Dissertations / Theses: 'Pressure arch'

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Lee, Dong Gil. "Relationship between arch height and midfoot joint pressures during gait." Cleveland, Ohio : Cleveland State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1227563948.

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Thesis (D. Eng.)--Cleveland State University, 2008.
Abstract. Title from PDF t.p. (viewed on Feb. 2, 2009). Includes bibliographical references. Available online via the OhioLINK ETD Center. Also available in print.

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Housley, Jeffrey A. "Stability of transverse expansion in the mandibular dental arch." Oklahoma City : [s.n.], 2002. http://library.ouhsc.edu/epub/theses/Housley-Jeffrey-A.pdf.

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Figueiredo, Alexandre. "Relação entre a morfologia do arco plantar longitudinal medial e a pressão plantar em indivíduos saudáveis." Bachelor's thesis, [s.n.], 2019. http://hdl.handle.net/10284/8792.

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Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciado em Fisioterapia
Objetivo: Comparar a pressão plantar e a velocidade do deslocamento do centro de pressão (CdP) entre pés normais, cavos e planos em indivíduos adultos saudáveis. Metodologia: foi realizado um estudo observacional, com 26 indivíduos saudáveis, classificados com pés normais (n=22), pés cavos (n=6) e pés planos (n=24) baseado no Foot Posture Index – 6. Os indivíduos caminharam normalmente ao longo de um espaço de 10 metros, enquanto usavam um sistema de análise de pressão plantar F-scan (Tekscan). Utilizaram-se 5 áreas que incluíram o retropé, médiopé, antepé, dedos e pé total. A pressão plantar máxima (PPmáx) e o integral pressão-tempo (IPT) e o centro de pressão (CdP) foram calculados para cada área. Resultados: não foram encontradas alterações significativas (p> 0,05) entre as variáveis PPmáx e o IPT com o arco plantar, no entanto foram encontradas alterações significativas para a velocidade do CdP com o arco plantar (p <0,05). Conclusão: este estudo confirma que o arco plantar longitudinal medial influencia algumas variáveis de pressão plantar, nomeadamente a velocidade do CdP.
Objective: To compare plantar pressure and the velocity of center of pressure (COP) displacement between normal, cavus and planus foot in healthy adult subjects. Methods: An observational study was performed with 26 healthy individuals classified as normal feet (n = 22), cavus feet (n = 6) and planus feet (n = 24) based in the Foot Posture Index - 6. Individuals walked normally over a 10 meters span, while using an F- scan (Tekscan) plantar pressure analysis system. Five areas were used that included the hindfoot, midfoot, forefoot, toes and total foot. The peak pressure (PP), integral pressure-time (PTI), center of pressure (COP) were calculated for each area. Results: no significant changes (p> 0.05) were found between the variables peak pressure (PP), total pressure-time integral (PTI) with the plantar arch, but significant changes were found for the velocity of center of pressure (COP) with the plantar arch (p <0.05). Conclusion: this study confirms that the medial longitudinal plantar arch influences some plantar pressure variables, namely the velocity of COP.
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Palhano, Rudnei. "Análise biomecânica do arco plantar longitudinal medial durante a fase de apoio na marcha." Universidade do Estado de Santa Catarina, 2008. http://tede.udesc.br/handle/handle/398.

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Made available in DSpace on 2016-12-06T17:07:16Z (GMT). No. of bitstreams: 1 RUDNEI PALHANO.pdf: 3683877 bytes, checksum: fe25b167aa6def43f3bead628f1850d4 (MD5) Previous issue date: 2008-04-25
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The aim of this correlational study was to analyze the plantar medial longitudinal arch during the stance phase of the gait. Thirty-two subjects of both genders (mean age 25,78±6,75 years) from Vale dos Sinos RS have participated of the research. The specific objectives was to describe the behavior of the plantar medial longitudinal arch during the gait in the initial contact and stance phase; identify the foot s angle with the surface in the initial contact; correlate the medial longitudinal plantar arch with the Ankle s angle during the contact phase; correlate the anthropometry variables with the dynamic behavior of the medial longitudinal plantar arch; correlate the plantar pressure distribution (peak pressure, plantar pressure mean, contact time and mean area) with the dynamic behavior of the kinetics and kinematics variables of the medial longitudinal plantar arch during the stance phase and relate the kinetics and kinematics variables with kinds of medial longitudinal plantar arch. The kinematics data has been acquired by the Spica Technology Corporation video system and for kinetic data was used the Novel Emed-XR system with a sampling rate of 100 Hz and the 3D Scanner INFOOT. Subjects were separate into three groups by the Cavanagh s arch index: Cavus foot; normal foot e planus foot. The variables analyzed were: medial longitudinal plantar arch angle in seated position, initial contact and stance phase, angle of the ankle in seated position and stance phase, plantar pressure of peak, mean plantar pressure, contact area, contact time and mean force. The Kolmogorov-Smirnov test has been applied for the statistical analysis to verify the normality of the data. The ANOVA One-Way test has been used to compare means intra-groups and to verify where were the differences was used the Scheffé`s Post Hoc test. Pearson test has been applied to verify the correlation. The level of significance adopted was p ≤ 0.05. There were no differences statistically significant when inter-groups kinematics and anthropometrics variables had been compared. Only in some regions of the plantar surface has shown differences statistically significant when the kinetics variables were compared inter-group. Analyzing the correlations between the dynamic arch index with kinematics variables, only the medial longitudinal plantar arch angle has shown a moderate correlation statistically significant, while others correlations had low relations.
O objetivo deste estudo correlacional foi analisar o Arco Plantar Longitudinal Medial durante a fase de apoio da Marcha. Com objetivos específicos: descrever o comportamento do Arco Plantar Longitudinal Medial durante a marcha nos períodos do Contato Inicial e Apoio Simples; Identificar o Ângulo do pé com a superfície no Contato Inicial; Correlacionar o Ângulo do Arco Plantar Longitudinal Medial com o Ângulo do Tornozelo durante a Fase de Contato; Correlacionar as variáveis antropométricas com o comportamento dinâmico do Arco Plantar Longitudinal Medial; Correlacionar as variáveis da Distribuição de Pressão Plantar (Pico de Pressão Plantar, Pressão Plantar Média, Tempo de contato e Área media) com o comportamento dinâmico das variáveis cinemáticas e cinéticas do Arco Plantar Longitudinal Medial durante a o apoio simples;Verificar diferenças nas variáveis cinemáticas e cinéticas relacionando com os diferentes tipos de Arco Plantar Longitudinal Medial dinamicamente. Participaram do estudo 32 sujeitos da região do Vale dos Sinos RS, ambos os sexos, idade entre 19 e 46 anos (25,78±6,75 anos). Utilizaram-se como instrumentos o Sistema de cinemetria da Spica Technology , Sistema cinético da Novel Emed e o Scanner 3D INFOOT. Os sujeitos foram classificados em três grupos através do Índice do Arco Plantar: Pés Cavos (PC); Pés Normais (PN) e Pés Planos (PP). As variáveis analisadas foram: Ângulo do Arco Plantar Longitudinal Média, na posição sentada, contato inicial e no apoio simples; Ângulo do Tornozelo, na posição sentada e apoio simples; Pico de Pressão Plantar; Pressão Plantar Média; Área de Contato; Tempo de Contato e Força Média. Na análise estatística foi aplicado o teste de Kolmogorov-Smirnov para verificar a normalidade nos dados. Na comparação das médias intra-grupos foi aplicado ANOVA One-Way e para verificar onde as diferenças encontravam foi utilizado o teste de Post hoc de Scheffé. Para verificar as correlações foi aplicado Pearson. O nível de significância adotado foi de p≤ 0,05. Na comparação inter-grupos para as variáveis cinemáticas e antropométricas, não apresentaram diferenças estatisticamente significativas. Apenas na comparação inter-grupos das variáveis cinéticas, em algumas regiões da superfície plantar apresentaram diferenças estatisticamente significativas. Ao analisar as correlações entre o Índice do Arco Plantar dinâmico com as variáveis cinemáticas, somente o ângulo do Arco Plantar longitudinal medial apresentou correlação moderada estatisticamente significativa, as demais variáveis cinemáticas apresentaram correlações baixas.

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Ramqvist, Anders, and Martin Länsman. "Computational fluid dynamics study of the spillway and plunge pool at Baihetan hydropower station : Numerical validation of the pressure distribution on the floor of an inverted-arch plunge pool." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216968.

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Pokela, M. (Matti). "Predictors of brain injury after experimental hypothermic circulatory arrest:an experimental study using a chronic porcine model." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:951427105X.

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Abstract There is a lack of reliable methods of evaluation of brain ischemic injury in patients undergoing cardiac surgery. The present study was, therefore, planned to evaluate whether serum S100β protein (I), brain cortical microdialysis (II), intracranial pressure (III) and electroencephalography (EEG) (IV) are predictive of postoperative death and brain ischemic injury in an experimental surviving porcine model of hypothermic circulatory arrest (HCA). One hundred and twenty eight (128) female, juvenile (8 to 10 weeks of age) pigs of native stock, weighing 21.0 to 38.2 kg, underwent cardio-pulmonary bypass prior to, and following, a 75-minute period of HCA at a brain temperature of 18°C. During the operation, hemodynamic, electrocardiograph and temperature monitoring was performed continuously. Furthermore, metabolic parameters were monitored at baseline, end of cooling, at intervals of two, four and eight hours after HCA and before extubation. Electroencephalographic recording was performed in all animals, serum S100β protein measurement in 18 animals, cortical microdialysis in 109 animals, and intracranial pressure monitoring in 58 animals. After the operation, assessment of behavior was made on a daily basis until death or elective sacrifice on the seventh postoperative day. All four studies showed that these parameters were predictive of postoperative outcome. Animals with severe histopathological injury had higher serum S100β protein levels at every time interval after HCA. Analysis of cortical brain microdialysis showed that the lactate/glucose ratio was significantly lower and the brain glucose concentration significantly higher among survivors during the early postoperative hours. Intracranial pressure increased significantly after 75 minutes of HCA, and this was associated with a significantly increased risk of postoperative death and brain infarction. A slower recovery of EEG burst percentage after HCA was significantly associated with the development of severe cerebral cortex, brain stem and cerebellum ischemic injury. In conclusion, serum S100β protein proved to be a reliable marker of brain ischemic injury as assessed on histopathological examination. Cerebral microdialysis is a useful method of cerebral monitoring during experimental HCA. Low brain glucose concentrations and high brain lactate/ glucose ratios after HCA are strong predictors of postoperative death. Increased intracranial pressure severely affected the postoperative outcome and may be a potential target for treatment. EEG burst percentage as a sum effect of anesthetic agent and ischemic brain damage is a useful tool for early prediction of severe brain damage after HCA. Among these monitoring methods, brain cortical microdialysis seems to be the most powerful one in predicting brain injury after experimental hypothermic circulatory arrest.

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Gaudric, Julien. "Morphométrie des anévrismes de l’aorte thoracique : de l’anatomie scanographique à la modélisation numérique." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS574.

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Rationnel : L’étude de l’anatomie de la crosse aortique a évolué pour optimiser le traitement des anévrismes par endoprothèse.Objectifs : I : caractériser les modifications morphométriques de la crosse induites par un anévrisme. II : évaluer la faisabilité des dispositifs endovasculaires actuels pour traiter les anévrismes de la crosse. III : créer un outil automatisé de mesure pour évaluer les angulations induites par ces déformations. IV : valider un modèle numérique de simulation 0D de la mécanique vasculaire en le confrontant à des données in vivo.Résultats : I : nous avons montré sur une étude scannographique que les anévrismes thoraciques s’accompagnaient d’un étirement bi directionnel de la paroi et d’une rotation de la crosse antérieure ou postérieure selon la localisation de l’anévrisme. II : parmi 56 malades opérés chirurgicalement d’anévrismes de la crosse, l’étude rétrospective de leur scanner montrait qu’aucun n’avait les critères anatomiques pour permettre une endoprothèse branchée. III : nous avons créé un logiciel de calcul automatisé des points de courbure maximale de l’aorte à partir d’une analyse continue du rayon de courbure de la ligne centrale. Sa pertinence a été validée par sa concordance avec la détermination visuelle des points. IV : nous avons confronté la déformation de l’onde de pression artérielle après clampage et déclampage de l’aorte chez 11 patients avec une bonne corrélation et accord entre un modèle numérique et des enregistrements continus intravasculaires. Conclusion : Les progrès dans l’analyse de la conformation de l’aorte et de la mécanique vasculaire sont nécessaires à l’adaptation de nouveaux substituts endovasculaires
Rational: Research on the anatomy of the aortic arch has been fueled by the need of a comprehensive analysis of this structure in the setting of endovascular repair. Aneurysmal disease causes distortions in areas where the implantation of stent grafts undergo major stress. Objectives: I: To characterize the morphometric modifications of the aortic arch induced by a thoracic aneurysm. II: To evaluate the feasibility of current endovascular devices in treating aortic arch aneurysms. III: To create an automated measurement tool for assessing the angulations induced by these deformations. IV: To validate a 0D numerical simulation model of vascular mechanics by comparing its predictions with in vivo data.Results: I: In a study of 78 CT scan, thoracic aneurysms were associated with bi-directional wall stretching and anterior or posterior rotation according to the aneurysm’s location. II: A retrospective study of the CT scans of 56 patients who underwent aortic arch aneurysm surgical repair showed that none of these patients had the anatomical criteria for a stent graft implantation. III: An automated software for calculating the aortic angulations from a continuous analysis of the curvature radius of the central line was developed and validated against the visual assessment of points. IV: Changes in the morphology of blood pressure waves after aortic clamping and unclamping were studied in 11 patients with a good correlation and agreement between the numerical model and continuous intravascular measurements. Conclusion: Advances in the analysis of aortic geometry and the simulation of vascular mechanics are necessary for the adaptation of new endovascular devices

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Reed, Lloyd Fisher. "An investigation of foot and ankle problems experienced by nurses." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/35779/1/Lloyd_Reed_Thesis.pdf.

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Relatively little information has been reported about foot and ankle problems experienced by nurses, despite anecdotal evidence which suggests they are common ailments. The purpose of this study was to improve knowledge about the prevalence of foot and ankle musculoskeletal disorders (MSDs) and to explore relationships between these MSDs and proposed risk factors. A review of the literature relating to work-related MSDs, MSDs in nursing, foot and lower-limb MSDs, screening for work-related MSDs, foot discomfort, footwear and the prevalence of foot problems in the community was undertaken. Based on the review, theoretical risk factors were proposed that pertained to the individual characteristics of the nurses, their work activity or their work environment. Three studies were then undertaken. A cross-sectional survey of 304 nurses, working in a large tertiary paediatric hospital, established the prevalence of foot and ankle MSDs. The survey collected information about self-reported risk factors of interest. The second study involved the clinical examination of a subgroup of 40 nurses, to examine changes in body discomfort, foot discomfort and postural sway over the course of a single work shift. Objective measurements of additional risk factors, such as individual foot posture (arch index) and the hardness of shoe midsoles, were performed. A final study was used to confirm the test-retest reliability of important aspects of the survey and key clinical measurements. Foot and ankle problems were the most common MSDs experienced by nurses in the preceding seven days (42.7% of nurses). They were the second most common MSDs to cause disability in the last 12 months (17.4% of nurses), and the third most common MSDs experienced by nurses in the last 12 months (54% of nurses). Substantial foot discomfort (Visual Analogue Scale (VAS) score of 50mm or more) was experienced by 48.5% of nurses at sometime in the last 12 months. Individual risk factors, such as obesity and the number of self-reported foot conditions (e.g., callouses, curled toes, flat feet) were strongly associated with the likelihood of experiencing foot problems in the last seven days or during the last 12 months. These risk factors showed consistent associations with disabling foot conditions and substantial foot discomfort. Some of these associations were dependent upon work-related risk factors, such as the location within the hospital and the average hours worked per week. Working in the intensive care unit was associated with higher odds of experiencing foot problems within the last seven days, foot problems in the last 12 months and foot problems that impaired activity in the last 12 months. Changes in foot discomfort experienced within a day, showed large individual variability. Fifteen of the forty nurses experienced moderate/substantial foot discomfort at the end of their shift (VAS 25+mm). Analysis of the association between risk factors and moderate/substantial foot discomfort revealed that foot discomfort was less likely for nurses who were older, had greater BMI or had lower foot arches, as indicated by higher arch index scores. The nurses’ postural sway decreased over the course of the work shift, suggesting improved body balance by the end of the day. These findings were unexpected. Further clinical studies examining individual nurses on several work shifts are needed to confirm these results, particularly due to the small sample size and the single measurement occasion. There are more than 280,000 nurses registered to practice in Australia. The nursing workforce is ageing and the prevalence of foot problems will increase. If the prevalence estimates from this study are extrapolated to the profession generally, more than 70,000 hospital nurses have experienced substantial foot discomfort and 25-30,000 hospital nurses have been limited in their activity due to foot problems during the last 12 months. Nurses with underlying foot conditions were more likely to report having foot problems at work. Strategies to prevent or manage foot conditions exist and they should be disseminated to nurses. Obesity is a significant risk factor for foot and ankle MSDs and these nurses may need particular assistance to manage foot problems. The risk of foot problems for particular groups of nurses, e.g. obese nurses, may vary depending upon the location within the hospital. Further research is needed to confirm the findings of this study. Similar studies should be conducted in other occupational groups that require workers to stand for prolonged periods.

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Markgren, Jakob. "CFD Modelling of Pressure-control Devices in Substations." Thesis, Umeå universitet, Institutionen för fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96455.

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Tait, Robert Niall. "Ignition of arc discharges at high pressures." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28523.

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This report describes attempts to discover a method for starting a water walled argon arc at high pressure. It is demonstrated that addition of small amounts of acetylene to the argon causes a very small reduction of breakdown voltage at pressures of about 3 atmospheres. Droplets of distilled water and of KC1 solution are shown to effectively increase the breakdown potential of a gas. A calculation of static fields before arc ignition is presented, and alternative starting circuit tests are done. Parallel starting pulse injection is found inferior to the normally used series injection. An auxiliary discharge is found to aid starting slightly, and a drastic decrease in the breakdown potential due to removal of the water wall is discovered.
Science, Faculty of
Physics and Astronomy, Department of
Graduate

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Zhan, Yiyi. "PC-based visual simulation of high pressure arc plasma." Thesis, University of Liverpool, 2011. http://livrepository.liverpool.ac.uk/3433/.

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Göktuğ, Gökhan. "On the effect of environmental pressure on gas tungsten arc welding process." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/39620.

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Meier, Rudolf. "Mass-spectroscopic study of the influence of nozzle material on high-pressure SF₆-arcs /." Zürich, 1988. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8570.

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Fanara, C. "A Langmuir multi-probe system for the characterization of atmospheric pressure arc plasmas." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/96.

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The 'high-pressure' atmospheric (TIG) arc plasma is studied by means of a multi-Langmuir probe system. In order to determine the appropriate regime of operation, definitions of the plasma parameters for the description of the argon arc are considered and evaluations are presented. A description of the probe basic techniques is followed by an in-depth discussion of the different regimes of probe operation. The emphasis is put on atmospheric and flowing (arc) regimes. Probe sheath theories are compared and “Nonidealities” like cooling due to plasma-probe motion and probe emission mechanisms are then described. The extensive literature review reveals that the existing probe theories are inappropriate for a use in the TIG arc, because of ‘high’ pressure (atmospheric), broad range of ionization across the arc, flowing conditions, and ultimately, to the uncertainty about onset of Local Thermodynamical Equilibrium. The Langmuir probe system is built to operate in floating and biased conditions. The present work represents the first extensive investigation of electrostatic probes in arcs where the experimental difficulties and the primary observed quantities are presented in great detail. Analysis methodologies are introduced and experimental results are presented towards a unified picture of the resulting arc structure by comparison with data from emission spectroscopy. Results from different measurements are presented and comparison is made with data on TIG arcs present in literature. Probe obtained temperatures are lower than the values obtained from emission spectroscopy and this ‘cooling’ is attributed to electron-ion recombination. However, it is believed that probes can access temperatures regions not attainable by emission spectroscopy. Only axial electric potential and electric field are obtained because of the equipotential-probe requirement. Estimations of the sheath voltage and extension are obtained and a qualitative picture of the ion and electron current densities within the arc is given.

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Gallimore, Scott D. Jr. "Operation of a High-Pressure Uncooled Plasma Torch with Hydrocarbon Feedstocks." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36917.

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The main scope of this project was to determine if a plasma torch could operate on pure hydrocarbon feedstocks and, if so, to catalogue the torch operational characteristics. The future goal of the project is to design a plasma torch for supersonic combustion applications that operates off of the vehicle main fuel supply to simplify onboard fuel systems. Experiments were conducted with argon, methane, ethylene and propylene. Spectrographic tests and tests designed to catalogue current/voltage characteristics, plasma jet phenomena, arc stability dependencies, electrode erosion rate and torch body temperature were performed. Spectrographic analysis of the plasma jet exhaust confirmed the presence of combustion-enhancing radicals for each hydrocarbon gas tested. Also, it was discovered that simple hydrocarbon gases, such as methane, produced smooth torch operation, while even slightly more complex gases, ethylene and propylene, caused unsteady performance. Plasma jet oscillation was found to be related to the voltage waveform of the power supplies, indicating that plasma jet length and oscillation rate could be controlled by changing the input voltage. The plasma torch for this study was proven to have the capability of operating with pure hydrocarbon feedstocks and producing radicals that are known to reduce combustion reaction rate times. The torch was demonstrated to have potential for use in supersonic combustion applications.
Master of Science

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Richardson, I. M. "Properties of the constricted gas tungsten (plasma) welding arc at elevated pressures." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280909.

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Huang, Yi. "CONTROL OF METAL TRANSFER AT GIVEN ARC VARIABLES." UKnowledge, 2011. http://uknowledge.uky.edu/ece_etds/4.

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Gas Metal Arc Welding (GMAW) is one of the most important welding processes in industrial application. To control metal transfer at given variables is a focus in the field of research and development in welding community. In this dissertation, laser enhanced GMAW is proposed and developed by adding a lower power laser onto the droplet to generate an auxiliary detaching force. The electromagnetic force needed to detach droplets, thus the current that determines this force, is reduced. Wire feed speed, arc voltage, and laser intensity were identified as three major parameters that affect the laser enhanced metal transfer process and a systematic series of experiments were designed and conducted to test these parameters. The behaviors of the laser enhanced metal transfer process observed from high speed images were analyzed using the established physics of metal transfer. In all experiments, the laser was found to affect the metal transfer process as an additional detaching force that tended to change a short-circuiting transfer to drop globular or drop spray, reduce the diameter of the droplet detached in drop globular transfer, or decrease the diameter of the droplet such that the transfer changed from drop globular to drop spray. The enhancement of the laser was found to increase as the laser intensity increased. The larger laser intensity tended to help reduce the size of the droplet detached. The arc voltage affected the metal transfer process through changing the current and changing the gap and possible time interval of the droplet development. A larger arc voltage helped reduce the size of the droplet detached through an increased electromagnetic force. Desired heat input and current/arc pressure waveforms may thus be both delivered and controlled by GMAW through laser enhancement. Laser recoil pressure force was estimated based on the difference of gravitational force with and without laser pulse, and the result was with an acceptable accuracy. Good formation of welds and full penetration of thin plate could be obtained using laser enhanced GMAW. A nonlinear model was established to simulate the dynamic metal transfer in laser enhanced GMAW, and the results agree with the experimental one.

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Kim, George E. (George Ea-Hwan). "The effects of low pressure nitrogen on titanium cathode sources in TiN arc ion-plating." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29062.

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The arc ion-plating technique is used in the industrial coating processes where TiN thin films are deposited onto various base materials. The overall objective of this research was to study the effects of low pressure nitrogen introduced into a continuous, titanium vacuum arc. An arc ion-plating system was designed and built to allow for as much flexibility as possible. Permanent magnets were placed behind the cathode surface to confine and rotate the arc.
Changes in cathode, arc and emission properties were noted with respect to vacuum, argon and nitrogen ambients. The introduction of nitrogen, above a critical pressure ($ sim$1 $ times 10 sp{-3}$ Torr), increased arc velocity and decreased crater diameter, erosion rate and ion emission. This occurred when arc rotation was combined with nitrogen introduction. Thermal properties of the cathode during arcing seemed to play an important role in determining the extent of nitrogen-cathode interaction. X-ray photoelectron spectroscopy (XPS) analysis has shown that nitriding occurred within the regions of arcing and was dependent on nitrogen pressure (with all other parameters remaining constant). The most encouraging result found was the complete elimination or macroparticles normally present in the coating/film.

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Wearing, Scott C. "A biomechanical analysis of plantar fasciitis using digital fluoroscopy." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/36791/1/36791_Digitised%20Thesis.pdf.

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Plantar fasciitis is the most common disorder of the foot and is characterised by pain involving the inferomedial aspect of the heel that is exacerbated by activity after periods of non-weightbearing. Despite an abundance of anecdotal evidence indicating that aberrant function of the foot is an aetiological factor in the development of plantar heel pain, there is little scientific evidence linking abnormal arch mechanics with plantar fasciitis. The primary purpose of this thesis was to investigate the biomechanics of plantar fasciitis by evaluating the sagittal plane kinematics and kinetics of the medial longitudinal arch during gait. Specifically, a low-dose motion X-ray technique, known as digital fluoroscopy, was used to evaluate the sagittal plane kinematics of the arch and a capacitance-based pressure plate was used to determine regional vertical ground reaction forces acting on the sole of the foot during gait. Since digital fluoroscopy has not been widely used in gait analysis, the methodological phase of this study concentrated on identifying and quantifying the inherent limitations and potential errors in employing fluoroscopy as a gait analysis technique. In particular, the methodological phase evaluated the potential impact of the physical restrictions of the equipment on gait and the acquisition of gait data, as well as the magnitude of the distortion errors inherent in fluoroscopic images of the medial longitudinal arch. The findings indicate that digital fluoroscopy may be effectively used as a two-dimensional motion analysis technique for the evaluation of movement of the medial longitudinal arch during walking. The methodological studies demonstrate that the structural limitations of modem fluoroscopic systems are unlikely to substantially influence the acquisition of gait data. However, out-ofplane motion of osseous segments of the foot and the temporal response of the imaging system represent the major shortcomings of employing fluoroscopy as a gait analysis tool. Tests conducted on foot models and in vivo indicated that the application of published dist01iion correction procedures provided a method that is highly repeatable, with fluoroscopic image enors constituting less than 5 percent of the movement range. In the experimental phase of this thesis, a digital fluoroscope and a pressure platform were used to evaluate the kinematics and kinetics of the medial longitudinal arch in people with and without plantar fasciitis. While pressure analysis demonstrated that patients with plantar fasciitis make gait adjustments that reduce the level of force beneath the rearfoot and forefoot of the symptomatic foot, fluoroscopy indicated that neither the dynamic shape nor the motion of the medial longitudinal arch differed between subjects with and without heel pain. Consequently, abnonnal arch shape and motion are not associated with the progression of plantar fasciitis. The peak arch angle was, however, positively correlated to the increased fascial thickness that was prototypic of plantar fasciitis. Thus, arch mechanics may play an important secondary role in plantar fasciitis by modifying the severity of heel pain, once present. In addition, increased loading and flexion of the digits was observed in patients with heel pain, suggesting that digital function plays an important, and previously unidentified, protective role in plantar fasciitis by bracing the medial longitudinal arch and thereby reducing the loading in the plantar fascia. The findings also suggest that plantar fasciitis may represent a bilateral process and raise questions regarding the rationale behind current treatments aimed at modifying the mechanics of the medial longitudinal arch in heel pain.

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Cave, W. R. "Investigation of the constricted plasma arc process for hyperbaric welding at pressures 1 to 100bar." Thesis, Cranfield University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360220.

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André, Thibault. "Etude des mécanismes d'entretien et de propagation d'un arc électrique de court-circuit entre câbles endommagés dans les réseaux électriques d'aéronefs." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30050/document.

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Les arcs électriques de défaut se produisant entre deux câbles endommagés peuvent donner lieu à un phénomène appelé " arc tracking ", qui se caractérise par le maintien et la propagation de cet arc le long des câbles, entraînant leur ablation progressive. Dans un réseau aéronautique, un tel défaut peut avoir de graves conséquences lorsqu'il apparaît au sein d'un toron de câbles, d'autant plus qu'il est susceptible de se transférer à une structure avoisinante. Un dispositif expérimental a été développé pour l'étude de ce phénomène. Il est constitué d'une alimentation conçue selon des spécifications propres au domaine aéronautique, permettant de générer un signal continu ou alternatif pendant une durée réglable. Afin de se rapprocher des conditions de vol (pression réduite à haute altitude), les essais sont effectués au sein d'une enceinte fermée, soit à 1 bar, soit à 95 mbar. Trois types de câbles sont testés, un en aluminium et deux en cuivre. En régime continu, ils sont reliés au + et au - de l'alimentation, et à deux phases en régime alternatif. Une plaque en aluminium, représentant la structure de l'avion et connectée au neutre du générateur en régime alternatif, est placée en regard de la partie dénudée des câbles, là où se produit l'arc, permettant un éventuel transfert de l'arc depuis les câbles vers cette plaque. Chaque test s'accompagne de l'acquisition systématique des signaux de courant et de tension, et deux capteurs de flux radiatif sont positionnés autour de l'arc. Une caméra rapide permet la visualisation du comportement de l'arc au cours de l'essai. Enfin, les échantillons de câbles sont pesés avant et après chaque test. Un bilan de puissance est réalisé pour les différentes configurations testées (courant, pression, câbles), afin d'estimer la répartition de la puissance totale entre les électrodes (fusion et vaporisation des câbles, conduction, rayonnement) et la colonne de plasma (rayonnement, conduction, convection). La part transférée aux électrodes est estimée au moyen de la valeur de la chute de tension aux électrodes et du courant. Une partie de cette puissance aux électrodes est à l'origine de la fusion et de la vaporisation des câbles (le matériau isolant comme le métal). Celle-ci est estimée grâce à un calcul thermodynamique à partir de la masse de câble ablatée, en considérant que la totalité a été fondue et que 1% a été vaporisé. La puissance transmise à la colonne d'arc est en partie rayonnée, mais le spectre de longueurs d'onde inférieures à 200 nm est absorbé dès les premiers microns d'air, et une estimation est effectuée à partir du calcul coefficient d'émission nette. Une partie importante de l'étude a porté sur le transfert de l'arc à la plaque en aluminium, en fonction de la distance entre les câbles et cette plaque et selon un critère de température en face arrière, mesurée par thermographie infrarouge. Il a ainsi été montré qu'à pression réduite l'arc est beaucoup plus diffus, et a tendance à s'accrocher à la plaque en aluminium à des distances environ deux fois plus grandes qu'à pression atmosphérique. Cependant, la puissance totale disponible étant inférieure d'environ 20%, les dégâts à la plaque en aluminium sont moins importants
Fault electric arcs occurring between two damaged wires may lead to a phenomenon called "arc tracking", which consists in a maintaining and propagating arc along the cables, causing their progressive ablation. In an aeronautical network, such a fault may have serious consequences if it happens within a wiring harness, especially as it is likely to transfer to a nearby structure. An experimental setup has been developed to study this phenomenon. It consists of a power supply designed in accordance with aeronautical specifications, which enables to generate a direct or alternating signal during an adjustable time. In order to reproduce flight conditions in a better way (low pressure at high altitude), tests are carried out within a closed chamber, whether at 1 bar pressure, or at 95 mbar pressure. Three types of cables are tested, one mainly made of aluminium and two mainly made of copper. In direct regime, they are connected to the + and the - poles of the generator, and to two phases in alternating regime. An aluminium plate, representing the aircraft structure and connected to the neutral in alternating regime, is placed in front of the stripped part of the cables, where the arc occurs, enabling a potential transfer of the arc from the cables toward the plate. Every test involves a systematic acquisition of the current and voltage signals, and two radiative flux sensors are positioned around the arc. A fast camera enables a viewing of the arc behaviour during the test. Finally, the sample is weighed before and after each test. A power balance is realised for the various tested configurations (current, pressure, cables), in order to estimate the distribution of the total power between the electrodes (fusion and vaporisation of the cables, but also conduction and radiation) and the plasma column (radiation, conduction, convection). The amount of power that is transferred to the electrodes is estimated with the value of the electrode voltage drop and the current. Part of this power makes the cables melt and vaporise (the insulating material as well as the metal), it is estimated with a thermodynamic calculation based on the ablated mass of cable, considering that the whole has been molten, and 1% vaporised. The amount of power transmitted to the arc column is partly radiated, but the wavelength spectrum emitted below 200 nm is absorbed through the very first microns in air, and estimation is made involving the calculation of the net emission coefficient. A significant part of the study was related to the transfer of the arc toward the aluminium plate, as a function of the distance between the cables and that plate, and according to a temperature criterion at the back side, by means of infrared thermography. Thus, it was shown that at low pressure, the arc is much less localised, and tends to transfer to the aluminium plate at distances around twice bigger than at atmospheric pressure. However, the total available power is around 20% smaller, and the damage caused to the aluminium plate is less severe

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Dalou, Célia. "Fluorine and chlorine fractionation in the sub-arc mantle : an experimental investigation." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00657297.

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Volatile elements released from the subducting slab play a fundamental role during the formation of arc magmas in the mantle wedge. Advances of melt inclusion studies enlarged the data on volatile abundance in arc magmas, and it is now possible to characterize some volatile contents in arc primary magmas, in particular F and Cl. A recent study of Mt Shasta melt inclusions (LeVoyer et al., 2010) shows that fractionation of F and Cl potentially contains information about arc magma genesis. In order to trace the source of arc magmas, fluorine and chlorine partitioning was investigated. Here, I present new experimental determinations of Cl and F partition coefficients between dry and hydrous silicate melts and mantle minerals: olivine, orthopyroxene, clinopyroxene, plagioclase, garnet and also pargasite and phlogopite. The values were compiled from more than 300 measurements in 24 melting experiments, conducted between 8 and 25 kbars and between 1180 and 1430˚C. The low abundance F, Cl measurements in minerals were done by Cameca IMF 1280 at WHOI using the negative secondary ion mode. The results show that DOpx/meltF ranges from 0.123 to 0.021 and DCpx/meltF ranges from 0.153 to 0.083, while Cl partition coefficient varies from DOpx/meltCl from 0.002 to 0.069 and DCpx/meltCfrom 0.008 to 0.015, as well. Furthermore, DOl/meltF ranges from 0.116 to 0.005 and DOl/meltCl from 0.001 to 0.004; DGrt/meltF ranges from 0.012 to 0.166 and DGrt/meltCl from 0.003 to 0.087 with the increasing water amount and decreasing temperature. I also show that F is compatible in phlogopite DPhl/meltF > 1.2) while DAmp/meltF is incompatible in pargasite DAmp/meltF from 0.36 to 0.63). On the contrary, Cl is more incompatible in phlogopite (DPhl/meltCl > 1.2 on average 0.09 ± 0.02), than in pargasite (DPhl/meltCl from 0.12 to 0.38). This study demonstrates that F and Cl are substituted in specific oxygen site in minerals that lead then to be more sensitive than trace elements to crystal chemistry and water amount variations thus melting conditions. Using those new partition coefficients, I modelled melting of potential sub-arc lithologies with variable quantity aqueous-fluid. This model is able to decipher 1) amount of aqueous-fluid involved in melting, 2) melting induced by fluid or melting of an hydrous mineral-bearing source and 3) melting of either pargasite-bearing lithology or phlogopite-bearing lithology and shows that sources of some primitive melts, for instance from Italy, bear pargasite and phlogopite, while some primitve melts seem to be the results of fluid-induced melts.

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Sobol, O. V., A. A. Andreev, V. A. Stolbovoy, V. E. Fil’chikov, S. N. Grigoriev, and M. V. Volosova. "Effect of Preparation Conditions in the Pressure Range of Atmospheric Nitrogen (2 ... 50) 10-4 Torr on the Structural and Phase State of the Vacuum-Arc Coatings of Mo-N." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35356.

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Nanocrystalline vacuum-arc nitride coatings possess the totality of unique structural states and properties (high hardness, wear resistance, oxidation stability, etc.). The coatings of the Mo-N system show a high hardness and low solubility of nonferromagnetic materials, thereby attracting great interest in their industrial use. Unfortunately, at present there is an apparent lack of information on the regularities of phase-structural state formation in the Mo-N system. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35356

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Singh, S. K. (Sujeet Kumar). "Conservation genetics of the Bengal tiger (Panthera tigris tigris) in India." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526215662.

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Abstract Tigers are endangered in the wild and face increasing threats from habitat loss and fragmentation. The majority of their range occurs in the Indian subcontinent, which is therefore a critical area for tiger conservation. Bengal tigers are distributed across many small protected areas in India. Two important Bengal tiger landscapes — Terai Arc Landscape (TAL) and Sundarbans in India were lacking in basic genetic information and needed to address the impact of anthropogenic pressure and climate change on their genetic makeup in order to identify conservation units. Therefore, I employed nuclear and mitochondrial genetic markers on TAL and Sundarbans tiger individuals to respond these demands for the first time. Thirty-nine heterologous microsatellite loci were screened on Bengal tigers and thirteen of these loci were selected to genotype Bengal tiger samples from western TAL (WTAL) and Sundarbans. After I had genotyped seventy-one Bengal tiger individuals from WTAL, I found cryptic population genetic structure, moderate gene flow and asymmetric migration among the subpopulation. Genetic diversity was moderate and there were no signs of population bottlenecks. In order to maintain the connectivity of subpopulations and avoid human—wildlife conflict, relocation of villages is necessary. Preventive measures against habitat encroachment and a ban on sand and boulder mining in the corridor area should also be implemented. Noninvasively-collected tiger samples from Sundarbans were analyzed for mitochondrial and microsatellite markers and compared with mainland (northern and peninsular) Bengal tiger populations in India. Sundarbans tigers were found to be genetically distinct and had lower genetic variation in comparison to other mainland tiger populations. Demographic analysis indicated recent historical isolation (600—2000 years ago) of the Sundarbans tiger from the mainland. Both historical and genetic evidence supported that the Sundarbans tiger was genetically connected to other mainland tigers until recently. Conclusively, genetic isolation from the mainland tiger population and adaptation to the mangrove ecosystem might have jointly shaped the genetic architecture of the Sundarbans tiger. Hence, the Sundarbans tiger needs special conservation attention for the preservation of its unique ability to adapt and for its genetic individuality. It should be managed as an evolutionary significant unit (ESU) under the adaptive evolutionary conservation (AEC) criteria. I also addressed a problem in the previously suggested sex-specific gene flow estimation method and recommended an alternative approach for a more precise estimation
Tiivistelmä Tiikeri on nykyisin uhanalainen lajin elinympäristön supistumisen ja pilkkoutumisen vuoksi. Lajin tärkein esiintymisalue on Intian niemimaalla, joka on siten kriittisen tärkeä alue tiikerin suojelun kannalta. Intiantiikereitä esiintyy useilla pienillä suojelualueilla Intiassa. Kaksi tärkeää tiikerin esiintymisaluetta Intiassa ovat Terain kaaren (TAL) alue luoteis-Intiassa sekä Sundarbansin mangrovealue Bangladeshin rajalla. Näiden alueiden tiikereistä ei ole ollut olemassa geneettistä perustietoutta, jota tarvitaan, kun arvioidaan ihmisen toiminnan ja ilmastonmuutoksen aiheuttamia muutoksia tiikeripopulaatioiden geneettisessä koostumuksessa sekä kun määritellään lajin suojelun kannalta merkittäviä luonnonsuojeluyksikköjä. Tässä väitöskirjatutkimuksessa tutkittiin Terain kaaren ja Sundarbansin alueen tiikereiden geneettistä monimuotoisuutta ja rakennetta sekä tuman että mitokondrion geenimerkkien avulla. Tutkimuksessa selvitettiin kolmenkymmenyhdeksän tuman geenimerkin (mikrosatelliitin) soveltuvuutta intiantiikerin geneettisiin tutkimuksiin, ja näistä valittiin kolmetoista käytettäväksi läntisen Terain kaaren ja Sundarbansin alueiden tiikereiden geneettisiin tutkimuksiin. Terain kaaren alueelta tutkittiin seitsemänkymmenentäyksi intiantiikerinäytettä. Tulosten perusteella alueella on aikaisemmin havaitsematonta kryptistä populaatiorakennetta. Geenivirtaa eri alapopulaatioiden välillä oli kohtuullisen paljon, mutta se oli epäsymmetristä. Tiikereiden geneettinen monimuotoisuus oli melko suurta eikä geneettisillä menetelmillä havaittu eri alapopulaatioissa merkkejä populaation koon pullonkauloista. Jotta alapopulaatioiden välinen yhdistyneisyys säilyisi jatkossa, joidenkin kylien siirto toisaalle on välttämätöntä. Ihmisten luvaton levittäytyminen tiikerin elinalueita yhdistävillä käytävillä täytyisi saada hallintaan sekä kieltää hiekanotto ja kivenlouhinta. Sundarbansin alueelta ei-invasiivisesti kerätyt tiikerinäytteet tutkittiin sekä tuman että mitokondrion merkkigeenillä ja alueen tiikereiden geneettistä koostumusta verrattiin manner-Intian tiikeripopulaatioiden koostumukseen. Sundarbansin tiikereiden todettiin poikkeavan geneettisesti manneralueen tiikeripopulaatioista ja niiden geneettinen monimuotoisuus oli alhaisempaa kuin manneralueella. Koalesenssisimulaatiohin perustava demografinen analyysi viittasi Sundarbansin tiikereiden suhteellisen viimeaikaiseen (600—2000 vuotta sitten) erkanemiseen manneralueen tiikereistä. Sekä historialliset että geneettiset todisteet tukivat teoriaa, jonka mukaan Sundarbansin tiikereillä olisi ollut yhteyksiä mannermaan tiikereihin aivan viime aikoihin asti. Geneettinen isolaatio mannermaan tiikereistä ja adaptaatio mangrove-ekosysteemiin ovat yhdessä muovanneet Sundarbansin tiikereiden geneettistä arkkitehtuuria. Tämän vuoksi Sundarbansin tiikerit vaativat erityistä suojelua, jotta niiden geneettinen ainutlaatuisuus ja kyky sopeutua erityisolosuhteisiin säilyisivät myös tulevaisuudessa. Populaatiota täytyy hoitaa evolutiivisesti merkittävänä yksikkönä (evolutionary significant unit; ESU) adaptiivisen evolutiivisen suojelun (adaptive evolutionary conservation; AEC) kriteeristön mukaisesti. Tutkimuksessa kiinnitettiin huomiota myös ongelmiin, joita saattoi ilmetä aikaisemmin ehdotetuissa menetelmissä eri sukupuolten kautta kulkevan geenivirran määrän arvioimiseksi ja ehdotettiin vaihtoehtoista menetelmää tarkempien arvioiden saamiseksi

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Quéméneur, Jean. "Etude des forces à l'origine du déplacement d'un arc électrique dans un disjoncteur basse-tension." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30040/document.

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Le Disjoncteur Basse-Tension (DBT) est un appareil classique de la distribution électrique depuis plus de cinquante ans. Mais aujourd'hui, avec l'arrivée de produits bas-coût fabriqués dans les pays émergents, les industriels sont soumis à une forte pression pour développer de nouveaux systèmes moins encombrants, utilisant d'autres matériaux, ou incorporant davantage de fonctionnalités. Cette recherche est très compliquée dans la mesure où le DBT est un système hautement multi-physique (mécanique, thermique, physique des matériaux, physique des plasmas, ...). De fait, le développement de nouveaux produits passe par un processus empirique long et coûteux. Cet effort pourrait être réduit par l'utilisation de modèles prédictifs permettant d'arriver plus vite à un système fonctionnel. De nos jours, avec l'augmentation des moyens de résolution numérique, de plus en plus de travaux portent sur la description multi-physique en 3D du DBT et notamment sur la chambre de coupure ou l'arc électrique est amorcé, se déplace et doit être éteint, l'objet de nôtre étude. Le travail de cette thèse se divise en deux axes complémentaires : le développement d'un modèle fluide 3D en méthode des volumes finis simulant l'arc électrique et son déplacement dans la chambre de coupure; ainsi que la mise en place d'un dispositif expérimental permettant d'analyser le phénomène physique en œuvre. Pour ces deux points la problématique est abordée dans une configuration simplifiée de DBT où l'arc se déplace entre deux rails parallèles dans une chambre parallélépipédique. Basé sur le savoir-faire du groupe AEPPT, un modèle numérique est établi pour simuler le plasma thermique. Les particularités de ce modèle, du fait de l'application, sont la nécessité d'une résolution précise du champ magnétique en utilisant le calcul de Biot & Savart pour les conditions limites ainsi que l'utilisation de méthodes permettant le déplacement et la commutation de l'arc. La validation de ce modèle se fera à géométrie similaire par confrontation avec l'expérience. En s'inspirant de précédents travaux nous avons réalisé une maquette expérimentale composée d'un réacteur faisant office de chambre de coupure et d'un mécanisme permettant l'amorçage de l'arc dans le réacteur par ouverture rotative du contact à vitesse contrôlée. D'autres paramètres modifiables sont la taille du réacteur ainsi que les matériaux qui le constituent. Les diagnostiques disponibles en plus de la mesure de courant et de tension sont l'imagerie rapide et la mesure de pression en différents points de la chambre de coupure. Notre expérience est utile pour la réalisation d'études paramétriques en découplant facilement les paramètres. En outre, par la mise en évidence des phénomènes prépondérants, notre maquette aide à la mise en place du modèle en plus de permettre sa validation expérimentale. Cette thèse est donc une étape cruciale vers la mise en place d'un modèle prédictif
Low-Voltage Circuit Breakers (LVCB) are classical apparatuses of electrical distribution since more than fifty years. But nowadays, with the outbreak of low-cost products from the developing countries, industry is under a strong stress in order to improve their devices by making them more compact, using different materials or to implement new functionalities. This research is harsh since LVCB are highly multiphysics systems (mechanics, thermal properties, materials, plasma physics, ...). Therefore, developing new products goes through a long and expensive empirical process. Those efforts could be reduced by using predictive models allowing to get faster to a functional device. With the improvements of the numerical solution capacity, there are more and more works toward the 3D multiphysical description of the LVCB, especially on the extinction chamber where the electrical arc is ignited, moved and must be quenched. This is the subject of our work. The study described here is divided in two complementary parts: development of a 3D fluid model with finite volume method simulating the electrical arc and its movement inside the arc extinction chamber; and the set-up of experimental means to analyse this physical phenomenon. For those two points, we use a simplified LVCB configuration with an arc moving between two parallel rails inside a rectangular box chamber. Based on AEPPT's know-how, a numerical model is established to simulate thermal plasma. Particularities on this model, due to the application, are the resolution of Biot&Savart law to calculate precisely the magnetic field for the boundary condition and the development of methods to model the arc roots movement and commutation of the arc from the moving contact to the rail. Validation of this model will be done with the same geometry by confrontation with the experiment. Inspired by precedent works we designed a test apparatus with a reactor representing the extinction chamber of the LVCB and an opening mechanism allowing arc ignition by contact opening at a specified speed. Other parameters such as size of the chamber and materials can be modified. Measurements will include high speed imaging and pressure acquisition in several points of the reactor in addition to the classical current and voltage measurements. This experiment is useful for parametric studies with its easy uncoupling of the parameters. Moreover, by highlighting the dominating phenomena for arc movement, this set-up helps in the build-up of the model over and above the experimental validation

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Kanjanasakul, Chanisa. "Analysis of the optical properties of droplets of different fluids in high-pressure environments by rainbow optical diagnostic." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR22/document.

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La caractérisation des propriétés optiques de gouttes de combustible aux alentours de la pression critique est un défi. L’objectif de la thèse est de mesurer la taille et l’indice de réfraction de fluides dans des conditions de pression élevée proche du point critique. A cet effet, une installation expérimentale d’injection de gouttes à haute pression a été conçue. La réfractométrie d’arc-en-ciel a été développée et adaptée pour travailler d’abord sur des gouttelettes d’eau et d’éthanol dans le domaine de pression 1 - 40 bar. Des évolutions de leur indice de réfraction avec la pression ont été obtenues. Pour les mesures se rapprochant d’un fluide proche du point critique, l’éthane a été sélectionné car son point critique est à 48,7 bar et 32,2°C. Des mesures de réfraction d’index sur des gouttes liquides d’éthane ont ensuite été réalisées dans le domaine 40 - 46 bar et 18 - 25°C. Une mesure de l’indice de réfraction de gouttes d’éthane donne alors une valeur de 1,255 ± 0.002
The characterization of the optical properties of fuel drops around the critical pressure is a challenge. The aim of the thesis is to measure the size and the refractive index of fluids under high pressure conditions close to the critical point. For this purpose, an experimental installation of injection of high-pressure drops has been designed. Rainbow refractometry has been developed and adapted to work first on water and ethanol droplets in the pressure range 1 - 40 bar. Evolutions of their index of refraction with the pressure were obtained. For measurements approaching a fluid near the critical point, ethane was selected because its critical point is 48.7 bar and 32.2 ° C. Index refractive measurements on liquid drops of ethane were then carried out in the range 40 - 46 bar and 18 - 25 ° C. A measurement of the refractive index of ethane drops then gives a value of 1.255 ± 0.002

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Kobielusz, Petr. "Městský okruh Blanka, tunel Královská obora - ražená část, stavebně technologická příprava stavby." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226100.

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My thesis is focused on process preparation and building construction technology of primary lining road tunnel, implemented in city part of Troja in the capital city Prague. Specifically it is a part of tunnel complex Blanka. The name of this part is Kralovská obora. If the all tunnel parts are built this tunnel complex Blanka can be complemented to already opened tunnels Zlíchovský, Mrázovka and Strahovský which are the part of city traffic circle. This technology preparation includes schedules and financial plans of the building, technological prescription for the primary tunnel lining, safety plan, control and trial/test plans, environmental plan, project of construction site, design of the main working machines, items budget of the north tunnel tube, coordination situation plan with wider relationships transport routes and technical report of building technological project.

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Richard, Frédéric. "Etude et caracterisation d'une decharge electrique glissante dans l'air a pression atmospherique." Orléans, 1995. http://www.theses.fr/1995ORLE2061.

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Les arcs glissants qui se deplacent dans un ecoulement de gaz entre deux electrodes profilees en forme de tuyere permettent d'obtenir a la pression atmospherique et aux pressions plus elevees des plasmas hors equilibre caracterises a la fois par de fortes densites electroniques (superieures a 10#1#4 cm#-#3) et des champs electriques eleves de l'ordre de 10#4 v/m. Ces dispositifs sont interessants et prometteurs pour de nombreuses applications industrielles dans le domaine de la plasma chimie (destruction des composes organiques volatils (cov), desulfuration des gaz et reduction de h#2s, valorisation du methane, transformation du protoxyde d'azote n#2o en no#x). Ce travail porte sur l'etude d'une telle decharge alimentee a partir d'une source electrique continue, dans l'air a pression atmospherique. Plusieurs methodes de diagnostics ont ete utilisees (photographie rapide avec une camera dtc intensifiee, capteurs optoelectroniques, mesures electriques, spectrometrie moleculaire). Les resultats obtenus ont montre que le comportement de ces decharges peut etre decrit a l'aide de modeles relativement simples et ont permis de mettre en evidence les differents parametres importants qui caracterisent le fonctionnement du dispositif (debit de gaz, tension, intensite du courant, distance minimale des electrodes). L'arc glissant peut etre decrit comme un fin cordon de plasma (diametre 1 mm) a haute temperature (6000 k), entoure d'une gaine plasmagene a plus basse temperature (3000 k) hors equilibre et contenant de nombreuses especes moleculaires excitees. Celui-ci se deplace et s'allonge sous l'effet des forces d'entrainement exercees par le flux de gaz. Une difference de vitesse importante entre le gaz et l'arc glissant produit un refroidissement efficace et deplace le regime de fonctionnement depuis le regime d'arc vers un regime de decharge luminescente. La tension aux bornes de l'arc augmente proportionnellement a son allongement et la tension maximale atteinte, correspond a la tension de claquage au col des electrodes (tension de paschen) qui provoque l'amorcage d'un nouvel arc. Cette etude constitue un progres significatif dans la connaissance des phenomenes physiques associes a l'arc glissant. Cependant, le dernier chapitre de ce travail qui est consacre a l'etude de la formation de no#x dans l'arc, revele l'ampleur du travail restant a accomplir pour maitriser parfaitement les phenomenes physico-chimiques intervenant dans ce type de decharge

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Houšť, Vladimír. "Tenkostěnné přesypané konstrukce." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-234547.

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The thesis is devoted to analysing of flexible buried arch structures. Modelling of the flexible concrete arch is carried out via a nonlinear finite element model that accounts for soil constitutive relations, soil-structure interactions, sequential construction stages and soil compaction. Advanced FE-model was verified by measurement obtained by full-scale field testing of two buried arches. Mathematical optimization methods of genetic algorithms and Levenberg-Marquardt method are applied to already calibrated complex computational models in order to reduce bending and associated flexural stresses in the concrete section of buried arch. Centre line of the arch is parameterized by cubic Bezier curve to reach interpolation of thrust line. Optimization technique is applied with extensive parametrical study which shows the optimal shapes for buried arches of various span/rise ratios, backfill depths and foundation soil types. For practical application are given coordinates of Bézier curve control polygons of particular resulting shape. Subsequently is applied optimization method for a theoretical reduction of tensile stresses obtained by shape optimization of previously verified numerical model of buried arch. Comparisons of earth pressure, bending moment axial force and deflection of flexible structure during sequential construction of different span/raise ratios of buried arches are presented. The behaviour of flexible buried arch with effect of local traffic load model LM1 has been analysed via 3D finite elements model with respect to different depth of backfill above crown.

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Cann-Moisan, Christine. "Etude par HPLC des nucléotides énergétiques chez la truite arc-en-ciel (Salmo gairdneri, R. ) à deux stades de son développement : exemple d'influence d'un facteur de l'environnement : la pression hydrostatique." Brest, 1989. http://www.theses.fr/1989BRES2006.

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31

Liu, Yung-Chun. "Tectonics of Saturn's Moon Titan AND Tsunami Modeling of the 1629 Mega-thrust Earthquake in Eastern Indonesia." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5731.

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Chapter 1-2:The Cassini RADAR mapper has imaged elevated blocks and mountains on Titan we term ‘ridges’. Two unresolved problems regarding Titan's surface are still debated: what is the origin of its ridges and was there tectonic activity on Titan? To understand the processes that produced the ridges, in this study, (1) we analyze the distribution and orientation of ridges through systematic geomorphologic mapping and (2) we compare the location of the ridges to a new global topographic map to explore the correlation between elevation and ridges and the implications for Titan's surface evolution. Globally, the orientation of ridges is nearly E-W and the ridges are more common near the equator than at the poles, which suggests a tectonic origin for most of the ridges on Titan. In addition, the ridges are found to preferentially lie at higher-than-average elevations near the equator. We conclude the most reasonable formation scenario for Titan's ridges is that contractional tectonism built the ridges and thickened the icy lithosphere, causing regional uplift. The combination of global and regional tectonic events, likely contractional in nature, plus enhanced fluvial erosion and sedimentation near the poles, would have contributed to shaping Titan's tectonic landforms and surface morphology to what we see today. However, contractional structures (i.e. thrusts and folds) require large stresses (8~10 MPa), the sources of which probably do not exist on Titan. Liquid hydrocarbons in Titan's near subsurface must play a role similar to that of water on Earth and lead to fluid overpressures, which enable contractional deformation at smaller stresses (< 1MPa) by significantly reducing the shear strength of materials. We show that crustal conditions with enhanced pore fluid pressures on Titan favor the formation of thrust faults and related folds, in a contractional stress field. The production of folds, as on Earth, is facilitated by the presence of crustal liquids to weaken the crust. These hydrocarbon fluids have played a key role in Titan's tectonic evolutionary history, leaving it the only icy body on which strong evidence for contractional tectonism exists. Chapter 3: Arthur Wichmann's ‘Earthquakes of the Indian Archipelago’ documents several large earthquakes and tsunami throughout the Banda Arc region that can be interpreted as mega-thrust events. However, the source regions of these events are not known. One of the largest and well-documented events in the catalog is the great earthquake and tsunami affecting the Banda islands on 1 August 1629. It caused severe damage from a 15-meter tsunami that arrived at the Banda Islands about a half hour after violent shaking stopped. The earthquake was also recorded 230 km away in Ambon, but no tsunami is mentioned. This event was followed by at least 9 years of uncommonly frequent seismic activity in the region that tapered off with time, which can be interpreted as aftershocks. The combination of these observations indicates that the earthquake was most likely a mega-thrust event. We use an inverse modeling approach to numerically reconstruct the tsunami, which constrains the likely location and magnitude of the 1629 earthquake. Only linear numerical models are applied due to the low-resolution of bathymetry in the Banda Islands and Ambon. Therefore, we apply various wave amplification factors (1.5 to 4) derived from simulations of recent, well-constrained tsunami to bracket the upper and lower limits of earthquake moment magnitudes for the event. The closest major earthquake sources to the Banda Islands are the Tanimbar and Seram Troughs of the Banda subduction/collision zone. Other source regions are too far away for such a short arrival time of the tsunami after shaking. Moment magnitudes predicted by the models in order to produce a 15 m tsunami are Mw of 9.8 to 9.2 on the Tanimbar Trough and Mw 8.8 to 8.2 on the Seram Trough. The arrival times of these waves are 58 minutes for Tanimbar Trough and 30 minutes for Seram Trough. The model also predicts 5 meters run-up for Ambon from a Tanimbar Trough source, which is inconsistent with the historical records. Ambon is mostly shielded from a wave generated by a Seram Trough Source.We conclude that the most likely source of the 1629 mega-thrust earthquake is the Seram Trough. Only one earthquake > Mw 8.0 is recorded instrumentally from the eastern Indonesia region although high rates of strain (50-80 mm/a) are measured across the Seram section of the Banda subduction zone. Enough strain has already accumulated since the last major historical event to produce an earthquake of similar size to the 1629 event. Due to the rapid population growth in coastal areas in this region, it is imperative that the most vulnerable coastal areas prepare accordingly.

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32

Standley, Carl Eldon. "Banda Forearc Metamorphic Rocks Accreted to the Australian Continental Margin: Detailed Analysis of the Lolotoi Complex of East Timor." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1304.

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Petrologic, structural and age investigations of the Lolotoi Complex of East Timor indicate that it is part of a group of thin metamorphic klippen found throughout the region that were detached from the Banda forearc and accreted to the NW Australian continental margin during Late Miocene to Present arc-continent collision. Metamorphic rock types are dominated by (in order of greatest to least abundance), greenschist, graphitic phyllite, quartz-mica schist, amphibolite and pelitic schist. Mineral, whole rock, and trace element geochemical analyses of metabasites indicate that protolith compositions are consistent with tholeiitic basalt and basaltic andesite with mixed MORB and oceanic arc affinities. Metapelitic schist compositions are consistent with mafic to intermediate oceanic to continental arc provenance. Geothermobarometric calculations show peak metamorphic temperatures in pelitic rocks range from 530°C to 610°C for garnet-biotite pairs and peak pressures of 5 to 8 kbar for garnet-aluminosilicate-quartz-plagioclase assemblages. Analyses of amphibole in amphibolites yield temperatures of 550°C to 650°C and pressures of 6 to 7 kbar. Lu-Hf analyses performed on garnet samples from two massifs in East Timor yielded four ages with a mean of 45.36 ± 0.63 Ma, which is interpreted to represent the approximate age of peak metamorphism. Detrital zircons from one amphibolite sample in East Timor yields a bimodal U-Pb age distribution of 560 Ma and 80 Ma, indicating deposition occurred after the 80 Ma closure of the zircon grains. The sequence of deformation as indicated by field measurements is similar to that reported from other klippen throughout the Timor region. Contact relationships with adjacent units indicate that the metamorphic terrane is in thrust contact with underlying Gondwana Sequence rocks. Overlying the metamorphic rocks are Asian affinity volcanic and sedimentary cover units found mostly in normal fault contact on the edges of Lolotoi Complex klippen. Geochemical, age, petrological and structural data imply the Lolotoi Complex formed part of the eastern Great Indonesian arc, which began to collapse in the Eocene, was incorporated into the Banda arc in the Miocene, and accreted to the Austrailian continental margin from Pliocene to Present.

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33

Favier, Alexiane. "Évolution spatio-temporelle de l'hydrothermalisme dans la plaque supérieure de l'arc des Petites Antilles en Guadeloupe : applications aux systèmes géothermaux." Thesis, Antilles, 2019. http://www.theses.fr/2019ANTI0401.

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Pour poursuivre le développement de la géothermie de haute-enthalpie dans l’arc insulaire des Petites Antilles il faut d’une part identifier de nouvelles zones potentielles et d’autre part mieux comprendre le fonctionnement des réservoirs géothermaux. Dans ce cadre, l’objectif de cette thèse est de caractériser l’évolution spatio-temporelle de l’hydrothermalisme au niveau de la plaque supérieure de l’arc en Guadeloupe au travers d’une analyse pluridisciplinaire (études structurales, géochimiques, minéralogiques, pétrologiques et géochronologiques) des complexes volcaniques les plus anciens de l’archipel. Au Nord de la Basse-Terre nous identifions un métamorphisme d’arc de type sub-Schistes Verts. L’état thermique standard de la croûte d’arc en Guadeloupe ainsi établit indique une transition fragile-ductile située à 3-4 km de profondeur. Un paléo-réservoir exhumé, identifié au Sud de l’île de la Basse-Terre, illustre un métamorphisme hydrothermal de type Schistes-Verts synchrone du développement de couloirs de schistosité et révèle la présence d’horizons verticaux et latéraux de transfert de fluides hydrothermaux situés à 2-3 km de profondeur. En comparant l’âge du volcanisme et la datation Ar-Ar des phases hydrothermales de haute-température, nous estimons une durée maximale de fonctionnement du paléo-réservoir à 650 ka. Enfin, la découverte, l’analyse et la datation K-Ar d’une nouvelle brèche hydrothermale, au coeur du système géothermal actif, met en évidence un système épithermal distal relié à l’activité volcanique de la Soufrière. Nos résultats conduisent à un modèle conceptuel de fonctionnement d’un réservoir géothermal de haute-énergie en contexte d’arc actif
To further develop high-enthalpy geothermal energy in Lesser Antilles arc, it is necessary to identify possible new key targets, and to better understand the modes of fluids and heat transfers in geothermal reservoirs. The objective of this work is thus to characterize the spatio-temporal evolution of hydrothermalism at the upper plate of the arc in Guadeloupe with a multidisciplinary approach (combined structural, geochemical, mineralogical, petrological and geochronological analyses) focussed on the oldest volcanic complexes of the archipelago. In the north of Basse-Terre Island reveals an arc metamorphism developed under sub-Greenschist facies. The standard thermal state of the arc crust in Guadeloupe thus established shows a brittle-ductile transition located at depths of 3 to 4 km. An exhumed geothermal paleo-reservoir, identified at the south of Basse-Terre Island, indicates a hydrothermal metamorphism developed under Greenschist facies synchronous with the development of schistose corridors and attests for both vertical and lateral hydrothermal fluid transfers at depths between 2 and 3 km. Comparison of the age of the volcanic activity and Ar-Ar dating of the high-temperature hydrothermal phases allows us to estimate a maximum operating time of the paleo-reservoir at 650 ka. Finally, the discovery, the analysis and the K-Ar dating of a new hydrothermal breccia, within the active geothermal system, reveals a link between current geothermal activity and volcanic activity of the Soufrière, interpreted as a distal epithermal system. Our results lead to a conceptual model for the operation of a high-energy geothermal reservoir in the context of an active arc

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34

Rogler, Daniela. "Entwicklung einer lichtbogengestützten PECVD-Technologie für die Synthese siliziumbasierter Schichtsysteme unter Atmosphärendruck – Untersuchung des diffusionslimitierten Wachstumsregimes." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-97547.

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Atmosphärendruckplasmen sind aufgrund ihrer vergleichsweise einfachen Anlagentechnik, potentiell geringen Betriebs- und Investitionskosten sowie ihrer Flexibilität bezüglich Substratgröße seit vielen Jahren von großem Interesse. Die Nutzung von Plasmaquellen mit hoher Precursoranregungseffizienz und ausgedehnter Beschichtungszone ist in diesem Zusammenhang besonders vorteilhaft. In der vorliegenden Arbeit wird deshalb erstmals eine neuartige Langlichtbogenplasmaquelle vom Typ LARGE (Long Arc Generator) zur plasmagestützten Synthese von Schichten bei AP (Atmosphärendruck) eingesetzt. Bei der Remoteaktivierung des Precursors erweisen sich insbesondere sauerstoff- sowie stickstoffhaltige Plasmagase als geeignet, um einen signifikanten Anteil der Plasmaenergie in den Remotebereich zu transferieren. Die entwickelte bogenbasierten PECVD (Plasma Enhanced Chemical Vapour Deposition) unter Atmosphärendruckbedingungen ist durch die Erzeugung hochenergetischer Plasmen gekennzeichnet, der Precursor wird stark fragmentiert und ursprüngliche Bindungen des Precursormoleküls werden vollkommen aufgebrochen. Die Ergebnisse der Gasphasencharakterisierung mittels optischer Emissions- sowie Infrarotspektroskopie lassen beim Prozess der Precursorfragmentierung im Remoteplasma auf eine zentrale Bedeutung metastabiler sowie dissoziierter Spezies schließen. Weiterhin sind hohe Plasmaleistungen, Molekulargasanteile im Plasmagas und große Plasmagasflüsse für eine wirkungsvolle Remoteaktivierung des Precursors von Vorteil. Einen wichtigen Aspekt des Verfahrens stellt darüber hinaus die Möglichkeit der Synthese sauerstofffreier Schichtmaterialien dar. Es konnte gezeigt werden, dass sowohl der genutzte Atmosphärendruckreaktoraufbau mit seinem Gasschleusenkonzept, als auch die Gasreinheit des verwendeten Prozessgases zu keiner nennenswerten Einlagerung von Sauerstoff in die Schicht führt. Die Schichthärte synthetisierter Siliziumnitrid-Schichten lässt sich ohne zusätzliche Substratheizung durch Prozessparameteroptimierung bis auf eine Härte von 17 GPa steigern. Die dynamische Abscheiderate ist mit 39 nm∙mm/s ebenfalls für eine technische Anwendung ausreichend hoch. Eine eingehende Analyse aller Daten legt den Schluss nahe, dass das Schichtwachstum bei der Atmosphärendruck Remote-PECVD häufig kinetisch gehemmt ist und nicht im thermodynamischen Gleichgewicht stattfindet. Der Wachstumsprozess ist in diesem Fall durch das Phänomen des DLG (Diffusion Limited Growth) gekennzeichnet. Homogennukleation bzw. Gasphasennukleation spielt anders als bislang angenommen auch bei Atmosphärendruckbedingungen keine bzw. eine nur untergeordnete Rolle und ist damit nicht limitierend für die erzielbare mechanische und chemische Stabilität der gebildeten Schichten. Mit steigender Diffusionslimitierung des Schichtbildungsvorganges wird eine Zunahme der Schichtrauheit beobachtet, daraus und aus dem Zuwachs an strained sowie dangling Bonds in der Schicht resultiert eine gesteigerte Affinität der synthetisierten Schichten gegenüber Sauerstoff. Als Schlüsselparameter bezüglich Schichtmorphologie sowie Topographie wird der DLG-Quotient angesehen, welcher das Verhältnis aus Oberflächendiffusionskoeffizient und Auftreffrate schichtbildender Spezies auf dem Substrat darstellt. Damit wurden im Rahmen dieser Arbeit die entscheidenden und verfahrenslimitierenden Aspekte identifiziert und die Grundlage für die weitere Optimierung dieses und anderer Remote-AP-PECVD-Verfahren geschaffen. In ähnlicher Weise wie dies auch durch die Bereitstellung einer verbesserten thermischen Aktivierung des Diffusionsprozesses schichtbildender Spezies auf der Substratoberfläche geschieht, lässt sich mit Hilfe eines niedrigen Stickingkoeffizienten eine Diffusionslimitierung des Schichtbildungsvorgangs bei AP-PECVD unterdrücken. In diesem Zusammenhang besitzt insbesondere Ammoniak im Remotegas einen günstigen Einfluss auf die entstehende Schichtmorphologie und Konformalität der Beschichtung.

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35

Boulanger, Vincent. "Pression d'herbivorie et dynamique des communautés végétales : Influence à court et moyen termes des populations de cervidés sur la diversité des communautés végétales en forêt." Phd thesis, Nancy 1, 2010. http://tel.archives-ouvertes.fr/tel-00518080.

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Les cervidés, animaux mobiles et herbivores, peuvent influencer les distributions, assemblages et dynamiques d'espèces végétales. L'objectif de cette thèse est d'évaluer le rôle joué par les cervidés sur la composition, stratification et dynamique de la végétation forestière. Le ré-échantillonnage de relevés couplant composition et abroutissement de la flore, implantés en 1976 en Forêt d'Arc-en-Barrois (52) a permis d'identifier (i) des espèces ligneuses préférées (Cornus sp., Rosa arvensis ) ou au contraire évitées par les cervidés qui sélectionnent les espèces arbustives et à bois dense et (ii) le niveau trophique et la pression d'abroutissement comme gradients structurant la végétation et déterminant les dynamiques des espèces et des communautés. Nous analysons plus précisément le rôle des cervidés dans la progression spectaculaire de Cynoglossum germanicum, espèce rare, épizoochore et toxique.A partir d'un réseau national d'enclos/exclos suivis sur 10 ans, nous montrons que les cervidés limitent la croissance des arbustes et des espèces compétitrices, ce qui profite à la richesse spécifique de la strate herbacée. La valeur écologique et patrimoniale des espèces en progression est discutée. A l'aide de données de chasse, nous tentons d'isoler les rôles des différentes espèces d'ongulés dans ces dynamiques.Ces résultats exposent la complexité et la diversité des effets des cervidés sur la végétation forestière. Enfin, ce travail met l'accent sur la nécessité des suivis temporels intégrant toutes les composantes de l'écosystème forestier pour mieux appréhender les changements en cours.

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36

Wang, Bing-Cherng, and 王炳誠. "Earthquake Induced Hydrodynamic Pressure on Arch Dams." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/72024110545128093647.

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37

KANG, CHIN-YUAN, and 康晉源. "Development of a System to Micro-Adjust Pressure Distribution with Arch Pad." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/79630053049321692112.

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38

Chang, Chun-Ching, and 張志清. "The effect of arch support for planus in rearfoot motion and plantar pressure." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/47097828267534800137.

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碩士
國立中央大學
機械工程學系
85
Abstract******************************************************** ***** Foot can divide into cavus,normal and planus according the height of foot arch.What is called the planus is specially lower in arch height.In normal working,the planus makes large range of motion in rearfoot and height plantar peak pressure on outside metatarsal than normal due to lower arch .And it may make pathological foot in future.In hospital,some suggest that use arch support to improve the defect and some don''t.At present,there isn''t any report about arch support using in planus.So,the main purposeof the thesis is to research the effect of arch support for planus and hope to support reasonable reference when doctor do correcting. For safety,the thesis use footprint including arch index and modified arch index to be a standard for assessing planus.The conditions of experiment include shoe and shoe with 4 fifferent arch support. According to the experiment result of five planus subjects,arch support can reduce the range of motion in rearfoot motion for most subjects.In plantar pressure,the effect of arch support isn''t significant and don''t reduce the peak pressure on outside metatarsal.In gait line,it is almost the same for all conditions.So,according the result,it seems right to use arch support to improve the planus.

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39

Wang, Tse-Hsiang, and 王則翔. "On the Development of the Optical Measurement System for Plantar Pressure and Arch Index." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/93762660275742301785.

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碩士
國立臺灣大學
應用力學研究所
103
The Plantar pressure and arch index of patient for pathological analysis is an important issue in biomechanical field. The results can be used for preventing and treating some diseases like diabetes and paralysis. There were some used plantar pressure measurement methods in clinical research. Harris foot mat use rubber cushion to measure subject’s plantar pressure. Another method adopted electrical pressure sensors to measure the plantar pressure through the changes of electrical resistance and capacitance. In addition, optical system used photo or plastic sensing units to measure plantar pressure. Although the cost of optical measurement system was cheaper than the electric system, the capability of optical system for measuring pressure values performed worse than electric ones. Besides, the present optical system needs auxiliary structure to measure plantar pressure. This study tried to use gray level analysis to build a new system to improve the defect of measuring pressure values, and simplify process of system. This work develops a new optical plantar pressure and arch index measurement system. Instead of the existing photo or plastic sensing units, the present system uses digital optical camera to capture the color change of bare foot standing. Use gray level transformation and image-processing techniques to establish a correlation relation between the plantar pressure and gray level. Furthermore, measuring the divided region surface of foot can easily get arch index. We can measure the pressure distribution, arch index, length, and width of foot through our system. The simple composition of system and interface can help operators to get plantar information of users more convenient than other used methods. Besides, the data measured by this system can be conserved though data base of users and could be applied for foot disease prevention in the future.

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40

Chiu, Chi-cheng, and 邱繼正. "The Study of Double Arch Structure Pressure Fiber Sensor Based on Fiber Bragg Grating." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/56372270915719097468.

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碩士
國立高雄第一科技大學
光電工程研究所
100
In this paper, the fiber Bragg grating (FBG) sensor for strain sensing is discussed. When the sensor is subject to strain, the central wavelength of the FBG may drift, which can reflect the magnitude of the strain. In this study, a special exterior design and package of the sensor are used so that the period of FBG can be changed as pressure is applied, which in turn causes the central wavelength of the reflection spectrum to drift. By analyzing the drift of the central wavelength, the sensed value can be deduced. Based on the structural analysis and experimental results of the pressure sensor discussed in this study, with the arch shape of the exterior structure of the sensor as well as the H-shaped diaphragm, the longitudinally distributed pressure can be converted into the lateral strain of the diaphragm. And then the diaphragm can transfer the strain to the FBG so as to measure the longitudinally applied pressure. The experimental results show that the wavelength drift and the applied positive pressure are highly positively correlated with a correlation coefficient of 0.9983 and pressure sensitivity up to 3.852 ×10- 3 MPa-1.

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41

CHEN, YU-TING, and 陳裕廷. "Influence of Far-infrared Arch Corrective Insoles on Walking Gait and Blood Pressure for the Elderly." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/12828268246771952074.

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42

Lo, Hsien-Chung, and 羅憲宗. "Construction the System of Image-base Plantar Pressure and Arch Measurement and Database forArch Correction Using Insole Adjustment." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/ymn637.

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博士
國立臺南大學
電機工程學系碩博士班
107
Foot health is an important part of personal physical activity. From a medical point of view, poor walking posture can cause physical illness. The plantar pressure information can analyze the individual walking gait and posture. For the average person, it is not easy to obtain your own plantar information and the plantar image map, especially the possession and query, which highlights the importance of the plantar information, so we study the smart phone application (application, APP) has been developed to be easy to operate, low in cost, and popular to use. In the development of the arch corretion, any auxiliary equipment that can be connected through the Arduino motherboard and can produce timely processing and precision can accurately and quickly process the pressure center of gravity measurement data through the LCD display. The advantage of using the fine-tuning auxiliary system is that the data is processed efficiently, the operation is convenient, and the adjustment is accurate. Taking the children in the development of the arch as the experimental object, the results were analyzed and the important information of the correction of the arch of the child was obtained. The purpose of this paper is to develop and establish a foot-image image conversion foot and foot arch index data record analysis software, and build a database through the smart phone application (application, APP) software architecture. It is easy to carry, and software development is easier and less costly. Therefore, this development platform is used. And develop the arch correction tool fine-tuning software arch index database, through the cloud to update the data at any time, and thus provide a record change in the correction process of the plantar correction user. Compared with the correction data that can be called up in medical institutions in the past, this software can immediately log in and check the correction record on the smart phone. Like quick access to analytical reference effects. Using these two development system equipment, in the children's arch correction experiment, the analysis results show that the child's arch correction should be timely.

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43

Bertani, Michel Christian. "Differences of foot arch index and plantar pressure in elderly people during standing: considering gender, age and foot dominance." Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/77831.

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Bertani, Michel Christian. "Differences of foot arch index and plantar pressure in elderly people during standing: considering gender, age and foot dominance." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/77831.

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45

Tsai, Yue-Hua, and 蔡岳華. "The Effects of Arch-Support Insole on Balance and Gait Plantar Pressure Distribution in Pregnant Women During Third Trimester." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/nxdw9t.

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碩士
國立陽明大學
物理治療暨輔助科技學系
106
Pregnant women are suffered from low back pain, higher plantar pressure and fall due to rapid weight gain, change of center of gravity and change of musculoskeletal system, especially in third trimester. Foot arch are regarded a main structure of foot to absorb shock and keep balance. When foot arch height become lower, it may cause posture instability and abnormal distribution of planter pressure. If they ignore this issue, the problems will become more and more heavily. A foot arch-support insole could resist depression of foot arch and provide adequate stability to help ankle motion. Thus the purpose of this study was to investigate the efficacy of arch-support design insoles on balance and gait plantar pressure in pregnant women during third trimester. Forty women in third trimester of pregnancy with flatfoot were recruited in this study. They were randomly assigned to arch-support group (experimental group) and normal design group (control group). Both groups were accepted collection of demographic data, static balance test, Times Up and Go test, plantar pressure test in walking and pain scale questionnaire. All tests included non-insole and wearing insole situation. The measured data analyzed by two-way mixed Analysis of variance. The SPSS 24.0 was used for statistical analysis and p value of 0.05 was considered to be significant. Result showed the experiment group had significantly lower COP excursion in M-L direction when eye-closed (p=0.009), plantar pressure in first toe (p=0.005) and medial side of middle foot (p=0.041) between pre-test and post-test. The low back pain scale was significantly decreased in experiment group (p=0.041).Control group had no any difference between pre-test and post-test. The women in Third Trimester of Pregnancy with arch-support insoles could help static balance in the darkness, decrease abnormal plantar pressure and reduce low back pain.

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46

Kao, Chiao-Yi, and 高巧宜. "The function of selected lower limb muscles in arch support and center of pressure shifting during stance phase of walking." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/73632564300199481452.

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碩士
國立陽明大學
物理治療暨輔助科技學系
99
Background and purpose: Flexible flatfoot is commonly observed in young children. It is a condition when the medial longitudinal arch of the foot collapses in weight bearing and restores after removing the body weight. The condition is made worse by excessive loose soft tissue in the foot and is linked to various lower extremity injuries, such as patellofemoral pain syndrome, medial tibial stress syndrome and plantar fasciitis. Subjects with flexible flatfoot are usually prescribed exercises for strengthening selected lower limb muscles in order to reduce the risk of getting injury. However, the influence of lower limb muscles, especially the foot intrinsics, on the foot arch support is still unclear. Besides, differences of the center of pressure (COP) excursion between subjects with normal arch and flexible flatfoot were found in the past studies. However, it is unclear if the difference in COP excursion is associated with differential activation of selected lower extremity muscles. The purposes of our study are: (1) to investigate the function of selected lower limb muscles in arch support, and (2) to explore the association between the muscle activation of selected muscles and the displacement of COP during walking. Methods: Twenty flexible-flatfooted subjects and fifteen normal-arched subjects were recruited. The arch height, range of motion of ankle and foot, muscle strength of selected lower extremity muscles were measured in both groups. Then we collected activation of tibialis anterior, preoneus longus and hallucis abductor with surface electromyography and recorded the path of COP while the subjects were walking on a pressure mat system. Statistical Analysis: Independent t test was used to analyze group differences in the ROM and muscle strength. Analysis of variance with repeated measures was used to analyze the differences between the two groups in muscle activation of each period of the stance phase. Then we calculated Pearson's correlation coefficient to estimate the association between muscle strength, COP displacement, muscle activation and the severity of flatfoot. Results: Subjects with flexible flatfoot is stronger in hallucal abductor/flexor groups than the normal-arched subjects. The muscle activation of abductor hallucis in the terminal stance is significantly higher in subjects with flatfoot. The mediolateral displacement of COP during walking is smaller in flatfooted subjects. There are positive correlations between the severity of flatfoot, strength of hallucal abductor/flexor groups and the activation of abductor hallucis during terminal stance (r=0.43-0.49). There is a weak negative correlation between the mediolateral displacement of COP and severity of flatfoot (r=-0.35). Conclusions: The posture of foot might influence selected muscle activation and COP excursion during gait. The hallucal abductor/flexor groups are stronger and the abductor hallucis muscle is more active in the terminal stance in our subjects with mild flexible flatfoot; this may be explained by overloading the muscle to aid push-off and propulsion of the body weight in these individuals. Additionally, narrower mediolateral COP span, which was weakly negatively correlated to the activation of abductor hallucis, was found in subjects with flatfoot during walking. Clinical Relevance: Abductor hallucis is assicated with COP excursion during gait, and may be highly recruited in subjects with mild flexible flatfoot. These subjects may benefit from training programs to reduce the risk of fatiguing this muscle.

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47

Charles, James Arthur. "An investigation into ankle joint dorsiflexion, musculoskeletal injury, arch height, foot pressure and diabetes in association with poor foot health outcomes in an Aboriginal population." Thesis, 2017. http://hdl.handle.net/1959.13/1353477.

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Research Doctorate - Doctor of Philosophy (PhD)
Aboriginal and Torres Strait Islander Peoples suffer from high rates of chronic disease, including peripheral vascular disease, and diabetes, and the associated increases in morbidity and mortality has an enormous impact on both life span and quality of life. Foot health in Aboriginal and Torres Strait Islander Peoples is widely accepted to be poor. In those with diabetes there is a high incidence of neuropathy, foot ulceration, infection and amputation. However, there is little available literature investigating the nature and extent of foot disease in Aboriginal and Torres Strait Islander Peoples, particularly in those with diabetes, or how this can be effectively managed. Anecdotal evidence suggests high rates of restricted ankle joint dorsiflexion (ankle equinus) may exist in the Aboriginal and Torres Strait Islander population and this may be a significant contributing factor to the development of diabetic foot complications including pressure ulcerations. This research addresses the hypotheses that: ; Chronic disease and lifestyle factors significantly contribute to foot complications in Aboriginal and Torres Strait Islander Peoples. ; Culturally appropriate inclusive health promotion can improve foot health outcomes and support healthy lifestyle choices in an Aboriginal and Torres Strait Islander community. ; High prevalence of ankle equinus significantly contributes to elevated plantar pressures in Aboriginal and Torres Strait Islander Peoples with and without diabetes, which may be a significant factor contributing to poor foot health. Firstly, a literature review was conducted to establish current risk factors and risk markers for poor foot health in Aboriginal and Torres Strait Islander Peoples. Little data were found relating specifically to Aboriginal foot health, however high prevalence of chronic disease associated with foot complications including diabetes, neuropathy and peripheral vascular disease were evident. Lifestyle factors associated with increased risk of chronic disease, including smoking and obesity were also found to be highly prevalent, particularly in women. No literature investigating the role of lower limb structure or biomechanical function in development of foot complications was found. Secondly, a review of the literature to determine a reliable method of measuring ankle joint range of motion was conducted. This review showed significant inconsistency in the literature in relation to the definition and diagnosis of ankle equinus, and a lack of standardised method for clinical assessment. Based on these findings a device for accurately measuring ankle equinus was developed, (the Charles device) which was established to have excellent inter- and intra-tester reliability. Thirdly, a culturally appropriate health promotion program for improving foot health, reducing injury and increasing healthy lifestyle choices was developed for the local Worimi Aboriginal community in Forster/Tuncurry, New South Wales. Evaluation of this program demonstrated that it was effective in improving healthy lifestyle knowledge, behaviours and reducing risk of lower limb injury. These findings suggest appropriate health promotion may be successful in reducing risk of foot complications in Aboriginal and Torres Strait Islander People. Subsequently two cross-sectional cohort studies, one in Aboriginal and Torres Strait Islander People with diabetes and one in those without diabetes, were undertaken to test the hypothesis that restricted ankle joint dorsiflexion increases plantar pressures under the forefoot. High prevalence of isolated gastrocnemius equinus was found in both cohorts. Reducing ankle joint range of dorsiflexion was found to be significantly associated with higher peak pressures under the forefoot, and to be an independent predictor of increasing pressure-time integral under the forefoot in both populations. These results, limited by cross-sectional design, suggest ankle equinus may play a key role in the development of pressure-related forefoot complications in Aboriginal and Torres Strait Islander Peoples. Finally, as an appendix to this thesis, visual assessment of Aboriginal skeletal remains of the foot, of a small number of Kaurna People and 21,000 years old footprints of the Paakantji, Ngiyampaa and the Mutthi Mutthi Aboriginal People in Lake Mungo was undertaken. These were examined for arch height, indications of biomechanical characteristics of the foot and ankle and overt osseous pathology. Many of the ancient footprint showed signs of a high arch foot type similar to modern day Aboriginal footprints. In addition, bony spurring on the calcanei on a number of specimens was consistent with possible restriction in ankle dorsiflexion, suggesting ankle equinus may be an evolutionary trait in this population (Appendix 7).

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48

Yuan, Ing-Sen, and 袁應森. "Nonlinear hydrodynamic pressures on rigid arch dams." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/28074596021980800825.

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碩士
國立成功大學
水利及海洋工程學系
82
This paper extends Hung and Chen's （1990） two dimensional numerical model to establish a three dimensional numerical model and discusses the hydrodynamic pressure on rigid arch dam faces during earthquakes. The nonlinear effects of free surface varitation and convective acceleration are included in the analysis. Different kinds of dam-reservoir systems are studied here and their corresponding geometric effects on hydrodynamic pressures are also discussed. Besides, the relationship between the linear hydrodynamic force coefficients and the intensity of the ground acceleration are studied and a simple empirical formula can be given.

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49

Dunlop, Erik Christopher. "Controls on Gas Production from Permian Ultra-deep Coal Seams of the Cooper Basin: Expanding Reservoir Boundary Theory." Thesis, 2019. http://hdl.handle.net/2440/123421.

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This thesis reveals atypical dynamic reservoir behaviour within Cooper Basin ultra-deep coal seams during gas production that calls for a paradigm shift in gas extraction technology, diametrically opposed to the evolutionary path of current drilling, wellbore completion, and reservoir stimulation practices. An anomalous geomechanical reservoir boundary condition is detected that is, by definition, mostly restricted to ultra-deep coal seams. The discovery has resulted in the formulation of a new coal seam reservoir concept - “Expanding Reservoir Boundary Theory”. Ultra-deep Permian coal seams of the Cooper Basin in central Australia represent a nascent thermogenic source rock reservoir play. Proof-of-concept gas flow occurred in 2007. The vast (100+ Tscf) potential resource is comparable in commercial significance, and technical challenge, to the shale gas plays of North America. As with shale, full-cycle, standalone commercial gas production from Cooper Basin ultra-deep coal seams requires a large, complex, permeable “stimulated reservoir volume” (SRV) domain having high fracture / fabric face surface area for gas desorption. This goal has not yet been achieved after 13 years of trials because, owing to the bipolar combination of coal-like geomechanical properties and shale-like reservoir properties, these poorly cleated, inertinitic coal seams exhibit “hybrid” characteristics. This is problematic for achieving effective reservoir stimulation, and poses the greatest immediate challenge. Stimulation techniques adopted from other play types are incompatible with the highly unfavourable combination of nanoDarcy-scale permeability, “ductility”, and high stress. The Cooper Basin Deep Coal Gas (CBDCG) Play commences 6,000 feet (1,830 metres) below the “commercial permeability depth limit” for most shallow coal seam gas (CSG) reservoirs but this does not reduce gas flow potential. Shale gas industry technologies have, in principle, eliminated the requirement for naturally occurring coal fabric permeability. Optimum reservoir conditions occur at depths beyond 9,000 feet (2,740 metres), driven by very low water saturation, high gas content, gas oversaturation, overpressure, rigid host rock strata, and high deviatoric stress. The limited literature does not yet adequately characterise the physical response of ultra-deep coal seams, and the surrounding host rock strata, to production pressure drawdown. It remains to be established how artificial fracture and coal fabric aperture width change as a consequence of the dynamic, diametric competition between gas desorption-induced coal matrix shrinkage and the omnipresent tendency for reservoir compaction caused by increasing production pressure drawdown-induced effective stress. This technical impasse, inhibiting commercialisation, is addressed by analysing the atypical flowback behaviour of hydraulically fracture stimulated coal seams within a dedicated vertical wellbore at 9,500 feet (2,900 metres). High-resolution, non-classical flowback analysis is performed on the pure dataset of Australia’s first ultra-deep coal gas well. Wellhead and fracture network pressures are recorded continuously for 8 1/2 years, at a 10-minute sample interval, while flowing to atmosphere. Natural flowback behaviour is analogous to that of a mechanical gas plunger artificial lift system. A low but gradually increasing quasi-steady state base gas flow, free of produced formation water, is overprinted by a non-steady state, cyclical pressure signature that is diagnostic of dynamic reservoir behaviour during gas production. A total of 114 high-rate, “geyser-like” gas surge events, gradually increasing in duration from 2 hours to 2 weeks, and in reservoir equivalent volume from 360 to 20,000 rcf (10 to 570 rcm), suggest the gas headspace compartment of a “down-hole void space domain” is steadily increasing in size. The gas surge events result from intermittent release of fracture network gas, hydrostatically compressed by flowback fluid slowly accumulating within the wellbore. A production “history match” for the gas surge event pressure profile is obtained by designing, fabricating, operating, and data logging a computer-controlled hydraulic apparatus within The University of Adelaide’s experimental wellbore, at a depth of 230 feet (70 metres). This physically simulates open-ended flowing manometer-like hydrodynamic behaviour of the wellbore-reservoir system. A postulated geological trigger mechanism for surge initiation is tested and validated; “wellbore hydrostatic back-pressure and reservoir stress-dependent leak-off”. Time-lapse pressure transient analysis (PTA) is performed on three extended wellbore pressure build-up tests, lasting 157, 259, and 295 days respectively. Increasing permeability is recognised within coal fabric surrounding the initial fracture network SRV domain. Time-lapse rate transient analysis (RTA) performed on the first two subsequent wellbore pressure “blow-down to atmosphere” (BDTA) gas flow rate decline profiles indicates that hydraulic fracture flow conductivity increased during the intervening 327-day flowback period. Interpreted dilation of hydraulic fracture apertures is supported by a 60% increase in the initial BDTA gas flow rates, from 7.5 to 12.0 MMscfd (212.4 to 340.0 Mscmd). Cooper Basin ultra-deep coal gas reservoirs behave differently to other deep, thermogenic source rock reservoirs, and require a paradigm shift in reservoir stimulation technology that does not rely exclusively upon hydraulic fracture stimulation and the “brittleness factor”. Pressure arching may fill this role by neutralising the omnipresent tendency for reservoir compaction caused by increasing production pressure drawdown-induced effective stress. The combined, mutually sustaining actions of desorption-induced coal matrix shrinkage and sympathetic pressure arch “stress shield” evolution generate an “expanding reservoir boundary and decreasing confining stress” condition that allows producing ultra-deep coal seams, and adjacent strata indirectly (which may include other reservoir types), to progressively de-stress and “self-fracture” in an overall state of endogenous tensile failure. As with underground coal mine excavations, pressure arching will deflect maximum stress vectors around the dilating “dispersed coal fabric void space” domain of a growing fracture network SRV domain that has developed reduced bulk structural integrity, and reduced bulk compressive strength, compared to the surrounding native coal seam and host rock strata. Size and effectiveness of pressure arching increases with depth. Cooper Basin ultra-deep coal seams, and adjacent “non-coal” reservoirs indirectly, may be effectively stimulated to flow gas on a large scale by harnessing this self-perpetuating, depth-resistant mechanism for creating coal fracture / fabric permeability and surface area for gas desorption. They may be induced to pervasively “shatter”, or “self-fracture”, naturally during gas production, independent of the lack of “brittleness”, analogous to the manner in which shrinkage crack networks slowly form, in a state of intrinsic, endogenous tension, within desiccating clay-rich surface sediment. Full-cycle, standalone commercial gas production is considered likely to occur when “Expanding Reservoir Boundary Theory” is applied, so as to replicate the very large, complex fracture network SRV domain of commercial shale gas reservoirs.
Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2020

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50

SU, ZHUO-JIN, and 蘇灼謹. "Arth pressure computations by self generating failure planes." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/93344989561985219601.

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