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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Evanescent wave fiber optic PH sensor in Biomedical Application

LIN, CHENG-KUO 03 September 2012 (has links)
People to feel more and more attention to health, the pursuit of high quality of life, biomedical sensing is one of the development of technology, person to understand the current state of health, currently known as blood sugar and blood pressure monitors, to track health status of the instrument is obvious too inadequate, usually go to the hospital for examination, but it is quite time-consuming, ranging from a waste of time, so the immediate biomedical optical fiber sensor to do direction. Evanescent wave ways to do research for my use of the sensing material-specific dye, sensing agent in different situations will be absorbed to change the situation, the use of sol-gel method (Sol-Gel) to coated with the specific dye, to make our fiber clothes (cladding), when the light in optical fibers, through the specific dye to change the energy of light in optical fibers.
162

Continuous fermentation of food scraps with constant pH control to produce carboxylic acids

Coleman Jr., Stanley Albert 15 May 2009 (has links)
Global energy demands combined with environmental restrictions are fueling a move to alternative energy sources. Biofuels are formed from biomass; the MixAlco process is one such method. In this work, food scraps are explored as a potential feedstock to the MixAlco process. Batch fermentation with various temperatures, buffers, and pH control methods elucidated the behavior of food scraps during fermentation. The pH and reactor configuration were limiting factors when maximizing production. A fermentor was developed and tested with constant pH control. This resulted in elevated concentration (100 g/L) and selectivity (82%) of desired products. The fermentation resulted in elevated concentrations, but low conversion of solids. The undigested material may serve as a nutrient source for fermenting lignocellulosic feedstocks. Combining various nutrient sources with lignocellulose, such as bagasse, resulted in additional production and further conversion. Multiple nutrient sources were tested resulting in total acid concentration ranging from 20.2 to 34.5 g/L.
163

Decreasing Variation in Cook Color of Ground Beef Patties Varying in Myoglobin and pH Using Acetic Acid and Hydrocolloid Solutions

Aldredge, Teresa Lynn 2009 December 1900 (has links)
The objective was to examine the use of acetic acid (AA) with xanthan gum (XG) or konjac flour (KF) to reduce variation in cooked color of ground beef patties varying in myoglobin and pH. Beef clods were selected from carcasses of young (<24 months, Y) and mature (>48 months, M) animals. Within each age category, high (>6.0, H) and normal pH (5.3-5.7, N) clods were chosen. Ground beef was prepared from each maturity/pH combination and treatments applied at 12% of the meat block: control (mixed only), 0.5% AA, 0.25% XG/0.5% AA, or 0.125% KF/0.5% AA. Dry and moist cooking was performed in a convection oven to internal temperatures: 65.6 degrees C, 71.1 degrees C, and 76.7 degrees C. Patties were held at 76.7 degrees C for up to 240 min in dry and moist environments. Internal (assessed at 0, 120, and 240 min of holding) and external (assessed every 30 min, 0 to 240 min of holding) color evaluations (CIE L*a*b*, visual doneness, and pink scores) were conducted. Three replications were performed. The YN patties had the most done appearance internally and the highest denatured myoglobin percentage. Generally, the YH and MN patties had responses between YN and MH got most variables. The MH patties had the highest internal a* color space values, lowest degree of doneness scores and low percentage of denatured myoglobin. The YN patties responded normally to the different internal temperatures achieved during cooking. The YH, MN, and MH patties had increased doneness to 71.1 degrees C and plateaued between 71.1 degrees C to 76.7 degrees C. Visual degree of doneness decreased during moist holding and this was most evident in dry cook/moist held patties. Patties from MH meat were not affected by the treatments as much as the other meat types. The inclusion of AA, XG/AA, and KF/AA in patties made from YH and MN can effectively reduce visible redness and increase myoglobin denaturation in comparison to the control YN beef patties. These ingredients could be viable options to reduce the variation that pH or myoglobin content imparts on ground beef patty cooked color, but as seen in the MH meat, treatment additions were not effective for overcoming both pH and high myoglobin content.
164

Improvement of Low Quality Meat Utilizing Functional Ingredients

Booren, Betsy Lyn 2008 December 1900 (has links)
Alternative methods to reduce the variation caused by pale, soft, and exudative (PSE) and dark, firm, and dry (DFD) conditions in meat tissues need to be examined. The objective of this dissertation was to determine if functional ingredients, like hydrocolloids and bicarbonates, improved the quality of PSE and DFD meat. This was accomplished by examining the rheological characteristics of meat model systems and products after enhancement with hydrocolloids and bicarbonates ingredient solutions. These results will be used to formulate and manufacture either enhanced beef steaks, beef roasts, or frankfurters to test the efficacy of use to improve the quality of DFD or PSE meat. The flow behavior, steady-shear viscosity, and dynamic testing of hydrocolloid solutions were determined. Torsion Analysis (TA) and Texture Profile Analysis (TPA) were performed on PSE muscle tissue gel samples and frankfurters. Raw and cooked CIE color space values, pH, and sensory evaluation determination were made on meat gel samples, beef steaks, roast beef, and frankfurters. Hydroxypropyl methylcellulose (1.0%HPMC), methylcellulose (1.0%SGMC), and konjac flour (0.125%KF) were found to be Newtonian in behavior. The dynamic moduli of these ingredients were resistant to changes in ionic strength and were tested for viability in a meat model system. Potassium bicarbonate (KHCO) was a viable substitute for sodium bicarbonate. The synergistic effect of combining KHCO with hydrocolloids, salt and sodium phosphate (SP) improved the color, pH, and textural properties of PSE ground pork and frankfurters, but did not effect sensory characteristics. Acetic acid (AA), KF, and xanthan gum (XG) were added to beef steaks and bottom rounds to reduce the meat quality variation caused by high pH and animal age. The addition of AA and hydrocolloid treatments improved the color and pH of high pH muscles and did not appreciable affect shelf-life flavor of cooked roast beef. Solutions of AA, KF and XG were viable enhancement treatments for use in high pH beef bottom rounds to produce a fully cooked roast beef product.
165

Design, Syntheses and Biological Applications of Through-bond Energy Transfer Cassettes and Novel Non-covalently Cell Penetrating Peptides

Han, Junyan 2009 August 1900 (has links)
A xanthene-BODIPY cassette is used as a ratiometric intracellular pH reporter for imaging protein-dye conjugates in living cells. A model was hypothesized to explain the pH-dependent energy transfer efficiencies from the donor to the acceptor based on the electronic chemistry data. Sulfonation conditions were developed for BODIPY dyes to give water-soluble functionalized monosulfonation and disulfonation donors. A water-soluble TBET cassette, which has good photophysical properties, was synthesized using a bissulfonated BODIPY dye as the donor, and their applications for in vitro protein labeling is achieved. Chemoselective cross-coupling reactions were demonstrated for C-S bonds in the BODIPY dye, and similar reactions were applied to make the acceptor of the watersoluble cassette. Chemiluminescent energy transfer cassettes based on fluorescein and Nile Red were synthesized and their spectral properties were studied. Pep-1 (also known as Chariot), R8 (which is not often used as a non-covalent protein carrier), and a new synthesized compound, Azo-R8, was used for the study of non-covalent delivery of four different proteins into mammalian cells. Data from confocal spectroscopy revealed that all three carriers are effective for translocating protein cargos into live cells. At 37 dgrees C, import into endocytic compartments dominates, but at 4 degrees C weak, diffuse fluorescence is observed in the cytosol indicative of a favorable mode of action.
166

Growth of Titanium Oxide Films Using Hexafluorotitanic Acid Solution

Chen, Kuan-Po 18 July 2002 (has links)
In recent years, titanium oxide thin film has been studied extensively for using in optical devices and electronic devices such as waveguide and future ultra-large scale dynamic random access memory (DRAM). Titanium oxide film is very promising candidates for applications with exhibiting higher dielectric constant, high refractive index and high chemical stability. Liquid phase deposition is a novel method to grow oxide layer. It has the advantage of low-temperature deposition, good step coverage, and selective growth. We use this technology to deposition titanium oxide film instead of the conventional methods of growth titanium oxide film, such as sol-gel, sputtering, LPCVD, APCVD, and PECVD. But low deposition rate is one of the drawbacks drawbacks of LPD process. In previous study, deposition rate of titanium oxide films was very slow (6&#x00C5;/min). The mixture of H2TiF6(aq) and H3BO3(aq) was used as the principal solution. In this study, we incorporated HNO3(aq) into the principal solution for enhance the deposition rate. In addition, we study the deposition rate and dielectric constant of titanium oxide films as functions of H2O addition, NH4OH(aq), and Ba(OH)2(aq) concentrations in our principal solution. We examine electrical characteristics and thickness of the titanium films by capacitance-voltage measurement and Spectroscopic Reflectance. The deposition rate of titanium oxide film increases from 6 &#x00C5;/min to 475&#x00C5;/min and the dielectric constant is about 36.1 with adding HNO3 and opportune NH4OH into the principal solution.
167

Survival, attachment and internalization of Salmonella agona and Salmonella gaminara on orange surfaces

Singh, Reema 01 November 2005 (has links)
Salmonella outbreaks associated with orange juices have been reported in the past. Though there have been studies on the internalization of Salmonella into oranges there is inadequate information on the ability of this pathogen to survive on orange surfaces, become internalized, and survive the low pH internal conditions. The objective of this work was to study the survival of Salmonella gaminara and Salmonella agona on oranges obtained from the field and retail outlets and investigate their attachment and internalization potential. These studies showed that oranges obtained from both the field and retail outlets harbored relatively high concentrations of aerobic heterotrophic bacterial populations. There were significant differences in the survival of Salmonella agona and Salmonella gaminara at 4??C, room temperature (25??C) and 37??C. Survival was highest at 37??C and lowest at 4??C for both Salmonella gaminara and Salmonella agona. Salmonella agona and Salmonella gaminara showed significant differences in recovery when the cells were treated with pH 4.0, 7.0 and 9.5 buffers. The internalization studies suggest that a negative temperature differential favors the internalization of Salmonella cells into the fruit. Significant differences in the internalization of Salmonella into field and market oranges were observed with more internalization in the field oranges as compared to the market oranges. These results suggest that to prevent Salmonella contamination of orange juices adequate pre-harvest protection against pathogen contamination and post-harvest cleaning and disinfection strategies need to be employed.
168

Continuous fermentation of food scraps with constant pH control to produce carboxylic acids

Coleman Jr., Stanley Albert 10 October 2008 (has links)
Global energy demands combined with environmental restrictions are fueling a move to alternative energy sources. Biofuels are formed from biomass; the MixAlco process is one such method. In this work, food scraps are explored as a potential feedstock to the MixAlco process. Batch fermentation with various temperatures, buffers, and pH control methods elucidated the behavior of food scraps during fermentation. The pH and reactor configuration were limiting factors when maximizing production. A fermentor was developed and tested with constant pH control. This resulted in elevated concentration (100 g/L) and selectivity (82%) of desired products. The fermentation resulted in elevated concentrations, but low conversion of solids. The undigested material may serve as a nutrient source for fermenting lignocellulosic feedstocks. Combining various nutrient sources with lignocellulose, such as bagasse, resulted in additional production and further conversion. Multiple nutrient sources were tested resulting in total acid concentration ranging from 20.2 to 34.5 g/L.
169

The Characteristic Analysis of DGNNV Virus-Like Particles

Wu, Dong-sheng 16 January 2008 (has links)
Fish nodavirus causes the death of several high economic fish. For studying the package and stability of dragon grouper necrosis virus (DGNNV), wild type virus-like particles (wt-VLPs) and £GN25-VLPs were employed. After experiments of disassembly and assembly, the result showed that DNA of 608 bp was able to be packaged by wt-VLPs. The sedimentation of VLPs was affected by different pH buffers during the process of purification: the VLPs at alkaline conditions behaved faster than those at the acidic. The stability of pure VLPs was pH-independent. The micrographs of the wt-VLPs in alkaline buffers showed that particles were rough and irregular in shapes, some of which were stain-permeable. However, the wt-VLPs in acidic buffers were morphologically indistinguishable from the untreated VLPs. The Western blotting for gradiently purified miture of VLPs and lysozyme revealed that lysozyme was co-precipitated with wt-VLPs.
170

Determinación y evaluación del pH en canales de bovinos de las razas Holstein (Bos taurus) y Nelore (Bos indicus) en Lima - Perú

Mariño Arquiñigo, Gino Oscar January 2003 (has links)
En el estudio se utilizaron 100 bovinos machos, 50 de la raza Holstein (Bos taurus) y 50 de la raza Nelore (Bos indicus), con edades que fluctuaban entre 12 a 24 meses. El objetivo fue determinar la curvas de variación Post mortal del pH para ambas razas durante las primeras 24 horas, las medidas del pH fueron tomados en el músculo Longissimus dorsi, y los datos fueron sometidos a análisis de regresión. El valor del pH se expresó a través de ecuaciones de regresión, por medio del coeficiente de correlación (R2) que fue de tipo cúbica, obteniéndose para la raza holstein (R2 = 0.814) y Nelore (R2 = 0.767). Las medidas del pH se realizaron después de la sangría, en los horarios de 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 24 horas Post mortem. Encontrando los valores estimados de pH para las 24 primeras horas Post mortem para la raza Holstein (Bos taurus) de 6.81, 6.55, 6.33, 6.14, 5.97, 5.84, 5.73, 5.64, 5.58, 5.53, 5.50, 5.48, 5.48, 5.48, 5.49, 5.51, 5.53, 5.55, 5.57, 5.59, 5.60, 5.60, 5.59, 5.57, y para la raza Nelore (Bos indicus) de 6.71, 6.46, 6.24, 6.05, 5.89, 5.75, 5.65, 5.56, 5.50, 5.45, 5.42, 5.40, 5.39, 5.39, 5.40, 5.41, 5.43, 5.44, 5.45, 5.46, 5.46, 5.45, 5.43, 5.40, respectivamente. Los valores de pH en la carne muestran una rápida caída durante las 12 primeras horas y los valores de pH de la raza Holstein (Bos taurus), con respecto a la raza Nelore (Bos indicus) son ligeramente mayores (p < 0.05), aunque siguen similar tendencia a lo largo de las 24 primeras horas Post mortem. / In this study was used 100 cattle male cows, being 50 of Holstein breed (Bos taurus) and 50 Nelore breed (Bos indicus), with ages was between 12 a 24 moths. The objetive of this study was to determine the pH Post mortal variation curves for both breeds during the first 24 hours, the pH measurements was took in the Longissimus dorsi muscle, and the data was to submited regression analysis. The pH value was expressed through the regression ecuations, related to the correlation coefficient (R2) that was a cubic one, the result were (R2 = 0.814) for Holstein and (R2 = 0.767) for Nelore. The pH measurements were perfomed after the slaughter, in the periods of 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 24 hours Post mortem. Find the values to admited of pH for first 24 Post mortem hours the results were for Holstein breed (Bos taurus) of 6.81, 6.55, 6.33, 6.14, 5.97, 5.84, 5.73, 5.64, 5.58, 5.53, 5.50, 5.48, 5.48, 5.48, 5.49, 5.51, 5.53, 5.55, 5.57, 5.59, 5.60, 5.60, 5.59, 5.57, and for Nelore breed (Bos indicus) of 6.71, 6.46, 6.24, 6.05, 5.89, 5.75, 5.65, 5.56, 5.50, 5.45, 5.42, 5.40, 5.39, 5.39, 5.40, 5.41, 5.43, 5.44, 5.45, 5.46, 5.46, 5.45, 5.43, 5.40, respectively. The meat pH values show a fast fall during the first 12 hours and the Holstein (Bos taurus) pH values in contrast to Nelore (Bos indicus) are slightly higher (p < 0.05), even thoughn they follow a similar tendency during the first 24 hours Post mortem.

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