Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 112-113).

abstract: Biophysical techniques have been increasingly applied toward answering biological questions with more precision. Here, three different biological systems were studied with the goal of understanding their dynamic differences, either conformational dynamics within the system or oligomerization dynamics between monomers. With Cy3 on the 5' end of DNA, the effects of changing the terminal base pair were explored using temperature-dependent quantum yields. It was discovered, in combination with simulations, that a terminal thymine base has the weakest stacking interactions with the Cy3 dye compared to the other three bases. With ME1 heterodimers, the goal was to see if engineering a salt bridge at the dimerization interface could allow for control over dimerization in a pH-dependent manner. This was performed experimentally by measuring FRET between monomers containing either a Dap or an Asp mutation and comparing FRET efficiency at different pHs. It was demonstrated that the heterodimeric salt bridge would only form in a pH range near neutrality. Finally, with DNA processivity clamps, one aim was to compare the equilibrium dissociation constants, kinetic rate constants, and lifetimes of the closed rings for beta clamp and PCNA. This was done using a variety of biophysical techniques but with three as the main focus: fluorescence correlation spectroscopy, single-molecule experiments, and time-correlated single photon counting measurements. The stability of beta clamp was found to be three orders of magnitude higher when measuring solution stability but only one order of magnitude higher when measuring intrinsic stability, which is a result of salt bridge interactions in the interface of beta clamp. Ongoing work built upon the findings from this project by attempting to disrupt interface stability of different beta clamp mutants by adding salt or changing the pH of the solution. Lingering questions about the dynamics of different areas of the clamps has led to another project for which we have developed a control to demystify some unexpected similarities between beta clamp mutants. With that project, we show that single-labeled and double-labeled samples have similar autocorrelation decays in florescence correlation spectroscopy, allowing us to rule out the dyes themselves as causing fluctuations in the 10-100 microsecond timescale. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2015

This thesis focuses on identifying hard material pairs with low roughness, high coefficient of static friction, high wear resistance and high modulus of elasticity, suitable for sliding in dry friction conditions under a normal load. A wide range of materials including various steels, various coatings on tool steels deposited by various deposition techniques and different ceramics were examined and considered for tribological testing. Procedures and sequences were developed for conducting tribology tests on the material pairs. High endurance - low cycle tests were conducted and based on the performance of material pairs with respect to friction, wear and surface roughness a small set of material pairs and coatings was selected for further testing. High endurance - high cycle tests were performed on an additional seventeen pairs of material pairs selected for long term sliding. Material pairs were selected for low endurance tests based on high corrosion resistance along with all the above specified design parameters. Low endurance tests were conducted to identify material pairs sliding for a short distance in humid environments. Results are tabulated and pictures of the material pairs after wear tests are presented. It was found that four material pairs for high endurance applications and two pairs for the low endurance applications performed very well in regard of design specifications. These material pairs find a major application in friction clamps of an Inchworm motor resulting in enhancement of force output of the motor.

Title from PDF of title page. / Document formatted into pages; contains 78 pages. / Thesis (M.S.M.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This thesis focuses on identifying hard material pairs with low roughness, high coefficient of static friction, high wear resistance and high modulus of elasticity, suitable for sliding in dry friction conditions under a normal load. A wide range of materials including various steels, various coatings on tool steels deposited by various deposition techniques and different ceramics were examined and considered for tribological testing. Procedures and sequences were developed for conducting tribology tests on the material pairs. High endurance - low cycle tests were conducted and based on the performance of material pairs with respect to friction, wear and surface roughness a small set of material pairs and coatings was selected for further testing. High endurance - high cycle tests were performed on an additional seventeen pairs of material pairs selected for long term sliding. / ABSTRACT: Material pairs were selected for low endurance tests based on high corrosion resistance along with all the above specified design parameters. Low endurance tests were conducted to identify material pairs sliding for a short distance in humid environments. Results are tabulated and pictures of the material pairs after wear tests are presented. It was found that four material pairs for high endurance applications and two pairs for the low endurance applications performed very well in regard of design specifications. These material pairs find a major application in friction clamps of an Inchworm motor resulting in enhancement of force output of the motor. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

During the drilling process, sharp edges of material called burrs are produced and protrude from the original surface. When a through-hole is drilled, burrs form on both the entry and exit surfaces around the hole, requiring expensive deburring operations to be performed in order to meet part specifications. A common hole producing operation in aircraft assembly is drilling holes through multiple sheet metal layers in order to fasten them together. However, at the interface between two layers, burrs form on both the exit of the first layer (termed "skin") and entry of the second layer (termed "frame"). Consequently, the layers frequently need to be taken apart, deburred, and put back together again before being fastened, resulting in additional costs and increased assembly time. The goal of this thesis was to understand the role of key factors such as drill geometry, drill wear and clamping conditions on burr formation at the interface of two thin sheets of 2024-T3 aluminum so that interlayer burr formation could be minimized. This problem was approached from three different angles. First, an experimental study was performed to find the drill geometry parameters for minimization of interlayer burrs and to ascertain the relationship between the average burr size and drill wear. Next, a new kind of clamping system for holding sheet metal layers together during drilling was designed, prototyped, and tested for its effectiveness. Finally, a preliminary analytical model of interlayer burr formation was created in order to better understand the burr formation process in stacked layers of sheet metal and to better understand the effect that each drilling parameter has on the resulting burr size.

Air intake system (AIS) plays an important role on affecting the performance of the engine and the vehicle. The design and optimization of the structures and materials of AIS contributes to producing a quality reliable system, reducing noise, cost and weight at the same time, which are significant to improve the performance of engine and vehicle. Fresh air hoses/pipes are intended to transport, in air cleaner purified, air from the air cleaner to the throttle fitted on the inlet manifold or to the compressor fitted to the exhaust manifold. Air cleaner box is responsible for filtering out the dust and impurities in the air. The charge air pipes are intended to transport purified compressed air from the compressor to the charge air cooler and then to the throttle fitted on the inlet pipe. For the air cleaner box optimization, through the benchmarking and the innovation ideas from the daily life, two alternative optimized designs were introduced to reduce the cost and weight. The first is four clips connectors and the other is spring clamps. For the hose clamps, another innovation design was introduced to replace the previous hose clamps, which is called friction connector on the inner side of the bellow hose, the outer side of the air cleaner box lid and the clean side duct. For the material of the charge air ducts, TPEE was selected to replace the previous EACM rubber hoses. Further tests and prototypes should be conducted and produced to verify the effect of the optimization.

Made available in DSpace on 2014-07-29T15:07:40Z (GMT). No. of bitstreams: 1 Dissertacao_Mestrado_Versao_Pos_Graduacao.pdf: 1271722 bytes, checksum: a118ef7bf5d49deee91d07b7ad899e8c (MD5) Previous issue date: 2012-02-24 / Ovariohysterectomy is the most performed surgery in small animals, with the purpose of birth control, avoiding pseudocyesis as also treating female reproductive tract affections. Several surgery techniques have been described. Beyond the traditional midline approach to the abdomen, the flank many laparoscopic approaches may be performed. Twenty-four healthy, mongrel and adult cats took part of the study. They were randomly distributed in four groups of six animals, this way: GI midline approach and ligature with nylon thread; GII midline approach and ligature with nylon clamp; GIII flank approach and ligature with nylon thread and GIV flank approach and ligature with nylon clamp. The times of dieresis, ovariohysterectomy and closure were timed. Clinic evaluations were done at the day of the surgery and at 7 and 28 days after it. Ultrassonographic evaluations were performed at the day of the surgery, before and after it, and at 7 and 28 days after it, to verify possible alterations related to the material used. The results revealed that the midline approach was significantly faster than the flank approach. The ligature time of the pedicles and uterus body, as the total surgery time were statistically shorter for the groups that used the nylon clamp. We also observed a higher incidence of edema in the groups of midline approach at the seventh day after surgery, however at the twenty-eighth day after surgery, all the wounds healed equally. We concluded that the nylon clamps were secure to be use in cats ovariohysterectomies. Also, the flank approach takes more time to be performed than the midline one. The incidence of edema is considerable higher in the groups of midline access. / A ovário-histerectomia representa um dos procedimentos mais realizados pela clínica de pequenos animais, tendo por finalidade o controle da natalidade, prevenção de cio e pseudogestação, como também, tratar afecções do trato reprodutor feminino. Foram descritas muitas variações de técnicas de ovário-histerectomia, incluindo, além da tradicional abordagem pela linha média, abordagem pelo flanco e diversas abordagens laparoscópicas. Participaram, no presente estudo, 24 gatas hígidas, sem raça definida, adultas, atendidos no Hospital Veterinário da Universidade federal de Goiás. As gatas foram distribuídas aleatoriamente em quatro grupos de seis animais para a realização do procedimento cirúrgico, da seguinte forma: Grupo I - acesso pela linha média e ligadura com fio de náilon; Grupo II - acesso pela linha média e ligadura com braçadeira de náilon; Grupo III - acesso pelo flanco e ligadura com fio de náilon e Grupo IV - acesso pelo flanco e ligadura com braçadeira de náilon. Durante os procedimentos foram cronometrados os tempos de diérese, da ovário-histerectomia em si e de síntese. Avaliações clínicas foram feitas aos sete e 28 dias após a cirurgia. Avaliações utrassonográficas foram realizadas em quatro tempos: antes da cirurgia, imediatamente após, aos sete e aos 28 dias, com intuito de verificar possíveis alterações relativas aos materiais empregados. Os resultados mostraram que o acesso pela linha media foi significativamente mais rápido que pelo flanco. O tempo de ligadura dos pedículos e corpo uterino, assim como o tempo total da cirurgia, foram estatisticamente inferiores nos grupos onde a braçadeira foi empregada. Observou-se maior incidência de edema no grupo de animais onde o acesso foi pela linha média aos sete dias, entretanto aos 28 dias todas as incisões já haviam cicatrizado. As conclusões indicam que as braçadeiras constituem dispositivos seguros, que podem ser utilizados na OHE em gatas. O aceso pelo flanco é, significativamente, mais demorado que pela linha média. Ainda, a incidência de edema foi consideravelmente maior nos grupos em que o acesso à cavidade foi feito pela linha média.

Within the master thesis a computational model of biaxial tension test of soft biological tissues was developed. The tested specimen can be attached using clamps or hooks. The number and the size of clamps and hooks have a significant impact on the distribution of stress and strain in the centre of the specimen, where deformation is measured. Using the developed computational model, a sensitivity analysis of number and size of clamps and hooks and a sensitivity analysis of placement of clamps was elaborated. The number and size of clamps and hooks were optimized in such a way that the material’s parameters obtained by the tension test correspond to the utmost to the actual parameters of the material. By analyzing the placement of clamps, the influence of selected deviations on the outcome of the tension test was determined. Finally, a plan of the next course of action has been proposed.

Il processo infiammatorio è un meccanismo di difesa aspecifico innato, che costituisce una risposta protettiva dell’organismo a vari tipi di insulto (infezione, danno tissutale, trauma, stress, malattie autoimmune,). Esso comporta il rilascio in circolo di mediatori pro-infiammatori (es. citochine) and anti-infiammatori (es lipossine ed alcune citochine). Le citochine pro-infiammatorie inducono effetti infiammatori (es. anoressia e febbre) e stimolano la risposta di fase acuta (APR). Invece, le lipossine e le citochine anti-infiammatorie tendono ad attenuare l’infiammazione. Gli scopi di questa ricerca erano due: distinguere i soggetti in base al grado di severità della APR dopo il parto, e dopo stimolazione intramammaria con lipopolisaccaride (LPS) in bovine da latte sottoposte a diversi stress metabolici (NaCl, BHB, EuG e IpoG). I soggetti EuG e BHB hanno mostrato una APR più severa rispetto a IpoG e NaCl. Un ulteriore scopo è stato proposto un indice composto da alcune proteine di fase acuta al fine di stimare i processi infiammatori e le conseguenze epatiche (PICE). Le bovine con PICE più basso prima del parto, avevano più alti livelli plasmatici di citochine pro-infiammatorie e lipossine prima del parto (e mostravano una APR più severa dopo il parto), anche in assenza di sintomi clinici. / Inflammation is the innate, non-specific response of the host to disturbances in his homeostasis caused by infection, tissue injury, stress, trauma, neoplastic growth, immunological disorders. It involves pro- (e.g. cytokines) and anti-inflammatory mediators (e.g. lipoxins, some cytokines). The pro-inflammatory cytokines induce inflammatory effects (e.g. anorexia, fever) and play key roles in the stimulation of acute phase response (APR). The lipoxins and anti-inflammatory cytokines tend to mitigate the inflammation. Two were the aims of this research: to investigate in dairy cows the severity of APR at calving time as well as after intramammary lypopolysaccharide (LPS) administration in cows challenged with hyperinsulinemic hypoglycemic (HypoG, n=4), hyperinsulinemic euglycemic (EuG, n=5), hyperketonemic (BHB, n=4) and control (NaCl, n=6) clamps. Plasma samples were assayed for a wide metabolic and inflammatory profile. With respect to HypoG and NaCl animals, more severe APR was observed in EuG and BHB. A further aim was the proposal of an Index, composed by several acute phase proteins, to estimate Inflammatory Processes and Hepatic Consequences (IPHC). The dairy cows with lower IPHC after calving, had higher plasma levels of pro-inflammatory cytokines and of lipoxins before calving (and showed a stronger APR after calving); this was seen also in absence of clinical symptoms.