Nightclubs and restaurant bars have become major sources of noise pollution particularly in areas close to residential dwellings. The purpose of this study was to investigate the impact of noise emanating from nightclubs and restaurant bars on the community of Melville, Johannesburg. This study followed both qualitative and quantitative research methods. A total of 100 respondents were randomly sampled within the study area. Qualitative data was collected using a structured questionnaire. A calibrated sound level meter was used to measure environmental noise levels at 10 different measuring points. The research finding revealed that about:  87% of noise levels measured with the sound level meter did not comply with officially acceptable levels of 40dB at night.  69% of respondents indicated that the main source of noise is pollution is nightclubs.  78% of respondents described noise as annoying, disturbing and unwanted.  57% of respondents indicated that members of their household have suffered from sleeping disorders due to noise activities at night disrupting their sleep patterns and resulting in irritability and fatigue. The noise measurements were taken on weekends and public holidays during the day from 10h00 to 14h30 and at night from 22h00 to 02h30. The research findings revealed that the residents of Melville experienced high level of noise at night with nightclub as major source of noise and as a result the majority of the sampled population complained about irritability, fatigue and sleeping disorders due to exposure to noise. The outcome of this research indicated the need of health education on the adverse effects of noise pollution and the need of sound insulation at places of entertainment. Implementation of a noise management policy is needed in order to effectively control and manage the noise pollution in its area of jurisdiction and regular noise level monitoring by constantly taking noise measurements by law enforcements officers. / Department of Environmental Sciences / M. Sc. (Environmental Management)

L’analyse vibratoire constitue une part très importante des moyens de mesures pour la surveillance et la détection des défauts mécaniques des machines tournantes. Le positionnement des accéléromètres est stratégique et contribue fortement à la réussite du diagnostic ; la proximité du capteur de l’élément défaillant est une condition très utile, mais pas toujours réalisable. La corrélation entre le bruit émis par une machine et son état est assez étroite et montre l’apport des mesures acoustiques pour l’optimisation du diagnostic. L’imagerie acoustique, très appliquée pour détecter des sources dans le domaine du transport, avec ses multiples méthodes (holographie, beamforming, etc…) peut être un moyen pour remonter aux défauts mécaniques. Dans cet objectif, plusieurs stratégies basées sur l’algorithme de beamforming sont développées. Premièrement, des indicateurs communément utilisés pour le diagnostic des machines sont visualisés en fonction de l’espace. Le kurtosis permet de localiser les sources impulsives qui peuvent être reliées à un défaut. De nouveaux indicateurs basés sur le spectre d’enveloppe des signaux focalisés sont également mis en place pour détecter les défauts de roulement de bague interne et externe. D’autre part, la moyenne synchrone angulaire est utilisée pour extraire le champ acoustique synchrone avec la rotation d'un composant de la machine. Les sources reliées à un défaut sont affectées au champ résiduel et peuvent être identifiées dans les cartographies. Enfin, une nouvelle méthode d'imagerie acoustique qui exploite les fonctions de transfert vibroacoustiques entre des accéléromètres positionnés sur la machine et une antenne acoustique est développée. Elle permet d'obtenir des cartographies de la pression rayonnée sur une surface de la machine uniquement à partir d'accéléromètres. Son applicabilité à la détection de défaut est également démontrée sur un banc à engrenages. / Vibration analysis is mainly used in condition monitoring and fault detection of rotating machine domain. The success of the diagnosis is strongly related to the position of the accelerometers. However, the machine geometry sometimes prevents the sensors to be placed close enough to the faulted part causing the diagnostic failure. The sound emitted by a mechanism and its condition are related. Using microphones to optimize condition monitoring is then justified. Acoustic imaging techniques (acoustic holography, beamforming, etc…) are mainly used as a source localization and quantification tool but they can be turned into a powerful diagnosis tool. Several strategies based on the beamforming algorithm are developed in this work. Firstly, diagnosis features commonly used in condition monitoring of rotating machinery are mapped as a function of space. Kurtosis allows localizing impulsive sources which eventually can be related to a mechanism failure. New features based on the squared envelope spectrum of the focused signals are also introduced. They aim toward the detection of inner and outer race fault in roller element bearings. On the other hand, angular synchronous average is used to extract the acoustic field synchronous with one component rotation. The sources related to a fault are localized in the residual field mappings. Finally, a new imaging technique based on the vibroacoustic transfer functions between a few accelerometers placed on the machine and the microphone array is developed. It allows obtaining the mappings of the radiated pressure on the machine surface only thanks to the accelerometers. It is tested as a fault detection tool on a test bench

Annoyance due to relatively high levels of sound and noise, above 50 dB, has been well documented in noise assessment literature. The potential for annoyance or disturbance from low amplitude sound, below 50 dB to the threshold of an individual’s hearing, is not as well documented. The thesis presents a new approach to the measurement and assessment of intrusive noise and low amplitude sound. Acoustical and sound quality measures are integrated with measures of loudness, pitch, dissonance and tonality to provide physical measures of sound. Individual amenity is assessed with respect to personal noise sensitivity and personal attitudes to sound in the environment, the environment itself and the perceived qualities of the audible sound. A decision-support methodology to integrate perceived noise with noise performance indicators, annoyance criteria, personal noise sensitivity and amenity is presented. A method for rating intrusive noise is derived. Designs for sound measurement and calibration instrumentation are described. Methods to measure and assess low amplitude sound are presented. Keywords annoyance, intrusive-noise, noise-sensitivity, sound-quality, soundscape

Thesis (M.Com. (Economics))--North-West University, Vaal Triangle Campus, 2006.

This dissertation studies the social cost of pollution in Leitrirn, which is a township in the Vaal Triangle area. Policies and technologies that may be implemented to reduce pollution inc poor communities are also discussed. The study focuses on three areas namely pollution unemployment and poverty. Leitrim experiences a high rate of both unemployment and poverty. Residents in this area also experience high levels of pollution. Compared to Rathanda township which is more rural. Leitrim is worse off in terms of unemployment poverty and pollution. Unemployment is a major determinant of povert in Leitrim. The main component of a policy aimed at alleviating poverty in Leitrim should therefore focus on employment creation. Unemployment and poverty are defined and measured in this dissertation and the poor in Leitrim are profiled in terms of their gender qualification employment, unemployment and their spending methods. For measuring poverty the Household Subsistence Level (HSL) is used as poverty line to determine the headcount index and the poverty gap. Pollution is identified as one the factors which affect the wellbeing of the poor negatively. Reducing the k\el pollution will therefore also reduce the depth of poverty in poor communities. This dissertation focuses on the following types of pollution: land-based pollution (littering), dust pollution, noise pollution and air (indoor smoke pollution & air pollution from coal fire) pollution. Alternative technologies such as BM implemented in full scale can reduce the level of air pollution by more that 50 percent. It will also reduce the monthly household expenditure of poor households on coal by at least J.5 percent. / Thesis (M.Com. (Economics))--North-West University, Vaal Triangle Campus, 2006.

This dissertation studies the social cost of pollution in Leitrirn, which is a township in the Vaal Triangle area. Policies and technologies that may be implemented to reduce pollution inc poor communities are also discussed. The study focuses on three areas namely pollution unemployment and poverty. Leitrim experiences a high rate of both unemployment and poverty. Residents in this area also experience high levels of pollution. Compared to Rathanda township which is more rural. Leitrim is worse off in terms of unemployment poverty and pollution. Unemployment is a major determinant of povert in Leitrim. The main component of a policy aimed at alleviating poverty in Leitrim should therefore focus on employment creation. Unemployment and poverty are defined and measured in this dissertation and the poor in Leitrim are profiled in terms of their gender qualification employment, unemployment and their spending methods. For measuring poverty the Household Subsistence Level (HSL) is used as poverty line to determine the headcount index and the poverty gap. Pollution is identified as one the factors which affect the wellbeing of the poor negatively. Reducing the k\el pollution will therefore also reduce the depth of poverty in poor communities. This dissertation focuses on the following types of pollution: land-based pollution (littering), dust pollution, noise pollution and air (indoor smoke pollution & air pollution from coal fire) pollution. Alternative technologies such as BM implemented in full scale can reduce the level of air pollution by more that 50 percent. It will also reduce the monthly household expenditure of poor households on coal by at least J.5 percent. / Thesis (M.Com. (Economics))--North-West University, Vaal Triangle Campus, 2006.

Carbon dioxide is one of the greenhouse gases which have strong impacts on the environment and its amount in the atmosphere is far beyond to be ignored. Carbon dioxide levels are projected to be reduced by sequestering it directly to the underground. High amounts of carbon dioxide can be safely stored in underground media for very long time periods. Storage in depleted gas reservoirs provides an option for sequestering carbon dioxide. In 2002, production of Kuzey Marmara gas reservoir has been stopped due to gas storage plans. Carbon dioxide sequestration in Kuzey Marmara field has been considered in this study as an alternative to the gas storage projects. Reservoir porosity and permeability maps were prepared with the help of Surfer software demo version. These maps were merged with the available Kuzey Marmara production information to create an input file for CMG-GEM simulator and a three dimensional model of the reservoir was created. History match of the field model was made according to the 1998-2002 production data to verify the similarity between the model and actual reservoir. Kuzey Marmara field is regarded as a candidate for future gas storage projects. The reservoir still contains producible natural gas. Four different scenarios were prepared by considering this fact with variations in the regional field properties and implemented into previously built simulation model. These scenarios primarily focus on sequestering carbon dioxide while producing as much as natural gas possible. After analyzing the results from the scenarios it is realized that / CO2 injection can be applied to increase natural gas recovery of Kuzey Marmara field but sequestering high rate CO2 emissions is found out to be inappropriate.

Orientador: Stelamaris Rolla Bertoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-05T23:46:28Z (GMT). No. of bitstreams: 1 Santos_Christiandos_M.pdf: 3511506 bytes, checksum: d365f6dc71d5566b93533834923018e0 (MD5) Previous issue date: 2004 / Resumo: A existência de fenômenos acústicos depende de três fatores: a fonte, o meio e o receptor. Para a prevenção de condições ruidosas em certos ambientes, é necessário o conhecimento de uma característica própria da fonte que não sofre interferência do meio na propagação da energia sonora, como é o caso da potência sonora. O IBAMA em conjunto com o INMETRO iniciou um programa que visa informar e minimizar o ruído (nível de potência sonora) produzido por aparelhos elétricos etiquetando-os. Este programa se chama Selo Ruído. Existe uma previsão de inclusão de ferramentas elétricas neste programa de etiquetagem. A furadeira elétrica é uma destas ferramentas que tem inclusão prevista. Com o intuito de investigar os métodos de ensaio para determinação de potência sonora, este trabalho propõe a realização de ensaios de diversos métodos normalizados de determinação de nível de potencia sonora aplicando-os para furadeiras elétricas. Os métodos escolhidos para os ensaios foram os que utilizam salas reverberantes especiais (ISO 3743 ¿ Engineering Methods for Special Reverberations test Rooms e ISO 3741 ¿ Precision Methods for Special Reverberations test Rooms). Estes métodos são referenciados na norma nacional NBR 13910:1997-Parte 1- Diretrizes de ensaios para a determinação de ruído acústico de aparelhos eletrodomésticos e similares. Com os resultados obtidos dos ensaios realizados, foi feita uma análise de qualificação das metodologias empregadas. A partir de cada item destas metodologias foi analisada a aplicabilidade destes itens a ser empregado no método de ensaio proposto. A construção das etapas do método foi obtida a partir dos itens qualificados e aplicáveis ao programa de etiquetagem Selo Ruído / Abstract: In the acoustic phenomena there are three main variables: the source, the medium and the receptor. For the prevention of noise conditions in certain places, it is necessary to know a source characteristic that does not change with medium variations. This characteristic is the sound power radiated by the source. To consider this prevention, IBAMA and INMETRO started a program that labels the household appliances according to the noise level emitted by them. This program is called ¿Selo Ruído¿. There is a prevision to include the electric tools in this label program. The drill is one of these electric tools that will be included. To investigate the methods for determination of the sound power levels, this work proposes some tests of drills in several standarded methods. The methods used for the tests were the ones that use reverberation rooms (ISO 3743 ¿ Engineering Methods for Special Reverberations test Rooms and ISO 3741 ¿ Precision Methods for Special Reverberations test Rooms). These methods are referenced at the Brazilian standard NBR 13910:1997 ¿ Part 1 ¿ ¿Diretrizes de ensaios para a determinação de ruído acústico de aparelhos eletrodomésticos e similares¿. A qualification analysis of the methodologies applied was done, based on the tests results. An application of these items was done from each item of these methodologies in the test method proposed. The construction of the steps in the proposed method was made from the items qualified and applied to the ¿Selo Ruído¿ program / Mestrado / Edificações / Mestre em Engenharia Civil

M.Sc. (Environmental Management) / Any change in land-use goes hand-in-hand with changes in the prevailing ambient conditions such as a change in the prevailing environmental noise and ground vibration levels. This increase may have an impact on the health and well-being of people and may furthermore result in structural damage to houses. The level of exposure will depend on the type of activity, distance from the source and the attitude of the people exposed to the land-change activities. The main objective of this research was to identify, compare and determine what the impact of mine establishment could have on a residential area some 900m from the mine footprint area. The results of the survey would assist management in employing engineering control measures which would control the exposure levels. Mines are generally established in frontier regions where there are already formal and informal residential areas. These residential areas are usually in rural districts with low prevailing ambient noise levels or, if in fact perceptible, insignificant ones at the most. This study dealt with the evaluation of physical aspects such as environmental noise and ground vibration levels and the determination of exposure levels, an issue of environmental impact and of concern to public health. The village which is being exposed to increased noise and ground vibration levels is a formal housing area with infrastructural components such as roads, water and electricity connections. The exposure levels before and during the construction phase gave an indication of the positive or negative exposure levels that the people were enduring during the establishment phase of the mine...

Noise pollution is widespread in today’s society, from traffic to industrial sources, and many people are confined to unhealthy acoustic environments through their employment. When noise cannot be eliminated at the sound source, the protective measure is usually to equip the employee with hearing protection devices (HPDs), e.g. earmuffs, that attenuates the noise. Applying excessive attenuation can render the wearer disconnected from her acoustic environment and present risks and social isolation. HPDs using level-dependent function (LDF) uses ambient microphones together with a signal processing unit and internal loudspeakers to achieve attenuation flexibility – if ambient noise is low, the loudspeakers can amplify the sound to combat an excessive passive attenuation of the HPD, and if ambient noise is high this amplification is decreased to maintain healthy sound levels. Appropriate levels of attenuation allows the user to detect ambient sounds which contributes to the their situational awareness. Besides attenuating the sounds however, HPDs does change the spectral content of the sound which may complicate the ability to identify them. This thesis has focused on exploring the human ability to identify sounds, design a method for measuring this ability, implement it and evaluate its result and the method itself. The thesis has been conducted in collaboration with 3MTM PeltorTM and was intended to evaluate the effect of earmuffs with LDF on the ability to identify sounds in a process industry soundscape. The progression of the thesis was structured within the Double Diamond process, where literature reviews, benchmarking and workshops informed the research and resulted in a method design that was analyzed using a repeated measures ANOVA based on empirical data from 16 participants. Surprisingly, the results showed no statistically significant advantage from wearing a HPD using LDF, as opposed to no LDF, in the user accuracy or certainty in sound identification. The reasons for this are discussed with a focus on evaluating the usefulness of the designed method in future efforts to develop HPDs that afford reliable sound identification. / Bullerföroreningar är ett utbrett problem i dagens samhälle, från trafik till industriella källor, och många människor är låsta till en ohälsosam akustisk miljö via sin anställning. När buller inte kan elimineras vid ljudkällan är skyddsåtgärden vanligtvis att förse arbetstagaren med hörselskydd, exempelvis hörselkåpor, som dämpar bullret. Att använda en överdriven dämpning kan dock göra att användaren avskiljs helt från sin akustiska miljö och innebära risker samt social isolering. Hörselskydd utrustade med nivåberoende funktion (LDF) använder mikrofoner tillsammans med en signalbehandlingsenhet och interna högtalare för att uppnå flexibilitet i dämpningen – om omgivande buller är lågt kan högtalarna förstärka ljudet för att motverka en överdriven passiv dämpning erbjuden av hörselskyddet, om omgivande buller däremot är högt kan denna förstärkning minskas för att vidhålla sunda ljudnivåer. Lämpliga dämpningsnivåer gör att användaren kan upptäcka omgivande ljud som bidrar till deras situationsmedvetenhet. Förutom att dämpa ljuden så ändrar dock hörselskydd också det spektrala innehållet i ljudet vilket kan komplicera förmågan att identifiera ljuden. Denna masteruppsats har fokuserat på att utforska människans förmåga att identifiera ljud, utforma en metod för att mäta denna förmåga, implementera metoden och utvärdera dess resultat samt metoden i sig. Uppsatsen har genomförts i samarbete med 3MTM PeltorTM och var avsedd att utvärdera effekten av hörselkåpor, utrustade med LDF, på förmågan att identifiera ljud i ett ljudlandskap likt det i en processindustri. Projektet var strukturerad enligt Double Diamondprocessen, där litteraturstudier, benchmarking och workshops har informerat och väglett arbetet och resulterat i en metod som analyserats med hjälp av variansanalys baserat på empiriska data från 16 deltagare. Överraskande nog så visade resultaten ingen statistiskt signifikant fördel med att bära ett hörselskydd som är utrustat med LDF till skillnad från ett hörselskydd som saknar denna funktion, vad gäller användarens förmåga att korrekt identifiera ljud samt rapporterad säkerhet i svaren. Orsaker till detta diskuteras med fokus på att utvärdera användbarheten av den utformade metoden i framtida ansträngningar för att utveckla hörselskydd som erbjuder tillförlitlig ljudidentifiering.