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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.
131

Anaerobic Treatment Of Opium Alkaloid Wastewater And Effect Of Gamma-rays On Anaerobic Treatment

Ozdemir, Recep Tugrul 01 October 2006 (has links) (PDF)
In this study, anaerobic treatability of opium alkaloid wastewater and the effect of radiation pretreatment (gamma-rays) on anaerobic treatability were investigated. Biochemical Methane Potential (BMP) assay was performed with alkaloid wastewater having initial COD values of 2400, 6000 and 9600 mg/L with and without basal medium (BM). The highest anaerobic treatment efficiency of 77% was obtained in the BMP reactor containing alkaloid wastewater with initial COD of 9600 mg/L and BM. Co-substrate use was investigated by using BMP assay. Alkaloid wastewater having initial COD concentrations of 9000, 13000 and 18000 mg/L were used with glucose, acetate and glucose-acetate as co-substrates. Results revealed that co-substrate use did not improve alkaloid removal efficiency significantly but it abrogated the acclimation period of anaerobic bacteria to alkaloid wastewater. Continuous reactor experiments were carried out in Upflow Anaerobic Sludge Blanket (UASB) reactors. Highest overall efficiencies (above 80%) were obtained in the reactor fed with co-substrate (R2) for all initial COD concentrations. Up to 78% removal efficiency was obtained in R1 (fed with alkaloid wastewater only) at initial COD concentration of 19 g/L. Effect of radiation was sought by using BMP assay with two initial COD concentrations of 14 and 25 g/L, and two radiation doses 40 and 140 kGy. At 14 g/L COD, there was no effect of radiation on gas production for both doses. However at initial COD of 25 g/L, reactors containing wastewater dosed with 140 and 40 kGy produced gas with higher rates above certain point with respect to raw wastewater.
132

A Decision Support Tool For Conceptual Site Model Development At Contaminated Sites

Buyuker, Beril 01 September 2009 (has links) (PDF)
A conceptual site model (CSM) is simply a description of the environmental conditions at a contaminated site and surrounding area, which provides all interested parties with a vision of the site. CSM mainly identifies the source-pathway&amp / #8208 / receptor linkage to guide for effective site characterization, risk assessment and remedial investigations. Development of CSM is complicated because it is &lsquo / case specific&rsquo / and there is no single route to follow during decision making concerning the contaminated site. Moreover, type and extent of information needed varies according to size and level of contamination and site heterogeneity. The objective of this study is to develop a decision support tool that guides the site assessors during identification of possible decision routes that can be encountered / the procedure to be followed / and the information and data to be collected at each stage. This tool also introduces interactions between CSM andsampling strategies designed for various purposes. Developed decision support tool adapts to each specific contaminated site. Furthermore, a detailed review of sampling strategies is presented as a guidance for site assessors. The decision support tool is equipped with standardized tools used for CSM development, i.e. information/data collection forms, illustrative tools and exposure pathway diagram. Information on site, geology, hydrogeology, contamination source, contaminants and receptors is collected via CSM form. Illustrative tools may vary from very simple site sketches to very complex 3D drawings depending on the needs of the specific contamination cases. Exposure pathway diagram (EPD) is used to identify all transport mechanisms and potential exposure pathways. EPD is embedded into a user&amp / #8208 / friendly decision assistance tool based on Microsoft Excel and Visual Basic for Applications. The applicability and utility of the decision support tool was tested using two case studies. Case study applications indicated that the developed methodology satisfies the objectives aimed in this study.
133

Development Of A Fuzzy Rule Based Remedial Priority Ranking System For Contaminated Sites

Polat, Sener 01 December 2009 (has links) (PDF)
Evaluation of contaminated sites based on human health and environmental hazards is an essential task for the proper management of the contaminated sites. A large number of contaminated sites have been waiting for remediation all over the World. However, contaminated site remediation is generally a difficult, time consuming and very expensive process. Ranking systems for contaminated sites are useful tools to determine the remedial priority and to manage the available remediation budget in the most efficient way before the costly remedial actions are taken. To be able to have a reliable ranking result, accurate and sufficient amount of data on the nature of contamination and site characteristics are needed, which are usually not available at the early identification phases of contaminated sites, and the available data is mostly limited and vague in nature. If the available data are inaccurate or vague, the corresponding remedial ranking results can be questionable, as well. Most of the current ranking methodologies overlook the vagueness in the parameter values. The main objective of this study is to develop a remedial priority ranking system for contaminated sites by taking vagueness in parameter values into account. Within this context, development of the new Remedial Priority Ranking System, RPRS, aims to define and evaluate the current and possible environmental risks by using sufficiently comprehensive readily available parameters describing the fate and transport of contaminants in the environment and considering vagueness in those parameter values. The consideration of vagueness in parameter values was included in remedial prioritization of contaminated sites by means of fuzzy set theory. A fuzzy expert system was built up for the evaluation of contaminated sites and it was developed in Microsoft Office Excel 2007 platform, with the intention of making the evaluation fast and user friendly. Hypothetical and real case study applications are presented to test ease of use and validity of the results of the developed methodology. Results of case study applications revealed that the developed RPRS can serve as an alternative method for remedial priority ranking of contaminated sites.
134

Προσδιορισμός εκπομπών αέριων ρύπων στα αστικά κέντρα της Ελλάδας

Δημοπούλου, Μαρία 23 October 2007 (has links)
Στα πλαίσια της εργασίας θα ασχοληθούμε με την μεθοδολογία υπολογισμού των ρυθμών εκπομπής αέριων ρύπων στα αστικά κέντρα της Ελλάδας. Οι πήγες της ατμοσφαιρικής ρύπανσης διακρίνονται σε σημειακές, επιφανειακές, ανθρωπογενείς και φυσικές. Στο πρώτο στάδιο θα γίνει καταγραφή και κατηγοριοποίηση των διαφόρων πηγών για τις Ελληνικές συνθήκες με βάση την διεθνή βιβλιογραφία. Οι μέθοδοι προσδιορισμού των ρυθμών εκπομπής θα διερευνηθούν. Συνήθως οι υπολογισμοί απαιτούν δυο ειδών παραμέτρους: την ένταση μιας δραστηριότητας (π.χ πόσα χιλιόμετρα διανύονται σε μια περιοχή από τα αυτοκίνητα μιας ορισμένης κατηγορίας σε μια περιοχή), και τον ρυθμό εκπομπής ανά μονάδα της δραστηριότητας (π.χ εκπομπές οξειδίων του αζώτου ανά χιλιόμετρο). Ανάλογα με την πηγή οι μέθοδοι μπορεί να είναι πιο πολύπλοκοι ή να απαιτούν την γνώση μεταβλητών που δεν είναι εύκολο να βρεθούν. Οι διαφορετικές προσεγγίσεις θα συγκριθούν τόσο με βάση την ακρίβεια τους όσο και με την δυνατότητα εφαρμογής τους στην Ελλάδα. Το τελικό αποτέλεσμα της εργασίας θα είναι μια αναλυτική μεθοδολογία υπολογισμού των εκπομπών ρύπων σε μια Ελληνική πόλη και συγκεκριμένα στην πόλη της Πάτρας, όπου θα μελετηθεί η εκπομπή αέριων ρύπων από τα επιβατικά πλοία τα οποία χρησιμοποιούν το λιμάνι της Πάτρας. Η παρούσα εργασία θα στοχεύσει στον προσδιορισμό της συγκέντρωσης αέριων ρύπων (σωματιδίων PM) στο αστικό κέντρο της Πάτρας, λαμβάνοντας ως πηγή ρύπων τα επιβατικά πλοία που παραμένουν στο Λιμάνι της Πάτρας. Η συγκέντρωση των αέριων ρύπων τέλος, θα υπολογισθεί με χρήση της Gaussian Plume Formula [JS Seinfeld and SN Pandis: “Atmospheric Chemistry and Physics: From Air Pollution to Climate Change”, 2nd edition, John Willey & Sons, INC]. / -
135

Sustainability in Retailing – Environmental Effects of Transport Processes, Shopping Trips and Related Consumer Behaviour

Wiese, Anne 16 August 2013 (has links)
No description available.
136

Dulkių ir triukšmo taršos tyrimai kaimo kelių aplinkoje / Research of Dust and Noise Pollution in the Environment of Rural Roads

Adomaitis, Gedas 28 May 2012 (has links)
Šio darbo tikslas – kompleksiškai ištirti dulkėtumą ir triukšmą kaimo gyvenviečių žvyruotų kelių aplinkoje ir natūralių želdinių įtaką taršos lygiui. Atliktais tyrimais nustatyta, kad dulkių koncentracija kelyje su žvyro danga ir jo aplinkoje kelis kartus didesnė nei kelyje su asfalto danga ir iki 10 m atstumu nuo kelio viršijama leistinoji 0,5 mg m-³ koncentracijos vertė. Didžiausias dulkių sklaidos sulaikymas nustatytas pakelėje su liepų augmenija. Ištyrus dulkių dalelių kiekį pagal jų dydį (15 m atstumu nuo kelio krašto kur gyventojai dažniausiai būna lauke) nustatyta, kad pravažiavus pavienei transporto priemonei daugiausiai užfiksuota smulkiųjų (0,3-0,49 μm) dalelių - apie 45000 vnt. m-³. Ištyrus pavienės transporto priemonės sukeltą triukšmą nustatyta, kad asfalto ir žvyro dangų keliuose atviroje vietovėje 15 m atstumu nuo kelio garso lygis 6 dBA didesnis žvyruoto kelio atveju. Žvyro kelyje kai nėra kelkraštėje jokios natūralios atitvaros garso lygis 15 dBA didesnis nei kelyje su užtvara. Esant skirtingoms kelio kelkraštėje augmenijos užtvaroms, už jų triukšmo slopinimas skyrėsi apie 10 dBA, o efektyviausiai triukšmą slopina įvairių želdinių augmenija. / The main idea of this work - a comprehensive investigate dust and noise, gravel roads of rural settlements in the environment and natural greenery influence to the level of pollution. After finishing this research showed that concentrations of dust on the road with partition with a gravel surface and its atmosphere are several times higher than on the road with partition with asphalt and up to 10 m from the road exceeded the permissible 0.5 mg m-³ concentration value. The maximum delay dispersion of dust at the roadside with the lime trees. After research the amount of dust particles by size (15 m from the edge of the road where people is usually outdoor) found that the passing of single vehicle mostly recorded small (0.3 to 0.49 µm) particles - about 45,000 units. m-³. After research individual vehicle noise found that the asphalt and gravel roads in an open area of 15 m from the road sound level 6 dB above the gravel road. On gravel on the road with partition where there is no natural roadside partitions sound level 15 dB higher than the on the road with partition. At roadside vegetation in different road barricades for the noise attenuation of 10 dB difference, and the most effective noise levels of various plantation vegetation.
137

Investigation Of The Relationship Between Aerosol And Rainwater Composition

Turkum, Ahmet 01 September 2004 (has links) (PDF)
Chemical composition of particles and rain water at three sites in Turkey were extensively compared to determine if there is a relationship between aerosol and rain composition. If such relationship exists, it can allow one to construct rain water composition using aerosol data. This is important because, rain composition data is scarce as sampling and analysis of very low concentrations of elements and ions in rain water is more difficult compared to sampling and analysis of atmospheric aerosol. Results showed that aerosol composition can be closely reflected in composition of rain water if below cloud processes dominate over the incloud processes. This is clearly observed for crustal elements in all stations and for most of the elements in urban Ankara station. However, in rural stations there were differences in rain and aerosol that is attributed to significant contribution from in cloud processes. Seasonal patterns and enrichment factors observed in aerosol composition showed general agreement with corresponding temporal variations observed in rain water concentrations of elements, but short term variations became visible only if data is averaged over a long period of time. These observations suggest that certain features of rain water composition can be constructed from if concentration data is available for aerosols. However it should be noted that there are also significant differences between stations and between elements or element groups, indicating that composition of rain water constructed from aerosol data can only be a crude one. Similarities between rain and aerosol compositions is more pronounced in urban Ankara station compared to rural stations used in this study. Factor analysis performed to aerosol and rain water data sets showed that source types affecting chemical composition of rain and particles are generally the same, bur contribution of each source type to rain and aerosol composition shows differences. Similarly, the source regions, defined by potential source contribution function, affecting aerosol and rain compositions are not identical. In Antalya station Source regions affecting chemical composition of rain water are more local compared to source regions affecting composition of aerosol. Same difference is not observed in Amasra station. Scavenging ratios is found to be a suitable tool to construct rain water composition using aerosol data. Scavenging ratios calculated using paired daily data are more variable both between stations and within a station. Long-term averaged data was found to be more reliable for calculating SRs of elements and ions at all stations.
138

Reducing toxics is coercion or encouragement the better policy approach?

Hearn, Susan. January 2002 (has links)
Dissertation (D.P.H.)--University of Michigan.
139

Reducing toxics is coercion or encouragement the better policy approach?

Hearn, Susan. January 2002 (has links)
Dissertation (D.P.H.)--University of Michigan.
140

Análise multielementar em folhas de Nerium oleander L. usando fluorescência de raios X por dispersão em energia / Multielement analysis in leaves of Nerium oleander L. using energy dispersive X-ray fluorescence

Ramon Silva dos Santos 04 August 2014 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Desde o início do século XX, a poluição do ar nos grandes centros piorou em consequência processo de industrialização e urbanização, juntamente com o rápido crescimento populacional e do transporte motorizado. Algumas espécies de plantas absorvem os poluentes atmosféricos pelas suas folhas e então, fixa-os em sua matriz, tornando-se assim um biomonitor de poluição nessa área. Assim, a análise foliar dessas espécies de vegetal pode ser usado como monitoramento ambiental. Uma das plantas que tem a habilidade de reter certos elementos químicos do ambiente e pode ser usada como biomonitor é a Nerium oleander L.. Neste estudo utilizou-se folhas de Nerium oleander L. para avaliar os níveis de poluição ambiental em uma sub-região da Região Metropolitana do Rio de Janeiro através da Fluorescência de Raios X (EDXRF). O sistema de EDXRF foi desenvolvido no próprio laboratório e consiste de um sistema portátil de XRF formado por um mini tubo raio X de baixa potência (anodo de Ag e operação em 20 kV/50 μA) e um detector de SiPIN. As amostras de Nerium oleander L. foram coletadas de plantas adultas. As amostras foram coletadas durante as quatros estações do ano (verão, outono, inverno e primavera). Todas as folhas foram coletadas a uma distância superior de 1,5 m em relação ao solo. As amostras foram acondicionadas em sacos plásticos e depois da chegada ao laboratório foram colocados sob refrigeração a 5 C. No laboratório, as amostras foram limpas com um pincel com cerdas macias para retirar a poeira. Depois disso, as amostras foram colocadas na estufa a 60 C por 48 h. Em seguida, as amostras foram pulverizadas (44 μm). Depois desse processo, alíquotas de 500 mg de massa foram prensadas a uma pressão de 2.32×108 por cerca de 15 minutos, afim de se obter pastilhas finas com diâmetro de 2,54 cm e densidade superficial de 100 mg/cm2. Foi possível detectar a concentração de 13 elementos: S, Cl, K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr, Ba e Pb. A partir da concentração de cada elemento foram obtidos os mapas de distribuição elementar da área de estudo para cada estação. A análise da correlação de Pearson mostrou que existe uma correlação significativa entre os elementos Fe, Zn, Ba e Pb, entre os elementos Ca e Sr e entre os elementos Cl, K, Rb. A análise do PCA (Análise por Componentes Principais) mostrou que existem dois fatores principais da emissão de poluição ambiental: emissão por ressuspensão do solo (Cl, K, Ca, Mn, Rb e Sr) e emissões veiculares e industriais (Fe, Zn, Ba e Pb). O estudo da poluição ambiental através da técnica de EDXRF utilizando folhas de Nerium oleander L. como biomonitor se mostrou uma técnica de baixo custo e eficiência substancial na determinação da concentração elementar dos poluentes atmosféricos. / Since the early 20th century, the air pollution in the great urban areas has worsened as a result of the industrialization and urbanization processes, jointly with the rapid population growth and the motorized transport. Some plants species absorb the air pollutant atmosphere by the leaves and then fixed them in its matrix, thus becoming a biomonitor of pollution in that area. Thus, the foliar analysis of these vegetal species can be used to environmental monitoring. One of the plants that have the ability to retain certain chemical elements in the environmental and it can be used as a biomonitor is the Nerium oleander L.. In this study were used Nerium oleander L. leaves to measure the environmental pollution levels in a sub-region in the Rio de Janeiro Metropolitan Region-Brazil through the X-ray Fluorescence (EDXRF). The EDXRF system was developed in the own laboratory and consist of a portable XRF system formed by a mini X-ray tube of low power (anode of Ag and operated in 20 kV/50 μA) and a SiPIN detector. The samples of Nerium oleander L. were collected from adult plants. The samples were collected during the year seasons (summer, fall, winter and spring). All the leaves were collected at a distance superior of a 1.5 m relative to the soil. The samples were packed in plastic bags and after the arrival in the Laboratory were placed under refrigeration at 5 C. In the laboratory, the samples were cleaned with a brush with soft bristles to remove dust. After that, the samples were placed in the stove at 60 C for 48 h. Next, the leaves were powdered (325 mesh). After this process, aliquots of 500 mg mass were pressed at a pressure of 2.32×108 Pa for about 15 minutes, order to obtain thin pellets with a diameter of 2.54 cm and superficial density of 100 mg/cm2. It was possible to determinate 13 elements concentration: S, Cl, K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr, Ba and Pb. From the concentrations of each element were obtained the elemental distribution maps of the studied area in each season. The Pearson's correlation analysis shows a significant correlation between the elements Fe, Zn, Ba and Pb, between the elements Ca and Sr and between the elements Cl, K and Rb. The PCA (Principal Components Analysis) analysis shows that there is two mainly factors of the environmental pollution emissions: emission through the resuspension of the soil (Cl, K, Ca, Mn, Rb and Sr), vehicular and industrial emission (Fe, Zn, Ba and Pb). The study of the environmental pollution using the Nerium oleander L. leaves as a biomonitor proved an inexpensive technique and substantial efficiency in the determination of elements concentration.

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