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801 Uppsatser om Adaptive pressure - Sida 5 av 54
Numerisk simulering av hydroformning
Sedan hydroformning började användas inom plåtformning i början av 90-talet har den dragit mer och mer uppmärksamhet till sig framför allt inom bil- och flygindustrin. Processen kan med fördel användas istället för konventionell teknik dvs mekanisk stansning eftersom den kan skapa delar med bättre egenskaper till lägre kostnad. I hydroformningsprocessen pressar en hydraulisk vätska ut ämnet mot formen samtidigt som cylindrar trycker på vid ändarna av ämnet för att tillföra material där det behövs. Förhållandet mellan vätskans tryckökning och cylindrarnas axiella kraftökning är en mycket viktig del i processen. Två versioner av finita elementprogrammet DYNA3D användes för att simulera processen: en standardversion och en version med en adaptiv tryckökningsalgoritm.
"Är jag tillräcklig?" : - Diakoners hantering av möjligheter, begränsningar och inre konflikter
In a press release from the Swedish church it says that the pressure from people who are in need is increasing on the deacons in Sweden and that it?s getting higher each year. This study contains the search of knowledge about the deacons of the Swedish church, if they actually feel an increasing pressure and in what way, how they are handling the possible pressure from people in need, if that pressure is too high and if the deacons feel that they can assist the people seeking their help. The study also aim to provide more knowledge about the deacons experiences of the opportunities and boundaries (or obstacles) they meet in their line of work and how they handle the boundaries when/if they can?t provide the help that the people need.
Smart Control : En reaktion på EU:s ekodesignkrav
The purpose of this thesis is to assist the Swedish energy company NIBE Energy Systems in their studies of adaptive regulation applicable to electrical water heaters. Due to coming energy classifications of these appliances in the European Union, NIBE Energy Systems needs to use adaptive regulation, called Smart Control, to keep their products in the best possible energy class and remain competitive to the market. By using this Smart Control regulation a 2-3 % improve-ment of efficiency can be credited the system. This is a small number, but heavily needed, since the energy classes are based on the idea that the European Union is provided with electricity from coal condensate power resulting in a 40 % maximum efficiency. Furthermore, doing noth-ing will result in some water heaters not being approved to use on the market from 2015 due to low efficiency.
Processdatorsystem för tryckreglering
The task of this project was to build an computer processing system for pressureregulation, in which the pressure loss over the open hydrolicvalve should be kept as low as possible. By using an cross connected proportional directional valve the valve problem could be solved. The control- and regulationproblem for the pressureregulation system was solved by using the DAQ- card NI6035E from National Instruments and the computerprogram Automatic Pressure Control 1.0 which has been software developed and written in Visual Basic. The final result showed that correct processvarible was obtained in 0,5 seconds, when the setpoint was changed in the testarea 0 - 2,5 MPa..
Drivaxeltrycksreglering hos tunga fordon : För en ökad framkomlighet vid vinterförhållanden
Heavy duty vehicles often have problems with traction during the winter periods. For vehicles that can lift tag axles it is possible to increase the normal force on the driven axle by lifting one or more tag axles, this will then increase the propulsive force of friction. This however increases wear on both road and vehicle. A possibility to reduce the wear while achieving nearly equivalent traction compared to lifted tag axles is to allow the vehicle to regulate the normal force by lowering the pressure in the air suspension associated with the tag axles or by the lifting of these axles. The vehicle would then by itself be able to set just the right amount of normal force on the drive wheels to avoid unnecessarily high normal forces while maintaining sufficient traction.The purpose of the report is to find out which parameters affect heavy duty vehicles when driving on slippery slopes and how traction can be improved.
Modellering och simulering av det evaporativa bränslesystemet i en personbil
This thesis work has been performed at the department of diagnosis and dependability at Volvo Car Company, Torslanda. The background of this project is based on interest in ascertaining how different factors possibly can affect a diagnosis method, which has been developed to find leaks in the fuel tank and evaporation system. According to the OBD II requirements leaks with an orifice diameter larger or equal to 0,5 mm, must be detected. The idea of the diagnosis method is to create an over pressure in the system with an air-pump. The current through the pump is measured and correlates to the power consumed by the pump.
Dynamic obstructions of the equine upper respiratory tract
Dysfunction of the upper respiratory tract is a common cause of impaired performance and intolerance to exercise in racehorses and include several upper airway obstructions. The ones termed dynamic obstructions are primarily seen during physical exertion and affected horses often appear to be normal during endoscope examination at rest. The correlation between diagnoses made at rest respectively exercise is low, suggesting that an examination at rest alone is likely to be insufficient.
The upper respiratory tract is exposed to great differences in pressure throughout the respiratory cycle; variations that are further altered during strenuous exercise and affect the rigidity of upper airway structures. In presence of great fluctuations in pressure, stability is achieved through coordinated and synchronous neuromuscular mechanisms. Due to nerve damage or anatomical abnormalities, these functions may be disrupted and further cause a dynamic collapse of the upper respiratory tract when pressure changes become too severe.
The etiology behind the neuromuscular dysfunction is not yet fully understood.
Ett mät- och reglersystem för temperaturkompensering
An automatic control system for calibration of pressure indicators has been constructed. This control system can be used as a complement to the calibration system located at AerotechTelub, division MainPartner, in Linköping. The calibration system used today contains some not wanted pressure changes, which is compensated by hand today. The new system presented in this report automates the calibrating process and simplifies the calibration. Suitable hardware as motor, controls card and so on have been found and software in the form of Visual Basic program has been developed.
Simulation of rattan harvests in Indonesia : different harvesting pressures and the resulting patterns
The objectives of this research were to determine whether the natural rattan resources in Sulawesi, Indonesia can cope with the strongly increased harvesting pressure that has occurred over the last centuries. I was furthermore looking for patterns in the rattan population dynamics that might give a hint on how the harvesting system could be improved to ensure a maximum sustainable yield. To
answer these questions, I developed an individual-based model to analyse the dynamics of rattan growth in connection with rattan harvests by locals to identify sustainable levels of rattan harvests around villages in Sulawesi, Indonesia. Scenarios with different harvesting intensities were run to compare the change in harvest amount. For a given harvesting pressure, scenarios with a high number of harvesters and a low harvesting frequency had the same effect as scenarios with high harvesting frequencies and a low number of harvesters.
Expansionsmaskiner istället för strypventiler - en effektivisering
In Uppsala CHP Plant, there are six pressure reducing valves to reduce the pressure from 15 to 3 bars, before six absorption heat pumps. During the process the energy is conserved but losses occur in form of exergy. The aim of this thesis is to reduce the losses of exergy. This can be done by letting turbines replace the pressure reducing valves.In this thesis an investigation has been done of the conditions today, the conditions after the change from pressure reducing valves to turbines and a comparison of three different types of turbine solutions. The three examined solutions are one turbine, several helical screw expanders and several small turbines in parallel with asynchronous generators.The six absorption heat pumps have been divided into two groups; one group of four and one group of two absorption heat pumps.
Evaluation of indirect blood pressure measurement, plasma endothelin-1 and serum cortisol in clinically healthy horses
Equine metabolic syndrome (EMS) it?s a clinical condition that includes obesity, regional adiposity, insulin resistance (IR) and laminitis. A similar syndrome exists in human medi-cine, the metabolic syndrome (MS), were systemic hypertension also is a prominent fea-ture. The systemic hypertension seen in humans with MS is partly due to a vascular endo-thelial dysfunction with an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in EMS as well but if ET-1 is involved in the development of the systemic hypertension in horses is not known.
Stump treatment with the root rot antagonist phlebiopsis gigantea : - sensitivity of P. gigantea spores to high pressure stress; - reduced water consumption for stump treatment
Stump treatment today requires large quantities of clean water mixed with the protective product Rotstop, to fully cover the stump surface. In order to reduce the
water consumption without reducing the coverage of the stump surface, the pressure in the stump treatment device can be increased. Therefore, the Phlebiopsis gigantea
(Fr.) Jül. suspension used as a biological control agent to prevent Heterobasidion annosum (Fr.) Bref. infection was pressure-tested.
Kollektivt lärande i kunskapsföretag
Background: For the knowledge company the employees? competencies and knowledge are important assets. According to this, there has been a lot discussion about how to best take advantage of the employees? knowledge and create organizational learning. This organizational learning can be difficult to create due to the individuals? own goals and the fast changes in today?s society.
Prehospital vätskebehandling vid stort trauma ur en sjuksköterskas perspektiv : En systematisk litteraturstudie
The aim of this study was to determine which type of fluid to use in trauma care to improve patient survival. The method used was a systematic review, where a total of 18 studies were reviewed and 13 included in the results. The inclusion criteria used in this study were Randomized controlled trial, or studies relevant for the purpose, written in English and published during the last ten years. The studies were identified in the PubMed data base. The results showed that in trauma with hypovolaemia, colloid infusion has a better effect than infusion of crystalloid fluid on blood pressure and colloid infusion reduced the body's cascade systems in a beneficial way. Colloid infusion administered to head injury patients lowered their intracranial pressure more than crystalloid infusion.
Nordisk compliance - En studie av de nordiska EU-medlemmarnas implementeringsnivå
The following thesis is examining compliance with EU-law from a member state perspective. The variation in the compliance level between the member states from 1995 to 2005 is analyzed to prove the fact that the Nordic member countries during the measured time period experienced a low number of infringements. The infringements that did occur were resolved faster and more efficient in the Nordic countries then in the other member states. The theory used to explain the Nordic compliance rate is divided between external and internal pressure in a pull and push model. The external pressure is illustrated with argumentative persuasion from the EU-commission to the individual member states; how the state responds to the persuasion in order to act compliant.