Numerical descriptors, beginning with Wiener, and then named topological indices by Hosoya, have gained gradually increasing importance along with other descriptors for use in QSAR and QSPR studies. Being able to estimate the physical or chemical properties of a yet nonexistent substance as close as possible is very important due to huge consumption of time and money upon direct synthesis. In addition, one may face safety problem as in the case of explosives. There have been almost hundred topological indices so far in the chemical graph theory literature. However, there is no topological index which is generalizable to all kinds of molecules. In the present study, a novel topological index (TG Index) has been developed and applied to a wide range of organic molecules including explosives for modeling their physical, structural and molecular orbital properties. The index yielded quite successful correlation data with most of the properties considered in this study.

In this study, dynamic effects on high speed railway bridges under moving traffic are investigated. Within this context, the clear definition of the possible dynamic effects is provided and the related studies that exist in literature are investigated. In the light of those studies, analytical procedures that are defined to find the critical dynamic responses such as deflections, accelerations and resonance conditions are examined and a MatLab programming language is written to obtain the responses for different train loading and velocity values. The reliability of the written program is conformed by comparing the results with the related studies in literature. In addition to the analytical procedures, the approaches in the European standards concerning the dynamic effects of railway traffic are defined. A case study is investigated for a bridge that is in the scope of the Ankara-Sivas High Speed Railway Project. The related bridge is modeled by using finite element program, SAP2000 according to the definitions that are stated in European standards. The related high speed railway bridge is analysed with a real train which is French TGV together with the HSLM trains that are defined in Eurocode and the results obtained are compared with each other. This study also includes the analysis of the bridges performed for 7 different stiffness and 3 different mass values to determine the parameters affecting dynamic behaviour.

Proper bridge design is based on consideration of structural, hydraulic, and geotechnical conformities at an optimum level. The objective of this study is to develop an optimization-based methodology to select appropriate dimensions for components of a river bridge such that the aforementioned design aspects can be satisfied jointly. The structural and geotechnical design parts uses a statisticallybased technique, artificial neural network (ANN) models. Therefore, relevant data of many bridge projects were collected and analyzed from different aspects to put them into a matrix form. ANN architectures are used in the objective function of the optimization problem, which is modeled using Genetic Algorithms with penalty functions as constraint handling method. Bridge scouring reliability comprises one of the constraints, which is performed using Monte-Carlo Simulation technique. All these mechanisms are assembled in a software framework, named as AIROB. Finally, an application built on AIROB is presented to assess the outputs of the software by focusing on the evaluations of hydraulic &ndash / structure interactions.

Integral bridges (IBs) are defined as a class of rigid frame bridges with a single row of piles at the abutments cast monolithically with the superstructure. In the last decade, IBs have become very popular in North America and Europe as they provide many economical and functional advantages. However, standard design methods for IBs have not been established yet. Therefore, most bridge engineers depend on the knowledge acquired from performance of previously constructed IBs and the design codes developed for conventional jointed bridges to design these types of bridges. This include the live load distribution factors used to account for the effect of truck loads on bridge components in the design as well as issues related to the seismic design of such bridges. Accordingly in this study issues related to live load effects as well as seismic effects on IB components are addressed in two separate parts. In the first part of this study, live load distribution formulae for IB components are developed and verified. For this purpose, numerous there dimensional and corresponding two dimensional finite element models (FEMs) of IBs are built and analyzed under live load. The results from the analyses of two and three dimensional FEMs are then used to calculate the live load distribution factors (LLDFs) for the components of IBs (girders, abutments and piles) as a function of some substructure, superstructure and soil properties. Then, live load distribution formulae for the determination of LLDFs are developed to estimate to the live load moments and shears in the girders, abutments and piles of IBs. It is observed that the developed formulae yield a reasonably good estimate of live load effects in IB girders, abutments and piles. In the second part of this study, seismic performance of IBs in comparison to that of conventional bridges is studied. In addition, the effect of several structural and geotechnical parameters on the performance of IBs is assessed. For this purpose, three existing IBs and conventional bridges with similar properties are considered. FEMs of these IBs are built to perform nonlinear time history analyses of these bridges. The analyses results revealed that IBs have a better overall seismic performance compared to that of conventional bridges. Moreover, IBs with thick, stub abutments supported by steel H piles oriented to bend about their strong axis driven in loose to medium dense sand are observed to have better seismic performance. The level of backfill compaction is found to have no influence on the seismic performance of IBs.

The purpose of this research is to study the effect of the thermal treatment on the devices. We dissolved polymer light emitting materials in different solvents to discuss the influence on polymer thin film and device efficiency at different thermal conditions. We confirmed that the best thermal condition was changed as that of solvent changes. In this study, we dissolved polymer blue light material¡ÐBP105 in Toluene and o-xylene. The glass transition temperature (Tg) of BP105 is 120.7¢J, and the boiling point of Toluene and o-xylene were 110 and 145¢J. That is namely the boiling point of Toluene and o-xylene are lower and higher, respectively, than the Tg of BP105. This makes us to compares the thermal treatment conditions on different influence from different boiling point of solvents. The interrelations between the thermal treatment temperature, the boiling point of solvents and the glass transition temperature of polymer is an interesting topic to study, because it does affect the surface morphology of polymer thin films and the characteristic of devices. The device structure is as follows: ITO/ PEDOT:PSS/ BP105/ LiF/ Ca/ Al. Known from the experimental results that the spectra and the morphologies of polymer thin films will change in the different thermal treatment condition, and the choice of different solvent will also affect the best thermal treatment condition for device processing. We observed the surface roughness of polymer thin film is one of the important factors to affect the device efficiency in this study. We found that if the boiling point of used solvent was higher than the thermal treatment temperature, which was higher than the Tg of polymer, the surface roughness of polymer thin film is more smooth resulting in higher current injecting and higher stability of the device. The best thermal treatment temperature is 130¢J by using o-xylene as solvent. The surface roughness of polymer thin film is 0.393 nm, and the maximum brightness of the device is 8593 cd/m2 at 12.5 V as a configuration of ITO(1500Å)/PEDOT:PSS(800Å)/BP105(650Å)/LiF(10Å)/ Ca(100Å)/ Al(2000Å). The luminous and the power efficiencies are 3.98 cd/A, and 1.43 lm/W, respectively, at the current density 100 mA/cm2.

No description available.

The TG-43 dosimetry parameters of the AdvantageTM 125I model IAI-125A brachytherapy seed were studied. An investigation using modern MCNP radiation transport code with updated cross-section libraries was performed. Twelve different simulation conditions were studied for a single seed by varying the coating thickness, mass density, photon energy spectrum and cross-section library. The dose rate was found to be 6.3% lower at 1 cm in comparison to published results. New TG-43 dosimetry parameters are proposed. The dose distribution for a brachytherapy eye plaque, model EP917, was investigated, including the effects of collimation from high-Z slots. Dose distributions for 26 slot designs were determined using Monte Carlo methods and compared between the published literature, a clinical treatment planning system, and physical measurements. The dosimetric effect of the composition and mass density of the gold backing was shown to be less than 3%. Slot depth, width, and length changed the central axis (CAX) dose distributions by < 1% per 0.1 mm in design variation. Seed shifts in the slot towards the eye and shifts of the 125I-laden silver rod within the seed had the greatest impact on the CAX dose distribution, changing it by 14%, 9%, 4.3%, and 2.7% at 1, 2, 5, and 10 mm, respectively, from the inner scleral surface. The measured, full plaque slot geometry delivered 2.4% ± 1.1% higher dose along the plaque’s CAX than the geometry provided by the manufacturer and 2.2%±2.3% higher than Plaque SimulatorTM (PS) treatment planning software (version 5.7.6). The D10 for the simulated tumor, inner sclera, and outer sclera for the measured slot plaque to manufacturer provided slot design was 9%, 10%, and 19% higher, respectively. In comparison to the measured plaque design, a theoretical plaque having narrow and deep slots delivered 30%, 37%, and 62% lower D10 doses to the tumor, inner sclera, and outer sclera, respectively. CAX doses at –1, 0, 1, and 2 mm were also lower by a factor of 2.6, 1.72, 1.50, and 1.39, respectively. The study identified substantial sensitivity of the EP917 plaque dose distributions to slot design.

In highway bridge construction, composite curved girder bridges are becoming more popular recently. Reduced construction time, long span coverage, economics and aesthetics make them more popular than the other structural systems. Although there exist some methods for the analysis of such systems, each have shortcomings. The use of Finite Element Method (FEM) among these methods is limited except in the academic environments. The use of commercial FEM software packages in the analysis of such systems is cumbersome as it takes too much time to form a model. Considering such problems a computational software was developed called UTRAP in 2002 which analyzes bridges for construction loads by taking into account the early age deck concrete. As the topic of this thesis work, this program was restructured and new features were added. In the following thesis work, the program structure, modeling considerations and recommendations are discussed together with the parametric studies.

ABSTRACT SCOUR AND SCOUR PROTECTION AT BRIDGE ABUTMENTS Kayat&uuml / rk, Serife Yurdag&uuml / l Ph. D., Department of Civil Engineering Supervisor: Prof. Dr. Mustafa G&ouml / g&uuml / S Co-Supervisor: Dr. Mehmet Ali K&ouml / kpinar January 2005, 213 pages Bridge failures are mainly caused by scouring the bed material around bridge foundations during flood. In this study, scour phenomenon around bridge abutments is experimentally studied. Effect of abutment size, location and size of the collars placed around the abutments, time evaluation of scour hole around the abutment, scour characteristics of abutment and pier interaction were experimentally investigated. Scour measurements were conducted in a rectangular channel of 30 m long and 1.5 m wide filled with erodable uniform sediment. In the first part of the study, in order to investigate the size effect of the abutment on the maximum scour depth, abutments of nine different sizes were tested for three different water depths. It was found that the length of the abutment is more important parameter than the width of it. Secondly, efficiency of various sizes of collars, which are used to reduce the local scour depth, located at different elevations around the abutments was determined. It was noticed that when the collar width was increased and placed at or below the bed level, the reduction in scour depth increases considerably. Some tests for partial-collar arrangements around the abutments were conducted and it was shown that instead of full-collar one can use partial-collar arrangements around the abutments to achieve the same efficiency as the full-collar. Time development of scour holes around the abutments with and without collar cases were recorded. It was observed considerable reductions in scour depths around the abutments can be obtained with collars compared to the cases in which there are no collars over the same time period. Finally, a series of experiments were carried out to investigate the interaction between bridge abutments and piers related to the local scour around them. Based on the experiments conducted with two different abutment lengths and pier diameters varying the lateral distances between them it was observed that scour depth reduction capacities of collars vary significantly while comparing a single abutment or pier.

Submitted by Suethene Souza (suethene.souza@ufpe.br) on 2015-03-09T17:30:33Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Marco Antonio Granha.pdf: 1263356 bytes, checksum: 9dc72d1fa8943f95af039a3ad5c365bd (MD5) / Made available in DSpace on 2015-03-09T17:30:33Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Marco Antonio Granha.pdf: 1263356 bytes, checksum: 9dc72d1fa8943f95af039a3ad5c365bd (MD5) Previous issue date: 2014-04-30 / O presente estudo teve como objetivo explicar como as empresas de serviços contábeis se adaptaram a NBC TG 1000 – Contabilidade para Pequenas e Médias Empresas para a preparação, elaboração e divulgação das demonstrações contábeis de seus clientes. Para alcançar esse objetivo, a pesquisa utilizou uma abordagem de métodos misto sequencial, sendo inicialmente aplicado um questionário de pesquisa para as 148 empresas de serviços contábeis associadas ao SESCAP-PE obtendo 35 respostas representando a etapa quantitativa do estudo. Em seguida, entrevistas semiestruturadas baseadas em um roteiro elaborado a partir dos resultados da etapa inicial, foram realizadas com 8 sócios de 7 empresas de serviços contábeis de reconhecida experiência e competência técnica, representando a etapa qualitativa do estudo. Os resultados da etapa inicial da pesquisa evidenciaram que a maioria das empresas pesquisadas não adotam plenamente ou não conhecem a norma. Na segunda etapa da pesquisa, onde se buscou o aprofundamento das questões apontadas na etapa inicial, os resultados revelaram que a adoção da NBC TG 1000 pelas empresas de serviços contábeis ocorreu de forma parcial, sendo utilizadas apenas as seções relativas a elaboração das demonstrações contábeis. Os principais fatores que dificultaram a adoção plena da norma evidenciados pela pesquisa foram: a complexidade do texto do pronunciamento e o prazo considerado muito curto entre a divulgação e sua obrigatoriedade de adoção, a necessidade de cumprimento das exigências fiscais, o conhecimento ainda em fase de consolidação dos profissionais da contabilidade, a falta de interesse e conhecimento dos clientes em relação a importância das demonstrações contábeis e a resistência para entrega das informações e documentações em tempo hábil para o registro tempestivo das transações. Embora os respondentes tenham adotado de forma parcial a norma, todos consideram positivo o processo de convergência ao padrão internacional de contabilidade.