Dissertations / Theses: 'The influence of parameters'

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Anderson, Janet Bradshaw. "Maternal Iron Parameters and Diet: Influence on Infant Iron Parameters and Development." DigitalCommons@USU, 1988. https://digitalcommons.usu.edu/etd/5347.

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The purpose of this study was to determine and evaluate the dietary intake of pregnant women living in this geographical area, evaluate how their diets related to their iron status, how their nutrient intakes compared with other studies, and how their iron status and diet affected infant iron status and development, as assessed by the Bayley Scale of Infant Development. The study involved 32 pregnant women who were between 8 to 14 weeks gestation and 20 to 35 years of age. They were followed through pregnancy and their infants were followed until three months of age. Three-day dietary records, a questionnaire and a blood sample were completed at the initial visit (8 to 14 weeks gestation). Six of the nutrients analyzed were consumed in amounts less than the Recommended Dietary Allowances: iron 77%, magnesium 58%, zinc 51%, vitamin B6 65%, folacin 30% and pantothenic acid 89%. Use of a prenatal vitamin/mineral supplement was beneficial in increasing most of these nutrients to within acceptable range. Zinc was not included in the supplement and thus remained at 51 % of the RDA. Magnesium was increased to 80% of the RDA. Nutrient intakes were very similar to the USDA Nationwide Food Consumption Survey for pregnant women (1985). Mean iron status of the subjects was within acceptable range. A food frequency questionnaire and a blood sample were analyzed at 32 weeks gestation. Iron and vitamin C intake remained fairly constant throughout pregnancy. Fifty-six percent of the subjects had become depleted of iron stores at this time. Cord blood analysis revealed a relationship between maternal iron status and infant iron status at birth. Infant iron status and diet were analyzed at three months gestational stage. Infant iron status appeared to be within normal range. Maternal iron status and diet did not have a significant effect on infant iron status or infant development as assessed by the Bayley Scale of Infant Development.

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Fishman, Benjamin. "Influence of Environmental Parameters on Mold Sampling Results." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6838.

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Mold is a type of fungus present in nearly all environments. Mold thrives under several environmental parameters such as high humidity and an adequate food source. A professional, such as an industrial hygienist, can measure mold in indoor and outdoor environments. Industrial hygienists commonly use a cascade impactor with a culture plate to capture air within a sampling area. While collecting air samples, environmental parameters such as temperature, humidity, and carbon dioxide are recorded. A laboratory then cultures and analyzes the samples, identifying the types and amounts of viable mold found in the sampling area. In this study, a data analysis method is used to interpret lab results and compare those results to the environmental parameters measured during collection. The study aims to show the relationship between the environmental parameters (temperature, humidity, carbon dioxide) and the types and amounts of mold that were measured in both indoor built environments and their surrounding outdoor areas. Among all 170 different sampling locations, the outdoor areas had higher counts and concentrations of mold. In addition, both indoor and outdoor areas saw Penicillium, Aspergillus, and Cladosporium as the most prevalent molds, with Cladosporium having the highest counts. Lower temperatures and humidity had a very small influence on mold growth and thus, yielded the lowest counts. Furthermore, the highest concentrations of mold were found within the same temperature and humidity ranges for both indoor and outdoor environments.

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Dahlin, Anders. "Influence of Ladle-slag Additions on BOF-Process Parameters." Licentiate thesis, KTH, Tillämpad processmetallurgi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-33270.

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The influence of ladle-slag additions on the BOF-process performance were investigated in plant trials. The aim of the study was to recycle ladle slag from secondary steelmaking to the LD-converter to save lime and improve the slag formation. More specifically, two plant trial campaigns covering in total 83 heats, whereof 47 with ladle-slag additions and 36 without ladle-slag additions, were performed. Slag and steel sampling of the process were performed at tapping as well as during blowing at 15, 35, and 65% of the total blowing time. During the first campaign, ladle slag was added through the chute and lime reductions were made manually to correct for the ladle-slag addition. In the second campaign, a development of the approach was made to suite a normal production practice. More specifically, the ladle slag was added through the weight-hopper system and implemented in the process-control system. In this way, the lime additions were reduced automatically by approximately 260 kg per heat. Moreover, the heat balance was compensated with a reduction in the iron-ore consumption. Additionally, the lance program was modified and the lance was lowered in the initial stages of the blow. On the positive side, it was found that no demerits in the metallurgical performance of the process occur when ladle slag is recycled to the BOF-process. Furthermore, only slight affections on the slag composition were found, mainly with respect to the Al2O3 and FeO-content. In addition, the ladle slag was shown to melt during the initial stages of the blow. This contributed to an increased slag weight both during the blow and at tapping. However, a negative effect on the blowing time was experienced during the trials. Although, this effect was more pronounced during the first campaign and could be reduced with a controlled heat balance during the second campaign.
QC 20110503

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Ercan, Saybil Nuray. "The influence of process parameters on filament size distribution." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/ErcanSN2001.pdf.

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Escrig, Josep. "Influence of geometrical parameters on gas-liquid intermittent flows." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/47085/.

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The influence of geometrical parameters on the development of intermittent flow is studied in this thesis. The geometrical parameters considered are the diameter of the pipe, the angle of inclination of the pipe, and the distribution of the area of the gas injection. Intermittent flow in gas-liquid two-phase flows occurs when, from a fixed point, a gas dominated structure followed by a liquid dominated structure seems to repeat at a certain mean frequency. It is mainly slug flow but churn and cap bubble flow also fall into this broad category. Intermittent gas-liquid two-phase flow was investigated in a 67 mm diameter, 6 m long rig and also in a 127 mm diameter, 12 m long rig. The test section of the 67 mm rig was mounted in a steel frame supported by a pivot that allowed changing the inclination of the pipe from vertical to horizontal in steps of 15°. The 127 mm rig can only be operated in the upwards vertical position. The fluids utilised were air and silicon oil of viscosity = 5 cP and density = 0.912 kg/m3. The interfacial surface tension was measured at 0.02 N/m. The facilities were both operated at atmospheric pressure. The gas superficial velocity (Ugs) was varied from 0.17 to 2.9 m/s and liquid superficial velocity (Uls) from 0.023 to 0.47 m/s. The void fraction generated by each set of conditions was captured for 60 seconds using a Wire Mesh Sensor and a twin plane Electrical Capacitance Tomography probe. The effect of the diameter and the angle of inclination of the pipe under different gas and liquid superficial velocities was reported. The main findings can be summarised as that the velocity of the periodic structures was found to be higher in large diameter pipes and increases with increasing the angle of inclination reaching a maximum around 50° then decreases. In addition, the frequency of the gas structures was found to be higher in small diameter pipes and increases with increasing the inclination of the pipe for all the gas and liquid superficial velocities investigated. Additionally, two correlations to predict the velocity and the frequency of the periodic gas structures as a function of the diameter, the inclination of the pipe, the gas superficial velocity and the liquid superficial velocity were developed. The proposed correlations were found to not only be in excellent agreement with the present experimental results (less than 20% difference), but also in good agreement with data published by other researchers. This include data produced using different fluids, different diameters of pipe and different gas and liquid superficial velocities to the ones investigated in this work. It was also found that the gas injection area, modified using different gas-liquid mixers, do not have an influence on the development of the intermittent two-phase flows at 75 diameters axial length from the mixing point.

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Ma, Li. "Influence of experimental parameters on chiral separation in SFC." Thesis, Loughborough University, 1994. https://dspace.lboro.ac.uk/2134/32255.

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This thesis describes an investigation of the chiral separation of two groups of molecules by supercritical fluid chromatography (SFC). The studies were carried out on chiral ChiralCel OB and OD, Cyclobond RN-I and -III and on Pirkle columns using a range of pressure and temperatures from subcritical liquid carbon dioxide to supercritical conditions with or without the addition of methanol (or 2-propanol) as a mobile phase modifier. The first study examined the relationship between structure and resolution for a number of chiral substituted benzyl alcohols and related compounds. The second study examined the benzodiazepines, which have been chromatographed by SFC previously in this laboratory, as examples of fairly polar drugs.

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Ru, Tao. "Spray Parameters Influence on Suspension Plasma Sprayed Zirconia coatings properties." Thesis, Högskolan Väst, Avd för tillverkningsprocesser, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-6960.

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Thermal barrier coatings (TBCs) are a simple and proven method to protect hot section components. Suspension Plasma Spray (SPS), an emerging process technology to generate TBCs, compared with traditional Atmospheric Plasma Spray APS, can deposit thinner coat-ings with finer microstructure. Operating parameters play an important role in developing certain properties of coating. In this thesis work, power level, gas flow rate, number of spray-ing strokes, spray gun's nozzle size i.e. internal diameter and suspension rate were controlled to produce coatings with different microstructures and porosity levels. According to the ex-perimental results, the power level of plasma gun play an essential role on coating micro-structure, for instance, the density of vertical cracks increased with growing the power level. The number of spraying strokes showed also an impact on coating porosity. However, due to different nozzle sizes i.e. diameter, the same coating property were controlled by different operating parameters. For coatings deposited by small and large nozzles, their coating thick-ness and roughness mainly relied on power level and gas flow rate. In contrary, it seems that the coating roughness was not influenced by the same parameters when it was deposited by medium nozzle. Also, gas flow rate do not have as big as influence on coating thickness

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Masini, Alessandro. "Influence of the casting parameters on the membrane morphological characteristics." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23058/.

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During the last century, the importance of membranes has increased drastically in our society; following this trend, their use in everyday life and in the industrial sector has dramatically rised. Consequently, membranes have been object of study in order to develop new material with new characteristics. This work aims at improving a current GVS portfolio-product, by developing a new filter based on alternative material and to substitute a competitor 3 membrane, whose production will be stopped due to the PerFluoroOctanoic Acid content, in a medical device that has to retain human urine. Firstly, the new polymer was studied, in order to understand how it affects membrane properties; once the basic information were obtained, we moved to analyze the influence of all the parameters in the solution preparation and in the casting process. Additionally, we have analyzed and selected the most appropriate membrane support and casting knife, to produce the most reliable membrane. Once we checked all the parameter, a first industrial trial was done based on the knowledge previously obtained; later, the trial has been analyzed to verify the stability of the product and to confirm the success of the industrial scale-up. The industrial trial has been compared with competitors’ membrane after urine test were carried out; the industrial trial showed superior results compared to the other membrane. Later we analyzed the impact of a standard laboratory testing protein on membranes, to observe if they were the main responsible for the pore occlusion after urine contact. Competitor 3 retains the same amount of protein of other membrane, for this reason, the hypothesis previously made was rejected.

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Krtička, J., Joachim Puls, and J. Kubát. "The influence of clumping on predicted O star wind parameters." Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2008/1796/.

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We study the influence of clumping on the predicted wind structure of O-type stars. For this purpose we artificially include clumping into our stationary wind models. When the clumps are assumed to be optically thin, the radiative line force increases compared to corresponding unclumped models, with a similar effect on either the mass-loss rate or the terminal velocity (depending on the onset of clumping). Optically thick clumps, alternatively, might be able to decrease the radiative force.

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Mohajer, Ardavan. "The influence of compost physical parameters on microbial oxygen uptake." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32564.

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The wide range of optimal values reported for the physical parameters of compost mixtures suggest that their interactive relationships should be investigated. The objective of this study was to examine the microbial O2 uptake rate (OUR) in 16 sludge waste recipes, offering a range in moisture content (MC), waste/bulking agent (W/BA) ratio and BA particle size. The 3 kg samples were maintained at a constant temperature and aeration rate for 28 days, during which a respirometer recorded O2 uptake in the different sludge recipes to provide a measure of microbial activity and biodegradability. The cumulative O2 consumption after 14 and 28 days was found to be significantly influenced by MC, W/BA ratio, BA particle size and the interaction between MC and W/BA ratio (P<0.05). Using multivariate regression analysis, the experimental data were used to generate a model capable of predicting average expected cumulative O2 consumption after 28 days as a function of the significant physical variables (R2=0.84). The prediction of O2 uptake by the model depended highly on the interaction between MC and W/BA ratio. The evolution of the OUR in the samples was also investigated for any short and long-term associations in O2 uptake measures. The peak OUR recorded in the samples had a significant association with the cumulative O2 consumption after 14 (R2=0.78) and 28 days (R2=0.57). Moreover, combining peak OUR data with cumulative oxygen consumption after 14 days increased the ability of predicting cumulative O2 after 28 days of aeration (R2=0.96), implying that future studies need only run trials up to 14 days to evaluate the overall O2 consumption or biodegradability of a sludge mixt
Selon plusieurs études, les paramètres physiques ont une influence très variable sur la dégradation de la matière organique pendant le compostage, ce qui suggère un certain niveau d'interaction. L'objectif du présent projet était justement de mesurer l'effet interactif sur la décomposition du compost, de l'humidité (H), du ratio massique de boues d'usine d'épuration et d'agent structurant (B/AS), et de la granulométrie (G) de l'agent structurant composé de résidus ligneux de compostage. Seize (16) recettes de compost, de 3 kg et offrant divers taux de H, B/AS et G, furent chacune incubée à 40 °C dans un respiromètre pendant quatre (4) semaines tout en mesurant leur taux d'assimilation d'oxygène. Les résultats de cette étude ont démontré qu'après 14 et 28 jours, l'assimilation totale d'oxygène était influencée de façon significative par H, le ratio B/AS et la G, ainsi que l'interaction entre le H et le ratio B/AS (p<0.05). Les résultats furent analysés par la méthode statistique d'analyse de régression linéaire multiple afin de générer un modèle capable de prédire la consommation cumulative et moyenne d'oxygène après 14 et 28 jours en fonction des paramètres physiques significatifs citées ci-haut (R2=0.84). L'assimilation d'oxygène des mélanges, telle que prédite par le modèle, est grandement influencée par l'interaction entre le H et le ratio B/AS. L'assimilation cumulative d'oxygène des mélanges à 14 jours (R2=0.78) était plus facile à prédire que celle à 28 jours (R2=0.57). Par contre, la prédiction de l'assimilation d'oxygène devient plus précise à 28 jours lorsque les valeurs mesurées à 14 jours sont inclus

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Voutselas, Vasileios. "The influence of exercise parameters on post-exercise metabolic rate." Thesis, University of Essex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268743.

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Barrie, D. A. "The influence of ship and environmental parameters on stability assessment." Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381518.

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PACHECO, HUGO GUILLERMO JIMENEZ. "SUPERCOOLING OF THE WATER IN CYLINDRICAL CAPSULES: PARAMETERS OF INFLUENCE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12462@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Um dispositivo experimental foi desenvolvido para o estudo do superresfriamento da água em cápsulas cilíndricas visando sua utilização em processos de termoacumulação. A bancada experimental é constituída basicamente por: seção de teste, sistema de resfriamento, sistema de visualização, sistema de aquisição e armazenamento de dados. A temperatura do fluido externo, ou fluido de transferência (FT), uma solução aquosa de álcool a 50% por volume, foimantida constante por um banho de temperatura controlada durante cada teste. O trabalho foi dividido em quatro etapas. A primeira trata do estudo estatístico do super-resfriamento e da nucleação, em que foram utilizados 3 materiais distintos (alumínio, acrílico e PVC) para cápsulas de 30 e 80 mm de diâmetro com diferentes tipos de rugosidade, e diferentes temperaturas do FT. A segunda etapa investiga a Taxa de Resfriamento, parâmetro que quantifica a queda da temperatura e influencia fortemente o super-resfriamento e a nucleação. Na terceira etapa, foi estudada a influência da rugosidade da parede interna da cápsula. Nesta etapa, quatro cápsulas de alumínio distintas, com diferentes rugosidades, foram utilizadas. Finalmente, na quarta etapa foram realizadas visualizações do fenômeno de nucleação. Os resultados obtidos indicam que o material da cápsula (condutividade e rugosidade) e a temperatura do FT têm grande influência nos fenômenos de super-resfriamento e nucleação da água em cápsulas cilíndricas, afetando fortemente o processo de mudança de fase.
An experimental device was developed for the super-cooling water in cylindrical capsules study, seeking its use in term- accumulation processes. The experimental set is constituted basically by: test section, cooling system, visualization system, and data logger system. The temperature of the external fluid, or transfer fluid (FT), an alcohol aqueous solution with 50% per volume, it was maintained unchangeably with a bath controlled temperature during each test. The work was divided in four stages. The first one is about the statistical study of the super-cooling and nucleation, where 3 distinct materials were used (aluminum, acrylic and PVC) for capsules of 30 and 80 mm diameter, different roughness type, with different temperatures of FT. The second stage investigates the Cooling Rate, parameter that quantifies the falling of the temperature and it influences strongly the super-cooling and the nucleation process. In the third stage, the influence of the internal wall of the capsule was studied. In this stage, four different capsules of aluminum, with different roughness were used. Finally, in the fourth stage, visualizations of the nucleation phenomenon were accomplished. The obtained results indicate that the capsule material (conductivity and roughness) and the FT temperature has great influence in the phenomena of super-cooling and nucleation of the water in cylindrical capsules, affecting, strongly, the process of phase change.

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Houbrechts, Jeroen J. J. (Jeroen Jose Julien). "Influence of soil parameters on the motion of rocking walls." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/66835.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 80-81).
Introduced as a system in earthquake engineering in 2004 [6], rocking walls are a fairly new system in earthquake engineering. Their performance has been proven, both in research as in practice. However, a few uncertainties about their behavior still remain. One of these uncertainties is the effect of radiation damping on the motion of the system. Existing estimations for the radiation damping use an equivalent damping ratio, which was actually derived for a rocking block that is not connected to any structure. The formula for this equivalent damping ratio also assumes both the block as the soil to be rigid. The validity of the latter can be questioned. This thesis will research the influence of the flexibility of the soil on the motion of a rocking wall. The influence of the shear wave velocity and the Poisson ratio will be considered. The flexible soil medium is modeled with the finite element method, using a 2D plain strain analysis. In order to be able to use a reasonably fine mesh, the dimensions of the soil island will be small. Viscous boundaries are therefore used to absorb incoming waves. The assumption of a rigid rocking wall is considered to be still valid. Therefore, the motion of the rocking wall is modeled by adding only three degrees of freedom to the finite element model of the soil, applying constraint equations and inserting bilinear springs in the interface between the rocking wall and the soil. The dynamic response will be simulated with an implicit, unconditionally stable time domain method. Results show that the motion of the rocking wall strongly depends on the shear wave velocity. The Poisson ratio has a clear but negligible effect. The simulation also shows that it is, as expected, not valid to estimate an equivalent damping ratio for the rocking wall and using this ratio for the system's response.
by Jeroen J. J. Houbrechts.
M.Eng.

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Barrento, Maria João Hortas. "Influence of soil parameters on ectomycorrhizal diversity in montado ecosystems." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5305.

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Mestrado em Engenharia Florestal e dos Recursos Florestais - Instituto Superior de Agronomia
This study characterized the composition and the diversity of macrofungal communities associated with four plots of montado situated in Grândola Hills, Southern Portugal, and evaluated the influence of soil parameters on ectomycorrhizal fungal diversity and abundance. Phosphorus, potassium, total nitrogen, organic matter concentrations and soil pH were the parameters determined. Differences in soil chemical features were found between studied plots. A total of 132 species of macrofungi were found in the study area being Laccaria, Russula and Cortinarius the most abundant genera. Also dissimilarities on macrofungal communities, particularly, on abundance and diversity, were registered among plots. The influence of soil parameters on ectomycorrhizal diversity and abundance was studied in the plots with values of biological spectrum higher than one, and in particular for the most frequent species Laccaria laccata, Cortinarius trivialis, Russula amoenolens and Russula subfoetens. Results showed that ectomycorrhizal diversity is negatively correlated with the increasing of extractable phosphorus concentration, and the abundance of ectomycorrhizal species responds differently to soil chemical characteristics. The present study allows us to understanding the influence of some soil features on ectomycorrhizal fungal diversity and abundance. Finally, the effects of management practices on ectomycorrhizal fungal diversity in this Mediterranean ecosystem are discussed.

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Greeff, Mary Louise. "The influence of welding parameters on the sensitisation behaviour of 3CR12." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-04052007-124929.

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GARCIA, LUCIENE STIVANIN. "INFLUENCE OF SYNTHESIS PARAMETERS IN THE PROPERTIES OF MCM-22 ZEOLITE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12197@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
A zeólita MCM-22 foi desenvolvida por pesquisadores da Mobil em 1990. É um aluminossilicato com características de peneira molecular e com amplas aplicações em processos catalíticos devido a sua estrutura de dois sistemas de canais independentes. Neste trabalho, as condições reacionais de preparação desta zeólita utilizando tratamento hidrotérmico estático e sob agitação foram estudadas. A composição molar das amostras foi mantida enquanto a temperatura e o tempo de tratamento hidrotérmico ao qual o gel foi submetido foram variados. Os materiais obtidos foram caracterizados usando técnicas analíticas de difração de raios-X com refinamento de Rietveld, adsorção física de nitrogênio (BET), espectroscopia no infravermelho, análise química (espectrometria de absorção atômica), ressonância magnética nuclear (RMN), microscopia eletrônica de varredura e de transmissão. A zeólita MCM-22 característica foi obtida apenas com tratamento hidrotérmico sob agitação. As amostras obtidas a partir do tratamento hidrotérmico estático apresentaram fases como ferrierita, ZSM-5 e quartzo. A morfologia das amostras, observada por microscopia eletrônica de varredura, varia dependendo do tratamento adotado, estático ou sob agitação. Estas diferenças refletem diretamente nas áreas específicas dos materiais. Porém, não se observou diferenças relevantes no volume de poros dos materiais sintetizados sob sistema estático, exceto a amostra obtida com 5 dias de síntese, a qual possui fase amorfa presente. Apesar das fases contaminantes presentes, a microscopia eletrônica de transmissão permite ver o crescimento dos cristais nas três direções. Através dos espectros de infravermelho pode ser observada a eliminação do direcionador orgânico e o caráter hidrofílico da zeólita após o processo de calcinação.
MCM-22 zeolite was first synthesized by Mobil researchers in 1990. It is an aluminosilicate with molecular sieve characteristics and several applications in catalytic processes because of its two independent pore systems. In this work, the MCM-22 zeolite synthesis conditions were studied using both static as stirred hydrothermal treatment. Molar composition of synthesis gel was fixed while the temperature and the gel aging time were varied. The products obtained were characterized using analytical techniques of X-ray diffraction with Rietveld refining, nitrogen adsorption (BET), infrared spectroscopy, atomic emission spectrometry, nuclear magnetic ressonance spectroscopy (NMR), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). Typical MCM-22 zeolite was only obtained from hydrothermal treatment in stirring conditions. Samples obtained by static conditions showed contamination with ferrierita and ZSM-5 zeolites and quartz. The morphology of the samples, as showed by scanning electron micrographs, changed according the conditions of hydrothermal treatment, static or stirring. These differences affected the BET surface areas of obtained samples. However, no differences were observed in pore volume in samples obtained by static system, except the sample synthesized in 5 days, which presented an amorphous phase. Although, there were contaminant phases, transmission electron micrographs permitted to observe the crystal growing in the three directions. Trough infrared spectra it could be observed the template elimination and the zeolite hydrophilic nature after process calcination.

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Chamberlain, Lila Jo. "Influence of implant parameters on the mechanisms of peripheral nerve regeneration." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9893.

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Ebermann, Marko. "Influence of geometric form deviations on operating parameters in hydrodynamic bearings." Technische Universität Chemnitz, 2018. https://monarch.qucosa.de/id/qucosa%3A21225.

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Hydrodynamic plain bearings are important machine elements. They are used in many areas of mechanical engineering, such as turbomachines, crankshaft bearings and gears. The geometry of the lubrication gap elemen-tarily influences the function as shown in several examples of abrupt failures in turbochargers. Due to toleranc-ing, the manufacturing requirements are very high. However, the question remains how large these deviations can be. ISO 12129-2 gives recommendations on form deviations depending on the minimum of plain bear-ing clearance (hmin). Nevertheless, there is no direct reference on the size or the strain on bearing. In DIN 31652-3, the tolerance of the bearing clearance is divided into -1/3 and +2/3 of itself. However, this tolerance merely has an indirect correlation with the size of the bearing and strain on the bearing. If these tolerance recommenda-tions are applied, the function of the plain bearing will not be completely fulfilled. Nonetheless, tolerances pro-vided by standards are used in geometric specifications. If these tolerances are used for in-company manufacturing, this is unproblematic in most cases. But if technical drawings are sent to an external manufacturer, toler-ance limits may be exhausted and the function cannot be ensured. Within the framework of the research project presented here, a tolerance evaluation matrix has been developed. For this, the existing standards were analyzed. In this case, the ignorance of size (diameter and width) and signif-icant operating properties (speed, load, temperature, etc.) are insufficient. The project examined and simulated various possible deviations. Selected form deviations were manufactured. The validation of the simulation results were carried out on 30mm.

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Zemánek, Miroslav. "Influence of Geometrical Parameters on Rupture Risk of Abdominal Aortic Aneurysm." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-233934.

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Tato práce je zaměřena na problematiku výpočtového a experimentálního modelování deformačně napjatostních stavů měkkých tkání se zaměřením na riziko ruptury u výdutě břišní aorty (AAA). V první části (kap. 1) je stručně nastíněn současný stav dané problematiky. Tato část shrnuje důležité poznatky publikované v dostupné literatuře. Pozornost je věnována zejména klíčovým faktorům pro stanovení rizika ruptury AAA. V další kapitole (kap. 2) je stručně popsána histologie cévní stěny a její výsledné mechanické chování, jakož i její patologie, především AAA. Druhá část práce (kap.3) je věnována experimentálnímu vyhodnocování deformačně napjatostního chování měkkých tkání, které je nutným předpokladem k věrohodnému výpočtovému modelování tohoto chování. V této kapitole je stručně popsáno experimentální zařízení speciálně vyvinuté pro testování měkkých tkání a typy zkoušek, které lze na tomto zařízení provádět. Dále jsou shrnuty klíčové faktory ovlivňující deformačně napjatostní chování měkkých tkání a experimentální ověření těchto faktorů na vzorcích z prasečích hrudních aort. V závěru této kapitoly jsou shrnuty nové poznatky vyplývající z experimentálního testování. Třetí část disertační práce (kap.4) je zaměřena na matematický popis deformačně napjatostního chování měkkých tkání, stručný popis používaných konstitutivních vztahu a postup při identifikaci parametrů pro tyto konstitutivní modely určované na základě provedených experimentálních zkoušek. Poslední část disertační práce (kap.5) je věnována výpočtovému modelování deformačně napjatostního chování AAA. V této kapitole jsou nejdříve shrnuty klíčové faktory a předpoklady pro vytváření modelů a pro vyhodnocování výsledku a dále jsou uvedeny materiálové parametry pro konstitutivní modely implementované do programu ANSYS. Byly provedeny testovací výpočty při použití hypotetické zjednodušené geometrie AAA, na kterých byly vyhodnoceny vlivy změny geometrie a vliv změny konsitutivního modelu na extrémní napětí ve stěně AAA. U reálné geometrie AAA byla navržena a otestována metoda výpočtu nezatížené geometrie z reálných CT snímků. Dále byl testován vliv zvýšení vnitřního tlaku jako rizika ruptury AAA. V závěru práce jsou shrnuty poznatky a možnosti výpočtového modelování a návrhy na další práce.

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21

Balakumaran, Soundar Sriram G. "Influence of Bridge Deck Concrete Parameters on the Reinforcing Steel Corrosion." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32665.

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Chloride induced corrosion of steel in concrete is one of the major forms of deterioration mechanisms found in reinforced concrete bridges. Early age corrosion damage reduces the lifespan of the bridges, which results in heavy economic losses. Research has been conducted to identify economic solutions for significantly delaying and/or preventing corrosion damage. Considering the amount of steel reinforcement used in bridge decks, the influence of as constructed parameters including clear spacing between top and bottom reinforcement bars, ratio of cathode to anode areas, and presence of stay-in-place forms on corrosion activity needs to be evaluated. The influence of the as constructed parameters have been studied using different corrosion assessment methods including resistivity, half-cell potential, linear polarization, chloride content, moisture content, and visual inspection. This study included the clear spacing distances between the anode and cathode of 51, 76, and 102 mm (2, 3, and 4-inch), number of cathodes as 1 and 2, and the presence and absence of stay-in-place forms. Data up to 15 months were taken from a previous study by Smolinski and integrated into the current study period of 35 to 45 months. A trend line may be established to illustrate the changes which took place over the missing time period, from approximately 15 to 35 months, since the specimens were maintained in controlled environment. Analysis of the data showed that there is a significant difference between the spacing values (2, 3, and 4-inch) through all forms of evaluations. Regarding the other parameters, no significant difference was identified. Variations in resistivity with increasing spacing, even when the water-cement ratio was kept at 0.50, maybe the result of the difference in unit consolidation between the clear spacing specimens. Thus, the corrosion mechanism observed in this study may be resistivity-controlled. Also, autopsy showed that corrosion on the top bars was in general agreement with the measured corrosion activity. The bottom bars had no visible corrosion and the chloride had not penetrated to the bottom bars, regardless of the separation distance between the top and bottom bars. For this laboratory study, the measurements showed that macrocell corrosion influence on the total corrosion was insignificant.
Master of Science

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22

Sreekanth, Suhas. "Laser-Directed Energy Deposition : Influence of Process Parameters and Heat-Treatments." Licentiate thesis, Högskolan Väst, Avdelningen för svetsteknologi (SV), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-15767.

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Laser-Directed Energy Deposition (L-DED), an Additive Manufacturing (AM) processused for the fabrication of parts in a layer-wise approach has displayed an immense potential over the last decade. The aerospace industry stands as the primary beneficiary due to the L-DED process capability to build near-net-shape components with minimal tooling and thereby producing minimum wastage because of reduced machining. The widespread use of Alloy 718 in the aero-engine application has prompted huge research interest in the development of L-DED processing of this superalloy. AM processes are hindered by low build rates and high cycle times which directly affects the process costs. To overcome these issues, the present work focusses on obtaining high deposition rates through a high material feed. Studying the influence of process parameters during the L-DED process is of prime importance as they determine the performance of in-service structures. In the present work, process parameters such as laser power, scanning speed, feed rate and stand-offdistances are varied and their influence on geometry and microstructure of Alloy 718 single-track deposits are analyzed. The geometry of deposits is measured in terms of height, width and depth; and the powder capture efficiency is determined by measuring areas of deposition and dilution. The microstructure of the deposits shows a column ardendritic structure in the middle and bottom region of the deposits and equiaxed grains in the top region. Nb-rich segregation involving laves and NbC phases, typical of Alloy718 is found in the interdendritic regions and grain boundaries. The segregation increases along the height of the deposit with the bottom region having the least and the top region showing the highest concentration of Nb-rich phases due to the variation in cooling rates. A high laser power (1600 W – 2000 W) and a high scanning speed (1100 mm/min) are found to be the preferable processing conditions for minimizing segregation. Another approach to minimize segregation is by performing post-build heat treatments. The solution treatment (954 °C/1 hr) and double aging (718 °C/8 hr + 621 °C/ 8 hr) standardized for the wrought form of Alloy 718 is applied to as-built deposits which showed a reduction in segregation due to the dissolution of Nb-rich phases. Upon solution treatment, this reduction is accompanied by precipitation of the delta phase, found predominantly in top and bottom regions and sparsely in the middle region of the deposit.

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23

Weidle, William Scott. "Influence of Trimaran Geometric Parameters on Intact and Damaged Ship Stability." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/81101.

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Multi-hull vessels have been considered for high-speed, military and commercial applications for decades. More recently the trimaran vessel, with three hulls, has captured interest among naval ship designers and stakeholders. A definition of multi-hulls is introduced as a continuum with monohulls on one end, catamarans on the other, and trimarans in-between. A review of methods to assess intact and damaged stability follows in addition to an overview of current research in the area of dynamic stability for monohulls and trimarans. An investigation of intact stability characteristics for multi-hulls along the continuum is presented and their trends are examined. Next, a series of trimaran configurations are modeled in CAD with subdivision to determine their allowable KG according to USN deterministic criteria and using quasi-static methods. A response surface model was determined for allowable KG as a function of center hull length to beam, side hull beam to draft, transverse position, and displacement for use as a rule of thumb measure and potential optimization constraint.
Master of Science

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24

Gopalakrishnan, Pradeep. "Influence of Laser Parameters on Selective Retinal Photocoagulation for Macular Diseases." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1121436799.

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25

Wilson, Andrew. "The influence of laser parameters on the surface processing of materials." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810645/.

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Laser beams have a vast range of applications, from optical drives for CDs and DVDs, to large scale laser cutting and drilling processes. Lasers have also been used in the past for surface modification of materials, and laser ablation mechanisms. This work focused on two regimes of laser power intensity, using a Nd:YAG nanosecond pulsed laser for lower power intensity and a picosecond pulsed diode pumped Yb-doped fibre laser for higher power intensity. Using the lower power intensity, studies were undertaken on the surface modification of PP and PEEK material, intended for increased adhesion strength of the materials bonded together in a lap shear configuration. Treated surfaces were examined by CLSM, contact angle analysis, FT-IR, XPS, and ToF-SIMS, and were tested in single lap shear tests. It was found that laser surface treatment improved the surface energy (44.9 mJ m-2 to 72.5 mJ m-2 in the case of PEEK and 32.5 mJ m-2 to 57.5 mJ m-2 in the case of PP) and wettability of the treated surfaces. This lead to improved adhesion strength in the lap shear tests. The higher power intensity provided by the picosecond pulsed laser was used to strip the active layers and coating materials from photovoltaic fibres and energy storage fibres with a copper core conductor, with the intention of exposing the copper for subsequent electrical interconnection. The treated samples were examined by focus variation microscopy, SEM, XPS and electrical continuity measurements. It was found that the coatings could be successfully stripped using a wavelength of 532 nm, pulse repetition rate of 100 kHz, 2 passes, a sample angle of 90°, and a scanning speed of 100 mm s-1. This exposed the copper conductor and maintained electrical continuity.

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26

Dores, Ana Cristina Heitor Machado. "Influence of overweight on routine parameters of renal function in dogs." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2018. http://hdl.handle.net/10400.5/15747.

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Dissertação de Mestrado Integrado em Medicina Veterinária
Obesity is one of the most common nutritional disorders in dogs and its prevalence has grown exponentially in recent years alongside with obesity in humans. It is from an accumulation of adipose tissue in such a way that it affects the patient health. In humans, a chronic increase of body weight is a risk factor to develop renal dysfunction. Therefore, the purpose of this study was to investigate the effect of weight gain on renal function in dogs. Renal function was determined using traditional markers of renal dysfunction (blood urea nitrogen and creatinine, urine specific gravity and urine protein-creatinine ratio). A total of 16 beagles were studied, 8 non-obese, which kept a stable ideal body weight, and the remaining 8, gradually increased weight for 24 weeks. Both groups were fed a commercial adult maintenance diet high in fat and protein. The obese group was fed 1.3 times more than the maintenance energy requirements, resulting in an average of 0.328 kg increase in weight per month. Renal markers were measured at times 1, 12 and 24 weeks and the results did not showed a significant difference between the groups. These results suggest that the degree of overweight that was achieved in this study did not cause renal dysfunction based on routine kidney markers.
RESUMO - A INFLUÊNCIA DO EXCESSO DE PESO EM PARÂMETROS DE AVALIAÇÃO DA FUNÇÃO RENAL DE ROTINA - A obesidade, uma das doenças nutricionais mais comuns em cães tendo a sua prevalência crescido exponencialmente nos últimos anos, a par com a obesidade nos humanos. É uma doença crónica que advém do excesso de acumulação de tecido adiposo de tal forma que afeta a saúde. No homem, uma condição corporal aumentada é um fator de risco para disfunção renal. O objetivo deste estudo foi investigar o efeito do aumento de peso sobre a função renal em cães. A função renal foi determinada através de marcadores renais convencionais de insuficiência renal (ureia e creatinina sérica, densidade urinária, rácio proteína-creatinina de urina). Um total de 16 beagles foram usados, 8 não obesos que mantiveram um peso corporal estável, e os 8 restantes, que aumentaram progressivamente o peso durante 24 semanas. Ambos os grupos foram alimentados com uma dieta comercial de manutenção, rica em gordura e proteína. Ao grupo obeso foi fornecido 1,3 vezes mais que os requisitos energéticos de manutenção, fazendo com que este grupo aumenta-se 0,328kg mais por mês. Os marcadores renais foram medidos às 1, 12 e 24 semanas em ambos os grupos, não tendo demonstrado diferenças significativas, sugerindo que o grau de excesso de peso obtido neste estudo não causa alterações na função renal.
N/A

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27

Jalilian, Farzad. "The influence of process parameters on TLP bonding of Inconel 617 superalloy /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102512.

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Joining of superalloy Inconel 617 using a foil interlayer with transient liquid phase bonding (TLP) was studied. Inconel 617 is a solid solution, Ni-Cr-Co-Mo alloy with an exceptional combination of high temperature strength, oxidation and carburization resistance and thermal stability.
Two types of interlayer compositions for the TLP bonding process were selected. Specifically, boron containing (AWS BNi-3) and phosphorus rich (AWS BNi-6) were employed as melting point depressant (MPD) elements. Process parameters such as bonding temperature, holding time, composition and thickness of interlayer were selected for study. Two bonding temperatures, 1065°C and 1150°C, and two interlayer thicknesses with various holding times ranging from 5 minutes to 24 hours were selected.
Joints were fabricated using Inconel 617 specimens measuring 25 mm long, 5 mm wide and 1 mm thick. A tube furnace under vacuum (1 x 10-5 mbar) was used to carry out the experiments. The specimens were fixed with stainless steel fixture and held at the bonding temperature for the selected times.
Optical microscopy, SEM, FEG-SEM, VP-SEM were used to follow microstructure evolution and identify its constituents. The microstructure of the joint area, formation and dissolution of precipitates and the evolution of the base metal grain size with holding time for the two bonding temperatures and interlayer thickness were also characterized using the above techniques. TEM, EBSD and XRD techniques were employed to identify the phases such as borides, carbides, phosphides and other precipitates in the joint area. Microhardness tests of the joint were performed to investigate relationships between microstructure and mechanical properties of the joint. A critical review of the existing theoretical models for isothermal solidification of the TLP bonding was carried out and their application to the obtained results for Inconel 617 was assessed.

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28

Lindström, Mikael. "Injector Nozzle Hole Parameters and their Influence on Real DI Diesel Performance." Licentiate thesis, KTH, Machine Design (Div.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9929.

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A modern diesel engine is capable of running efficiently with low exhaust gas emissions over a wide operating range. This is thanks to techniques such as turbocharging, EGR, charge air cooling and an advanced fuel injection process. The fuel injection process is important for the combustion and emission formation in the diesel engine. The fuel injector has to atomize and vaporize the fuel as it is injected. During the combustion the emission formation has to be kept to a minimum. Very strong pressure gradients are present in a modern diesel injection nozzle, this causes cavitation to occur in the nozzle holes. The influence of cavitation on flow parameters such as the various discharge coefficients is discussed. The occurrence of cavitation helps the spray break up and it can keep the nozzle holes free from deposits. Excessive amounts of cavitation can lead to hole erosion and thus impact the long term operation of the nozzle in a negative way. Hole erosion as well as other mechanisms can cause hole to hole variations in fuel spray impulse, mass flow, penetration etc. This is a very important issue in any low emission diesel engine, especially during transients, as less than optimal conditions have to be handled. The influence of hole to hole variation on fuel consumption and emissions is not very well known and this thesis contributes to the field. As a part of this work a fuel spray momentum measurement device was developed and tested. Any automotive engine needs to be able to perform quick transitions between different loads and speeds, so called transients. In a turbocharged diesel engine with EGR issues related to the turbocharger and the EGR-circuit arise. A diesel engine has to run with a certain air excess in order to achieve complete combustion with low emissions of soot. When turbocharging is used the turbocharger turbine uses some of the exhaust enthalpy to drive the turbo compressor, in this way the engine is provided with boost pressure. In order for the engine and turbocharger to function at the higher load and thus higher mass flow rate the turbocharger has to increase its rotational speed and the surface temperatures have to settle at a new thermodynamic state. Both of these processes take time and during this time the combustion process may have to proceed under less than optimum circumstances due to the low boost pressure.

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29

Van, Voorhies Wayne Alan. "The influence of metabolic rate, temperature and sex on life history parameters." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186564.

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My dissertation research focused on four major biological variables; metabolic rate, body size, sex, and death. I found that growth and metabolic rate are not significantly correlated in the fish Oreochromis hybrid. To study factors affecting body size I researched the causal mechanism of Bergmann size clines. This is the trend that organisms tend to increase in body size with increasing distance from the equator. I found that genetically identical nematode worms, Caenorhabditis elegans, grow almost 40% larger at 10°C than at 25°C. Since adult worm cell number is constant in these worms the larger worm size is probably due to increased cell size. This provides a simple developmental mechanism, cells grow larger at lower temperatures, for Bergmann size clines in ectotherms. This would provide a simple non-adaptive explanation for the general trend of increased body size in ectothermic animals with increasing latitude. Sex significantly decreases the average lifespan of wild type male C. elegans but does not significantly affect hermaphrodite lifespan. I compared lifespans in three groups of worms: (1) all males, (2) all hermaphrodites, (3) a mixed population of hermaphrodites and male worms. At 20°C unmated males have an average lifespan 33% greater than mated males. In contrast, lifespans of mated and unmated hermaphrodites were identical. This result contradicts theories concerning the relative cost of reproduction which predict that large oocytes should be much more costly to produce than small sperm. I examined the lifespan of worms with a mutation affecting sperm production to determine if sperm production, rather than the physical effort of mating, is the major factor reducing lifespan in mated male worms. Average lifespan of both mutant mated males and unmated hermaphrodites is about 65% longer than that of wild type worms. Mated spe-26 males have similar lifespans to their unmated counterparts. These surprising results indicate that sperm production rather than ooycte production or the physical effort of mating is a major factor reducing lifespan in C. elegans.

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30

Mancino, C. F., L. Salo, A. Hayes, I. Pepper, and D. M. Kopec. "The Influence of Effluent Irrigation on Specific Soil Microbial Populations and Parameters." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/215852.

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31

Yung, Joanne, and 容靜雯. "Auditory-verbal rehabilitation: influence of the hand cue technique on acoustic parameters." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B3047145X.

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32

Kellerman, Stephanie, and S. J. Schoeman. "The influence of dietary protein levels on growth curve parameters of quail." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/830.

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Thesis (MPhil (Agrisciences)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: In South Africa quail do not have the same status as an agricultural produce as do other livestock species. As quail has mostly been judged as a cute little bird seen on shows, very few people have paid attention to the commercial value of this bird specie. In South Africa quail farming is done on a very limited scale, but competition regarding this very unique market is already challenging. If it is to be a viable project it is of utmost importance to limit the costs to the minimum and, by doing so, increasing the profitability of the project. In this study the economic aspects of a quail production unit was researched to assess whether any improvements in profitability could be made. Quails from a production unit outside Stellenbosch were used to describe the growth curves of these birds under three different diet regimes. 300 Birds were used and then divided into groups of a hundred. The first treatment was fed the standard starter (22% protein) then after five weeks a finisher (19% protein). The second treatment was fed a starter ration containing 40% Soya oil cake and 60% of the standard starter (27.2% protein). The same finisher as in treatment one was fed to treatment two after five weeks. Treatment three was fed a newly formulated starter ration (28% protein). The same finisher was fed to treatment three after five weeks as with the first two treatments. It was found that treatments one and two differed significantly from treatment three, but not from each other. It was expected that treatment three would result in better growth than treatment one, but contrariwise, treatment three did the worst. In accordance with literature it was found that under commercial conditions quail could be fed lower concentrations of protein than prescribed by literature.
AFRIKAANSE OPSOMMING: As 'n landbouproduk het kwartels in Suid-Afrika nie dieselfde status as ander lewende hawe nie. Omdat kwartels merendeels gesien is as 'n oulike klein voeltjie op skoue, het weinig mense enige aandag gegee aan die kommersiele waarde van kwartels. Alhoewel kwartelboerdery in Suid-Afrika huidiglik slegs op 'n baie klein skaal bedryf word, is kompetisie in hierdie nismark reeds kompeterend en uitdagend. Om so 'n boerdery ekonomies vatbaar te maak en hoe profyt marges te handhaaf, is dit van wesenlike belang om insetkostes tot die minimum te beperk. In hierdie studie is ekonomiese aspekte van 'n kwartel produksie eenheid nagevors om sodoende te kon bepaal op watter aspekte, indien enige, gekonsentreer kan word om wins marges te verhoog. Kwartels van 'n produksie eenheid buite Stellenbosch is gebruik. Hierdie kwartels is op drie verskillende diete geplaas en afsonderlik ge-evalueer om die groeikurwes op elke dieet te bepaal. Driehonderd kwartels is in groepe van honderd elk verdeel. Die eerste groep se dieet het bestaan uit die standaard beginners groeimeel wat deur Meadows vervaardig word (22% proteren), en is na vyf weke afgerond na 'n afrondings dieet (19% proteren). Die tweede groep se dieet was dieselfde beginners dieet as in groep een wat met 40% Soya oliekoek gemeng is (totale proteren inhoud van 27.2%). Daar is na vyf weke oorgeslaan na dieselfde afrondings dieet as in groep een. Die derde dieet het bestaan uit 'n nuut geformuleerde beginners dieet (28% proteren). Weereens is daar na vyf weke oorgeslaan na dieselfde afrondings dieet as in die vorige twee groepe. Daar is gevind dat die groeikurwes van diete een en twee beduidend verskil het van dieet drie, maar daar was nie 'n beduidende verskil tussen groepe een en twee nie. Alhoewel daar verwag is dat dieet drie 'n beter groeikurwe sou toon as dieet een, was dit egter nie die geval nie. Dieet drie het egter die swakste groeikurwe getoon. Daar is dus gevind dat kwartels onder kommersiele toestande laer konsentrasies proteren gevoer kan word as wat algemeen voorgeskryf word.

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33

Joubert, Retief. "Influence of geometric and environmental parameters on air-cooled steam condenser performance." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4153.

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Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Air-cooled steam condensers (ACSCs) are used in the power generation industry to directly condense turbine exhaust steam in areas where cooling water is expensive or unavailable. Large axial flow fans force ambient air through A-frame heat exchanger bundles made up of a number of rows of finned tubes through which the steam is ducted and consequently condensed during the heat transfer process to the air. The heat rejection rate or performance of an ACSC is proportional to the air mass flow rate, determined by fan volumetric performance, and the temperature difference between the finned tubes and the air. The air flow through a 30 fan ACSC (termed the generic ACSC) operating under windy conditions is solved using the commercial computational fluid dynamics (CFD) code FLUENT and the required data is extracted from the solution to calculate performance trends. It is found that fan performance is reduced due to a combination of factors. The first is additional upstream flow losses caused by separated flow occurring primarily at the leading edge of the ACSC and secondarily at the fan bellmouth inlets. The second factor leading to reduced fan performance is the presence of distorted flow conditions at the fan inlets. Hot plume air recirculation is responsible for decreased ACSC thermal performance due to increased fan inlet air temperatures. It is found that reduced fan performance is the greater contributor to reduced ACSC performance. The performance effects of varying two geometrical parameters of the generic ACSC, namely the fan platform height and the windwall height, are investigated under windy conditions. It is found that each parameter is linked to a specific mechanism of performance reduction with the fan platform height affecting fan performance and the windwall height affecting recirculation. The respective platform and windwall heights specified for the generic ACSC are found to provide acceptable performance results. To mitigate wind induced performance reductions a number of modification and additions to the ACSC are investigated. These primarily aim at improving fan performance and included the addition of walkways or skirts, the addition of wind screens beneath the fan platform, removing the bellmouth fan inlets, using different types of fans and increasing fan power. The addition of a periphery walkway and windscreens is considered to be the most practical methods of improving ACSC performance under windy conditions. The generic ACSC is modified to include both modifications and under high wind conditions the performance is found to increase measurably. The modifications also resulted in the ACSC performance being less sensitive to wind direction effects.
AFRIKAANSE OPSOMMING: Lugverkoelde kondensators word in die kragopwekkings industrie gebruik om turbine uitlaatstoom te kondenseer, veral in gebiede waar verkoelingwater duur of onbeskikbaar is. Aksiaalvloei-waaiers forseer omgewingslug deur A-raam warmteuitruiler bondels wat bestaan uit verskeie rye vinbuise. Die uitlaatstoom vloei in die vinbuise en kondenseer as gevolg van die warmteoordrag na die lug. Die warmteoordragkapasiteit van die lugverkoelde stoom kondensator is eweredig aan die massavloei-tempo van die lug, wat bepaal word deur die waaierwerkverigting, en die temperatuur verskil tussen die vinbuise en die lug. Die lugvloei deur 'n 30 waaier lugverkoelde stoom kondensator (genoem die generiese lugverkoelde stoom kondensator) onderworpe aan winderige toestande word opgelos deur die gebruik van die kommersiële vloeidinamika-pakket, FLUENT. Die nodige data is onttrek uit die oplossing en werkverrigting neigings is bereken. Dit is gevind dat waaierwerkverigting verminder as gevolg van 'n kombinasie van faktore. Die eerste is bykomende vloeiverliese wat veroorsaak word deur vloeiwegbreking wat plaasvind primêr by die voorste rand van die lugverkoelde stoom kondensator asook by die klokvormige waaier-inlate. 'n Tweede faktor wat lei tot vermindere waaierwerkverigting is die teenwoordigheid van lugvloeiversteurings by die waaier-inlate. Hersirkulering van warm pluim lug is ook verantwoordelik vir verminderde lugverkoelde stoom kondensator werkverrigting. Daar word bevind dat die vermindering in waaierwerkverrigting die grootste bydraende faktor tot vermindere lugverkoelde stoom kondensator werkverrigting is. Die effek van verandering van twee geometriese lugverkoelde stoom kondensator parameters, naamlik die waaierplatformhoogte en die windwandhoogte is ondersoek onder winderige toestande. Daar word bevind dat elk van die parameters gekoppel is aan 'n spesifieke meganisme van vermindere lugverkoelde stoom kondensator verrigting: Die waaierplatformhoogte beïnvloed waaierverrigting terwyl die windwandhoogte hersirkulering beinvloed. Daar word ook bevind dat die onderskeie waaierplatform- and windwandhoogtes van die generiese lugverkoelde stoom kondensator, van so 'n aard is dat dit aanvaarbare werkverrigting tot gevolg het. Om verlaging in werksverrigting in winderige toestande te verminder is verskeie modifikasies en byvoegings tot die lugverkoelde stoom kondensator ondersoek wat primêr gemik is op verbetering in waaierwerkverigting. Die ondersoek dek die byvoeging van 'n loopvlak, die byvoeging van windskerms onder die waaierplatform, verwydering van die klokvormige waaier-inlate, die gebruik van verskillende waaiers en die verhoging van waaierdrywing. Daar was besluit dat die byvoeging van 'n loopvlak rondom die rand van die lugverkoelde stoom kondensator en die byvoeging van windskerms die mees praktiese manier was om die lugverkoelde stoom kondensator verigting te verbeter. Die generiese lugverkoelde stoom kondensator was aangepas om beide veranderings in te sluit en meetbare verbetering in werkrigting was verkry. Die veranderings het ook meegebring dat die lugverkoelde stoom kondensator minder sensitief is vir windrigting effekte.

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Serra-Stepke, Ignacio M. "Influence of soil parameters and canopy structure on root growth and distribution." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4184.

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Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Because of long-term climate changes, apparently associated with higher temperatures and fewer rainfall events, factors such as water-use efficiency and site selection for new cultivars are a matter of increasing importance for viticulture. Within this context, the root system is expected to play a key role. Its relevance to grapevine functioning is due to the numerous functions in which it is involved. In the light of this, the development of the root system is highly relevant to the viticulturist because of the fact that grapevine growth and functioning are dependent on the development of the root system. Differences can, therefore, be expected in terms of berry ripening on single grapevines of the same scion for situations with differing development of root systems, despite being grafted on the same rootstock. Root growth is influenced by several factors, among the ecological aspects. Soil parameters have a predominant influence on root growth and distribution but also annual root production can be altered by canopy manipulation. Due to the importance of root growth to the aboveground development of the vine, it is critical to gain understanding of the relationship between soil factors and root growth and distribution, and the central role that the subterranean environment plays in the concept of terroir. This study aimed to investigate the effect of selected soil physical and chemical parameters on root growth and distribution and to investigate whether having very different canopies influences root growth. In order to achieve these goals, two experiments were conducted; the first was performed in two commercial Sauvignon blanc vineyards each grafted onto Richter 110, non-irrigated, with two treatments: undisturbed lateral growth and complete lateral removal. The second study included the analysis of eight commercial Sauvignon blanc vineyards grafted onto Richter 99 and Richter 110 located in the Stellenbosch Wine of Origin District. Measurements of physical and chemical soil parameters, root growth and distribution, canopy growth and functioning, vine water status and berry composition were performed. The edaphic factors appeared to be one of the most important parameters that affected root development by changing soil water availability and possibly causing physical or chemical limitations on root growth. From the results of this study, it is clear that severe water stress and a pH (KCl) lower than 4.5 play a key role in the limitation of root growth. Due to the fact that most of the soils from the Stellenbosch Wine of Origin District, especially the subsoils, are acidic, this is a factor to consider before planting. On the other hand, the combination of favourable edaphic conditions, such as a subsoil pH of higher than 5.0, light- to mediumtextured subsoil and moderate water stress, allow increased growth of thin roots. However, the effect of canopy management on root growth cannot be discounted due to its importance in the variation of carbohydrate demand by competing sinks. This study showed that lateral removal done from when the berries are at pea size results in an increase in the number of thin roots (0.5-2.0 mm). The secondary leaf area represents at least the same leaf area as the primary leaf area in all the vineyards evaluated, which reveals the relative importance of the laterals in the total leaf area of the vine and the potential importance in terms of microclimate and leaf area available for photosynthesis. Studies of root growth should take the vineyard canopy architecture into account.
AFRIKAANSE OPSOMMING: As gevolg van langtermyn klimaatsveranderinge wat toegeskryf kan word aan die voorkoms van hoër temperature en laer reënval, is faktore soos effektiwiteit van waterverbruik en liggingseleksie vir nuwe kultivars van kardinale belang vir wingerdkunde. Binne hierdie konteks, speel die wortelsisteem ‘n belangrike rol. Die belangrikheid hiervan vir wingerdfunksionering kan toegeskryf word aan die talle funksies waarby dit betrokke is. Die ontwikkeling van die wortelsisteem is dus hoogs relevant vir die wingerdkundige, omdat wingerdgroei en funksionering afhanklik is van die ontwikkeling van die wortelsisteem. Verskille kan daarom dus verwag word in terme van korrelrypwording op ‘n enkele wingerdstok van dieselfde onderstok vir gevalle met verskillende ontwikkeling van die wortelsisteem, ten spyte daarvan dat dit op dieselfde onderstok geënt is. Wortelgroei word, onder ekologiese aspekte, deur verskillende faktore beïnvloed. Grondfaktore het meerendeels ‘n predominante invloed op wortelgroei en -verspreiding, terwyl jaarlikse wortelproduksie deur lowermanipulasie beïnvloed kan word. Weens die belangrikheid van wortelgroei vir die bogrondse ontwikkeling van die wingerd, is dit krities om kennis op te doen oor die verhouding tussen grondfaktore en wortelgroei en –verspreiding, asook die sentrale rol wat die subterreinomgewing op die terroir-konsep speel. Die studie was daarop gemik om die invloed van geselekteerde fisiese en chemiese parameters van grond op wortelgroei en -verspreiding vas te stel, en ook te ondersoek of verskillende lowers wortelgroei sal beïnvloed. Om laasgenoemde doelwitte te bereik, is twee eksperimente uitgevoer. Die eerste is uitgevoer in ‘n kommersïele Sauvignon blanc-wingerd wat geënt is op Richter 110, sonder besproeïng en met twee behandelings, naamlik onversteurde sêkondere lootgroei en volledige sêkondere lootverwydering. Die tweede studie het die analise van agt kommersïele Sauvignon blancwingerde geënt op Richter 99 en Richter 110 in die Stellenbosch Wyn van Oorsprong Distrik. Metings van fisiese en chemiese grondfaktore, wortelgroei en -verspreiding, lowergroei en -funksionering, plantwaterstatus en korrelsamestelling is uitgevoer. Dit blyk dat edafiese faktore een van die belangrikste parameters is wat wortelontwikkeling beïnvloed deur beskikbaarheid van grondwater te verander, en wat moontlik fisiese en chemiese beperkings op wortelgroei kan veroorsaak. Uit die resultate van die studie is dit duidelik dat intense waterspanning en ‘n pH (KCl) laer as 4.5 ‘n belangrike rol in die beperking van wortelgroei speel. Aangesien die meeste van die grondsoorte in die Stellenbosch Wyn van Oorsprong Distrik, veral al die subgronde, suur is, is dit ‘n faktor wat in oorweging geneem moet word voor aanplantings. Die kombinasie van gunstige edafiese toestande, soos ‘n subgrond met ‘n pH hoër as 5.0, ‘n lig tot medium tekstuur en matige waterspanning, sal dus aanleiding gee tot ‘n toename in die groei van dun wortels. Die effek van lowerbestuur op wortelgroei kan egter nie buite rekening gelaat word nie weens die belangrikheid daarvan in die variasie van koolhidraataanvraag deur kompeterende vraagpunte. Hierdie studie toon dat, indien sêkondere lootverwydering tydens ertjiekorrelgrootte toegepas is, dit aanleiding gee tot ‘n toename in die dun wortels (0.5 tot 2.0 mm). Die sêkondere blaaroppervlakte verteenwoordig minstens dieselfde blaaroppervlakte as die primêre blaaroppervlakte in al die wingerde wat ondersoek is, wat dui op die belangrikheid van sêkondere lote in die totale blaaroppervlakte van die wingerd en die potensiële belangrikheid daarvan in terme van mikroklimaat en blaaroppervlakte wat vir fotosintese beskikbaar is. Studies van wortelgroei moet lowerargitektuur in ag neem.

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Makaronidis, Georgios. "Influence of growth parameters on the structural quality of MOCVD grown GaN." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616243.

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Ayadh, Mohammed Thabet. "Influence of the city geometric features on the two fluid model parameters." Thesis, Virginia Tech, 1986. http://hdl.handle.net/10919/45683.

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The traffic flow in an urban street network is a complicated system which involves many variables. Some of these variables relate to the networkâ s geometric features; some of these variables reflect the characteristics of the vehicles, drivers and pedestrians using the network.

The Two Fluid Model was introduced to help evaluate the quality of traffic service in urban street networks. The model parameters, T_m and n, are used as a scale to compare traffic quality in two or more urban street networks. It is known that the higher the values of the two parameters in a network, the lower the quality of the network's traffic service.

This report presents material which may be used to predict the correlation between the Two Fluid Model parameters and the geometric features of a specific street network.

The Two Fluid Model parameters will be used as dependent variables in this analysis. Seven network geometric features were selected to be used as independent variables. Using linear regression techniques, the variables will be analyzed to formulate two models. One model will explain the relationship between Tm and corresponding geometric features; the other model will explain the relationship between T_m and its corresponding features. A basic understanding of these two models will allow traffic engineers to develop strategies and/or network changes to improve traffic service in a city's street network. This will especially help networks still in the planning and/or design stage.

Because the trip time per unit distance, T, is an important traffic variable for both the Two Fluid Model and in fuel consumption models, portions of this report concentrated on establishing a relation between the two models.

Master of Science

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Smolinski, Laura J. "Influence of Reinforcing Steel Parameters on the Formation of the Passive Layer." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31323.

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Corrosion in reinforced concrete bridge decks has always been a concern amongst engineers. However, as structures continue to increase in size and in the amount of reinforcement present, consideration must be given to parameters such as the clear spacing arrangements between bars, the presence and absence of stay-in-place (SIP) forms, and differences in the cathode bar to anode bar ratios. Limited research has been performed to determine the effects of the parameters (Shiessel, P. 1986). Research has been conducted on the effects of macrocell corrosion compared to microcell corrosion. Previous studies have shown that the measured microcell corrosion is not augmented greatly by the macrocell current (Andrade et al. 1991). In this study, twenty-seven specimens were cast with reinforcing steel to represent reinforcing mats at the top and bottom of each specimen. Top and bottom spacing arrangements were approximately 51, 76, 102 mm (2, 3, and 4-inches), cathode-to-anode bar (C/A) ratios were 2 and 1, and the presence and absence of SIP were considered. Macrocell currents, resistivity measurements, half-cell potential measurements, and corrosion current densities were recorded over a 273 day time period to compare the differences that existed amongst the three different parameters. Based upon the data that was collected, no significant differences were recorded when comparisons were made between the spacing arrangements, the absence and presence of SIP, and differences in C/A ratios. The formation of the passive layer was confirmed by the corrosion current densities and half-cell potentials. The rate of the formation of the passive layer occurred in two distinct periods, a rapid rate from casting to about 105 days and a significantly slower rate beyond 105 days after casting. There was no detected influence of the macrocell activity on the formation of the passive layer throughout the 273 day study period.
Master of Science

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Jarmul, Edward S. "Investigation of interface parameters that influence the electromechanical transfer of tactile information /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487678444259659.

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Angelucci, Matteo. "The influence of mix design parameters and compressive strenght on durability indices." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/9990.

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Includes abstract.
Current concrete specifications used in mix design are mainly of the prescriptive type, i.e.recipe-based specifications that prescribe limiting values for certain mix design parameters such as minimum binder content, maximum water/binder (w/b) ratio and minimum compressive strength class. This has numerous economical, technical and environmental disadvantages and is one of the driving factors behind the development and promotion of performance-based specifications. These have the potential to lead to alternative methods of mix design to improve concrete structural performance. In South Africa, the use of the Durability Index Approach in performance-based specifications has grown increasingly. Durability can be thought of as a materials concept for a structure in a given environment for the duration of its design life. As such, it can only be accurately described by considering it as a function of numerous intrinsic and extrinsic interrelated factors. Despite this, a dominant assumption in the industry is that concrete durability is directly proportional to its binder content and compressive strength, largely due to the misinterpretation of prescriptive specifications in depicting factors like binder content as the governing parameter of durability. This results in uneconomical and often non-durable concretes due to implications of high cement contents, such as high costs (cement is the most expensive constituent of concrete), high shrinkage, thermal effects and alkali-silica reactions. This thesis presents a study on the influence of parameters of mix design, such as w/b ratio, binder content, binder type and curing regime, as well as compressive strength, on the durability of concrete as expressed by the Durability Index Approach. The objective of the investigation was to identify the issues behind specifications of minimum binder contents, as well as identify relationships between mix design parameters, compressive strength and durability indices. This was done by obtaining findings which would serve as a basis to potentially bring about sensible and justifiable changes to specifications. This could in turn lead to more durability-oriented mix design strategies. In order to verify whether prescriptive specifications such as minimum binder contents are justifiable, various studies in literature were reviewed on the subject. In the literature review, it was identified that certain relationships exist between aspects of concrete durability and various parameters, among which are binder content, w/b ratio and compressive strength. It was found that the nature of these relationships cannot be generalised as each relationship needs to take into consideration a variety of additional influencing factors. One example is that the influence of increasing binder content on durability indicators is often detrimental and can seldom be associated with beneficial effects. This is because there are other factors such as increasing paste volume that need to be considered.

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Martín, Severiano Juan Carlos. "IEEE 802.11b MAC layer's influence on VoIP quality parameters : Measurements and Analysis." Thesis, KTH, Mikroelektronik och informationsteknik, IMIT, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92577.

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Real-time voice measurements were performed to assess whether there are significant problems with 802.11b wireless networks regarding real-time voice communication. We present an analysis of how the 802.11b MAC protocol and diverse environmental conditions affect the quality of real-time voice in terms of loss, delay, and jitter. We also reveal practical issues of wireless monitoring with passive sniffers for this type of analysis. The results obtained in our measurements show that in the majority of the experiments the quality was good, but under some circumstances the requirements for an acceptable voice communication were not met.
Realtidsröstmätningar gjordes för att testa om det finns problem med 802.11b trådlösa nätverk beträffande realtidsröstkommunikation. En analys presenteras av hur 802.11b MACs protokoll och olika tillstånd i omgivningen påverkar kvaliteten på realtidsrösten i form av förluster, fördröjningar och jitter. Även praktiska angelägenheter om trådlös övervakning med passiva sniffers visas. De erhållna resultaten visar att i en majoritet av fallen var kvaliteten acceptabel, men under vissa förhållanden blev inte kraven för röstkommunikation uppfyllda.

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Tolson, Jennifer. "Influence of direction on stepping parameters and postural stability in individuals with chronic the influence of walking velocity /." Click here to access thesis, 2009. http://www.georgiasouthern.edu/etd/archive/spring2009/jennifer_m_tolson/tolson_jennifer_m_200901_ms.pdf.

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Thesis (Ed.D.)--Georgia Southern University, 2009.
"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by Thomas Buckley. ETD. Includes bibliographical references (p. 27-30) and appendices.

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Goswami, Ishan. "Influence of geometric and flow variations on coronary diagnostic parameters: An in-vitro study." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367937429.

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Eriksson, Anna-Frida. "An Empirical Investigation of the Influence of Context Parameters on Everyday Planning Activities." Thesis, Linköping University, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4300.

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The purpose of the study is to explore the context, from the users’ perspective, in order to find relevant context parameters that can be useful in the development of the future context-aware technology. The goal is to find some of the context parameters relevant to the situated activity and investigate to what extent and in which way they influence the user in everyday planning activities.

The method used in the study was based on scenario descriptions. A total of 41 participants reported how they would have acted in the different situations and they also rated how important they believed the different context factors were in the situations. Analyses were made to reveal relationships between context factors and service properties used by the participants in the scenarios.

In the study several interesting relationships between context factors and the use of services were discovered. The level of urgency was in several situations considered to be important, and it was also found to have an impact on how the participants chose to communicate. The cost was introduced by the participants during the study. It seemed to be important; however, in situations with high urgency it became less important. The study revealed a potential relationship between the risk of disturbing the people in the vicinity and the effort to communicate quietly. Another interesting finding was the relationship between privacy and the choice of modality when communicating: voice-based services were avoided. Further, the importance of privacy and disturbance also appeared to have greater influence in non-anonymous situations than in anonymous.

Syftet med studien är att undersöka kontexten, utifrån användarens perspektiv, för att kunna hitta relevanta kontextfaktorer som kan vara användbara i utvecklingen av kontextmedveten teknologi. Målet är att finna kontextfaktorer som är relevanta för den pågående aktiviteten och undersöka i vilken utsträckning och på vilka sätt dessa faktorer påverkar användaren i de dagliga planeringsaktiviteterna.

Metoden som användes i studien baserades på scenariobeskrivningar. 41 stycken försöksdeltagare fick beskriva hur de skulle ha handlat i de olika situationerna och de fick också skatta hur viktiga de olika kontextfaktorerena var i situationerna. Analyser genomfördes för att finna samband mellan kontextfaktorer och egenskaper hos de tjänster som försöksdeltagarna använde sig av i scenarierna.

I studien upptäcktes en rad intressanta relationer mellan kontextfaktorer och användningen av tjänster. Exempelvis ansågs nivån av brådska vara betydelsefull i flera situationer och den verkade också ha inverkan på hur försöksdeltagarna valde att kommunicera. Försöksdeltagarna introducerade under studien kontextfaktorn kostnad. Kostnaden påverkade valet av tjänster men blev mindre betydande i situationer med stor brådska. Studien visade också på potentiella samband mellan risken att störa människor i sin omgivning och viljan att kommunicera tyst. En annan intressant upptäckt var sambandet mellan avskildhet och kommunikationssätt: röstbaserade tjänster undveks när andra människor fanns i närheten. Dessutom verkade det som om det var viktigare att värna om sin avskildhet och att inte störa andra i ickeanonyma situationer än i situationer där man var helt anonym.

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Abdulrahman, Ahmed Abdulhamid. "The influence of water content on the rock cutting parameters of six rocks." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310034.

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Weirich, Melanie. "The influence of Nature and Nurture on speaker-specific parameters in twins speech." Doctoral thesis, Humboldt-Universität zu Berlin, Philosophische Fakultät II, 2012. http://dx.doi.org/10.18452/16453.

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Die Dissertation thematisiert sprecherspezifische Variabilität bei ein- und zweieiigen Zwillingen hinsichtlich Artikulation, Akustik und Perzeption. Die zentrale Fragestellung ist, ob sprecherspezifische Charakteristika auf physiologisch-biologischen Differenzen der Sprecher beruhen (BIOLOGIE), oder sich auf gelernte, umweltabhängige Unterschiede zurückführen lassen (UMWELT). Artikulatorische und akustische Daten wurden von 4 eineiigen Zwillingspaaren (EZ, 100% genetische Übereinstimmung) und 3 zweieiigen Zwillingspaaren (ZZ, 50% genetische Übereinstimmung) analysiert. Zusätzlich wurde ein Perzeptionstest zur auditiven Ähnlichkeit der Zwillinge durchgeführt. Auf einen großen Einfluss des Faktors BIOLOGIE lässt sich schließen, wenn sich EZ ähnlicher sind als ZZ. Sind sich aber ZZ genauso ähnlich wie EZ, zeigt sich die Wichtigkeit der gleichen Lernumgebung (UMWELT). Die Ergebnisse weisen auf einen großen Einfluss des Faktors UMWELT und stützen die Hypothese, dass sprachliche Ziele gelernt sind und sich am auditiven Feedback orientieren. Darüber hinaus wurden drei Faktoren gefunden, die den Einfluss der BIOLOGIE intensivieren: a) Lautklasse, b) Wortakzent und c) Koartikulation. Plosive und Sibilanten sind aufgrund des stärker ausgeprägten linguo-palatalen Kontaktes mehr durch die individuelle Physiologie beeinflusst als Vokale. Außerdem wurde ein größerer Effekt des Faktors BIOLOGIE in unbetonten als in betonten Silben gefunden. Zusätzlich stellten sich koartikulatorische Prozesse als wichtig heraus: dynamische Parameter – artikulatorische Gesten und akustische Transitionen – sind stärker durch die Physiologie beeinflusst als statische Parameter – artikulatorische Ziele und stabile akustische Regionen. Sowohl der Faktor BIOLOGIE als auch der Faktor UMWELT sind einflussreiche Größen hinsichtlich sprecherspezifischer Variabilität. Welcher der beiden Faktoren die übergeordnete Rolle übernimmt, hängt von den spezifischen Charakteristika des untersuchten Parameters ab.
This dissertation examines inter-speaker variability in monozygotic (MZ) and dizygotic (DZ) twin pairs in regard to articulation, acoustics and perception. The aim of the study is to evaluate whether speaker-specific variability reflects physiological differences between speakers (NATURE) or bases on learned variation due to social environmental influences (NURTURE). Articulatory and acoustic data was analyzed from 4 MZ twin pairs (100% identical genes) and 3 DZ twin pairs (50 % identical genes). Additionally, a perception experiment was carried out to explore the perceived auditory similarity. The effect of NATURE should have a larger impact than the effect of NURTURE, if a parameter differs more in DZ than in MZ twin pairs. If MZ and DZ twins show the same amount of inter-speaker variability, NURTURE seems to be crucial. Results point to the importance of NURTURE and shared social environment. Nevertheless, three factors were found that intensify the effect of NATURE: a) phoneme class, b) lexical stress, and c) degree of coarticulation. Somatosensory feedback plays a larger role for consonants than for vowels, and thus individual physiology was found to shape articulation more in sibilants and stops than in vowels. Additionally, a stronger impact of NATURE was found in parameters that are auditorily less salient: unstressed syllables were more similar in MZ than in DZ twins, while for stressed syllables this was not the case. Moreover, coarticulation turned out to be essential: dynamic parameters – articulatory gestures and acoustic transitions – were more influenced by physiological constraints (NATURE) than static parameters – articulatory targets and stable acoustic regions. Thus, both NATURE and NURTURE are crucial influencing factors in speaker-specific variability. However, the relative importance of the two factors is highly dependent on the specific characteristics of the investigated parameter.

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Okonji, Osaretin Christabel. "Microbiological parameters that influence the treatment outcomes of monodrug and multidrug-resistant tuberculosis." University of the Western Cape, 2017. http://hdl.handle.net/11394/6148.

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Magister Pharmaceuticae - Mpharm
Previous studies have reported microbiological parameters such as HIV infection, resistance to anti-TB drugs such as fluoroquinolones, resistance to previous treatment with anti-TB drugsand extrapulmonary TB, causing poor treatment outcomes in patients with monodrug and multidrugresistant tuberculosis. However, little is known about the time to sputum culture conversion in HIV-positive patients infected with monodrug and multidrug-resistant tuberculosis in South Africa, and currently there is no information on the effects of inappropriate (i.e. low and high) anti-tuberculosis drug-dose on the time to sputum culture conversion in monodrug and multidrug-resistant TB patients. The aim of the study was to investigate whether or not there is a difference between the time to sputum culture conversion in drug-resistant tuberculosis patients with HIV, and those without HIV infection. It also aimed to find out whether inappropriate (i.e. low and high) anti-tuberculosis drug dose could affect the time to sputum culture conversion in drug-resistant TB patients. In addition, the influence of HIV infection (CD4 count and viral load), drug resistance type, impact of antiretroviral duration before TB treatment, the replacement of ofloxacin by moxifloxacin and DR-TB localization were assessed on drugresistant TB treatment outcomes.

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Karimi, Neghlani Paria. "Electron beam melting of Alloy 718 : Influence of process parameters on the microstructure." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-13140.

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Additive manufacturing (AM) is the name given to the technology of building 3D parts by adding layer-by-layer of materials, including metals, plastics, concrete, etc. Of the different types of AM techniques, electron beam melting (EBM), as a powder bed fusion technology, has been used in this study. EBM is used to build parts by melting metallic powders by using a highly intense electron beam as the energy source. Compared to a conventional process, EBM offers enhanced efficiency for the production of customized and specific parts in aerospace, space, and medical fields. In addition, the EBM process is used to produce complex parts for which other technologies would be either expensive or difficult to apply. This thesis has been divided into three sections, starting from a wider window and proceeding to a smaller one. The first section reveals how the position-related parameters (distance between samples, height from build plate, and sample location on build plate) can affect the microstructural characteristics. It has been found that the gap between the samples and the height from the build plate can have significant effects on the defect content and niobium-rich phase fraction. In the second section, through a deeper investigation, the behavior of Alloy 718 during the EBM process as a function of different geometry-related parameters is examined by building single tracks adjacent to each other (track-by-track) andsingle-wall samples (single tracks on top of each other). In this section, the main focus is to understand the effect of successive thermal cycling on microstructural evolution. In the final section, the correlations between the main machine-related parameters (scanning speed, beam current, and focus offset) and the geometrical (melt pool width, track height, re-melted depth, and contact angle) and microstructural (grain structure, niobium-rich phase fraction, and primary dendrite arm spacing) characteristics of a single track of Alloy 718 have been investigated. It has been found that the most influential machine-related parameters are scanning speed and beam current, which have significant effects on the geometry and the microstructure of the single-melted tracks.

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Zadonina, Ekaterina. "Strong ground motion simulations and assessment of influence of model parameters on waveforms." Master's thesis, Universidade de Évora, 2010. http://hdl.handle.net/10174/21222.

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A modelação de movimentos sísmicos intensos em campo próximo é um importante instrumento da sismologia moderna, usado nos estudos de sismologia e risco sísmico. Existem várias abordagens para calcular os movimentos do solo produzido por fontes sísmicas finitas. Neste trabalho utilizámos um algoritmo de diferenças finitas, desenvolvido para estruturas 3D e modelos cinemáticos de fonte, para calcular os movimentos da Terra em campo próximo produzidos por um evento real. Os sismogramas sintéticos e as correspondentes formas de onda registadas são quantitativamente comparadas para justificar o modelo usado. Foram também ensaiados o efeito das variações de alguns parâmetros que caracterizam a fonte e a estrutura (velocidade de ruptura, dimensão e geometria, modelo de velocidade), sobre as formas de onda. Os resultados obtidos mostraram, em geral, boa concordância entre os dados observados e sintéticos e revelam a diferente capacidade que os parâmetros envolvidos têm para influenciar as formas de onda obtidas. __ Summary: Modeling near-field ground motion is an important and helpful tool of modem seismology. It helps in studies of seismic events and mitigation of seismic hazards. Several approaches are widely used to obtain synthetic ground motion for a finite earthquake source. ln our work we use a finite-difference algorithm, developed for 3D structures and kinematic source models, to compute near-field ground motions from a real moderate event with pre-existing slip distribution model. Lately, synthetic seismograms are quantitatively compared with observed waveforms from near-field seismic stations on order to justify created model. Moreover, we independently changed several source parameters (rupture velocity, source dimension and geometry), and structure (velocity model) to evaluate their influence on the waveforms. Here we also applied quantitative comparison of seismograms. Obtained results showed generally good agreement in magnitudes of motion between observed and synthetic data, and revealed effect of different model parameters on the waveforms.

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Elhilaly, Mohamed A. "Influence of Ultra-high Temperature Process Parameters on Age Gelation of Mille Concentrate." DigitalCommons@USU, 1994. https://digitalcommons.usu.edu/etd/5412.

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The purpose of this research was to investigate the effect of ultra-high temperature process parameters on age gelation of milk concentrate. Skim milk was concentrated to 2X (volume reduction) using reverse osmosis. The milk concentrate was preheated at 75 or 90°C for 20 or 50 s and UHT-processed at 138 or 145°C for 4 or 16 s. Sterilizing methods used were direct steam injection and indirect plate heat exchanger. The samples were aseptically collected in presterilized plastic containers and stored at 15 or 35°C. At 15°C storage temperature, the steam-injected samples gelled in 5 months when 4 s UHT time was used. When UHT time was increased to 16 s, the samples gelled in 6 months. Of the samples that were UHT processed by indirect plate heat exchanger for 4 s and stored at 15°C, all gelled after 7 months. When UHT time was increased to 16 s, all the 138°C samples gelled after 7 months as did the samples that were preheated for 50 s and UHT-processed at 138°C. The samples preheated at 75°C for 50 sand UHT-processed at 145°C gelled after 8 months, whereas at 90°C preheat temperature the samples gelled after 9 months. The samples stored at 35°C did not gel but showed different sedimentation levels. The sediment depth in the container was always greater for the steam-injected samples. The samples that received higher heat treatments by the two processing methods had a higher sedimentation depth. The pH decreased during storage and the extent of reduction was higher at 35°C storage temperature . Maillard browning occurred at both storage temperatures. Browning was greater in samples stored at 35°C and processed by indirect plate heat exchanger.

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Bapat, Amey Vivek. "Influence of Bridge Parameters on Finite Element Modeling of Slab on Girder Bridges." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/36105.

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The present study is part of the Long Term Bridge Performance Program (LTBP) funded by the Federal Highway Administration. The objectives of this program are to create a comprehensive database of quantitative information of the long-term performance of selected pilot bridges and to develop a methodology to assess bridge performance. Finite element (FE) modeling of the pilot bridges is an intrinsic part of the LTBP program and is intended to not only assist with instrumentation decisions, but also to provide further insight into the behavior of these bridges, which cannot be achieved solely from field testing of the bridges. This thesis provides a comprehensive study of a plethora of issues associated with the development of reliable and accurate FE models of bridges. The first objective of this investigation was to develop reliable finite element models with a variety of levels of refinement and to study the effect of the inclusion of various bridge parameters in the model, such as bridge skew, degree of composite action, thermal gradient and level of support restraint, on the response of bridges. First, the suitability of different modeling techniques and of elements used to model the primary bridge components was assessed using simple models for which analytical solutions are readily available. From these studies, it was concluded that shell elements are adequate to model the bridge deck, and beam and shell elements are both satisfactory to model the bridge girders. From the dynamic analyses of theWildcat Creek River Bridge and the Colquitz River Bridge, flexural modes of vibration were found to be highly sensitive to support restraints and to how the guardrails were modeled and less sensitive to the inclusion of bracing and thermal gradients in the model. The finite element models using extreme boundary conditions were successful in bracketing the field response. The factors identified from these analyses were considered in the analysis of the Virginia pilot bridge. Different support restraints, and the inclusion of skew and level of composite action in the model had noticeable impact on both the static and dynamic responses of the bridge. The results from these analyses were used to assist with instrumentation decisions prior to field-testing. The developed model will also be used to help researchers further understand the bridgeâ s behavior and to help explain a variety of phenomena observed in the field.
Master of Science

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Dissertations / Theses on the topic 'The influence of parameters'

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