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.

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.

Detta examensarbete har genomförts på begäran av byggnadstekniska byrån i Uppsala. Företaget behöver en ny beräkningsmall med vindlastberäkning för väggar och olika taktyper enligt Eurokod.I dagsläget använder företaget en beräkningsmall som är baserad på gamla normer enligt BKR. Dessa normer kan dock inte användas längre enligt nya bestämmelser inom branschen. Enligt de nya bestämmelserna bör dessa vindlastberäkningar genomföras med hänsyn till Eurokod i framtiden.För att kunna beräkna vindlasten enligt Eurokod och effektivisera beräkningsgången har man utvecklat en beräkningsmall baserad på Eurokod. Alla nödvändiga parameterar enligt standarder har använts i beräkningsmallen och användaren tillåts genomföra en snabb och enkel inmatning av projektmått för att på ett automatiserat sätt genomföra belastningsanalysen.

The governing set of regulations for structural engineering in Sweden used to be Boverket, BKR. However in the beginning of the 21st century a changeover to new regulations, the Eurocodes, started.The transition was completed in year 2011 when the Eurocodes became the mandatory design work policy for all countries within the European Union. The Eurocodes were implemented to simplify and remove potential barriers to trade that may exist when countries have different design rules.  Since the changeover it has been important for all construction companies to update their knowledge base and their design software.When comparing the two calculation processes they seem similar, but there are a couple of differences worth noting.  With the new regulations, engineers will find that the process when designing joints in timber structures has changed.  What used to be a fairly easy and straight forward calculation procedure has now become tedious and time consuming.The objective of this degree project is to present a product, a dimensioning tool that will help structural engineers when computing lateral load carrying joints in timber structures.The degree project is made up of two parts where the first part is the written report describing the background and theory behind load carrying computations. The second part of the project is the actual dimensioning tool which includes several worksheets in Microsoft Excel. The program treats single and double shear connections of the following:Nail jointsScrew jointsSteel plates (thick and thin types) The user can edit the following parameters:Type of plate/ number of shearsStrength class of timber membersMember and plate sizeType of fastenerDiameter of fastenerLength of fastenerYield moment of fastenerkmod and partial factors for design load carrying capacityThe dimensioning tool was created and developed in collaboration with structural engineers at the company Byggteknik AB.

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.

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.

In inhalation anesthesia life-support systems are used to provide gases to the patient and to monitor important parameters. These systems are used in dynamic and stressful situations where the information-load on the operators often is significant. This thesis presents a design concept of an anesthetic system. The design goal has been to keep the information-load on the operator low with the objective to minimize confusion and error.A number of contextual inquiries were made in the operating room during surgery at four hospitals in Sweden. The goal was to understand the actual use-situations when anesthetic systems are employed.

This thesis intends to analyse conditions for a successful implementation of consociational democracy, as a democratic model in Afghanistan. The lack of critical reviews regarding the democratisation-process in Afghanistan initiated the purpose of this study.Lijpharts democracy model was used as the basis in the comparative study. Along with empirical evidence regarding how the complex process of democracy in Afghanistan is progressing, the study investigated whether the identified conditions occurred or not.The choice of which democracy model to use can be crucial for the democratic possibilities to even survive and become established in conflict-affected communities. The principle of consociational democracy is that it is an empirically based normative model that aims to organise the state in a way that works against the risks of majority domination and oppression against the minority.The empirical case study revealed that a majority of the conditions were not met, which then can counteract the possibilities for consociational democracy in Afghanistan. The study has critically examined the prospects for the success of consociational democracy in Afghanistan, and it can be assessed that there is a limited probability for a successful applying of this model..

From 1710 to 1713 the plague raged through the Swedish province of Scania. Other studies have been made on how the disease affected the society during the epidemic. This study tries to focus on the recovery afterwards. How did the population and the farmsteads recover after the plague? Statistics from parish registers and cameral records show interesting patterns in the demography, and that the recovery was far from complete 1720.

This thesis raises the problem with acid mine drainage around the closed mine Finngruvan.The purpose of the investigation was to compare metal content in surface water in the areaand its catchments between year 2010 and 2003, also to make calculation of specific runoffand metal load, furthermore determine the recipients in the area. Surface water samplingwhere preformed at the same place as 2003 and also at a few other places of interest. Adigital elevation file were used in GIS to calculate the area of the watersheds in the region,observations in the field where also made. The collected data were used to make comparisons,calculations and conclusions. The result showed that the surface water 2010 had somewhatlower metal concentrations.

In times of increased flooding, enhanced by climate change, polluted stormwater poses an increased threat to the environment through contaminated water entering waterways. Bioretention utilizes natural processes in soil and vegetation to treat pollutants and combat this threat. Biochar produced through pyrolysis, has a high cation exchange capacity (CEC) and could therefore increase treatment in bioretention systems. This research applies a literature review, interview, and a model to explore the benefits and disadvantages of biochar in order to specify a soil-mix through an understanding of the production process and preferred application rate. High purification through CEC, increased water holding capacity, and carbon sequestration being the benefits discussed.

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

GE Healthcare operates in Uppsala (Sweden) and develops systems, equipments and medium to purify medical substances. Discussions with the local authority concerning planed far-reaching changes and upgrades of the biological process techniques for sewage management, aroused the question about revising the terms of permit for the activity. Therefore it seemed necessary to evaluate a newly installed biological process technique, which is the background of this thesis. The evaluated biological treatment process was built in 2003 and consists of a biological reactor filled with moving bed carriers with a high surface area for biological growth. At the time of the project the biological wastewater treatment plant consisted of a flow equalization facility and two following parallel biological processes; a biological reactor with moving bed carriers and a tower trickling filter.The aim of this thesis was to survey the function of the biological reactor with respect to the reduction of organic matter.

Listed corporations achieve effectiveness through segmentation of investors. Categorization of like- minded investors diminishes goal incongruence. This thesis aim to examine an Investor models accuracy, provided by a Professor Emeritus in Economic Psychology in 2001. This model segments investors as active, passive, speculative and naive investors. This thesis has a demarcation to private investors on the Swedish stock market. It has a deductive and qualitative approach as the purpose is to study the Investor model.

Simulation means running a model of a system with suitable input and observing the corresponding output. Real-time environment simulation is a special kind of simulation used to simulate a control system's environment in real-time. This is done to test the control system before it is used in its real environment. In this project, computer simulation of a certain kind of environments, called track-based systems, is studied and a general model for track-based systems is developed. In this model, track layouts are represented by graphs, which is a flexible and extensible representation and a method for visualizing these layouts is presented.