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1117 Uppsatser om Pressure reducing valves - Sida 10 av 75

Design och optimering av lagertätning : Hos hydrodynamiska oljeglidlager med labyrinttätning

ABB Motors and Generators manufacture large AC machines with oil lubricated plainbearings. The machines have occasional problems with oil leakage from the bearings. aproblem that ABB wants to be solved.In this thesis the cause of this leakage were investigated, with focus on the bearingseals.The purpose of this work was also to suggest amndments for preventing thisproblem. , and to suggest improvements that can prevent this. The first step was todo a literature survey of earlier work on this problem, study the theory ofhydrodynamic bearings and different types of seals and their properties.

Studie av belagda kolvringarmot plasmasprutat cylinderfoder : Med avseende på friktion och nötningsmotstånd

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.

Healthier vegetables through temperature stress? : a review of Brassica oleracea

The objective of this report is to present a review of the studies which has been carried out up to days date concerning how temperature affects vegetables physiologically when it comes to their health inducing as well as quality reducing features. The essay therefore starts off with defining what is meant by the terms health promoting and quality reducing features. It then moves on to describe how different subspecies of Brassica oleracea, that is to say vegetables such as broccoli, cauliflower, Brussels sprouts and kale, is affected by temperature. B. oleracea was chosen because the species contains several commercially interesting subspecies and therefore provides a broad field even though only one species is assessed.

Kirunametoden-Jämförelse emot en konventionell injusteringsmetod

AbstractWith increasing population and increasing demands for comfort and thus an increase in energy demand, it is necessary to examine various energy-efficiency measures. This work deals with the ability to control the flow through the heating system to achieve the desired comfort with as little energy as possibleA heating system contains of different parts, roughly speaking, you can divide it to three main components: Heat source, Distribution and Heat emitters. All components are working together to bring heat to the building. What is examined in this report are different ways of adjusting the flow and supply temperature and how it affects comfort and energy use in a building.At today ?s date the conventional method is to use a high flow through the heating system, which affects pressure drop and cooling of the fluid.

Pneumatiska artificiella muskler : med hjälp av en robotarm

According to the study [1] several firefighters are killed in action each year. This happens naturally in various ways. One of the major factors is that firefighters often do not know how the environment looks like, for example that a building in an industrial area contains hazardous gas cylinders. Without a solution, fire-fighters will continue to die in duty. It is therefore important to solve this problem so that we can minimize the risks and save lives.The goal of this project was a control system for pneumatic artificial muscles.

Elevers motivation för sina studier : - och mental träning som metod för att stärka den

In 1993 the internal market within the European Union was formed and ensured free movement of goods, services, capital and people. This led to the removal of trade barriers between members of the European Union. When opening up for competition, price differences between countries decreased and more jobs were created. A single currency was introduced by eleven countries in 1999 with the goal of reducing transaction costs, eliminating exchange rate risk and to further simplify trade. In 2001 Greece joined the collaboration and introduced the euro.

En osäker eller rätt(s)säker organisation? En hypotesprövande idealtypsanalys om gräsrotsbyråkraternas handlingsfrihet inom Arbetsmarknadsverket

Ever since Lipsky wrote about street-level bureaucrats in 1980 the main belief has been that certain characteristics of their jobs make it exceptionally difficult to severely reduce their discretion. However, discretion comes at a price and if public servants abuse their power the legitimacy of government is at risk and ultimately even the democracy.This thesis address this question by analysing the Swedish employment service which in the beginning of 2001 started a project called ?Af Sverige? trying to improve internal rule of law. By comparing two local and fairly equal jobcentres and how the street-level bureaucrats within use their discretion, I seek to find support for my hypotheses that organizing local jobcentres according to the principles of machine bureaucracy plays a significant part in reducing discretion.My findings show that a jobcentre characterised by strict rules, few units, good communications and a forthright manager who delegates formal power to the employees results in a stricter and more uniform application of regulations among the street-level bureaucrats. My conclusion is therefore unambiguous.

Den djupa muskelfunktionen hos kvinnliga elitvolleybollspelare : En studie om transversus abdominis funktion påverkas av stabilitetsträning.

Background and purpose: Volleyball requires a lot of the human body, andeffective core stability is necessary for the athlete. Our muscles cooperate as achain of motions and core stabilization is the base for the moving muscles.The most well-known stabilization muscle is m.transversus abdominis (TrA).The purpose of the present study was to evaluate the function of TrA inSwedish female elite volleyball players and to observe the influence of eightweeks of stabilization exercise on the TrA. Method: 10 female elitevolleyball players (mean age 24,7 years, range 18-31 years) participated inthe study. TrA was measured in supine position with a pressure biofeedbackunit. Subjects were instructed to draw in the abdominal wall without movingthe pelvis and hold for 10 seconds.

Uttorkning av lera : Orsaker och följder

When building a house or similar the stress on the ground increases and deformations can arise. The deformations create a foundation that the building is not constructed for and damages on the building arise. The increased stress on the ground can be derived back to the building, but it is possible that the increased stress may well derive from different sources such as other buildings or trees.       The building is an older property, built in the late 19th century alternatively early 20th century, and is today used for rental housing and has suffered severe damages due to subsidence. The goal of the thesis is to find possible causes for these subsidences. The thesis was executed as a combination between literature- and casestudie. After careful studies it has been found that a probable cause for these subsidences is trees. Through field- and lab studies it has been found that the trees has effected the ground through there accumulation of water.

Undertrycksbehandling av sår ? påverkan på patientens livskvalitet och hälsa : En litteraturstudie

Introduktion: Olika typer av sår skapar stort lidande för den drabbade och Negative Pressure Wound Therapy (NPWT) är en behandlingsmetod som utvecklats för att effektivisera sårläkningsprocessen. Livskvaliteten och hälsan påverkas av såret och dess utveckling, vilket gör omvårdnaden vid sårbehandling grundläggande för patientens välmående. Syfte: Syftet var att belysa hur Negative Pressure Wound Therapy påverkar patientens livskvalitet och hälsa. Metod: Polit och Beck (2012) niostegsmodell användes för litteraturstudien. Artikelsökningarna gjordes i två olika databaser samt manuella sökningar och resultatet grundades på tolv artiklar som genomgick en kvalitetsgranskning.

Kroppsideal hos unga kvinnor i åldern 15-25 år : En kvalitativ studie av unga kvinnors syn på kroppsideal

In this essay, I have interviewed six young women about their views on body image and how their views are affected by their surroundings, massmedia and social media. Also the relationship between body image and eating disorders is relevant in this context and has a part in the study. The purpose of this study is to build an understanding of how young women relate to the body ideal that exists around them. Theoretical auxiliary tools used are George Herbert Mead's theory of the generalized other, Erving Goffman's theory of dramaturgical perspective and impression management, and Du Bois's theory of double consciousness. I have also used two scientific articles to get a deeper understanding of the subject.

Hur enkel- & dubbelportsturbin i kombination med två olika avgassamlare påverkar gasväxlingsprestanda på en Scania V8

The exhaust arrangement on a Scania V8 consists of one manifold at each bank connected to a twin entry turbine (8-2-2). A study in GT-Power has shown improved performance and reduced cylinder to cylinder variations using two manifolds at each bank in combination with a single entry turbine (8-4-1). This thesis work analyses the difference in performance shown in simulation and verify it by engine test.The initial work was focused on simulation in GT-Power. Investigating how exhaust manifold volume and pulses effects the turbine efficiency and the mean effective pressure during the gas exchange. To verify GT-Power simulations four engine tests with different exhaust arrangement have been made.The results from GT-Power simulation indicate that a larger exhaust volume improve the turbine efficiency.

Drivkrafter och barriärer för Green supply chain management inom offentliga organisationer

The purpose of this paper is to analyze the driving forces and barriers which may exist at the implementation of green supply chain management (GSCM) within public organizations. Suggestions that may increase or reduce driving forces and barriers to public activities will also be provided, where such is found. The background of the study is that the public sector is such a major customer for many companies / providers, which makes the sector able to highly affect its suppliers. This essay is based on literature studies. The results showed that GSCM is a relatively unexplored area, especially applied on the public sector.

Halvledarreläer

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

Vad skapar stress respektive trivsel hos avverkningslag? : en jämförelse mellan bolags- och entreprenörslag

As a student during my studies, I have been told about entrepreneurs who have red numbers in their financial statements, and there is a forest machine operator shortage in Sweden. The basic idea of this thesis was to examine the underlying factors that may have caused the problems described above. The aim of this thesis was to investigate the factors that create stress and job satisfaction as a forest machine operator. The study was performed as a comparison between forest companies own harvesting teams and entrepreneur teams to investigate if there are any differences in stress and job satisfaction between the two different types of team. The study was conducted in collaboration with SCA Skog. The material for this study was collected by doing interviews with SCA's harvesting teams. A total of 27 forest machine operators were interviewed, divided into a total of 10 separate harvesting teams. It was very similar between the different type of teams, which situations the operators experienced stress.

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