MATLAB GUI Based Educational Simulation Tool Box for Power Analysis

One of the most important and complex tasks in power engineering is the analysis of power systems under fault conditions. The detection and analysis of these faults are important to guarantee that the dependability and stability of the power system does not decline as a result of a critical event such as a fault. This thesis will conduct research on how a power system under fault conditions behaves and will examine the various scenarios of faults such as three-phase, single line-to-ground, line-to-line, and double line-to-ground faults. A simplified method based on symmetrical components is used to construct the mathematical models that calculate the fault currents and the fault voltages. A MATLAB/ Graphical User Interface based simulation tool has been developed to use as an educational tool and these models have been integrated into a MATLAB/ Graphical User Interface. This GUI has an option to enter input data and select the fault type and will provide the calculation of three-phase, single line-to-ground, line-to-line, and double line-to-ground faults on power systems. These calculated fault currents and voltages display on a GUI screen along with the time variations of signal. A so called Educational resources zone was also added with various text from literature and videos on power system analysis so that the students can have a better understanding. In this way, the developed MATLAB GUI simulation tool can be used by students to check the accuracy of the hand calculations and to observe the transient wave forms of fault current and voltages

Measurements of Magnetic Field Penetration of Materials for Superconducting Radiofrequency Cavities

Superconducting Radio Frequency (SRF) cavities used in particle accelerators are typically formed from or coated with superconducting materials. Currently high purity niobium is the material of choice for SRF cavities which have been optimized to operate near their theoretical field limits. This brings about the need for significant R&D efforts to develop next generation superconducting materials which could outperform Nb and keep up with the demands of new accelerator facilities. To achieve high quality factors and accelerating gradients, the cavity material should be able to remain in the superconducting Meissner state under high RF magnetic field without penetration of quantized magnetic vortices through the cavity wall. Therefore, the magnetic field at which vortices penetrate in a superconductor is one of the key parameters of merit of SRF cavities. Techniques to measure the onset of magnetic field penetration on thin film samples need to be developed to mitigate the issues with the conventional magnetometry measurements which are strongly influenced by the film orientation and shape and edge effects. The applied magnetic field is also needed to be parallel to the one side of the superconductor to resemble the magnetic field profile at the surface of the SRF cavities operating at fundamental accelerating mode. In this work we report the development of an experimental setup called Magnetic Field Penetration (MFP) magnetometer to measure the field of full flux penetration through bulk, thin films and multilayered superconductors. Our system combines a small superconducting solenoid which can generate the magnetic field up to 500 mT at the sample surface and three Hall probes to detect the full flux penetration through the planner superconductor with 2 inch diameter. This setup was used to study alternative materials which could potentially outperform niobium, as well as SIS multilayer coatings on niobium

BODIPY-based Red Sensitizers for Near-infrared Emission of Lanthanide Complexes

During the past 20 years there has been a remarkable growth in the use of the fluorescence technique in biological studies. Fluorescence and time-resolved fluorescence spectroscopy are considered primary research tools in the field of biochemistry. Currently, fluorescence spectroscopy is a dominant methodology and used widely in biotechnology and medical diagnosis process. One impediment in using fluorescent probes is the fluorescence of biological substrates and fluorescence of diagnostic probes are significantly overlapped, and it decreases the detection sensitivity. Also, commercially available probes require UV or near-UV light excitation, causing severe degradation of biological substrates. Near-infrared emitting lanthanide complexes can overcome this problem by enhancing the detection sensitivity. BODIPY dyes have gained significant attention in application of fluorescence sensing and imaging in recent years, because they possess many desirable properties such as high extinction coefficient, narrow absorption and emission bands, high quantum yield and low photobleaching effect. One strategy to overcome the low detection sensitivity of fluorescent dyes is; shift the absorbance and emission of BODIPY precursor towards the longer wavelength regions by increasing the π-conjugation of a sensitizer. BODIPY molecules are especially responsive to this method. Four BODIPY-based ligands and four Yb(III) lanthanide complexes have been synthesized, which bear 5-ethynyl-5\u27-methyl-2,2\u27-N-bipyridine ligand-binding-group (LBG) in the C2 position and either a hydrogen (PH1), an iodine (PH2), an 4-ethynylbenzoic acid (PH3) or an 1-ethynyl-4-isothiocyanatobenzene (PH4) groups in its C6 position. This study focused to test their ability to sensitize the luminescence of NIR emission of Yb(III) ion. All ligands exhibited broader absorption with high molar absorption coefficients. The PH3 ligand displays maximum absorption at (573 nm). The typical metal centered luminescence is detected at 980 nm for Yb(III) upon excitation at their maximal absorption position in the visible region. All complexes showed similar lifetimes in the NIR region (10.9 - 11.1 μs), which corresponds to emission yield of 0.09%. This study demonstrates that the BODIPY-bipyridine ligands are adequate for sensitizing the luminescence of NIR-emitting lanthanide ions, allowing excitation wavelengths extending into the red region of the visible spectrum

Strategies to Improve Calf Performance: Improving Water Quality, Feeding Microbially-enhanced Soy Protein, and Supplementing Condensed Whey Solubles

Six experiments were conducted for this dissertation research to evaluate strategies to improve growth performance and health of calves. Growth performance, nutrient utilization, and health effects were evaluated when calves were offered water treated with reverse osmosis system (RW), fed starter pellets supplemented with microbially-enhanced soy protein (MSP) or supplemented condensed whey solubles (CWS). The first two experiments were conducted to determine drinking preference, growth performance, and health of dairy calves offered RW or by a municipal water treatment plant (MW), compared with local untreated well water (WW). First a sequential elimination study was conducted to observed drinking preference of calves given RW, MW and WW. Greater preference was observed calves fed RW and least was WW, with RW slightly preferred over MW. The second study was conducted to determine the effects of drinking RW versus MW on the growth performance and general health of calves. Total DMI and gain: feed, increased more over time for RW than MW. Water intakes were less in RW than MW, indicating more efficient water use. Frame growth, BW, nutrient utilization and blood metabolites were not different between treatments. Fecal scores tended to be less in calves on RW, with an interaction over time. The third and fourth experiments were conducted to determine effects of feeding calves starter pellets with MSP compared to soybean meal (SBM) with different milk replacers (MR) or with pasteurized milk. The third experiment demonstrated calves fed MSP at 23% of DM inclusion in starter pellets improved feed efficiency and maintained growth performance depending on MR. Next the fourth experiment was conducted to evaluate calves fed starter pellets with less inclusion of MSP (8% of DM basis) with pasteurized milk on growth performance and health. Calves fed MSP had greater DMI, and β-hydroxy butyrate (BHB) with similar BW and frame measurements between treatments. During the fifth and sixth experiments growth performance, nutrient utilization, and health were determine when calves were fed milk and starter pellets supplemented with CWS. In the fifth experiment during pre-weaning CWS were fed with milk and post-weaning CWS was top-dressed on starter pellets. Supplementing CWS improved starter intake, post-weaning BW, plasma concentrations of BHB, fecal scores, while maintaining frame growth. The sixth experiment was conducted on large commercial calf ranch to determine the effect of supplementing CWS on starter grain mix at low (CWSL) and high (CWSH) inclusion amounts throughout the first 12 wk of life. The DMI, BW, plasma concentration of BHB, and body condition scores were improved in calves fed CWSL while maintaining frame measurements and fecal and health scores. Improved water quality, feeding MSP, or supplementing CWS improved calf growth performance, nutrient utilization, and general health and offer new options for producers to improve calf performance

BODIPY-based Red Sensitizers for Near-infrared Emission of Lanthanide Complexes

During the past 20 years there has been a remarkable growth in the use of the fluorescence technique in biological studies. Fluorescence and time-resolved fluorescence spectroscopy are considered primary research tools in the field of biochemistry. Currently, fluorescence spectroscopy is a dominant methodology and used widely in biotechnology and medical diagnosis process. One impediment in using fluorescent probes is the fluorescence of biological substrates and fluorescence of diagnostic probes are significantly overlapped, and it decreases the detection sensitivity. Also, commercially available probes require UV or near-UV light excitation, causing severe degradation of biological substrates. Near-infrared emitting lanthanide complexes can overcome this problem by enhancing the detection sensitivity. BODIPY dyes have gained significant attention in application of fluorescence sensing and imaging in recent years, because they possess many desirable properties such as high extinction coefficient, narrow absorption and emission bands, high quantum yield and low photobleaching effect. One strategy to overcome the low detection sensitivity of fluorescent dyes is; shift the absorbance and emission of BODIPY precursor towards the longer wavelength regions by increasing the π-conjugation of a sensitizer. BODIPY molecules are especially responsive to this method. Four BODIPY-based ligands and four Yb(III) lanthanide complexes have been synthesized, which bear 5-ethynyl-5\u27-methyl-2,2\u27-N-bipyridine ligand-binding-group (LBG) in the C2 position and either a hydrogen (PH1), an iodine (PH2), an 4-ethynylbenzoic acid (PH3) or an 1-ethynyl-4-isothiocyanatobenzene (PH4) groups in its C6 position. This study focused to test their ability to sensitize the luminescence of NIR emission of Yb(III) ion. All ligands exhibited broader absorption with high molar absorption coefficients. The PH3 ligand displays maximum absorption at (573 nm). The typical metal centered luminescence is detected at 980 nm for Yb(III) upon excitation at their maximal absorption position in the visible region. All complexes showed similar lifetimes in the NIR region (10.9 - 11.1 μs), which corresponds to emission yield of 0.09%. This study demonstrates that the BODIPY-bipyridine ligands are adequate for sensitizing the luminescence of NIR-emitting lanthanide ions, allowing excitation wavelengths extending into the red region of the visible spectrum

Growth and properties of metal-on-metal nanostructures: Ag on Cu(110) and Co on Ag(110)

Heteroepitaxial nanostructures have a diverse array of applications and show novel phenomena that arise from the exotic physics exhibited in reduced dimensions. We have investigated two nano-structured systems in order to gain insights into the dynamics of their nucleation, growth and have observed striking differences, due in part to a competition between lattice strain, surface and interfacial free energies. When Ag is deposited on clean, single-crystal Cu(110), it initially wets the surface with a (111) monolayer, and spontaneously nucleates nanowires as the coverage is increased. The nanowires nucleate at defects and step edges and grow aligned along the [1–10] direction. In the initial stages of growth, they extend from step edges onto the lower terrace but as their height increases they extend along on the upper terrace as well, growing ~10nm wide and ~2.5nm high. The growth rate for any particular nanowire is found to be nearly independent of its separation from nearby nanowires, indicating that surface diffusion is facile. At elevated temperature (T \u3e ~700K) and in the absence of the Ag flux, the nanowires Ostwald ripen into larger nanobars with widths of 400-800nm where surface adatom diffusion results in the disappearance of smaller nanowires. Collective excitation of the electron gas within these nanowires reflects their distinct quasi-1D structural anisotropy. The dispersion of Ag plasmons has been obtained and along the nanowire axis we find that the plasmon dispersion is linear with momentum transfer and remains constant beyond 0.3/Å. No dispersion is found for the plasmon perpendicular to the nanowire axis, reminiscent of the localized Mie resonance found in clusters. In distinct contrast to Ag grown on Cu(110), where the surface free energy of Ag is smaller than that of the substrate, the structures formed when Co is grown on Ag(110) arise due to the larger surface free energy of the adsorbate. Co prefers to cluster, and grows in the form of nanodots ~0.6nm high and ~2.5nm wide, embedded in Ag to minimize its energy. Upon annealing the Co nanodots sinter and agglomerate and into super-clusters while a portion migrates into the Ag bulk

Detection of Vibrio vulnificus by direct colony immunoblot

Vibrio vulnificus (Vv) is a natural occurring bacterium of world wide estuarine environments, which concentrate on filter feeding shellfish. Under cooked seafood contaminated with this pathogen is a leading cause of 95% of seafood-related, foodborne deaths. The development of a rapid, reliable and user-friendly method for Vv enumeration would help to reduce mortality rate. A direct colony immunoblot (DCI) method was developed and used as a rapid enumeration with high sensitivity and the specificity. This method was optimized using Vv agar plates incubated for 16 h at 35 °C. Colonies were transferred from incubated plates to polyvinylidene fluoride (PVDF) membranes and treated with rabbit anti–flagellar Vv antibodies for 1 h, then washed 3 times. The membranes were then incubated with peroxidase-conjugated goat anti-rabbit IgG for 1 h, and washed 3 times. Finally, the color development mixture was added (Tris buffer, 3, 3’-diaminobenzidine, NiCl2 and H2O2) for 5 min. Positive colonies produced a purple color. Total time duration for enumeration of Vv by the DCI was 3.5 h. The DCI method was compared with the FDA recommended DNA probe hybridization (DNAH) method (6-10 h) and most probable number MPN method (50 h) for enumeration of naturally occurring Vv in oysters. There was no significant difference between the DCI and DNAH methods at 0h, 4h, 8h, 12h and 24h, with both methods having Vv counts of about 2.90 Log CFU/g. By day 7 there was a significance difference between the two methods, with the DNAH exhibiting higher Vv counts (2.62 Log CFU/g) compared to the DCI (2.22 Log CFU/g). By 14 days the counts for both methods were not significantly different from each other (1 Log CFU/g). The DCI method exhibited comparable Vv counts in raw oysters compared with those of the DNAH method except for day 7, which may be due to false positive colonies detected by the DNAH method. The DCI could be a more reliable, inexpensive, rapid and user-friendly method for enumeration of Vv in raw oysters. This could possibly be used as a rapid enumeration method by regulatory agencies or the seafood industry

Effect of Resistant Starch on Microbial Content of the Intestinal Tract

Resistant starch (RS) increases beneficial gastro-intestinal bacterial populations simultaneously increasing short-chain fatty acids (SCFA) such as butyrate. Butyrate acts as energy source for epithelial cells of colonic mucosa which stimulates intestinal cell proliferation and has been implicated as important in reducing obesity, diabetes and cancer. The Lactobacillus spp, Bifidobacterium spp, Bacteroides thetaiotaomicron, Clostridium cluster IV and Clostridium cluster XIV are mainly involved in the production of butyrate by fermenting RS in the large intestine. With age there is a decline in these gut bacteria, but in the present study RS and diet restriction both enhanced the bacteria involved in butyrate production. In addition, RS reduces body fat in some types of obesity but not all. For example, RS reduced body fat in an endocrine model of obesity caused by ovariectomy (OV). In this study RS significantly increase bacterial populations involve in butyrate production. However, in high fat diet induced obesity the results were different. The high fat diet (41% dietary energy) prevented fermentation of RS and reduced bacterial populations in the ceca compared to a low fat diet (18% dietary energy). The RS failed to reduce obesity in these rodents fed a high fat diet while increasing Bacteroides group population. To follow up these studies and determine if type of fat was important in directly altering gut fermentation, an in-vitro fermentation model of rat large intestine was used. Both Corn oil and Lard reduced bacterial populations which are involved in fermentation of RS. However, if the fat used was fish oil there were no negative effects on the fermentation of RS or the bacterial population. These studies illustrate the need to control the type of fat when studying the effects of prebiotics or other sources of resistant starch. With the age Bifidobacterium spp, Bacteroides spp, Clostridium cluster IV and Clostridium cluster XIV decreased both calorie restricted diet and RS diets were able to improve these bacterial populations

Probing the large-scale galaxy density and peculiar velocity fields

This thesis focuses on constraining the linear redshift distortion parameter β, which is a critical variable in reconstructing the peculiar velocity field of the Local Universe and probing information of the distribution on dark matter. We used mock data samples of peculiar velocity fields that aim to mimic the next generation of galaxy peculiar velocity surveys such may become feasible for SKA and its precursors. The smoothed IRAS PSCz peculiar velocity field [Branchini et al., 1999] was used to generate the mock data samples, where the true value of β was considered to be 0.5 throughout this work (i.e. β(true) = 0.5). The study was carried out considering two methods. First, we applied the χ2 hypothesis test by comparing the observed and predicted peculiar velocity fields to constrain β from the mock peculiar velocity fields. In this case, the traditional distance indicators such as SNIa, TF and recently introduced gravitational wave standard sirens were considered. The distance scatter of each indicator was taken from literature and scatter in the predicted peculiar velocity (σv) was considered to be a variable. The best-fit value of β for the peculiar velocity models show a good agreement with β(true) when σv < 150 km s(−1) . Our calculations implied that, in order to fully exploit the potential of future improvement in the precision of β estimates, it is important also to improve the accuracy of the reconstructed peculiar velocity field predicted from all-sky redshift surveys. The second method is the ROBUST method originally introduced by Rauzy & Hendry for fitting peculiar velocity fields. The ROBUST method use the luminosity functions of the mock galaxies as the distance indicators, where the LF assumed to be independent of the spatial position of the galaxies. Our results are in a good agreement with β(true)= 0.5, where the best fit values of the peculiar velocity models always centred around 0.5. Our results demonstrate the potential of the method, even in cases where the luminosity function is rather broad, provided it can be applied to sufficiently large peculiar velocity surveys - such as those which may be anticipated from e.g. the 6dF and WALLABY surveys in the relatively near future