Uma pesquisa de campo foi conduzida para verificar as condições reais de utilização de clorofluorcarbonos em sistemas de refrigeração e de condicionamento de ar. A pesquisa cobriu os setores de refrigeração de supermercados, ar condicionado de edifícios e oficinas de reparação e de manutenção de geladeiras, \"Freezers\" e condicionadores de ar compactos e automotivos. A região escolhida para a pesquisa está localizada no município de São Paulo, tendo uma superfície de 12,504 Km2. As seguintes conclusões principais resultaram deste estudo: Predomina o consumo do HCFC 22 nos usuários pesquisados; a reciclagem e a recuperação ocorrem em pequena escala na região estudada; os sistemas de condicionamento de ar automotivos são a fonte mais significativa de substâncias agressivas à camada de ozônio, nos usuários pesquisados; vazamentos ocorrem por práticas de serviço não adequadas; a utilização do CFC 11 para limpeza de circuitos reduz o ganho obtido em sistemas que empregam o HCFC 22; a manutenção preventiva mostrou ser eficaz tanto para reduzir o consumo de gás refrigerante, como para reduzir a substituição de peças e componentes; a reciclagem e a recuperação do gás refrigerante tem efeito positivo em relação à camada de ozônio, economiza recursos naturais, reduz o consumo de energia, os riscos ao meio ambiente e à saúde da comunidade em geral. Finalmente, são feitas recomendações para o estabelecimento de um programa efetivo de reciclagem e recuperação de gases refrigerantes. / A field study was performed for verifying the actual conditions of the use of chlorofluorcarbons in refrigeration and air conditioning systems. The study has covered the sectors of supermarket refrigeration, building air conditioning systems, and refrigerators freezers and compact and automobile air conditioning systems repair shops. The region chosen for this study is located in the city of Sao Paulo and it has an area of 12.504 km2. The following conclusions resulted from the study: There is a predominance of the of HCFC 22 in the systems surveyied; recycling and recuperation are used in small scale in the region of the study; in the users covered by the study, the automobile air conditioning sector is the most important source of emission of ozone depleting substances; leaks occur because of bad service practices; the use of CFC 11 for circuit cleaning decreases the the gain obtained with the use of HCFC 22; the preventive maintenance has proved to be very efficient both for reducing the consum of refrigeration gases and for reducing the consum of parts and components of the refrigeration system; recycling and recuperation of refrigeration gases have positive effects in relation to the ozone layer, it saves natural resources, and reduces the risk to the enviromnent and to the public health. Finally, recommendations are made for the establishment of an effective refrigerant conservation program.

Surface deposition is an important sink for tropospheric ozone. The rate of ozone deposition may be measured by measuring the downward flux of ozone in the atmospheric surface-layer. This thesis presents eddy correlation measurements of ozone fluxes, taken on eight days in August, 1994, at a grassland site located in the Lower Fraser Valley of British Columbia. Surface resistances to ozone deposition were calculated from the flux measurements. Much of the variability in measured surface resistances was found to be attributable to variations in ambient light levels and in the degree of moisture stress at the site. Measurements of surface resistance from this site agreed quite well with other measurements of ozone deposition to grassland surfaces. Measured surface resistances were compared to surface resistances calculated using the Wesely (1989) parameterization (W89) for surface resistance. W89 underestimated surface resistance, particularly in the mid afternoon and early evening. This was attributed to the model's neglect of the effects of water stress on stomatal resistance, as well as to a low value for resistance to ground surface deposition in the model. The eddy correlation fluxes were compared to ozone fluxes derived using an assumption of cospectral similarity between ozone and heat flux and to ozone fluxes measured using the variance method and the gradient method. The cospectral similarity method worked well and allowed a considerable relaxation of the sampling speed requirements of the eddy correlation method. The variance method produced biased flux measurements due to high frequency noise from the ozone sensor. Flux measurements using the gradient method had a great deal of scatter, due to inaccuracies in the measurement of gradients.

The aim of this thesis is to examine the nature and characteristics of tropospheric ozone over Johannesburg, South Africa. Ozone, water vapour and meteorological profile data, which form part of the MOZAIC (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft) database for the period 1995 to 2000 were utilized in this study. The thesis is divided into two main parts. The first part deals with the computation of total tropospheric ozone. A clear seasonal cycle, with ozone peaking in September and October is found. It is suggested that the main reason for the spring maximum is biomass burning, combined with prevailing anticyclonic circulation patterns, which facilitate the build-up of ozone over the region. Variability in TTO is greatest in January, September and November and least during autumn and winter (April to July). The lower day-to-day variability in autumn and winter is a reflection of the more settled weather at this time. Interannual variability is least in January and April to June. The autumn and winter ozone values are more consistent and appear to represent background tropospheric ozone loadings on which the dynamic and photochemical influences of other months are superimposed. High TTO events (>30 DU) occurred predominantly during September and October. Enhancements in the lower troposphere occurred mostly in September and seldom lasted for more than 1-2 consecutive days. It is suggested that these events are most likely due to effects of local surface pollution sources, either localised biomass burning or urban-industrial effects. An extended period of enhancement in the 7-12 km layer occurred from 14-17 September 1998 and again on 20 September 1998. The extended duration of this event suggests that it is due to an STE event. Confirmation of this was given in a case study of a particular MOZAIC flight on 16 September 1998 from Johannesburg to Cape Town. The second part of the thesis deals with the classification of ozone profiles and is used to find pattern and order within the profiles. TWINSPAN (Two-Way INdicator SPecies ANalysis), a cluster analysis technique, was used to classify the profiles according to the magnitude and altitude of ozone concentration. Six distinct groups of profiles have been identified and their characteristics described. The HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) trajectory model was used to relate the profiles to the origin of air masses, revealing clearly defined source regions. The mid-tropospheric peak in summer and the low to mid-tropospheric enhancement in spring is attributed to continental areas over central Africa and long-range transport while local sources are responsible for the winter low tropospheric enhancement. Reduced ozone values are due to westerlies bringing in clean maritime air. The classification has highlighted three important findings. Firstly, it has emphasized the pronounced seasonality of ozone profiles. It is evident that seasons are dominated by particular patterns and by inference, the processes and transport patterns that shape individual profiles are seasonally dependent. Secondly, the widely recognized spring maximum in tropospheric ozone has been confirmed in this classification, but a new and equally high summer mid-tropospheric enhancement due to the penetration of tropical air masses from continental regions in central Africa has been identified. Thirdly, it is suggested that the computation of a mean profile and furthermore, extrapolation of trends based on a mean profile is meaningless, particularly for a location on the boundaries of zonally defined meteorological regimes. / Thesis (M.A.)-University of Natal, Durban, 2002.

Surface deposition is an important sink for tropospheric ozone. The rate of ozone deposition may be measured by measuring the downward flux of ozone in the atmospheric surface-layer. This thesis presents eddy correlation measurements of ozone fluxes, taken on eight days in August, 1994, at a grassland site located in the Lower Fraser Valley of British Columbia. Surface resistances to ozone deposition were calculated from the flux measurements. Much of the variability in measured surface resistances was found to be attributable to variations in ambient light levels and in the degree of moisture stress at the site. Measurements of surface resistance from this site agreed quite well with other measurements of ozone deposition to grassland surfaces. Measured surface resistances were compared to surface resistances calculated using the Wesely (1989) parameterization (W89) for surface resistance. W89 underestimated surface resistance, particularly in the mid afternoon and early evening. This was attributed to the model's neglect of the effects of water stress on stomatal resistance, as well as to a low value for resistance to ground surface deposition in the model. The eddy correlation fluxes were compared to ozone fluxes derived using an assumption of cospectral similarity between ozone and heat flux and to ozone fluxes measured using the variance method and the gradient method. The cospectral similarity method worked well and allowed a considerable relaxation of the sampling speed requirements of the eddy correlation method. The variance method produced biased flux measurements due to high frequency noise from the ozone sensor. Flux measurements using the gradient method had a great deal of scatter, due to inaccuracies in the measurement of gradients. / Arts, Faculty of / Geography, Department of / Graduate

O presente trabalho tem o objetivo principal de compreender os possíveis efeitos da radiação energética de um evento de Gamma-Ray Burst (GRB) sobre o meio interestelar no entorno de seu local de geração e em planetas possivelmente iluminados. Gamma-Ray Bursts foram detectados pela primeira vez nos anos 60 e rapidamente atraíram a atenção da comunidade astrofísica, uma vez que as energias emitidas apenas em poderiam alcançar 1054erg, o equivalente a massa de repouso do Sol. Não se conhecia nenhum mecanismo tão eficiente para extrair energia gravitacional para produzir tal evento. Mais tarde, a possibilidade da emissão ser colimada abaixou a energia em para 5x1050erg, mas o mecanismo central de geração ainda não foi completamente desvendado, havendo muito espaço para alternativas exóticas. Estudamos os efeitos de um GRB sobre o meio interestelar, em uma tentativa de distinguir os remanescentes do GRB do gerado por múltiplas supernovas. Usamos argumentos energéticos e sobre a possibilidade de alterações químicas e isotópicas devido a reações fotonucleares. Também trabalhamos com as implicações biológicas da iluminação de planetas por um GRB, concluindo que os efeitos de tais eventos podem afetar seriamente a biosfera de um planeta mesmo a distâncias de ~10kpc. / The present work has the main goal of understanding the possible effects of the hard gamma radiation produced during a Gamma-Ray Burst (GRB) event both on the interstellar medium surrounding the source of the burst and on planets possibly illuminated. Gamma-Ray Bursts were first detected on the 60s and quickly have attracted the attention of the astrophysical community, since the energies emitted just in could reach 1054erg, the rest mass of the Sun. No mechanism was known to be so efficient in extracting gravitational energy to produce such emission. Later on, the possibility of the emission being collimated has lowered the energy of the to 5x1051erg, but the central engine has not yet been completely understood, and there is still ample room for exotic alternatives. We have studied the effects of GRB on the ISM, in an attempt to distinguish the candidates of GRB remnants from those generated by multiple supernovae. We have used both energetic arguments and the possibility of chemical alterations due to photonuclear reactions. We have also worked on the biological implications of the illumination of planets by a GRB, concluding that the effects of such event could seriously harm the biosphere of a planet even at distances of ~10kpc.

Thesis (M. Sc. (Statistics)) -- University of Limpopo, 2021 / The effects of ozone depletion on climate change has, in recent years, become a reality, impacting on changes in rainfall patterns and severity of extreme floods or extreme droughts. The majority of people across the entire African continent live in semi-arid and drought-prone areas. Extreme droughts are prevalent in Somalia and eastern Africa, while life-threatening floods are common in Mozambique and some parts of other SADC (Southern African Development Community) countries. Research has cautioned that climate change in South Africa might lead to increased temperatures and reduced amounts of rainfall, thereby altering their timing and putting more pressure on the country’s scarce water resources, with implications for agriculture, employment and food security. The average annual rainfall for South Africa is about 464mm, falling far below the average annual global rainfall of 860mm. The Limpopo Province, which is one of the nine provinces in South Africa, and of interest to this study, is predominantly agrarian, basically relying on availability of water, with rainfall being the major source for water supply. It is, therefore, pertinent that the rainfall pattern in the province be monitored effectively to ascertain the rainy period for farming activities and other uses. Modelling and forecasting rainfall have been studied for a long time worldwide. However, from time to time, researchers are always looking for new models that can predict rainfall more accurately in the midst of climate change and capture the underlying dynamics such as seasonality and the trend, attributed to rainfall. This study employed Exponetial Smoothing (ETS) State Space and Seasonal Autoregressive Integrated Moving Average (SARIMA) models and compared their forecasting ability using root mean square error (RMSE). Both models were used to capture the sporadic behaviour of rainfall. These two models have been widely applied to climatic data by many scholars and adjudged to perform creditably well. In an attempt to find a suitable prediction model for monthly rainfall patterns in Limpopo Province, data ranging from January 1900 to December 2015, for seven weather stations: Macuville Agriculture, Mara Agriculture, Marnits, Groendraal, Letaba, Pietersburg Hospital and Nebo, were analysed. The results showed that the two models were adequate in predicting rainfall patterns for the different stations in the Limpopo Province. / National Research Foundation (NRF)

107 Summary The Ozone layer of the Earth located in the stratosphere in an altitude of 20 to 50 kilometres is the important part of the gases surrounding the planet Earth. Its purpose is to absorb UV radiation that otherwise very negatively affects life on the Earth. During the twentieth century, this ability was weakened by the emission of substances proven much later to be very dangerous in this way. Until 1987, by various chemical reactions, in particular of chlorine atoms, the ozone hole has been formed over the South Pole of the Earth, not fully healed yet. In 1985, risk to human life led using the precautionary principle to the adoption of the Vienna Convention and subsequently of its implementing protocol including specific obligations especially the control measures of the production and consumption of ozone depleting substances and of the trade with them in 1987. The protocol was later modified by amendments and adjustments. This diploma thesis describes these acts with respect to their evolution and actual state of knowledge. At European level, it shows the evolution of the European environmental law in focus on the protection of the ozone layer and on the process of incorporation of international instruments in this area of environmental law. It describes these European acts and compares the...

Magistro baigiamojo darbo tema – Europos Bendrijos netarifinių prekybos reguliavimo priemonių aplinkos apsaugos srityje analizė ir perspektyvos. Darbe išsamiai aptariami esami ir numatomi reikalavimai cheminių medžiagų ir preparatų bei ozono sluoksnį ardančių medžiagų eksportui, importui ir tiekimui į rinką. Analizuojamos konvencijos, Europos sąjungos ir nacionaliniai teisės aktai, kad galima būtų atlikti EB netarifinių prekybos reguliavimo priemonių analizę ir numatyti perspektyvas. Darbe naudojama statistinių duomenų analizė, apimanti 2005 – 2007 metus, parodė, kad griežtėjant cheminių medžiagų ir preparatų eksporto, importo , tiekimo į rinką, o taip pat naudojimo reglamentavimui , jų vis mažiau importuojama į Lietuvos Respubliką. Taip pat sumažėjo ir kai kurių cheminių medžiagų ir preparatų eksportas. Ozono sluoksnį ardančių medžiagų vartojimo sumažinimą sąlygojo Lietuvoje įgyvendintos priemonės, visuomenės ir ūkio objektų informavimas apie jų daromą žalą, galimus šių medžiagų pakaitalus, apie Europos Sąjungos ir nacionalinius teisės aktų reikalavimus. Dauguma priemonių įgyvendinta pasinaudojus negrąžintina Pasaulio aplinkos fondo parama. Atlikus teisės aktų bei statistinių duomenų analizę, nustatyta, kad pasitvirtino darbe iškeltos hipotezės: prekėms, kurios daro žalingą poveikį aplinkai, prekybai taikomos griežtos netarifinės reguliavimo priemonės atitinka siekiamus švarios ir sveikos aplinkos tikslus; ieškoma ir randama alternatyvų pavojingų cheminių medžiagų ir... [toliau žr. visą tekstą] / The topic of Master‘s final work is the analysis and prospects of non tariff trade regulation means of the European Community in the sphere of environment protection. The present and foreseen requirements of export, import and supply to the market of chemical materials and manufactures and the materials which destroy the ozone layer are discussed in detail in the final work. Analizuojamos konvencijos, In order to perform the analysis and to foresee the prospects of non tariff trade regulation means of EC , the law acts of European Union and the national law acts , conventions are analyzed. The statistics data analysis of 2005-2007 , which was used in the work, showed that when the regulations of chemical materials export , import and supply to the market and also their usage , became stricter, less of such materials are imported to Lithuania. The export of some chemical materials and manifactures also decreased. The usage of the materials which destroy the ozone layer lowered due to some means which are implemented in Lithuania and they are: the conveyance of the society and manufacturers about the harm which the materials cause, about possible substitutes and about the requirements of the law acts of European Union and the national law acts. Most of these means were implemented with the help of irretrievable support of World environment funds. After the analysis of law acts and the statistics data it was defined that the hypothesis of the work have been... [to full text]

The way people view development is changing. The world now advocates for a development that also considers future generations. There is a paradigm shift towards sustainable development - a development in today's lifestyle without destroying the resources for tomorrow generations. Sustainable development is a broad concept that addresses how human activities impact on the economic, environmental and social well-being of an ecosystem; however, practical application of the sustainability concept is complex because its objective assessment is elusive. It is often said that the effect of technology on society has never been more profound than today. As mankind develops in science and technology to improve on his well-being, certain impacts are made on the systems that support human existence. Liquefied natural gas (LNG) technology, like gas-to-liquid (GTL) technology, is a latest innovation conceived to 'fight' the problem of gas flaring, and help contribute to the social and economic growth of the people; but it is necessary for man to know if these contemporary technologies are sustainable. This dissertation critically appraises the impact of the LNG project on the community of Bonny Island in Nigeria from a holistic perspective. The approach to the research work is three-fold: an appropriate sustainability framework is selected based on certain criteria; sustainability indicators are developed from the chosen framework; and the sustainability indicators are used to assess the impact of the project on the flora and fauna of the community. To have a clear picture of the impact of Nigeria LNG on its host community, Epe-Waterside is chosen as a control community because of its similar socio-geographical outlook to Bonny Island community. The control community is then subjected to the same set of sustainability indicators for a comparative analysis. The outcome of the research work shows that, though the economic and social conditions of Bonny Island seem much better, its environmental status remains a challenge. In other words, it can be concluded that the present approach to the operation of the LNG technology is not sustainable. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2009.

The way people view development is changing. The world now advocates for a development that also considers future generations. There is a paradigm shift towards sustainable development - a development in today's lifestyle without destroying the resources for tomorrow generations. Sustainable development is a broad concept that addresses how human activities impact on the economic, environmental and social well-being of an ecosystem; however, practical application of the sustainability concept is complex because its objective assessment is elusive. It is often said that the effect of technology on society has never been more profound than today. As mankind develops in science and technology to improve on his well-being, certain impacts are made on the systems that support human existence. Liquefied natural gas (LNG) technology, like gas-to-liquid (GTL) technology, is a latest innovation conceived to 'fight' the problem of gas flaring, and help contribute to the social and economic growth of the people; but it is necessary for man to know if these contemporary technologies are sustainable. This dissertation critically appraises the impact of the LNG project on the community of Bonny Island in Nigeria from a holistic perspective. The approach to the research work is three-fold: an appropriate sustainability framework is selected based on certain criteria; sustainability indicators are developed from the chosen framework; and the sustainability indicators are used to assess the impact of the project on the flora and fauna of the community. To have a clear picture of the impact of Nigeria LNG on its host community, Epe-Waterside is chosen as a control community because of its similar socio-geographical outlook to Bonny Island community. The control community is then subjected to the same set of sustainability indicators for a comparative analysis. The outcome of the research work shows that, though the economic and social conditions of Bonny Island seem much better, its environmental status remains a challenge. In other words, it can be concluded that the present approach to the operation of the LNG technology is not sustainable. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2009.