Studien undersöker hur ett byggföretag som arbetar med prefabricering kan standardisera dess produktionsprocess och stödaktiviteter. Studien försöker även genom reducering eller eliminering av slöseri förbättra processcykel effektiviteteten. Studien genomförs på ett fallföretag. Fallföretaget är nystartat och tillverkar modulhus och element. Fallföretaget saknar ett standardiserat produktionsflöde och arbetsuppgifter. Det råder också kommunikationsbrister då majoriteten av operatörerna är första generationens invandrare från olika länder. Studien kommer genom mätningar och observationer fram till att en anläggningsplanering med ett standardiserat produktionsflöde och fasta arbetsstationer kan minska slöseri och för att förbättra processcykel effektiviteten hos fallföretaget

Part 1 The scientific community has identified an attitude-action gap for demographic and psychographic variables when studying sustainable purchase behaviour. By focusing on what happens during the purchase instead of the purchaser, this cross-sectional study aims to understand sustainable purchase behaviour when consumers purchase sustainable food. The scope of this study focused on the consumer’s perceived degree of Confidence and Com- promise when purchasing sustainable food products as suggested by Peattie in the Green purchase perception matrix. However, since the study included environmental and social responsibility, we renamed the matrix to the Sustainable purchase perception matrix. The focus was also on a new construct created in this study called the Sustainable lead consumer. The degree of Confidence was measured through the consumer’s own belief in the ability to have a positive sustainability impact, i.e. Perceived consumer effectiveness (PCE) and the consumer’s domain-specific sustainability interests. The degree of Compromise was measured through the consumer’s Willingness to pay (WTP) for certain sustainability attributes. The data was collected through a questionnaire (N=436), and the result showed that the correlation between consumers’ WTP and PCE was weak, positive and significant within the sustainability interests Organic food, Animal welfare and Natural resources. As mentioned, Confidence and Compromise was examined through the variables PCE, sustainability interests and WTP. To reveal if the consumers experienced other variables within Confidence and Compromise a thematic analysis of consumers’ perceived scepticism towards sustainability marketing was conducted. The result identified 15 themes that could be associated with the variable Confidence and 17 themes that could be associated with the variable Compromise. By creating a new construct, the Sustainable lead consumer, the study identified a consumer who was considered ahead of the sustainability trend and benefited greatly from solutions in this trend. The correlation between WTP and domain-specific sustainability interests for Sustainable lead consumers was non-significant but strong (n=377). When comparingSustainable lead consumers’ WTP to the remaining population, the Wilcoxon rank-sum test showed no significant evidence that the Sustainable lead consumers had a higher WTP for their domain-specific sustainability interests. A potential attitude-action gap among the Sustainable lead consumers was examined by evaluating if a high degree of Confidence and Compromise led to actual sustainable purchase behaviour. The analysis showed that only a small proportion of Sustainable lead consumers with a high degree of PCE and WTP had an actual sustainable purchase behaviour. This was likely due to the existing attitude-action gap where the consumers’ attitude is not reflected in their actual behaviour. Part 2 Food production and consumption have a major impact on the environment, primarily from agriculture, but also from the processing of food, transportation and waste management. Increased environmental awareness among consumers has led to a demand for transparency in the food production chain and thus an increased demand for knowledge about food’s environmental impact. By studying the environmental impact of the product BäR smoothie from the Finnish company Toripiha, this study aims to identify environmental hotspots in the product’s production chain. A life cycle assessment (LCA) was conducted in accordance with the ISO standards ISO 14040 and ISO 14044, to investigate the environmental impact of a bottle of BäR smoothie á 250 ml. The LCA was attributional, meaning that it aims to depict the product’s environmental impact over its life cycle. The environmental impact categories global warming, eutrophication and primary energy use were included, and measured with the impact category indicators carbon dioxide equivalents (CO2-eq), phosphate equivalents (PO4-eq) and megajoule (MJ). Inventory data were collected mainly from the database Ecoinvent version 3.7, but also from scientific articles and previous studies, as well as the calculation tool NTMCalc Basic 4.0. The results of this study highlight the parts of the production chain of BÄR smoothie that have the most significant environmental impact concerning the chosen impact categories. A bottle of BäR smoothie á 250 ml contributed to a total of 120 g CO2-eq, 0.39 g PO4-eq and 2.8 MJ. The smoothie bottle, i.e. the production of the virgin bottle grade PET granulate (vPET) and recycled bottle grade PET granulate (rPET), had the largest impact on global warming and primary energy use of all the components, and also had a significant impact on eutrophication. As most of this contribution comes from the production of vPET granulate, Toripiha was advised to purchase bottles that have a higher content of rPET granulate to decrease the smoothie’s environmental impact. It was also evident that the transportation of components was a significant contributor to global warming, eutrophication and primary energy use. Since transportation had such an impact on the result, Toripiha needs to strive towards short and efficient transport of the different components to reduce the environmental impact from transportation. / Del 1  Forskare inom hållbart konsumtionsbeteende har identifierat en diskrepans mellan attityd och beteende för demografiska och psykografiska variabler. Genom att studera vad som händer hos konsumenten under ett köp, i stället för tidigare nämnda variabler, vill denna tvärsnittsstudie identifiera vad som driver hållbart konsumtionsbeteende av livsmedel. Denna studie fokuserade på konsumenters upplevda nivå av Confidence och Compromise vid köp av hållbar mat så som föreslås av Peattie’s Green purchase perception matrix. Dock så användes matrisen till att studera både miljömässig och social hållbarhet och döptes således om till Sustainable purchase perception matrix. Studien undersökte även ett nytt koncept som skapades i detta examensarbete, nämligen Sustainable lead consumer adapterat från Von Hippel’s Lead user. Graden av Confidence mättes genom att studera konsumentens tro på den egna förmågan att ha en positiv hållbarhetspåverkan, dvs. Percieved consumer effectiveness (PCE), samt domän-specifika hållbarhetsintressen. Graden av Compromise mättes genom konsumentens villighet att kompromissa genom att betala för olika hållbarhetsattribut, även kallat Willingness to pay (WTP). Data samlades in genom en enkät (N=436), och resultatet visade att det fanns en svag, positiv och signifikant korrelation mellan PCE och WTP inom hållbarhetsintressena Ekologisk mat, Djurvälfärd och Naturresurser. Vidare utfördes en tematisk analys av kvalitativ data för att studera vilka andra variabler än hållbarhetsintressen, WTP och PCE som påverkade variablerna Confidence och Compromise. Detta resulterade i 15 teman som kunde relateras till Confidence och 17 teman till Compromise. Genom att skapa ett nytt koncept, Sustainable lead consumer, identifierade denna studie en konsument som ansågs vara i framkant av hållbarhetstrenden och som drog stora fördelar av denna trend. Korrelationen mellan WTP och Sustainable lead consumer’s var stark men ej signifikant (n=377). När dessa konsumenter jämfördes med resterande population, visade Wilcoxon rank-sum test inga signifikanta bevis på att Sustainable lead consumer’s hade ett högre WTP än resterande population. Huruvida en attityd och beteende diskrepans existerade för Sustainhable lead consumers studerades genom att se om en hög grad av Confidence och Compromise ledde till en högre av hållbar konsumtionsbeteende. Analysen visade att det endast var en liten andel av Sustainable lead consumers med ett högt PCE och WTP som också hade ett hållbart konsumtionsbeteende. Detta beror troligen på diskrepansen mellan attityd och beteende där konsumenternas attityd inte reflekteras i deras faktiska konsumtionsbeteenden. Del 2 Produktion och konsumtion av livsmedel har en stor påverkan på miljön, primärt från jordbruket men även genom behandling av livsmedel, transporter och avfallshantering. En ökad medvetenhet hos konsumenter har resulterat i en ökad efterfrågan av transparens i produktionskedjan av livsmedel, och därmed ett ökat behov av kunskap gällande olika livsmedels miljöpåverkan. Genom att studera miljöpåverkan från produkten BäR smoothie från det finska företaget Toripiha är syftet med denna studie att identifiera delar i produktens produktionskedja som har en betydande miljöpåverkan, så kallade hotspots. För att studera miljöpåverkan från en flaska BäR smoothie á 250 ml utfördes en livscykelanalys (LCA) i enlighet med ISO-standarderna ISO 14040 och ISO 14044. Närmare bestämt utfördes en bokförings-LCA, vilket innebär att miljöpåverkan studeras utifrån produktens livscykel. De miljöpåverkanskategorier som inkluderades i studien var global uppvärmning, övergödning och primärenergianvändning, som mättes med kategoriindikatorerna koldioxidekvivalenter (CO2-ekv), fosfatekvivalenter (PO4-ekv) och megajoule (MJ). Den inventeringsdata som användes hämtades främst från databasen Ecoinvent version 3.7, men även från vetenskapliga artiklar och tidigare studier, samt från beräkningsverktyget NTMCalc Basic 4.0. Resultaten av denna studie belyser de delar i produktionskedjan för BÄR smoothie som har störst miljöpåverkan med avseende de valda miljöpåverkanskategorierna. En flaska BäR smoothie á 250 ml bidrog totalt med 120 g CO2-ekv, 0,39 g PO4-ekv och 2,8 MJ. Den komponent med störst miljöpåverkan med avseende på global uppvärmning och primär energianvändning och som även hade en betydande inverkan på övergödning var flaskan, dvs. produktion av PET-granulat (vPET) och återvunnen PET-granulat (rPET). Eftersom majoriteten av detta bidrag kom från produktionen av vPET-granulat, rekommenderades Toripiha att använda flaskor som har ett högre innehåll av rPET-granulat för att minska produktens totala miljöpåverkan. Det var också tydligt att transporten av komponenter stod för en betydande del av miljöpåverkan med avseende på samtliga miljöpåverkanskategorier. För att minska miljöpåverkan från transporter bör Toripiha därför sträva efter kortare och mer effektiva transporter för de olika komponenterna.

Ce travail se focalise sur l’étude de cellules solaires organiques modèles basées sur le mélange de poly(3-hexylthiophène) (P3HT) et de l'ester méthylique de l'acide [6,6]-phényl C61 butyrique (PCBM). La corrélation entre la morphologie de la couche active, les paramètres de mises en œuvre et le rendement photovoltaïque a été soigneusement étudiée afin d’obtenir l’optimisation de l’efficacité de tels dispositifs. Une méthode originale pour contrôler la séparation de phases dans ces mélanges a été proposée et consiste à l'intégration de copolymères blocs comme additifs. Trois copolymères séquencés ont été utilisés en tant qu’agents de nanostructuration et/ou d'agents de nucléation. Il a notamment été montré que l'incorporation de P3HT-b-PI permet l'augmentation du nombre de cristallites de P3HT tout en limitant l’agglomération du PCBM. D'autre part, l'incorporation de P3HT-b-P4VP dans les mélanges de P3HT:PCBM a permis de contrôler l'orientation des cristallites de P3HT, améliorant par ce fait le transport de charge dans les dispositifs. / This work investigates organic solar cells made of a blend of polymeric materials based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as model system. The correlation between the photovoltaic active layer morphology and the performance of the organic solar cell is thoroughly investigated. The chosen method for controlling phase separation in the polymeric blends is to incorporate block copolymers as additives. Three systematically selected block copolymers were used as nanostructuring and/or nucleating agents. Indeed, the incorporation of P3HT-b-PI induces the increase in the number of P3HT crystallites as well as suppresses the growth of PCBM aggregates. On the other hand, the incorporation of P3HT-b-P4VP into P3HT:PCBM decreases the crystallization of P3HT but increases its face-on orientation, a requirement for an enhanced charge transport in organic PV devices.

Multi-combination vehicles (MCVs) in urban areas impact on productivity, safety, infrastructure, congestion and the environment. However, psychological effects of MCVs on other drivers may also influence the positioning of vehicles and congestion. A literature review revealed little information on the psychological effects of heavy vehicles on other road users. This research can be used to quantify some psychological impacts of MCVs. A testing program was undertaken on the Gateway Motorway to observe passenger car behaviour around MCVs in a lateral and longitudinal sense. Video footage was collected on a four lane divided urban motorway section which was level, straight and away from any off/on ramps. It experiences high traffic volumes with a one-way AADT of approximately 33,500. The route is currently designated for B-doubles, which is the most common MCV in urban areas. In a lateral sense, the research showed that passenger car behaviour changes around heavy vehicles (prime mover semi-trailer combination and B-doubles); however, there is no statistical difference in passenger car behaviour around semi-trailers and B-doubles. Longitudinally it was found that, even though passenger cars shy away from B-doubles more than semi-trailers, B-doubles are still more efficient in a spatial sense since they carry more freight. The outcomes of this research indicate that there is no further psychological impact on passenger cars, when travelling around B-doubles compared with semi-trailers. Where the results identified longitudinal behaviour changes, it was still concluded that B-doubles were more efficient at transporting freight when the passenger car equivalent (PCE) per tonne of freight was considered. Tracking ability testing was undertaken in a rural area to determine the lateral spatial requirements of three different MCVs. The rural testing was considered appropriate since parts of the urban network have similar characteristics to rural networks. A model was developed as a part of this project to process the data collected by Haldane (2002), but results could not be relied upon due to poor quality data.

[pt] O presente trabalho tem como principal objetivo contribuir para a desmistificação da dinâmica atual do deflator do consumo americano.Com esta finalidade, é avaliada a evolução temporal da Curva de Phillips americana, utilizando como referência a especificação apresentada por Yellen (2015). Os resultados encontrados são analisados e comparados com novas estimativas para diferentes variáveis de núcleo de inflação, expectativa de inflação e ociosidade do mercado de trabalho. A hipótese de não linearidade da Curva de Phillips também é testada. Por fim, um modelo alternativo ao de referência é sugerido e o deflator do consumo é desagregado para uma melhor compreensão. Concluímos que a Curva de Phillips continua válida e que não houve achatamento ao longo dos anos 2000. Ademais, não foi constatado suporte estatístico para a hipótese de não linearidade. Com isso, os principais responsáveis identificados pelo caso da inflação perdida são categorias que sofreram choques estruturais relacionados aos seus respectivos setores. E se esta avaliação estiver correta e os choques setoriais forem persistentes, o banco central americano possivelmente precisará implementar uma posição mais acomodatícia do que seria apropriado para atingir sua meta de longo prazo. / [en] The purpose of this dissertation is to contribute to the demystification of the current dynamics of the inflation in United States.The Phillips Curve in the United States is evaluated since 1990s, using the model presented by Yellen (2015) as a reference. The results are analyzed and compared with new estimates for different core inflation variables, inflation expectations, and labor market slack. The nonlinearity hypothesis of the Phillips curve is also tested. Finally, an alternative to the model is suggested and the consumption price deflator is disaggregated.The results indicate that the Phillips Curve is still valid and that there was no flattening over the 2000s. In addition, no evidence of statistical significance was found for the nonlinearity hypothesis. Therefore, the main cause of the missed inflation are categories that suffered structural shocks related to their respective sectors. If this assessment is accurate and these sector-specific shocks continue, achieving the Federal Reserve s 2 percent inflation goal over the medium term may require a more accommodative stance of monetary policy than might otherwise be appropriate.

Abstract The releases of chlorinated volatile organic compounds (CVOCs) are controlled by strict regulations setting high demands for the abatement systems. Low temperature catalytic oxidation is a viable technology to economically destroy these often refractory emissions. Catalysts applied in the oxidation of CVOCs should be highly active and selective but also maintain a high resistance towards deactivation. In this study, a total of 33 different γ-Al2O3 containing metallic monoliths were studied in dichloromethane (DCM) and 25 of them in perchloroethylene (PCE) oxidation. The active compounds used were Pt, Pd, Rh or V2O5 alone or as mixtures. The catalysts were divided into three different testing sets: industrial, CVOC and research catalysts. ICP-OES, physisorption, chemisorption, XRD, UV-vis DRS, isotopic oxygen exchange, IC, NH3-TPD, H2-TPR and FESEM-EDS were used to characterise the catalysts. Screening of the industrial catalysts revealed that the addition of V2O5 improved the performance of the catalyst. DCM abatement was easily affected by the addition of VOC or water, but the effect on the PCE oxidation was only minor. Based on these screening tests, a set of CVOC catalysts were developed and installed into an industrial incinerator. The comparison between the laboratory and industrial scale studies showed that DCM oxidation in an industrial incinerator could be predicted relatively well. Instead, PCE was always seen to be oxidised far better in an industrial unit indicating that the transient oxidation conditions are beneficial for the PCE oxidation. Before starting the experiments with research catalysts, the water feed was optimised to 1.5 wt.%. Besides enhancing the HCl yields, water improved the DCM and PCE conversions. In the absence of oxygen, i.e. during destructive adsorption, the presence of water was seen to have an even more pronounced effect on the HCl formation and on the catalysts’ stability. In the DCM oxidation, the addition of the active compound on the catalyst support improved the selectivity, while the enhancing effect on the DCM conversion was only small. The high acidity together with the increased reducibility was seen to lead to an active catalyst. Among the research catalysts Pt/Al2O3 was the most active in the DCM oxidation. With PCE the addition of the active compound proved to be very beneficial also for the PCE conversion. Now Pt and Pd supported on Al2O3-CeO2 were the most active. The enhanced reducibility was seen to be the key feature of the catalyst in PCE oxidation. / Tiivistelmä Klooratuille orgaanisille hiilivedyille (CVOC) on asetettu tiukat päästörajoitukset niiden haitallisten vaikutusten takia. Tästä johtuen myös puhdistusmenetelmien tulee olla tehokkaita. Katalyyttinen puhdistus on teknologia, jolla nämä usein vaikeasti käsiteltävät yhdisteet voidaan taloudellisesti tuhota. Käytettävien katalyyttien tulee olla aktiivisia ja selektiivisiä sekä hyvin kestäviä. Tässä työssä tutkittiin yhteensä 33 erilaista γ-Al2O3-pohjaista hapetuskatalyyttiä metyleenikloridin (DCM) käsittelyssä, niistä 25 testattiin myös perkloorietyleenin (PCE) hapetuksessa. Aktiivisina metalleina katalyyteissä käytettiin platinaa, palladiumia, rhodiumia ja vanadiinia yksin tai seoksina. Katalyytit jaettiin kolmeen ryhmään: teolliset-, CVOC- ja tutkimuskatalyytit. Aktiivisuuskokeiden lisäksi katalyyttejä karakterisoitiin ICP-OES-, fysiorptio-, kemisorptio-, XRD-, UV-vis DRS-, isotooppivaihto-, IC-, NH3-TPD-, H2-TPR- ja FESEM-EDS-pintatutkimusmenetelmillä. Koetulokset osoittivat, että vanadiini paransi teollisuuskatalyyttien aktiivisuutta ja selektiivisyyttä. VOC-yhdisteen tai veden lisäys paransi DCM:n hapettumista, mutta PCE:n hapettumiseen niillä ei ollut vaikutusta. Testien perusteella kehitettiin CVOC-katalyytit, jotka asennettiin teolliseen polttolaitokseen. Laboratoriossa ja teollisuudessa tehdyissä testeissä havaittiin, että DCM:n hapettuminen oli laboratoriokokeiden perusteella ennustettavissa. Sen sijaan PCE hapettui teollisuudessa aina paljon paremmin kuin laboratorio-olosuhteissa. Tämä osoittaa, että muuttuvat hapettumisolosuhteet vaikuttivat positiivisesti PCE:n hapettumiseen. Veden määrä syöttövirrassa optimoitiin 1,5 %:iin ennen tutkimuskatalyyttien testausta. Selektiivisyyden lisäksi vesi paransi DCM:n ja PCE:n konversiota. Hapettomissa olosuhteissa, ts. tuhoavien adsorptiokokeiden aikana, vesi paransi reaktion selektiivisyyttä HCl:ksi ja CO2:ksi vielä entisestään. Tämän lisäksi vesi lisäsi katalyytin stabiilisuutta. DCM:n hapetuksessa aktiivisen metallin lisäys paransi selektiivisyyttä, mutta sen sijaan vaikutus DCM:n konversioon oli hyvin pieni. Tulokset osoittivat, että aktiivisella DCM:n hapetuskatalyytillä tulee olla korkea happamuus ja hyvä pelkistyvyys. Pt/Al2O3 oli testatuista tutkimuskatalyyteistä aktiivisin. PCE:n hapetuksessa aktiivisen metallin lisäys paransi selektiivisyyden lisäksi huomattavasti myös konversiota. Katalyytin lisääntyneen pelkistymiskyvyn todettiin olevan keskeisin ominaisuus PCE:n hapettumisessa. Pt/Al2O3-CeO2 ja Pd/Al2O3-CeO2 olivat tutkimuskatalyyteistä aktiivisimpia.

Cette thèse questionne les pratiques des enseignants et leur capacité à exploiter les appareils théoriques présentés durant leur formation à l’enseignement dans leur pratique quotidienne. L’objectif est d’analyser des « praxéologies » d’enseignement, au travers de l’étude de la transposition qui s’effectue dans le cas de la formation aux théories de « l’éducation centrée sur la résolution de problèmes (PCE) » vers les pratiques concrètes d’enseignement. Les parties théoriques s’emploient à définir la notion de « compétences à enseigner » ainsi que la notion de PCE. Le but ultime est de définir les compétences qui sont indispensables pour l’organisation de l’apprentissage dans le cadre de la PCE. La partie empirique étudie les praxéologies des enseignants qui travaillent avec la PCE. L’analyse des données permet de repérer dans les praxéologies des professeurs des éléments pertinents pour l’enseignement dans le cadre du modèle PCE qui représentent certains indicateurs de compétence. / The research addresses the problem of teaching competences and the transposition of certain theoretical understandings into teachers’ own practice.The aim is to study teaching praxeologies of teachers who learn to work with the Problem-Centred Education (PCE) in order to shed light into the question of how teachers construct their teaching competence in this domain.The theoretical part explores the concept of teaching competences in general and defines those relevant for the PCE in particular. The concept of the PCE is also defined and positioned among the existing ‘problem’ approaches. The aim is to outline teaching competences relevant for the PCE.The empirical part aims at studying teachers’ understanding and practical application of the Problem-Centred Education. The analysis allowed revealing certain essential components in teachers’ praxeologies that are assumed to serve as an indicator of a certain level of teaching competence in the domain of the PCE. A tentative relation between some components has also been suggested.

In recent years, IP based end-to-end services have grown in popularity. Efficiently meeting the user demand for such services, different techniques for traffic engineering transport networks have been developed. One such technique, currently being developed for multilayered networks, is Generalized Multi-Protocol Label Switching (GMPLS). GMPLS is a necessary networking technique because provisioning end-to-end services will today, and in the foreseeable future, very likely require the co-operation of multiple network layers. Here, the readiness of GMPLS for optical networks is investigated by reviewing the current support for optical networking components in the GMPLS standard documents. Based on this investigation, a candidate solution for routing and constraint-based path computation in optical network segments has been derived. This candidate solution is shown to efficiently handle the additional attributes and constraints inherent in optical networking components. / De senaste åren har IP-baserade tjänster ökat i popularitet. För att effektivt möta de användarkrav som ställs på sådana tjänster har olika tekniker för att styra transportnätverk utvecklats. En sådan teknik, nu under utveckling för multi-lagrade nätverk, är GMPLS. GMPLS är en nödvändig nätverksteknik eftersom tillhandahållandet av sluttjänster mellan olika användare idag, och inom en överskådlig framtid, mycket sannolikt kommer att kräva samarbete mellan flera nätverkslager. Här undersöks GMPLS färdighet i optiska nätverk genom att se över det nuvarande stödet för optiska nätverkskomponenter i GMPLS standarddokument. Baserat på denna undersökning har en kandidatlösning för routing och begränsad vägberäkning i optiska nätverkssegment tagits fram. Denna kandidatlösning visas effektivt hantera de ytterligare attribut och restriktioner som existerar i optiska nätverkskomponenter.

<p dir="ltr">Transitioning to a carbon-neutral future will require a broad portfolio of green energy generation and storage solutions. With the abundant availability of solar radiation across the Earth’s surface, energy generation from photovoltaics (PVs) will be an important part of this green energy portfolio. While silicon-based solar cells currently dominate the PV market, temperatures exceeding 1000 °C are needed for purification of silicon, and batch processing of silicon wafers limits how rapidly Si-based PV can be deployed. Furthermore, silicon’s indirect band gap necessitates absorber layers to exceed 100 µm thick, limiting its applications to rigid substrates.</p><p dir="ltr">Solution processed thin-film solar cells may allow for the realization of continuous, high-throughput manufacturing of PV modules. Thin-film absorber materials have direct band gaps, allowing them to absorb light more efficiently, and thus, they can be as thin as a few hundred nanometers and can be deposited on flexible substrates. Solution deposition of these absorber materials utilizing molecular precursor-based inks could be done in a roll-to-roll format, drastically increasing the throughput of PV manufacturing, and reducing installation costs. In this dissertation, solution processed synthesis and the characterization of two emerging direct band gap absorber materials consisting of earth abundant elements is discussed: the enargite phase of Cu₃AsS₄ and the distorted perovskite phase of BaZrS₃.</p><p dir="ltr">The enargite phase of Cu₃AsS₄ (ENG) is an emerging PV material with a 1.42 eV band gap, making it an ideal single-junction absorber material for photovoltaic applications. Unfortunately, ENG-based PV devices have historically been shown to have low power conversion efficiencies, potentially due to defects in the material. A combined computational and experimental study was completed where DFT-based calculations from collaborators were used inform synthesis strategies to improve the defect properties of ENG utilizing new synthesis techniques, including silver alloying, to reduce the density of harmful defects.</p><p dir="ltr">Chalcogenide perovskites are viewed as a stable alternative to halide perovskites, with BaZrS₃ being the most widely studied. With a band gap of 1.8 eV, BaZrS₃ could be an excellent wide-bandgap partner for a silicon-based tandem solar cell.Historically, sputtering, and solid-state approaches have been used to synthesize chalcogenide perovskites, but these methods require synthesis temperatures exceeding 800 °C, making them incompatible with the glass substrates and rear-contact layers required to create a PV device. In this dissertation, these high synthesis temperatures are bypassed through the development of a solution-processed deposition technique.A unique chemistry was developed to create fully soluble molecular precursor inks consisting of alkaline earth metal dithiocarboxylates and transition metal dithiocarbamates for direct-to-substrate synthesis of BaZrS₃ and BaHfS₃ at temperatures below 600 °C.</p><p dir="ltr">However, many challenges must be overcome before chalcogenide perovskites can be used for the creation of photovoltaic devices including oxide and Ruddlesden-Popper secondary phases, isolated grain growth, and deep level defects. Nevertheless, the development of a moderate temperature solution-based synthesis route makes chalcogenide perovskite research accessible to labs which do not have high temperature furnaces or sputtering equipment, further increasing research interest in this quickly developing absorber material.</p>

Made available in DSpace on 2016-03-15T19:36:54Z (GMT). No. of bitstreams: 1 Maria Claudia Lopes Guerra.pdf: 9968717 bytes, checksum: 7d0e4986884ffa382a835b641ed76573 (MD5) Previous issue date: 2015-06-12 / Fundo Mackenzie de Pesquisa / The ECAP (Equal Channel Angular Pressing) is a mechanical process of Severe Plastic Deformation (SPD) where a sample is subjected to a shearing force when passing through the region of intersection of two channels. The main goal of this method is Severe Plastic Deformation achieve a microstructure with ultrafine grains, which have much higher than the equivalent coarse grain materials physical properties, such as an increase in strength and toughness simultaneously. What makes this increasingly interesting technique is that as there is no reduction cross section is possible to obtain plastic strain accumulation and therefore gain in grain order of nanometer scale. The great advantage of ECAP is to achieve a much higher degree of strain hardening than obtained by conventional methods of plastic deformation, and consequently a grain refining much higher as well. The importance of the study of severe plastic deformation process is on improving the mechanical performance of the materials and the possibility of a better understanding of the mechanisms of strain hardening, which may indicate a new path for producing high-strength materials, possibly scaled industrial. In this work are presented the microstructural, mechanical and electrical analysis of the aluminum alloy AA 1050 samples, commonly used for electrical purposes, with ultrafine grains (typical grain size below a micron) resulting from processing by ECAP, based on the method of SPD. / A PCE (Prensagem em Canais Equiangulares) consiste num processo mecânico de Deformação Plástica Intensa (DPI) onde um corpo de prova é sujeito a um esforço de cisalhamento ao passar pela região de intersecção de dois canais. Os principais objetivos desse método de Deformação Plástica Intensa é alcançar uma microestrutura com grãos ultrafinos, os quais possuem propriedades físicas muito superiores aos equivalentes materiais de grãos grosseiros, como um aumento em resistência mecânica e tenacidade simultâneas. O que torna esta técnica cada vez mais interessante é que como não há redução da seção transversal é possível obter acumulo de deformação plástica e com isso obter grãos na ordem de escala nanométrica. A grande vantagem do PCE é alcançar um grau de encruamento muito superior do que obtido por métodos convencionais de deformação plástica, e consequentemente, um refino de grão muito superior também. A importância do estudo do processo de deformação plástica intensa está na melhoria do desempenho mecânico dos materiais e na possibilidade de uma melhor compreensão dos mecanismos de encruamento, fato que pode indicar um novo caminho para a produção de materiais de alta resistência mecânica, possivelmente em escala industrial. Nesse trabalho são apresentadas as análises microestruturais, mecânicas e elétricas de amostras de ligas de alumínio AA 1050, comumente utilizadas para fins elétricos, com estrutura de grãos ultrafinos (tamanho de grão típico abaixo de um micrometro) resultantes do processamento por PCE, baseada no método de DPI.