O atrativo estético proporcionado pela forma arredondada é o fator que na maioria das vezes determina a utilização de estruturas tubulares circulares. É crescente a concepção de pórticos formados por colunas tubulares e as tradicionais vigas de seção I. Esse tipo de ligação ainda é pouco estudado no Brasil, e esse trabalho busca avançar no entendimento do comportamento estrutural dessas ligações. Foram realizados estudos analíticos, numéricos e experimentais em quatro configurações de ligação, com diafragmas externos transversais, chapa de alma, soldas, parafusos e enrijecedor. Avaliou-se a relação M-\'fi\' (momento-rotação) das ligações estudadas e os parâmetros envolvidos como resistência, rigidez e ductilidade, evidenciando-se o modo de colapso das ligações. O estudo analítico foi desenvolvido baseado nas recomendações do Eurocode 3 (2005), com a utilização do Método das Componentes. A análise numérica, através do Método dos Elementos Finitos, foi realizada por meio dos programas computacionais TRUEGRID® e ANSYS®. Os modelos numéricos consideram as características mecânicas do aço, como plastificação, encruamento e não-linearidades geométricas e de contato. As formulações do Eurocode 3 (2005), adaptadas para a determinação da resistência das ligações viga-coluna, apresentaram resultados coerentes e a análise numérica foi representativa frente aos resultados experimentais. A utilização de diafragmas externos conectados à viga apresentou boa funcionalidade, ajudando na distribuição das tensões na região da ligação, melhorando o comportamento da coluna. / The aesthetic appeal provided by the round shape is the factor that mostly determines the use of circular tubular structures. There is an increasing conception of structures formed by hollow columns and traditional beams of section I. This type of connection hasn\' t been sufficiently studied in Brazil, and this paper tries to advance the comprehension of the structural behavior of these connections. Analytical, numerical, and experimental study were performed in four connections configurations, with transverse external diaphragms, web plate, welds, bolts and stiffener. The relation M-\'fi\' (moment-rotation) of the studied connections and the parameters involved such as strength, stiffness and ductility were evaluated, evidencing the failure mode of connections. The analytical study was developed based on recommendations of Eurocode 3 (2005) using the Method of Components. The numerical analysis using the Finite Element Method was performed with the computer programs TRUEGRID® and ANSYS®. The numerical models consider the mechanical characteristics of steel, such as yielding and hardening, and also the geometric and contact nonlinearity. The formulations of Eurocode 3 (2005), adapted for determining the strength of beam-column connections, showed coherent results and the numerical analysis was representative compared to experimental results. The use of external diaphragm connected to the beam showed good functionality, helping in the distribution of stress in the region of connection, improving the behavior of the column.

Este trabalho apresenta uma análise teórico-experimental do comportamento de juntas de argamassa solicitadas à compressão, usando para preenchimento da junta materiais comercialmente disponíveis e almofada de apoio de argamassa flexível, com o objetivo de propor recomendações de projeto que caracterizem a deformabilidade e a resistência da junta, visando um melhor aproveitamento da capacidade resistente do sistema pré-moldado. Inicialmente foi feito um levantamento bibliográfico sobre os principais parâmetros que influenciam o comportamento da junta e, posteriormente, foram realizadas algumas simulações numéricas utilizando-se o programa ANSYS 5.5.1. Em seguida, desenvolveu-se um programa experimental cujas variáveis foram: a espessura da camada de argamassa, a resistência do elemento pré-moldado e da argamassa, o material de preenchimento da junta, a presença de armadura de reforço na região adjacente à ligação e a rugosidade na superfície do elemento. Os resultados obtidos mostraram que a espessura de 20mm seria a mais indicada, pois, além de minimizar o efeito de descontinuidade provocado pela presença da junta, melhora o controle da uniformidade da espessura e o aparecimento de vazios. Observou-se também que o uso de concreto de alta resistência no elemento pré-moldado faz com que as tensões de fendilhamento tenham maior importância. Para um maior aproveitamento da capacidade resistente do sistema, o material de preenchimento também deve ser de alta resistência. Dos diversos materiais usados para o preenchimento da junta, a argamassa do tipo “Dry Pack" foi a que ofereceu melhores condições de execução. Além de proporcionar total aproveitamento da capacidade resistente do sistema, diminuiu a deformabilidade da junta e, conseqüentemente, a fissuração / In this thesis a theoretical-experimental analysis of the compression mortar joints behavior is presented. The joints were produced with commercially available materials and flexible support cushion. The purpose of this research was to obtain design recommendations that characterize the deformability and the strength of the joints, in order to have a better use of the precast system bearing capacity. Previous studies of this problem showed the main parameters related to the joint behavior and numerical simulations were carried out using ANSYS 5.5.1. An experimental program was developed considering as variables the thickness of the mortar layer, the strength of the precast concrete element and of the mortar, the joint material, the additional reinforcement in the connection area and the roughness of the element surface. The results showed that a 20mm thickness is most suitable, because besides minimizing the discontinuity effects, it improves the control of the uniformity of the thickness as well as the air retained in the joint. It was also observed that using high strength concrete precast elements the splitting stresses becomes more important. For a larger use of the bearing capacity of the system, the joint material should also be of high strength. The use of a "Dry Pack" mortar offered better execution conditions, improving the bearing capacity of the system, with less deformability as well as cracking

Recent studies showed the need for timber connections with high fire performance. Connections of members in timber structures commonly comprise steel connectors, such as dowels, screws, nails and toothed plates. However, multiple studies have shown that the presence of exposed metal in timber connections leads to a poor performance under fire conditions. Replacing metallic fasteners with non-metallic fasteners potentially enhances the fire performance of timber connections. Previous studies showed that Glass Fibre Reinforced Polymer (GFRP) dowels can be a viable replacement for steel dowels and that Densified Veneer Wood functions well as a flitch plate material. However, as the resin matrix of GFRP dowels is viscoelastic, connection creep, which is not studied before, can be of concern. Also no research has been carried out on the fire performance of these connections. Therefore, a study of the creep behaviour and the fire performance of non-metallic timber connections comprising GFRP dowels and a Densified Veneer Wood flitch plate was performed, as is discussed in this thesis. Predictive models were proposed to determine the connection slip and load bearing capacity at ambient and elevated temperatures and in a fire. The material properties and heat transfer properties required for these models were determined experimentally and predictions of these models were experimentally validated. Furthermore, an adjustment of the predictive model of connection slip at ambient temperature allowed approximating the creep of the connection. The material properties, required for the creep model, were determined experimentally and predictions of the model were compared to results of longterm connection tests. The study confirmed that timber members jointed with non-metallic connectors have a significantly improved fire performance to timber joints using metallic connections. Models developed and proposed to predict fire performance gave accurate predictions of time to failure. It was concluded that non-metallic connections showed more creep per load per connector, than metallic connections. However, the ratio between initial deflection and creep (relative creep) and the ratio between load level and creep were shown to be similar for metallic and non-metallic connections.

Countries around the world set ambitious targets to substantially reduce their greenhouse gasses emissions, including those which come from electricity sector. This requires a transition to a low carbon electricity generation and supply system, which in part, can be met by increasing distributed generation (DG) connection and implementing demand side response (DSR) programme on distribution network. Therefore, the role of distribution network operators (DNOs) in facilitating the connection of new DG and the implementation of DSR programme is vital. In order to encourage DNOs to be more active in the low carbon transition, the energy regulator needs to set up financial incentives for DNOs. Current DG incentive mechanism, which is applied in the UK, aims to incentivise DNOs based on the amount of DG capacity connected to the network. Consequently, in a generation-dominated area, the incentives might not be sufficient to cover the reinforcement required for connecting DGs, which in turn, the output energy from DGs will be excessively curtailed. Therefore, this research proposes a new approach, called energy-based DG incentive mechanism. This mechanism will incentivise DNOs based on the utilization of available DG energy on the network and its relation with the requirement of network reinforcement. In terms of DSR incentives, different mechanisms have been applied in some countries, including Australia and USA. Some of the mechanisms incentivise DNOs based on the investment cost or forgone revenue related to DSR initiatives, as implemented in demand management incentive and rate of return mechanisms. Other mechanisms aim to incentivise DNOs based on the energy savings or avoided costs of supply associated with DSR participation, as implemented in shared savings and avoided cost mechanisms. Those mechanisms operate independently without any correlation between them. Therefore, this research develops a new approach to assess the relation between DSR investment cost and DSR participation, called energy-based DSR incentive mechanism. This mechanism will incentivise DNOs based on the utilization of available DSR energy on the network and its relation with the required investment. Comparing with current incentive mechanisms, both energy-based DG incentive and energy-based DSR incentive can reflect the effectiveness of DNOs to deal with the required investments in association with DG connection and DSR implementation on their network.

A conexão do implante com o componente protético é associado a remodelação óssea ao seu redor por servir de nichos para a colonização bacteriana. A proposta deste estudo é verificar se a vedação da conexão com dimetacrilato promove uma perda óssea menor. Foram utilizados 20 implantes ósseos Bone Level® Straumann, indicados para reabilitação protética unitária cimentada. Os pilares protéticos foram instalados nos grupos controle e experimental, adicionando-se o dimetacrilato à interface da conexão protética. Foram realizadas radiografias iniciais no dia da instalação do pilar e outra radiografia após 6 meses. As radiografias foram comparadas e medidas quanto a área de remodelação e perda vertical. A mediana da perda óssea em área foi de -1,16 mm2 e -1,05 mm2 e a média da perda em altura foi de -0.13 mm (±0,05) e -0,05 mm (±0,04) no grupo controle e experimental respectivamente. Os resultados não apresentaram diferença estatística significante em p > 0,05. Apesar de já ser comprovada a eficácia da vedação da interface com o dimetacrilato, o procedimento não foi suficiente para influenciar na remodelação óssea ao redor dos implantes. Entretanto, mais estudos devem ser desenvolvidos a fim de verificar se a vedação ajuda na sobrevivência dos implantes e incidência de peri-implantite. / The implant connection with the prosthetic component is associated with bone loss around the implants to serve as niche for bacterial colonization. The purpose of this study is to verify if sealing the connection with dimethacrylate promotes a lower bone loss. Twenty Straumann ® Bone Level implants were used, indicated for unitary cemented prosthetic rehabilitation. The abutments were installed in the control and experimental groups, adding the dimethacrylate to the prosthetic connection interface. Initial radiographs were obtained right after the pillar installation and another radiograph after 6 months. The radiographs were compared and measured as the area of remodeling and vertical loss. The mean bone loss in area was -1.16 mm2 and -1.05 mm2 and the average height loss was -0.13 mm (± 0.05) -0.05 mm (± 0.04) in the control and experimental group respectively. The results showed no statistically significant difference at p > 0.05. Although a study demonstrate the efficacy of the interface with the sealing dimethacrylate, the procedure was not sufficient to influence the bone remodeling around the implants. However, more studies are needed to verify that the seal helps the survival of implants and incidence of peri-implantitis.

The high complexity existent in businesses has required managers to rely on accurate and up to date information. Over the years, many tools have been created to give support to decision makers, such as discrete event simulation and artificial neural networks. Both tools have been applied to improve business performance; however, most of the time they are used separately. This research aims to interpret artificial neural network models that are applied to the data generated by a simulation model and determine which inputs have the most impact on the output of a business. This would allow prioritization of the variables for maximized system performance. A connection weight approach will be used to interpret the artificial neural network models. The research methodology consisted of three main steps: 1) creation of an accurate simulation model, 2) application of artificial neural network models to the output data of the simulation model, and 3) interpretation of the artificial neural network models using the connection weight approach. In order to test this methodology, a study was performed in the raw material receiving process of a manufacturing facility aiming to determine which variables impact the most the total time a truck stays in the system waiting to unload its materials. Through the research it was possible to observe that artificial neural network models can be useful in making good prediction about the system they model. Moreover, through the connection weight approach, artificial neural network models were interpreted and helped determine the variables that have the greatest impact on the modeled system. As future research, it would be interesting to use this methodology with other data mining algorithms and understand which techniques have the greatest capabilities of determining the most meaningful variables of a model. It would also be relevant to use this methodology as a resource to not only prioritize, but optimize a simulation model.

The human population is rapidly urbanizing, creating dramatic changes in local land use and land cover, unprecedented species loss, and a society increasingly disconnected from nature. Nature, specifically biodiversity, has been shown to provide benefits and enhance well-being to humans. Living in an environment with reduced opportunity to interact with or experience biodiversity has increasingly been recognized as both a public health and environmental issue, whereby separation from nature can negatively impact human well-being and how humans value nature, diminishing interest in and understanding of nature and its conservation. Because urban living reduces contact with nature, it is imperative to understand how urban residents perceive and benefit from urban nature to better manage urban biodiversity to both support human well-being and conservation efforts. This study examines how urbanites perceive and benefit from two types of urban nature, trees and birds, by combining surveys of local residents with tree and bird data collected in two Midwestern agricultural cities, Cedar Rapids and Iowa City, Iowa from neighborhoods of varying urban intensity. A residential survey was distributed to these neighborhoods during the summer of 2018 to assess resident perceptions of neighborhood biodiversity and its benefits. In general, residents were not able to assess relative levels of biodiversity compared to other neighborhoods, except in the case of high tree species richness. There was a strong relationship between perceived biodiversity and actual biodiversity, as well as reported knowledge of a given taxon, but only residential perceptions of biodiversity, not actual biodiversity, were strongly related to reported benefits. Respondent perceptions of the influence of trees on their well-being exhibited strong relationships with a person’s connection to trees. Reported influence of birds on well-being was strongly related to a person’s connection to trees, connection to birds, and landscaping practices to support wild species in their yards. Actual bird species richness was significantly negatively related to perceived influence of birds on well-being. Perceived nuisances associated with trees were significantly negatively related to perceived tree species richness, while a person’s connection to trees was strongly positively related to tree nuisances. These results indicate that reported perceptions of the benefits from biodiversity are most heavily influenced by resident perceptions of biodiversity itself and orientation toward nature. This finding also implies that residents benefit from the presence of biodiversity, but that perceived benefits are only related to respondent perceptions of biodiversity, not to actual biodiversity. Further research is necessary to understand why and how this paradox occurs, yet this study provides reason to support efforts to increase knowledge of species as well as provide biodiverse environments that create opportunities for interaction with urban nature. Providing both would strengthen urban resident well-being and support biodiversity and conservation initiatives within cities.

In this report, we study various nonlinear wave equations arising in mathematical physics and investigate the existence of solutions to these equations using variational methods. In particular, we look for particle-like traveling wave solutions known as solitary waves. This study is motivated by the prevalence of solitary waves in applications and the rich mathematical structure of the nonlinear wave equations from which they arise. We focus on a semilinear perturbation of Maxwell's equations and the nonlinear Klein - Gordon equation coupled with Maxwell's equations. Physical ramifications of these equations are also discussed.

The main aim of the project is to launch multiple processes and have those processes communicate with each other using peer to peer communication to eliminate the problems of multiple processes running on a single server, and multiple processes running on inhomogeneous servers as well as the problems of scalability. This entire process is done using MPICH which is a high performance and portable implementation of Message Passing Interface standard. The project involves setting up the passwordless authentication between two local servers with the help of SSH connection. By establishing a peer to peer communication and by using a unique shell script which is written using MPICH and its derivatives, I am going to demonstrate the process of inter-process communication between the servers.

Abstract The aim of this study is to examine and analyze the advantages and limitations of practicum at the HR-program at Uppsala university in the years of 1986-1995 through summarized practicum reports, while focusing on learning in relation to academically based employability. This approach is used to further understand the influence practicum has on employability in relation to the three objectives of higher education. The three objectives are; the usefulness-, competitive- and literate perspective.   The study partly contains an account of the students own experiences and thoughts regarding the practicum as well as a summary and an analysis of the content of said practicum in relation to the education and academically based employability. The research questions of this study seeks to answer the motives and background of the practicum and also the benefits and limitations that comes with it. The data of this study consist of individual summary reports that the students have made in connection to the semester in which the practicum took place. The summaries contain some of the tasks that the students performed but also an account of the students own thoughts and experiences of their practicum.   Method: The data collection method consists of qualitative content analysis and a semi-structured interview.   The results show that the students believe that the practicum has contributed to improve their own employability by providing better capabilities and a deeper understanding of their professional field. The results of the study also show that a big part of the practicum has involved informal learning as well as adaptive- and development learning which has contributed to the development of the students. The conclusion is that the practicum has been important to the students as it has contributed to their personal development and also improved their employability.