Filtyp
Sierra Leone is a small country with rich mineral resources such as diamonds, bauxite, gold and iron ore. Other resources include fishing, forestry and fertile agricultural land, which enable people to farm without any sophisticated methods of mechanization. Nevertheless, with all its wealth in resources, the country is relatively poor and is one of the least developed countries in the Sub-Saharan
The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines. A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from
Diesel engine developers are facing major challenges when meeting future demands on NOx and particulate emissions. The exhausts after treatment systems are rapidly improving and the technologies available in a few years will be capable of cutting emission levels close to the demanded levels. However, in order to reach the low emissions required in a long-lasting, cost effective way, the potential
The effect of duration of ischaemia on final infarct size is well established in animal studies, but not fully evaluated in humans. Delayed contrast-enhanced magnetic resonance imaging (DE-MRI) can be used to distinguish between viable and non-viable myocardium and thus to quantify infarct size. We therefore used DE-MRI to investigate how duration of ischaemia affects final infarct size normalized
This thesis deals with models of flat plate collectors, transparent insulation and efficiency factors. An equation for the energy output from a glazed flat plate collector is derived by modelling the collector efficiency factor, F´ as the sum of a constant and a temperature dependent part. An alternative way of testing a flat plate collector, based on this model, is suggested. A complete set of a
The performance of cyclones used in occupational hygiene for sampling respirable dust was studied. Test methods for experimental determination of cyclone penetration have been designed and validated. The penetration curve for a sampling cyclone presently used in Europe was measured. The sampler's performance relative to three sampling conventions for respirable dust was determined. The cyclone was
With the increased sophistication of medical implants, there is a growing need for flexible high-speed communication with the implant from outside the body. Today the communication is done by an inductive link between the implant and an external coil at a low carrier frequency. Extended range and communication speed are possible to achieve by increasing the carrier frequency and the bandwidth. One
This thesis is concerned with the propagation of transient electromagnetic waves in nonlinear media. It consists of a General Introduction and five scientific papers. The General Introduction gives a broad overview of nonlinear electromagnetic phenomena. The emphasis is on the representation of the constitutive functional modeling the material's response to electromagnetic excitation, and the met
This thesis has the main focus on ways to improve the blood perfusion estimate, as obtained from a continuous wave Doppler system. Earlier studies have shown large temporal variations in the detected perfusion estimate, due to speckle. Here, a theoretical model to predict frequency dependent characteristics of speckle in continuous wave ultrasound is presented. The model predicts the frequency shi
The neutrophil constitutes the first line of defence against invading organisms and its primary function is to recognize, phagocytose and kill intruding microorganisms. In this thesis, the membrane traffic in neutrophils and neutrophil-like cells was studied. Non-opsonised S. pyogenes bacteria was shown to induce a rapid and localised pinosome formation in neutrophils. The pinocytosis was not an i
FASTING DURING THE holy month of Ramadan is both a joy and a jihad for the Islamic community in Java, and it is arguably the most highly esteemed Muslim ritual in Indonesia (and beyond). To be given the opportunity to abstain from food, drink and sexual relations from the early morning hours until sunset during an entire month in a tropical climate - only to fill the nights with additional and sup
This thesis deals with Maya religion and history. The Books of Chilam Balam is the collective title of a body of texts ascribed to the Jaguar Prophet. They are written in the Yucatec Maya language, and tell the reader about Yucatec Maya cosmology, rituals, prophecies, calendars, medicine and they are as well considered as Yucatec Maya emic historiography. These manuscripts are considered enigmatic
One of the noticeable trends in recent years is that products have received increasing attention in environmental policy. The focus on products and their life cycle impacts is often referred to as ?life cycle thinking?. This implies a shift away from the traditional focus on production processes and the environmental impacts of point-source pollution, towards a stronger focus on emissions from the
The mean by which a gas turbine combustor is cooled is of major importance for the efficiency and emission performance of the machine. The trends of increasing top cycle temperature and leaner combustion have also been accompanied by a need of efficient use of the cooling air. Traditional cooling schemes such as film cooling are associated with high coolant flow rates and unacceptable emission lev
Long-range transboundary air pollution generates pressing environmental problems such as the acidification of lakes and soils, forest decline and loss of biodiversity as well as threats to human health across Europe. The overall aim of this study is to explore the role of scientific expertise in environmental diplomacy by analyzing recent international agreements in the transboundary air pollution
In this thesis spectroscopic techniques have been used in the fields of analytical chemistry, environmental and medical applications. In analytical chemistry, laser induced fluorescence was used to image the separation of substances during capillary electrophoresis. Here, an optical fibre imaging technique facilitated a higher sensitivity compared with a lens imaging technique. The motion of the s
A feasibility study of reliability theory as a tool for the assessment of present safety and residual service life of damaged concrete structures has been performed in order to find a transparent methodology for the assessment procedure. It is concluded that the current guidelines are open to interpretation and that the variation in the results obtained regarding the structural safety is too grea
This dissertation explore young peoples will to become artists. A group of artstudents have been interviewed and severel questions are raised. How do the students perceive their artistry and their role as artists? In what way is artistic creation meaningful to them? What does the relationship between the individual project of becoming an artist and their societal participation look like? As artist
This thesis considers static and dynamic team decision problems in both stochastic and deterministic settings. The team problem is a cooperative game, where a number of players make up a team that tries to optimize a given cost induced by the uncertainty of nature. The uncertainty is modeled as either stochastic, which gives the stochastic team problem, or modelled as deterministic where the team
The purpose of this thesis is to develop an increased understanding of strategic alliance processes. A specific aim has been to explore the trust processes involved, and to better understand the dynamics of the strategic alliance processes. The study includes socio-cultural elements and captures both the manager´s and the employee´s perspectives in everyday life. The theoretical discussions were b
