District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

There are many aspects which must be taken into consideration when studying individuals? need of exercise. The study investigates if impulsivity and Health Locus of Control affect the continuity of physical practise. The main presumption was that individuals with high impulsivity, high Powerful Others and high Chance Health Locus of Control, would have a significantly harder time to maintain a continuous physical activity. The survey used two standardized tests to measure impulsivity and Health Locus of Control and in order to be able to measure the insensitivity and the periodicity of physical exercise, a test was developed by the authors.

Performance of an intersection affects the total travel time in a traffic network. An intersection with good performance can easily be described by its contribution to lower travel time than in a comparable intersection. The travel time is of importance in the cost calculations when a specific intersection is to be chosen and designed. It is important to be able to make correct and precise performance calculations so that the cost calculations will not be incorrect. For that purpose the software Capcal, which is a traffic model for intersection analysis on performance, is used in Sweden.

Detta examensarbete har varit att ta fram ett koncept för ett second-screenlager till företaget Headwebs filmuthyrningstjänst. Denna rapport visar på hur tre second-screenfunktioner kan appliceras i en video on demand-tjänst. De tre funktionerna som applicerades var att som användare via sin second-screen välja på vilken enhet man vill se sin film, kontrollera filmens playbackkontroller och välja ut små filmklipp från filmen och dela dessa på sociala medier.Resultatet blev ett lo-fi-prototyp som visar hur de tre funktionerna kan appliceras på Headwebs iPadtjänst och listar för- och nackdelar med de olika konceptet..

The study examines the price elasticity of demand for cigarettes in the short- and long run in Sweden. The time period for the study is 17 years and covers the years 1996-2012. The results of the study shows that the price elasticity of demand for cigarettes in the long run is higher than in the short run for the Swedish consumers, which is in line with previous studies in the area. The fact that the price elasticity of demand for cigarettes is higher in the long run, indicates that the substitution effect has a significant impact on the price elasticity of demand for cigarettes in the long run. The study was conducted in two parts where the authors investigated the effect of cigarette tax on cigarette prices and in addition the cigarette prices impact on the demand for cigarettes in Sweden.

In the recent years auditing scandals all around the world, deficient internal control has attracted a lot of attention. This has contributed to further requirements on insight and internal control. Those scandals have seriously damaged the auditor?s profession and contributed to a reduced trust among the public. Therefore an extensive work to recover and stringed the trust was started all around the world.

The aim of this essay was to obtain an understanding about company owners thinking about the connection between having an own company, and the risks for an alcoholic abuse. The risk factor I was researching was stress, alcoholic culture, accessibility and rehabilitation.I have interviewed five owners of small companies, two women and three men, which represents four different kinds of branches. The theories I used in analysing the empirical findings where the theories of psychosocial work environment of Lazarus, Karaseks demand/control model, epidemiology- and culture perspective.I have found that the main stress factors for company owners where the economical stress and great load of work. The stress was also related to the fact that company owners of small companies often were alone with all the responsibility and problems.Women did not use alcohol very often as a tool to reduce stress. If individuals were using alcohol to reduce their stress, it also had to deal with their ability of coping and also what channels they had for coping..

Deicing fluids based on Propylene glycol are used at Stockholm Arlanda airport to remove or prevent ice on aircrafts. The high oxygen demand of propylene glycol can cause oxygen depletion in rivers downstream from the airport if not collected. Mass balance calculations made by Swedavia indicate that the actual amount of gathered propylene glycol is underestimated. Suspicions that propylene glycol is degraded in the stormwatersystem designed to collect deicingfluids, called the B-glycolsystem, have to be investigated in order to establish with certainty that no propylene glycol in other ways leaves the B-glycol system.The purpose of this study was to determine if degradation of propylene glycol is present in the B-glycol system and also to estimate the extent of the degradation. Propylene glycols high biological oxygen demand can cause oxygen depletion in waters downstream from Stockholm Arlanda airport if not collected.

Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.

The Swedish consumption of lamb a increasing, and today we yearly eat a kilo of lamb per person each year. As a consequence the Swedish degree of self production according to lamb is steadily decreasing, and is today about 39 %.Today Swedish Meats is now cooperating with the Swedish lamb breeders organisation to raise that percentage. At the same time the European Union presents a new agricultural reform, the MTR (Mid Term Review). The shape of this new reform is not yet fully known, but the general policy has been more or less outlined. The new reform is split into three propositions: the farm model, the regional model and the mixed model.

An organization must manage its resource consumption and material flows in order to satisfy the demand of its products as efficiently as possible. Managing of the aforementioned requires a balance between the organizations resources (such as the capability of distribution and production) and the market demand. According to Gardner (1990), an estimation of future demand is a necessity for maintaining the balance. An instrument that is used frequently to estimate future demand is demand forecasting. The demand forecasting practice has been thoroughly studied and a plethora of academic contributions exist on the topic.

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

In order to facilitate trade between EU members, the European Committee has created regulations that will govern supervision of organic products. Every regulatory agency shall, according to the European Committees regulations, carry out a risk classification of each organic producer they regulate. This study for The National Food Administration compares regulation of Swedish organic products with other countries, and aims to produce a simplified model based on risk that can be the beginning of the risk classification model that Sweden in the current situation don?t have. The thesis is based on three questions: 1) What criteria should we use for assigning organic food producers? 2) How do selected European countries and frontrunners rate organic producers and what can Sweden learn from them? 3) How might a national classification model of organic production look in order to ensure an equivalent level of regulation and prevent competition among private inspection bodies? A review of information gathered from the different countries gave differing results.

Aims The aim of this study was to investigate how personnel within food control are regarded from different perspectives and to find the answers to the sub questions:- what is included in the profession of food control?- what are the requirements for personnel within the profession of food control?- how is the profession perceived from different perspectives?- how do personnel within the profession of food control estimate their psycho social working conditions?Method The study included 68 individuals (34 female and 34 male) and was conducted via observations, web-based surveys and survey-based interviews. Conclusion - The study was feasible.- The overall goal of the study as well as the research questions were answered to and contributed to clarify what is included in the profession of food control. - Quality measures should be implemented to greater extent within the development of the national food control system..

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.