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852 Uppsatser om Noise reduction - Sida 46 av 57
Framtagning av beräkningsprogram för helsvetsade balk-balkinfästningar i stål : Verifiering genom fullskalig belastningsprovning
AbstractPurpose ? The purpose of this study is to investigate possible reasons for long lead-time in a customer driven production, and how the lead-time can be reduced. To fulfil the purpose the study has been broken down into two questions.1. Whichfactorsaffectthelead-timeinacustomer-drivenproduction?2.
Optimering av biologisk fosfor och kvävereduktion i ett reningsverk för hushållsspillvatten
In connection with Henriksdals wastewater treatment plant (WWTP) a smaller plant is situated called Sjöstadsverket where new methods for wastewater treatment are tested and evaluated in different process lines. On one of the lines experiments with enhanced biological phosphorous removal (EBPR), have been carried out to evaluate if it is a good alternative to traditional chemical phosphorus removal. This thesis evaluates the results from the experiments conducted during fall 2005.The incoming water from Hammarby Sjöstad consists of only household wastewater, which gives a wastewater with high concentrations of nutrients and organic carbon. This is partly positive, because one of the limiting factors for effective biological phosphorus removal is the lack of easily biodegradable organic carbon. The high concentrations of ammonium and phosphorus demand a high reduction to achieve the requirements of outgoing concentration.To optimize the process experiments with different recirculations and different aeration techniques have been made.
Frysa livsmedelsrester eller kassera dem för biogasproduktion : En studie, ur livscykelperspektiv, av energianvändning och växthusgasutsläpp
Food is widely consumed and in 2011 an average American devoured approximately one ton of food. The production of these goods requires large amounts of energy and contributes to 22-31 % of all greenhouse gas emissions occurring in Europe. More than one third of the produced food is discarded instead of consumed, and food waste make up about 30 % of the waste generated by households. 60 % of this food waste could be avoided if the eatables were handled in a better way.Avoidable food waste arises partly because residues from food are not taken care of, and because the food is not stored in a way that optimise its durability. Residues arises part- ly because of the contradictory and complex demands of everyday life and are, because of our busy lifestyle, difficult to avoid.
Hållbara uppvärmningsalternativ för hotellstugorna på Grinda : En kvantitativ studie gällande hållbara uppvärmningsalternativ på en skärgårdsö
Skärgårdsstiftelsen, which is responsible for several of the archipelago islands in Stockholm, has chosen to explore the possibilities for more sustainable heating systems in buildings on the islands in collaboration with KTH. A reduction of energy use and improving the efficiency of existing heating systems are included as part of the environmental work. This report studies the island of Grinda, which is located outside the area of Vaxholm in Stockholm. The study area consists of a guesthouse consisting of a restaurant as well as conference facilities and four neighboring cottages used for overnighting. The cottages now run solely on direct electricity, both for heating and hot water.
MOLNU : Att utveckla ett gemensamt gränssnitt
Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.
Om rökgasåterföringens påverkan på NOx-utsläpp och verkningsgrad
Föreliggande rapport är ett resultat av ett examensarbete utfört på Lulekraft AB (LUKAB), med syftet att dimensionera en återföring av rökgas. Målen är att sänka utsläppen av NOx, att minska fluktuationerna av temperaturen i överhettarna vid bränslebyte samt att undersöka ifall verkningsgraden ökar med implementerad rökgasåterföring.Ett flertal olika sätt att reducera utsläppen av NOx finns grundligt beskrivna i litteraturen, såväl i rökgasflödet som av modifikation av brännarna. Åtgärder i rökgasflödet är t.ex. rökgasåterföring (FGR, flue gas recirculation) och selektiv katalytisk reduktion (SCR, selecive catalytic reduction). Rökgasåterföringen sänker temperaturen på flamman, vilket leder till en sänkning av bildningen av termisk NOx.
Unga invandrares uppfattning av fenomenet hälsa och ohälsa : En tolkning av livserfarenheter ur ett fenomenografiskt perspektiv
Västerländsk mindfulnessmeditation har sina rötter i tusenårig buddhistisk tradition, främst genom vipassana- och zentraditionerna. Senaste tiden har mindfulness ökat i popularitet och blivit en accepterad klinisk metod i former som mindfulness based stress reduction. Möjligheten att undersöka dess effekter genom neurovetenskapliga metoder bidrar med intressant och viktig forskning om mänskligt välbefinnande. Dock har tidigare studier visat på bristande samstämmighet vad gäller resultat och metod. Uppsatsen är en litteraturstudie där det huvudsakliga syftet är att utifrån nyare studier undersöka de tydligaste effekterna på hjärnfunktion och struktur av långvarigt praktiserande av mindfulness utifrån vipassana- och zenmeditation.
Undersökning av deponerat ferrokromstoft : Utvärdering av ny behandlingsmetod
The production of ferrochromium alloys at Vargön Alloys AB contributes to formation of unwanted ferrochromium dust, which contains toxic Cr(VI). The dust is since summer 2005 treated with an iron-sulphate solution to reduce Cr(VI) to the non-toxic Cr(III). A year later the treatment technique was improved and disposal occurs in cells on the landfill. The cells can be up to 300 m3 and the edges can be made out of fro example concrete. Tests are conducted on the treated dust when it is disposed.
Planering med avseende på trafikbuller i Göteborg
I takt med att besökare och patienter ökar måste kontinuerligt Östra sjukhuset verksamhet utvecklas. Detta medför omläggningar i trafiken och förflyttningar av verksamheter. Idag finns flertalet brister kring Östra sjukhusets fysiska planering som behöver ses över, dessa är bland annat trafikflöden, säkerhetsaspekter och parkeringsmöjligheter.Rapporten redogör för förändringar i den fysiska planeringen som förbättrar dess utformning. Genom studier av relevant litteratur och diskussioner med expertis har förslag av problemområden tagits fram. Dessa har sedan bedömts efter listor av deras respektive för- och nackdelar som kunnat urskiljas.Arbetet visar framtagandet av ett väl fungerande förslag som kan verka som en bas för idéer till nutida och framtida förändringar kring den fysiska planeringen.
LCA av dricksvattendesinfektion : en jämförelse av klor och UV-ljus
Disinfection methods for drinking-water produced at the two water works of Stockholm Water Co are compared in this study. Three different nethods are compared; disinfection with chlorine gas, disinfection with sodium hypochlorite and disinfection with UV-light and monochloramine. The method used is Life cycle assessment, LCA. LCA is defined as the compilation and evaluation of the inputs, outputs and potential environmental impact of a product system shroughout its life cycle. The environmental burden is compared for the three different disinfection methods.
Metoder för lastprioritering i fjärrvärmecentraler
A problem in the field of district heating is the oil burners needed to provide power when a peak load occurs. One possible way of reducing the needed amount of oil is to reduce the power demand for space heating in the district-heating substations when the need for district heating water exceeds a certain limit. This can be done by use of a locally working controller function.In this Thesis the options concerning load priority are evaluated. To evaluate the potential for using controller functions concerning peak load priority an experiment was brought out in a chosen district-heating substation. The impact on the indoor thermal comfort during a heat reduction was also taken into account.
Säkring av samtliga kritiska skruvförband i mellanstora asynkronmotorer
The purpose with this thesis is to get a compilation of all the critical bolted joints of all enginesproduced at LV Motors. ABB LV Motors produces induction engines with seven shaft heights. Eachengine size exists several variants of components ex. standard shield and flange shield. Depending onwhich components the engine is equipped with arises various types of strains in the engine's parts,certain assembly ways are more favourable than other.The most critical parts in the engine from a mechanical point of view are the screw units betweenshield/stator, feet/stator and bearing cover/shield.
Kustnära ekosystem som skydd mot naturkatastrofer : en litteraturstudie från ett riskhanteringsperspektiv
Research suggests that society's vulnerability to natural disasters along coasts could increase as a result of climate change, which is likely to lead to elevated sea levels and possibly an increase in the occurance of meteorological phenomena such as storms and tropical cyclones. Following the Indian Ocean tsunami disaster in 2004 and Hurricane Katrina in 2005, both of which received considerable media attention, empirical data has indicated that coastal vegetation might be able to protect and reduce damages to coastal communities during tsunami events and tropical cyclones.The aim of the essay has been to study the function of coastal ecosystems as protection against tsunami waves and storms from a risk management perspective, meaning that I have, through an overview of scientific articles, compiled current research on how coastal ecosystems can attenuate storm surges and tsunami waves, and analysed how this knowledge can be put into practice in coastal communities from a risk management perspective, i.e. if coastal ecosystems are a viable risk reduction measure, are practically applicable, and if so, how they could be applied.There is empirical evidence suggesting that coastal ecosystems, particularly mangroves, can reduce the strength of a tsunami wave, but full scientific consensus on this issue has not yet been reached. With regard to protection against storm surges, there is extensive scientific evidence that coastal vegetation can mitigate damages and reduce the height of a storm surge, although the wave has to traverse several kilometres inland through thick vegetation for the protection to be effective. A synthesis in the form of a figure regarding the many physical factors that influence wave development through coastal ecosystems has been created in an attempt to simplify and explain the phenomenon.The conservation and restoration of coastal ecosystems can be justified from a risk management perspective, but planting new forest belts for the purpose of disaster mitigation is quite unrealistic and can rarely be sustainable, since, for protection to be effective, the forest belt must extend several kilometres inland from the coast, and would thus likely prove difficult to implement along coastal societies..
Medvind eller motvind? : granskning av fem tillståndsansökningar från vindkraftprojektering i Sverige
The Swedish Government has decided that Wind power should have a higher contribution to the electricity generation in Sweden. Their goal is that, by 2015, the yearly production by Wind power should generate 10 TWh. In year of 2006, the 760 wind mills in Sweden generated only 0,936 TWh. Despite good wind conditions in a large extend of Sweden's land- and coast areas, the slow rate of new wind mills establishments will likely result in unattainable goals.
The major problem for new establishments of wind mills is the extensive and complicated permission process. An expert group of environmental studies (Expertgruppen för miljöstudier) was commissioned by the Government to make a report concerning the problems with the expansion of wind power in Sweden.
Skiftarbete i byggindustrin och dess värde för aktieägarna
The foremost objective of business organizations is to generate value for shareholders and to opt for strategies which optimize it. Hence it is of key concern for business leaders to appreciate how operations best are run to maximize value creation. This study explores how financial theory can reveal the link between one particular business strategy and the corresponding effect on shareholder wealth. The question in focus is whether construction companies can enhance their value creation by implementing shift-work to increase the weekly production rate. The thesis particularly targets apartment block projects in Sweden and has the construction company Peab AB as primary object of study.