνικές δικτύων Bayes

Μαραγκουδάκης, Εμμανουήλ Σ. 05 July 2010 (has links)
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