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Stockholm is one of the fastest growing cities in the world. Its population is growing every day and the housing needs are becoming higher. Despite the growth and the need for more houses only a few new housing units are being built every year. Critics argue that if the building rate stays as it is today the development of the city will be very limited since there is no capacity for the city to embrace new incomers. The decision makers in the municipality of Stockholm are planning for large investments in housing units for the coming years up until 2030. There are plans of building approximately 140 000 new apartments to mend the ascending need for new houses. Farsta County is part of Stockholm and lies a few kilometers to the south of the city center. Today the county contains roughly 5 000 housing units. It also contains enormous office facilities rented by the Swedish Telecom company TeliaSonera. These facilities are the current TeliaSonera headquarters, but due to the aging nature of the facilities the company has decided to move out. It is known among market experts that Farsta does not possess the most attractive office location. Thus when TeliaSonera leaves the premises there is potential risk that they will be vacant for quite a long time. And in such situation the opportunity comes to exploit the land in different use than its original. The high need of housing combined with the high office vacancy rate of the county generate the idea of using the land for housing purposes. One can either use the already existing buildings and convert them into apartments and then complete the rest of the land with new buildings, which is a more sustainable alternative. Or one can demolish the existing stock and build a completely new compound. Feasibility and social studies have been carried out in this paper to determine which alternative is the most suitable in the current situation. Out of social point of view the alternative where a completely new compound is produced is more beneficial than the alternative with the conversion and completion. This is due to the higher standard the new apartments will have compared to the other alternative plus, and according to the study, the higher number of flats obtained. It will also be more beneficial economically in the future due to the reduced costs of maintenance. Regardless of which alternative to be chosen the project is going to be costly and it is therefore important to organize it well by finding the financiers and studying all the legal and economic aspects before starting off with it. This project is estimated to produce over 2 500 apartments, a number that says much about the size of the project. / Stockholm är en av världens snabbast växande städer. Dess befolkning ökar för varje dag och behovet av nya bostäder växer. Trots stadens utveckling och det växande bostadsbehovet byggs det enbart ett fåtal nya bostäder årligen. Om det fortsätter att byggas så lite som det görs idag kommer stadens utveckling att hämmas rejält då det inte finns möjlighet för nyinflyttade att bo i staden. Stockholms stad planerar för stora investeringar i bostadssektorn i de kommande åren och fram till år 2030. Avsikten är att bygga färdigt runt 140 000 nya lägenheter fram till 2030 för att minska det växande bostadsbehovet. Farsta är en stadsdel som är belägen ca 10 kilometer söder om Stockholms stadskärna. Idag finns det cirka 5 000 bostäder i stadsdelen. I Farsta finns också TeliaSoneras huvudkontor som består av ett stort kontorsområde. TeliaSonera har beslutat att flytta från Farsta år 2016. Det är känt bland marknads experter att Farsta inte är attraktivt för kontorsverksamhet. När TeliaSonera flyttar ut finns det därför stor risk att lokalerna står vakanta en längre period utan att hyras. Därför är det lämpligt att tänka på alternativa användningar för området. Det växande bostadsbehovet kombinerat med områdets höga vakansgrad på kontor skapar iden om att omvandla området till bostäder. Då finns det sätt att tillgå. Antingen konverteras det gamla beståndet till lägenheter och kompletteras med nya hus för att uppnå önskad täthet för marken, vilket är ett grönare alternativ. Eller rivs allt gammalt och nytt byggs istället. Ekonomiska och sociala faktorer vägs in för att avgöra vilket alternativ är mer passande för dagens behov. Utav samhälleliga anledningar tycks alternativet med totalomvandling (där det gamla beståndet rivs ner) vara mer fördelaktigt jämfört med konverteringsalternativet. Det är på grund av att totalomvandlingen skapar fler lägenheter samt att de nyproducerade lägenheterna har högre standard. I längden kommer detta alternativ att också vara mer ekonomiskt fördelaktig då det har mindre drift- och underhållskostnader. Oavsett vilket alternativ som föredras innebär ett sådant projekt stora kostnader. Därför är det viktigt att redan i ett tidigt skede organisera projektet genom att hitta lämpliga investerare samt att studera de juridiska och ekonomiska aspekterna. Detta projekt beräknas producera drygt 2 500 lägenheter, något som talar om storleken av projektet.

Neutron irradiated copper-boron alloys are employed to study the mutual interaction between metallic crystalline lattices and inert gases. Inert gases precipitate to form gas bubbles and their growth induces dilation of the matrix. This dilation, technically designated as swelling, affects the structural integrity of nuclear fuels during their service. The estimated enthalpy of solution of helium in copper is 5.5 eV/atom. As a Consequence, its solubility in the copper matrix is extremely poor and it cannot enter a copper based matrix via any thermo-chemical route. Hence, recourse to a nuclear reaction is taken to impregnate copper with helium. Helium is produced in situ through neutron irradiation in copper-boron alloys as a result of (n, alpha) nuclear reaction between boron atoms and neutrons. The characteristic feature of the growth of helium gas bubbles driven by isothermal annealing of the metallic matrix is that their rate of growth is highly sensitive to the distance of the bubbles from the external surface of the specimen. The growth of gas bubbles as a function of time and temperature is modulated by the flow of vacancies from the free surface of the specimen. A theory for the surface induced growth of helium gas bubbles in the neutron irradiated copper-boron alloys is presented here.

The rates of dissolution of heavy crude oil in liquid solvents and rates of desorption of solvents from oil have been measured. The crude oil used is a non-volatile heavy oil of 4253 mPa.s viscosity at room temperature. The solvents used are hexane, heptane and toluene. When the oil (black) is contacted with a solvent (transparent) an interface is seen which moves with time and takes a very long time to become fuzzy. The rate of movementof the front is measured. The dissolution experiments give very consistent results, but there are two parameters involved, Do, the diffusivity at infinite dilution and alpha which determines the concentration dependence. As a result it is necessary to do desorption experiments to be able to calculate both constants from the rate of movement of the front data. However, desorption experiments could not be performed under conditions of low concentrations suitable for the present case because of the very viscous nature of the oil. As a result, although the desorption experiments also showed good results, they could not be used to obtain good values of the parameters. When Stokes-Einstein equation was used to calculate Do, excellent results were obtained with alpha ~ 10 for the dissolution experiments and good deal smaller for the desorption experiments. That result is used to conclude that the above form for concentration dependent diffusivity is correct and concentration dependence is very high at low solvent concentrations explaining the sharp interfaces during dissolution.Other evidences have also been offered.

We propose an original analog method to perform instantaneous and quantitative spectral analysis of microwave signals. An ensemble of nitrogen-vacancy (NV) centers held in a diamond plate is pumped by a 532 nm laser. Its photoluminescence is imaged through an optical microscope and monitored by a digital camera. An incoming microwave signal is converted into a microwave field in the area of the NV centers by a loop shaped antenna. The resonances induced by the magnetic component of that field are detected through a decrease of the NV centers photoluminescence. A magnetic field gradient induces a Zeeman shift of the resonances and transforms the frequency information into spatial information, which allows for the simultaneous analysis of the microwave signal in the entire frequency bandwidth of the device. The time dependent spectral analysis of an amplitude modulated microwave signal is demonstrated over a bandwidth of 600 MHz, associated to a frequency resolution of 7MHz , and a refresh rate of 4 ms. With such integration time, a field of a few hundreds of lW can be detected. Since the optical properties of NV centers can be maintained even in high magnetic field, we estimate that an optimized device could allow frequency analysis in a range of 30 GHz, only limited by the amplitude of the magnetic field gradient. In addition, an increase of the NV centers quantity could lead both to an increase of the microwave sensitivity and to a decrease of the minimum refresh rate down to a few ls.

We present the controlled creation of single nitrogen-vacancy (NV) centers via ion implantation at the center of a photonic crystal cavity which is fabricated in an ultrapure, single crystal diamond membrane. High-resolution placement of NV centers is achieved using collimation of a 5 keV-nitrogen ion beam through a pierced tip of an atomic force microscope. We demonstrate coupling of the implanted NV centers’ broad band fluorescence to a cavity mode and observe Purcell enhancement of the spontaneous emission. The results are in good agreement with a master equation model for the cavity coupling.

This paper investigates the relationship between vacant job positions and unemployed workers, illustrated by the Beveridge curve, a tool for observing the matching process and the condition of a labour market. The Swedish case is studied together with its three largest labour market regions, i.e., Stockholm-, Västra Götaland- and Skåne county. A comparison opens up a discussion of whether local labour markets with similar characteristics located in different parts of the country behave similarly or in what way they distinguish. Furthermore, these three regions are expected to influence the Swedish Beveridge curve to a larger extent, which is also examined in the paper. In addition, the effect of an exogenous shock, such as the building of the Öresund Bridge, expanding the labour market of Skåne county by connection to another metropolitan area, Copenhagen, is studied. This is done by comparing the matching efficiency before and after the bridge is opened. Moreover, the effect in Skåne is then analysed in accordance with the same period for the other regions included, to get an indication of whether the bridge alone provides a change in matching efficiency or if changes are connected to national events that influence all regions similarly.  The analysis is based on monthly data from year 1996-2020, collected from the Swedish Public Employment service and Statistics Sweden, primarily. Graphical illustrations of the Beveridge curve in combination with OLS regressions provide concluding results that the Beveridge curves for the three regional labour markets observed are shaped rather similarly and experience shifts and movements during the same time points, generally. Skåne county is the exception and experience more horizontal and vertical movements compared to Stockholm- and Västra Götaland county and the Swedish average. Furthermore, there are statistically significant estimates ensuring the negative relationship between unemployment- and vacancy rate, i.e., a downward sloping Beveridge curve for all regions. Not enough evidence on the effect of the Öresund Bridge on the matching efficiency of Skåne county is provided to present a valid conclusion regarding this topic.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23221号 / 工博第4865号 / 新制||工||1759(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 水落 憲和, 教授 浜地 格, 教授 SIVANIAH Easan / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13240号 / 論工博第4178号 / 新制||工||1720(附属図書館) / (主査)教授 木本 恒暢, 教授 藤田 静雄, 教授 山田 啓文 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Des amas de lacunes ont été observés et caractérisés expérimentalement dans les métaux de haute pureté après déformation plastique ou après une suite de traitements thermiques particuliers. Ces amas sont des obstacles à la propagation des dislocations et peuvent par conséquent induire un durcissement du métal.Cette étude par simulations numériques a permis d'explorer différents mécanismes de propagation de dislocations dans une concentration d'amas en fonction de la contrainte de cisaillement appliquée et de la température. À haute contrainte, la force appliquée sur la dislocation devient supérieure aux forces d'ancrage s’exerçant sur la ligne. La dislocation franchit la distribution d'amas en glissant et en cisaillant les amas. La dépendance de la force d'ancrage en fonction de la taille de l'amas est ajustée sur nos simulations de statique moléculaire. Dans ce domaine de contrainte, les configurations d'amas ancrant la dislocation sont rares et l'activation thermique suffit à désancrer la ligne. La probabilité de désancrer la ligne dépend de l'enthalpie d'activation, un paramètre que nous avons également estimé à l'aide d'un modèle analytique ajusté sur nos résultats atomistiques. À plus faible contrainte, lorsque la force appliquée est inférieure aux forces d'ancrage induites par les amas, la probabilité que la dislocation se désancre uniquement par glissement devient faible. La diffusion des lacunes, émises préférentiellement des amas, intervient alors et favorise la formation de crans. Cela contribue au désancrage de la ligne. Ce mécanisme est le glissement assisté par la montée. Les barrières d'émission, d'absorption et de migration de lacunes ont été déterminées par statique moléculaire et sont fortement dépendantes du champ élastique et de la distorsion du réseau atomique générés par la présence de la dislocation. Cela induit une forte anisotropie de diffusion au voisinage des dislocations qui conduit notamment au mécanisme de 'pipe diffusion'. L'évolution au cours du temps de l'ensemble de ces mécanismes a été étudiée à l'aide d'un modèle de ligne élastique couplé à un algorithme de Monte Carlo cinétique dont l'ensemble des barrières d'énergie provient de nos simulations atomistiques. Moyennant les hypothèses du modèle, nous avons alors obtenu une estimation de la vitesse des dislocations en fonction de la contrainte et de la température appliquée. Nous avons ensuite utilisé la loi d'Orowan pour estimer la vitesse de déformation liée à ces mécanismes. / Vacancy clusters have been observed and characterized experimentally in highly pure metals after plastic deformation or after a particular sequence of heat treatments. These clusters hinder the dislocation propagation and can therefore harden the metal.Using numerical simulations we have explored different mecanisms of dislocation propagation through a vacancy-cluster distribution, for several applied shear stress and temperature. At high stresses, the force applied on the dislocation becomes greater than the pinning forces acting on the line. The dislocation gets through the cluster distribution by gliding and shearing the clusters. The dependence of the pinning force with the cluster size is adjusted on our molecular static simulations. In this stress range, the pinning configurations are rare and the thermal activation is sufficient to unpin the line. The probability for the line to pass the pinning configuration depends on the activation enthalpy, a parameter that we have also estimated using an analytical model adjusted on our atomistic results. At lower stresses, when the applied force is below the pinning forces induced by the cluster, the probability that the dislocation unpins by pure glide becomes negligeable. The diffusion of vacancies, emitted preferentially from the vacancy clusters, intervenes and promotes the formation of jogs that contributes to the unpinning of the line. Such a mecanism is the glide assisted by climb. The emission, the absorption and the vacancy migration barriers have been determined by molecular static and are highly dependent on the elastic field and the atomic network distortion induced by the dislocation. This promotes a strong diffusion anisotropy in the vicinity of the dislocations which leads in particular to the pipe diffusion mechanism. The evolution with time of all these mechanisms has been studied using an elastic line model coupled to a kinetic Monte Carlo algorithm in which the parameters come from our atomistic simulations. According to the model assumptions, we obtained an estimation of dislocation velocity as a function of the applied shear stress and the temperature. We used the Orowan's law to estimate the strain rate related to such mechanisms.