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A Scania 13 1 engine modified for single cylinder operations was run using nine fuels in the boiling point range of gasoline, but very different octane number, together with PRF20 and MK1-diesel. The eleven fuels were tested in a load sweep between 5 and 26 bar gross IMEP at 1250 rpm and also at idle (2.5 bar IMEP, 600 rpm). The boost level was proportional to the load while the inlet temperature

The current research focuses in understanding how inlet pressure, EGR, combustion phasing, engine speed and pilot main ratio are affecting the main parameters of the combustion (e.g. efficiency, NOx, soot, maximum pressure rise rate) in the novel concept of injecting high octane number fuels in partially premixed combustion. The influence of the above mentioned parameters was studied by performing

Using alternative fuels like Natural Gas (NG) has shown good potentials on heavy duty engines. Heavy duty NG engines can be operated either lean or stoichiometric diluted with EGR. Extending Dilution limit has been identified as a beneficial strategy for increasing efficiency and decreasing emissions. However dilution limit is limited in these types of engines because of the lower burnings rate of

The behavior of Ethanol and seven fuels in the boiling point range of gasoline but with an Octane Number spanning from 69 to 99 was investigated in Partially Premixed Combustion. A load sweep was performed from 5 to 18 bar gross IMEP at 1300 rpm. The engine used in the experiments was a single cylinder Scania D12. To allow high load operations and achieve sufficient mixing, the compression ratio w

Finding the correct top dead center (TDC) offset for an internal combustion engine is harder than it seems. This paper introduces a novel method to find the TDC offset based on a simple assumption that the heat loss power through the combustion chamber walls is constant for motored cycles in a narrow crank angle interval around TDC. The proposed method uses nonlinear least squares optimization to

It is tractable to increase the torque for an HCCI engine and one way is to add a turbocharger. Operating in HCCI mode requires accurate control of the combustion phasing, CA50. The higher the engine torque, the narrower the CA50 window becomes where HCCI operation is maintained. As the CA50 varies stochastically between cycles this requires improved CA50 control for turbo HCCI engines. The main f

By using a turbo the operating range of the HCCI engine can be increased, but at the expense of increased controller complexity. The dynamics the turbo introduces in the intake and the exhaust manifolds, have a large impact on the in-cylinder mixture temperature, pressure and finally the combustion phasing. To compensate for this and to maintain desired combustion phasing, precise control of the n

For diesel engines the major exhaust problem is particulate matter and NOx emissions. To reduce NOx, exhaust gas recirculation (EGR) is often used. The behavior of the EGR-level will therefore influence the emissions and it is therefore valuable to keep track of the EGR-level. Especially during transients it is difficult to predict how the EGR-level varies. In this paper the CO2-level in the intak

Partially Premixed Combustion (PPC) is a combustion concept by which it is possible to get low smoke and NOx emissions simultaneously. PPC requires high EGR levels and injection timings sufficiently early or late to extend the ignition delay so that air and fuel mix extensively prior to combustion. This paper investigates the operating region of single injection diesel PPC in a multi cylinder heav

We demonstrate the design, manufacture, and characterization of an X-band waveguide filter using 3D printer technology. The permittivity of the PLA plastic used in the printer is measured to be 2.3 - 0.01j, with about 4% uniaxial anisotropy. The manufactured filter consists of seven dielectric slabs interspace by air. Measured and simulated results agree very well, which shows the possibility of u

Popular Abstract in Swedish Avhandlingen behandlar äganderättens skydd enligt Artikel 1 första tilläggsprotokollet till Europakonventionen om de mänskliga rättigheterna.The Nordic constitutions secure the right to property. A fundamental issue under the constitutional provisions guaranteeing the right to property has traditionally been how to distinguish between interference with property rights which come under their scope and those which do not and hence in principle do not enjoy any constitutional protection. This approach has its counterpart in American const

This paper deals with far field effects of random errors in antenna applications, for instance due to manufacturing tolerances. The canonical problem is to study expressions that represent the far field power pattern from a collection of sources with far field amplitude. In this paper, the author shows that it is possible to derive quite general results from an arbitrary probability distribution,

This study investigates the impact of childhood health on labor market outcomes. We used type 1 diabetes as an instrument of health because its cause is multifactorial and it is triggered by a complex combination of genetic and environmental components; its incidence is low and unforeseeable for the individual; and its onset may be considered an exogenous health shock. Using data from the Swedish

Popular Abstract in Swedish Denna avhandling handlar om intensiv familjeterapi. Presentationen av arbetet är upplagt på så sätt att jag börjar med en genomgång av forskningsläget för familjeterapeutiskt arbete. Jag presenterar därefter olika familjeterapeutiska skolors bidrag till tankestoffet inom intensiv familjeterapi. Inom denna del finns också presentationer av behandlingsprogram med bredspekThis dissertation consists of four sections. Section 1 deals with a presentation of a model for Intensive Family Therapy (IFT) and of the units practising this model. References to research in the field of Family Therapy as well as to relevant theories are made. A theoretical model for describing the functioning of these units is presented. Measuring instruments were developed on the basis of this