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591 Uppsatser om Peak load boilers - Sida 9 av 40

Realisering av returer vid rundvirkestransport med lastbil : hinder, möjligheter, vinster och vinstdelning

Holmen Skog, region Norrköping, is located in an area with good potential for backhauling because a large number of geographically scattered mills. However, despite these factors there are many difficulties preventing the realization of this potential. The purposes of this study were twofold. First, from a hauling contractor perspective, to calculate backhauling profits and suggest a profit sharing scheme. Second, to identify and quantify obstacles and possibilities for realization of backhauls.The study required the use of three different types of methods.

Testbänk för motorbåtsdrev

Marinediesel has, to meet there customers needs for a suitable sterndrive to powerboats, developed a prototype. The prototype is currently in the testing phase. The opportunity to test the sterndrive under load inside the workshop has not previously been possible. Until now the drive has been tested in a test bench without any load on the propeller axle. The prototype has also been tested under real conditions mounted on a boat.The idea with my thesis was to create a test bench that can run around the clock in order to be able to test things like wear and service intervals and other things that require that the test interval is long.

Konceptstudie av drivmodul till bandskotare med hybriddrift

BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.

Utveckling och dimensionering av en lastupptagande provningsram

ÅF Test Center in Borlänge had a need to expand their capacity for compressive and tensile strength tests. They wanted to do this by using a hydraulic cylinder, which they already possessed, to apply the force with. This required a load receiving structure. The aim of this work was to design and dimensioning a test bench for a cylinder marked NIKE 300 tons. The work would result in a completed design proposal on a test bench which could manage to run the compressive and tensile strength tests of up to 3000 kN.

Dämplindningens inverkan på spänningens kurvform i en vattenkraftsgenerator

Harmonics are a well-known problem that has to be dealt with in the design of thegenerator. Internationally accepted standards limits the amount of harmonics allowedin the no-load voltage. These limits can be difficult to fulfill with integral slot winding,where the number of slots per pole and phase is an integer. The presence of thedamper winding often makes the problem with harmonics even worse and harmonicswith frequencies of order 6q±1 arise with significant amplitude. How the damperwinding is designed affect the content of harmonics in the no-load voltage and the aimwith these ? has been to investigate in which extent design of the damper windingaffects the contents of harmonics.Simulations with the 2-D finite element method have showed that if the damper barsis centered in the pole shoe, the amplitude of the harmonics of order 6q±1dependsboth on the ratio between the stator slot pitch and damper bars slot pitch and if thedamper bars are connected between the poles or not.If the damper bars is displaced with ¼ stator slot pitch alternately, the amplitude ofthe harmonics of order 6q±1 is reduced and the influence of the ratio between thestator slot pitch and the damper bars slot pitch will vanish.

Utvärdering av stödgruppsverksamhet för barn och ungdomar som växer upp riskmiljöer

ABSTRACTBackground: Children and adolescents growing up in families where parents have serious problems are exposed to an increased risk of developing poor mental or physical health themselves. In a support group work they can meet other children in the same situation, receive help and support to process their emotions and manage their everyday life.Aim: To investigate if support group work at Trappan can reduce the psychological problems load and increase the experience of life quality, hopefulness and optimism in children and adolescents growing up in families where either addiction or mental illness occur in one of the parents. The purpose was also to investigate if there was any difference between these both child groups regarding psychological problems load, experience of life quality, hopefulness and optimism before and after support group participation.Method: Questionnaire study on children and adolescents of parents with addiction or mental illness. The children participated in support group work at Trappan. The measuring?s were conducted before and after support group participation.Results: In both groups an increased life quality in connection to finished support group participation was observed.

Kalvutdragaren - en hjälpande hand? :

The calf extrator?s function has been studied, through measuring traction and how this varies in different situations, in comparison with corresponding manual traction situations. This was done against the background that excessive force at assisted calvings at dystocia can mean life threatening damages on the calf such as grave acidosis, vertebral fractures, femur fractures and rib fractures. The calf extractor has earlier been measured to pull with greater force than the established maximum force of ?two strong men?.

Bilens förändrade förutsättningar i framtidens städer : en studie om aktuella förändringar kring privatbilismen i västvärlden och hur trafikplanering i Öresundsregion förhåller sig till rådande trender

Syftet med denna uppsats har varit att få en förståelse för vad pågående förändringar kring bilanvändning innebär för stadsplanering i västvärlden. Denna uppsats lämnar ingen lösning utan ska ses som inlägg i en pågående och högaktuell diskussion kring bilens roll i staden. För att uppnå detta syfte har en litteraturöversikt samt en intervjustudie med sju trafikplanerare från Köpenhamn, Malmö, Helsingborg och Lund genomförts. Bilen och dess normer har sedan 1950-talet präglat städer och stadsplanering. Bilism har i stor utsträckning bidragit till klimatpåverkan och urbanisering. Något som sin tur har resulterat i urbana fenomen som förtätning och stadsutglesning, påtagliga både i en global kontext och ner på nationell och lokal nivå.

Storjuktan ? Rekonstruktion av ett sekels kvicksilverbelastning. : En undersökning av kvicksilverkoncentrationer i daterat bottensediment.

The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg.

Analys och kontroll av hållfasthet på grenställsarm

The thesis was done in collaboration with EAB situated in Smålandsstenar. In the initial discussion faze on doing a thesis with them there was a need to analyze and ensure the strength of an existing product, cantilever racks. This included performing FEM calculations on a model and comparing the results with physical tests.EAB has two models of cantilever racks, a light duty and a heavy duty. Within the heavy duty model series there are five product variants that differ in both size and load capacity. We will be working with the product variant with a load capacity of 1000 kg/arm which is the variant that is in the middle of the series.When we started work on the thesis we did a literature study and couldn?t find any well defined methodology that integrates both product development and computer aided design analysis.

Svenska varumärkens kulturella värden

Background: Today many companies are competing to get space in our minds. Companies spend a tremendous amount of money on building strong brands. It is not just about making us aware of their logo, today it?s more about giving the brand a ?soul? and to load it with different values. Due to today?s globalization there is also interesting to look at it from a cultural perspective.

Effects of biogas residues on respiration and denitrification in arable soil : evaluation of methods, microbial activity and agronomic implications

Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.

Optimering av sintrade kugghjul

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

Momentbärförmåga för semikompakta ståltvärsnitt av HSQ-balkar : En modell för interpolering mellan eurokodens klass 2 och 3

The current standards for design of steel beams are divided into four classes based on the slenderness of cross-sectional parts. Depending on the section class a beams load capacity is either determined by a plastic, elastic or a reduced elastic model. The division between cross-sections calculated by a plastic and an elastic model is today done in a very harsh way with no smooth transition. This leads to a large difference in the calculated resistance for the sections located near the class limits. Elasto-plastic sections are in the current situation calculated as purely elastic and their large plastic reserve is not considered in the current standards.

Utredning av frekvensregleringens påverkan på mekanisk utrustning i en kaplanturbin

As a consequence of increasing wind power installations in the Nordic grid the last years, the need for regulating power has become larger. In the Nordic grid, regulating power is mainly provided by hydro power. One part of the regulating power is called frequency control, which ensures that the grid frequency is stable and close to 50 Hz.However, setting the turbine into frequency controlled operation may cause stress and wear of the components in the mechanical control system. Frequency controlling implies large and frequent servo forces and longer travelling distance of the sliding bearings in the Kaplan turbine.Based on one selected Kaplan turbine, Selsfors G1, measurements and MATLAB calculations have been performed in order to determine forces and movements of the linkage system. With these forces and movements as input, stresses and fatigue have been determined as well as sliding distances, bearing pressures and wear of bearings during a typical lifetime of 40 years.The results indicate that no severe wear exists on the bearings during 40 years of service.

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