Today's high oil prices and more stringent environmental requirements have led to that manufacturers of mobile construction equipment try to make their products more energy efficient. With this in mind a project about hybridization of hydraulic systems has been formed. The purpose of this project was to analyze the savings that can be achieved by hybridization of hydraulic systems. A reach stacker truck (Kalmar DRD450-80S4XS) were simulated in some load cases with conventional hydraulic systems and with three types of hybridized hydraulic systems. Different parts of the hydraulic systems were also analyzed separately.

Over an extended period of time there have been plans to establish a shared facility in Lennheden to extract groundwater from the Badelunda esker to provide drinking water for the cities of Borlänge and Falun. The city of Falun is dissatisfied with the quality of its drinking water and the city of Borlänge is concerned about the risk of contamination of its existing groundwater supply at its current location. To provide a basis for a decision on this issue, the company Midvatten AB has been commissioned to perform hydrogeological investigations in the area of Lennheden.The purpose of this thesis is to design a functional groundwater model of the area between Lennheden, place of planned extraction, and Övre Tjärna, place of existing extraction, to get a better understanding of the groundwater situation in the area. A groundwater model enables simulations of different scenarios in risk assessment and contaminant transport. The aim of the thesis is that the model can be used as an aid in Midvatten?s investigations in Lennheden and that it also can be used in future projects in the area.The model has been made in Processing Modflow 5.3 and encompasses an area of 19,5 × 11 km along the Badelunda esker and the river Dalälven between Djurmo and Frostbrunnsdalen.

The purpose of this master thesis is to construct a steering transmission, for a trackedvehicle, containing two hydraulic circuits which are connected. The steeringtransmission should be mechanical to avoid steer-by-wire.BAE Systems Hägglunds has in an earlier study examined a system with two hydraulicpumps and one hydraulic motor, but the safety of the system wasn?t sufficient.To achieve sufficient redundancy there must be two hydraulic motors, which arecontrolled separately. When the two systems are connected in one point, this point is acritical part of the system because it directly affects both circuits. If one of the hydrauliccircuits fails the other should be able to operate independently as a steeringtransmission.

This is the final documentation of the basis that can be the foundation of how to solve theproblem with leaking hydraulic oil in a shoe press at the company Albany InternationalAB in Halmstad, Sweden.The project has been performed at Halmstad University as a degree project commissionedby Albany International AB. The purpose of the degree project was to find a way ofdetecting the hydraulic leak of a shoe press. The reason is that the shoe press runsunattended during nights and weekends, this can cause an extensive decontaminationwork and production stop if leak. The hydraulic oil could be leaking in large amounts orslowly as a fine mist. The development of a working system that can detect a hydraulicoil leak and stop the machine before a large amount of hydraulic oil leaks out wouldconsiderably reduce the cost of the decontamination work.

Volvo Construction Equipment is a world leading company in construction machinery. Tomaintain the best products, development is prioritized. The master thesis regards sound reductionof the hydraulic system on a wheel loader. The background to the master thesis is asimulation made on the hydraulic system, performed autumn 2005. The result of the simulationshows that the energy of the pressure ripple is reduced when the paralleled hydraulicpumps are phase shifted and reduces each others pump pulsations.

Stress and time pressure is more present in todays labor markets. In financial markets a securities broker is forced to take decisions on investments under high cognitive load and under extreme time pressure. The research of decision under risk gained new ground with the development of the prospect theory and gave us new insights to the decision making of men. Prospect theory has shown that people are risk seekers when dealing with loss decisions and risk avert when dealing with profit decisions. The value function are defined over gains and losses.

Tidigare studier har visat på sambandet mellan oräddhet, psykopati,aggressivitet och antisocialt beteende. Denna studie undersöktefenotypiska och genetiska relationer mellan komponenter i the skinconductance fear conditioning task och i psykopatiskapersonlighetsdrag. Data hämtades från den longitudinella studien;Tvillingstudie om riskfaktorer för antisocialt beteende (RFAB) vidUniversity of Southern California och data från pågående tillfälle 5inkluderades i studien. Resultatet visade på betydelsen av bådegenetiska och icke-gemensamma miljö influenser förklarade varianseni obetingad respons. I överensstämmelse med tidigare forskningvisade resultaten att individer som visade på högre nivåer avmanipulativt och svekfullt beteende också uppvisade större brister irädslobetingelser..

Tidigare forskning har visat att selektiv uppmärksamhet (selective attention; SA) mot hotfulla stimuli kan predicera emotionella responser på stressfyllda händelser. Syftet med denna studie var att undersöka sambandet mellan sårbarhet för ångest i form av SA och fysiologiska samt självskattade stressreaktioner på en laboratoriestressor. Ett negativt samband mellan fysiologisk stressreaktion och SA samt ett positivt samband mellan självskattad stressreaktion och SA förväntades. Skillnaden i hudkonduktansreaktivitet (skin conductance reactivity; SCR) på subliminalt presenterade hotfulla och neutrala stimuli hos 41 försökspersoner utgjorde mått på SA i denna studie. Försökspersonerna utsattes senare för en laboratoriestressor samtidigt som hjärtfrekvensvariabilitet (heart rate variability; HRV) och hudkonduktansvariabilitet (skin conductance variability; SCV) registrerades.

Hägglunds Drives in Mellansel, Sweden, manufacture radial piston hydraulic motors foremostwithin applications in the industry. These motors have several sliding contacts, one of these, isthe contact between piston ring and cylinder bore. The radial piston hydraulic motors advantageis to produce high torque in very low rotation velocity, this result in that the maximum slidingvelocity between piston ring and cylinder bore, during the whole stroke, is very low. Theconsequence of this low sliding velocity is that the contact between piston ring and cylinderbore, during the whole stroke, is bound to the boundary lubrication regime. This result in, thatthe piston ring is exposed to wear, thus affect the service life of the complete hydraulic motor.To minimize wear of piston ring, it is essential to determine the oil film thickness between thepiston ring and cylinder bore.

Geothermal energy can be extracted from an aquifer, where the groundwater is used as heatexchange medium while heat and cold are stored in the surrounding material in the aquiferand to some extent in the groundwater. Application of aquifer storage for the use ofgeothermal energy is mainly used in large scale facilities and is limited to sites with suitableaquifers in the form of ridges, sandstone and limestone aquifers.Löwenströmska hospital in the municipality of Upplands Väsby, north of Stockholm, islocated nearby the northern part of the Stockholm esker. This means that it can be profitableand environmentally beneficial for the hospital to examine the possibilities of aquifer storagein the esker material next to its property.The purpose of this master thesis has been to investigate if geothermal energy storage with aseasonal storage of heat and cold can be applied within Löwenströmska hospital?s propertyarea using groundwater modeling. A hydraulic groundwater model was constructed inMODFLOW based on a simplified conceptual model of the groundwater system.

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.

This report treats a Master Thesis performed at Scania CV AB. The task was to create a computer model of a hydraulic actuator system in the software AVL Hydsim. The system consists of two spring-loaded masses with surrounding hydraulic components. The purpose of the model is to study phenomenon and problems in the system, as well as to be a support in the development of the system. It is not supposed to be used to study absolute values in its current form.

Hydropower is the largest renewable energy source available in today's society. Operation and production is handled by high-tech electronics. This thesis is done on behalf of Statkraft Sweden AB who wants to explore the possibility of replacing the hydraulic cylinder with an electric actuator, generally as well as a case of a small power station on the river Nissan. Whether it is the chaplain or francis turbine vanes are actuated by hydraulic cylinders. Because of Gustavsberg hydropower is inconstant operation, this report is based on power calculations, which are read and computed according to the available hydraulic diagram.

Estimation of the variation in the integrated hydraulic conductivity around the Tunåsen infiltration facility - An investigation of the effects of uncertainties in existing informationAlmost half of Sweden?s drinking water volume is produced from groundwater. The main fraction of this is extracted from eskers, some of which allow for very large extraction rates. Despite this, the groundwater volume is not sufficient in some areas. This has led to an extensive use of artificial recharge.In Uppsala, the total volume added through artificial recharge is divided between four infiltration facilities.

Dione kullager AB is a company in Uppsala, which sell industrialmachinecomponents, transmissionsolutions and provides repair serviceof hydraulic components.When a hydraulic cylinder is about tobe repaired it needs to bedisassembled. Because hydrauliccylinders usually work in dirtyenvironments and are heavilyworn some types of cylinders arealmost impossible to disassemble.Today the disassemble is made by hand,which means extra work for themechanics. In order to facilitate thedismantling of this type of cylindersa machine is to be developed for thispurpose and this is where this thesisbegins.The thesis has been organized in threephases: Literature study in whichfacts and theories are acquired.Concept generation in which differentconcepts, calculations, and solutionswere identified and selected. Thedesign phase where all the differentconcepts of components were assembledand simulated in SolidWorks. Similarstructures have also been studied inorder to identify necessary functions.The thesis resulted in a structurewhich is believed to meet therequirements.