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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

En kvalitativ och kvalitativ studie om hur pedagoger upplever och resonerar om ljudnivån i förskolan / A qualitative and quantitative study of how teachers perceive and reason about the noiselevel in preschool

Mohlén, Priya, Broo, Annette, Karlsson, Anneli January 2013 (has links)
Studien belyste pedagogers upplevelser av ljudmiljön i förskolan samt hur de säger sig planera och organisera den pedagogiska verksamheten för att främja en god ljudmiljö. Studien var angelägen på det vis att det är viktigt att pedagoger inkluderar ljudmiljön i verksamheten och ser till att den inte utgör ett hinder för barns lärande och utveckling. En medvetenhet om det pedagogiska uppdraget är en viktig del, så att barn och pedagoger inte exponeras för skadligt ljud mer än nödvändigt. Förskolan ska erbjuda barnen en verksamhet där barn och pedagoger trivs och mår bra tillsammans. Därför är det betydelsefullt att arbetet kring ljudmiljön hålls levande. Utifrån studiens syfte valde vi att genomföra en empirisk undersökning, med hjälp av enkät och intervju. De två teoretiska utgångspunkterna för studien var det miljöpsykologiska perspektivet, som avser att beskriva hur individen påverkas av och påverkar miljön. Denna påverkan är individuell. Den andra teorin som valdes var den sociokulturella, som förklarar lärande som något som sker i ett socialt och kulturellt sammanhang. Resultatet visade att pedagoger upplever en hög ljudnivå i förskolan och att de påverkas negativt av den, såväl fysiskt som psykiskt. Resultatet visade även att pedagoger säger sig inkludera ljudnivån när de planerar och organiserar verksamheten. Utifrån vad pedagogerna säger har tre perspektiv urskilts såsom: pedagogens roll, barnet som medaktör och rummet som verktyg. I diskussionen behandlas konsekvenser av exponeringen av en hög ljudnivå och hur den kan påverka barns utveckling och lärande. Diskussionen belyser även det pedagogiska uppdraget utifrån den yttre och inre organisationen. / This study strives, firstly, to make the reader aware of how preschool teachers experience the noise level in preschools. Secondly, the study accounts for how the mentioned teachers express how they plan and organize the school activities in accordance to the sound environment. This subject is important because noise can interrupt the children’s development and learning. The teachers ought to be aware of their teaching assignment, so that neither children nor teachers are exposed to more noise than necessary. The preschool must provide a school environment where both children and teachers are comfortable and feeling well when being together. Therefore must there be a continuance in the work to keep the noise to a minimal level. In accordance with the aim of this study we have taken advantage of an empirical study, with the help of a survey and an interview. There were two theoretical starting points; the first was the perspective of environmental psychology which strives to describe how the individual is affected by and affects the environment. The second starting point was the social cultural perspective, which focuses on how individuals develop in social and cultural relationships. The result of the study clearly showed that the teachers experience a high noise level which affects them negatively, physically as well as psychologically, even though they express that they include the noise level as a factor when planning activities. Based on what the teachers express, three perspectives could be found such as; the teacher´s role, the co-operating child´s role and the organization of the environment. Finally, the consequences of exposing children for a high noise level are discussed. The discussion also highlights the educational mission by the external and internal organization.
2

Optimalizace vrtulí pro bezpilotní prostředky s uvážením hlučnosti / Noise reduction oriented optimization of UAV propellers

Ecler, Matěj January 2020 (has links)
This diploma thesis deals with optimization of propellers with the aim to reduce their noise level. Based on the measurement of noise level of serial propellers, major propeller noise sources were evaluated. Subsequent 2D simulations of the flow on the individual profiles along the propeller span revealed the locations of separation bubbles, which were identified as a potential source of the noise. Based on these findings, propellers were equipped with turbulator trips of various dimensions and their effect on the noise level and efficiency of the propellers was experimentally verified. The results did not show contribution of turbulator trips to noise reduction or efficiency.
3

AN INVESTIGATION OF CLASSROOM ACOUSTICS IN BUILDINGS CONSTRUCTED IN DIFFERENT ERAS OF THE 20TH CENTURY

BELAND, MICHELLE LYNNE 30 June 2003 (has links)
No description available.
4

Autotransporto triukšmo tyrimai Kėdaniuose / Motor noise Kedainiai

Gailiūnaitė, Ernesta 03 September 2010 (has links)
Autotransportas yra pagrindinis miesto triukšmo šaltinis. Didėjant automobilizacijai, didėja ir triukšmo lygis. Leistinieji triukšmo lygiai viršijami ne tik miesto centre, bet ir miesto viešosiose tyliosiose zonose, mokyklų, darželių – lopšelių, gyvenamųjų namų teritorijose. Dėl šių priežasčių yra trikdomas poilsis ir kenkiama sveikatai. Atliekant autotransporto triukšmo tyrimus Kėdainių mieste pasirinkta 16 vietų: mokyklų, darželių – lopšelių, viešųjų tyliųjų miesto zonų, parkų, ligoninės, gyvenamųjų namų teritorijose. Lyginant su higienos norma gauti rezultatai, leidžiantys parašyti išvadas ir pateikti pasiūlymus triukšmo mažinimui. Mažinant autotransporto triukšmo sklaidą Kėdainių mieste būtina taikyti prevencines ir triukšmo mažinimo priemones. Mažinti automobilių kiekį mieste, įrengti dviračių ir pėsčiųjų trasas, dažniau naudotis viešuoju transportu. / Transport is a major source of urban noise. Automobilization increases, and increases the noise level. The permissible noise levels are exceeded, not only downtown, but quiet in public and urban areas, schools and nurseries - Nursery school and residential areas. For those reasons, interfere with recreation and detrimental to health. The road noise in Kedainiai selected 16 places: schools, nursery - Nursery school, public dormant urban areas, parks, hospitals, residential areas. Compared with the hygiene rule, the results obtained allow to write the findings and suggestions for noise reduction. Reducing motor noise in the dissemination of Kedainiai need for preventive measures and noise reduction. Reduce the amount of parking in the city, equipped with bicycle and pedestrian trails, a greater use of public transport.
5

Bešvaistiklio stūmoklinio mechanizmo tyrimai / Research of crank less piston mechanism

Burneika, Benas, Janulytė, Živilė, Janulytė, Živilė 10 June 2011 (has links)
Baigiamajame magistro darbe yra pateikti bešvaistiklio eksperimentinio kompresoriaus triukšmo lygio, vibracinio aktyvumo, elektros energijos sąnaudų, našumo tyrimų rezultatai. Tyrimams atlikti buvo suprojektuotas ir sukonstruotas specialus tyrimų stendas bei sudarytos tyrimų metodikos, parinkta tyrimų įranga. Eksperimentai buvo atliekami, esant skirtingiems kompresoriaus sukimosi greičiams ir keičiant slėgį, suspausto oro sistemoje. Triukšmo tyrimai buvo atlikti keliuose skirtinguose matavimo taškuose, vibracinis aktyvumas matuojamas keliomis skirtingomis koordinačių ašių kryptimis. Darbą sudaro 7 dalys: įvadas, mokslinės literatūros, susijusios su tiriamuoju objektu, apžvalga, tiriamos problemos analizė ir pagrindimas, teorinis pagrindimas, eksperimentiniai tyrimai ir jų rezultatų įvertinimas, lyginamoji analizė, išvados ir pasiūlymai, literatūra. Darbo apimtis – 132 puslapiai teksto be priedų, 139 iliustracijų, 34 lentelės, 37 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / The data of noise level, vibration activity, used electric power, duty research of crank less mechanism are submitted in the final thesis for the master’s degree. For research making was designed and constructed a special test stand, and scheduled research methodology. Experiments were carried out at different speeds of compressors and compressed air system pressure. Noise tests were carried out at several different points of measurement, vibration activity - a number of different coordinate axes. Structure: introduction, review of scientific literature related to the investigating object, analysis and justification of the investigated problem, theoretical justification, experiments and their evaluation of the results, comparative analysis, conclusions and suggestions, references. Thesis consists of: 132 pages text without appendixes, 139 pictures, 34 tables, 37 bibliographical entries. Appendixes included.
6

Comment reply to Does the acceptable noise level (ANL) predict hearing aid use?

Johnson, Earl E. 01 November 2013 (has links)
No description available.
7

Assessment Of Occupational Noise Exposure Of A Plant In Oil Industry

Dal, Ufuk 01 May 2010 (has links) (PDF)
Noise, which is a noteworthy problem in the world of workers, influences the health, safety, productivity and efficiency of those working in heavy industries and especially those working in petroleum industry. The objective of this study is to reassess the protective measures, taken previously by the company, from the point of view of the negative effects of noise on the workers. For this purpose, two approaches are adopted. Firstly, through questionnaires (response rate: 86%) distributed to workers, their subjective rating of, the noise levels to which they are exposed, the factors affecting their working efficiency and, their working conditions are searched. Secondly, noise levels, in the buildings rated as highly and very highly noisy, are measured by sound level meter. Self-exposure of 28 workers is measured by dosimeter. The overall ambient noise level of the 11 buildings and effect of noise on the working efficiency of the workers working in these buildings were respectively found to be moderate and slightly affected. The workplace index was 3 (out of 5). The working conditions index was on the average 4 (out of 5). The Leq values measured in six of the buildings were found to be in the range of 66, 8 &ndash / 100, 0 dBA. 12 out of 28 workers were observed to be exposed to noise levels greater than 80 dBA. The objective (noise measurements) and subjective (questionnaire) results obtained at the end of the afore-mentioned approaches will be of help in the orientation of the workers while estimating their work efficiency and will also serve as a data base for the planning strategy of the interested company.
8

Identifiering och kartläggning av buller i centrala Falun / Identification and mapping of noise pollution in central Falun

Sarhatlić, Nerim January 2014 (has links)
Ett problem i dagens moderna samhälle är att bullernivåerna är för höga. Dessa höga bullernivåer är en hälsorisk och kan ge människan permanenta skador. Buller är något som inte får försummas. Syftet med examensarbetet är att identifiera och kartlägga bullret på Holmgatan i centrala Falun. Syftet är också att analysera resultatet och sätta det i förhållande till myndigheternas krav och riktlinjer avseende bullernivåer. Examensarbetet avgränsas till bullermätning och kartläggning på delar av Holmgatan i centrala Falun, som bedömts vara extra utsatta för buller. Bullermätningarna utfördes under fyra vardagar och under tider från det att de flesta affärer öppnar till att de stänger, kl. 10-18. Metoden bestod utav bullermätningar som utfördes med en timmes intervall längs den utvalda delen av Holmgatan. Dagarna då dessa mätningar utfördes var 2/12 till 5/12-2013. Resultatet redovisas som medelvärdet per timme av alla dagar då bullermätningarna utfördes. Resultatet varierade, det lägsta bullermedelvärdet var 57 dB och det högsta bullermedelvärdet var 83 dB. Det syns tydligt att de högre värdena ligger närmare en gata som används av bussar och andra transportfordon. De lägre värdena låg oftast i närheten av Geislerka parken, som är en stor och öppen yta mitt i Holmgatan. Över lag så låg bullermedelvärdena mellan 60-65 dB. Slutsatsen tyder på att bullernivån på Holmgatan överskrider inte myndigheternas krav på vad som anses som skadligt men ligger strax under riktlinjerna för maximalnivån för utomhusbuller (70 dB). Åtgärder såsom att plantera vegitation på fasader och omleda trafiken skulle kunna vidtas för att minska bullernivån på Holmgatan. / A problem in today's modern society is that the noise levels are too high. These high levels of noise is a health hazard and can give man permanent damage. Noise pollution is something that must not be neglected. The purpose of this study is to identify and map the noise on Holmgatan in central Falun. The purpose is also to analyze the results and put them in relation with the regulatory requirements and guidelines regarding noise levels and to analyze the results and see if actions should be taken against the noise on Holmgatan. The thesis is limited to noise measurements and mapping of parts of Holmgatan, considered to be especially vulnerable to noise. Noise measurements were conducted during four weekdays and during times from when most stores open to most of them then closing, at. 10-18. The method consisted of noise measurements which were performed at hourly intervals along the selected portion of Holmgatan. The days on which these measurements were performed was from 2/12 to 5/12-2013. The results are reported as average value per hour of any day on which noise measurements were made. The results varied, the lowest average noise was 57 dB and the highest average noise was 83 dB. It is clearly seen that the higher values are closer to a street used by buses and other transport vehicles. The lower values were generally near Geislerka parken, which is a large garden, an open area in the middle of Holmgatan. Overall, the average noise values were between 60-65 dB. The conclusion suggests that the noise level at Holmgatan do not exceed regulatory requirements on what is considered as harmful but it is just below the guidelines for the maximum level of outdoor noise (70 dB). Actions such as planting vegetation on the facades and to redirect the traffic could be done to reduce noise levels at Holmgatan.
9

Hlukové emise v chovu kuřat na výkrm / Noise emissions in farming chickens for fattening

STEJSKAL, Jiří January 2016 (has links)
The thesis is focused on the sources of noise in agricultural operations in terms of noise emissions. Agricultural operation in this case was a hall for fattening chickens for meat. The main goal is practical to measure all sources of noise generated during the various operations fattening. The work was primarily necessary to choose suitable habitats for measuring noise sources and measurements of climatic conditions. Followed by calculation of equivalent noise levels and evaluation under applicable legislation. As part of the work was proposed noise protection measures, which would partly help reduce the impact of noise emissions.
10

Caracterização dos ambientes termico, aereo e acustico em sistemas de produção de suinos, nas fases de creche e terminação / Characterization of thermal, aerial and accoustic environment in swine confinement - growing and finishing production

Sampaio, Carlos Augusto de Paiva 16 December 2004 (has links)
Orientador: Irenilza de Alencar Naas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-04T02:45:00Z (GMT). No. of bitstreams: 1 Sampaio_CarlosAugustodePaiva_D.pdf: 1948134 bytes, checksum: b2e69a6cda73b5e8d5079c6d3b0df732 (MD5) Previous issue date: 2004 / Resumo: Emissão e concentração de aerossóis, gases e vapores provenientes do confinamento de animais causam danos à atmosfera, ao ambiente, ao homem e aos animais e às estruturas das instalações. Os contaminantes aéreos possuem efeito negativo sobre a saúde e produtividade dos animais e dos trabalhadores, que expostos a tais substâncias podem desenvolver problemas como irritação do sistema respiratório, pneumonite de hipersensibilidade, bronquite crônica, inflamações das vias aéreas, infecções respiratórias, asma ocupacional, febre e irritação nos olhos, dentre outros. Informações sobre ruídos, gases e poeira e seus efeitos no bem-estar do animal e do trabalhador em sistemas de produção de suínos para as condições brasileiras são escassas, pois estes estudos em sua grande maioria, são relacionados a países de clima temperado, onde as construções são completamente fechadas e o resultado final do ambiente difere das condições brasileiras, além do fator clima e manejo a ser considerado. Este trabalho possui os seguintes objetivos: avaliar o conforto térmico; a concentração de amônia (NH3), sulfeto de hidrogênio (H2S), metano (CH4), monóxido de carbono (CO), oxigênio (O2) e poeira; o ruído e estimar os riscos de exposição ocupacional a estes agentes ambientais. O estudo foi realizado em três granjas de ciclo completo de produção: Granja 1 (creche e terminação, ambos de piso compacto) e Granja 2 (creche de piso semi-ripado e terminação de piso compacto com lâmina d'água), durante o verão e inverno de 2003; Granja 3 (creche de salas com piso semi-ripado e gaiolas), durante o verão de 2002. Nestas instalações, era usada somente a ventilação natural para fins térmicos e higiênicos. Verificou-se que as concentrações médias de H2S e CO ficaram abaixo de 1 ppm e inferiores a 0,1% de CH4 em volume no ar, não ultrapassando os limites recomendados pela CIGR (1994) aos animais e aos limites recomendados pelas NR-15 (1978) e ACGIH (2001) para o trabalhador. A concentração de O2 ficou em média 21%. Com relação ao NH3, foram observadas diferenças (P < 0,05) nas concentrações médias em relação aos horários de alimentação dos animais, às tipologias das instalações e aos períodos avaliados. As análises dos dados revelam a necessidade de se melhorar a qualidade do ar, dando ênfase principalmente aos horários mais quentes e às condições de inverno, já que basicamente o NH3 encontra-se em concentração mais alta em relação à recomendada em diversos estudos. A concentração de poeira foi muito variável, sendo que a concentração de poeira total foi mais alta na creche (0,84 - 9,16 mg.m-3) do que na terminação (0,84 - 3,34 mg.m-3) e a concentração de poeira respirável foi mais alta nas unidades de creche, porém inferior a 3,67 mg.m-3, não apresentando riscos à saúde. As concentrações dessas substâncias (gases e poeira) foram inferiores àquelas verificadas em instalações fechadas. O ruído contínuo e de impacto se manteve nos limites recomendados pelas NR-15 (1978) e ACGIH (2001), podendo-se considerar o ambiente salubre. Entretanto, considerando o ruído de pico observado nos horários de alimentação e vacinação principalmente nas instalações para terminação, recomenda-se o uso de equipamento de proteção auricular. Na Granja 3, notou-se que o ruído contínuo e de pico na sala de creche com gaiolas foi superior ao ruído na sala de piso semi-ripado, o que pode estar relacionado a um maior bem-estar dos animais criados no piso semi-ripado. Verificou-se também a tendência do ruído de se acompanhar as condições de conforto térmico das instalações / Abstract: Emissions and concentrations from livestock buildings must be identified and analyzed with regard potential detrimental or hazardous effects on the atmosphere, man, animals, buildings and environment. Substantial evidence shows that some gases and particulates have a negative effect on health and productivity of animals. Labor in livestock buildings are exposed to a complex mixture of aerial contaminants and some can develop respiratory problems including irritation and inflammation of the respiratory tract, hypersensibility pneumonitits, chronic bronchitis, respiratory infections, occupational asthma and toxin fever and irritation of the eyes. Information about noise, dust and gases concentrations and the effects on animal¿s welfare and the workers in swine systems confinements production are rare in tropical regions. The majorities of the information addresses regions where the livestock buildings are total enclosed and the conditions of climate and manage are different too. This study was carried out during summer and winter of 2002/2003 and the objectives were: to evaluate the noise environment, air quality (NH3, H2S, CH4, CO, O2 and dust concentrations), the environment thermic, and estimate the occupational risk exposition the workers at three commercial swine production facilities: Housing 1 - growing and finishing with full slatted floors, Housing 2 - growing with partially slotted floor (40% of the pen area) and finishing of full slatted floors with thing layer of water in behind to the stalls and Housing 3 - growing with suspend cages and semi-slotted floor rooms of breeding. In the housings was used natural ventilation for thermal and hygiene environment control. The respective concentrations of H2S, CO, O2 and CH4 were less than 1 ppm, less than 1 ppm, 21.0% and less than 0.1% by volume. The concentrations of substances during these measurements are not dangerous of the animals and the workers as according to CIGR (1994), NR-15 (1978) and ACGIH (2001). The average concentration of NH3 presented significant difference (P < 0.05) with regard to feeding schedule, typology and periods available. The analyses of ammonia showed that some schedule mainly during winter are necessary attention especial because these concentrations were higher than most recommended by several studies. Total dust concentrations were the lowest for finishing units (0.84 - 3.34 mg.m-3) and the highest for growing units (0.84 - 9.16 mg.m-3). The respirable dust concentrations were highest than for growing units, and less than 3.67 mg.m-3. These concentrations were less than the limits recommended of the workers. The airborne concentrations of substances measured in the present study were all lower than most of published studies conducted in mainly enclosed swine buildings. The noise level (continuous and impact) were less than recommended by norms (NR-15 and ACGIH), however the peak noise level observed during feed alimentation and other task schedule mainly finishing swine housing recommended ear protection. In Housing 3 observed that noise continuous and peak in the room with suspend cages were highest than semi-slotted floor. These measurements indicated higher welfare the animals in the semi-slotted floor breeding. There was also tendency to increase the noise as thermal comfort environment conditions decreases / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola

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