To achieve an optimal combustion, an even air/fuel ratio in the combustion chamber is required. An optimal combustion leads to reduced amount of emissions due to a more complete combustion, which is an important matter because of the sharpened environmental laws. This can be attained, among other things, by applying entirely variable cam times. To optimize the engines efficiency and its emissions at all workloads and speeds, an active valve control can be applied. This means that the intake and exhaust-valves can be opened and closed at any time, independent of the crankshaft position.

Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.

At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause The valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark..

Because of new emission and on board diagnostics legislations, heavy truck manufacturers are facing new challenges when it comes to improving the engines and the control software. Accurate and real time executable engine models are essential in this work. One successful way of lowering the NOx emissions is to use Exhaust Gas Recirculation (EGR). The objective of this thesis is to create a mean value model for Scania's next generation EGR system consisting of a poppet valve and a two stage cooler. The model will be used to extend an existing mean value engine model.

This report contains a degree project made by the mechanical engineering students Lennart Andersson and Daniel Jansson. The project has performed in assignment by SOMAS Valves AB in Säffle. SOMAS are leading in development on control and on/off valves. To maintain this position they always want to improve their products. One way in this development is valves that are more tightened.The purpose with our project was to investigate another seat design on a HiCo (High Cobalt Alloy) seat to a SKV 150 PN 25 valve and compare this to an original HiCo seat.By modifying the seat on a ball valve we want to achieve a valve that leaks lesser then a valve whit original seat.

In this bachelor thesis, diagnostic methods for one of Siemens stem inlet control valves have been developed. The work has taken place during ten weeks at Siemens Industrial Turbomachinery AB in Finspång. The company produce steam- and gas turbines and also provides service and maintenance. The purpose with this project has been to develop diagnostic methods that oversee the health of the control valves. By using the developed methods you will know when it?s time for maintenance.

In this master thesis a robot arm belonging to an automatic milking machine from DeLaval is investigated. The robot arm is controlled by a pneumatic cylinder and a valve. The goal of the master thesis is to investigate instability problems and to find out if it is possible to solve them by using gain scheduling. Gain scheduling is a type of controller where the parameters of the controller are changed during operation, for example depending on the working point. First a nonlinear mathematical model of the system was made.

Aortic insufficiency is a very common valve problem in horses and most often affects older individuals, but nevertheless existent within younger ones. The root cause for aortic insufficiency can be varied, for example; endocarditis, ventricular septum defect or congenital valve disease but the most common are progressive valve degeneration or elite competition. Depending on the root cause, different changes can be observed on the aorta valves, but they do all have the same effect, The valves do not seal properly and blood leaks backwards. Many horses can, even with this deficiency, perform highly without any visible impacts and there is therefore no need to treat those subjects. Most often the symptoms arise at a later stage in life and they are, more often than none, put down for other reasons. In the occurrence of the clinical symptoms showing, treatment guideline is to inhibit these symptoms since The valve degeneration is presently irreversible.

The Homogeneous Charge Compression Ignition (HCCI) engine is promising in terms of lowNOx, low particulates and high efficiency. Due to its homogeneous charge, where thecombustion starts almost simultaneously from a number of points in the combustion chamber,only lean mixtures are possible to burn because of the resulting rapid combustion, which is muchfaster than the combustion in an SI-engine or a diesel engine. When richer mixtures are used thecombustion will start earlier and also be more violent.To phase the combustion later and lower the combustion speed, external cooled EGR can beused. The EGR-system used in this thesis uses a divided exhaust channel where one channel andits corresponding valve are used only for transporting EGR back to the intake system.Consequently the EGR-valve is connected to the intake pressure. This system is called Direct-EGR (D-EGR).Engine tests verified that the CA50 indeed is phased later when cooled EGR is used.

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..

As emission legislations across the world continuously pushes engine development forward,engineers constantly need to come up with and implement fuel saving technologies. During thelast decade, variable cam phasing has become a popular solution to increase gas exchangeefficiency. This configuration is typically mechanically constrained by camshaft limitations, anda solution to circumvent this problem would be to use a different valve actuation principle.One example of this is to use pressurized air controlled by electrical solenoids. Such a systemhas been developed byCargine Engineering and this provides the starting point for this work. Tobe able to operate The valvetrain on an actual engine, a control system is needed.

Myxomatous mitral valve disease is a common disease in older dogs of small- to medium-size breeds. The mitral valve, and less commonly the tricuspid valve may be affected which causes them to leak blood from the ventricle to the atrium of the heart during systole. With increasing severity of mitral valve leakage the forward stroke volume ejected into the aorta decreases, which may lead to an increase in blood pressure in the pulmonary vein resulting in pulmonary edema. A decrease in cardiac output may lead to a decrease in blood pressure, but the body may respond in order to normalize the blood pressure. Franzén showed in 2007 that the systolic blood pressure was increased in dogs with severe mitral insufficiency.

SAMMANFATTNINGNatriuretiska peptider är en är en grupp proteiner som via natriuretiska, diuretiska och vasodilaterande egenskaper reglerar vätskehomeostasen i kroppen (Levin et al, 1998). De frisätts bland annat när hjärtmuskelcellerna utsätts för stress och kan fungera som biomarkör för att utvärdera hjärtsjukdom. Analysering av typ B natriuretic peptide (BNP) i blod kan komma att vara till hjälp för den praktiserande veterinären vid diagnostisering av hjärtsvikt och även vid uppskattning av grad av hjärtsjukdom. Det har även visat sig att BNP kan användas för att uppskatta prognosen hos hundar med kronisk klaffdegeneration (Chetboul et al, 2009; Moonarmart et al, 2010).Kronisk klaffdegeneration är den vanligaste hjärtsjukdomarna hos hund och drabbar fram för allt små till medelstora hundar från medelåldern och uppåt (Kogure, 1980). Atrioventrikulärklaffarna, vanligtvis mitralis, blir nodulärt förtjockade med inlagring av glukosaminoglykaner och fibrosvävnad vilket leder till klaffinsufficiens.

Auto Deco Primer Valve är ett projekt som har resulterat i ett förenklat startsystem för tvåtaktsmotorer.Att starta en tvåtakts motor med dragsnöre är både tidskrävande och jobbigt, därför vill projektgruppen ge samhället en lösning på problemet.Genom ett befintligt koncept har syftet varit att fullborda detta system genom en ny innovativ lösning i form av en multifunktionel ventillösning. Ventilen och dess ingående system är tänkt att ersätta två funktioner som återfinns på de flesta tvåtaktsmotorer idag: Dekompressionsventil och Chokereglage Vår nya ventil gör att det tidigare manuella systemet automatiskt, och tar på så sätt bort de steg som måste utföras innan motorn startas. Det nya systemet som förverkligas i ?Auto Deco Primer Valve? kommer att medföra många fördelar som beskrivs utförligare längre fram i rapporten. Målet vid projektets slut har varit att ta fram en fungerande prototyp vilket projektgruppen har åstadkommit.Arbetet har inneburit en stor del av kreativt tänkande, för att kunna kombinera vetenskap om bland annat pneumatik med ett mekaniskt system. För att bygga ett hållbart system som klarar marknadens tuffa krav och samtidigt inte är beroende av elektricitet så har stor del av arbetet bestått av att utveckla, beräkna, dimensionera, samt förenklat systemets olika delar och sedan modellera detta i Catia V5 R20. Projektet har resulterat i en funktionsprototyp med fullständigt CAD-underlag som Husqvarna AB kommer att använda till att vidareutveckla systemet.  Med detta arbete vill vi ge samhället och framförallt skogsbranschen ett tillförlitligare hjälpmedel, genom en ny innovativ lösning, som gör att ett motorsystem för tvåtaktsmotorer blir mer driftsäkert, lättare att använda och snabbare att starta..

SAMMANFATTNINGNatriuretiska peptider är en är en grupp proteiner som via natriuretiska, diuretiska och vasodilaterande egenskaper reglerar vätskehomeostasen i kroppen (Levin et al, 1998). De frisätts bland annat när hjärtmuskelcellerna utsätts för stress och kan fungera som biomarkör för att utvärdera hjärtsjukdom. Analysering av typ B natriuretic peptide (BNP) i blod kan komma att vara till hjälp för den praktiserande veterinären vid diagnostisering av hjärtsvikt och även vid uppskattning av grad av hjärtsjukdom. Det har även visat sig att BNP kan användas för att uppskatta prognosen hos hundar med kronisk klaffdegeneration (Chetboul et al, 2009; Moonarmart et al, 2010).Kronisk klaffdegeneration är den vanligaste hjärtsjukdomarna hos hund och drabbar fram för allt små till medelstora hundar från medelåldern och uppåt (Kogure, 1980). Atrioventrikulärklaffarna, vanligtvis mitralis, blir nodulärt förtjockade med inlagring av glukosaminoglykaner och fibrosvävnad vilket leder till klaffinsufficiens.