Solar Photovoltaic Potential on Commercial Buildings in Arctic Latitudes

This thesis desires to study the use of solar resources in a less frequently used location, by exploring the use of a photovoltaic systems on the roof of a warehouse in Tromsø, Norway. The research is gathered using a 15 000 2 warehouse as the location, which has an annual energy consumption of 2,9 GWh. The solar resources at this location are highly dependent on season, with periods of polar nights during winter and midnight sun during summer. With this in mind this study considers solar radiation conditions, area utilization and energy production for three photovoltaic systems to find the optimal system for harvesting energy under the mention constraints. The three systems evaluated consists of horizontal modules, 40° tilted south orientated modules and 40° tilted east-west orientated modules, and their energy production respectively covers 16%, 16% and 25% of the warehouse consumption. Being capable of producing the most energy, system design and an economic analysis is performed for the system with 40° tilted east-west orientated modules, resulting in a break-even price of 0,38 NOK/kWh. The system consists of 3456 modules with a combined power of 1382 kWp and requires an investment cost of 5 961 000 NOK. In the pursuit of relieving stress from the grid and decreasing the washhouse’s electricity cost, this study also the investigates the idea of utilizing otherwise unused roofs on neighbour buildings for solar energy production and transmit the energy to the warehouse with inter-building cables. Two building were considered, one closer but limited in size, and one larger in size but further away. Results prove the short inter-building distance to be most profitable when electricity prices are below 0,9 NOK/kWh, due to lower investment costs. For prices above 0,9 NOK/kWh, the extra cost of the longer distance would be more profitable due to the possibility of a larger production area

Strategies of authentication in Japanese experimental music

I denne oppgaven har jeg valgt å ta for meg på hvilken måte japanske eksperimentelle musikere forholder seg til krav om autensitet. Det finnes ingen klar definisjon på autensitet, og inneholdet i ordet kan i stor grad variere utifra hvem som bruker det og i hvilken situasjon det brukes. Allikevel finnes det enkelte definisjoner som har hatt større gjennomslagskraft enn andre. Kort oppsummert blir det som av en eller annen grunn oppfattes som 'ekte' og 'ikke kopiert' også ansett som autentisk. I en musikksammenheng kan det brukes om ulike former for folkemusikk, fordi folkemusikk representerer den ‘ekte’ kulturen den oppsto i. Dette kalles ofte kulturell autensitet. Personlig autensitet oppnås i det en musiker eller gruppe musikere fremfører musikk med ett personlig budskap. Kommersiell pop-musikk oppfattes derfor av mange som lite autentisk fordi dens funksjon i stor grad er å generere penger til plateselskaper. Fordi dette er en av hovedprioriteringene i kommersiell musikk, krever det at musikken følger en rekker konvensjonelle regler og strukturer. På den annen side finnes eksperimentell musikk. Eksperimentell musikk oppfattes ofte som mer autentisk en kommersiell musikk fordi den først og fremst krever individualisme, kreativitet og originalitet. I Japan finnes det i dag et innflytelsesrikt eksperimentelt musikkmiljø, som i økende grad har fått oppmerksomhet fra tilsvarende miljøer i vesten. Mange japanske musikere har fått oppmerksomhet i vesten for sin utradisjonelle og kreative tilnærming musikk. Samtidig finnes det en rekke stereotypier og fordommer om japanere som i sin ytterste konsekvens ville tilsi at et slikt miljø ikke kan oppstå i det japanske samfunnet. Både i vesten og i Japan er det en utbredt oppfatning at japanere er gruppeorienterte i motsetning til individualistene i vesten. Japanere er teknisk flinke men har vanskelig for å uttrykke sin egen personlighet. En av de kanskje mest utbredte fordommene er at japanere kopierer vesten mens de selv er uoriginale og lite kreative. Flere av disse antatte karakteristikkene ville gjøre det umulig for japansk musikk å kunne oppfattes som autentisk. I denne oppgaven vil jeg forsøke å vise hvilke strategier Japanske musikere har tatt i bruk for å imøtegå dette problemet

Fitting multiple small-angle scattering datasets simultaneously: on the optimal use of priors and weights

Small-angle X-ray and neutron scattering (SAXS and SANS) are powerful techniques for elucidating the structure of diverse particles and materials. This study address the challenge of effectively combining SAXS and SANS data for accurate structural parameter determination. Surprisingly, our results demonstrate that equally weighting all data points leads to the most accurate parameter estimation, even when SAXS data significantly outnumber SANS data. We compared this approach with weighting schemes normalized by the number of points and by the derived information content. Furthermore, we assessed the impact of prior knowledge by incorporating Gaussian priors for model parameters. Our findings indicate that Gaussian priors improve the accuracy of refined parameter values compared to uniform priors. When using a minimum and a maximum values for model parameters, which is common practice, uniform priors are implicitely applied. Finally, we show that utilizing information content aids in determining the degrees of freedom, enabling accurate calculation of the goodness of fit. In conclusion, this research provides valuable insights into the optimal combination of SAXS and SANS data, emphasizing the importance of weighting schemes and prior knowledge for enhanced accuracy in structural parameter determination

Overestimation of closed-chamber soil CO2 effluxes at low atmospheric turbulence

Soil respiration (Rs) is an important component of ecosystem carbon balance, and accurate quantification of the diurnal and seasonal variation of Rs is crucial for a correct interpretation of the response of Rs to biotic and abiotic factors, as well as for estimating annual soil CO2 efflux rates. In this study, we measured Rs hourly for 1 year by automated closed chambers in a temperate Danish beech forest. The data showed a clear diurnal pattern of Rs across all seasons with higher rates during night-time than during daytime. However, further analysis showed a clear negative relationship between flux rates and friction velocity (u∗) above the canopy, suggesting that Rs was overestimated at low atmospheric turbulence throughout the year due to non-steady-state conditions during measurements. Filtering out data at low u∗ values removed or even inverted the observed diurnal pattern, such that the highest effluxes were now observed during daytime, and also led to a substantial decrease in the estimated annual soil CO2 efflux. By installing fans to produce continuous turbulent mixing of air around the soil chambers, we tested the hypothesis that overestimation of soil CO2 effluxes during low u∗ can be eliminated if proper mixing of air is ensured, and indeed the use of fans removed the overestimation of Rs rates during low u∗. Artificial turbulent air mixing may thus provide a method to overcome the problems of using closed-chamber gas-exchange measurement techniques during naturally occurring low atmospheric turbulence conditions. Other possible effects from using fans during soil CO2 efflux measurements are discussed. In conclusion, periods with low atmospheric turbulence may provide a significant source of error in Rs rates estimated by the use of closed-chamber techniques and erroneous data must be filtered out to obtain unbiased diurnal patterns, accurate relationships to biotic and abiotic factors, and before estimating Rs fluxes over longer timescales