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Baranek, Pascale (Texas A&M University, 1993)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Includes bibliographical references.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1993-THESIS-B225 Files in this item: 1
1993 Thesis B225.pdf (1.964Mb) -
Stewart, Frank Edwin (Texas A&M University, 1964)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1964-THESIS-S849 Files in this item: 1
1964 Thesis S849.pdf (4.289Mb) -
Jeon, Hyung-Joon (August 2009)[more][less]
Abstract: As demand for higher bandwidth I/O grows, the front end design of serial link becomes significant to overcome stringent timing requirements on noisy and bandwidthlimited channels. As a clock reconstructing module in a receiver, the recovered clock quality of Clock and Data Recovery is the main issue of the receiver performance. However, from unknown incoming jitter, it is difficult to optimize loop dynamics to minimize steady-state and dynamic jitter. In this thesis a 10 Gb/s adaptive loop bandwidth clock and data recovery circuit with on-chip loop filter is presented. The proposed system optimizes the loop bandwidth adaptively to minimize jitter so that it leads to an improved jitter tolerance performance. This architecture tunes the loop bandwidth by a factor of eight based on the phase information of incoming data. The resulting architecture performs as good as a maximum fixed loop bandwidth CDR while tracking high speed input jitter and as good as a minimum fixed bandwidth CDR while suppressing wide bandwidth steady-state jitter. By employing a mixed mode predictor, high updating rate loop bandwidth adaptation is achieved with low power consumption. Another relevant feature is that it integrates a typically large off-chip filter using a capacitance multiplication technique that employs dual charge pumps. The functionality of the proposed architecture has been verified through schematic and behavioral model simulations. In the simulation, the performance of jitter tolerance is confirmed that the proposed solution provides improved results and robustness to the variation of jitter profile. Its applicability to industrial standards is also verified by the jitter tolerance passing SONET OC-192 successfully.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7183 Files in this item: 1
JEON-THESIS.pdf (1.808Mb) -
Edgar, Leslie Dawn (December 2007)[more][less]
Abstract: The field of agricultural education relies on multiple research journals to disseminate findings. This study focused on a 10-year content analysis of research published in premier journals in agricultural education. The study ascertained primary research themes, types of research conducted, prolifically published authors, frequently cited authors, and frequently cited referenced works, and discussed how the formation and usage of research in agricultural education has changed from 1997 to 2006. The study sought assistance from agricultural educators to narrow the focus of the study and to ensure study content validity. A conceptual model, based on a thorough review of literature and a focus on the peer discipline areas of agricultural education, guided the study. The study utilized a field study and employed descriptive statistics. Premier agricultural education (AGED) journals were identified: the Journal of Agricultural Education (93%); Journal of International Agricultural and Extension Education (67%); Journal of Extension (63%); North American Colleges and Teachers of Agriculture Journal (48%); Journal of Applied Communications (41%); and Journal of Leadership Education (41%). The study identified primary and secondary research themes, prolific authorship, research methods and types, and frequently cited authors and referenced works in each of the identified premier AGED journals. The research used compiled data, from each of the research journals, to analyze the frequencies and gaps identified in the National Research Agenda [NRA]: Agricultural Education and Communication 2007-2010 (2007). Agricultural education in domestic and international settings: Extension and outreach was the research priority area noted as the most frequently identified in past research and no gaps were identified in the NRA. To continue to strengthen the agricultural education discipline, research from this study should be used to adjust research priority areas in the NRA and on the regional and state levels.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2413 Files in this item: 1
EDGAR-DISSERTATION.pdf (749.7Kb) -
Rue, Clayton Matthew (Texas A&M University, 1981)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Bibliography: leaves 30-31.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1981-THESIS-R918 Files in this item: 1
1981 Thesis R918.pdf (1.902Mb) -
York, Melissa Dawn (August 2007)[more][less]
Abstract: Renal cell carcinoma (RCC) accounts for 85% of kidney cancer incidence in the US. Since 1950 there has been a 126% increase in kidney cancer incidence in the US. Thirty percent of new patients present with a localized easily treatable carcinoma while 30% of patients present with a high-grade metastatic carcinoma. Five-year survival rates for metastatic RCC is 6-12 months (Lipworth et al, 2006). Current disease treatment options for metastasis include chemotherapy and radiation (8% response rate), immunotherapy (15-30% response rate) and newly developed angiogenesis inhibitors which are in phase III trials (Staehler et el, 2005). In RCC cells, it has been shown that PPARγ agonists inhibit cell proliferation, induce apoptosis, and induce anti-angiogenic effects in vitro. Unlike most tumor types, PPARγ is downregulated in tissue samples from 47 RCC patients. However, in cell culture studies PPARγ expression does not correlate with growth inhibitory or apoptotic effects of PPARγ agonists in renal cell lines indicating that PPARγ independent responses may play a large role in actions associated with the PPARγ agonists (Yuan et al, 2006). 1,1-Bis(3'-indolyl)-1-(p-substitutedphenyl)methanes containing p-trifluoromethyl, p-t-butyl and p-phenyl substituents activate peroxisome proliferator-activated receptor (PPAR) and inhibit growth of ACHN and 786-0 renal cell carcinoma cell lines. PPAR is overexpressed in ACHN cells and barely detectable in 786-0 cells, and treatment with the t-butyl analog (DIM-C-pPhtBu) induces cell cyle inhibition. DIM-C-pPhtBu also induced several common PPAR-independent proapoptotic responses in ACHN and 786-0 cells, including increased expression of nonsteroidal antiimflammatory drug-activated gene-1 (NAG-1) and endoplasmic reticulum stress which activates death receptor 5 and the extrinsic pathway of apoptosis. In addition, DIM-C-pPhtbu (40 mg/kg/d) also inhibited tumor growth in an orthotopic mouse model for renal carcinogenesis, and this was accompanied by induction of apoptosis in renal tumors treated with DIM-C-pPhtBu but not in tumors treated with the corn oil vehicle (control). Thus, DIM-C-pPhtBu and related compounds represent a novel class of mechanism-based drugs that have potential for treatment of renal adenocarcinoma for which there are currently limited options for successful chemotherapy.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1968 Files in this item: 1
YORK-THESIS.pdf (33.97Mb) -
11th Grade Students' English Reading Motivation, Language Problems and Reading Achievement in TaiwanSu, Jung-Hsuan (May 2012)[more][less]
Abstract: Motivation has been viewed as a very influential factor to successful reading for English as foreign language learners. Learners can be motivated to read English by extrinsic or intrinsic motivation, and the motivational orientations could also influence their reading achievement. However, language problems that EFL learners encounter while reading can affect their willingness to read as well as their reading achievement. The purpose of this study was to investigate Taiwanese EFL students’ English reading motivation and its relationship with perceived language problems and reading achievement. 302 11th grade students from an urban district in southern Taiwan participated in the study. Measures included an English reading comprehension test, an English reading motivation questionnaire, and a questionnaire regarding language problems in reading English. A factor analysis was used to determine the motivational orientations. Multiple regression and correlation analysis were performed to examine the relationship among reading motivation, language problems, and reading achievement. The results showed that: 1) Taiwanese senior high school students were largely motivated to read English by extrinsic motivation, specifically the importance and instrumental utility of reading English and the drive for recognition and competition, although they could also be motivated by intrinsic motivation to read English for knowledge and social purposes. Moreover, extrinsic motivation to read for compliance was significantly associated with their English reading scores. 2) While reading English, unknown idiomatic expressions and vocabulary were frequently reported language problems that influenced students’ willingness to read. Nevertheless, lack of grammar knowledge was generally not considered a big language problem to most of the students while reading. 3) Language problems in reading English and reading motivation were correlated, and motivation to read for compliance, grammar knowledge, and overall reading comprehension were significant predictors of students’ English reading scores. This study highlights the influential role of extrinsic motivation to EFL students in English reading and the importance of knowledge of vocabulary and idiomatic expressions in order to help understand the meaning of English texts. It provides implications for English teachers in designing appropriate curriculum that suits students’ needs and interests, and also suggestions for choosing proper reading materials.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11187 Files in this item: 1
SU-DISSERTATION.pdf (1.988Mb) -
Jung, Jae Won (Texas A&M University, May 2003)[more][less]
Abstract: A beta-emitting glass seed was proposed for the brachytherapy treatment of prostate cancer. Criteria for seed design were derived and several beta-emitting nuclides were examined for suitability. 142Pr was selected as the isotope of choice. Seeds 0.08 cm in diameter and 0.9 cm long were manufactured for testing. The seeds were activated in the Texas A&M University research reactor. The activity produced was as expected when considering the meta-stable state and epi-thermal neutron flux. The MCNP5 Monte Carlo code was used to calculate the quantitative dosimetric parameters suggested in the American Association of Physicists in Medicine (AAPM) TG-43/60. The Monte Carlo calculation results were compared with those from a dose point kernel code. The dose profiles agree well with each other. The gamma dose of 142Pr was evaluated. The gamma dose is 0.3 Gy at 1.0 cm with initial activity of 5.95 mCi and is insignificant to other organs. Measurements were performed to assess the 2-dimensional axial dose distributions using Gafchromic radiochromic film. The radiochromic film was calibrated using an X-ray machine calibrated against a National Institute of Standards and Technology (NIST) traceable ion chamber. A calibration curve was derived using a least squares fit of a second order polynomial. The measured dose distribution agrees well with results from the Monte Carlo simulation. The dose was 130.8 Gy at 6 mm from the seed center with initial activity of 5.95 mCi. AAPM TG-43/60 parameters were determined. The reference dose rate for 2 mm and 6 mm were 0.67 and 0.02 cGy/s/mCi, respectively. The geometry function, radial dose function and anisotropy function were generated.
URI: http://hdl.handle.net/1969.1/5738 Files in this item: 1
etd-tamu-2007A-NUEN-Jung.pdf (2.847Mb) -
McElhany, Katherine (December 2010)[more][less]
Abstract: Environmental microbiology has traditionally been performed using culture-based methods. However, in the last few decades, the emergence of molecular methods has changed the field considerably. The latest development in this area has been the introduction of next-generation sequencing, including pyrosequencing. These technologies allow the massively parallel sequencing of millions of DNA strands and represent a major development in sequencing technologies. The purpose of this study was to use both pyrosequencing and traditional culture-based techniques to investigate the diversity and dynamics of bacterial populations within milk and untreated sewage sludge samples. Pasteurized and raw milk samples were collected from grocery stores and dairies within Texas. Milk samples were analyzed by plating, pyrosequencing, and an assay for the presence of cell-cell signaling molecules. Samples were processed, stored, and then evaluated again for spoilage microflora. The results of this study showed that raw milk had a considerably higher bacterial load, more diversity between samples, and a significantly higher concentration of pathogens than pasteurized milk. Additionally, this study provided evidence for varying spoilage microflora between raw and pasteurized milk, as well as evidence for the production of cell-cell signaling molecules by bacterial organisms involved in milk spoilage. Four samplings of untreated sewage sludge were collected from wastewater treatment plants in seven different municipalities across the United States. Samples were subjected to quantification of selected bacterial organisms by culture and a pyrosequencing analysis was performed on extracted community DNA. The results of this study showed that untreated sewage sludge is inhabited by a huge diversity of microorganisms and that certain municipalities may have distinct bacterial populations that are conserved over time. Additionally, this study provided some evidence for seasonal differences in several of the major bacterial phyla. Lastly, this study emphasized the challenges of comparing results obtained by culture and pyrosequencing. In conclusion, this study showed that both milk and sewage are highly diverse, dynamic environments that can contain organisms of public health concern. The use of both culture-based methods and pyrosequencing in this study proved a complementary approach, providing a more comprehensive picture of both microbial environments.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8933 Files in this item: 1
MCELHANY-THESIS.pdf (3.172Mb) -
Hoskins, Sara Grace (Texas A&M University, December 2003)[more][less]
Abstract: Within the collections of the Museu de Angra do Heroismo (Terceira Island, Azores, Portugal) are nine cast bronze guns from the 16th century. Most were raised from the seafloor between the 1960s and 1990s, but this study comprises the first in-depth research into their design and manufacture. The importance of this kind of study lies in the fact that ordnance is commonly found on shipwrecks of this time. A greater knowledge of guns will help provide information about the ships from which they came. Careful documentation and study of the Museu de Angra cannon will add greatly to their value as museum exhibits, by allowing museum patrons to better understand where the guns came from, how they were cast, and why they were important. This documentation adds to our knowledge of Western European gunfounding technology during the sixteenth century, as four different countries commissioned the guns: Portugal, Spain, France, and England. With detailed documentation and publication, the Museu de Angra bronze guns can be added to the bibliography of ordnance of this period, which will aid future researchers who encounter similar pieces. The Museu de Angra bronze guns, as symbols of the military and naval power of the countries that commissioned them, were sent aboard ships, into the field, and mounted on fortress walls. Bronze guns of this time period are particularly important, as bronze was an expensive commodity, and the demand for ordnance was increasing rapidly. Countries developed more effective ways to make use of iron for the founding of guns, and the use of bronze became more symbolic of wealth. The information that each gun contains includes both the cutting-edge military technology of the time and the artistic statement of the founder. Some of the finest metalwork of the period was displayed in cast bronze guns, and due to the founding techniques, no two are the same, making each an important piece of history.
URI: http://hdl.handle.net/1969.1/556 Files in this item: 1
etd-tamu-2003C-ANTH-Hoskins-1.pdf (10.11Mb) -
Gunay, Zeki Sezgin (Texas A&M University, 1997)[more][less]
Abstract: The objective of this thesis is to develop a pipelined analog-to-digital converter which operates under a single supply voltage of 1.8V and is capable of resolving 10 bits at a rate of IOMS/sec. Although the overall architecture of the developed pipelined converter is a general one at the system level, a family of new low-voltage building blocks is proposed. The amplifiers and comparators which are designed to perform interstage processing have high gain-bandwidth products and they are capable of operating at supply levels of less than the initial specification of 1.8V. To test the concepts used to design important blocks such as amplifiers and comparators, a chip prototype amplifier is fabricated in a 1.2nm standard CMOS process and is tested to be functional. The entire converter system is designed using a 0.5/,nm standard CMOS process and its layout is completed. A patent application is filed for the offset cancelation utilizing capacitive levelshift devices for single-ended amplifiers.
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Includes bibliographical references.
Issued also on microfiche from Lange Micrographics.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1997-THESIS-G863 Files in this item: 1
1997 Thesis G863.pdf (2.901Mb) -
Lee, Kye-Shin (Texas A&M University, 2002)[more][less]
Abstract: In order to satisfy today's most important requirements of the A/D and D/A converters that are low voltage and high speed operation, a low voltage and high speed circuit solutions for [] modulators are strongly demanding. However, simply reducing the supply voltage and increasing the clock frequency of the [] modulator will introduce severe constraints to the design. In this thesis, a 1.8V 2-2 cascade [] modulator with 1MHz signal bandwidth is realized by employing a modified [] modulator structure which can limit the output swing of the integrator within half the reference voltage. As a result, the supply voltage can be easily reduced without any degradation of the modulator performance. Moreover, the slew rate and bandwidth requirements of the OpAmp are much more alleviated. Also, using only single bit quantizers in each stage, linearity and matching problems are not critical. Circuit level simulation results show a peak SNR of 77.3dB and a peak SNDR of 72.1dB which corresponds to a nearly 13 bit resolution.
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Includes bibliographical references (leaves 79-82).
Issued also on microfiche from Lange Micrographics.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2002-THESIS-L455 Files in this item: 1
2002 Thesis L455.pdf (2.366Mb) -
Johnson, Gloria Childs (Texas A&M University, 1971)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1971-THESIS-J67 Files in this item: 1
1971 Thesis J67.pdf (5.642Mb) -
Furrh, Samuel Roger (Texas A&M University, 1970)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1970-THESIS-F991 Files in this item: 1
1970 Thesis F991.pdf (5.822Mb) -
Arneson, Lynn A (Texas A&M University, 1988)[more][less]
Abstract: Not available
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Bibliography: leaves 79-81.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1988-THESIS-A748N Files in this item: 1
1988 Thesis A748N.pdf (2.431Mb) -
Osborn, Lacye Ann (Texas A&M University, 1994)[more][less]
Abstract: The objectives of this study were to develop a nutrition scoring system which would combine the nutritional information on the new label into a single number, to identify strengths and weaknesses of the new nutritional labels according to nutrition and food industry professionals and to determine if any differences exist between professionals' perception of the nutritional label. A scoring system was designed using the components on the new nutritional label. Labels from main dish products were used for scoring. Each component was given points of 0, 25, 50, 75 or 100 according to the amount present. A score was assigned based on an average of the points. When incorporated with the existing label, the scoring system could be very useful to consumers while still providing specific information for individuals. By making the label easier to understand, it would add to the consumer's willingness to use the label. A questionnaire to assess attitudes toward each component on the new nutritional label was sent to members of the American Dietetic Association (ADA, n--1220)andthelnstituteofFoodTechnologists(IFT,n--441). Atotalof464 professionals (28%) responded of which 79% and 22% were ADA and IFT members, respectively. Responses varied with subject age, position, job function and area of practice or responsibility. With the exception of protein, ADA respondents considered each component of the label to be more important than did I]FT respondents. Both groups ranked kilocalories (kcal), total fat, and sodium to be more important components and vitamin A and C and sugars less important. ADA respondents indicated that percentage kcal from fat and other vitamins and minerals should be added to the label. IFT respondents were concerned with the process and the costs required to modify the labels. In conclusion, the nutritional components on the new label were acceptable to this sample of the population. The observation that differences of opinions within the groups of professionals were not as widespread as expected is important. The less variation seen within the parties involved in label policy, the easier it should be to produce nutrition messages which consumers will understand.
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Includes bibliographical references.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-O813 Files in this item: 1
1994 Thesis O813.pdf (3.299Mb) -
Grimes, Shepherd Russell (Texas A&M University, 1996)[more][less]
Abstract: On November 8, 1994 the Florida electorate voted 2,876,091 to 1,135,110 in favor of proposed amendment #3 to the state constitution. The amendment effectively reallocated the state's nearshore fisheries to predominantly recreational "hook and line" anglers through a ban on the use of certain net gear. The amendment was initiated via a petition drive supported by a coalition of recreational fishing and conservation groups. These interest groups have continued to play an increasingly important role in the management of Florida's marine fisheries resources. This thesis presents a case study of the issues and events leading to the electoral approval of Article X, Section 16 of the Florida Constitution. An in-depth look at the case is presented, highlighting critical issues and occurrences. Also, theoretical explanations for case findings are presented. The vigor of related interest groups was the key to the initiation and success of the referendum. For years, well-organized groups representing the commercial industry maintained a considerable presence and influence in state government. Focusing much of their efforts on the Governor and Cabinet, and pursuing rule challenges, these groups prevented the implementation of numerous regulations supported by recreational interests. After limited success through institutional channels, recreational interests formed a coalition and initiated a petition drive that succeeded in getting the proposed amendment on the ballot. The established institutions responsible for marine fisheries management in Florida failed to appreciate the strength of organized recreational fishing interests within the state. Although its inability to sufficiently address the issue was partially attributable to the institutional hierarchy, the Florida Marine Fisheries Commission must better appreciate the role of such interest groups.
Description: Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.
Includes bibliographical references: p. 101-109.
Issued also on microfiche from Lange Micrographics.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-1996-THESIS-G76 Files in this item: 1
1996 Thesis G76.pdf (3.374Mb) -
Stefanou, Nikolaos (Texas A&M University, May 2006)[more][less]
Abstract: Hard disk drive applications require a high Spurious Free Dynamic Range (SFDR), 6-bit Analog-to-Digital Converter (ADC) at conversion rates of 1GHz and beyond. This work proposes a robust, fault-tolerant scheme to achieve high SFDR in an av- eraging flash A/D converter using comparator chopping. Chopping of comparators in a flash A/D converter was never previously implemented due to lack of feasibility in implementing multiple, uncorrelated, high speed random number generators. This work proposes a novel array of uncorrelated truly binary random number generators working at 1GHz to chop all comparators. Chopping randomizes the residual offset left after averaging, further pushing the dynamic range of the converter. This enables higher accuracy and lower bit-error rate for high speed disk-drive read channels. Power consumption and area are reduced because of the relaxed design requirements for the same linearity. The technique has been verified in Matlab simulations for a 6-bit 1Gsamples/s flash ADC under case of process gradients with non-zero mean offsets as high as 60mV and potentially serious spot offset errors as high as 1V for a 2V peak to peak input signal. The proposed technique exhibits an improvement of over 15dB compared to pure averaging flash converters for all cases. The circuit-level simulation results, for a 1V peak to peak input signal, demon- strate superior performance. The reported ADC was fabricated in TSMC 0.18 ??mCMOS process. It occupies 8.79mm2 and consumes about 400mW from 1.8V power supply at 1GHz. The targeted SFDR performance for the fabricated chip is at least 45dB for a 256MHz input sine wave, sampled at 1GHz, about 10dB improvement on the 6-bit flash ADCs in the literature.
URI: http://hdl.handle.net/1969.1/2469 Files in this item: 1
etd-tamu-2005A-ENGR-Stefanou.pdf (1.120Mb) -
Bernhardt, Michelle Lee (December 2009)[more][less]
Abstract: The United States contains an estimated 100,000 miles (160000 km) of levees in which erosion related issues are the top priorities. Proper documentation of overtopping induced erosion is a complicated issue involving the collection and analysis of timesensitive field data and personal observations. This thesis is a study of the performance of the Midwest Levee system during the 2008 flooding events. The goal of the Midwest Levee investigation was to gather and analyze perishable data in an effort to provide a comprehensive overview at each breach location. To predict how a site will perform during a particular flood event, there are three main inputs: the flood conditions, the site conditions, and the soil properties. Site geometry and imperfections can greatly affect the performance of a levee system. Any low spots or potential seepage paths can concentrate the flow and be detrimental to the levee. The vegetative cover is the single most important condition at a site. As seen in the Brevator case, vegetative armor can prevent failure of a levee comprised of less resistant soils subjected to long periods of overtopping. Recommended grasses include: Switchgrass, Smooth Brome, Reed Canarygrass, and Tall Fescue. It is also recommended that grasses are kept at least 0.5 m tall during the flood season and to limit the presence of trees to 10 m beyond the levee toe. The erosion resistance of the materials comprising the levee is also important. From the correlations in this study, it was determined that erodibility is influenced by grain size, relative compaction, clay content, and activity. Devices like the Torvane and Pocket Erodometer can also be used to get a quick field estimate of erosion. While these correlations and field devices give insight into an erodibility value, they are no substitute for site specific analysis with laboratory equipment such as the Erosion Function Apparatus. Soil behavior is highly nonlinear and the entire erosion function is needed to get an accurate measure of the erodibility of a soil. By combining these properties in an erosion matrix, a prediction of whether a site will withstand a given flood event can be made.
URI: http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7423 Files in this item: 1
BERNHARDT-THESIS.pdf (96.68Mb) -
Ayala, Julio Enqrique, II (Texas A&M University, December 2005)[more][less]
Abstract: Recently, there is a growing interest in applying electronic circuit design for biomedical applications, especially in the area of nuclear magnetic resonance (NMR). NMR has been used for many years as a spectroscopy technique for analytical chem- istry. Previous studies have demonstrated the design and fabrication of planar spiral inductors (microcoils) that serve as detectors for nuclear magnetic resonance mi- crospectroscopy. The goal of this research was to analyze, design, and test a prototype integrated sensor, which consisted of a similar microcoil detector with analog components to form a multiple-channel front-end for a magnetic resonance imaging (MRI) system to perform microspectroscopy. The research has succeeded in producing good function- ality for a multiple-channel sensor. The sensor met expectations compared to similar one-channel systems through experiments in channel separation and good signal-to- noise ratios.
URI: http://hdl.handle.net/1969.1/4729 Files in this item: 1
etd-tamu-2005C-ELEN-Ayala.pdf (1.933Mb)
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