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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

Comprehensive assessment of PM10 and PM2.5 pollution in the west side of Saudi Arabia using CMAQ and WRF-Chem models

Montealegre, Juan Sebastian 11 1900 (has links)
This work is aimed to study the capabilities of CMAQ and WRF-Chem models for predicting the PM10 and PM2.5 pollution in the west side of Saudi Arabia. To do this fairly, one-month simulations (April, 2021) are done in both models using same initial and boundary conditions, meteorology and anthropogenic emissions. Unique configurations in both models allow to compare differences in the chemical processes and natural emissions estimation of each model. Simulated PM (PM10 and PM2.5) surface concentrations and AOD are compared with available observations to assess models’ performance. Moreover, CMAQ is used to study a real air pollution episode generated by a fire in the Rabigh Electricity Power Station between April 8 and April 11, 2021.
2

Characterization and source apportionment of PM2.5 in the Southeastern United States

Lee, Sangil 07 November 2006 (has links)
Fine particulate matter (PM2.5) affects the environment in a variety of ways, including of human health, visibility impairment, acid deposition, and climate change. As of March, 2006, 47 counties are designated as non-attainment areas in terms of PM2.5 in the southeastern United States. State agencies with PM2.5 non-attainment counties must develop plans that demonstrate how they will achieve attainment status. State agencies also have to address emission sources of visibility impairment and develop strategies to improve visibility. It is essential to understand PM2.5 composition and sources in order to develop effective control strategies to reduce PM2.5. In this thesis, actual prescribed burning emissions were characterized for better estimation of their impacts on air quality. Chemical mass balance (CMB) modeling, a receptor-oriented source apportionment technique, was applied to understand regional characteristics of PM2.5 source impacts in the Southeast. Uncertainty issues in the CMB source apportionment results due to both poor spatial representativeness and measurement errors was addressed for better understanding and estimation of the uncertainties. Possible future research is recommended based on the findings in this thesis.
3

Avaliação do teor de metais em material particulado MP2,5 E MP10 nas cidade de Goiânia - GO e Rio claro - SP empregando a técnica de fluorescência de raios X dispersiva em energia (EDXRF) / Evaluation of the content of metals in particulate matter MP2,5 and MP10 in the city of Goiânia - GO and Rio Claro - SP using the energy dispersive X - ray fluorescence technique

Dourado, Thiago de Araujo [UNESP] 15 September 2016 (has links)
Submitted by THIAGO DE ARAÚJO DOURADO null (tgohand@gmail.com) on 2016-11-08T19:24:16Z No. of bitstreams: 1 DISSERTAÇÃO final final.pdf: 4889486 bytes, checksum: 33b9dbb0208fe5391c73263a61ad83f8 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO null (luizaromanetto@hotmail.com) on 2016-11-10T19:10:30Z (GMT) No. of bitstreams: 1 dourado_ta_me_rcla.pdf: 3118834 bytes, checksum: 4e512369feb953767ccabbc9902676ab (MD5) / Made available in DSpace on 2016-11-10T19:10:30Z (GMT). No. of bitstreams: 1 dourado_ta_me_rcla.pdf: 3118834 bytes, checksum: 4e512369feb953767ccabbc9902676ab (MD5) Previous issue date: 2016-09-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo principal do presente trabalho foi a caracterização química do material particulado em suspenção na atmosfera (MP2,5 e MP10) das regiões metropolitanas de Goiânia (GO) e de Rio Claro (SP), por meio da técnica de fluorescência de raios X por dispersão em energia (EDXRF) com fonte de energia de Luz Síncrotron. A amostragem foi realizada em dois períodos climáticos (inverno-seco e verão-chuvoso), utilizando um amostrador tipo staker, que permite a coleta simultânea de particulado fino (partículas com tamanho de diâmetro menor do que 2,5 µm) e grosso (partículas com diâmetro entre 2,5 e 10 µm). Foram utilizados filtros com 47 mm de diâmetro e com tamanho de poro de 0,4 e 8,0 µm, respectivamente. A quantificação de MP2,5 e MP10 no ar atmosférico foi realizada através de gravimetria. As concentrações de material particulado foram comparadas com os valores indicados por órgãos regulamentadores, nacionais e internacionais (CONAMA13/1990; CETESB/2012; WHO/2015; Directiva Europeia/2008/50). A determinação elementar dos MP2,5 e MP10, compreendeu os seguintes elementos: Si, S, K, Ti, Cr, Mn, Fe, Cu, Zn e Ca. Para a identificação das possíveis fontes de emissão, ou de formação do material particulado, foi calculado o coeficiente de correlação de Pearson associado à análise de agrupamento e a determinação dos fatores de enriquecimento. No geral, as concentrações médias de MP10 e MP2,5 em Goiânia foram maiores que em Rio Claro, assim como os teores elementares. Como esperado, os teores elementares médios foram maiores no inverno que no verão, para as duas localidades. No geral foi observado ao longo das campanhas de amostragem que os elementos majoritários em ambas as frações foram o Si, Fe, Ca e K, característicos de emissões naturais. O tratamento dos dados mostrou que a composição elementar é diferente entre as frações coletadas, exceto as amostras de MP2,5 referentes a Rio Claro. O coeficiente de correlação de Pearson indicou associação dos materiais particulados com metais de origem natural. Para as duas cidades, as análises de agrupamento em conjunto com o cálculo de fator de enriquecimento mostram que a origem de MP10 é associada às emissões naturais, enquanto a origem de MP2,5 é associada às emissões tanto naturais quanto antrópicas. / The main objective of this study was the chemical characterization of the particulate matter in suspension in the atmosphere (PM2.5 and PM10) in the metropolitan areas of Goiânia (GO) and Rio Claro (SP). Sampling was carried out in winter and summer seasons, using a sampler staker type which allows the simultaneous collection of fine particulate (particles smaller diameter size than 2.5 uM) and large (particle diameter between 2.5 and 10 micrometres). Using filters were 47 mm in diameter and 0.4 pore size and 8.0 micrometres respectively. Quantitation of MP10 and PM2.5 in atmospheric air was performed by gravimetry. The particulate matter concentrations were compared to the values indicated by regulators, national and international bodies (CONAMA13 / 1990; CETESB / 2012; WHO / 2015; European Directive / 2008/50). For elemental determination of PM2.5 and PM10 was used to X-ray fluorescence technique by energy dispersive (EDXRF) with power source Synchrotron Light. The elements determined in Rio Claro campaigns and Goiania are Si, S, K, Ti, Cr, Mn, Fe, Cu, Zn and Ca. To determine possible sources of emissions or formation of particulate matter was calculated the correlation coefficient Pearson, associated cluster analysis in conjunction with the enrichment factor calculations. Overall, the average concentrations of PM10 and PM2.5 in Goiania were higher than in Rio Claro, the same occurred for the elementary levels. As expected, the average elementary levels were higher in winter than in summer, for both locations. Overall it was observed over the sampling campaigns that the majority elements in both fractions were Si, Fe, Ca, and K, characteristic of natural emissions. Data analysis showed that the elemental composition is different between the fractions collected, except samples of PM2.5 regarding Rio Claro. The Pearson correlation coefficient indicated association of particulate materials with naturally occurring metals. For both cities, the cluster analysis in conjunction with the enrichment factor of calculation show that the PM10 origin is associated ace natural emissions, while PM2.5 source is associated with emissions both natural and anthropogenic. / CAPES: 36826687801
4

Koldioxidbudget 2021-2045 för Tranemokommun : En granskning av potentiella vägar till en fossilfri kommun

Axengren, Julia January 2020 (has links)
Antropogena utsläpp av koldioxid och andra växthusgaser har orsakat en ökning avden globala genomsnittliga yttemperaturen över förindustriella nivåer. Samhället stårdärför inför en klimatomställning på en global, nationell och lokal nivå. Den globalakoldioxidbudgeten motsvarar den totala mängd antropogena koldioxidutsläpp som ärtillåtet för att hålla sig inom ramen av de uppsatta målen inom Parisavtalet. Studienbryter ner den globala koldioxidbudgeten på lokal nivå för att åskådliggörapotentiella vägar för Tranemo till att bli en fossilfri kommun. Studien bygger därförpå en datainsamling av territoriella och konsumtionsbaserade koldioxidutsläpp inomkommunens geografiska område samt inom kommunens förvaltningsorganisation.Studien analyserar vidare hur den framtida utvecklingen av klimatarbetet påverkarkoldioxidutsläpp med hjälp av scenariotekniker baserat på suveränitetsprincipen.Utsläpp orsakade från industrisektorn, transporter och utrikesflyg motsvarar de trestörsta utsläppskällorna i det geografiska området. Det beskrivna önskvärda scenariot,Best case scenario, budgeterar 602 KT CO2 mellan åren 2021-2045 därutsläppsminskande åtgärder från en av kommunens största industrier är avgörandeför att hålla sig inom ramen av budgeten. Studien visar att om samhället fortsätter attproducera och konsumera i samma takt som tidigare år kommer budgeterade utsläppvara förbrukad vid år 2027. Studien speglar den nationella och globala bilden av industrisektorn som endominerande utsläppskälla. I kontrast till identifierade konsumtionsbaseradeutsläppsminskande åtgärder är industrisektorn är en aktör som skapar en avgörandeeffekt i klimatarbetet för att reducera koldioxidutsläppen. Slutsatser dras attkoldioxidbudgeten som ett politiskt styrande dokument betraktas som ett effektivtstyrmedel om kommunen har större handlingskraft och rådighet över utsläppen somsker. Samverkan mellan offentlig och privat sektor betraktas därför som enframgångsfaktor. Kommunens utmaning för att möjliggöra klimatomställningen är attföra en kraftfull klimatpolitik och vidta åtgärder i ett tidigt skede. Vidare slutsatsersom dras i studien är därför vikten av ett strategiskt utvecklingsarbete för attmöjliggöra klimatomställningen. / Carbon dioxide emissions together with other greenhouse gases emitted byanthropogenic activities have caused an increased global average surface temperatureabove pre-industrial levels. The society is therefore facing a challenge to limit theenvironmental and societal risks associated to a global warming below 2 ° C, with theambition of 1.5 ° C. The global carbon budget determines the total amount ofanthropogenic carbon dioxide emissions that are allowed to likely limit a globalwarming of 2 ° C. By breaking down the global carbon budget at a local level,highlights this study hypothetical ways for the municipality of Tranemo to become afossil free municipality by using scenario techniques according to the principal of“grandfathering”. The study therefor maps out historical territorial and consumptionbasedcarbon dioxide emissions that are caused within the municipality’sgeographical area, and within the municipality’s administrative organization, in orderto further identify and propose climate actions.The study points out that emissions caused by the industrial sector, transportationsector, and international flights generate the greatest impact in the geographical areaof Tranemo. The desirable scenario, Best case scenario, accounts 602 KT CO2 betweenyear 2021-2045 where an emission reduction action from one of the municipality’slargest industries is crucial to stay within the budget. The study illustrates that thebudget will be spent by the year 2027 if the society continues to produce and consumein the same pace as previous years. The industrial sector is a dominant polluter at a national and global level. The studyconfirms that industrial sector is also a dominant emission source at a local level forthe geographical area of Tranemo. Climate actions within the industrial sector aretherefore crucial. The identified consumption-based climate actions are consequentlynegligible in contrast to emissions caused by the industrial sector. The studyconcludes that the carbon budget as a political document is regarded as an effectivetool if the municipality has a greater leverage and resourcefulness of the overallgenerated emissions. Cooperation between public and private actors is considered tobe a factor for success. The study clarifies the importance of strategic developmentwork, and influencing factors connected to it when it comes to transforming oursociety towards a sustainable development. / <p>2020-06-05</p>
5

Estimation of Air Emissions During Production Phase from Active Oil and Gas Wells in the Barnett Shale Basin: 2010-2013

Dohde, Farhan A. 05 1900 (has links)
The Barnett shale basin, the largest onshore gas field in the state of Texas, mainly produces natural gas. The basin’s oil and gas productions have dramatically increased over the past two decades with the enhancement via shale fracturing (fracking) technology. However, recent studies suggest that air emissions from shale fracking have significantly contributed to the growing air pollution problem in North Texas. In this study, air emissions from the Barnett shale basin during the production phase of the oil and gas activities (once the product is collected from the wells) are quantified. Oil and gas production data were acquired from the Texas Railroad Commission for the baseline years of 2010 through 2013. Methodology from prior studies on shale basins approved by the Texas Commission on Environmental Quality was employed in this study and the emission inventories from the production phase sources were quantified. Accordingly, the counties with the most gas operations in the basin, Tarrant, Johnson, Denton and Wise, were found to be the highest emitters of air pollutants. Tarrant County was responsible for the highest emitted NOx (42,566 tons) and CO (17,698 tons) in the basin, while Montague County released the maximum VOC emissions (87,601 tons) during the study period. Amongst the concerned emitted pollutants, VOC was the largest emitted pollutant during the study period (417,804 tons), followed by NOx (126,691 tons) and CO (47,884 tons). Significant Sources of air emissions include: storage tanks, wellhead compressor engines, and pneumatic devices. Storage tanks and pneumatic devices contributed to about 62% and 28% of the total VOC emissions, respectively. Whereas, wellhead compressor engines are primarily responsible for about 97% of the total NOx emissions. Finally, in Tarrant, Wise and Denton counties, the emissions increased during the study period due to increase in the oil and gas production, while Johnson County’s emission contribution declined throughout the study period.
6

Aplicação da antena de Van Veen e Bergervoet na análise de contribuições de fontes de emissão radiada em ambientes eletromagnéticos. / Application of Van Veen and Bergervoet antenna for radiated emission sources contribuition analysis in electromagnetics environments.

Cardia, Daniel Vitor Faria 25 August 2010 (has links)
Este trabalho tem por objetivo apresentar uma análise de desempenho e viabilidade da aplicação da antena de van Veen e Bergervoet na determinação de contribuições de fontes de emissão radiada em ambientes eletromagnéticos, considerando-se a faixa de freqüência de 9 kHz a 30 MHz. Como potencial aplicação resultante deste trabalho está a utilização de resultados experimentais na determinação de fontes equivalentes de emissão radiada, aplicáveis em simulações numéricas e diretamente através de cálculo analítico na determinação de campos eletromagnéticos no espaço. Desta forma, o uso dessas fontes em simuladores de ambientes eletromagnéticos poderá contribuir para diminuir as restrições e dificuldades atuais oriundas da avaliação experimental e teórica de ambientes eletromagnéticos diversos, e daquelas relativas a estudos de compatibilidade eletromagnética de sistemas elétricos e eletrônicos, como sistemas embarcados, etc. / The objective of this work is to present is to present the main theoretical aspects and the evaluation of the van Veen and Bergervoet antenna performance, concerning its application to the determination of equivalent radiated emission sources, for the 9 kHz to 30 MHz frequency range. As a potential application, it is assumed the use of the equivalent sources, obtained based on experimental measurements, directly, on simulations of the resulting electromagnetic environments. The application of this methodology, although considered as a simplified one, may contribute to reduce the current experimental and theoretical restrictions and difficulties regarding the electromagnetic compatibility studies of electrical and electronics systems, like the on-board systems etc.
7

Aplicação da antena de Van Veen e Bergervoet na análise de contribuições de fontes de emissão radiada em ambientes eletromagnéticos. / Application of Van Veen and Bergervoet antenna for radiated emission sources contribuition analysis in electromagnetics environments.

Daniel Vitor Faria Cardia 25 August 2010 (has links)
Este trabalho tem por objetivo apresentar uma análise de desempenho e viabilidade da aplicação da antena de van Veen e Bergervoet na determinação de contribuições de fontes de emissão radiada em ambientes eletromagnéticos, considerando-se a faixa de freqüência de 9 kHz a 30 MHz. Como potencial aplicação resultante deste trabalho está a utilização de resultados experimentais na determinação de fontes equivalentes de emissão radiada, aplicáveis em simulações numéricas e diretamente através de cálculo analítico na determinação de campos eletromagnéticos no espaço. Desta forma, o uso dessas fontes em simuladores de ambientes eletromagnéticos poderá contribuir para diminuir as restrições e dificuldades atuais oriundas da avaliação experimental e teórica de ambientes eletromagnéticos diversos, e daquelas relativas a estudos de compatibilidade eletromagnética de sistemas elétricos e eletrônicos, como sistemas embarcados, etc. / The objective of this work is to present is to present the main theoretical aspects and the evaluation of the van Veen and Bergervoet antenna performance, concerning its application to the determination of equivalent radiated emission sources, for the 9 kHz to 30 MHz frequency range. As a potential application, it is assumed the use of the equivalent sources, obtained based on experimental measurements, directly, on simulations of the resulting electromagnetic environments. The application of this methodology, although considered as a simplified one, may contribute to reduce the current experimental and theoretical restrictions and difficulties regarding the electromagnetic compatibility studies of electrical and electronics systems, like the on-board systems etc.

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