The report examines the factors which may be a contributing cause to the problems that are present when ferritic stainless steel are eddy current tested in a warm condition. The work is carried out at Fagersta Stainless AB in Fagersta which manufactures stainless steel wire. In the rolling mill there is an eddy current equipment for detection of surface defects on the wire. The ferritic stainless steels cause a noise when testing and this noise complicates the detection of defects.Because of this, a study was made of how the noise related to factors such as steel grade, temperature, size and velocity. By observing the signal and with the possibilities to change the equipment settings the capability to let a signal filter reduce the noise level were evaluated.

Too high levels of noise lead to various health problems and cost society billions of SEK peryear. In this thesis we have examined a model of the A40E articulated hauler at VolvoConstruction Equipment in Braås. We have tried to reduce cabin noise in an articulated hauler,while also providing a way on how to proceed with a machine when the cabin does not measureup to the sound requirement. The best way to find leaks were with a reference source of model4205 and its speaker HP 1001 from Brüel & Kjaer in the cab and then walk around and listen towhere the reference source was more prominent. In this way, we found that the edges and theplugs were sensitive areas.

Inventories of epiphytic lichens on Scots pine (Pinus sylvestris) were conducted at three sites in east central Sweden: along the newly build motorway (Road E4), along the old road (Road 600) and in a reference site, to compare the effects of traffic pollution on lichen diversities. At each site, species richness, lichen mean sensitivity value (MK), air quality index of the forest stand/sample plot (LKI) and nitrogen impact value (N) were calculated and it was tested if there was any difference between the sites. Twenty-four species were observed in total, and Parmeliopsis ambigua and Hypogymnia physodes were the most common species at all sites. At Road E4, fewer lichen species were observed than at the other sites and this might be due to the impact of air pollution. The species richness at Road 600 was similar to that of the reference site, which might be explained by the improved air quality.

Wind power in Sweden is expanding in response to the government's decision that 49% of Sweden's power should originate from renewable energy sources by the year 2020. Problems with noise and sound emissions related to wind turbines are a constant argument against the wind power expansion and this paper means to examine if vertical axis wind turbines might be a viable alternative to the conventional horizontal design for noise sensitive areas. In order to determine factors like difference in frequency, noise propagation and noise emission level, measurements of both horizontal and vertical axis wind turbines have been completed and the data analyzed with MATLAB. It is shown that there is a difference in how the noise from the two types of turbines propagates due to avariation in the frequency spectra of the emitted sound. It is also shown that vertical axis wind turbines generate a lower sound emission with less intensity inthe lower frequencies..

Noise is a growing health problem. People are not always aware of the injuries that noise can cause. The media culture of today has a big influence on teenagers. This is caused by portable music players, computers, concerts etc. The schools are having larg classes and that can cause a lot irrelevant speech during lessons.

Noise in schools can have negative effect on the teaching environment and speech perception. The national Child Environmental Health Surveys (BMHE) conducted in 2003 and 2011 studied how 12-year olds experience their sound environment in school. Results showed that the number of pupils that experience annoyance from noise increased from 2003 to 2011.Aim: The aim of this study was to study how 12-year olds perceive their sound environment in school.Methodology and material: A quantitative questionnaire survey was conducted in the sixth grade at two schools. The questionnaire used included questions from BMHE and self-produced questions. Sixtynine students answered the questionnaire.Results: Over 50 % of the respondents experience annoyance from noise in school several times a week.

Landscape architecture is a visual profession, but other senses also affect our interpretation of a place. Sounds can give us a lot of information about an environment, and they are often perceived as positive. Despite this, research about outdoor sounds most often focus on the reduction of unwanted sounds ? noise ? but the absence of noise does not result in a good soundscape. To accomplish this, sounds we appreciate are needed.

In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch.

Background: Phonemically balanced word lists are used when obtaining speech recognition scores in noise. These lists are designed for adults, but are still used for children. To properly obtain speech recognition scores in noise for children, normative data is needed to show what differences there are to be expected between children of different ages. Purpose: The main purpose is to obtain normative data for children in the ages of 7, 10 and 13 years for speech recognition scores in noise using words and to compare these with each other and with normative data of adults. A further purpose is to examine if there is any practice- or exhaustion effect to be seen when obtaining speech recognition scores in noise for children in the ages of 7, 10 and 13 years.Material: The participants were ten 7-year-olds, ten 10-year-olds and ten 13-year-olds.

The industrialization in Sweden has increased the large number of areas that have been contaminated with various types of pollution. One of those sites are the property Höjen 3:24 in Arboga where ?Arboga Mekaniska Verkstad? once been. The property wants to increase the use of the old former foundry building with the adjacent ?plate-workshop? and believe there are two options for the building: That the building either should be used as a warehouse/concert hall, or rebuilt into a cultural center. An environmental evaluation has shown that the levels of heavy metals are over the Swedish environmental protection agency guidelines of less sensitive land.

The aim with my master thesis is to develop and test the applicability of methods to quantify and map solute advective travel times and pollutant transport at the catchment scale. Such quantification and mapping can increase the understanding of catchment-scale pollutant transport in general and contribute to the identification of the main sources of water pollution and the most efficient measures to reduce such pollution. The study area is the catchment of Oxundaån, about 20 km north of Stockholm. For detailed GIS modeling of water flow and catchment-scale contaminant transport in water, I´ve used new high-resolution elevation maps, land cover maps and soil maps combined with other available relevant data..

Since the spring 2003 the tenant-owner home association the Terrace in Upplands Väsby municipality lies straight under the approach route to Arlanda Airport?s new third landing chute. Noise levels of over 70 dB have been measured in the area, which exceeds National Board of Housing?s, values for traffic noise at a terrace in connection to housing. By using the method of hedonisk pricing the essay tries to find out if there exists a willingness to pay to reduce the noise in the area.

Constantly growing demands from the costumers in the Automotive industry forces the subcontractors to seek alternative ways to compete. One parameter of quality is the components tolerance against NVH(Noise, Vibraion & Harshness) aspects. Kongsbergs Automotive has developed a new gear shifter platform (Shift-by-Wire) that is sold to Alfa Romeo and used in of their car models. However, the company is not pleased with the components sound quality, therefore the main purpose of this thesis is to develope a number of concepts that is supposed to enhance these NVH-aspects.To get an understanding of the problem an analysis of the causes of the emitted sound has been done parallell to a product decomposition, function decomposition and a Ishikawa-diagram. Together with these methods has a litterature study been performed to get familiar with the physics of an impact and especially the emittment of noise.

Ljudnivån på intensivvårdsavdelningen är hög. Övervakningsutrustning och medicinskteknisk apparatur bidrar till bullret med sina larm, patientgruppen på intensivvårdsavdelningen är mycket personalkrävande och den höga personaltätheten bidrar till den höga ljudnivån. Forskning visar att buller påverkar arbetsprestationen och kan medföra att det blir svårare att genomföra en uppgift. Mänskligt tal är mer distraherande än annat buller även vid låga ljudnivåer. Syftet med studien är att beskriva hur sjuksköterskor inom intensivvård upplever att buller påverkar arbetsprestationen.

There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly.This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB).