The use of full-depth precast concrete bridge deck panels is becoming more and more attractive to transportation authorities throughout the country. In comparison to conventional cast-in-place decks, precast decks are of higher quality, allow for the bridge to be opened to traffic in less time and are easier to maintain, rehabilitate, and replace. This ultimately results in lower costs for transportation authorities and less disruption for the motoring public. Unfortunately, the use of precast deck panel systems is hindered by the lack of design standardization and information regarding the performance of such systems. This research focuses on a key element of the system, the mortar or grout, which is used to connect the precast panels to the bridge girders by filling the space in the horizontal shear pockets and the haunches. Several essential mortar characteristics were identified and investigated in order to create a specification that indicates required performance criteria for mortars. This specification can be used to determine whether particular mortars or grouts are suitable for use in a full-depth precast concrete bridge deck panel system. / Master of Science

La mobilité économique est une des aspirations de toute société moderne, mais comment peut-on savoir la véritable évolution de la mobilité sociale ? C’est-à-dire : 1) peut-on mesurer la mobilité sociale avec les données ou la technologie disponibles aujourd’hui? 2) Quelles sont les tendances de la mobilité sociale qui a traversées la génération actuelle? Ou encore 3) à quel point la société actuelle est-elle mobile par rapport aux anciennes générations? Ce sont les trois questions à la base de cette thèse. Nous soutenons ici que c’est possible de connaître encore plus sur l’évolution de la mobilité sociale en restreignant son analyse à quelques dimensions dans le champ de l’économie : le revenu et l’éducation. Le première article s’attaque au problème du manque des données nécessaires pour l’analyse des dynamiques du revenu à l’intérieur d’une génération. Il est avéré que les données longitudinales sont rares et très peu disponibles dans la plupart des pays, ce qui est vrai même pour les pays développés ! Nous avons essayé d’assembler ce casse-tête par des approches méthodologiques récentes, telles que les «panels synthétiques», une méthodologie normalement utilisée pour l’analyse des dynamiques de la pauvreté. Les articles deux et trois décrivent, plus spécifiquement, les tendances à long terme de la mobilité économique pour le revenu et pour l’éducation, respectivement. Le deuxième papier s’occupe de la mobilité intra-générationnelle, tandis que le troisième est dédié à la mobilité intergénérationnelle. Tous les deux répondent aux questions deux et trois posées plus en haut, en cherchant d’améliorer la façon dont la dimension temporaire est incluse dans l’analyse du bien-être économique, ceci avec pour but de reproduire l’effet d’un film fait avec plusieurs clichés. Cette thèse cherche à élargir le savoir expérimental sur la mobilité économique, vu que la plupart des études ne prennent en compte que quelques années de mobilité intra-générationnelle ou à peine quelque génération. En outre, la plupart des résultats des expériences existantes font référence aux pays scandinaves ou à des pays fortement industrialisés. Pour cette thèse nous avons donc pris l’exemple du Mexique, mais les approches et les principes méthodologiques utilisés pourront être appliqués à n’importe quel autre pays. Les chemins de nos vies sont dans un mouvement perpétuel : par monts et par vaux. Dans une société démocratique, il semble utile de savoir si notre appartenance sociale nous permet de nous en sortir malgré nos origines, ou si au contraire, notre destin est voué à l’échec à cause d’elles. Il nous faut en effet, des résultats empiriques pour répondre à ces délibérations. Cette thèse est peut-être une invitation osée à mettre en marche cette conversation. / Economic mobility constitutes a social aspiration in many modern societies however do we really know the actual evolution of social mobility? In other words: 1) how can we measure economic mobility with the data available or with the technology at hand? 2) What are the trends of economic mobility experienced by the current generation? Moreover 3) how mobile is a society relative to previous generations? These questions motivate this dissertation. The complexity of these issues may derive in some sort of paralysis but it is claimed here that it may be possible to learn something about its evolution by restricting analysis to a couple of key dimensions within the economic discipline: income and education. This is the scope followed by this research. The first paper in this dissertation is devoted to deal with the lack of the required data to examine the income dynamics within one generation. It is well known that longitudinal data is often scarce and is seldom available in many countries. This is the case even in well-developed countries! This conundrum has been partially addressed through recent methodological approaches by the so-called synthetic panels. The second part of this dissertation is entirely devoted to applied research. More specifically, the second and third papers describe long run trends of economic mobility in income and education respectively. The former is devoted to intra-generational mobility while the later is devoted to inter-generational mobility. Each of them address the second and third interrogations referred above. In a way this dissertation attempts to improve the addition of the time dimension in the analysis of economic wellbeing. It attempts to produce the effect of a motion picture by the use multiple snapshots. The trends contained herein are far from being perfect and complete but they are based on the use of extensive data and multiple methods covering three decades and the same number of generations in each case. This research expects to expand our knowledge on the empirics of economic mobility as most of the studies refer to few years of intra-generational mobility or to a couple of generations only. Furthermore, most of the empirical evidence available refers to Nordic and highly industrialized countries. Mexico is the canvas of this work but the approaches and principles followed here could be easily mimicked elsewhere. The roads of our lives are constantly moving: rising and falling. In a democratic context, it is useful to know, whether our society provides the chance to get ahead regardless of our origins, or whether this chance is ruled or doomed by them. Empirical evidence is needed to foster these deliberations. This dissertation may well be an invitation to sustain this kind conversation.

No description available.

Denna rapport täcker framtagandet av en prototyp för ett ramverk av soft front panels för testutrustning hos Saab Support and Services [1]. Prototypen ska användas av Saab i en utvärdering rörande en möjlig implementation och nyttan av ett sådant ramverk i Saabs befintliga system. Under framtagandet av prototypen har även en utredning rörande möjligheterna och problemen med att använda WiFi i känsliga miljöer utförts. Denna utredning är kopplad till prototypen i den mening att det finns ambition från Saab att använda liknande system trådlöst. Prototypen är även framtagen för att stödja WiFi som medel för kommunikation med den utrustning den är kopplad mot. Efter en utvärdering av olika ramverk valdes WPF som ramverk för framtagandet av prototypen. Programmeringen skedde i programmeringsspråket C# och XAML. Prototypen kopplades initialt upp mot simulerade instrument, för att ge ökad flexibilitet under utvecklingen. Den färdiga prototypen testades med faktiskt hårdvara tillsammans med simulerade PXI-moduler och uppvisade ett gott resultat. Fördjupningen angående användningen av WiFi i känsliga miljöer resulterade i ett antal förslag på åtgärder för att motverka störningar och signalläckage, så som användningen av WiFi-protokoll med höga frekvensband och ”defensive jamming”. / This report covers the creation of a prototype for a framework of soft front panels for test equipment at Saab Support and Services [1]. The prototype will be used by Saab in an evaluation regarding the possible implementation and benefits of such a framework in Saabs current system. During the creation of the prototype there has been an in-depth look at the possibilities and problems regarding the use of WiFi in sensitive environments. This in-depth look is tied to the prototype in such a way that there is an ambition at Saab of utilizing similar systems wirelessly. The prototype has been created in such a way that it supports WiFi as means of communication with the equipment it is connected to. After an evaluation of different frameworks WPF was chosen for the development of the prototype. The programming was done in the programming language C# and XAML. The prototype was initially connected to a set of simulated instruments, for increased flexibility during the development. The completed prototype was tested with actual hardware together with simulated PXI-modules and the results where satisfactory. The in-depth look regarding the use of WiFi in sensitive environments resulted in a number of suggestions for actions to counter interference and leakage of signals, such as the use of WiFi-protocols using a high frequency band and ”defensive jamming”.

The research proposed consists in providing a climatic file of received radiation together with solar electric generation for a 1.17 kWp PV system in the city of Gävle. In addition, both radiation and solar electric generation will be compared making use of the WINSUN program. Possible disparities between both data have been analyzed. The interest of this study lies in the lack of a file that provides radiation data in the city of Gävle, which may be of help to people interested in making some kind of photovoltaic installation. Similar studies have been carried out previously in different locations which have tested different models to evaluate various climatic factors affecting the performance of the panels. The research method has been a case study in which monocrystalline solar panels installed in building 45 of the University of Gävle (HiG) have been analyzed together with the radiation data provided by three pyranometers. The results exhibit the importance of adjusting parameters such as diffuse coefficient, horizontal shading, and system efficiency. Results of this study show an accurate climate file, with little errors between measured and simulated data, with values of global performance indicator (GPI) (-2.70E-10, -1.06E-12) for 2022 and 2023 respectively.

This term paper deals about history, principle and use of photovoltaic panel. It describes their stucture and constantly improving properties of these panels. It outlines their gradual generational evolution from beginning to present. Then it describes the various systems involved on – grid and off – grid. It also describes and compares the photovoltaic panels and inverters from different global manufacturer. The end of this work deals about conditions of photovoltaic in the Czech republic and about Hady photovoltaic incubator, which belongs to the company Energ servis a.s. It presents a comparison of different local and the analysis of the impact of shading for the achievement of the photovoltaic panel. It makes mathematic models for calculation of the spacing range and calculation the power loss in a specific shade.

Abstract Photovoltaic (PV) solar panels are solar energy collection systems with increasing terrestrial and roof applications reported worldwide. If the terrestrial mounting does not require specific wind resistance verifications, installing them on top of flat and gable roofs implies a drastic change of the roofing systems geometry, thus a re-evaluation of the wind-induced pressure is necessary. Among the roof top applications, provisions exist for the flat roofs mounted solar panels, however, design recommendations for wind-induced loadings on PV solar panels arrays flush-mounted on gable roofs are not fully developed in current wind loading standards (SEAOC PV2-2012) and building codes (ASCE 07, NBCC 2015), in spite of the numerous applications on residential and agricultural buildings, primarily due to the limited research investigating this topic. The current dissertation employs CFD k-ɛ and LE (Large Eddy) simulations for analyzing the effects of wind acting on solar panels flush-mounted on gable roofs, considering the influence of several parameters such as: the slope of the gable roof, the wind directions, the spaces between the adjacent solar panel arrays and the clearance between the roof surface and the solar panels. A comprehensive database of solar panels with different installation parameters subjected to wind speeds were developed under the current research project. The database includes detailed distribution of wind-induced pressure coefficients for the three parallel surfaces constituting the roof-solar panels systems: the top and bottom surfaces of the panels, and the roof surface under the panels, which represents a novel approach in investigating and clarifying the wind effects on solar panels. This approach also provides in detail the variation of the pressure coefficients on the three surfaces, due to the change of installation conditions (roof slope, arrays spacing, roof clearance) and wind parameters (wind speed and wind direction). As an original contribution to the existing knowledge, this thesis found that the installation of solar arrays on gable roofs, redistributes the wind-induced pressure on both sides of the roof windward and leeward, resulting in total horizontal wind-induced pressures on the entire roof lower than that registered on the corresponding roof without solar panels. In addition, dominant resultant pressure coefficients on solar panels concluded to be lower than for the roof without panels. When the roof clearance increases, total average pressure coefficients on the roof supporting the panels decreases on both, windward and leeward sides of the roof. Moreover, when the roof clearance increases, the pressures in the cavity decrease significantly on both windward and leeward sides of the roof, which could impact the requirements for installing and fixing such panels on gable roofs. For example, for 10” clearance the flush-mounted solar panels were subject to pressure instead of suction. Similarly, when panel array spacing increases, the magnitude of the net mean pressure coefficients on the roof surface under the solar panels further decreases for all wind directions investigated.

In aerospace applications, use of laminates made of composite materials as face sheets in sandwich panels are on the rise. These composite laminates have low transverse shear and transverse normal moduli compared to the in-plane moduli. It is also seen that the corresponding transverse strength values are very low compared to the in-plane strength leading to delaminations. Further, in sandwich structures, the core is subjected to significant transverse shear stresses. Therefore the interlaminar stresses (i.e., transverse shear and normal) can govern the design of sandwich structures. As a consequence, the first step in achieving efficient designs is to develop the ability to reliably estimate interlaminar stresses. Stress analysis of the composite sandwich structures can be carried out using 3-D finite elements for each layer. Owing to the enormous computational time and resource requirements for such a model, this process of analysis is rendered inefficient. On the other hand, existing plate/shell finite elements, when appropriately chosen, can help quickly predict the 2-D displacements with reasonable accuracy. However, their ability to calculate the thickness-wise distributions of interlaminar shear and normal stresses and 3-D displacements remains as a research goal. Frequently, incremental refinements are offered over existing solutions. In this scenario, an asymptotically correct dimensional reduction from 3-D to 2-D, if possible, would serve to benchmark any ongoing research. The employment of a mathematical technique called the Variational Asymptotic Method (VAM) ensures the asymptotical correctness for this purpose. In plates and sandwich structures, it is typically possible to identify (purely from the defined material distributions and geometry) certain parameters as small compared to others. These characteristics are invoked by VAM to derive an asymptotically correct theory. Hence, the 3-D problem of plates is automatically decomposed into two separate problems (namely 1-D+2-D), which then exchange relevant information between each other in both ways. The through-the-thickness analysis of the plate, which is a 1-D analysis, provides asymptotic closed form solutions for the 2-D stiffness as well as the recovery relations (3-D warping field and displacements in terms of standard plate variables). This is followed by a 2-D plate analysis using the results of the 1-D analysis. Finally, the recovery relations regenerate all the required 3-D results. Thus, this method of developing reduced models involves neither ad hoc kinematic assumptions nor any need for shear correction factors as post-processing or curve-fitting measures. The results are most general and can be made as accurate as desired, while the procedure is computationally efficient. In the present work, an asymptotically correct plate theory is formulated for composite sandwich structures. In developing this theory, in addition to the small parameters (such as small strains, small thickness-to-wavelength ratios etc.,) pertaining to the general plate theory, additional small parameters characterizing (and specific to) sandwich structures (viz., smallness of the thickness of facial layers com-pared to that of the core and smallness of elastic material stiffness of the core in relation to that of the facesheets) are used in the formulation. The present approach also satisfies the interlaminar displacement continuity and transverse equilibrium requirements as demanded by the exact 3-D formulation. Based on the derived theory, numerical codes are developed in-house. The results are obtained for a typical sandwich panel subjected to mechanical loading. The 3-D displacements, inter-laminar normal and shear stress distributions are obtained. The results are compared with 3-D elasticity solutions as well as with the results obtained using 3-D finite elements in MSC NASTRAN®. The results show good agreement in spite of the major reduction in computational effort. The formulation is then extended for thermo-elastic deformations of a sandwich panel. This thesis is organized chronologically in terms of the objectives accomplished during the current research. The thesis is organized into six chapters. A brief organization of the thesis is presented below. Chapter-1 briefly reviews the motivation for the stress analysis of sandwich structures with composite facesheets. It provides a literature survey on the stress analysis of composite laminates and sandwich plate structures. The drawbacks of the existing anlaytical approaches as opposed to that of the VAM are brought out. Finally, it concludes by listing the main contributions of this research. Chapter-2 is dedicated to an overview of the 3-D elasticity formulation of composite sandwich structures. It starts with the 3-D description of a material point on a structural plate in the undeformed and deformed configurations. Further, the development of the associated 3-D strain field is also described. It ends with the formulation of the potential energy of the sandwich plate structure. Chapter-3 develops the asymptotically correct theory for composite sandwich plate structure. The mathematical description of VAM and the procedure involved in developing the dimensionally reduciable structural models from 3-D elasticity functional is first described. The 1-D through-the-thickness analysis procedure followed in developing the 2-D plate model of the composite sandwich structure is then presented. Finally, the recovery relations (which are one of the important results from 1-D through-the-thickness analysis) to extract 3-D responses of the structure are obtained. The developed formulation is applied to various problems listed in chapter 4. The first section of this chapter presents the validation study of the present formulation with available 3-D elasticity solutions. Here, composite sandwich plates for various length to depth ratios are correlated with available 3-D elasticity solutions as given in [23]. Lastly, the distributions of 3-D strains, stresses and displacements along the thickness for various loadings of a typical sandwich plate structure are correlated with corresponding solutions using well established 3-D finite elements of MSC NASTRAN® commerical FE software. The developed and validated formulation of composite sandwich structure for mechanical loading is extended for thermo-elastic deformations. The first sections of this chapter describes the seamless inclusion of thermo-elastic strains into the 3-D elasticity formulation. This is followed by the 1-D through-the-thickness analysis in developing the 2-D plate model. Finally, it concludes with the validation of the present formulation for a very general thermal loading (having variation in all the three co-ordinate axes) by correlating the results from the present theory with that of the corresponding solutions of 3-D finite elements of MSC NASTRAN® FE commercial software. Chapter-6 summarises the conclusions of this thesis and recommendations for future work.

Antal installerade solcellsanläggningar har ökat drastiskt de senaste åren i Sverige, och utsikten för ökad mängd solel i Sverige är mycket god, med prognoser på kraftig tillväxt av installerade solcellsanläggningar de kommande åren. Detta med bakgrund att utvecklingen av solcellspaneler har gjort att priset har sjunkit, samt politiska beslut har gjort det lönsamt att investera i solcellsanläggningar i Sverige. Dessa förutsättningar har lagt grunden för en ny växande bransch, solcellsinstallationer. Risken vid en ny och snabbt växande bransch är att kunskapen inom ämnet för de som är verksamma inom branschen kan vara bristfällig samt oseriösa företag kan lockas av att tjäna snabba pengar på en lukrativ marknad. Efter en omfattande litteraturstudie visades att någon större kvalitésundersökning av solcellsinstallationer i Sverige, med avseende på hållfasthet ej har gjorts tidigare. Detta motiverade att denna undersökning var av hög relevans. Syftet med denna studie var att ta reda på om solcellsanläggningar monteras tillräckligt hållfast i Gävle-Dalaregionen med avseende på snö- och vindlast. Fjorton anläggningar har besökts för att samla in data. Data har sedan utvärderats i tre kategorier per anläggning. För att en anläggning skall bedömas som en godkänd skall alla dessa tre kategorier vara godkända. Bedömningen av solcellsanläggningarna gjordes i de tre kategorierna: 1. montagesystemets antal infästningar, 2. mått mellan infästningarna, 3. placering av solcellspanelerna i förhållande till montagesystemet. Resultatet visade att ingen av dessa anläggningar var godkända i samtliga tre kategorier. Vissa anläggningar var godkända i två av tre kategorier, medan två anläggningar var ej godkänd i någon kategori. Vid en summering av bedömningsresultatet för alla anläggningar i de tre montagekategorierna, visades att ca 20% ej gick att fastställa (pga. bristande information) ca 40% var godkända och ca 40% var ej godkända. Bedömningar har gjorts utifrån beräkningsprogram och anvisningar tillhandahållna av tillverkarna av de montagesystem och solcellspaneler som har använts i anläggningarna. Att ingen anläggning var godkänd i samtliga tre kategorier som undersöktes indikerar att solcellsmontage på tegeltak byggs ej tillräckligt hållfast i Gävle-Dalaregionen. Detta kan dock inte generaliseras för solcellsanläggningar på tegeltak i hela Sverige då mängden undersökta anläggningar var relativt liten och endast fördelade på två län i landet. Då det antas att installatörer avser att bygga korrekta anläggningar visar denna studie att kunskap om solcellsmontage med avseende på hållfasthet är bristfällig. Detta kan vara en följd av den stora efterfrågan på solcellsinstallationer, som kan medföra att stort fokus ligger på att installera anläggningar snabbt, och inhämtning av kunskap ej blir prioriterat. / The number of installed PV-systems (Photovoltaic systems) has increased rapidly in Sweden the last years, and the forecast for even more installations shows an increase for the coming years. Due to the price for PV-panels har dropped and political decisions for subventions of PV-systems has made it more profitable to invest in PV-installations in Sweden. These reasons have paved the road for a new growing branch, PV-installations. The risk of a new profitable, fast growing branch is that there might be short of knowledge for new installers, and the possibility that dishonest companies just want to take the advantage of the situation to make quick money, which can lead to installations poorly made.   After a search of published literature in strength of mounting for PV-panels there the result was that this is a rather unexplored subject, which motivated this investigation.   The aim of this study was to find out if PV-panels on tiled roofs were installed correct due to the snow load and wind load in the region Dalarna and Gävleborg in Sweden.   Fourteen PV-systems has been studied and evaluated. When the evaluation of the PV-systems were made the following criteria were considered: number of fixing attached to the roof of the mounting, distance between mounting fixings and how the PV-panels were installed relative the construction of the mounting. A PV-system had to be installed correctly for all three criterias to be considered approved. The result of this work shows that none of the evaluated systems were installed correctly. Some systems were approved in two of the criteria, while two systems were not approved in any of the criteria. The evaluation was made due to calculation programs and instructions from the manufacturers of mounting and PV-panels.   The fact that none of the PV-systems were approved for all three criteria implies that the installations of PV-systems are not made strong enough. This result is not stated for all installations in Sweden because the number of studied PV-systems were not big enough, and the area of the studied installations were rather small. Basis of snow load and wind load variates quite much in Sweden depending on region. It is assumed that designers and constructors attempt to install PV-systems correct, therefor shows this work that there’s a lack of knowledge for construct installations strong enough. This may be a result of the fast increase of PV-installations, where the priority lays in installing many PV-systems, not in education and search of knowledge.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Soils conditions vary throughout the United States and effect the behavior of the foundation system for building structures. The structural engineer needs to design a foundation system for a superstructure that is compatible with the soil conditions present at the site. Foundation systems can be classified as shallow and deep, and behave differently with different soils. Shallow foundation systems are typically used on sites with stiff soils, such as compacted sands or firm silts. Deep foundation systems are typically used on sites with soft soils, such as loose sands and expansive clays. A parametric study is performed within this report analyzing tilt-up concrete structures in Dallas, Texas, Denver, Colorado, and Kansas City, Missouri to determine the most economical tilt-up wall panel and foundation support system. These three locations represent a broad region within the Midwest of low-seismic activity, enabling the use of Ordinary Precast Wall Panels for the lateral force resisting system. Tilt-up wall panels are slender load-bearing walls constructed of reinforced concrete, cast on site, and lifted into their final position. Both a 32 ft (9.75 m) and 40 ft (12 m) tilt-up wall panel height are designed on three foundation systems: spread footings, continuous footings, and drilled piers. These two wall heights are typical for single-story or two-story structures and industrial warehouse projects. Spread footings and continuous footings are shallow foundation systems and drilled piers are a deep foundation system. Dallas and Denver both have vast presence of expansive soils while Kansas City has more abundant stiff soils. The analysis procedure used for the design of the tilt-up wall panels is the Alternative Design of Slender Walls in the American Concrete Institute standard ACI 318-05 Building Code and Commentary Section 14.8. Tilt-up wall panel design is typically controlled by lateral instability as a result from lateral loads combining with the axial loads to produce secondary moments. The provisions in the Alternative Design of Slender Walls consider progressive collapse of the wall panel from the increased deflection resulting from the secondary moments. Each tilt-up wall panel type studied is designed in each of the three locations on each foundation system type and the most economical section is recommended.