Thermoelectric materials convert temperature gradients into electricity and vice-versa. These materials utilize the Seebeck effect for power generation and function without moving parts and are highly reliable. The efficiency of thermoelectric devices is related to the dimensionless figure of merit for the constituent materials, defined as where S is the Seebeck coefficient, is the electrical conductivity, is the thermal conductivity and T is the temperature. Maximizing ZT is very challenging because of interdependence of parameters, for example, increasing the electrical conductivity by increasing the carrier concentration invariably lowers S and vice versa. Presently numerous thermoelectric materials are being investigated by different research groups. Despite having high thermal conductivity, half-Heusler materials are promising candidates for thermoelectric applications due to their relatively high power factor () and the ability to tune the thermal and electrical properties through substitutional doping. 2S In this research work, I have investigated the synthesis and transport properties of half Heusler series Zr 0.5Hf0.5Ni1-xPdxSn0.99Sb0.01 (0≤x≤1). Also the role of NiO and HfO2 nanoinclusions in half –Heusler matrix were studied. The half Heusler samples were prepared by solid state reaction. Resistivity, Seebeck coefficient and thermal conductivity were measured for all samples over a temperature range from room temperature to 750K. Hall effect measurements at room temperature were also performed. Addition of NiO inclusions did result in an improvement in ZT whereas addition of 3% vol HfO2 in Zr0.5Hf0.5Ni0.8Pd0.2Sn0.99Sb0.01 showed 19% improvement in ZT.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE-519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed "half-controlled" boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE–519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed “half-controlled” boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE–519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed “half-controlled” boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

The first part of this thesis presents a novel design for DRAMs to provide self-refreshing cycles which vary with temperature dynamically to reduce power dissipation in a standby mode. The proposed design monitors the data loss of a memory cell which is resulted from the leakage current, and then adjusts the period of the self-refreshing cycles. The second part presents two fast half-swing CMOS circuits for NOR-NOR PLA implementation. An additional 1/2VDD voltage source and buffering transmission gates are inserted between the NOR planes of PLAs to erase the racing problem and shorten the rise delay as well as the fall delay of the output response such that the speed is enhanced.

The purpose of this work is to evaluate the performance of a specific ac drive topology that is of current interest in industry. With the increasing pressure for compliance with IEEE-519 and other international harmonic standards, many ac drive manufacturing companies are seeking innovative and cost effective solutions for controlling the amount of harmonics produced at the point of common coupling (PCC). The proposed topology is a potential alternative to the three-phase diode bridge which is the conventional rectifier topology for non-regenerative applications. The work of this thesis explains the theory of operation, control algorithms, and potential improvement strategies for the proposed "half-controlled" boost rectifier topology. The entire ac drive system with load is then modeled and the results verified using the Simulink simulation package. It is shown that the proposed topology has several distinct advantages over a traditional diode rectifier such as improved total harmonic distortion (THD) of the current waveforms, dc bus voltage regulation, and power factor control. In addition, these advantages are created at a price point which is significantly lower than that of a conventional fully-controlled pulse-width modulated (PWM) rectifier. The main disadvantage is that the current waveforms in the utility contain even harmonics which may cause significant problems in the power system.

No description available.

Six primiparous Holstein cows were assigned to a half udder design (n=6) 40 days prior to parturition. Beginning at parturition, one udder half was milked once daily (24hr interval) and the other four times daily (6hr interval). Udder halves were biopsied at days 15, 60, 120, and 230 of lactation for mammary tissue to perform mitochondrial staining and apoptosis studies. Increasing the milking frequency from 1x to 4x elevated the 4x udder half milk yield at early (d1-45) (P<0.0001), mid (d46-150) (P<0.0001) and late (d151-230) (P<0.0001) lactation. Milk protein percent (P= 0.013), lactose percent (P=0.004) and SNF percent (P=0.006), were elevated in milk from 4x udder halves over milk from 1x udder halves. We did not detect an effect of increased milking frequency on milk fat percent (P=0.25); however, yield of all components was increased. Increased milking frequency also increased mitochondrial numbers in mammary cells from 4x udder half (P=0.002) compared to 1x. We did not detect an effect of increased milking frequency on mammary apoptosis percentage. We also did not detect a difference in the abundance of gene transcripts for SOCS1, SOCS2, SOCS3 and CIS in milk; but could find an increase in alpha-lactalbumin (P=0.04) and beta-casein (P=0.001) 4x udder half gene transcripts.

Nitric oxide (NO) has become a molecule of interest in biological research. NO is generated via the oxidation of L-arginine, by NO synthase (NOS), and plays a key role in many bioregulatory systems, including smooth muscle relaxation, platelet inhibition, neurotransmission, and immune stimulation, primarily through the formation of cGMP. N-Diazeniumdiolates (NONOates) are an interesting class of compound that can deliver NO specifically to a target site, with potential biological or therapeutic value and minimal side effects. The versatility of NONOates makes them ideal for studying NO in many different scenarios. Primary amine diazeniumdiolates such as isopropyl amine (IPA/NO) can release HNO under physiological conditions.\\Quantitative Structure Activity/Property Relationships (QSAR/QSPR) relate the structure of a compound, to a property/activity of interest ( biological activity). QSAR/QSPR studies are of great importance in drug design. Model that predict the half-lives of NONOates was built and were studied the influence of each variable on decomposition rate. External validation of this model will be made using new set of NONOates to test the Model.

No description available.