• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 79
  • 10
  • 8
  • 8
  • 8
  • 8
  • 8
  • 8
  • 6
  • 3
  • 3
  • 2
  • Tagged with
  • 132
  • 132
  • 132
  • 44
  • 40
  • 40
  • 25
  • 23
  • 21
  • 19
  • 17
  • 15
  • 13
  • 12
  • 12
  • 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.
111

Como os conceitos da gestão da qualidade total podem ser aplicados na prevenção da poluição / How the concepts of total quality management can be applied in the pollution prevention

Teixeira, Jose Jeronimo 26 July 2006 (has links)
Orientador: Waldir Antonio Bizzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T12:39:32Z (GMT). No. of bitstreams: 1 Teixeira_JoseJeronimo_M.pdf: 3154194 bytes, checksum: 13a52d93232407233021e17738343814 (MD5) Previous issue date: 2006 / Resumo: O desempenho ambiental de uma organização vem tendo importância cada vez maior para as partes interessadas (consumidor, acionista, colaboradores e sociedade). Atingir um desempenho ambiental adequado requer o comprometimento da organização, uma abordagem sistemática e uma busca contínua da melhoria da qualidade do meio ambiente. O propósito desta dissertação é demonstrar como os conceitos de prevenção da poluição, podem ser implementados em uma organização utilizando-se um ou todos os conceitos de gestão da qualidade total, baseado nos quatorze (14) princípios de Deming. A partir deste ponto foi realizada uma reformulação dos quatorze (14) princípios de Deming com foco na prevenção da poluição e aplicados a duas organizações da área química. Os resultados obtidos são apresentados, ao final, demonstrando que o uso de uma visão sistêmica na prevenção da poluição, com base nos conceitos da qualidade total, é possível atingir resultados significativos na melhoria da qualidade do meio ambiente / Abstract: The environmental performance of an organization comes tends an importance every time larger for the interested parts (customer, stakeholder, employees and society). An appropriate environmental performance requests the compromise of the organization, a systematic approach and a continuous improvement of the quality of the environment. The purpose of this dissertation is to demonstrate how concepts of pollution prevention can be implemented in an organization being used one or all of the concepts of the total quality management, based on the fourteen (14) points of Deming. In this dissertation, the concepts of the total quality management and pollution prevention are presented and discussed. Next step, the fourteen (14) points of Deming have been reworded with focus in the pollution prevention and applied to two organizations of the chemical area. The obtained results are presented, at the end this dissertation, demonstrating that the use of a systemic approach in the pollution prevention, with base in the concepts of the total quality, is possible to reach significant results in the improvement of the quality of the environment / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
112

L'impact de l'activité humaine sur la composition chimique de la troposphère au-dessus de l'Océan Pacifique: développement d'un modèle téléscopique de chimie et de transport atmosphériques et interprétation des résultats de la campagne de mesure MLOPEX

Ginoux, Paul 19 September 1997 (has links)
<p align='justify'>De manière à mieux comprendre l'impact des émissions anthropiques sur la troposphère reculée, les concentrations d'un nombre important de composés atmosphériques ont été mesurés dans la troposphère libre au-dessus d'Hawaii durant la campagne Mauna Loa Observatory Photochemistry Experiment (MLOPEX) accomplie au cours des années 1991 et 1992. Le constituant chimique fondamental pour évaluer cet impact est le radical hydroxyle OH qui fut mesuré au printemps et en été de l'année 1992. La variation diurne de la direction du vent génère pendant la journée un mélange des masses d'air de la couche limite planétaire avec la troposphère libre. Actuellement les modèles régional et global de chimie troposphérique ne peuvent tenir compte à la fois du transport à grande échelle et du mélange local. Nous avons développé un modèle tridimensionnel qui nous permet d'analyser la chimie et la dynamique troposphérique à ces deux échelles. Pour ce faire, nous avons utilisé une grille non-structurée qui offre un moyen efficace de caractériser la région d'Hawaii à l'aide d'une haute résolution et le restant de l'hémisphère Nord avec une résolution qui décroît au fur et à mesure que l'on s'éloigne d'Hawaii. La distribution de 46 composés gazeux avec 138 réactions, incluant une chimie détaillée des hydrocarbures non-méthaniques (isoprène, éthane, éthène, propène et alpha-pinène) est calculée avec un pas de temps de 20 minutes. A l'aide de notre modèle nous avons simulé une période de huit jours pour chacune des saisons. Les résultats des simulations ont été comparés aux observations et interprétés à l'aide d'études de rétro-trajectoires, de traceurs passifs et de bilans chimiques local et régional de l'ozone et de ses précurseurs.</p><p><p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
113

The impact of environmental pollution on public health with specific reference to Sasolburg industrial area, South Africa

Moshanyana, Lineo Grace January 2013 (has links)
The Mining industry in South Africa is viewed as the backbone of the country’s economy, while benefiting from this engine of economic development, its impact on the environment and health has been of a major concern to different stakeholders. The majority of people acknowledge the role of mining in the economy and the country. Others put more emphasis on public health and the environment. The aim of the study was then to assess the impact of environmental pollution and public health on the Sasolburg community from a developmental perspective. The present study can be described as a quantitative descriptive survey that uncovered serious levels of pollution in Sasolburg that had dire health consequences for people involved. The findings of the study indicate that residents live with the constant smell of a variety of chemical pollutants released both by normal production and by periodic incidents. They experience chronic respiratory symptoms, burning eyes, hearing deficiency and skin irritations. The study revealed that environmental pollution consequences affecting residents are inversely related to distance from the mines. The results obtained in this study are evidence that environmental pollution in the Sasolburg area is a definite risk to the health of people living within the surrounding area. Although indicating the need to carry out a comprehensive study, the results call for immediate action to prevent continued public over-exposure to environmental pollution.
114

Prevalence and antibiogram of some swine associated Shiga toxin producing Escherichia coli Serogroups and Salmonella species in Nkonkobe Municipality, Eastern Cape Province, South Africa

Iwu, Chinwe Juliana January 2015 (has links)
Gastrointestinal illnesses have continually become a global public health issue. Exposure to zoonotic food borne pathogens such as Salmonella and diarrhoegenic E. coli either by direct or indirect contact through the consumption of food producing animals is likely an important mode of infection to humans. More so, the use of antibiotics in farm animals similar to those used in humans can select for resistance in bacteria frequently harboured by them. These resistant strains can be passed on to humans through contaminated meat products and water leading to resistant infections with consequences such as prolonged illnesses, treatment failures, and increased morbidity and mortality. In animals, these can lead to reduced productivity. Monitoring the level of resistance among bacteria from animal isolates will help in generating data that could be used to create awareness of their presence in the environment and aid in preventing a potential epidemic in the community. In this study, we investigated the prevalence and antimicrobial resistance profile of Escherichia coli serogroups and Salmonella species in faecal samples collected from pigs in Nkonkobe Municipality in the Eastern Cape Province, South Africa between April – July, 2014. A total of 310 presumptive Shiga toxin producing Escherichia coli (STEC) were confirmed as E. coli spp using polymerase chain reaction (PCR) technique by amplification of the uidA gene, out of which 179 (58%) were confirmed positive. Approximately, serogrougs O157:H7, O145 and O26 made up 24% (n=43), 8% (n=14) and 20% (n=35) of the E. coli population respectively. Only E. coli O26 was positive for stx2 gene in 31% of the isolates harbouring the gene, while the other serogroups were non-pathogenic. Susceptibility of the isolates to 18 antibiotics was carried out in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem. Similarly, a relatively high susceptibility was observed in norfloxacin (83-100%), ciprofloxacin (63-100%), gentamycin (77-100%), and chloramphenicol (77-100%). However, all the isolates were resistant to tetracycline and its long acting counterpart oxytetracycline. Resistances observed against other antimicrobials are as follows: ampicillin (84-91%), streptomycin (14-100%), erythromycin (91-100%), ceftazidime (35%). Multiple antimicrobial resistance patterns and indices ranged from 3 to 12 and 0.2 to 0.7 to respectively. Genes encoding resistances to ampicillin (ampC), streptomycin (strA) and tetracycline (tetA) were frequently detected in 50-100%, 22-29% and 40-86% of the resistant isolates respectively. In the other arm of the dissertation, two hundred and fifty eight presumptive isolates of Salmonella were recovered from the faecal samples of pigs. Specific primers targeting serogroups A, B, C1, C2, and D were used to delineate the isolates into different serogroups using PCR. Only serogroup A (n=48) was detected. These isolates were examined for antimicrobial susceptibility by disc diffusion method using 18 antibiotics. The results showed that a large proportion of the isolates were resistant to tetracycline (100%), oxytetracycline (100%), ampicillin (75%), sulphamethoxazole/trimethoprim (75%) and streptomycin (75%). Majority of the isolates exhibited multidrug resistances with the predominant multiple antibiotic resistance (MAR) phenotype being against eleven antibiotics. A high multiple antibiotic resistance (MAR) index in a range of 0.3- 0.6 was observed. The incidence of genes encoding resistance against tetracycline (tetA), streptomycin (stra), and ampicillin (ampC) were 54%, 44% and 61% respectively. These findings reveal that pigs within the Nkonkobe Municipality in the Eastern Cape Province could harbour Shiga toxins and multidrug resistant serogroups of E. coli as well as resistant Salmonella which could be transmitted to humans through the food chain. To ensure public health safety, continuous monitoring and sufficient sanitation in swine industries must be ensured.
115

Sistemas inteligentes aplicados à análise de riscos ambientes

Albuquerque Filho, Francisco Sales de 17 October 2012 (has links)
Made available in DSpace on 2017-06-01T18:20:37Z (GMT). No. of bitstreams: 1 dissertacao_francisco_sales.pdf: 1424498 bytes, checksum: 31e4dca2f34d83cb1a300966669297f2 (MD5) Previous issue date: 2012-10-17 / In order to forecast and classify environmental risks, artificial intelligence (AI) techniques were applied to the air quality problem. Predetermined gaseous pollutant concentration data were acquired with the intent of predicting the risks. Such concentrations are denominated air quality indicators, and are regulated all around the world, including by brazilian law. The data concerning these indicators were used in a model that consists of two AI techniques: artificial neural networks and particle swarm optimization. The air quality indicators concentration prediction resulted in one day ahead values. The risk modeling utilizes the predictions as inputs values, correlating them in order to obtain the resulting air quality and, the risk that such quality has upon the human health. The risk model is based on a third AI technique, called fuzzy logic. The present work obtained two main results. The first was the accurate forecasts made by the prediction model. The second was the achievement of a coherent classification of the risks. / Este trabalho aplica técnicas da área de inteligência artificial (IA) com o intuito de prever e classificar riscos ambientais, com o foco no problema da qualidade do ar. Para prever os riscos, dados foram adquiridos acerca das concentrações gasosas de determinados poluentes. Tais concentrações, denominadas de indicadores da qualidade do ar, são regulamentadas por várias legislações ao redor do mundo, inclusive a do Brasil. Estes dados foram empregados em um modelo que consiste de duas técnicas de IA: redes neurais artificiais e otimização por enxame de partículas. O resultado do modelo é a previsão de um dia adiante das concentrações gasosas dos indicadores da qualidade do ar. As previsões são usadas como entradas para a modelagem de riscos. A modelagem de riscos correlaciona as previsões dos poluentes observados para obter a qualidade do ar e o risco que tal qualidade oferece à saúde humana. O modelo de risco é baseado em lógica nebulosa, uma terceira técnica de IA. Ao término do trabalho, dois resultados foram alcançados. O primeiro foi o modelo de previsões que obteve resultados com um bom nível de acuidade. Em seguida, o modelo de riscos foi capaz de alcançar uma classificação coerente dos riscos ambientais.
116

A life cycle assessment on liquid biofuel use in the transport sector of Ethiopia

Dereje Kebede Abebe 06 1900 (has links)
Seed-oil based biodiesel production particularly biodiesel production from the nonedible oil seed bearing plant - Jatropha curcas L. - is a key strategic direction outlined in the biofuels strategy of the Government of Ethiopia. The main objective underlying the strategy include substitution of imported diesel oil used in the road transport sector while at the same time contributing to the local and global greenhouse gasses (GHG) reduction efforts. In this study the environmental benefits and costs of production and use of Jatropha biodiesel in the road transport sector of Ethiopia is assessed using a life cycle analysis (LCA) methodology. The analysis focused on determining the potential environmental impacts and net non-renewable energy saving potential of biodiesel from Jatropha oil-seeds using the following metrics: (i) Net Greenhouse Gas (GHG) reduction, and (ii) Net Energy Balance (NEB) relative to diesel oil. The study shows that the net GHG emissions reduction potential of Jatropha Methyl Ester (JME) is highly influenced by the magnitude of initial carbon loss occurring in the process of conversion of different land uses to Jatropha plantation, and less so on other unit processes of JME production system analysed. The NEB of JME relative to use of diesel oil per functional unit of one GJ is less sensitive to impacts of land use change and is generally positive. Where no land use change impacts is considered, or where Jatropha is grown on lands with low carbon stock such as grasslands, substitution of diesel oil with JME in Ethiopia can provide GHG emission reduction of about 43%, and for each MJ of JME produced the nonrenewable energy requirement will be 0,38 MJ. Production of JME by converting lands with high above ground, below ground and/or soil carbon stocks such as shrub lands or well stocked forest lands will result in net loss of carbon and require ecological carbon payback time of 50 to hundreds of years. The impact of introducing and use of JME-diesel oil blends by Anbassa City Bus Services Enterprise (ACBSE) bus fleets shows that, displacement of diesel oil with JME that have positive GHG reduction potential, will also contribute to the reduction of air pollutants and improvement of ambient air quality in Addis Ababa. Two key recommendations of this research work are that to ensure environmental sustainability of biodiesel production from Jatropha seeds (i) land availability and land suitability assessment for estimating the potential available land for Jatropha (and other oil-seed bearing plants) shall be conducted, and (ii) minimum requirements on GHG reduction and NEB requirements on biodiesel shall be established. / Environmental Sciences / M. Sc. (Environmental Management)
117

Biogenic silica and diatom centricpennate ratios as indicators of historical coastal pollution

Spasojević, Zorana January 2002 (has links)
No description available.
118

Assessing the influence of internal environmental management systems on green packaging management, green information systems and organisational performance

Mahlangu, D. M. 26 July 2021 (has links)
Ph. D. (Department of Logistics Management, Faculty of Management Sciences), Vaal University of Technology. / The effective practice of green supply chain has been a focus of both practitioners and researchers for almost a decade, mostly focusing on greenhouse effects and implementing full green supply chain control systems. However, not much attention has been given to empirical relationships between internal environmental management systems, green packaging management, green information systems adoption and organisational performance. The chief objective of this study was to assess the internal environmental management factors of the plastic packaging manufacturing organisations in Gauteng province in South Africa, mainly focusing on the three major internal environmental factors, namely pollution prevention plans, total quality management and environmental audits. Secondly, the study aimed to determine the relationship between green packaging management, green information systems and organisational performance. A positivist approach was used as this study is quantitative. A total number of 250 questionnaires were distributed to managers and employees of the chosen plastic packaging organisations. Although 250 questionnaires were distributed to the chosen organisations, only 230 were deemed to be fit for capturing due to some errors on the other 20 questionnaires. For data analysis the Statistical Package for Social Sciences (SPSS 24) was used to generate frequency tables and graphs. Furthermore, structural equation modelling (SEM) was used to generate regression weights and standard regression weights. The factor loading was also generated using SEM as well as model fitness and path co-efficiency values. A detailed research approach was followed using a sample size of 230; the results of this study show that there is a positive significant relationship between internal environmental management systems, green packaging management and green information systems. Further, it was found that most organisations that adopt green management systems are more likely to perform better than those that do not. The study also discovered that the government policies that place emphasis on green practices, not only pressurise organisations, but also help them to be strategic. Most plastic packaging manufacturing organisations usually find it difficult to operate without polluting the environment, but this study discovered that if they control their internal environmental systems, it will be easy for these organisations to adopt environmental management systems and produce green products. Also, given the changing market environments, currently most consumers prefer green products and if organisations go green this might open up new markets for their new products and enhance performance. This study examined the importance of green packaging management from the perspective of both government policies and organisational policies. The results showed that some organisations are still struggling to align their internal environmental management process with the external environment; however, the market changes are enforcing that most plastic packaging organisations start aligning their internal management systems with external systems, as it gives them opportunities towards new products and new competitive strategies that will lead to better performance. An environmental management framework was developed in this study. The framework aims to help guide plastic manufacturers with their long- and short-term strategies. In line with non-linear relationships between variables, the study recommends the following to the plastic packaging organisations: to create pollution prevention policies and strategies to improve organisational performance by eliminating pollution and avoiding penalties from the government. Pollution prevention plans, total quality management and environmental audits were used as independent variables to measure organisational performance. In line with the linear relationship between the adoption of green packaging management and organisational performance, it is recommended to the plastic packaging organisations that enterprises facing slow-moving sales growth, profitability and general performance challenges, should use green technologies as a remedy for their problems.
119

Land pollution and population density : the case of Kwekwe City residential areas, Zimbabwe

Chatsiwa, Jaison 02 1900 (has links)
In most developing countries, the problem of inefficient municipal solid waste management (MSWM) is endemic. The problem is manifested by heaps of uncollected solid waste found on open areas and by the street sides. This dissertation examines the relationship between land pollution and population density resulting from solid waste generation in the City of Kwekwe in Zimbabwe. Questionnaires and interviews were conducted to 375 randomly selected households in low, medium and high density residential suburbs. The household survey was triangulated with field observations, key informant interviews and secondary data sources. The average household size in high, medium and low density residential areas was 11, 8 and 5 people respectively. The study revealed that the amount and composition of solid waste generated varied according to household size, income and education levels of residents. The higher the population density, the more the solid waste produced. However, waste generated was not carried to the dumpsites for disposal. Also the higher the income, the higher the amount of solid waste produced, although residents with high income were able to ferry their wastes to the dumpsites hence less land pollution. The solid waste generation rate in high density areas was 0.04 kg/capita day, in medium density areas was 0.35 kg/capita/day and in low density areas were 0.84 kg/capita/day. It was also observed that among high income earners, the educated people produced more waste than low income earners. However, the low income earners and the less educated people could not take care of their environment to limit roadside and open space littering. However, lack of public awareness coupled with inefficient and ad hoc waste management system continue make provision of effective solid waste management services illusive. Based on the research findings, it is suggested sound environmental stewardship amongst residents will limit land pollution in the city of Kwekwe. / Environmental Sciences / M.A. (Environmental Management)
120

Contamination levels in and cellular responses of intertidal invertebrates as biomarkers of toxic stress caused by heavy metal contamination in False Bay

Mdzeke, Naomi Patience 03 1900 (has links)
Thesis (PhD) -- Stellenbosch University, 2004. / ENGLISH ABSTRACT:Heavy metals are persistent environmental contaminants whose sources of inputs into the environment are both natural and anthropogenic. The levels of heavy metals (cadmium, copper, nickel, lead and zinc) in the False Bay intertidal zone were measured in the water, sediments and invertebrate species between August 2000 and August 2001. The results of the water and sediment analyses revealed that most pollution was associated with the northern shore of the bay between Strand and Muizenberg, where the most populated and industrial catchments occur. Significant spatial variations occurred, indicating the presence of localised contamination, while seasonal variations may be related to changes in precipitation and runoff at different times of the year. The concentrations of cadmium, nickel and lead were occasionally higher than the levels recommended by the South African Water Quality Standards. The possible sources of pollution at the different sites are also discussed. The concentrations of the five metals in the different invertebrate species (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) also revealed significant seasonal and spatial variations, with both the soft tissues and shells accumulating heavy metals. The barnacle T serrata from Rooiels had the highest cadmium concentration (70.67 J.lg/g dry weight), which may be related to historic pollution inputs from the military activities which took place at a weapons testing site at this site between 1987 and 1994, although no evidence was found to confirm this. The periwinkle 0. tigrina from Strand had the highest copper concentration (70.25 J.lg/g) while the limpet P. oculus from the same site had the highest nickel concentration (35.75 J.lg/g). The shells of the mussel C. meridionalis from Muizenberg had the highest concentration of lead (25.75 J.lg/g). Since cadmium occurs as a constituent of phosphate fertilisers used widely in the False Bay catchments, the effects of cadmium exposure on the different species were investigated during 14-day laboratory exposures to 200 and 400 J.lg/LCdCh. The results revealed a general pattern of tissue metal increase in the exposed organisms, followed by slight reductions after decontamination in clean seawater. The viscera and kidneys of C. meridionalis accumulated most of the dissolved cadmium. The shells of the mussels also accumulated cadmium, indicating the possible use of shells as a detoxification matrix. / AFRIKAANSE OPSOMMING:Swaarmetale is persisterende omgewingskontaminante waarvan die insetbronne beide natuurlik of van menslike oorsprong kan wees. Die kontaminasievlakke van swaarmetale (kadmium, koper, nikkel, lood en sink) in die Valsbaai tussengetysone is in die water, sedimente en invertebraatspesies bepaal vanaf Augustus 2000 tot Augustus 2001. Voorlopige resultate van die water- en sedimentontledings het getoon dat die meeste besoedeling by die noordelikke oewer van die baai voorgekom het tussen Strand and Muizenberg, waar die mees digbewoonde en ge-industrialiseerde opvangsgebiede is. Betekenisvolle ruimtelike en seisoenale variasie het in die konsentrasies van swaarmetale voorgekom, met die ruimtelike variasie wat moontlik gelokaliseerde kontaminasie aandui terwyl die seisoenale variasies weer verband mag hou met veranderings in die neerslag en afloop gedurende verskillende tye van die jaar. Die konsentrasie van kadmium, nikkel en lood was somtyds hoer as die vlakke wat deur die Suid-Afrikaanse Waterkwaliteitsstandaarde voorgestel word. Die moontlike bronne van besoedeling in die verskillende areas is ook in bespreking genoem. Die konsentrasies van die vyf swaametale in die verskillende invertebraatspesies (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) het ook seisoenale en ruimtelike variasies vertoon, die swaarmetale het in die sagte weefsel en skulpe van die invertebrate geakkumuleer. Die hoogste gemiddelde konsentrasie van kadmium (70.67 ).lg/g droe massa) is in die heel-liggaam monsters van die eendemossel T serrata gemeet wat by Rooiels versamel is. Die vlakke mag verband hou met die oprigting en aktiwiteite van die wapentoetsingsaanleg in die opvanggebied van die Rooiels lokaliteit tussen 1987 en 1994, maar geen bewyse daarvan is gevind nie. Die tolletjie, 0. tigrina wat in die 10kaliteit by Strand versamel is het die hoogste gemiddelde konsentrasie koper gehad 70.25 pig droe massa), terwyl die klipmossel P. oculus by dieselfde versamelpunt die hoogste konsentrasie nikkel (35.75 ).lg/gdroe massa) gehad het. Eksperimentele studies is ook uitgevoer op vier invertebraat spesies wat vir 14 dae in akwaria blootgestel is aan see-water met 200 en 400 p,g/L CdCh, en daama gedekontamineer is in skoon seewater. / The NRF and the University of Stellenbosch, for funding this study.

Page generated in 0.2762 seconds