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5564 Uppsatser om Model for an effective in-plant logistic - Sida 24 av 371

Development of Liquid Cooling for PCs

In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.

Förändringarna i den tyska familjepolitiken : Ett steg bort från den konservativa välfärdsmodellen?

The purpose of this paper is to analyze the ongoing changes in German family policy. It explores the issue of whether the German welfare state, in this policy field, can still be regarded as a conservative welfare model or rather approaches a more liberal or social democratic model. A qualitative method is used to analyze the material, especially from the German government, including press releases, other public documents and also articles from the political weekly magazines Der Spiegel and Die Zeit. The changes analyzed are the new parental benefit, the expansion of child care, the concept of whole-day schools and the system of joint taxation. The point of departure is Gösta Esping-Andersen?s categorization of three types of welfare states: the social democratic, the conservative and the liberal.

Beslutsmodell för inköp och lagerhållning av motorer i ett produktionssystem : En fallstudie på Sandvik

AbstractIt is important to choose which spare parts to keep in stock. With the right spareparts in stock the costs for inventory and production loss will decrease. Cavalieri et al. (2008) highlights that the balance between inventory cost and production loss is underestimated.  It affects the company and must be considered before decision on purchase.The problem with spare engines is that they are all more or less critical for the production. That can be a reason for why no previous research targeting engines and classification of with engine should be kept in stock has been found.

Total organic carbon (TOC) and chemical oxygen demand (COD) - Monitoring of organic pollutants in wastewater

Total organic carbon (TOC) and chemical oxygen demand (COD) are two methods used for measuring organic pollutants in wastewater. Both methods are widely used but the COD method results in production of hazardous wastes, including mercury.The purpose of this study was to validate the method TOC that will replace COD and find a factor to convert TOC to COD. In this study 26 samples were analyzed from four sewage treatment plant in the municipality of Enköping.The results show that the COD method could be replaced by the TOC method.The factor for COD/TOC was between 3.1 - 3.3. Both methods will be used in parallel until 2013 when it will be forbidden to use the COD analysis..

Undersökning av processparametrar för optimering av sol-gelprocessen för produktion av kärnbränsle

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Kvarnkretssimulering för test av styrsystem

This thesis has been carried out in autumn 2009 at Uppsala University for Boliden Mineral AB. Physical modelling has been used to model a comminution circuit. The model has then been linked to a PLC.When a concentrator is about to become operational Boliden Mineral AB have been looking for a way to test the PLC. The purpose of this report has therefore been to develop models for the subprocess in a concentrator and link these models to the PLC. The subprocess was a comminution circuit in Aitik36.

Observatörer för skattning av verktygspositionen hos en industrirobot : Design, simulering och experimentell verifiering

This thesis approaches the problem of estimating the arm angles of an industrial robot with flexibilities in joints and links. Due to cost-cutting efforts in the industrial robots industry, weaker components and more cost-effective structures have been introduced which in turn has led to problems with flexibilities, nonlinearities and friction. In order to handle these challenging dynamic problems and achieve high accuracy this study introduces state observers to estimate the tool position.The observers use measurements of the motor angles and an accelerometer and the different evaluated observers are based on an Extended Kalman Filter and a deterministic variant. They have been evaluated in experiments on an industrial robot with two degrees of freedom. The experimental verification shows that the state estimates can be highly accurate for medium frequency motions, ranging from 3-30Hz.

Materialdistribution i ett tillverkningsföretag : en fallstudie av PartAB

The purpose of this project is to study Partab's material distribution process, furthermore identify critical problem areas within the company. Further the aim is to provide suggestions to new work procedures regarding material distribution and related processes. Appropriate literature has been used as a support in this process. The main goal of a commercial company is to generate cash flow, and maximize the return on investment. Streamlining material supply and the use of material is a part of this process. Virum and Persson define logistics as: "Logistics is the approach and principles founding the process of planning, development, coordination, organisation, management, and control of material distribution from supplier to user".

Geotermi i Ungern : Undersökning av Ungerns energisituation inriktat på geotermi samt kapacitetsfaktorn för det största geotermiska värmeverket i Mellaneuropa.

Hungary?s share of renewable energy in 2010 was 7.9 %, and their renewable energy goal for 2020 is 14.65 %. Geothermal energy is one option that could help to achieve the goal, since Hungary has favorable bedrock, the temperature gradient is above average and thepermeability is high. Today Hungary is importing just over half of its primary energy supply. Because of political conflicts between nations Hungary wants to expand its own production of energy.

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.

Effekten av massagebehanling vid hypertoni : en litteraturstudie

Aim: The aim is to create a review that examines different forms of massage therapy and their effects on hypertension.Method: Literature review of 10 scientific articles on the subject of massage and its effects on blood pressure. The literature searches were made with PubMed and Cinahl using the keywords "massage therapy", "effects" and "blood pressure".Results: The articles showed that massage had a positive effect in lowering blood pressure. This could be explained by greater extent of relaxation in the participants investigated and an increased activity of parasympaticus and reduced secretion of stress hormones. The articles do not agree on what form of massage therapy is most effective in lowering blood pressure and it is uncertain for how long the effect can remain.Conclusion: Massage is usually seen as a treatment without scientific basis. There is evidence that suggests that massage therapy is an effective treatment for lowering blood pressure.

Se mig, inte bara min cancer! : En systematisk litteraturstudie om bröstcancerpatienters upplevelser av möten med vårdpersonal.

Aim: The aim is to create a review that examines different forms of massage therapy and their effects on hypertension.Method: Literature review of 10 scientific articles on the subject of massage and its effects on blood pressure. The literature searches were made with PubMed and Cinahl using the keywords "massage therapy", "effects" and "blood pressure".Results: The articles showed that massage had a positive effect in lowering blood pressure. This could be explained by greater extent of relaxation in the participants investigated and an increased activity of parasympaticus and reduced secretion of stress hormones. The articles do not agree on what form of massage therapy is most effective in lowering blood pressure and it is uncertain for how long the effect can remain.Conclusion: Massage is usually seen as a treatment without scientific basis. There is evidence that suggests that massage therapy is an effective treatment for lowering blood pressure.

Optimal design av strukturer - Utvärdering av problem och lösningsförslag inom topologioptimering

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Missilstyrning med Model Predictive Control

This thesis has been conducted at Saab Bofors Dynamics AB. The purpose was to investigate if a non-linear missile model could be stabilized when the optimal control signal is computed considering constraints on the control input. This is particularly interesting because the missile is controlled with rudders that have physical bounds. This strategy is called Model Predictive Control. Simulations are conducted to compare this strategy with others; firstly simulations with step responses and secondly simulations when the missile is supposed to hit a moving target.

Ekoanalys-modell : En förenklad modell för att kunna belysa miljöpåverkan redan i designstadiet av en produkt

The environmental debate is more intensive than ever before and the demands on companies increase. There are a number of methods to make it easier for the companies to fulfil the demands. Life Cycle Assessment (LCA) end ecodesign are some of the methods that can be used. Syntronic AB has the possibility to reduce the products´ environmental impact in the design phase. Therefore it is important for the company to make it possible to visualize the negative environmental impacts a product can cause in an easy way. It is also important to visualize for there clients if any improvement is possible. The purpose of this thesis is to develop a simplified model.

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