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332 Uppsatser om Thermal bridge - Sida 9 av 23

Legionella i tappvattensystem. Förekomst och förebyggnade-en redogörelse.

Legionella can be prevented, the question is how. This report is a degree in construction engineering education at Chalmers University in Gothenburg. A comprehensive written publication for Legionella-safe plumbing installations is not available and therefore requested. The purpose of this report is to present preventative measures against Legionella bacteria growth in tap water and in other systems where Legionella bacteria are a potential problem. Technical solutions are presented including how different systems function and what their advantages and disadvantages are.

Hur påverkar gummigolv i grisningsboxen suggans liggtider, liggbeteende och hennes tid för att lägga sig?

In the farrowing pens the amount of bedding material and the quality of the concrete floor has a huge impact on both the sow and the piglets. In this study imbedding of rubber flooring on the solid area in the farrowing pen was used to see if it had any effects on the sows lying behaviour when compared to concrete. Another important aspect was to evaluate if the rubber floorings had a high enough durability to resist the normal wear in a farrowing pen. Concrete flooring is assumed to have a higher thermally conductive effect then rubber which can affect the sow?s chance to cool down.

A Cross-Country Skiwear Collection for Beautiful Women

This thesis deals with cross-country ski clothing for non-competitive women. Women in this category look for different clothing features in comfort and aesthetics than male top athletes, for whom cross-country skiwear today often seems to be designed. In this thesis the demands of these women have been mapped out by an interview with a reference group of users. The ergonomics of exercising in the winter outdoors are naturally a base for the collection. The collection consists of three functional layers of garments.

Lagring av kyla i bergrum : Undersökning av ett nedlagt oljebergrum

This thesis considers the use of an oldrock cavern as thermal energy storage.With a large system of differentchillers a model was created to find anappropriate future system. There aremainly two trajectories to take. Eitheran installation of chillers needs to bemade or the rock cavern can be used tomeet the future demand of districtcooling in Solna, Sweden. Additionallythis thesis investigates the possibleuse of different techniques to utilizethe phase change energy of water.Simulation shows that it?s possible toutilize the phase-change energy of afluid; however it?s not economicallyfeasible due to the thermodynamiceffects on the Carnot cycle.

Förstudie för kvalitetssäkringav glidande förband vid Hissmoforsvattenkraftsstation : -Specifikt för aggregat G6 och G7

Jämtkraft AB which is a power production company in Sweden has bought two newhydro power units to their station in Hissmofors. The two new generators are using aconcept with sliding stator feet to handle the thermal expansion.The concept with sliding stator feet on hydro electric generators has not beenworking satisfactory on many hydro power stations in Sweden and has caused a lot ofcosts due to long downtimes.The new station in Hissmofors is very important for Jämtkraft AB, and therefore theywant to know how to make sure that the sliding stator feet are working as theyshould. According to theories and a simplified model of the generator the stator feetdisplacement should be around 1 -1,6 mm.The generators are delivered with a surveillance system that will measure thedisplacement of the sliding stator feet. The signal from the system isn?t accessible forJämtkraft AB but it will alarm when the sliding stator feet are malfunctioning.To secure the function of the sliding feet a logger for the surveillance system or adifferent measurement system must be used; if both systems are used Jämtkraft cansecure the function of the surveillance system..

Miljöcertifiering av ett byggnadsminne

Samtidigt som debatten kring jordens klimatförändring är i full gång har intresset för att miljöcertifiera byggnader vuxit oerhört. För fastighetsägare är det en möjlighet att bevisa för sina hyresgäster och köpare att byggnaden är hållbar. Är en byggnad miljöcertifierad har en oberoende part intygat att den uppfyller en nivå av hållbarhet som bestäms utifrån standardiserade kriterier. Fastighetsägaren kan alltså använda certifikatet i marknadsföringssyfte.Den här studien undersökte om en byggnad som är byggnadsminnesförklarad kan miljöcertifieras med Miljöbyggnad. Målet var att hitta kostnadseffektiva lösningar för att uppfylla de miljöcertifieringskriterier som eventuellt inte uppfylls idag.

Småhusutformning och solenergiutnyttjande

This paper goes through solar energy and what uses it has. It is also a guide in the choice of solar collectors forthe real estate that I have drawn for the thesis work.Solar energy is a renewable source of energy from the Sun's light. Energy can be used to produce both heat andelectricity through solar collectors and solar cells. Some of the benefits of solar energy is that it is completely freeto extract, environmentally friendly and virtually maintenance-free. Disadvantages are that the technology isexpensive, does not cover the entire energy needs and takes a long time until it pays.

Konstruktion av PID-reglerad motorstyrning

Denna högskoleavhandling beskriver konstruktionen av ett system vars funktion är att PID-reglera ett linjärställdon kopplad till venturi. Syftet har varit att få fram en reglering på venturin så att förutsättningarna förblir desamma vid mätning av olika temperaturer och lufttryck i en testrigg. Denna testrigg används för att utveckla produkten Varivent som används för att uppfylla högre miljökrav på förbränningsmotorer.I arbetet beskriver jag de olika krav som funnits för att bygga det nya systemet, dessa var ingångar, utgångar, mikroprocessor, reglering,kommunikation samt övriga krav. Jag diskuterar de svårigheter och möjligheter som är förknippade med kraven och tar även upp de komponenter jag använt samt deras egenskaper. Det svåraste momentet har varit PID-regulatorn som både varit en viktig och en svårlöslig del i konstruktionen av systemet.

Validering av glidande statorfötter på Hissmofors G6 och G7

Jämtkraft AB has recently modernized its hydropower station at Hissmofors by replacing four older worn out units with two new units. The generators uses a concept with sliding stator feet to deal with the thermal movements that occur in the stator during operation when the unit is operating intermittently. At other sites, this method revealed shortcomings in the reliability. This has made Jämtkraft AB feel uncertainty about its function and therefore want to investigate it during an early stage. The generators have a built-in monitoring system for the sliding stator feet and by using data from there the function of the sliding stator feet has been investigated. The study focused on how the different stator feet move relative to each other and how the eccentricity and deviation from roundness changed during operation. The results show that there are several indications that the function of the sliding stator feet is not satisfactory.

Alarm på bryggan : trygghet och irritation

Arbetet på fartygsbryggor består till en stor del av kontrolluppgifter. Operatörerna, bryggteamet, har därför kontroll-  och alarmsystem till förfogande. Samspelet mellan människa och system beror delvis på användarens kunskaper och erfarenheter och delvis på bryggdesign och teknikens användarvänlighet. Arbetets ämne är hanteringen av alarm och alarmsystem på fartygsbryggor.  Syftet  var att  undersöka om det finns strategier för detta och i så fall att belysa hur dessa strategier ser ut. Därför undersöktes sju styrmäns erfarenheter med kvalitativa metoder, med halvstrukturerade intervjuer och med innehållsanalys.

Mätsystem för effektförluster i en högfrekvenstransformator

To measure losses in a transformer with today?s methods is either slow or insecure. There s a new method developed by Alstom that hasn't been actualize in to a test-system and that has been the assignment in this project. The idea is built on a switched system and a CLR- circuit in the resonant frequency. The test-system has a calculated power-loss that make the efficiency to be as high as 99,8% and in reality over 95%.

Påverkan av skogsbrand på litiska arkeologiska fynd ? experimentell simulering av brand

This is a paper about the effects from smoldering fire on lithic objects from an archaeological view. The introduction gives the background to this paper, a short orientation to forest wildfires and why the work is limited to: flint, quartz, quartzite and slate. Material and methods describes the stone materials and the setup that was used in the temperature logged tests with three replications for each type of material. The fuel in the burnings was peat on a bottom of sand. Flint showed a more drastic effect from heat compared with the other materials. Slate seems to have greater tendencies to change to darker colour and luster at lower temperatures than the other materials.

Gotland ponies on extensive pastures ? a welfare assessment

Swedish farmers have the possibility to be subsidized by EU rural development programme for grazing animals on pastures to promote the biodiversity of flora and fauna. The environmental remedy sometimes does not allow supplementary feed and at the same time the Swedish Animal Welfare Act and the Swedish Agricultural Board?s regulations for animal welfare and protection states that animals, in this case horses, shall be fed with food of good quality and adapted for the species. The regulations also state that they should have an individual feeding regime that enables them to maintain a normal body condition. The aim with this master thesis has been to investigate if it is possible to keep Gotland ponies on extensive pastures, during late spring and summer and still maintain animal welfare. The horses were assessed every fourth week using a welfare assessment protocol developed in line with the Welfare Quality® project (submitted, Viksten et al) where physical, behavioural and resourcebased parameters were observed. Twelve one-year old stallions of the breed Gotland ponies purchased from different breeders were used in the study.

Energiåtervinning från gjuteriprocess till fastighet, undersökning för ökat utnyttjande av spillvärme

This diploma work on D-level is made in cooperation with Varnäsföretagen AB in Eskilstuna. The company performs contract manufactured aluminium goods. This work is a continuation on earlier diploma work in Varnäsföretagen AB. Even if the industry process consumes much energy for melting the aluminium goods, they consume a great amount of oil to warm up the building. The purpose of this work is to examine some places in the building and the process to see how much energy it is possible to recycles to the heating system and reduce the costs for heating.

AIS i havets och tankens strömmar : En etnografisk studie av nautikers användning av transpondersystemet AIS

An ethnographic study loosely informed by the theoretical framework of distributed cognition was carried out in order to describe how mariners have adopted the Automatic Identification System (AIS) in their work practice, or"made the technology their own". AIS is a transponder-based identification and communication system that allows ships to automatically identify and track each other. In addition to facilitating the identification and tracking of ships, objectives behind the introduction of AIS are to"simplify informational exchange", and"provide additional information to assist situation awareness". Participant observation and interviews were made at four different ships, as well as at two shore stations. A focus group was also held at a maritime conference.

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