The cross sections for neutral current (NC) deep inelastic scattering (DIS) in e+p collisions with a longitudinally polarised positron beam are measured at high momentum transfer squared (Q2 > 185 GeV2) at the ZEUS detector at HERA. The HERA accelerator provides e+-p collisions at a centre-of-mass energy of 318 GeV, which allows the weak contribution to the NC process to be studied at high Q2. The measurements are based on a data sample with an integrated luminosity of 135.5 pb-1 collected with the ZEUS detector in 2006 and 2007. The single differential NC cross sections dsigma/dQ2, dsigma/dx and dsigma/dy and the reduced cross section are measured. The structure function xF3 is determined by combining the e+p NC reduced cross sections with the previously measured e-p measurements. The interference structure function xF 3^gamma,Z is extracted at Q2 = 1500 GeV2. The cross-section asymmetry between the positive and negative polarisation of the positron beam is measured and the parity violation effects of the electroweak interaction are observed. The predictions of the Standard Model of particle physics agree well with the measurements.

The relations between monetary policies, asset prices, and economic growth are important and fundamental questions in macroeconomics. To address these issues, several empirical works have been conducted to investigate these relations. However, few of them have documented whether these relations differ across regimes. In this context, the general motivation of this thesis is to use dependent regime models to examine these relations for the Canadian case. Chapter one empirically analyzes the interest rate behaviour of the Canadian monetary authorities by taking into account the asymmetry in the loss function. We employ a switching regime framework using two estimation strategies: First, we follow Caner and Hansen (2004) Threshold approach. Under this procedure we estimate the threshold values, using the Taylor empirical rules. Second, we estimate the asymmetric policy reaction function following Favero and Rovelli’s (2003) approach. The results reveal that the monetary authorities showed asymmetric preferences and that its reaction function can be better modeled with a nonlinear model. The main contribution of this chapter is to successfully interpret the parameters associated with the Bank of Canada preferences, something that Rodriguez (2008) could not do. Chapter two tries to estimate the interest rate behaviour of the Canadian monetary authorities by expanding the arguments of the loss function for fluctuations in asset prices. Using the same methodology as in the first chapter, our findings suggest that the augmented nonlinear reaction function is a good fit for the data and gives new relevant insights into the influence of asset prices on Canadian monetary policy. These findings about the role of asset prices in the reaction function of the Bank of Canada provide relevant insights regarding the opportunities and limitations of incorporating financial indicators in monetary policy decision making. They also provide financial market participants, such as analysts, bankers and traders, with a better understanding of the impact of stock market index prices on Bank of Canada policy. Stock market stabilization plays a larger role in the interest rate decisions of the Bank of Canada than it is willing to admit. Chapter three provides new evidence on the relation between inflation, relative price variability and economic growth to a panel of Canadian provinces over the period 1981-2008. We use the Bick and Nautz (2008) modified version of Hansen’s (1999) Panel Threshold Model. The evidence strongly supports the view that the relationship between inflation and economic growth is nonlinear. Further investigation suggests that relative price variability is one of the important channels through which inflation affects economic performance in Canadian provinces. When taking into account the cross-section dependence, we find that the critical threshold value slightly changes. It is desirable to keep the inflation rate in a moderate inflation regime because it may be helpful for the achievement of sustainable economic growth. The results seem to indicate that inflation that is too high or too low may have detrimental effects on economic growth.

For the education of X-ray imaging, having a detailed knowledge on the interaction of radiation with matter is very important. Also the generation and detection concepts of the X-ray have to be grasped well. Sometimes it is not easy to visualize the interactions and assess the scheme in quantum physics level for the medical doctors and the engineers who have not studied on the modern physics in an appropriate level. This thesis aims to visualize these interactions, X-ray generation and detection, and computerized tomographic imaging. With these simulations, the user can 1) observe and analyze which type of interaction occurs under which condition, 2) understand the interaction cross sections and interaction results, 3) visualise X-ray generation and detection features, 4) clarify the method of image reconstruction, and the features affecting the image quality in computerized tomography system. This is accomplished by changing the controllable variables of the radiation and the systems with the provided interfaces. In this thesis, JAVA/FLASH based simulation interfaces are designed to easily assess the subject. The benefits of these software are their ability to execute the programs prepared on the World Wide Web media. The interfaces are accessible from anywhere, at any time.

SectionBuilder is an innovative finite element based tool, developed for analysis and design of composite beam cross-sections. The tool can handle the cross-sections with parametric shapes and arbitrary configurations. It can also handle arbitrary lay-ups for predefined beam cross-section geometries in a consistent manner. The material properties for each layer of the cross-section can be defined on the basis of the design requirements. This tool is capable of dealing with multi-cell composite cross-sections with arbitrary lay-ups. It has also the benefit of handling the variation of thickness of skin and D-spars for beams such as rotor blades. A typical cross-section is considered as a collection of interconnected walls. Walls with arbitrary lay-ups based on predefined geometries and material properties are generated first. The complex composite beam cross-sections are developed by connecting the walls using various types of connectors. These connectors are compatible with the walls, i.e., the thickness of the layers of the walls must match with those of the connectors at the place of connection. Cross-sections are often reinforced by core material for constructing realistic rotor blade cross-sections. The tool has the ability to integrate core materials into the cross-sections. A mapped mesh is considered for meshing parametric shapes, walls and various connectors, whereas a free mesh is considered for meshing the core materials. A new algorithm based on the Delaunay refinement algorithm is developed for creating the best possible free mesh for core materials. After meshing the cross-section, the tool determines the sectional properties using finite element analysis. This tool computes sectional properties including stiffness matrix, compliance matrix, mass matrix, and principal axes. A visualization environment is integrated with the tool for visualizing the stress and strain distributions over the cross-section.

Ion mobility spectrometry (IMS) separates ions on the basis of ion-neutral collision cross-sections (CCS, [omega]), which are determined by the geometry or conformation of the ions. The size-based IM separation can be extended to distinguish conformers that have different shapes in cases where shape differences influence the accessible surface area of the molecule. In recent years, IM has rapidly evolved as a structural characterization technique, which has applied on various structural biology problems. In this work, IMS is combined with molecular dynamics simulation (MDS), specially the integrated tempering sampling molecular dynamics simulation (ITS-MDS) to explore the gas-phase conformation space of two molecular systems (i) protonated tryptophan zipper 1 (trpzip1) ions and its six derivatives (ii) alkali metal ion (Na, K and Cs) adducts of gramicidin A (GA). The structural distributions obtained from ITS-MDS are compared well with results obtained from matrix-assisted laser desorption ionization-ion mobility-mass spectrometry (MALDI-IM-MS) for trpzip 1 series and electrospray ionization-ion mobility-mass spectrometry (ESI-IM-MS) for alkali metal ion adducts of GA. Furthermore, the solvent dependence on conformational preferences of the GA dimer is investigated using a combination of mass spectrometry techniques, viz. ESI-IM-MS and hydrogen/deuterium exchange (HDX)-MS, and MDS. The IM experiments reveal three distinct gramicidin A species, detected as the sodium ion adduct ions, [2GA + 2Na]²⁺, and the equilibrium abundances of the dimer ions varies with solvent polarity. The solution phase conformations are assigned as the parallel and anti-parallel [beta]-helix dimer, and the anti-parallel dimer is the preferred conformation in non-polar organic solvent. The calculated CCS profiles by ITS-MDS agree very well with the experimentally measured CCS profiles, which underscore the utility of the method for determining candidate structures as well as the relative abundances of the candidate structures. The benefit of combining ion mobility measurements with solution-phase H/D exchange is allowing identifications and detail analysis of the solution-phase subgroup conformations, which cannot be uncovered by one method alone.

This thesis consists of an overview and five essays. The purpose of the thesis is to show how economics can contribute to a better understanding of medical practice variations – why they exist, their consequences, and the extent to which they can – and should – be influenced. The first essay, Econometric analysis of variation in cesarean section rates – a cross-sectional study of 59 obstetrical departments in Sweden, is an attempt to identify the causes of variation in cesarean section rates, and to discuss their economic consequences. The econometric model applied explains 27 percent of the variation. We conclude that the unexplained variation in cesarean section rates indicates inefficiency, mainly due to over-utilisation. Estimates of the economic consequences indicate an additional cost for "unnecessary" cesarean sections of 13-16 million SEK per year. The welfare loss to society due to undesired variation is tentatively estimated to be about twice as high. In the second essay, Estimating the effect of cesarean section rate on health outcome – evidence from Swedish hospital data, we test the null hypothesis of a zero effect of cesarean section rate on health outcome, against the alternative of a positive effect. We could not reject the null hypothesis of a zero effect, i.e., we did not find any significant positive relationship between cesarean section rate and health outcome, in terms of perinatal mortality or rate of asphyxia. In the third essay, Benchmarking in obstetric care – a comparative study based on data envelopment analysis (DEA), we apply the DEA method to compare technical efficiency (productivity) of inpatient obstetric care in Swedish hospitals in 1994 and 1995. The results indicate an average potential for enhanced productivity of at least 6-7 percent each year. Most hospitals show decreasing productivity 1994-1995, partly due to inability to adjust production capacity and costs to a decreasing demand. The last two essays apply a new method – Quality Satisfaction Performance (QSP) – for incorporating patient perspectives into the management of health care, i.e., as a basis for quality improvement. Change-oriented patient questionnaires – testing a new method at three departments of ophthalmology, is a pilot study. The results show consistently high patient satisfaction indices. Satisfaction varies somewhat among the different patient segments and departments. We conclude that decisions on improvements must be preceded by thorough assessment of costs as well as effects associated with the various changes. The last essay, Patient satisfaction and priority setting – an economic approach, aims at analysing if and how priorities according to the QSP approach are influenced when an economic perspective is explicitly included. This is accomplished by a cost-effectiveness analysis of certain proposed changes/improvements, and a cost-benefit analysis based upon the patients` willingness-to-pay for these changes. Our results show that the ranking between various improvements is strongly influenced when an economic dimension is included. We conclude that even a methodologically appropriate measurement of patient satisfaction may lead to cost-ineffective priority setting, unless economic consequences are explicitly considered. / Diss. (sammanfattning) Stockholm : Handelshögsk., 2001

The current design procedure for steel frame structures is a two-step process including an elastic analysis to determine design actions and a separate member capacity check. This design procedure is unable to trace the full range of load-deflection response and hence the failure modes of the frame structures can not be accurately predicted. In recent years, the development of advanced analysis methods has aimed at solving this problem by combining the analysis and design tasks into one step. Application of the new advanced analysis methods permits a comprehensive assessment of the actual failure modes and ultimate strengths of structural steel systems in practical design situations. One of the advanced analysis methods, the refined plastic hinge method, has shown great potential to become a practical design tool. However, at present, it is only suitable for a special class of steel frame structures that is not subject to lateral torsional buckling effects. The refined plastic hinge analysis can directly account for three types of frame failures, gradual formation of plastic hinges, column buckling and local buckling. However, this precludes most of the steel frame structures whose behaviour is governed by lateral torsional buckling. Therefore, the aim of this research is to develop a practical advanced analysis method suitable for general steel frame structures including the effects of lateral-torsional buckling. Lateral torsional buckling is a complex three dimensional instability phenomenon. Unlike the in-plane buckling of beam-columns, a closed form analytical solution is not available for lateral torsional buckling. The member capacity equations used in design specifications are derived mainly from testing of simply supported beams. Further, there has been very limited research into the behaviour and design of steel frame structures subject to lateral torsional buckling failures. Therefore in order to incorporate lateral torsional buckling effects into an advanced analysis method, a detailed study must be carried out including inelastic beam buckling failures. This thesis contains a detailed description of research on extending the scope of advanced analysis by developing methods that include the effects of lateral torsional buckling in a nonlinear analysis formulation. It has two components. Firstly, distributed plasticity models were developed using the state-of-the-art finite element analysis programs for a range of simply supported beams and rigid frame structures to investigate and fully understand their lateral torsional buckling behavioural characteristics. Nonlinear analyses were conducted to study the load-deflection response of these structures under lateral torsional buckling influences. It was found that the behaviour of simply supported beams and members in rigid frame structures is significantly different. In real frame structures, the connection details are a decisive factor in terms of ultimate frame capacities. Accounting for the connection rigidities in a simplified advanced analysis method is very difficult, but is most critical. Generally, the finite element analysis results of simply supported beams agree very well with the predictions of the current Australian steel structures design code AS4100, but the capacities of rigid frame structures can be significantly higher compared with Australian code predictions. The second part of the thesis concerns the development of a two dimensional refined plastic hinge analysis which is capable of considering lateral torsional buckling effects. The formulation of the new method is based on the observations from the distributed plasticity analyses of both simply supported beams and rigid frame structures. The lateral torsional buckling effects are taken into account implicitly using a flexural stiffness reduction factor in the stiffness matrix formulation based on the member capacities specified by AS4100. Due to the lack of suitable alternatives, concepts of moment modification and effective length factors are still used for determining the member capacities. The effects of connection rigidities and restraints from adjacent members are handled by using appropriate effective length factors in the analysis. Compared with the benchmark solutions for simply supported beams, the new refined plastic hinge analysis is very accurate. For rigid frame structures, the new method is generally more conservative than the finite element models. The accuracy of the new method relies on the user's judgement of beam segment restraints. Overall, the design capacities in the new method are superior to those in the current design procedure, especially for frame structures with less slender members. The new refined plastic hinge analysis is now able to capture four types of failure modes, plastic hinge formation, column buckling, local buckling and lateral torsional buckling. With the inclusion of lateral torsional buckling mode as proposed in this thesis, advanced analysis is one step closer to being used for general design practice.

Until recently, the hot-rolled steel members have been recognized as the most popular and widely used steel group, but in recent times, the use of cold-formed high strength steel members has rapidly increased. However, the structural behavior of light gauge high strength cold-formed steel members characterized by various buckling modes is not yet fully understood. The current cold-formed steel sections such as C- and Z-sections are commonly used because of their simple forming procedures and easy connections, but they suffer from certain buckling modes. It is therefore important that these buckling modes are either delayed or eliminated to increase the ultimate capacity of these members. This research is therefore aimed at developing a new cold-formed steel beam with two torsionally rigid rectangular hollow flanges and a slender web formed using intermittent screw fastening to enhance the flexural capacity while maintaining a minimum fabrication cost. This thesis describes a detailed investigation into the structural behavior of this new Rectangular Hollow Flange Beam (RHFB), subjected to flexural action The first phase of this research included experimental investigations using thirty full scale lateral buckling tests and twenty two section moment capacity tests using specially designed test rigs to simulate the required loading and support conditions. A detailed description of the experimental methods, RHFB failure modes including local, lateral distortional and lateral torsional buckling modes, and moment capacity results is presented. A comparison of experimental results with the predictions from the current design rules and other design methods is also given. The second phase of this research involved a methodical and comprehensive investigation aimed at widening the scope of finite element analysis to investigate the buckling and ultimate failure behaviours of RHFBs subjected to flexural actions. Accurate finite element models simulating the physical conditions of both lateral buckling and section moment capacity tests were developed. Comparison of experimental and finite element analysis results showed that the buckling and ultimate failure behaviour of RHFBs can be simulated well using appropriate finite element models. Finite element models simulating ideal simply supported boundary conditions and a uniform moment loading were also developed in order to use in a detailed parametric study. The parametric study results were used to review the current design rules and to develop new design formulae for RHFBs subjected to local, lateral distortional and lateral torsional buckling effects. Finite element analysis results indicate that the discontinuity due to screw fastening has a noticeable influence only for members in the intermediate slenderness region. Investigations into different combinations of thicknesses in the flange and web indicate that increasing the flange thickness is more effective than web thickness in enhancing the flexural capacity of RHFBs. The current steel design standards, AS 4100 (1998) and AS/NZS 4600 (1996) are found sufficient to predict the section moment capacity of RHFBs. However, the results indicate that the AS/NZS 4600 is more accurate for slender sections whereas AS 4100 is more accurate for compact sections. The finite element analysis results further indicate that the current design rules given in AS/NZS 4600 is adequate in predicting the member moment capacity of RHFBs subject to lateral torsional buckling effects. However, they were inadequate in predicting the capacities of RHFBs subject to lateral distortional buckling effects. This thesis has therefore developed a new design formula to predict the lateral distortional buckling strength of RHFBs. Overall, this thesis has demonstrated that the innovative RHFB sections can perform well as economically and structurally efficient flexural members. Structural engineers and designers should make use of the new design rules and the validated existing design rules to design the most optimum RHFB sections depending on the type of applications. Intermittent screw fastening method has also been shown to be structurally adequate that also minimises the fabrication cost. Product manufacturers and builders should be able to make use of this in their applications.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Em virtude do elevado grau de desenvolvimento da tecnologia em sua produção, a utilização de perfis tubulares é grandemente difundida em países como, por exemplo, Canadá, Inglaterra, Alemanha e Holanda. A utilização de tais perfis no Brasil era bastante restrita, limitando-se a coberturas espaciais. Atualmente, a situação do mercado brasileiro começa a se alterar em decorrência do significativo aumento da oferta de perfis tubulares estruturais. Este trabalho apresenta uma análise de ligações tipo KK com perfis tubulares circulares (CHS), com o intuito de estabelecer um quadro comparativo entre as formulações analíticas de dimensionamento proposta pelo Eurocode 3 Parte 1.8, 2 edição do guia de projeto de ligações tubulares do CIDECT, ABNT NBR 16239:2013, pelas equações propostas por Paul e Kurobane e critérios de deformação limite. A calibração de um modelo foi feita com dados numéricos e experimentais. Para cada um dos tipos de ligações analisadas, desenvolveu-se um modelo em elementos finitos no programa Ansys. As não-linearidades física e geométrica foram incorporadas aos modelos, a fim de se mobilizar totalmente a capacidade resistente da ligação. A não-linearidade do material foi considerada com o uso do critério de plastificação de Von Mises através de uma lei constitutiva tensão versus deformação bilinear. A não-linearidade geométrica foi introduzida no modelo através da Formulação de Lagrange Atualizado considerando-se a previsão de grandes deformações de forma a permitir a redistribuição de carregamento na ligação após o escoamento inicial. Foi proposto um modelo de uma treliça espacial composta por perfis tubulares de seção circular para comparar os resultados de análises de uma ligação isolada e a resposta desta mesma ligação como parte de uma treliça em escala real. / Due to the high degree of development of the technology in its production, the use of tubular profiles is greatly widespread in countries such as Canada, England, Germany and Holland. The use of such profiles in Brazil was very restricted, being limited to spatial roofs. Currently, the situation in the Brazilian market begins to change as a result of the significant valeability increase of structural hollow sections. This work presents an analysis of KK connections with circular hollow sections. A comparison between the analytical design formulations proposed by Eurocode 3 Part 1.8, 2nd edition of the design guide of tubular joints of the CIDECT, Brazilian standard ABNT NBR 16239:2013, Paul and Kurobane equations and limit deformation criteria was performed. For each of the joints types analyzed, a finite element model was developed in ANSYS program. The developed model was calibrated against numerical and experimental results. The physical and geometrical non-linearities have been incorporated in the model to mobilize the joint full load capacity. The material nonlinearity was considered by Von Mises criteria through stress versus strain bilinear constitutive law. The geometric non-linearity was introduced in the model by the use of Lagrange Updated Formulation in order to consider the expected large deformation and to allow redistribution of load in the joint after the initial yielding. This work also proposes the modeling of a planar truss made of circular hollow section structures to establish a comparison between a single joint and the response of joint as a part of a full scale truss structure. The modeling of a spatial truss made of circular hollow section structures to establish a comparison between a single joint and the response of joint as a part of a full scale truss structure was proposed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os perfis tubulares sem costura são largamente utilizados em diversos países, porém, no Brasil, o uso desses perfis na construção civil era bastante limitado, restringindo-se praticamente a coberturas espaciais. Considerando uma nova realidade para o uso de perfis tubulares, este trabalho apresenta uma análise de ligações tipo T com perfis tubulares quadrados (SHS) para o banzo e para o montante efetuada com base na norma europeia, Eurocode 3, no CIDECT, na NBR 16239:2013 e ISO 14346 através de um modelo em elementos finitos desenvolvido no programa Ansys. Verificou-se a influência do momento atuante no montante no comportamento global das ligações. As não-linearidades físicas e geométricas foram incorporadas aos modelos, a fim de se mobilizar totalmente a capacidade resistente desta ligação. A não-linearidade do material foi considerada através do critério de plastificação de von Mises através da lei constitutiva tensão versus deformação trilinear de forma a exibir um comportamento elasto-plástico com encruamento. A nãolinearidade geométrica foi introduzida no modelo através da Formulação de Lagrange Atualizado. Os resultados numéricos são avaliados para a ligação em estudo quanto aos modos de falha e a distribuição de tensões. A análise dos momentos resistentes obtidos em comparação com os resultados do modelo numérico, apresentou valores excessivamente a favor da segurança no cálculo utilizando as equações de dimensionamento. Um estudo para fatores de correção das equações de dimensionamento é proposto. / Seamless tubular sections are widely used in many countries, but in Brazil, the use of these profiles in construction is quite limited, being almost restricted to spatial trusses. Considering a new reality for the use of tubular profiles, this Dissertation presents an analysis of "T" joints with square hollow sections (SHS) for the chord and the brace based on the European standard, Eurocode 3, CIDECT Design Guide, NBR 16239:2013 and ISO 14346 through out a finite element model developed in ANSYS program. The main objective of the present investigation is to evaluate the influence of the bending moment over the joint global behavior. The physical and geometrical nonlinearities were incorporated into the models, in order to fully mobilize the joint global response. The nonlinearity of the material was considered by adopting the von Mises yield criteria with a material constitutive law with a multilinear stress versus strain curve associated to a elastic-plastic behavior with hardening. The geometric nonlinearity has been introduced into the model through Updated Lagrangian formulation. The numerical results were evaluated for studied joints in terms of the failure modes and stress distributions. The numerical results are evaluated for binding study on the modes of failure and the stress distribution. The analysis of the resistant moments obtained in comparison with the results of numerical model presented values for safety excessively calculated using equations sizing. A study for the correction equations scaling factors is proposed.