No description available.

The purposes of this study are to investigate the possible effects of variables like testing depth, length to diameter ratio of the probe, presence of disturbed annulus around the borehole etc. on the derived parameters from the pressuremeter test, and to develop possible alternative methods for the determination of undrained shear strength of cohesive soils, and cohesion and internal friction angle of intermediate geomaterials. For this purpose numerical simulations of pressuremeter test were performed. In the study, it is also aimed to investigate the effect of rock quality designation (RQD) or some other rock mass parameters such as geological strength index (GSI) and rock mass rating (RMR) and intact rock strength on the deformation modulus determined from the pressuremeter test. To accomplish this task, Dikmen greywackes, weathered andesites and mudrocks exposed around Ankara - Sincan region were selected for field and laboratory studies. Empirical relationships using GSI, RMR, RQD were developed for the estimation of deformation modulus of greywackes and mudrocks cropping out around Ankara. Numerical simulations revealed the presence of disturbed annulus around the borehole causes underestimation of deformation modulus and overestimation of undrained shear strength. Test depth has no effect on the deformation modulus and undrained shear strength / the effect of length to diameter ratio of the probe on the deformation modulus is minor where as it causes overestimations of undrained shear strength. Pore pressure dissipation in low permeability soils around the pressuremeter was studied using numerical simulations. These analyses suggest that for permeabilities lower that 10-10 m/sec there is no pore pressure dissipation around the pressuremeter probe. It was determined that the inverse analysis yielded successful results for the determination of shear strength parameters of intermediate geomaterials.

The objective of this dissertation is to derive a set of compact physical models addressing power integrity issues in high performance gigascale integration (GSI) systems and three-dimensional (3-D) systems. The aggressive scaling of CMOS integrated circuits makes the design of power distribution networks a serious challenge. This is because the supply current and clock frequency are increasing, which increases the power supply noise. The scaling of the supply voltage slowed down in recent years, but the logic on the integrated circuit (IC) still becomes more sensitive to any supply voltage change because of the decreasing clock cycle and therefore noise margin. Excessive power supply noise can lead to severe degradation of chip performance and even logic failure. Therefore, power supply noise modeling and power integrity validation are of great significance in GSI systems and 3-D systems. Compact physical models enable quick recognition of the power supply noise without doing dedicated simulations. In this dissertation, accurate and compact physical models for the power supply noise are derived for power hungry blocks, hot spots, 3-D chip stacks, and chip/package co-design. The impacts of noise on transmission line performance are also investigated using compact physical modeling schemes. The models can help designers gain sufficient physical insights into the complicated power delivery system and tradeoff various important chip and package design parameters during the early stages of design. The models are compared with commercial tools and display high accuracy.

The 2006 International Technology Roadmap for Semiconductors projects that for 2020, interconnects will be as narrow as 14 nm and will operate at frequencies as high as 50GHz. For a wire that operates at ultra-high frequencies, such that skin depth and the mean free path of the electrons are in the same order, skin effect and surface scattering should be considered simultaneously. This is known as the anomalous skin effect (ASE). The objective of this work is to identify the challenges and opportunities for using GSI interconnects in the nanometer and GHz regime. The increase in the resistivity of a thin wire caused by the ASE is studied. The delay of a digital transmission line resulting from this effect is modeled. Compact models are presented for the bit-rate limit of transmission lines using a general form of resistance that for the first time simultaneously considers dc resistance, skin effect, and surface scattering. A conventional low-loss approximation that is only valid for fast rising signals is also relaxed. The impact of size effects on the design of multi-level interconnect networks is studied. For high-performance chips at the 18 nm technology node, it is shown that despite a more than four times increase in the resistivity of copper for minimum-size interconnects, the increase in the number of metal levels is negligible (less than 7%), and interconnects that will be affected most are so short that their impact on chip performance is inconsequential. It is shown that for low-cost applications where very few wiring pitches are normally used, the number of metal levels needed to compensate for the impact of size effects on the average rc delay of a copper interconnect is drastically high. An optimization methodology has been presented for power distribution interconnects at the local level. For a given IR drop budget, compact models are presented for the optimal widths of power and ground lines in the first two metal levels for which the total metal area used for power distribution is minimized.

The safety performance of nuclear power reactors is a very important factor in evaluating nuclear energy sustainability. Improving the safety performance of nuclear reactors can enhance nuclear energy sustainability as it will improve the environmental indicator used to evaluate the overall sustainability of nuclear energy. Great interest is given now to advanced nuclear reactors especially those using passive safety components. Investigation of the improvement in nuclear safety using advanced reactors was done by comparing the safety performance of a conventional reactor which uses active safety systems, such as Pressurized Water Reactor (PWR), with an advanced reactor which uses passive safety systems, such as AP1000, during a design basis accident, such as Loss of Coolant Accident (LOCA), using the PCTran as a simulation code. To assess the safety performance of PWR and AP1000, the “Global Safety Index” GSI model was developed by introducing three indicators: probability of accident occurrence, performance of safety system in case of an accident occurrence, and the consequences of the accident. Only the second indicator was considered in this work. A more detailed model for studying the performance of passive safety systems in AP1000 was developed. That was done using SCDAPSIM/RELAP5 code as it is capable of modelling design basis accidents (DBAs) in advanced nuclear reactors.

No description available.

This diploma thesis deals with the proposal of an alternative solution to the intersection of Mohelnice North crossroads. It compares the current junction design, which is considered inappropriate, with two new proposals for circular intersections. The aim of the thesis is to propose the resultant junction cheaper, smaller and simpler for users.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-15T16:52:35Z No. of bitstreams: 1 JACQUELINE LIEDJA ARAUJO SILVA CARVALHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1821177 bytes, checksum: 5edf83fb0f87d1e2e3a52d083f218e97 (MD5) / Made available in DSpace on 2018-05-15T16:52:35Z (GMT). No. of bitstreams: 1 JACQUELINE LIEDJA ARAUJO SILVA CARVALHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1821177 bytes, checksum: 5edf83fb0f87d1e2e3a52d083f218e97 (MD5) Previous issue date: 2013-09-26 / O Brasil tem um dos maiores rebanhos bovino leiteiros do mundo. No entanto, apesar de estar entre os grandes produtores mundiais de leite, a pecuária leiteira nacional é bastante heterogênea. Parte de algumas regiões como o Nordeste brasileiro, ainda encontra-se em desenvolvimento para alcançar os padrões de qualidade e quantidade e chegar ao mercado competitivo, como por exemplo, o município de Pombal, que estar localizado no Sertão da Paraíba, área do presente estudo, que é reconhecida em âmbito estadual, por seu potencial leiteiro. Neste contexto, esta pesquisa tem o objetivo de fazer uma análise da sustentabilidade da bovinocultura leiteira de Pombal, nos seus aspectos institucional (tecnológica), social, econômica e ambiental. Para a execução desse estudo, foram necessárias visitas in loco e aplicação de questionários semi-estruturados, a 50 produtores de leite, pertencentes a trinta e duas áreas rurais desse município. A partir das respostas, foram calculados em indicadores, utilizando o método do PNUD/ONU (1998), cujos resultados variaram de 0 (zero) a 100 (cem) e foram divididos em quatro graus de sustentabilidades: crítico, ruim, bom e excelente. Em seguida, aplicado na fórmula matemática denominada de IGS (Índice Global de Sustentabilidade) desenvolvido por González e Carvajal (2002). Quando o resultado do IGS for menor ou igual a 50%, a atividade apresenta-se no campo da insustentabilidade e será mais sustentável próximo a 100%. Os resultados na dimensão institucional apresentaram índices de 37%, na dimensão social em 58%, ambos considerados graus ruins de sustentabilidade. Na dimensão ambiental índices de 60%, ambos considerados graus bons para a sustentabilidade e, finalmente, a dimensão econômica com grau 36%, em nível ruim para a sustentabilidade. O IGS calculado foi de 47,74% o que não pode ser considerado sustentável. Desta forma, os resultados obtidos identificam que a produção bovina leiteira, de Pombal, necessita de atenção, com mais políticas públicas para o setor, não apenas no aspecto econômico, mas também nas dimensões sociais e ambientais, possibilitando melhorias na qualidade de vida dos envolvidos, como também, na conservação dos recursos naturais. / Brazil has one of the largest dairy cattle herds in the world. However, despite being among the major world producers of milk, the national dairy industry is quite heterogeneous. Part of some regions such as the Brazilian Northeast, is still under development to meet the standards of quality and quantity and get the competitive market, such as the municipality of Pombal, to be located in the backlands of Paraiba, the present study area, which is recognized statewide for its dairy potential. In this context, this study aims to make an analysis of the sustainability of dairy cattle of Pombal, in their institutional (technological), social, economic and environmental aspects. For the execution of this study, site visits and application of semi-structured questionnaires, 50 dairy farmers, belonging to thirty- two rural areas of this municipality were necessary. From the responses, indicators were calculated using the method of UNDP / UN (1998), whose results ranged from 0 (zero) to 100 (one hundred) and were divided into four grades of sustainabilities: critical, poor , good or excellent. Then applied to the mathematical formula called GSI (Global Sustainability Index) developed by González and Carvajal (2002 ). When the result of the IGS is less than or equal to 50%, the activity is presented in the field of unsustainability will be more sustainable and close to 100% . The results presented in the institutional dimension ratios of 37%, the social dimension in 58%, both considered bad grades sustainability. In the environmental dimension ratios of 60%, both considered good grades for sustainability and ultimately the economic dimension with grade 36% in bad for the sustainability level . The calculated IGS was 47.74% which can not be considered sustainable. Thus, the results identify that the dairy cattle production, Pombal, needs attention, most public policies for the sector , not only in economics but also in social and environmental dimensions, enabling improvements in the quality of life of those involved, but also to conserve natural resources.