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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

Prediction and control of road traffic noise associated with non-free flowing vehicular traffic

Jraiw, Kadhim Salih January 1987 (has links)
No description available.
2

Noise Levels in the New Zealand Health Industry

Crowther, Carol Faye January 2013 (has links)
The aim of this study was to investigate noise levels in the New Zealand health industry. The goal was to investigate the room acoustics and the characteristics of the noise sources along with noise exposure of health care workers, in New Zealand, in dental clinics and orthopaedic cast clinics and assess whether they are at risk of noise-induced hearing loss (NIHL). A literature review was conducted to determine the definition, cause, and ways to prevent NIHL in relation to the dental clinics and orthopaedic cast clinics. Also determined from a review of the literature were ways to assess and monitor the acoustics of these spaces. Initially room acoustic measurements of background noise levels as well as reverberation times were made and frequency information on the major noise sources was obtained. This was followed by measurement of the daily noise dose exposure of staff working in the participating dental clinics and orthopaedic cast clinics. It was found that noise dose levels did not exceed the damage risk criterion set by The New Zealand Occupational Safety and Health Service of Leq8h of 85 dBA and therefore staff were considered to not be at risk of NIHL. However, the background noise levels measured may be putting healthcare workers at risk of non-auditory related effects of noise exposure, affecting work performance, cognitive abilities and vital communication between staff and patients. Healthcare workers may also be at risk of non-auditory health effects due to increased noise annoyance leading to raised stress levels, which may ultimately lead to pathophysiological changes in the myocardium. Future research in the area of noise levels in the New Zealand health industry should be performed to obtain noise data on a larger sample and look further at the non-auditory health effects of exposure to noise in the health industry.
3

Comparative evaluation of the AES-Chemunex lab blender Smasher®, Seward Stomacher®, Interscience Bagmixer® and Pulsifier® on viable cell counts of foods, noise level, ergonomics, and ease of cleaning

Caballero Vidal, Cesar Guillermo January 1900 (has links)
Master of Science / Food Science Institute - Animal Science & Industry / Daniel Y.C. Fung / Proper microbiological examination of foods involves proper sample preparation in terms of mixing the solid or liquid food with a suitable sterile diluent (usually a 1:10 dilution) in a sterile bag and homogenizing them manually or by means of an instrument. This thesis addresses the effectiveness of Stomacher®, Pulsifier®, Bagmixer®, and Smasher® instruments in terms of: 1) Number of viable cell counts/g of ten food types, 2) Noise level of the four instruments ascertained by a) human and b) decibel meter at five feet (1.52 meters) from each instrument, 3) Ease in cleaning the instruments after use, and 4) Ergonomics. Following the ISO Method (7218:2007), 25 g each of alfalfa sprouts, spinach, peanuts, ground beef, fish meat, hot dogs, tofu, milk, chicken wing meat, and chicken drum stick meat were placed individually in a sterile sample bag containing 224.5 mL of 0.1% Peptone water plus 0.5 mL of E. coli inoculum diluent. Each food was homogenized for 60 seconds in each of the instruments. During each treatment four laboratory workers standing at five feet (1.52 meters) from the instrument assessed the noise level as: very quiet, quiet, nearly quiet, acceptable noise, and loud. Also the noise level was monitored instrumentally by the use of a decibel meter and recorded as Db. Ease of cleaning and ergonomics were determined with the aid of a subjective scale set with the Stomacher® as a reference point. The results indicate that all four instruments have similar performance in regards to viable cell counts. However, in regards to noise level, the Smasher® and the Bagmixer® are the quietest compared to the Stomacher® and then the Pulsifier®. The Smasher® is also the instrument with the highest ranking in ease of cleaning and ergonomics.
4

Impact of stiffness and damping capacity using two different rubbers on friction coefficient and noise levels of brake materials

Punna, Harshitha 01 May 2020 (has links)
Friction contact with both external and internal environments can significantly influence its efficiency, which could cause friction instabilities, vibration, and noise. Focusing on the effects that troubles brake pad, rotor, and friction-induced NVH, the main motivation for this study is to understand its drawbacks for some extent in a braking system. By proper study on applied statistics, an experimental design is planned. The design has friction tests that are performed by scaling down real test properties used in dynamometer to scaled-down properties in a subscale tester by using scaling law of physics. The test has two different types of rubbers with different humidity conditions with respect to two different brake pads in a small-scale tester, the Universal Mechanical Tester (UMT). This friction experiment helps in determining how different rubbers impact its stiffness on the coefficient of friction and noise levels, also to evaluate which scenario has the better damping capacity. The effect on the coefficient of friction and noise levels with and without rubbers is also compared. The results are subjected to the Design of Experiments analyses test know the statistical relationship between factors affecting the process and output of that process at different controllable variables namely humidity and temperature.
5

The Effect of Two Levels of Noise, Two Types of Noise, and Anxiety on Student Performance of a Coding Task

Nearing, William E. 08 1900 (has links)
This study dealt with the effect of low-level noise and high-level noise, of white noise and varied noise, and of high manifest anxiety and low manifest anxiety on college students' performance on a coding task. The conclusions of the study, based upon the hypotheses, were as follows: 1. Level of anxiety does not affect performance on a coding task. 2. The level of white and level of varied noise does not affect performance on a coding task. 3. Varied noise has a positive effect on performance on a coding task.
6

Bullrets omfattning och inverkan på sjukhusmiljö

Bååth, Mattias, Collins, Skúli January 2005 (has links)
Syftet med litteraturstudien var att undersöka hur buller påverkar sjukhusmiljön med hänseende på vårdpersonal och patienter. Studiens avsikt omfattar även en undersökning av vårdpersonalens och patienters eventuella olika uppfattningar angående buller. Effekterna av buller och dess omfattning inom vårdavdelningsmiljön har också undersökts. Resultatet av studien visar på att bullermiljön på sjukhus överskrider de riktlinjer för buller som WHO fastslagit. Vidare visar studien på indikationer på att brittiska sjuksköterskors kunskap angående fenomenet buller är bristfällig. Sjuksköterskors och patienters uppfattningar av buller varierar till viss del. / The aim of this study was to examine how noise effects the hospital environment with regards to nursing staff and patients. The aim also includes nursing staff’s and patients’ possible different perceptions’ of noise. The extent and effect of noise on the ward have also been studied. The result of the study shows that the noise environment of the hospital. exceeds the recommended guidelines set by the WHO. Furthermore the study indicates that nurses in the UK have poor knowledge about the noise phenomenon. Nurses ‘and patients’ perceptions’ regarding noise differ to some degree.
7

Tranquility in the city

Watts, Gregory R., Pheasant, Robert J. January 2013 (has links)
no / The number of people visiting their local parks and countryside is increasing according to a recent survey published by Natural England [1]. An important reason given for visiting green spaces was to “relax and unwind” and these areas can be considered restorative or tranquil environments giving relief from cognitive overload and reduction of stress. Our green spaces can be a refuge from the din of city life and the green environment can provide shelter for wildlife and bird song can be heard. But are they suffi- ciently tranquil and what guidance do we have for improving such spaces if they are not?
8

Samband mellan ljud i öppna kontorslandskap och behovet av återhämtning efter arbetstid : - En kvantitativ studie

Danielsson, Thérèse January 2020 (has links)
Bakgrund: Tidigare forskning indikerar att höga ljud i öppna kontorslandskap har negativ inverkan på kontorsanställdas prestation och välmående på arbetet. Trots att flertalet studier har gjorts kring olika kontorsmiljöer finns inte mycket forskning om hur ljud i öppna kontorslandskap påverkar behovet av återhämtning efter arbetstid. Syfte: Syftet med studien var att undersöka i vilken utsträckning upplevelsen av höga ljudnivåer och störande ljud på arbetsplatsen har samband med behovet av återhämtning efter arbetstid, bland anställda som arbetar i öppna kontorslandskap. Metod: Metoden bestod av en kvantitativ enkätstudie av tvärsnittsdesign. Behovet av återhämtning mättes utifrån en kortversion av Need for Recovery (NFR) Scale. Ljudnivåer och ljudstörningar mättes utifrån formuläret Ljudstörningar och höga ljudnivåer i arbetsmiljön. Enkäten skickades ut till kontorsanställda på 16 olika arbetsplatser runtom i Sverige, varav sammanlagt 61 respondenter medverkade i studien. Resultat: En hierarkisk multipel regressionsanalys visade ett positivt samband mellan höga ljudnivåer, ljudstörningar och återhämtningsbehov. Ett signifikant samband (p < .05) kunde konstateras mellan ljudstörningar och återhämtning som var oberoende av ljudnivåer. Däremot påvisades inget signifikant samband mellan ljudnivåer och återhämtningsbehov oberoende av ljudstörningar. Slutsats: Resultatet indikerar att störande ljud i öppna kontorslandskap har betydande påverkan på behovet av återhämtning efter arbetstid. Även om inget signifikant samband mellan prediktorvariablerna och utfallsvariabeln kunde påvisas kan ljudnivåer ändå vara betydande för upplevelsen av störande ljud och behovet av återhämtning. För att kunna dra kausala slutsatser är fortsatt forskning genom prospektiva studier nödvändigt. / Background: Research indicates that open plan offices are accompanied by high noise levels which have a negative impact on performance and wellbeing at work. However, little is known about how noise levels and noise annoyance associate with need for recovery (NFR) among employees in open-plan offices. Objective: The purpose of this study was to investigate whether there is an association between experiences of high noise levels, noise annoyance and need for recovery among open-plan office workers. Method: The study was performed with a cross-sectional design. Need for recovery was measured with a short version Need for Recovery (NFR) Scale and noise levels and noise annoyance was measured with Noise Annoyance and High Noise Levels in Work Environments. The questionnaire was sent out to 16 workplaces in Sweden and contained responses from 61 employees. Results and conclusions: Hierarchical multiple regression analysis showed a positive association between experienced high noise levels, noise annoyance and NFR. A significant (p < .05) association was found between noise annoyance and NFR, independent of noise levels. However, no significant association was found between noise levels and NFR when both predictors were included in the same model. Results suggest that noise annoyance, compared to noise levels, has a more important impact on NFR. Even if no significant association were found between both predictors and the outcome variable, noise levels might influence the experience of noise annoyance, and therefore also be important for NFR. However prospective studies are needed for causal inferences.
9

Mount Hope Noise Survey: Present Levels And Predicted Increases with Expansion

Gidamy, M. Hazem 04 1900 (has links)
<p> This study deals with applied research in the field of environmentai noise problems, specifically the measuring of noise patterns near Mount Hope Airport originating from subsonic jet aircraft using the present runway facilities. Based on actual measurements the results have been analyzed and reduced to simple contour lines. </p> <p> An attempt has been made in this study to relate the concept of community noise in the vicinity of the airport to specific runway configurations, traffic density and patterns, and to provide a comparison between the noise levels due to the existing operations and those which may result due to the proposed expansion. Versatile computer programs have been developed in this study to simulate an airport model, compute and construct the noise contours for any combination of design requirements such as runway orientation, flight procedure, type of aircraft, etc </p> / Thesis / Master of Engineering (MEngr)
10

Buller från byggarbetsplatser : En undersökning om eventuella bullerproblem för befintliga bostäder i Öster Mälarstrand i Västerås

Mohamed, Abdulahi, Ntamulenga, Bahati January 2021 (has links)
Problem background: This thesis in building technology at Mälardalen University examines the noise level of the constructions on Öster Mälarstrand. The area Öster Mälarstrand is in the eastern part of Västerås next to the water area Mälaren. This district began to build in the end of the 20th century, and the area went from an industrial field to become as described, one of the best places in Västerås to live at. The district is now an area with a large extent of residentials and other necessities such as banking, gym, cafes, restaurants, shops and a large marina. Öster Mälarstrand is still under constant construction of new buildings. The purpose of the survey is to investigate the noise level on Öster Mälarstrand, and if the construction sites are customised to the guidelines that exist regarding noise and noise levels outside in a residential area. The work is summarized and ends by giving examples of measures to reduce noise and noise levels in the area. The method is based on own noise measurements, calculations and interviews. The noise measurements carried out at three specific locations on Öster Mälarstrand during four working days when constructions were underway. Interviews have also been conducted with 50 people who live in the area. The calculations of the noise measurments showed several varying values, but one thing that is clear is that the noise calculations that was executed, exceeds the guideline values set for noise-levels in Öster Mälarstrand. The interviews that were conducted presents that a majority of the interviewees thought that the noise level of the constructions on Öster Mälarstrand was disturbing, especially now during the pandemic of Covid-19, when several people started working from home. The conclusion in this thesis is that noise levels exceeds the guideline values ​​that exist according to the Swedish Environmental Protection Agency. The interviews in the area show that the majority of the participants experience the noise from the construction site as a disturbance.

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