Nowadays, electronics has really flourished with the rapid progress in science and technology. Besides being light and efficient of the products, digitalization and faster speed are also required which make the problem of EMI, electromagnetic interference, become more serious. Newer power supplies using switching technology become smaller and smaller. However, they also produce EMI problems that need to be considered. In this thesis, we only address the conducted EMI. Generally, the noise is suppressed by adding a filter at the power-line end. Hence, the EMI filter plays an important role to the solution of conducted emission. The particular filter is related to the type of the conducted emission, including common-mode and differential-mode. As a result, it is a great help for an engineer to be able to separate the noise. There are several noise separators in the present days. We propose new separators, which are capable of detect common-mode and differential-mode separately. Our separators are low-cost, easily manufactured and are able to give exact noise readings without adjustment. Incorporating the known methods of filter design and combing programming measurement the filter design can be made automatic. One approach makes use of the spectrum analyzer, which is considered to be a relatively expensive instrument. We also propose another approach using oscilloscope. The time-domain measurement is performed and transformed into frequency domain using FFT. A realistic design example is shown to give satisfactory results.

This thesis presents the conducted electro-magnetic interference (EMI) prediction results for a continuous conduction mode (CCM) power factor correction (PFC) converter as well as the theoretical analysis for the noise generation and propagation mechanisms. In this thesis, multiple modeling and characterization techniques in the medium and high frequency ranges are developed for the circuit components that are important contributors to the EMI noise, so that a detailed simulation circuit for EMI prediction can be constructed. The conducted EMI noise prediction from the simulation circuit closely matches the measurement results obtained by a spectrum analyzer. Simulation time step and noise separator selection are two important issues for the noise simulation and measurement. These two issues are addressed and the solutions are proposed. The conducted EMI generation and propagation mechanisms are analyzed in a systematic way. Two loop models are proposed to explain the EMI noise behavior. The effects of the PFC inductor, the parasitic capacitance between the device and the heatsink, the rising/falling time of the MOSFET VDS voltage, and the input wires are studied to verify the validity of the loop models. / Master of Science

In our society, police officers have been called upon to ensure compliance with the law and preserve social order. To complete this task, there are situations in which officers must use force. Since they must use force in some situations and because not every citizen is cooperative with the police, they are at risk for injury. Multiple studies have shown that tasers are beneficial to police officers in many ways, including a reduction in officer injuries. Most studies, however, observed injuries in only a few departments before and after implementation. This study examines whether or not agencies that authorize the use of tasers have lower injury rates compared to agencies that do not authorize the use of tasers in a large sample. This will be done through a cross-sectional research design using secondary data analysis. The data for this study comes from two sources, the 2008 Uniform Crime Reports and the 2007 Law Enforcement Management Administrative Statistics (LEMAS) survey. Results showed that the authorization of tasers by police departments was not a significant predictor of police injury rates. Although it is not a significant predictor in this study, an argument can still be made that tasers are effective at reducing injuries to police officers.

In his thesis, CONDUCTED EMC MODELLING IN MODERN DC-DC POWER CONVERTERS, the conducted electromagnetic effects of high-density high-switching frequency modern power converters are studied. The noise source and noise path were modelled and the results calibrated to accredited noise levels. A VHF frequency model was developed and verified using different analysis packages and compared for accuracy, affordability and ease of use. Noise modes were separated and verified for accuracy. The mechanisms of the noise modes were studied and noise mitigation techniques presented. / Thesis (PhD)--University of Pretoria, 2017. / Electrical, Electronic and Computer Engineering / PhD / Unrestricted

Measurement-based behavioral electromagnetic interference (EMI) models have been shown earlier to accurately capture the EMI behavior of switched power converters. These models are compact, linear, and run in frequency domain, enabling faster and more stable simulations compared to the detailed lumped circuit models. So far, the behavioral EMI modeling techniques are developed and applied to the converter's input side only. The resulting models are therefore referred to as "terminated EMI models". Under the condition that the output side of the converter remains fixed, these models can predict the input side EMI for any change in the impedance of the input side network. However, any change at the output side would require re-extraction of the behavioral model. Thus the terminated EMI models are incapable of predicting the change in the input side EMI due to changes at the output side of the converter or vice versa. The above mentioned limitation has been overcome by an "un-terminated EMI model" proposed in this dissertation. Un-terminated EMI models are developed here to predict both the common-mode (CM) and the differential (DM) noise currents at the input and the output sides of a motor-drive system. The modeling procedure itself has been simplified and now requires fewer measurements and results in less noise in the identified model parameters. Both CM and DM models are then combined to predict the total noise in the motor drive system. All models are validated by experiments and their limitations identified. A significant portion of this dissertation is then devoted to the application of behavioral EMI models in the design of EMI filters. Comprehensive design procedures are developed for both DM and CM filters in a motor-drive system. The filters designed using the proposed methods are experimentally shown to satisfy the DO-160 conducted emissions standards. The dissertation ends with a summary of contributions, limitations, and some future research directions. / Ph. D.

The reclamation of muck soil is a new development in the state of Utah. Knowledge concerning the various properties and requirements of the newly-drained area in Sanpete County, Utah, is extremely limited. A need for fundamental information concerning this type of soil was the basis for the establishment of an experimental farm in this region. The fact that most organic soils respond to mineral fertilizers soon after they have been reclaimed was an important reason for starting fertilizer work on this soil as soon as it was possible to do so. This thesis reports some of the fertilizer work being conducted on the farm. The soil on which the experimental work is being conducted seems to be fairly representative of an area of about 6500 acres located near the south end of the Sanpete Valley. The muck soil has been developed here in what was originally a shallow lake, with an impervious blue clay as the bottom. The soil was formed by the growth of marsh plants, the remains of which have accumulated and have been preserved in the water. From the time the valley was settled with white people up until 1926, the area had been used for the production of native hay and for pasture. The native sedge sod was first broken up in this region in the fall of 1926. The drainage of the area was started in the fall of 1925 and consisted of constructing canals around the project to control spring flood water. A central drain was installed, through the bottom of the area, with sufficient small laterals to properly drain the soil. The development of the area for at least two years after breaking the sod has consisted of pulverizing the coarse sod, allowing sufficient time for the roots to decay, so that crops could be grown.

The advent of wide-bandgap (WBG) devices like silicon carbide (SiC) MOSFETs has resulted in a paradigm shift toward high-density and high-efficiency integration of power electronics systems. This being the result of relatively high switching frequencies (>10 kHz) compared to conventional Si IGBT counterparts, which reportedly can minimize the size of passive components such as DC-link capacitors and line harmonic filters. Unfortunately, with faster switching speeds and high slew rates, the common-mode (CM) and differential-mode (DM) conducted emissions interference (EMI) noise is worsened. The effects are manifested at the utility interface with grid-tied applications (three-phase rectifiers or back-to-back converters) in the form of high CM and DM emissions, total harmonic distortion (THD) and current harmonics. While at the motor end, long cable and bearing/leakage current effects are prevalent. As such, typically bulky passive filters are recommended to comply with industry regulations and allow safe and reliable system operation, which can be detrimental on the overall system power density. Hence, it is imperative to minimize the filter volume/weight contribution to fully utilize the benefits of WBG power converters. As an added feature, modular filter building block (FBB) configurations inspired by the building block nature of power electronics converters are needed to address scalability to higher power levels (through interleaving or paralleling) without the need for significant filter redesign. As such, for grid-tied applications (AC-DC converters), the interleaving of parallel converters adopted to achieve superior harmonic attenuation for grid-side currents at the expense of low harmonic filter volume. Therefore, interleaved converters are explored in Chapters 2 and 3. However, to block inter-channel circulation, additional use of coupled inductors (CI) can outweigh the benefits of interleaving. Therefore, modular FBB architectures with unique methods to handle circulating currents are proposed. At the same time, the FBB is designed to meet power quality and EMI limits for any given number of channels, up to the maximum number of channels, N, allowed at the point of common coupling (PCC). Consequently, a qualitative and quantitative comparison of FBB candidates is performed, and the indirectly coupled FBB using a secondary loop interconnection is proposed as a viable modular FBB candidate. Correspondingly, for DC-AC inverters, modular filters can be realized using a masked impedance and decoupling approach. The test case being a DC-fed motor drive for aircraft propulsion systems. Techniques, such as optimized parallel RC dampers to reduce the peak bearing current and CM/DM magnetic integration of a DC side filter with an embedded DC current sensor and embedded decoupling path with gate driver for high frequency commutation, are implemented to reduce the overall weight of the system. The challenges with low temperature rise margin due to high ambient temperature and low peak Partial Discharge Inception Voltage (PDIV) are addressed. In addition, a novel pulse with modulation (PWM) scheme is proposed to further enhance the bandwidth of the proposed AC filter, specifically targeted to reduce the peak bearing current and improve the specific power and motor lifetime. A negative consequence of high-density filter integration is the impact of self and mutual parasitic couplings of filter sub-components on filter attenuation, which is studied on a back-to-back converter system (AC-AC). Simplified lumped models that are representative of the high frequency filter behavior are developed to desensitize the impact of individual filter sub-components. Thereafter, unique winding and placement techniques are proposed to compensate for the impact of self and mutual parasitic couplings on the noise spectrum. Overall, this work presents potential FBB topologies for varying modes of power conversion (AC-DC, DC-AC, and AC-AC), ultimately aimed at reducing the volume/weight of the system. Methods to minimize the passive component volume/weight from the point of view of topology, magnetic integration, and PWM techniques are discussed, while the implications of a high-density integration at high frequency is presented. Generalized practical design guidelines are formulated to aid in accurate high-density filter design for WBG converters. / Doctor of Philosophy / With the ever-increasing use of switching converters, either AC-DC, DC-AC, or DC-DC converters, electromagnetic interference issues can affect the overall system performance, which necessitates the use of filters. This is especially true with more and more point-of-load applications (parallel converters in charging stations, industries, and residential loads), distributed energy sources (solar power, wind power, and battery storage systems), and primary sources (power plants) being integrated together into a super grid. Similarly, transportation applications (electric vehicles, more-electric aircrafts) demand strict filtering requirements, due to the prime importance of reliability. Therefore, three-phase power quality and EMI filters are an integral part of any power conversion system, from low to high power applications. First, novel techniques to address the scalability and modularity of filters with parallel converters are considered (grid-tied application), where the benefits of interleaving and challenges in circulating current mitigation are addressed. The idea is simply to design one filter that can be used with any given number of converters running in parallel, which promotes rapid manufacturability to meet the ever-increasing demand. Thereafter a highly integrated and optimized filter structure is demonstrated for a traction inverter used in aerospace propulsion. Challenges pertaining to compact filter design are addressed, and new methods are proposed to overcome some of the critical issues that come with high-altitude operation, such as reliability, high temperature, and partial discharge-free operation. Lastly, the effect of non-idealities on filters that can lead to deteriorated performance is explored. As such, solutions to compensate for these effects are proposed and verified. Clearly, there is a need to optimize filters as well, minimizing their volume and weight contribution within a power converter. This aspect is considered throughout the work where design guidelines are proposed to optimize the given filter topology, filter parameter selection, and form factors for different applications, ranging from AC-DC converters to DC-AC traction motor drives.

Title: Administration of an immovable thing in enforcement procedure conducted by a court enforcement officer and by a licensed enforcement agent The purpose of this thesis is to analyze the administration of an immovable thing in enforcement procedure conducted by a court enforcement officer and by a licensed enforcement agent. The administration of an immovable thing is a new way of enforcement procedure, implemented to Czech legislation by amendment of the Civil Procedure Code that came into effect on 1st January. 2013. This thesis is divided into seven chapters. The first one contains just the brief overview of the main problems. Second chapter describes the enforcement procedure conducted by a court enforcement officer and by a licensed enforcement agent in general. Third chapter explains detailed characteristics of an administration of an immovable thing in enforcement procedure conducted by a court enforcement officer and by a licensed enforcement agent, its process, duration and conclusion. Fourth chapter deals with identification of main problems of an administration of an immovable thing and deals with them. Especially deals with problems regarding possible limitations of court in modification of leasing and tenure contracts. The possible use of an immovable thing by a debtor and possible...

In normal tissues, blood supply is closely matched to tissue demand for wide ranges of oxygen demand and arterial pressure. This suggests that multiple mechanisms regulate blood flow. Theoretical models can be used to analyze these interacting mechanisms. One proposed mechanism for metabolic flow regulation involves the saturation-dependent release of ATP by red blood cells, which triggers an upstream conducted response signal and arteriolar vasodilation. To analyze this mechanism, oxygen and ATP levels are calculated along a flow pathway of seven representative segments, including two vasoactive arteriolar segments. The conducted response signal is dependent on ATP concentration. Arteriolar tone depends on the conducted response signal, local wall shear stress and wall tension. Arteriolar diameters are calculated based on vascular smooth muscle mechanics. The model can account for increases in perfusion consistent with experimental findings at low and moderate oxygen consumption rates despite the opposing effects of the myogenic and shear-dependent responses. Autoregulation, the maintenance of nearly constant blood flow as arterial pressure varies, is assessed in the presence or absence of the myogenic, shear-dependent and/or metabolic responses. The model results indicate that the combined effects of myogenic and metabolic regulation overcome the vasodilatory effect of the shear-dependent response to generate autoregulatory behavior. Capillary recruitment has been shown to increase the capacity for oxygen delivery during exercise. In the model, capillary density is assumed to depend on small arteriole diameter. The model predicts a significant increase in the range over which perfusion can be regulated when recruitment is included. Oscillations in diameter and tone are predicted under certain conditions, suggesting a novel mechanism for vasomotion. The conditions that give rise to oscillations are analyzed. It is shown that the appearance of oscillations depends in a complex way on a number of system parameters. In summary, the theoretical model provides a quantitative assessment of the myogenic, shear-dependent and metabolic responses that affect blood flow regulation and identifies a role for capillary recruitment and vasomotion in the control of blood flow.

Made available in DSpace on 2017-07-10T17:37:28Z (GMT). No. of bitstreams: 1 Marcelo Angelo Campagnolo.pdf: 1417290 bytes, checksum: 5c4258f560372c956838d25a4574f101 (MD5) Previous issue date: 2008-09-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the present work was to study the effect of number of productive branches and lopping system in the development and green fig tree yield of Roxo de Valinhos in organic system. The experiment using four year-old plants, with spacing 3 x 2 m, was carried out between July/2007 and March/2008 in Quatro Pontes-PR (24o35 42 South latitude and 53o59 54 West longitude, altitude of 472 m and Cfa Koppen climate, with annual maximum medium temperature of 28.5oC and minimum of 16.6oC). The design utilized was randomized blocks with four replicates, and the treatments arranged in a 5 x 2 factorial scheme, taking as factors number of lopping (one, two, three or four, besides the control without lopping) and number of productive branches (plants conducted with six or twelve branches). In the lopping system, after the emission of the 16th leaf, the branch was blunted (removed the apical bud), being selected two sprouting by productive branches. New lopping was accomplished later on, always after the emission of the sixth leaf. In each plot, made up of three useful plants, data concerning the cropping cycles of 2007/08 were collected. Fig production under organic system is technically viable. The highest green fig yield (2,208 g planta-1) and dear productivity (3,681 Kg ha-1) was observed in the treatment which had plants conducted with twelve branches, with three lopping. There was a prolongation of the crop in the plants were made more lopping. Besides the increase in the production and prolongation of the crop, the lopping plants presented fruits with larger diameter and uniformity in relation to the witness. That uniformity allows to concentrate the crop and to decrease like this the use of cupric products / O objetivo deste trabalho foi estudar a influencia do numero de ramos produtivos e do sistema desponte sobre o desenvolvimento e producao de figos verdes Roxo de Valinhos em cultivo organico. O experimento utilizando plantas de quatro anos de idade, com espacamento 3 x 2 m, foi conduzido de julho de 2007 a marco de 2008 em Quatro Pontes-PR (24o35 42 latitude Sul e 53o59 54 longitude Oeste, altitude de 472 m e clima Cfa Koppen, com temperatura media maxima anual de 28,5oC e minima de 16,6oC). O delineamento utilizado foi em blocos ao acaso, com quatro blocos e os tratamentos arranjados em esquema fatorial 5 x 2, tomando por fatores o numero de despontes (um, dois, tres ou quatro, alem do controle sem desponte) e numero de ramos produtivos (plantas conduzidas com seis ou doze ramos). No sistema desponte, apos a emissao da 16o folha, o ramo foi despontado (gema apical removida), selecionando-se duas brotacoes por ramo produtivo. Novos despontes foram realizados posteriormente, sempre apos a emissao da sexta folha. Em cada parcela, constituida de tres plantas uteis, foram coletados dados no ciclo de producao 2007/08. A maior producao (2.208 g planta-1) e produtividade estimada (3.681 Kg ha-1) observada de figos verdes, foram obtidas quando as plantas foram conduzidas com doze ramos produtivos, efetuando-se tres despontes. Houve um prolongamento da colheita nas plantas onde se efetuaram mais despontes. Alem do aumento na producao e prolongamento da safra, as plantas despontadas apresentaram frutos com maior diametro e uniformidade em relacao a testemunha. Essa uniformidade permite concentrar a colheita e diminuir assim o uso de produtos cupricos