Syvälämpökaivon analysointi lämpöpumppujärjestelmissä

Deep-heat wells in bedrock are a new potential heat source for heat pumps. With a depth up to ten-fold compared to state-of-the-art boreholes, a deep-heat well could extract much more heat from the same area enabling installation of heat pumps in densely populated areas. In this thesis, comprehensive thermal analyses were made to better understand the performance of such systems. For this purpose, a simulation model for deep-heat wells was developed with the COMSOL Multiphysics software. The performance of a deep well is influenced by many geophysical, thermophysical, and engineering factors. For example, a higher thermal conductivity and thermal gradient increases the thermal output of the borehole heat exchanger. There is a strong link between the well performance and inlet temperature of fluid and mass flow rate. The simulations indicate that a 2 km deep well with a coaxial borehole heat exchanger produces 110 kW (55 W/m) at steady state. The yearly heat energy output would be 30-fold com-pared to a traditional borehole. Different operational strategies and well configurations were also analyzed. The deep-heat well can be used for heat storage, e.g. with power-to-heat schemes enabling quite high charging power levels up to 1 MW for shorter periods. Using multiple wells increases the overall performance, but the wells start to interfere each other’s performance with more than four wells with 30 m well distance. The borehole heat exchanger contains some special issues due to its length. To avoid thermal short-circuiting, a vacuum tube type of solution is recommended instead of plastic pipes, which could drop the heat output by even 50%. Setting an optimal flow rate is also important, as the electricity needed for pumping the heat transfer fluid could easily reduce the system COP by up to 10%, or even more in non-optimal systems. The thesis results emphasize careful planning and design of deep-heat systems, in particular in geoengineering and thermal engineering, when moving to practical pilot project. Comprehensive optimization of deep-heat systems would be relevant for future work to establish standard designs for practitioners.Syväkaivolämpö on uusi lupaava lämmönlähde lämpöpumpuille. Se on jopa kymmenen kertaa syvempi kuin perinteiset porareiät, jolloin se pystyy ottamaan huomattavasti enemmän lämpöä samalta pinta-alalta mahdollistaen lämpöpumppujen laajemman käytön kaupunkialueilla. Tässä diplomityössä tutkittiin perusteellisesti syväkaivojen lämpöteknistä toimintaa ja suorituskykyä. Työssä laadittiin simulointimalli syväkaivolle COMSOL Multiphysics -ohjelmiston avulla. Syväkaivon toimintaan vaikuttavat monet geofysikaaliset ja lämpötekniset parametrit ja tekniset ratkaisut. Esimerkiksi korkeampi kallion lämmön johtavuus ja lämpögradientti parantavat syväkaivon lämmön tuotantoa. Virtausnopeus ja sisään menevän nesteen lämpötila vaikuttavat suuresti kaivon suorituskykyyn. Simuloinnit osoittavat, että 2 km syvä koaksiaalinen lämpökaivo voisi tuottaa lämpöä 110 kW (55 W/m) tasapainotilassa. Syväkaivon vuosituotto on tällöin jopa 30-kertainen tavanomaiseen porareikään verrattuna. Työssä tutkittiin myös erilaisia toimintastrategioita. Syväkaivoa voidaan käyttää lämmön varastointiin esimerkiksi ’power-to-heat’-konversion yhteydessä mahdollistaen lyhyillä latausjaksoilla jopa 1 MW lataustehon. Useampia kaivoja käytettäessä suorituskyky paranee, mutta kaivot alkavat vuorovaikuttamaan vahvemmin keskenään, kun niiden määrä kasvaa yli neljän, mikä tiputtaa yhdestä kaivosta saatavan lämmön määrää. Syväkaivoon liittyy erityispiirteitä sen pituudesta johtuen. Termisen oikosulun välttämiseksi on suositeltavaa käyttää tyhjiöputkiratkaisua muoviputkien sijaan, jotka saattavat pudottaa saatavan lämpötehon jopa puoleen. Lämmönsiirtonesteen virtausnopeuden optimaalinen asetus on myös tärkeää, koska pumppaukseen tarvittava sähkö voi helposti pudottaa lämpöpumpun lämpökerrointa 10% tai jopa enemmän, jos virtausnopeus on optimiarvoa paljon korkeampi. Diplomityön johtopäätökset painottavat syväkaivojen huolellista suunnittelua ja erityisesti erilaisten lämpö- ja geoteknisten seikkojen huomioon ottamista, kun edetään käytännön projekteihin. Syväkaivojen kattava optimointi olisi tulevaisuudessa hyödyksi suunnittelukäytäntöjen vakiinnuttamiseksi

Fast time variations of supernova neutrino fluxes and their detectability

In the delayed explosion scenario of core-collapse supernovae (SNe), the accretion phase shows pronounced convective overturns and a low-multipole hydrodynamic instability, the standing accretion shock instability (SASI). These effects imprint detectable fast time variations on the emerging neutrino flux. Among existing detectors, IceCube is best suited to this task, providing an event rate of ~1000 events per ms during the accretion phase for a fiducial SN distance of 10 kpc, comparable to what could be achieved with a megaton water Cherenkov detector. If the SASI activity lasts for several hundred ms, a Fourier component with an amplitude of 1% of the average signal clearly sticks out from the shot noise. We analyze in detail the output of axially symmetric hydrodynamical simulations that predict much larger amplitudes up to frequencies of a few hundred Hz. If these models are roughly representative for realistic SNe, fast time variations of the neutrino signal are easily detectable in IceCube or future megaton-class instruments. We also discuss the information that could be deduced from such a measurement about the physics in the SN core and the explosion mechanism of the SN.Comment: 14 pages, 11 figures. Final version accepted in PRD. Section on astrophysical relevance and several references adde

cphVB: A System for Automated Runtime Optimization and Parallelization of Vectorized Applications

Modern processor architectures, in addition to having still more cores, also require still more consideration to memory-layout in order to run at full capacity. The usefulness of most languages is deprecating as their abstractions, structures or objects are hard to map onto modern processor architectures efficiently. The work in this paper introduces a new abstract machine framework, cphVB, that enables vector oriented high-level programming languages to map onto a broad range of architectures efficiently. The idea is to close the gap between high-level languages and hardware optimized low-level implementations. By translating high-level vector operations into an intermediate vector bytecode, cphVB enables specialized vector engines to efficiently execute the vector operations. The primary success parameters are to maintain a complete abstraction from low-level details and to provide efficient code execution across different, modern, processors. We evaluate the presented design through a setup that targets multi-core CPU architectures. We evaluate the performance of the implementation using Python implementations of well-known algorithms: a jacobi solver, a kNN search, a shallow water simulation and a synthetic stencil simulation. All demonstrate good performance

Digital Tools and Instructional Rules: A study of how digital technologies become rooted in classroom procedures

This paper examines how a classroom culture developsadvanced strategies and procedures for handling complexdigital tools. We report from a vocational Mediaand Communication course at an Upper SecondarySchool in Oslo, Norway. Our analysis reveals how aprocedure called practical assignments has developedhistorically at the school, and how this procedure iscarried out in the classroom. Theoretically, our studyis informed by Activity Theory, which affords us toolsto analyze how social institutions and learning trajectoriesevolve over time, and how longitudinal dimensionsemerge in situ. Our findings show how teachers andlearners create a space for solving context-specific problemsinvolving sophisticated technology. A historicalanalysis is here crucial not only in understanding whydigital technologies are used in specific ways, but alsohow they evolve into classroom conventions

Quality and management in kindergarten - an organizational challenge.

Bacheloroppgave, barnehagelærerutdanning, 2016.Norsk: Denne oppgaven fokuserer på hvordan ledelse basert på blant annet ytre motivasjon og strenge dokumentasjonskrav kan gi implikasjoner for prosesskvaliteten i norske barnehager. Gjennom analyse av teori og forskning i tilknytning til kvalitetsbegrepet, New Public Management, samt Human Resource Management ser den på hvordan sentrale faktorer innenfor ulike organisasjonsteorier har preget, og fortsatt preger barnehagesektoren i dag. Det trekkes også sammenligninger mellom de ulike teoriene for å gi en bredere forståelsesramme rundt oppgavens problemstilling. Med hovedvekt på forskning og litteratur innenfor Human Resource Management gjør oppgaven rede for hvordan ledelse sterkt preget av faktorer innenfor den harde varianten av dette feltet vil gi mindre tid til å utføre, samt lavere motivasjon til gjennomføring av de relasjonelle handlinger som kreves for utøvelse av god prosesskvalitet.English: This bachelor thesis wil focus on how management including external motivation and documentation requirements may provide implications for the process quality in Norwegian kindergartens (age 1-6). Through analysis of theory and research related to quality, New Public Management, and Human Resource Management this thesis looks at how key factors within different organizational theories have characterized, and still have an impact on kindergartens today. It also compare the different theories to provide a larger understanding around the issue of the task. With an emphasis on research and literature in Human Resource Management this thesis explain how management strongly influenced by factors within the hard variant of this field, will give less time to perform, as well as lower motivation for the implementation of the relational acts who is required for the exercise of good process quality

LPS Counter Regulates RNA Expression of Extracellular Proteases and Their Inhibitors in Murine Macrophages

Besides their evident importance in host defense, macrophages have been shown to play a detrimental role in different pathological conditions, including chronic inflammation, atherosclerosis, and cancer. Regardless of the exact situation, macrophage activation and migration are intimately connected to extracellular matrix degradation. This process is accomplished by multiple proteolytic enzymes, including serine proteases and members of the matrix metalloproteinase family. In this study, we have utilized qPCR arrays to simultaneously analyze the temporal expression pattern of a range of genes involved in extracellular matrix metabolism in the mouse derived-macrophage cell line RAW 264.7 following stimulation with LPS. Our results revealed that LPS induces the expression of matrix metalloproteinases while at the same time decreased the expression of matrix metalloproteinase inhibitors. The opposite scenario was found for the genes encoding serine proteases, which were downregulated while their inhibitors were upregulated. In addition, intergenic comparison of the expression levels of related proteases revealed large differences in their basal expression level. These data highlight the complexity of the gene expression regulation implicated in macrophage-dependent matrix degradation and furthermore emphasize the value of qPCR array techniques for the investigation of the complex regulation of the matrix degradome

Karakterer korrelerer ikke med kunnskapsnivå

Formålet med denne studien var å undersøke hvorvidt allmennkunnskap korrelerer med gjennomsnittskarakterer hos elever i tredjeklasse på videregående. En quiz ble gitt til 96 elever på to forskjellige videregående skoler hvor de anonymt fylte ut kjønn, bursdagsmåned, bydel, hvor i søskenflokken de er, samt deres gjennomsnittskarakter. Quizen hadde fem kategorier med ti spørsmål i hver kategori. Resultatene varierte fra tre til 34 riktige svar, med en gjennomsnittskarakter som varierte fra 3,7 til 5,9. De forskjellige gruppene ble videre delt inn i grupper og sammenlignet med korrelasjon, standardavvik og/eller T.Test for å vise om forskjellene var signifikante eller ikke. Resultatet viste en korrelasjonskoeffisient på 0,09 og det betyr at det ikke var en sammenheng mellom karakterer og allmennkunnskap. Det var heller ingen korrelasjon mellom hvilken bydel eleven bodde i, hvilken måned man var født i eller hvor i søskenflokken man er. &nbsp