The Rising Above the Gathering Storm report (National Academy of Sciences, 2007) emphasizes a need for improved science education in United States schools. Instruction, informed by assessment, has been repeatedly demonstrated to be effective for increasing students' performance. In particular, the use of curriculum-based measurement (CBM) to assist with making screening decisions has been shown to increase the likeliness of students meeting meaningful outcomes. While CBM tools for assisting with making screening decisions in reading, mathematics, and written language have been well examined, tools for use in content areas (e.g., science and social studies) remain in the beginning stages of research. In this study, two alternate forms of a new CBM tool, Statement Verification for Science (SV-S), for assisting with making screening decisions regarding students' science content knowledge is examined for technical adequacy. A total of 1,545 students across Grades 7 (N = 799) and 8 (N = 746) completed Forms A and B of SV-S the week prior to, and within two weeks after, a statewide high-stakes test of accountability including Science, Reading, and Mathematics. Obtained data were used in order to examine internal consistency, test-retest with alternate forms reliability, and evidence of criterion- and construct-related validity. Promising results were found for reliability, in particular internal consistency, while results related to evidence of criterion- and construct-related validity were less than desired. Such results, along with additional exploratory analyses, provide support for future research of SV-S as a CBM tool to assist teachers and other educators with making screening decisions.

Abstract This report describes our ten week long thesis work which is the last task in our education in mechanical engineering at Linköpings University. The project has been performed at Siemens Industrial Turbomachinery AB’s service department. The company which is located in Finspång produces, sells and provides service for steam and gas turbines around the world. The purpose of this project is to help Siemens develop their maintenance programs for two of the auxiliary systems which are a part of the complete steam turbine system. These are lube and control oil systems. The project is restricted to two of Siemens maintenance products, No Stop Check (NSC) and the annual Safety Inspection (SI). Some parts of the major and limited overhauls have also been investigated. During the work different maintenance concepts have been investigated and evaluated. Focus has been centered on finding possible solutions that allow maintenance work while the steam turbine system is running. The economical consequences are enormous if the turbine has to be shut down. This due to today’s expanded capacity of the plants. Many discussions and interviews have taken place during the project. Information has also been obtained from documents, literature and the Internet. A Failure Mode and Effect Criticality Analysis (FMECA) has also been input for the task, especially while maintenance measures and concepts were discussed. The present maintenance that Siemens supplies are mostly based on time and experience. We have tried to implement a more condition based maintenance. A lot of time has therefore been spent finding methods for reliable measuring of the machinery condition. The work has generated a lot of different recommendations for the future maintenance. These are more or less condition based and tailor-made for Siemens steam turbine systems. We hope that these propositions will be used in the future maintenance work and also to give some new ideas on how to develop the condition based maintenance at Siemens. / Sammanfattning Denna rapport beskriver vårt tio veckor långa examensarbete som är den avslutande delen i vår maskiningenjörsutbildning. Arbetet har utförts vid serviceavdelning på Siemens Industrial Turbomachinery AB (Siemens). Siemens som ligger i Finspång tillverkar, säljer och servar ång - och gasturbinanläggningar över hela världen. Syftet med arbetet är att hjälpa Siemens att utveckla sina serviceprogram för två av de kringsystem som ingår i en ångturbinanläggning, dessa är smörj- och hydrauloljesystem. Arbetet är avgränsat till två av Siemens serviceprodukter, No Stop Check (NSC) och Säkerhetsinspektion (SI). Även vissa delar av de större revisionerna har undersökts. I arbetet har olika underhållsfilosofier undersökts och utvärderats. Fokus har riktats mot att undersöka möjligheter att utföra underhållsåtgärder med turbinanläggningen i drift. I och med den höga kapacitet dagens ångturbinanläggningar har blir de ekonomiska förlusterna enormt stora vid ett eventuellt produktionsbortfall. Under arbetets gång har många diskussioner och intervjuer ägt rum. Information har också inhämtats genom dokument, böcker och Internet. En så kallad Failure Mode and Effect Criticality Analysis (FMECA) har också legat till grund för arbetet när metoder och åtgärder för underhållet diskuterats. Siemens nuvarande underhåll är till stor del erfarenhets- och tidsbaserat. Vi har försökt att applicera ett mer tillståndsbaserat underhåll och därför har mycket tid ägnats åt att hitta metoder att tillståndskontrollera utrustningen med. Arbetet har genererat ett flertal olika rekommendationer på underhållsaktiviteter som är tillståndsbaserade och anpassade för Siemens turbinanläggningar. Tanken är att dessa förslag ska användas i det fortsatta underhållsarbetet och dessutom väcka idéer till fortsatt utveckling av tillståndsbaserat underhåll.

<p>Abstract</p><p>This report describes our ten week long thesis work which is the last task in our education in mechanical engineering at Linköpings University. The project has been performed at Siemens Industrial Turbomachinery AB’s service department. The company which is located in Finspång produces, sells and provides service for steam and gas turbines around the world.</p><p>The purpose of this project is to help Siemens develop their maintenance programs for two of the auxiliary systems which are a part of the complete steam turbine system. These are lube and control oil systems.</p><p>The project is restricted to two of Siemens maintenance products, No Stop Check (NSC) and the annual Safety Inspection (SI). Some parts of the major and limited overhauls have also been investigated.</p><p>During the work different maintenance concepts have been investigated and evaluated. Focus has been centered on finding possible solutions that allow maintenance work while the steam turbine system is running. The economical consequences are enormous if the turbine has to be shut down. This due to today’s expanded capacity of the plants.</p><p>Many discussions and interviews have taken place during the project. Information has also been obtained from documents, literature and the Internet. A Failure Mode and Effect Criticality Analysis (FMECA) has also been input for the task, especially while maintenance measures and concepts were discussed.</p><p>The present maintenance that Siemens supplies are mostly based on time and experience. We have tried to implement a more condition based maintenance. A lot of time has therefore been spent finding methods for reliable measuring of the machinery condition.</p><p>The work has generated a lot of different recommendations for the future maintenance. These are more or less condition based and tailor-made for Siemens steam turbine systems. We hope that these propositions will be used in the future maintenance work and also to give some new ideas on how to develop the condition based maintenance at Siemens.</p> / <p>Sammanfattning</p><p>Denna rapport beskriver vårt tio veckor långa examensarbete som är den avslutande delen i vår maskiningenjörsutbildning. Arbetet har utförts vid serviceavdelning på Siemens Industrial Turbomachinery AB (Siemens). Siemens som ligger i Finspång tillverkar, säljer och servar ång - och gasturbinanläggningar över hela världen.</p><p>Syftet med arbetet är att hjälpa Siemens att utveckla sina serviceprogram för två av de kringsystem som ingår i en ångturbinanläggning, dessa är smörj- och hydrauloljesystem.</p><p>Arbetet är avgränsat till två av Siemens serviceprodukter, No Stop Check (NSC) och Säkerhetsinspektion (SI). Även vissa delar av de större revisionerna har undersökts.</p><p>I arbetet har olika underhållsfilosofier undersökts och utvärderats. Fokus har riktats mot att undersöka möjligheter att utföra underhållsåtgärder med turbinanläggningen i drift. I och med den höga kapacitet dagens ångturbinanläggningar har blir de ekonomiska förlusterna enormt stora vid ett eventuellt produktionsbortfall.</p><p>Under arbetets gång har många diskussioner och intervjuer ägt rum. Information har också inhämtats genom dokument, böcker och Internet. En så kallad Failure Mode and Effect Criticality Analysis (FMECA) har också legat till grund för arbetet när metoder och åtgärder för underhållet diskuterats.</p><p>Siemens nuvarande underhåll är till stor del erfarenhets- och tidsbaserat. Vi har försökt att applicera ett mer tillståndsbaserat underhåll och därför har mycket tid ägnats åt att hitta metoder att tillståndskontrollera utrustningen med.</p><p>Arbetet har genererat ett flertal olika rekommendationer på underhållsaktiviteter som är tillståndsbaserade och anpassade för Siemens turbinanläggningar. Tanken är att dessa förslag ska användas i det fortsatta underhållsarbetet och dessutom väcka idéer till fortsatt utveckling av tillståndsbaserat underhåll.</p>

The focus of this thesis is the development of Resistive Plate Chambers (RPCs) with ceramic electrodes. The use of ceramic composites, Si3N4/SiC, opens the way for the application of RPCs in harsh radiation environments. Future Experiments like the Compressed Baryonic Matter (CBM) at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt will need new RPCs with high rate capabilities and high radiation tolerance. Ceramic composites are specially suited for this purpose due to their resistance to radiation and chemical contamination. The bulk resistivity of these ceramics is in the range 10^7 - 10^13 Ohm cm. The bulk resistivity of the electrodes is the main factor determining the rate capabilities of a RPC, therefore a specifific measuring station and a measurement protocol has been set for these measurements. The dependence of the bulk resistivity on the difffferent steps of the manufacturing process has been studied. Other electrical parameters like the relaxation time, the relative permittivity and the tangent loss have also been investigated. Simulation codes for the investigation of RPC functionality was developed using the gas detectors simulation framework GARFIELD++. The parameters of the two mixtures used in RPC operation have been extracted. Furthermore, theoretical predictions on time resolution and effi ciency have been calculated and compared with experimental results. Two ceramic materials have been used to assemble RPCs. Si3N4/SiC and Al2O3 with a thin (nm thick) chromium layer deposited over it. Several prototypes have been assembled with active areas of 5x 5 cm^2, 10x 10 cm^2 and 20 x20 cm^2. The number of gaps ranges from two to six. The gas gap widths were 250 micro meter and 300 micrometer. As separator material mylar foils, fifishing line and high-resistive ceramics have been used. Different detector architectures have been built and their effffect on RPC performance analysed. The RPCs developed at HZDR and ITEP (Moscow) were systematically tested in electron and proton beams and with cosmic radiation over the course of three years. The performance of the RPCs was extracted from the measured data. The main parameters like time resolution, effi ciency, rate capabilities, cluster size, detector currents and avalanche charge were obtained and compared with other RPC systems in the world. A comparison with phenomenological models was performed.

Pour réduire notre empreinte carbone sur l’environnement, il est urgent de développer des procédés industriels utilisant une source de carbone renouvelable comme la biomasse lignocellulosique. La paroi cellulaire végétale est un enchevêtrement complexe de cellulose, d’hémicelluloses et de lignines. Elle résiste aux attaques biologiques et chimiques mais limite le développement d’une bioéconomie responsable. Dans la Nature, des enzymes multimodulaires produites par certains microorganismes peuvent la déconstruire. Toutefois, ces enzymes sont majoritairement étudiées sur des substrats artificiels ou purifiés. Dans cette thèse, nous proposons de les étudier sur des substrats broyés puis des coupes de paille de blé brutes. Les enzymes multimodulaires sont préparées à façon en utilisant la propriété d’association covalente des protéines Jo et In. Nous avons ainsi associé la xylanase NpXyn11A de N. patriciarum avec deux modules non catalytiques : le CBM3a de C. thermocellum ou le CBM2b1 C. fimi ciblant la cellulose ou les xylanes respectivement. Les propriétés biochimiques de ces protéines chimériques ont été comparées aux modules sauvages. L’activité enzymatique des protéines chimériques a ensuite été étudiée sur des substrats solubles, jusqu’à des substrats insolubles comme le son et la paille de blé, notamment par immunocytochimie. Ce travail a mis en évidence l’importance de la relation enzymes/substrats pour une caractérisation in muro d’activité enzymatique et une meilleure compréhension de la déconstruction de la biomasse végétale. / In order to reduce our carbon footprint on the environment, it is more than urgent to develop new industrial process using a renewable carbon source such as lignocellulosic biomass. Plant cell walls consist of a complex network of cellulose, hemicelluloses and lignins that cross-link with each other mainly via non-covalent bonds. It is thus hardly surprising that plant biomass is rather recalcitrant to chemical or biological degradation. In the present era marked by the desire to build a green bioeconomy, this recalcitrance remains a key point. In Nature, the plant-based organic carbon contained within plant cell walls is mainly recycled by the action of cellulolytic microorganisms, producing multimodular enzymes. However, these enzymes are mainly characterized on artificial or purified substrates. In this thesis, we proposed to study multimodular enzymes on raw substrates such as wheat straw sections. The studied multimodular enzymes were associated thanks to the use of two small proteins Jo and In. Thus, we associated the xylanase NpXyn11A from N. patriciarum with two non-catalytic modules: CBM3a from C. thermocellum or CBM2b1 from C. fimi targeting cellulose or xylans respectively. Biochemical properties of these chimeric proteins and wild-type modules have been compared. The enzymatic activity of chimeric proteins has been studied on soluble substrates and compared to the activity on insoluble substrates, mainly by immunocytochemistry. This work highlighted the importance of the relationship enzymes/substrates and its key role to better understand the biomass deconstruction in muro.

Dans le contexte de la bioéconomie, la découverte et la caractérisation des enzymes capables de dégrader la paroi végétale est particulièrement intéressante pour l’utilisation de la biomasse lignocellulosique dans l’industrie. A cet égard, la métagénomique fonctionnelle est un outil puissantpour découvrir de nouvelles enzymes à partir d’écosystèmes microbiens variés, comme l’illustrent les travaux sur le tube digestif du termite Pseudacanthotermes militaris. Cette étude a fourni une mine d’informations et identifié un hypothétique locus d’utilisation du xylane (XUS), codant pour cinq glycosides hydrolases (GH) et une carbohydrate esterase (CE) de Bacteroidales.Le XUS du métagénome de Pseudacanthotermes militaris contient une xylanase de la famille GH10 qui possède une organisation modulaire complexe dans laquelle la séquence du domaine GH10 est interrompue par une insertion de deux carbohydrate binding modules (CBM). Des travaux préliminaires ont montré que cette enzyme modulaire, désignée Pm25, est active sur xylane. Par conséquent, un des objectifs de cette étude a été la caractérisation détaillée des propriétés biochimiques et catalytiques de Pm25. Le rôle des CBM a également été examiné en quantifiant les interactions protéines-sucres et permettant ainsi une meilleure compréhension du rôle spécifique de ces modules, les résultats obtenus permettent de cerner l’impact de la modularité de Pm25 sur ses propriétés fonctionnelles.Dans une deuxième partie de l’étude, nous avons entrepris d’étudier la fonction de Pm25 dans le contexte du cluster XUS. Pour ce faire, nous avons étudié les enzymes adjacentes à Pm25 sur le locus,une autre GH10, une GH11, une GH115 et une GH43. La comparaison des paramètres cinétiques et une étude détaillée des produits d’hydrolyse ont été analysés par spectrométrie de masse et ont révélé que la GH10 et la GH11 étaient les enzymes clefs de la dépolymérisation en étant 20 fois plus efficaces que Pm25. En parallèle, nous avons développé un protocole pour l’utilisation de la micro-thermophorèse (MST) pour quantifier les interactions CBM-sucres, une approche intéressante qui nécessite peut d’échantillon et de ligand contrairement à d’autres méthodes biophysiques. Dans l’ensemble, cette étude a révélé le rôle important de Pm25 et ses homologues dans les locus d’utilisation des xylanes chez les Bacteroidetes et a permis d’identifié le sens de cette architecture particulière. / In the context of bioeconomy, the discovery and study of plant-cell wall degrading enzymes is particularly relevant for the use of lignocellulosic biomass for industrial purposes. In this respect, functional metagenomics has proven to be a powerful tool to discover new enzymes from a variety of microbial ecosystems, as exemplified by work performed on the gut of the termite Pseudacanthotermes militaris. This study provided a wealth of information and identified an interesting hypothetical xylan utilization system, encoding five glycoside hydrolases (GH) and one carbohydrate esterase (CE) annotated from bacteroidales. The Pseudacanthotermes militaris-derived putative XUS cluster contains a GH10 xylanase that displays a quite complex modular arrangement wherein the GH10 catalytic module contains two insertional carbohydrate binding modules (CBM). During the preliminary work, this modular enzyme, designated Pm25, was shown to be active on xylan, thus in the present research we set out to more thoroughly characterize its biochemical and catalytic properties.The role of the CBM was also investigated, quantifying protein-carbohydrate interactions and thus providing better insight into the specific role of the modules. Taken together, the results obtained provide insight into how Pm25 modularity translates into functional properties. In second part of our study, we set out investigate the function of Pm25 in the context of the XUS cluster. To achieve this we studied a xylan utilization system, which is constituted by another GH10, GH11, GH115 and GH43. The comparison of kinetic parameters and a detailed end product analysis by mass spectrometry showed that GH10 and GH11 outweigh over 20 fold Pm25 catalytic efficiency. In parallel, we developed the use of MicroScale Thermophoresis (MST) to quantify CBM-carbohydrates interactions, an interesting approach requiring smaller concentration of proteinsand ligands compared to other biophysical methods. Overall this study highlighted the important role of Pm25 homologs in the xylan utilization system in Bacteroidetes, and pinpointed the meaning of its unusual architecture.

[pt] Os mecanismos envolvidos na produção de metano e no sequestro de CO2 no carvão são complexos, tendo em vista grande quantidades de fatores envolvidos no processo. O entendimento do comportamento mecânico do carvão assim como a caracterização de sistema poroso é de fundamental importância para o êxito de um projeto de explotação. Esse trabalho visou à caracterização de amostras de carvão oriundas da camada Barro Branco. A fim de caracterizar o sistema poroso do material, uma campanha de análises foi programada como: microtomógrafo, microscopia eletrônica de varredura (MEV), micropermiametria e porosimetria por injeção a mercúrio. Ensaios mecânicos foram realizados visando à caracterização mecânica do material e a validação de um modelo constitutivo. O carvão apresentou comportamentos mecânicos de resistência e deformabilidade consistentes e com pouca variabilidade, o que permitiu um ajuste confiável da envoltória de resistência de Mohr-Coulomb bem como o do modelo constitutivo elastoplástico de Lade-Kim. / [en] Mechanisms involved in geological storage of CO2 and eventual production of methane are complex due to a number of different factors involved. One of the important factors to be taken into account is the geomechanical behaviour of coal, key to the success of the exploration as well as the characterization of the pore structure of the material.Coal can be regarded as a sedimentary rock possessing two perpendicular families of microfissures called cleats.This work presents results of an experimental program aiming at the characterization of the mechanical properties of coal from the Barro Branco formation. A constitutive model (Lade-Kim s model) was tested in order to check its validity in the representation of the stress-strain-strength behaviour of the coal. Lade-Kim s model is well accepted for the representation of the mechanical behaviour of soft rocks. Furthermore, in order to characterize the porous structure of the material, a number of tests were performed such as: X Ray Micro CT scan, scanning electron microscopy, minipermeameter determination of permeability and mercury injection porosimetry.

Les émissions de CO2 dans l'atmosphère sont reconnues comme ayant un effet significatif sur le réchauffement climatique. Le stockage géologique de CO2 est largement considéré comme une approche essentielle pour réduire l'impact de telles émissions sur l'environnement. De plus, injecter du dioxyde de carbone dans les veines de charbon remplies de méthane présent naturellement facilite la récupération de ce méthane, un processus connu sous le nom de récupération assistée du méthane des veines de charbon (ECBM en anglais). Mais le gonflement de la matrice de charbon induite par l'adsorption préférentielle de dioxyde de carbone par rapport au méthane conduit à la fermeture du système de cleats (un ensemble de petites fractures naturelles) du réservoir et donc à une perte d'injectivité. Cette thèse de doctorat est consacrée à l'étude de comment cet injectivité évolue en présence de fluides. Nous dérivons deux modèles poromécaniques à double porosité pour une veine de charbon saturée par un liquide pur. Les équations constitutives obtenues permettent de mieux comprendre et modéliser le lien entre injectivité de la veine de charbon et gonflement du charbon induit par l'adsorption. Pour les deux modèles, on considère l'espace poreux du réservoir comme divisé en les cleats macroporeuses et les pores de la matrice de charbon. Les deux modèles diffèrent dans la manière dont l'adsorption de fluide est prise en compte : le premier modèle est limité à une adsorption surfacique, tandis que le deuxième modèle peut être appliqué à l'adsorption dans un milieu possédant un réseau poreux générique, et donc dans un milieu microporeux comme le charbon, pour lequel l'adsorption se déroule principalement par remplissage de micropores. Le second modèle est calibré sur deux charbons avec des propriétés de sorption et de gonflement différentes. Nous effectuons alors des simulations à différentes échelles (du Volume Élémentaire Représentatif, de l'échantillon de charbon, la veine de charbon). En particulier, nous validons notre modèle sur des données expérimentales de variations de perméabilité de charbon induites par l'adsorption. Nous effectuons aussi des simulations de veines dont le méthane serait produit (un processus connu sous le nom de CBM en anglais) ou de veines sans méthane dans lesquelles du CO2 serait injecté. Nous étudions l'effet de différents paramètres tels que les conditions aux limites, la compressibilité de la matrice de charbon, ou la cinétique de transfert de liquide entre les cleats et la matrice de charbon. Dans une dernière partie, le modèle dérivé est étendu aux cas pour lesquels le charbon est en présence de mélanges fluides binaires tels que les mélanges de méthane et le dioxyde de carbone. Nous calibrons entièrement calibré ce modèle étendu sur des données disponibles obtenues expérimentalement et par simulations moléculaires. Des calculs sont alors effectués à l'échelle d'un Volume Élémentaire Représentatif pour prévoir comment sa porosité et sa perméabilité varient en présence de mélanges fluides de méthane et de dioxyde de carbone / CO2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poromechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO2 would be injected. We study the effect of various parameters such as boundary conditions, compressibility of the coal matrix, or kinetics of transfer of fluid between cleats and coal matrix. In a final part, the derived model is extended to cases for which coal is in presence of fluid binary mixtures such as mixtures of methane and carbon dioxide. We fully calibrate this extended model on available data obtained experimentally and by molecular simulations. Calculations are then performed at the scale of a Representative Elementary Volume in order to predict how its porosity and its permeability vary in presence of fluid mixtures of methane and carbon dioxide

The focus of this thesis is the development of Resistive Plate Chambers (RPCs) with ceramic electrodes. The use of ceramic composites, Si3N4/SiC, opens the way for the application of RPCs in harsh radiation environments. Future Experiments like the Compressed Baryonic Matter (CBM) at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt will need new RPCs with high rate capabilities and high radiation tolerance. Ceramic composites are specially suited for this purpose due to their resistance to radiation and chemical contamination. The bulk resistivity of these ceramics is in the range 10^7 - 10^13 Ohm cm. The bulk resistivity of the electrodes is the main factor determining the rate capabilities of a RPC, therefore a specifific measuring station and a measurement protocol has been set for these measurements. The dependence of the bulk resistivity on the difffferent steps of the manufacturing process has been studied. Other electrical parameters like the relaxation time, the relative permittivity and the tangent loss have also been investigated. Simulation codes for the investigation of RPC functionality was developed using the gas detectors simulation framework GARFIELD++. The parameters of the two mixtures used in RPC operation have been extracted. Furthermore, theoretical predictions on time resolution and effi ciency have been calculated and compared with experimental results. Two ceramic materials have been used to assemble RPCs. Si3N4/SiC and Al2O3 with a thin (nm thick) chromium layer deposited over it. Several prototypes have been assembled with active areas of 5x 5 cm^2, 10x 10 cm^2 and 20 x20 cm^2. The number of gaps ranges from two to six. The gas gap widths were 250 micro meter and 300 micrometer. As separator material mylar foils, fifishing line and high-resistive ceramics have been used. Different detector architectures have been built and their effffect on RPC performance analysed. The RPCs developed at HZDR and ITEP (Moscow) were systematically tested in electron and proton beams and with cosmic radiation over the course of three years. The performance of the RPCs was extracted from the measured data. The main parameters like time resolution, effi ciency, rate capabilities, cluster size, detector currents and avalanche charge were obtained and compared with other RPC systems in the world. A comparison with phenomenological models was performed.

Sustainability is well-publicized in society, and in order to achieve sustainability, there are arguments for switching to or introducing circular economy and circular business models. Previous studies have shown that SMEs have difficulty switching to a circular economy due to barriers that complicates that process. In this qualitative, exploratory study, nine SMEs are interviewed to examine the obstacles SMEs face in their work and transition to a circular organization, with the aim of contributing to in-depth understanding. The interviews are analyzed thematically, resulting in five themes: human reactions, business restructuring, financial assets and distribution, knowledge and ability, and legislation, which are the practical and theoretical contributions of this study.  The conclusions of the work are that the majority of companies experience obstacles of a financial and cultural nature, and in order to overcome these obstacles, the majority believe that the key to success is to prioritize, educate and act. / Hållbarhet är väl omtalat i samhället, och för att uppnå hållbarhet finns det argument för att övergå till eller införa cirkulär ekonomi och cirkulära affärsmodeller. Tidigare studier har visat på att SME har svårt att övergå till en cirkulär ekonomi p.g.a. hinder som försvårar den processen. I den här kvalitativa, explorativa studien intervjuas nio SME för att undersöka vilka hinder SME möter i arbetet och omställningen mot en cirkulär verksamhet, med syftet att bidra till fördjupad förståelse. Intervjuerna analyseras tematiskt vilket resulterar i fem teman: mänskliga reaktioner, omstrukturering av verksamheten, ekonomiska tillgångar och fördelning, kunskap och förmåga samt lagstiftning, vilka är det praktiska och teoretiska bidraget med den här studien.  Slutsatserna med arbetet är att majoriteten av företagen upplever hinder av finansiell och kulturell karaktär, och för att överkomma dessa hinder tror majoriteten att faktorer för framgång är att prioritera, utbilda och agera.