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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

Kietųjų dalelių pernašos tyrimai atmosferoje SILAM modeliu / Particulate matter transport in the atmosphere research using silam model

Mažeikis, Adomas 09 July 2011 (has links)
Šiame darbe atliekamas kietųjų dalelių dispersijos modeliavimas SILAM modeliu pernašos atmosferoje tyrimo tikslais, pateikiami modelio rezultatai, išvados. Lietuvoje yra sąlygos efektyviam modelio darbui bei poreikis modeliuoti ir prognozuoti atmosferos teršalų sklidimą, todėl šio darbo rezultatas ir darbo metu sukurta modelio nustatymo metodika galėtų būti plačiai naudojami praktikoje. Kol kas nėra gausios informacijos apie atmosferos taršos modeliavimą Lietuvos teritorijoje. Atliekami tik matavimai ir regioniniu bei valstybės mastu naudojami kaimyninių valstybių modeliavimo duomenys, o atskiros savivaldybės teršalų sklaidą atmosferoje modeliuoja mikro masto modeliais. Pagrindinis darbo tikslas: ištirti pagrindines kietųjų dalelių pernašos Lietuvos teritorijoje savybes naudojant SILAM modelį, parengtą kietųjų dalelių dispersijos modeliavimui ir prognozavimui Lietuvos teritorijoje bei kuo naujesnius ir kuo gausesnius duomenis iš Lietuvos institucijų (pavyzdžiui Lietuvos hidrometeorologijos tarnybos, Aplinkos ministerijos ir t.t.). Gauti rezultatai, išvados: 1. Pagal atliktų modeliavimų rezultatus matyti, kad pagrindinė kietųjų dalelių taršos dalis laikosi priežeminiuose troposferos sluoksniuose ir pernešama netoli (šis braižas verčia manyti, kad tai stambiosios frakcijos). Tuo tarpu į aukštesnius sluoksnius patenka keletą ir net keletą dešimčių kartų mažesnė kietųjų dalelių dalis, bet jos pernešamos toliau. 2. Pagal gautus duomenis galima teigti, kad modeliuojamuoju... [toliau žr. visą tekstą] / The main purpose of this diploma thesis “Particulate matter transport in the atmosphere research using SILAM model” (written by Adomas Mažeikis) is to use SILAM model to research the transport of local Particulate matter pollutants and those from neighboring countries too. Emission data was prepared by interpolating EMEP and Statistical Department provided data sets. Meteorological data was taken from Lithuanian HydroMeteorological Service HIRLAM installation. The setup of model was prepared and test runs were made (one of them is simulating fire in oil refinery "Mažeikių nafta"). The results of this thesis are large arrays of past (2007 October - 2008 April) PM10 dispersion data. Grads package was used to perform the analysis of data and these are the conclusions made after the analysis was finished: 1. SILAM model is accurate enough for researching country wide PM10 transport analysis. 2. Each and every model run needs individual setup for best performance. 3. SILAM is not user friendly application and there is a lack of documentation (User guide, Operational instructions and model technical descriptions are available but it does not describe the setup of model in details). 4. Users of SILAM should check model run logs. There is plenty of useful data in there though the format is not very usable. 5. Performed analysis of model run results shows that the biggest part of PM10 aerosol is in the lower levels of the troposphere and that part is transported up to 100km (this can... [to full text]
2

Zur Grobabschätzung von Schwebstaubkonzentrationen ausSichtweitenbeobachtungen: Zur Grobabschätzung von Schwebstaubkonzentrationen ausSichtweitenbeobachtungen

Hoyningen-Huene, Wolfgang von 08 November 2016 (has links)
Ein Weg zur Abschätzung von Schwebstaubkonzentrationen aus Sichtweitenbeobachtungen in einer belasteten Atmosphäre auf der Basis der Sichtweitentheorie nach Koschmieder, 1925 unter Berücksichtigung der Feuchtigkeit wird beschrieben. / An approach for the estimation of concentrations of particulate matter in a polluted atmosphere has been described basing on the view range by the Koschmieder formula under consideration of the relative humidity.
3

Compostos organicos volateis na atmosfera urbana da região metropolitana de São Paulo / Volatile organic compounds in urban atmosphere of metropolitan area of São Paulo

Albuquerque, Edler Lins de 14 May 2007 (has links)
Orientador: Edson Tomaz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T00:00:54Z (GMT). No. of bitstreams: 1 Albuquerque_EdlerLinsde_D.pdf: 18576988 bytes, checksum: f5a08b5bbd306ca352ba5e96455e69d8 (MD5) Previous issue date: 2007 / Resumo: Realizou-se um estudo experimental dos Compostos Orgânicos Voláteis (COV) encontrados na atmosfera urbana da Região Metropolitana de São Paulo (RMSP). O objetivo principal foi medir as concentrações de COV, procurando identificar, por meio de análises multivariadas, relações entre estas concentrações, parâmetros meteorológicos e concentrações de outros poluentes. Métodos de amostragem passiva e ativa foram empregados utilizando tubos de aço contendo o sólido adsorvente TENAX TA. A quantificação das amostras ocorreu por dessorção térmica automática e cromatografia gasosa com detecção por ionização em chama. Analisou-se COV selecionados, incluindo alcanos, cicloalcanos e compostos aromáticos. Diversos aspectos foram investigados em estudos específicos: emissão veicular, variabilidade diária das concentrações, emprego da amostragem passiva, potencial para formar ozônio etc. As concentrações registradas em cada campanha variaram bastante em função de aspectos associados a características locais das fontes de emissão, horários de coleta, fatores sazonais e meteorológicos. Verificou-se que tolueno, m,p-xilenos, n-hexano, etilbenzeno e 1,2,4-trimetilbenzeno foram os COV encontrados em maiores concentrações na maioria dos estudos realizados, estando os mesmos entre os mais emitidos pelos veículos e entre aqueles com maior potencial para formar ozônio. No local monitorado, o perfil de variação temporal das concentrações de COV foi diferente em função de condições sazonais e/ou meteorológicas. A validação da amostragem passiva possibilitou estimar taxas de amostragem dos COV, as primeiras da literatura científica para vários compostos e as primeiras obtidas numa atmosfera urbana de cidades brasileiras. Isto viabilizou a realização de um monitoramento passivo simultâneo em oito locais diferentes, permitindo verificar as vantagens deste tipo de coleta. Acredita-se que os resultados desta pesquisa possam auxiliar na criação de planos de monitoramento para os COV / Abstract: The aim of this research was an experimental study of Volatile Organic Compounds (VOCs) found in the urban atmosphere of Metropolitan Area of São Paulo (MASP). The main purpose was to measure atmospheric concentrations of VOCs. Multivariate analyses were used to identify relationships among VOCs concentration, meteorological parameters and concentrations of other pollutants. Passive and active sampling methods were applied. Steel tubes packed with adsorbent TENAX TA were employed. The samples were quantified by automatic thermal desorption and gas chromatography with flame ionization detection. Selected VOCs were analyzed, including alkanes, cycloalkanes and aromatic compounds. Many topics related to VOCs were investigated: vehicular emissions, time variation of concentrations, employ of passive sampling, potential of ozone formation etc. For this, some specific studies were conducted. VOCs concentration vary a lot in each campaign in function of aspects associated to local characteristics of emission sources, sampling time, season and meteorological factors. In most of performed studies toluene, m,p-xylenes, n-hexane, ethylbenzene and 1,2,4-trimethylbenzene were VOCs found in higher concentrations. Additionally, such compounds were also found among VOCs with higher vehicular emission factors and higher ozone forming potentials. At the monitoring site, VOCs concentrations have shown distinct profile of time variation for different seasonal and meteorological conditions. VOCs uptake rates were estimated from the validation of passive sampling process. These uptake rates were the first found for many VOCs and the first found in an urban atmosphere of Brazilian cities. This fact became possible to perform a simultaneous passive monitorization campaign in eight different sites at MASP, verifying the advantages of this type of sampling strategy. It is believed that the results of this research may aid in the creation of monitoring programs for VOCs / Doutorado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

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