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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.
301

A Study on the Mathematical Model of Optical Fiber End Profile Using Envelope Theory

Liao, Wei-chen 12 August 2008 (has links)
Using the envelope theory, the mathematical model of the end face profile and the working tool path of a special optical fiber polishing machine is deve- loped in this study. During the polishing process, the polisher is controlled by three parameters including the fiber rotational angle, the height H and the angle between the fiber and polisher. The contact points between the optical fiber and the polishing plate will determine the profile of the fiber end face. The 3-D end face with double-variable curvatures can be fabricated by properly controlling these three parameters. Since the grinding (polishing) material removal rate is related to machining time and normal contact force, the grinding (polishing) tool path and parameters are needed some modification in order to get the precise end profiles. Example of fiber end faces of 2-D elliptical face and 3-D ellipsoid are given to check the developed mathematical model in this study by computer solid modeling.
302

A MMC Controller for Wearable Data Logging and Front-end Amplifier

Huang, Yan-ru 13 August 2009 (has links)
There are many kinds of commercial memory cards on the market. Due to great improvements in modern technology, they have great amounts of capacity, low power consumption, and are easily available. Therefore a data logging system using a commercial memory card is a convenient and economic procedure. This thesis introduces a wearable data logging system for physiological recording. A front-end amplifier, analog to digital converter, and a memory card controller compose the basis of this system. The front-end amplifier uses a switched-capacitor structure, so the output waveform is discrete in regard to the time domain. This brings an advantage in saving power for not keeping charging the load capacitance. Lateral bipolar transistors fabricated in a CMOS process are used as input devices. A conventional ADC is used to convert the amplified signal into digital data. Finally MultiMediaCard is chosen as a large storage space. This thesis contributes the analysis, design and measurement of the amplifier front-end. In addition, the design and implementation of a controller circuit for sequential data storage into the MultiMediaCard memory is described. Special attention was paid to achieving a small area, low-complexity and low-power implementation suitable for integration. Measured results obtained from a preliminary FPGA implementation are reported and the functionality of a complete logger circuit is demonstrated with measured results.
303

Essays on closed-end funds : discounts, noise traders, and arbitrage /

Hughen, John Christopher, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 84-88). Also available on the Internet.
304

Understanding and supporting end-user debugging strategies /

Grigoreanu, Valentina. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 223-236). Also available on the World Wide Web.
305

Essays on closed-end funds discounts, noise traders, and arbitrage /

Hughen, John Christopher, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 84-88). Also available on the Internet.
306

Towards Good Palliation for Children with Cancer : Recognizing the Family and the Value of Communication

Jalmsell, Li January 2015 (has links)
Pediatric cancer imposes a threat on the child’s life and approximately every fifth child diagnosed with cancer will die due to his or her disease. The overall aim of this thesis was to explore palliative care of children with cancer and bereaved family members. The thesis includes data collected retrospectively from medical records, a nationwide questionnaire directed to bereaved parents, a nationwide questionnaire for bereaved siblings and individual interviews with children in cancer care. Most children dying from cancer were recognized as being beyond cure at time of death; for some this recognition occurred close to death, leaving little time for potential personal preferences (Paper I). Bereaved parents and siblings noticed extensive suffering in the child close to death (Paper II, VI), with physical fatigue being the most commonly reported symptom irrespectively of age and diagnosis of the child (Paper II). Bereaved parents’ psychological well-being appears to be closely related to experiencing suffering in the dying child (Paper III) but also to high-intensity treatment (with bone marrow transplant as the example) of a child that still dies from his or her disease (Paper IV). Bereaved siblings experience a lack in information at the end of their brother’s or sister’s life and report feeling poorly prepared for the loss. An increased risk of anxiety was seen in siblings whom nobody talked to about what to expect at the time of death of their brother or sister (Paper VI). When caring for children with cancer it is vital to take the individual child’s awareness and preferences regarding information into consideration. Bereaved parents who have communicated with their child about death expressed that this often occurred at the child’s own initiative (Paper V) and simple means such as fairy tales could be used to facilitate communication. Ill children themselves expressed in interviews wanting honest, but still hopeful information regarding bad news (Paper VII). The results of this thesis stress the importance of striving to achieve good communication and keeping a family perspective throughout care of children with cancer.
307

Combined effects of global warming and a shutdown of the Atlantic meridional overturning circulation on West African and European climate

Brown, Meredith Guenevere Longshore 20 July 2012 (has links)
The Atlantic meridional overturning circulation has a vast potential for abrupt climate change due to its large heat transport through the ocean and its nonlinear dynamics. Because of these unique properties, this paper investigates how the climate of West Africa and Europe will respond to a shutdown of the Atlantic meridional overturning circulation at the end of the 21st century. Here we use a regional climate model with 90-km grid spacing is forced by an idealized sea-surface temperature anomaly, based upon coupled atmosphere/ocean global model water hosing experiments, with a business-as-usual global warming scenario to discover how West African and European climate will change. In both the boreal spring and summer, cooling in the eastern Atlantic is associated with a strong intensification and eastward extension of the North Atlantic subtropical high over Europe throughout the depth of the atmosphere, a strengthening of the heat low over West Africa at low levels, and a weakening of the Saharan High in the upper atmosphere. Rainfall rates also decrease markedly throughout most of West Africa and Europe: in spring, rainfall rates decrease by 50-80% over Sahelian Africa, in summer rainfall over Europe decreases by up to 90%, while precipitation over West Africa is reduced by 40%. / text
308

Spironolactone to treat hypertension in end-stage renal disease : analysis of effectiveness and safety

Smith, Amber Lanae 30 January 2014 (has links)
Purpose: Cardiovascular events and complications are the major causes of death in patients with end-stage renal disease (ESRD)¹⁻³. Antihypertensive agents that block the renin-angiotensin-aldosterone system (RAAS) are considered first-line therapy in patients with ESRD as these patients have a propensity for RAAS overactivation⁴⁻⁷. Studies show that aldosterone receptor blockade reduces BP in patients with chronic kidney disease (CKD) and helps prevent negative outcomes from continued renal cellular damage⁸⁻¹⁰. Spironolactone, an aldosterone antagonist, has the potential to provoke hyperkalemia. Consequently, current guidelines do not recommend spironolactone to manage hypertension in ESRD because of this risk⁶⁻⁷. Our primary objectives were to determine the change in BP and serum potassium levels following spironolactone use. Methods: This study was a retrospective, pre-post cohort study in ESRD patients with difficult-to-control BP receiving HD. Patients prescribed spironolactone (25 mg to 50 mg) between January 2009 and January 2013 were identified using an e-prescribing record from three HD clinics in San Antonio, TX. Patients were included if they were prescribed spironolactone as 'add-on' therapy to control BP for at least 8 weeks. Results: Seventy patients were evaluated and the majority of them were overweight, diabetic, Hispanic females with a mean 65 years of age. Mean SBP and DBP decreased from baseline to week 8 [-20.74 mmHg (p < 0.0001) and -9.7 mmHg (p < 0.0426), respectively]. Mean serum potassium levels increased by an average of 0.18 mEq/L (4.5 mEq/L to 4.68 mEq/L, p = 0.09). Data analysis revealed that only 9 of 70 patients had a serum potassium level > 5.5 mEq/L at week 8. There were no adverse cardiac events reported as a result of these potassium concentrations. A two-fold decrease in SBP was seen in patients with a body mass index (BMI) > 25 kg/m² compared to patients with a BMI of ≤ 25 kg/m². At the end of the study, 23 patients (33%) achieved the goal BP for healthy adults of < 140/90 mmHg. Conclusion: These findings demonstrated that using spironolactone use in ESRD patients receiving HD can be effective and safe. / text
309

Case study analysis in support of front end planning on capital projects

Irons, Kyle Taylor 08 July 2015 (has links)
Many research investigations have indicated that projects have a higher chance of success when thorough front end planning is performed. Previous research efforts have sought to determine a statistical link between front end planning and the performance metrics for both building and industrial projects. The author of this thesis intends to supplement prior research with case study analysis that provides situational insight that supports business decision making of business managers and project representatives. The research conducted in this study was performed in conjunction with CII Research Team 213, Support for Pre-Project Planning. The data for this thesis was gathered through a series of questionnaires and interviews with project representatives from 17 projects totaling $1.5 billion. Case studies were written by the author, reviewed by supervising professor and project representatives for accuracy and anonymity. The lessons learned from the case studies were distilled and evaluated to uncover correlations between front end planning issues and project success. A matrix of issues was created, and along with pattern-matching techniques, project data were sorted. The conclusions were drawn using expert knowledge of the author, supervising professor and research team. The case study analyses identified several planning related issues that affect project success, including: defined front end planning process, adequate scope definition, existing conditions definition, correct contracting strategy, alignment, teambuilding, participation of owner and contractors in the front end planning process, leadership, experience, and labor availability and skill. Anecdotal evidence is provided to support the proper implementation of these issues. / text
310

ATPase dependent and independent roles of Brahma in transcription and pre-mRNA processing

Yu, Simei January 2015 (has links)
SWI/SNF is a chromatin-remodeling complex and Brahma (BRM) is the ATPase subunit of SWI/SNF. BRM regulates transcription by remodeling the nucleosomes at promoter regions. BRM is also associated with RNA and affects pre-mRNA processing together with other SWI/SNF subunits. In this thesis, I will discuss the roles of BRM in both transcription and pre-mRNA processing. In Paper I, we showed that BRM, as well as other SWI/SNF subunits SNR1 and MOR, affects the alternative processing of a subset of pre-mRNAs, as shown by microarray analysis. This observation was validated by RNAi experiments both in Drosophila S2 cells and in vivo. In Paper II, we characterized the trans-splicing of transcripts derived from the mod(mdg4) gene. RNA interference (RNAi) and overexpression experiments revealed that BRM regulates the trans-splicing of mod(mdg4)-RX in an ATPase independent manner. In Paper III, we analyzed the expression of two BRM-target genes identified in Paper I, CG44250 and CG44251. RNAi and overexpression experiments showed that the expression levels of these two genes were affected by BRM in a manner that is independent of its ATPase activity. Transcriptome analysis further proved that BRM affects gene expression both in ATPase dependent and independent manners. In Paper IV, we showed that BRM is present at the 3’-end of two analyzed genes, CG5174 and CG2051. BRM facilitates the recruitment of the cleavage and polyadenylation machinery to the cleavage sites through protein-protein interactions that do not require the ATPase activity of BRM. Morevoer, BRM promotes the cleavage of the CG5174 and CG2051 pre-mRNAs. To sum up, SWI/SNF plays important roles not only in transcription but also in pre-mRNA processing. To regulate transcription, BRM can either act as an ATPase-dependent chromatin remodeler or in a manner that does not involve ATPase activity. Additionally, BRM interacts with RNA-binding proteins to regulate the processing of a subset of pre-mRNAs, and this function of BRM is independent of its chromatin remodeling activity. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>

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