Sökresultat:
785 Uppsatser om Ground faults - Sida 44 av 53
Selektivitet mellan hög- och lågspänningssäkringar ? I anläggningar med transformatorer ? 500 kVA
Göteborg Energi AB är ett bolag med höga ambitioner att säkerställa ett stabilt distributionsnät för sina kunder. Med ett säkerställande följer åtgärder i form av beräkningar för komponenter som transformatorer av olika märkeffekt, hög- och lågspänningssäkringar och andra kritiska skyddsanordningar som t.ex. reläskydd. Vid ett flertal tillfällen under de senaste åren har det uppmärksammats en problematik där ett fel i lågspänningsnätet har löst ut anslutande transformator. Felet har grundat sig en svag selektivitet mellan transformatorsäkring och lågspänningssäkring.
Delta X : Utveckling av värmeväxlare
Stockholms vattenskärning AB in Kungsängen has through the acquisition of a company begun to design and produce aircraft heaters whose origin is early 1970s which follows a high inefficiency in terms of energy consumption and size.The aircraft heater, which is sold worldwide, serves its purpose for customer satisfaction and has done so ever since it was developed in the 70s.Stockholms vattenskärning AB is now investigating the possibility in making the aircraft heaters more efficient, both in terms of energy consumption but also on a more efficient design with the belief that it would lead them to an edge in the market. The aircraft heater consists of several main components whose function altogether is to keep passenger aircrafts warm while they are on the ground.This project has been limited to the further development of the heat exchanger package which accounts for the conversion of the hot medium to the fresh air being carried in to the aircraft cabin. Work has been divided into different phases in order to create a better understanding of the project range and to make it easier to divide the various elements in the time available, 10 weeks. These phases are literature review, situation analysis, concept generation, CAD, concept comparison and writing reports.After the initial literature review was made, a fundamental theory was written which is essential in understanding the remaining parts of the project.With the theoretical part as support, measurements and calculations were made on the current heat exchange package in a situation analysis to ensure its operation and efficiency.In the concept generation phase, the collected facts from the literature review was used as the basis for creating a matrix. The purpose of the matrix was to indicate the two most suitable types of heat exchangers to develop four new concepts out of.In the CAD phase the four concepts was drawn up and then described with text and images.The last phase is the concept comparison where a concept selection matrix is used to function as a decision basis for further production at Stockholms vattenskärning AB. The four concepts have been developed based on the current heat exchanger and is gradually changed into a design of a cross-flow heat exchanger constructed out of stainless sections. The purpose of this is to have gradual upgrading of the heat exchanger as an option, in order not to saturate the market..
"Varför blev det så här?" : om utemiljön på Herrgården från 60-talet och framåt
The residential yard at Kvarteret Landsfiskalen 1, in the area Herrgården in Rosengård, Malmö was built in 1971 and has since then been reconstructed twice, in 1984 and 2008. The yard is found in an area which was built during the years 1965 ? 1974, a period in which the swedish goverment approved a decision to build one million homes, and much of the events in this particular yard is also typical for the process in many other areas built during the same period.At the original construction the design of the yard was entirely incused by the pressure in time and finance, one was under at that time, in order to over- come the housing shortage. The design it has nevertheless been given, reflects the esthetic ideals of that time well.The building of the area was barely finished when the swedish authori- ties started handing out grants in order to support the rearmament of the outdoor environment in the areas built during the so called ?million program?.
Jordbearbetningsstrategier på hösten inför vårsådd på tyngre lerjordar :
It is important for today?s farmers to minimize the costs for crop establishment, because
of decreased prices and support from the EU. Farmers, who plow in autumn on heavy
clay soil, often do some kind of tillage in autumn to get better soil structure before
spring seeding. This is especially important when growing small seed crop, e.g. sugar
beet and oil plants.
Grafisk skärpa : ett arbete om gaturummet
The streetscape is a complex environment with a lot of different parts and users.
If you look at the streetscapes main parts you have floor, walls, roof and
furniture. The floor in the streetscape, the street, consists of the ground and the
paving. It can be made of a lot of different materials with both architectonic
and practical functions. The walls usually consist of the houses. They have a big
influence on the streetscape depending on architecture, heights and widths.
Betydelsen av skogens ålder och förekomst av lavar för renars val av vinterbetesområde :
This is a study on winter groups, ?siida?, of semi-domesticated mountain-migrating reindeers that move to lichen pastures in the lowland boreal forests during winter. The aim of the study was to determine reindeer habitat use in their winter ranges in a managed forest landscape. The reindeers use of three different types of forests was determined, 1) 100-130 year old, 2) 20-40 year old forest and 3) clear-cut areas. All sites were dominated by Scots pine, Pinus sylvestris, and had the same types of ground vegetation.
Förslag till vägbro vid Hössnamotet - ? Konceptframtagning och kontrollberäkning av bro över väg 40
Göteborg Energi AB är ett bolag med höga ambitioner att säkerställa ett stabilt distributionsnät för sina kunder. Med ett säkerställande följer åtgärder i form av beräkningar för komponenter som transformatorer av olika märkeffekt, hög- och lågspänningssäkringar och andra kritiska skyddsanordningar som t.ex. reläskydd. Vid ett flertal tillfällen under de senaste åren har det uppmärksammats en problematik där ett fel i lågspänningsnätet har löst ut anslutande transformator. Felet har grundat sig en svag selektivitet mellan transformatorsäkring och lågspänningssäkring.
Lättridningens påverkan på hästens rörelsemönster i trav :
The interest in horses and equestrian sport is constantly increasing, and so is the will in both riders and trainers to learn more about the effect the rider and its equipment have on the horse. The last twenty years, more and more studies have been performed were the horse and its kinematics have been in focus. The access to more advanced technology has made it possible to study areas, which earlier have been hard to reach. The knowledge about kinematics in the horse, and how riders and their equipment interact with the horse?s movement, is also of great interest to veterinarians in equine practice.
Rituellt, traditionellt eller funktionellt : en osteologisk analys och jämförelse av två förromerska gravfält från Skogome i Bohuslän och Smörkullen i Östergötland
This paper concerns a comparative analysis between two pre-Roman burial ground and the cremated individuals buried there, Skogome cemetery in Bohuslän and Smörkullen cemetery in Östergötland. The comparative analysis consists of several parts that concern both cemeteries inner and outer burial customs, and the osteological analysis of a total of 18 cremated invidvidulas. By studying the different parts separately, it has been possible to identify similarities and differences between the two contemporary cemeteries. There are great similarities between the cemeteries, differences were mainly observed in the osteological material relating to the amount of bone in each burial. The smaller amounts of bone in the graves of Skogome also holds a higher degree of fragmentation, but can not be explained by a higher combustion rate than the skeletal material from Smörkullen.
Bergsbrunna södra : analys och programförslag
This final project includes an analysis and a programme proposal for the
area Bergsbrunna södra. The area is situated along the railway between
Uppsala ? Stockholm, just south of Uppsala city. A new railway station is
planned here, which make the area attractive as residential area.
There are several values to take into consideration when developing an
area. An extensive analysis and valuation may define and protect different
characters and values, and also find the places most suitable to build
upon.
The area consists of three separate characters of landscape: the wide open
cultivated fields, the hilly wooden ground and the more varying little valley.
There are visual, cultural, social and ecological values to preserve.
The south part of the area is woods with high natural values that borders
to a national park in the natural forest of Lunsen.
The movement of the rider?s hand related to the horse?s behaviour and the stride cycle
One way of signalling commands to the horse during riding is through applying tension on the reins to create bit pressure in the horse?s mouth (Terada et al., 2006; Clayton et al., 2011). The skilfulness of the rider in using the hands when applying bit pressure has consequences both for the horse?s performance and welfare (Manfredi et al., 2010). At the trot there are large vertical deviations of the horse?s body which the rider must adjust and adapt to (Terada et al., 2006) and an unsteady hand due to inability to follow the horse?s movement can be a source of discomfort and conflict behaviour in the horse (Heleski et al., 2009).
Diversitet hos jordlöpare (Col: Carabidae) i hävdade strandnära gräsmarker :
Diversity of ground beetles (Col: Carabidae) in managed riparian grasslands.
The carabid community in moist seminatural grasslands was studied at three different sites in mid-Sweden. Pitfall trapping was carried out during six weeks in spring and early summer 2003. Eight transects, each containing seven pitfall traps, were placed in three different management regimes, either late or continous grazing, or meadow.
The species composition was analysed by ordination analyses, i.e. DCA and CCA.
Renovering av Säteriet, Råda - Från miljonprogram till attraktivt bostadsområde
The homes that were built in the 60?s - and 70's are now so dilapidated and worn that they need thorough renovations. These renovations are expensive to implement for the landlords, which means that the funding for these renovations can create problems. Currently there are no government subsidies for these renovations. This report will examine how Förbo performed the renovation of Säteriet.
Punktmolnshantering i anläggningsprojekt : Utvärdering av programvaror för framtagande av markmodell
An increased number of participants in the construction industry is asking for accompanying terrain models to the project in order to get a better understanding of the field. When the desire to create buildings that fit together nicely with the surrounding area is increasing, it becomes more and more important to have a broad base of knowledge about the ground on which the building is to be erected. Terrain models are also very useful in the planning of logistics, documentation for landscape architecture projects, and billings for mass calculations.Surveys for creating terrain models can be performed with laser scanning. The advantage of laser scanning is the time-effective surveying, the detailed information as well as the ability of application in complex environments resulting in a cost-efficient project. With this in mind our thesis was defined in collaboration with the company Bjerking AB in Uppsala in order to investigate if there were any softwares suitable for terrain modeling.
Effekten av frukostens glykemiska index på energiintag hos barn och ungdomar
Sahlgrenska Academyat University of GothenburgDepartment of Internal Medicine and Clinical NutritionTitle: The effect of the glycemic index of breakfasts in energy intake inchildren and adolescentsAuthor: Charlotte Olofsson, Cornelia Johansson and Maria NordbeckSupervisor: Fredrik BertzExaminer: Ingrid LarssonProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: May 16, 2013Background: The glycemic index (GI) and it´s effect on energy intake is a debated subject.Research has been done whether food with lower GI decreases hunger and lowers energyintake, which could be an effective tool to prevent overweight in children and adolescents.Breakfast eating is successful for maintaining a healthy weight and it´s therefore interesting tosee if the quality of the carbohydrates matters.Objective: To evaluate the scientific evidence regarding the effect of GI of breakfasts inchildren?s and adolescents energy intake.Search strategy: To find relevant articles, a systematic literature search was made in thedatabases PubMed, Scopus and Cochrane. Search terms that were used were: breakfast,breakfast quality, children, glycemic index, energy intake, obesity.Selection criteria: Randomized controlled trials and cohort trials, breakfast eatingindividuals, children and adolescents under 18 years old, reported glycemic index. Outcomemeasurements: Energy intake.Data collection and analysis: Six original articles met the inclusion criteria and werereviewed by the SBU audit template for randomized and controlled studies. There after onearticle was excluded because of very low quality of the study.