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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Noise and disturbance caused by vehicles crossing cattle grids: comparison of installations

Watts, Gregory R., Pheasant, Robert J., Khan, Amir 17 September 2016 (has links)
Yes / Cattle grids are used on roads and tracks to prevent grazing animals from leaving an open space without fencing onto a more controlled area where access to the road from surrounded land is more limited. They are widely used in the UK at the entrances to common and moorland areas where animals are free to roam, but also on private drive entrances. Typically, they consist of a series of metal bars across the road that are spaced so that an animal’s legs would fall through the gaps if it attempted to cross. Below the grid is a shallow pit that is intended to further deter livestock from using that particular crossing point. The sound produced as vehicles cross these devices is a characteristic low frequency “brrrr” where the dominant frequencies relates to the bar passage frequency under the tyres. The sound can be disturbing to riders and their horses and walkers and residents living close by as evidenced by press reports and the need to consider noise aspects in planning for new installations. For this reason and due to the lack of available information on the size and nature of the problem measurements and recordings have been made at a number of sites in Yorkshire in the UK. In addition, questionnaire surveys of residents living close by and façade measurements have also been used to gauge impact. Results show that there is a wide variation in the maximum noise level produced by cattle grids of apparently similar design. This can be related to impact noise produced by the movement of all or part of the grid as the frame comes under impulsive loading as the vehicle crosses. It was further established that some residents living close to the cattle grids were disturbed by the noise, and in some cases vibration, and wanted them removed or suitably modified. / The work was funded by the Bradford Centre for Sustainable Environments, University of Bradford.
2

Investigation of noise and disturbance from vehicles crossing cattle grids and examination of options for mitigation

Watts, Gregory R., Pheasant, Robert J., Khan, Amir 16 September 2016 (has links)
Yes / Cattle grids are used on roads and tracks to prevent grazing animals from leaving an open space without fencing onto a more controlled area where access to the road from surrounded land is more limited. They are widely used in the UK at the entrances to common and moorland areas where animals are free to roam, but also on private drive entrances. Typically, they consist of a series of metal bars across the road that are spaced so that an animal’s legs would fall through the gaps if it attempted to cross. Below the grid is a shallow pit that is intended to further deter livestock from using that particular crossing point. The sound produced as vehicles cross these devices is a characteristic low frequency “brrrr” where the dominant frequencies relates to the bar passage frequency under the tyres. The sound can be disturbing to riders and their horses and walkers and residents living close by as evidenced by press reports and the need to consider noise aspects in planning for new installations. For this reason and due to the lack of available information on the size and nature of the problem measurements and recordings have been made at a number of sites in Yorkshire in the UK. In addition, questionnaire surveys of residents living close by and façade measurements have also been used to gauge impact. Results show that there is a wide variation in the maximum noise level produced by cattle grids of apparently similar design. This can be related to impact noise produced by the movement of all or part of the grid as the frame comes under impulsive loading as the vehicle crosses. It was further established that some residents living close to the cattle grids were disturbed by the noise, and in some cases vibration, and wanted them removed or suitably modified. Means of reducing the problem are proposed.
3

Noise impact - a liveable or unbearable disturbance - A case study in noise impact during the construction phase of Citybanan and Norra länken. / Bullerpåverkan - uthärdlig eller outhärdlig störning. En fallstudie om bullerpåverkan under konstruktionsfasen av Citybanan och Norra länken.

Strömberg, Caisa January 2011 (has links)
Noise is today defined as an unwanted sound that invades the lives of many people in their homes and at work. During a construction phase a large amount of noise is generated that often leads to community complaints. The construction business has to face this issue today when larger infrastructure projects are performed in highly dense areas. Therefore the aim of this Master’s Thesis is to investigate the effect construction noise has on humans and the perceived annoyance in the concerned studied areas, which Bilfinger Berger is contractor for. The impact was studied on both the third party around a construction site on Södermalm, Stockholm and on Bilfinger Berger’s employees on the site. The work concerns three areas, which are situated in the inner city of Stockholm and represent contracts of the infrastructure pro-jects Citybanan and Norra länken. The extensive noise emission during an infrastructure project is affecting the surrounding environment both due to the high noise level that is generated from a number of machines and work activities. Also due to the extensive time frame a project of this kind has. Therefore it is a complex problem to handle and essential for both contractor and client to handle properly. By using appropriate mitigation measures through both the planning stage, the construction phase and clear information towards all parties the impact can be reduced. Through a literature study among the existing science and observations of which mitigation measures are used today to reduce the noise level on sites, a base of theoretical knowledge could be built up for this study. The real noise impact among the affected parties was performed through a survey, which gave results that could be evaluated and discussed. The results from the surveys show that the third party around the workplace is definitely affected by the noise generated from the production. It is also possible to assume that the most affected are persons, which spend a lot of the daytime at home, and therefore feels the noise very disturbing and has to adapt their life after the project’s progress. Through the survey among the employees at Bilfinger Berger a certain acceptance exist towards the noise even if they feel disturbed by the noise. The conclusion drawn from this is that the human attitude to noise impact becomes more positive if they have the knowledge about why and how it arises even if the noise has the same impact on everyone. Therefore the noise issue has to be raised in future projects, even during the tender phase when noise is always easier to control in an earlier stage.
4

ESTUDO DE TIPOLOGIAS DE LAJES QUANTO AO ISOLAMENTO AO RUÍDO DE IMPACTO / STUDY OF TYPOLOGIES OF FLOOR-SUPPORT IN REGARD TO ISOLATION OF NOISE IMPACT

Pereyron, Daniel 24 October 2008 (has links)
The current research focuses on the environmental comfort in the civil construction and refers to a comparative analysis related to the acoustic isolation of reinforced concrete pavement which is submitted to noise of impact. According to thestandards ISO-140/VII, the measurements were taken in situ by using appropriate equipment for this purpose. In order to achieve the aims of this dissertation, unfinished constructions which used different typologies of floor-support (slab) in their structural system were chosen as the object of measurement and, this way, uncovered slabs could be measured. Therefore a better evaluation of their performance was possible and the sound isolation was related to the impact noise, providing evidence of the acoustic isolation. The analysis and interpretation of the results were undertaken through tables and graphs that, according to ISO 717-2, show the performance of each slab and a possible comparison among them. This is also a contributing factor to civil construction professionals as being a working instrument and it serves as a data base for a better understanding towards these materials performance. In this way, minimal values of acoustic comfort may be estimated in a near future. / A presente pesquisa concentra-se na área de conforto ambiental na construção civil e refere-se a uma análise comparativa quanto ao desempenho do isolamento acústico de tipologias de lajes submetidas a ruído de impacto. Os ensaios foram realizados in situ , em conformidade com as normas da ISO-140/VII, utilizando equipamentos adequados para este fim. Para o desenvolvimento desta dissertação, escolheram-se como objetos de medição obras ainda em fase de construção que tivessem utilizado como sistema estrutural as lajes maciça, nervurada, pré-moldada convencional e pré-moldada treliçada, possibilitando assim a medição das lajes em osso , ou seja, sem o revestimento de piso. Dessa forma, foi permitida uma melhor avaliação do desempenho dessas, relacionando o isolamento sonoro ao ruído de impacto, evidenciando assim o desempenho acústico deste sistema. A análise e interpretação dos resultados foram realizadas através de tabelas e gráficos que, de acordo com a ISO 717-2, demonstram o desempenho de cada laje, permitindo-nos assim traçar um comparativo entre essas, o que contribui como ferramenta de trabalho para os profissionais da construção civil e serve como base de dados para um melhor conhecimento do desempenho destes materiais. Desse modo, valores mínimos de conforto acústico ao usuário da construção civil podem vir a serem traçados futuramente.
5

Noise Pollution/Reduction Education for Frontline Staff in the Acute Care Setting

Patel, Lopa 01 January 2019 (has links)
Noise levels in hospital settings have risen beyond the recommended range of 35-40 decibels, resulting in poor patient healing outcomes and other health conditions ranging from sleep deprivation, anxiety, agitation, delirium, depression, and high heart rate and blood pressure. These negative patient health experiences are evidenced by poor scores for the Hospital Consumer Assessment of Healthcare Providers and Systems, which are indicators of patients' perceptions of care. This project explored whether an educational activity for 48 direct care staff, who include registered nurses and nursing assistants, in a cardiac unit on the impact of noise pollution on patient healing would increase staff members' knowledge of interventions to reduce noise pollution. The information processing theory guided this project. Eighty-nine percent of the participants strongly agreed that the educational activity was relevant to their practice as health care providers on the cardiac monitored unit. All participants strongly agreed that they would be able to identify when the unit was noisy and when noise was impacting a patient both physiologically and psychologically. Participants indicated that they could implement the suggested behavioral modifications to promote a healing environment. Participants strongly agreed that the speaker was effective in communicating the importance of noise pollution and its impact on patient healing and ways in which to combat the problem (89%), and they were generally satisfied with the learning activity (91%). Reducing noise pollution might create a healing environment for cardiac patients, thus positively impacting patient satisfaction and well-being.
6

Automagistralių transporto keliamo triukšmo poveikio sveikatai ir gyvenimo kokybei valdymas Lietuvoje / Management of motorway transport–generated noise impact on health and quality of life in Lithuania

Chmieliauskienė, Žibutė 16 June 2005 (has links)
SUMMARY Public Health Management MANAGEMENT OF MOTORWAY TRANSPORT–GENERATED NOISE IMPACT ON HEALTH AND QUALITY OF LIFE IN LITHUANIA Žibutė Chmieliauskienė Scientific work supervisor Prof., Dr. Habil. Žilvinas Padaiga Kaunas University of Medicine, Faculty of Public Health, Department of Social Medicine. Kaunas, 2005.- 100p. Aim of the study – to investigate the process of managing transport-generated noise impact on human health and quality of life in Lithuania. Objectives: 1) to generalize investigations of managing motorway transport-generated noise identification, impact on human health and quality of life, 2) to assess the impact of the motorway AI Vilnius- Kaunas on the health of local residents and the effects on quality of life, 3) to give recommendations for the management and control of motorway-generated noise. Expected results: Justification of the management of transport-generated noise impact on human health. Methods of investigation. In order to assess motorway transport-generated noise impact on human health and quality of life the motorway AI (IX B) Vilnius – Kaunas was selected and the neighboring residential farmsteads. In each noise level zone at the interval of 5 dBA the residential farmsteads were identified: 1) respondents, living within the zone of the increased traffic noise ≥55dBA (in a day time), and 2) respondents, living within the zone of permissible traffic noise <55dBA (control group). The questionnaire inquiry was carried out, the total... [to full text]
7

Transporto priemonių keliamo triukšmo valdymo politika / Management policy of transport generating noise

Petrauskaitė, Vaida 04 January 2007 (has links)
Transport Noise is an urgent and still unsolved environmental problem not only in Lithuania but also in the world over. The most common noise sources in the environment are traffic noise: road, rail and aircraft. In June 2002, the Commission issued a proposal for a European Directive on the assessment and management of environmental noise. The aim of this Directive shall be to define a common approach intended to avoid, prevent or reduce on a prioritised basis the harmful effects, including annoyance, due to exposure to environmental noise, to make noise maps for agglomerations, major roads, major railways and airports. A law on Noise Management and Higiene Standard HN 33-1:2003. Acoustic noise. Allowed levels in residented and work premises. was adopted in order to meet the requirements and implement European Directive on the assessment and management of environmental noise. Aim of the study – to investigate transport generating noise impact and to analyses traffic noise reduction policy. Objectives: 1) in order to annotate the topical of choisen method was needed to outspread noise conception and to separate out models acoording to theirs preeminence on purpose to reduce transportation noise; 2) to investigate and compare the features of Noise regulations, leading management programs and attendat legal acts of Member States of the European Union; 3) to assess the main sources of noise emissions and to estimate transportation noise impact to the environmental components... [to full text]
8

Vliv režimu práce motoru mobilních energetických prostředků na hladinu akustického tlaku / Impact of motor operation mode of mobile power vehicles on level of acoustic pressure

KLEČACKÝ, Ondřej January 2015 (has links)
The diploma thesis is focused on analysis of noise level of mobile power vehicles in relation to motor operation mode and its evaluation. The thesis core lies within measurement of acoustic pressure levels at four vehicles in different motor operation modes by two audio-noise meters. One meter was places within the cabin, the other outside. The results of the work showed a development in reducing noise at modern power vehicles.
9

Estimation of Ship Properties for Energy Efficient Automation

Nilsson, Lucas January 2016 (has links)
One method to increase efficiency, robustness and accuracy of automatic control, is to introduce mathematical models of the system in question to increase performance. With these models, it is possible to predict the behavior of the system, which enables control according to the predictions. The problem here is that if these models do not describe the dynamics of the system well enough, this method could fail to increase performance. To address this problem, one idea is to estimate the dynamics of the system during operation, using methods for system identification, signal processing and sensor fusion. In this thesis, the possibilities of estimating a ship's dynamics during operation have been investigated. The mathematical model describing the dynamics of the ship is a graybox model, which is based on the physical and mechanical relations. This model's properties are therefore described by physical quantities such as mass and moment of inertia, all of which are unknown. This means that, when estimating the model, these physical properties will be estimated. For a systematic approach, first a simulation environment with a 4-degrees-of-freedom ship model has been developed. This environment has been used for validation of system identification methods. A model of a podded propulsion system has also been derived and validated. The methods for estimating the properties of the ship have been analyzed using the data collected from the simulations. For system identification and estimation of ship properties, the influence of measurement noise and potential of detecting a change in dynamics has been analyzed. This has been done through Monte Carlo simulations of the estimation method with different noise realizations in the simulations, to analyze how the measurement noise affects the variance and bias for the estimates. The results show that variance and bias vary a lot between the parameters and that even a small change in dynamics is visible in some parameter estimates when only ten minutes of data have been used. A method based on cumulative summation (CUSUM) has been proposed and validated to analyze if such a method could yield fast and effective detection of system deviations. The results show that the method is rather effective a with robust detection of changes in the dynamics after about four minutes of data collection. Finally, the methods have been validated on data collected on a real ship to analyze the potential of the methods under actual circumstances. The results show that the particular data is not appropriate for this kind of application along with some additional problems that can yield impaired results. / Genom att inkludera matematiska modeller som beskriver ett systems dynamik i styrningsalgoritmer, kan man åstadkomma en automatisk styrning med förbättrad effektivitet, robusthet och noggrannhet. Med dessa modeller går det att förutsäga beteendet hos systemet och därmed öppnas också möjligheten att använda sig av detta i styrningen. Problemet är att om dessa modeller inte beskriver systemets dynamik tillräckligt bra kan prestandan istället sänkas genom dessa metoder. Den här sortens problem kan man lösa genom att aktivt skatta systemets dynamik under körning, med hjälp av metoder för systemidentifiering, signalbehandling och sensorfusion. I denna exjobbsrapport har möjligheterna att skatta ett skepps girdynamik undersökts. Den matematiska modell som beskriver skeppets dynamik är en grålådemodell som baserar sig på fysikaliska och mekaniska samband. Denna modells egenskaper beskrivs därför av fysikaliska storheter så som massa, tröghetsmoment och tyngdpunkt, vilka alla är okända. Detta innebär att vid modellskattning skattas dessa fysikaliska storheter, vilka kan vara av stort intresse. En simuleringsmiljö med en skeppsmodell med fyra frihetsgrader har skapats och använts för att validera metoder för systemidentifiering. En modell av ett roterbart framdrivningssystem har också härletts och inkluderats i simuleringsmodellen. Vid systemidentifiering och skattning av skeppets egenskaper har dels inverkan av mätbrus analyserats samt även möjligheter till att detektera skillnader i dynamik. Detta har gjorts med Monte Carlo-simuleringar av skattningsmetoden med olika brusrealiseringar för att analysera hur mätbrus påverkar variansen och metodfelet hos skattningarna. Resultaten visar att vissa parametrar skattas med större noggrannhet och hos dessa kan därmed en förändring i dynamik identifieras när endast tio minuter av data har använts. En metod baserad på kumulativ summering av residualer har formulerats och validerats, detta för att undersöka om en sådan metod kan ge snabb och effektiv detektion av systemförändringar. Resultat visar på robusthet i att detektera skillnader i dynamik efter ungefär fyra minuter av datainsamling. Slutligen har metoderna validerats på data insamlad på ett riktigt skepp för att undersöka potentialen under verkliga omständigheter. Resultaten visar att just denna data inte är lämplig för denna applikation samt några problem som kan leda till försämrade resultat.

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