<p>We live in a world of becoming. The future is not given, but forms continuously in dynamic processes where path dependence plays a major role. There are many different possible futures. What we actually end up with is determined in part by chance and in part by the decisions we make. To make sound decisions we require models that are flexible enough to identify opportunities and to help us choose options that lead to advantageous alternatives. This way of thinking differs from traditional cost-benefit analysis that employs net present value calculations to choose on purely economic grounds, without regard to future consequences.</p><p>Time and dynamic behaviour introduce a separate perspective. There is a focus on change, and decisions acquire windows of opportunity: the right decision at the right time may lead to substantial change, while it will have little effect if too early or too late. Modelling needs to reflect this dynamic behaviour. It is the perspective of time and dynamics that leads to a focus on sustainability, and thereby the role hydrogen might play in a future energy system. The present work develops a particular understanding relevant to energy infrastructures.</p><p>Central elements of this understanding are:</p><p>- Competition</p><p>- Market preference and choice beyond costs</p><p>- Bounded rationality</p><p>- Uncertainty and risk</p><p>- Irreversibility</p><p>- Increasing returns</p><p>- Path dependence</p><p>- Feedback</p><p>- Delay</p><p>- Nonlinear behaviour</p><p>Change towards a “hydrogen economy” will involve far-reaching change away from our existing energy infrastructure. This infrastructure is viewed as a dynamic set of interacting technologies (value sequences) that provide services to end-users and uphold the required supply of energy for this, all the way from primary energy sources. The individual technologies also develop with time.</p><p>Building on this understanding and analysis, an analytical tool has emerged: the Energy Infrastructure Competition (EICOMP) model. In the model each technology is characterised by a capacity, an ordered-, and an actually delivered volume of energy services. It is further characterised through physical description with parameters like efficiency, time required for extending capacity and improvement by learning. Finally, each technology has an attractiveness, composed of costs, quality and availability, that determines the outcome of competition.</p><p>Change away from our present energy infrastructure into a sustainable one based on renewable energy sources, will entail substantial change in most aspects of technology, organisation and ownership. Central results from the overall work are:</p><p>- <i>Change is dynamic and deeply influenced through situations with reinforcing feedback and path dependence. Due to this, there is a need for long-term perspectives in today's decision making: decisions have windows of opportunity and need to be made at the proper time.</i></p><p>- <i>Strategies aimed at achieving change should team up with reinforcing feedback and avoid overwhelming balancing feedback that counteracts change.</i></p><p>- <i>The EICOMP model is now available as a tool for furthe analysis of our existing energy infrastructure and its dynamic development into possible, alternative energy futures. As the model is intended for practical guidance in decisions, a central practical aim has been to allow it to be used close to where decisions are actually made; i.e. decentralised and locally in firms and in public institutions. In this respect much effort has been made in an attempt to make it transparent and easy to communicate.</i></p><p>- <i>The EICOMP model may be used to analyse situations of reinforcing feedback throughout the alternative energy infrastructures that we may come to have in the future.</i></p>

This dissertation deals with (1) experimental measurements on petrophysical reservoir engineering and morphological properties of Ekofisk chalk, (2) numerical simulation of core flood experiments to analyze and improve relative permeability data, (3) stochastic reconstruction of chalk samples from limited morphological information, (4) extraction of pore space parameters from the reconstructed samples, development of network model using pore space information, and computation of petrophysical and reservoir engineering properties from network model, and (5) development of 2D and 3D idealized fractured reservoir models and verification of the applicability of several widely used conventional upscaling techniques in fractured reservoir simulation. Experiments have been conducted on eight Ekofisk chalk samples and porosity, absolute permeability, formation factor, and oil-water relative permeability, capillary pressure and resistivity index are measured at laboratory conditions. Mercury porosimetry data and backscatter scanning electron microscope images have also been acquired for the samples. A numerical simulation technique involving history matching of the production profits is employed to improve the relative permeability curves and to analyze hysteresis of the Ekofisk chalk sample. The technique was found to be a powerful tool to supplement the uncertainties in experimental measurements. Porosity and correlation statistics obtained from backscatter scanning electron microscope image are used to reconstruct microstructures of chalk and particulate media. The reconstruction technique involves a simulated annealing algorithm, which can be constrained by an arbitrary number of morphological parameters. This flexibility of the algorithm is exploited to successfully reconstruct particulate media and chalk samples using more that one correlation function. A technique based on conditional simulated annealing has been introduced for exact reproduction of vuggy porosity in chalk in the form of foraminifer shells. A hybrid reconstruction technique that initialized the simulated annealing reconstruction with input generated using the Gaussian random field model has also been introduced. The technique was found to accelerate significantly the rate of convergence of the simulated annealing method. This finding is important because the main advantage of the simulated annealing method, namely its ability to impose a variety of reconstruction constraints, is usually compromised by its very slow rate of convergence. Absolutely permeability, formation factor and mercury-air capillary pressure are computed from simple network models. The input parameters for the network models were extracted from a reconstructed chalk sample. The computed permeability, formation factor and mercury-air capillary pressure correspond well with the experimental data. The predictive power of a network model for chalk is further extended through incorporating important pore-level displacement phenomena and realistic description of pore space geometry and topology. Limited results show that the model may be used to compute absolute and relative permeabilities, capillary pressure, formation factor, resistivity index and saturation exponent. The above findings suggest that the network modeling technique may be used for prediction of petrophysical and reservoir engineering properties of chalk. Further works are necessary and an outline is given with considerable details. Two 2D, one 3D and a dual-porosity fractured reservoir models have been developed and an imbibition process involving water displacing oil is simulated at various injection rates and with different oil-to-water viscosity ratios using four widely used conventional upscaling techniques. The upscaling techniques are the Kyte &amp; Berry, Pore Volume Weighted, Weighed Relative Permeability, and Stone. The results suggest that the upscaling of fractured reservoirs may be possible using the conventional techniques. Kyte &amp; Berry technique was found to be the most effective in all situations. However, further investigations are necessary using realistic description of fracture length, orientation, connectivity, aperture, spacing, etc. / Paper 3,4 and 5 reprinted with kind persmission of Elsevier Science, Science Direct.

We live in a world of becoming. The future is not given, but forms continuously in dynamic processes where path dependence plays a major role. There are many different possible futures. What we actually end up with is determined in part by chance and in part by the decisions we make. To make sound decisions we require models that are flexible enough to identify opportunities and to help us choose options that lead to advantageous alternatives. This way of thinking differs from traditional cost-benefit analysis that employs net present value calculations to choose on purely economic grounds, without regard to future consequences. Time and dynamic behaviour introduce a separate perspective. There is a focus on change, and decisions acquire windows of opportunity: the right decision at the right time may lead to substantial change, while it will have little effect if too early or too late. Modelling needs to reflect this dynamic behaviour. It is the perspective of time and dynamics that leads to a focus on sustainability, and thereby the role hydrogen might play in a future energy system. The present work develops a particular understanding relevant to energy infrastructures. Central elements of this understanding are: - Competition - Market preference and choice beyond costs - Bounded rationality - Uncertainty and risk - Irreversibility - Increasing returns - Path dependence - Feedback - Delay - Nonlinear behaviour Change towards a “hydrogen economy” will involve far-reaching change away from our existing energy infrastructure. This infrastructure is viewed as a dynamic set of interacting technologies (value sequences) that provide services to end-users and uphold the required supply of energy for this, all the way from primary energy sources. The individual technologies also develop with time. Building on this understanding and analysis, an analytical tool has emerged: the Energy Infrastructure Competition (EICOMP) model. In the model each technology is characterised by a capacity, an ordered-, and an actually delivered volume of energy services. It is further characterised through physical description with parameters like efficiency, time required for extending capacity and improvement by learning. Finally, each technology has an attractiveness, composed of costs, quality and availability, that determines the outcome of competition. Change away from our present energy infrastructure into a sustainable one based on renewable energy sources, will entail substantial change in most aspects of technology, organisation and ownership. Central results from the overall work are: - Change is dynamic and deeply influenced through situations with reinforcing feedback and path dependence. Due to this, there is a need for long-term perspectives in today's decision making: decisions have windows of opportunity and need to be made at the proper time. - Strategies aimed at achieving change should team up with reinforcing feedback and avoid overwhelming balancing feedback that counteracts change. - The EICOMP model is now available as a tool for furthe analysis of our existing energy infrastructure and its dynamic development into possible, alternative energy futures. As the model is intended for practical guidance in decisions, a central practical aim has been to allow it to be used close to where decisions are actually made; i.e. decentralised and locally in firms and in public institutions. In this respect much effort has been made in an attempt to make it transparent and easy to communicate. - The EICOMP model may be used to analyse situations of reinforcing feedback throughout the alternative energy infrastructures that we may come to have in the future.

I de senere årene har det blitt mer fokus på å bruke dyr og gården i arbeid med mennesker. Dette kan sees i forskning og evalueringsrapporter, og spesielt med mennesker med psykiske lidelser, eldre med demens, gårdsbarnehager og skoler som har gårdsaktiviteter. Det er derimot lite forskning på barn og unge som er plassert i tiltak på gårder via barnevernet. Det å kombinere dyr og gårdsarbeid sammen med mennesker har fellesbegrepet Inn på tunet (IPT). Forskningen på IPT hevder generelt at mennesker som har ulike vanskeligheter som psykiske lidelser, demens eller lærevansker kan ha stort utbytte av å ha nærkontakt med dyr og å gjøre praktiske oppgaver på en gård. Dette kan blant annet føre til positive opplevelser, bedre selvtillit og mestring. I forskningen på IPT er det som regel voksne, eller tilbydere av IPT- tjenester som uttaler seg på området, mens det er lite av der hvor barn og unge får sin stemme. Denne oppgaven baserer sin undersøkelse på et kvalitativt semistrukturert forskningsintervju og deltagende observasjon. Deltagerne var 6 ungdommer i alder 16-20 år, som har avlastningstiltak på Buan gård. Det ble utarbeidet en intervjuguide for intervjuene, og lagt til rette for deltagende observasjoner som ble gjort på to helger ungdommene var på gården. Oppgaven innehar et fenomenologisk og hermeneutisk perspektiv for å få tak i ungdommenes opplevde livsverden på gården. Dette gjør at oppgaven har fokus på ungdommenes perspektiv, og søker å få tak i deres meninger og opplevelser av å være i et avlastningstiltak på en gård. Oppgaven har følgende problemstilling: Hvordan opplever ungdommer som er plassert i avlastningstiltak av barnevernet å være på en gård, og hvordan kan disse opplevelsene bidra til mestring? Resultatene viser at de faktorene ungdommene legger til grunn for trivsel på avlastningsgården er det sosiale, opplevelser, dyr, rom for læring og utvikling, samt følelsen av trygghet. Ungdommene gir uttrykk for å trives på gården, og fremhever disse faktorene som spesielt viktig for trivsel. Videre kan disse faktorene for trivsel bidra til å utvikle motstandskraft hos ungdommene ved mestringens vilkår, nemlig dyaden, familien og sosialt nettverk. Faktorene ble satt inn i denne sammenhengen, og det har blitt vist at gården i sin helhet kan bidra til at ungdommene kan ha utviklet motstandskraft og resiliens på gården. / The use of animals and the farmyard environment for treatment of human beings has become increasingly popular during recent years. Evidence of this is apparent in research journals and reports, in particular within research on psychological problems, elderly with dementia and work with kindergartens and schools. A somewhat less explored area is the effect of this way of treatment on children and adolescents currently in contact with child protection. Using animals and farm work in treatment or therapy of people has been termed as green care (in Norwegian: “grønn omsorg” or “Inn på tunet” (IPT). Research within this area indicates that people suffering from psychological problems, dementia or learning disabilities can greatly benefit from close contact with animals and experiencing life on a farm. Benefits include positive experiences, improved self confidence and a feeling of accomplishment and coping. Previous studies have focused on interviewing adults going through this treatment, while the children's opinions are seldom heard. This master thesis is based on qualitative, semi-structured interviews and participating observation. The informants were 6 children in age between 16 and 20, who were visiting a farm to relieve their parents or themselves. In this case the farm is Buan farm. An interview guide was devised and participating observation was carried out during two weekend visits to the farm. The thesis focuses on the adolescents opinions and experiences from visiting the farm. The following research question has been chosen for this work: How do teens in contact with child protection experience life on a farm, and how can these experiences contribute to coping? The results of my study show that the most important factors for the adolescents are the social interactions, the positive experiences, the animals, the feeling of accomplishment and learning as well as a feeling of safety and belonging. The adolescents listed these factors as reasons for enjoying their visits to the farm. I show how these factors can contribute to developing a general resilience in the adolescents through coping in dyad, family and a social network. I argue strongly that visiting the farm helps to improve the adolescents everyday coping and resilience.

The thesis investigates hot carrier relaxation and carrier recombination mechanism of a InN thin film grown on LAO(LiAlO2) substrate with a ultrafast time-resolved photoluminescence apparatus. Carriers were excited with laser pulses of energy 1.5 eV and of pulsewidth 150 fs from a Ti:sapphire laser. The photoexcited carriers relax excessive energy mostly within 10 ps thorough carrier-LO-phonon interaction. The effective carrier-LO-phonon emission times were estimated 197 to 58 fs in the temperature range from 250 to 35 K. The Shockley-Read-Hall coefficient was found around 0.8 ns-1. The Auger recombination was trivial at 35 K and become significant at 250 K. The fitted radiative recombination was much smaller than the theoretical estimate. Both effective carrier-LO-phonon scattering times and the radiative and nonradiative decay rates of the studied m-plane InN were found to be smaller than those of c-plane InN in other reports.

We studied terahertz radiation from InN in our paper. We set up " Terahertz Time-Domain Spectroscopy system" and investigate Terahertz emission from InN. We take our sample(InN) in the rotation stage and we rotate different angle to detect the THz intensity data and wave shape and also the mechanisms of THz wave emitted. We research the influence from different background carrier density, band gap, mobility and structure(Zb-InN, W-InN) of InN to produce Terahertz radiation. Finally, we dicuss the THz amplitude and shape influenced from the internal surface field effect, Photo Dember effect, stacking fault, c-plane and m-plane from InN.

Abstract We have extended the spectral range of the current PL-upconversion apparatus to be operated in infrared. Using the IRPL-upconversion¡Awe study the behavior of carrier cooling of InN film and the relationship between the spacer and lifetime in InAs/GaAs stacked QDs . We excited InN film of the band gap of 0.74eV with ultrafast Ti:sapphire laser of the wavelength 404nm. We found the phonon emission time by hot carriers of InN is 14fs. The hot carriers release their excess energy to the lattice of 35K with a timescale of 100ps. We observed in InAs/GaAs QDs that the shorter life time for samples with thin spacer is due to tunneling effect.

This thesis will talk about the difference between c-plane and m-plane GaN. We use C-V measurement and try to find the difference from C-V result. We use atomic layer deposit (ALD) to deposit Al2O3 no n-Si (111), p-Si (111), c-GaN, m-GaN, c-InN and m-InN for making MOS structure. And use 100 kHz to measure high frequency C-V and charge-voltage method to measure quasi-static capacitance and leakage current. The process and how the instrument work will present in article. In Si (111) case, the flat-band voltage is far away from ideal value. This tells us charge in oxide. Result of quasi-static method shows interface state density is between 1011 cm-2¡DeV-1 to 1012 cm-2¡DeV-1. From Ref. 13, SiO2-Si system with 1011 cm-2 interface trap charge density for Si (111). We compare C-V carrier concentration with Hall carrier concentration and find some difference. We put C-V result of experiment and simulated with COX and Hall carrier concentration we measured. In GaN case, here is deep depletion in C-V result. And quasi-static result also shows deep depletion of GaN. This phenomenon means generate time of hole of n-type GaN is very long. And we use light to excite electron and hole and measure C-V for average surface density of state. The density of stay of Al2O3/m-GaN and Al2O3/c-GaN system is similar. Only appearance difference between Al2O3/m-GaN and Al2O3/c-GaN is position of flat-ban voltage. flat-ban voltage of c-GaN is more negative than m-GaN. For InN, we see ¡§the middle is lower than edge¡¨ curve. Recently, few group present complete C-V curve of InN. We can not sure whether we can use typical way to analyze this data.

The purpose of this thesis is to find out carrier concentration in nitride semiconductors by micro Raman measurements. We focus on the Raman measurements of two different III-nitride semiconductors doped with Si. First series is narrow band gap InN films with varying carrier concentration (ne). The highest (ne) in this series is 1.9 X 1019 cm-3. The second series is wide band gap GaN films, with highest (ne) of 8.0 X 1019 cm-3.From the room temperature Ramam measurements ,it is observed that the L- LOPCM (lower branch of longitudinal-optical phonon-plasmon coupled modes) depends on the carrier concentration. We focus the further analysis of this result and try to extract the carrier concentration and compare with electrical measurements.

This dissertation investigates the growth of high quality GaN and InN thin films by plasma assisted molecular beam epitaxy (PAMBE). It also explores the growth of self-seeded GaN branching nanowires and p-type doping of InN, two topics of particular interest at present. The growth of high quality III-Nitride semiconductor thin films have been shown to be dependent on the group-III (metal) to nitrogen ratio. A metal-rich growth environment enhances the diffusion of the group-III adatoms through the formation of a group-III adlayer. By using a metal-rich growth environment, determined by growth rate studies using laser reflection interferometry or RHEED analysis of the surface, both GaN and InN films have been grown with a smooth surface morphology. Additionally the smooth surface morphology has beneficial effects on the electrical and optical properties of both materials. However, with the growth using a metal-rich environment, group-III droplets are present on all film surfaces, which can be an issue for device fabrication, as they produce facets in the crystal structure due to enhanced growth rates. MBE growth of GaN nanowires via the vapour liquid solid (VLS) and vapour solid (VS) growth techniques have so far been based on the N-rich growth regime. However, we have shown that the Ga-rich growth regime can be used to grow self-seeded one dimensional and hierarchical GaN nanowires. 7 µm long hierarchical GaN nanowires with at least three branches were grown and shown to have a high crystalline quality. The suggested growth mechanism is a self-seeding VLS process driven by liquid phase epitaxy at the nanoscale, while the branching growth was nucleated due to the Ga-rich growth regime by excess Ga droplets forming on the trunk during growth. The growth of vertical GaN nanowires has also been achieved using the same self-seeding process and the critical parameter seems to be the Ga to N ratio. Also, the growth rate of the Ga-rich grown GaN nanowires can supersede the growth rates reported from N-rich grown GaN nanowires by at least a factor of two. The fabrication of vertical and planar GaN nanowire devices has been demonstrated in this study. Two point and three point contacts were fabricated to the branching GaN nanowires in the planar direction with resistive measurements ranging from 200 - 900 kΩ, similar to chemical vapour deposition and MBE grown GaN nanowires. The nonlinear current-voltage characteristics from the three point contacts may lead to unique nano-devices. The planar nanowires have also shown to have potential as UV detectors. Schottky diodes were fabricated on the vertical nanowires, with values for the barrier heights consistent with bulk diodes. Mg and Zn doping studies of InN were also performed. Both InN:Mg and InN:Zn have strong photoluminescence only at low doping concentrations. However, the InN:Mg films have reduced mobilities with increased Mg content, whereas the mobility determined from the InN:Zn films is independent of Zn. When the InN:Zn film quality was improved by growing under the In-rich growth regime, electrochemical capacitance-voltage results suggest n{type conductivity, and strong photoluminescence was obtained from all of the films with four features seen at 0.719 eV, 0.668 eV, 0.602 eV and 0.547 eV. The features at 0.719 eV and 0.668 eV are possibly due to a near band edge to valence band or shallow acceptor transition, while the 0.547 eV has an activation energy of 60 meV suggesting a deep level acceptor.