FDTD is an electromagnetic field computation method with the ability of considering circuit elements. Traditional lump element method is insufficient for simulating circuit. In this thesis, we use equivalent source method to combine non-linear circuit elements like active devices into the FDTD simulation. The advantages of this is powerful and time-saving. The accuracy of this method is checked of transmission line driving by CMOS circuits. By employing this method, we find that it will increase EMI phenomenon by strengthening current of driving load, and the load of coupling line will affect noise due to impedance mismatch.

The FDTD method is a numerical method that uses the second-order central-difference method to discrete the Maxwell¡¦s equations in differential form, and positioning electromagnetic field in space grids and time grids. It is applied to analyze many electromagnetic problems in time domain. In the thesis, we applied FDTD methods to solve EMC/EMI problems like the interference to a mixer from an antenna, and the packaging effects to a small signal microwave amplifier and so on. Therefore, we applied equivalent current source approach to simulate each microwave elements at first. And, we extend the approach to field of EMC/EMI. researching the advantages of FDTD methods in Full-Wave analysis.

Tissue equivalent proportional counters are frequently used to measure dose and dose equivalent in mixed radiation fields that include neutrons; however, detectors simulating sites 1?m in diameter underestimate the quality factor, Q, for low energy neutrons because the recoil protons do not cross the detectors. Proportional counters simulating different site-sizes can be used to get a better neutron dose equivalent measurement since the range and stopping power of protons generated by neutrons in the tissue-equivalent walls depend on the energy of the primary neutrons. The differences in the spectra measured by different size detectors will provide additional information on the incident neutron energy. Monte Carlo N-particle extended (MCNPX) code was used to simulate neutron transportation in proportional counters of different simulated tissue diameter. These Monte Carlo results were tested using two solid walled tissue equivalent proportional counters, 2mm and 10mm in diameter, simulating tissue volumes 0.1?m and 0.5?m in diameter, housed in a single vacuum chamber. Both detectors are built with 3mm thick tissue equivalent plastic (A-150) walls and propane gas inside for dose measurement. Using these two detectors, the spectra were compared to determine the underestimation of y for large detector, and thereby obtain more information of the incident neutron particles. Based on the MCNPX simulation and experimental results, we can see that the smaller detector produces a larger average lineal energy than the larger detector, which means the larger detector (0.5?m diameter tissue equivalent size) underestimates the Q value for the low energy neutron, therefore underestimates the effective dose. These results confirm the results of the typical analysis of lineal energy as a function of site size.

The thesis proposes a hybrid broadband equivalent model extraction method, and our goal is to combine via structure and irregular transmission line in print circuit board for extraction of broadband SPICE-compatible model by using the time domain algorithm and full wave simulation in frequency domain, respectively. We can construct broadband SPICE-compatible macro-model scalable library with two kind of different extraction methods, tow kind of extraction of equivalent model can construct the circuit structure for designer demand. Every modules of the broadband macro model of the two extraction models are represented by the optimum pole-residue forms. Using a systematic lumped-model extraction technique, all the optimum pole-residue rational functions can be transfered into a corresponding lumped circuit model. The accuracy of Extraction of Broadband Equivalent Models is demonstrated in frequency -domain responses compared with the 3D-FDTD or HFSS simulation. In addition, the extraction model can simulate in commercial tools effectively, ex: Hspice¡BADS. Even the model can simulate signal integrality and power integrality in Hspice or ADS.

Nitroacrylates are stable, crystalline solids and have frequently been used in synthesis as reactive dienophiles in the Diels-Alder reaction. The regio- and diastereoselectivity of the Diels-Alder reaction is controlled by the electronic properties of the nitro group. This thesis describes work to utilise the nitro group to provide control of stereochemistry in the synthesis of natural products. The thesis begins by discussing the synthesis of nitroacrylates using both a nitro-aldol and radical based route. An investigation into their selectivity in the Diels-Alder reaction with a diverse array of dienes is discussed. As part of this investigation a large increase in diastereoselectivity was observed for the reaction of ethyl β-nitroacrylate and 1-methoxycyclohexa-1,4-diene when Lewis acids were added. The origin of this selectivity is unknown and similar dienes show only a modest increase in selectivity on addition of ZnCl(_2).An application of the resultant adducts has been demonstrated in the synthesis of a simple bicyclic P-amino acid and then subsequendy applied to the diastereoselective synthesis of chorismate-based P-amino acids (25*, 3S*)-DHAA and the antibiotic oryzoxymycin. The key steps involve a base-mediated ring-opening reaction of the 7-oxa-bicyclo[2,2,l]hept-5-ene and a CsF mediated coupling of the lactate moiety. The progress toward the synthesis of a related anthranilate synthase inhibitor is also discussed. Finally, in the context of a synthesis of the structurally unique diterpene Vinigrol 1 we have shown that nitroacrylates can be employed as substituted ketene equivalents in the formation of cyclic alpha-chiral ketones.

abstract: Optical Instrument Transformers (OIT) have been developed as an alternative to traditional instrument transformers (IT). The question "Can optical instrument transformers substitute for the traditional transformers?" is the main motivation of this study. Finding the answer for this question and developing complete models are the contributions of this work. Dedicated test facilities are developed so that the steady state and transient performances of analog outputs of a magnetic current transformer (CT) and a magnetic voltage transformer (VT) are compared with that of an optical current transformer (OCT) and an optical voltage transformer (OVT) respectively. Frequency response characteristics of OIT outputs are obtained. Comparison results show that OITs have a specified accuracy of 0.3% in all cases. They are linear, and DC offset does not saturate the systems. The OIT output signal has a 40~60 μs time delay, but this is typically less than the equivalent phase difference permitted by the IEEE and IEC standards for protection applications. Analog outputs have significantly higher bandwidths (adjustable to 20 to 40 kHz) than the IT. The digital output signal bandwidth (2.4 kHz) of an OCT is significantly lower than the analog signal bandwidth (20 kHz) due to the sampling rates involved. The OIT analog outputs may have significant white noise of 6%, but the white noise does not affect accuracy or protection performance. Temperatures up to 50oC do not adversely affect the performance of the OITs. Three types of models are developed for analog outputs: analog, digital, and complete models. Well-known mathematical methods, such as network synthesis and Jones calculus methods are applied. The developed models are compared with experiment results and are verified with simulation programs. Results show less than 1.5% for OCT and 2% for OVT difference and that the developed models can be used for power system simulations and the method used for the development can be used to develop models for all other brands of optical systems. The communication and data transfer between the all-digital protection systems is investigated by developing a test facility for all digital protection systems. Test results show that different manufacturers' relays and transformers based on the IEC standard can serve the power system successfully. / Dissertation/Thesis / Ph.D. Electrical Engineering 2010

abstract: Due to restructuring and open access to the transmission system, modern electric power systems are being operated closer to their operational limits. Additionally, the secure operational limits of modern power systems have become increasingly difficult to evaluate as the scale of the network and the number of transactions between utilities increase. To account for these challenges associated with the rapid expansion of electric power systems, dynamic equivalents have been widely applied for the purpose of reducing the computational effort of simulation-based transient security assessment. Dynamic equivalents are commonly developed using a coherency-based approach in which a retained area and an external area are first demarcated. Then the coherent generators in the external area are aggregated and replaced by equivalenced models, followed by network reduction and load aggregation. In this process, an improperly defined retained area can result in detrimental impacts on the effectiveness of the equivalents in preserving the dynamic characteristics of the original unreduced system. In this dissertation, a comprehensive approach has been proposed to determine an appropriate retained area boundary by including the critical generators in the external area that are tightly coupled with the initial retained area. Further-more, a systematic approach has also been investigated to efficiently predict the variation in generator slow coherency behavior when the system operating condition is subject to change. Based on this determination, the critical generators in the external area that are tightly coherent with the generators in the initial retained area are retained, resulting in a new retained area boundary. Finally, a novel hybrid dynamic equivalent, consisting of both a coherency-based equivalent and an artificial neural network (ANN)-based equivalent, has been proposed and analyzed. The ANN-based equivalent complements the coherency-based equivalent at all the retained area boundary buses, and it is designed to compensate for the discrepancy between the full system and the conventional coherency-based equivalent. The approaches developed have been validated on a large portion of the Western Electricity Coordinating Council (WECC) system and on a test case including a significant portion of the eastern interconnection. / Dissertation/Thesis / Ph.D. Electrical Engineering 2011

This dissertation deals with the noise emissions caused due pig fattening. The theoretical part contains a description of the economic importance of pig farming in the Czech Republic. It also describes the noise and its impact on the environment, noise effects on humans and animals, using best available technologies (BAT) to reduce it in pig farms and includes other sanitary limits. The practical part describes the structures of pig breeding, measuring instruments and the methods which are used for calculating the measurement of the noise. The obtained data are shown in the graphs and by each measurement was performed statistical analysis. In another point are the result values compared with sanitary limits.

Equivalent temperature is an atmospheric variable that combines both dry static energy (associated with temperature) and moist static energy (associated with moisture). Changes in equivalent temperature therefore reflect changes in total surface energy content. This research is concerned with quantifying trends in equivalent temperature and its subcomponents at 8 National Weather Service (NWS) 1st Order stations in the central USA. Data quality control was conducted and time series and time-varying percentile trends of maximum and minimum equivalent temperature and its subcomponents were developed for each of the stations on the daily scale; along with a heat wave trend analysis. It was found that there is an overall positive trend in lower tropospheric heat content over the last 60 years--driven primarily by increases in low-level moisture. The largest changes in equivalent temperature occurred during spring and fall, with some of these trends as large as 5 deg. Celsius/50 years. Furthermore, it was found that there is an increase in the number of high humidity heat wave events and that these types of events are more frequent than low humidity events; which saw a slight decrease in frequency. Interestingly, one station (Nashville, TN) exhibited a slight negative trend in equivalent temperature maxima, which may be due to synoptic-scale influence such as the Great Plains low-level jet. The results demonstrate that equivalent temperature provides a different perspective than temperature for assessing regional climate change.

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