No description available.

M.Tech. (Homoeopathy) / Chronic tension-type headaches (CTTHs) affect 30-40% of the population and account for a number of absences from, and decreased performances at, work and school as well as recreational activities. CTTHs typically occur at least 15 times a month or at least every second day, and present as an achey or tight sensation that is felt around the head. The pain may last from 30 minutes to several days and varies in intensity. Conventional treatment is palliative, consisting of analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs), which may produce adverse effects and analgesic rebound headaches. Lacticum acidum 30CH is a homoeopathic remedy that has been shown to have potential benefits in the treatment of CTTHs. Homaccords are the preparation of one remedy in multiple increasing potencies in a single vehicle. There has been no research done to date on Lacticum acidum Homaccord in the treatment of CTTHs. The aim of this study was to determine the efficacy of Lacticum acidum Homaccord in the treatment of CTTHs, using the modified Headache Diary and the Headache Disability Inventory. The study was a randomised, double-blind, placebo-controlled matched pair study which took place at the Homoeopathic Health Centre at the University of Johannesburg (UJ) Doornfontein campus, over a period of four weeks. A randomised sample of 34 male and female participants between the ages of 18 and 45 years who suffered from CTTHs were recruited by means of purposive sampling via advertisements placed on the UJ campus. At the initial consultation (day 0), prospective participants were requested to sign the Participant Information and Consent Form. The participants were then requested to complete the Screening Questionnaire to assess their eligibility for participating in the study. Participants’ meeting the diagnostic criteria for CTTHs, and those whose symptoms matched at least eight out of the twelve Lacticum acidum headache-related symptoms, were eligible to participate in the study. Participants’ were placed into matched pairs, according to gender and age. Participants in both groups received one 30 mL bottle of their respectively dispensed and labelled medication. On days 1-28 the participant was requested to complete the modified Headache Diary at the end of each day and to take 5 pillules of the medication in the morning and in the evening of each day. The first follow-up visit occurred on day 14; here participants completed the Headache Disability Inventory; the completed headache diaries were exchanged with new ones, a physical examination with vital signs was conducted and an additional bottle of medication was given. The second and final follow-up vi visit occurred on day 28, where the participant completed the Headache Disability Inventory, and a physical examination with vital signs was conducted. The average duration (time), intensity, frequency of headaches, and medication use was recorded on a daily basis and the level of perceived disability from CTTHs was measured weekly. This was conducted by completing the modified Headache Diary and the Headache Disability Inventory respectively. The data from the study was evaluated and analysed using frequencies and descriptive tests, cross tabulations, the Shapiro Wilk test, the Mann-Whitney test, and the Friedman and Wilcoxon signed ranks tests ...

A dissertation submitted in partial fulfillment of the requirements for the Masters Diploma in Technology: Chiropractic at Natal Technikon, 1994. / The effectiveness of chiropractic management of tension-type headache was evaluated in a single blind, randomised, placebo controlled tr ial us ing a pat ient populat ion of thirty (30) individuals who were suffering from tension-type headache / M

The surface tension of solid commercially pure nickel was determined by the force measurement technique using fine wires as proposed by Udin, Shaler, and Wulff. Grain boundary measurements were also made on the same metal. After finding experimentally that tests in a vacuum of approximately 5 x 10⁻⁵ mm Hg were unsuccessful because of the high power vapour pressure of nickel at high temperatures, similar tests were made in helium and argon atmospheres, the pressure being kept constant at 760 mm Hg during the experiments. The average surface tension of nickel in argon was found to be 2220 ± 300 dynes per centimeter for a temperature range from 1370°C to 1390°C. The relative grain boundary energy of solid nickel was determined by measuring the dihedral grain boundary groove angles of thermally etched nickel. The interferometric method developed by Hilliard and Harrold was used for this purpose. An average value of 161 degrees was found for the dihedral angle. The grain boundary energy was calculated to be 740± 300 dynes per centimeter. Examination of thermally etched nickel surfaces was inconclusive with respect to physical evidence for dislocation. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

No description available.

Ce travail décrit une nouvelle topologie d'alimentation qui apporte des bénéfices aux dispositifs portables et aux composants électroniques à faible consommation. À l'autre extrémité du spectre, il serait également applicable aux systèmes à tension de bus plus élevée, tels que les panneaux solaires et les véhicules électriques, qui doivent décomposer des tensions plus élevées en domaines utilisables. La nouvelle topologie, que nous avons nommée Waterfall regulator, est décrite dans le présent travail et nommée ainsi pour ses caractéristiques saillantes rappelant une chute en cascade. Ce dispositif ouvre de nouvelles perspectives pour les systèmes à très basse consommation, basse tension et courant faible. Le mode de fonctionnement consiste à diviser une source d'alimentation brute en plusieurs domaines de tension, qui peuvent ensuite être utilisés pour alimenter les éléments individuels d'un système ou plusieurs unités indépendantes. Nous décrivons ici le premier rapport sur la réussite de la version de recyclage de l'énergie de ce nouveau système. Le dispositif se caractérise par une série de régulateurs de tension à faible chute et de circuits de déversement de courant (pass MOSFET). Le régulateur partage le courant qui traverse sa charge respective et complète le courant du stade suivant par un déversoir de courant, selon les besoins. Le contrôle s'effectue via une architecture de contrôle en cascade et peut être étendu à des périphériques d'ordre supérieur. / This work described a new power supply topology that benefits portable device and low power electronics. At the other end of the spectrum, it is also applicable to higher bus voltage systems like solar panels and electric vehicles that must split higher voltages into usable domains. The new topology, which we named waterfall regulator, is describe herein and named as such for its salient features reminiscent of a waterfall. It opens up a new realm of possibilities for supra low power, low voltage and low current systems. The mode of operation consists of splitting a raw supply source into smaller voltage domains which can then be used for powering individual element of a system or powering multiple independent units. We describe here the first report of successful energy recycling version of this novel system. The devices are composed of a series of low dropout voltage regulators and current spillways circuits (pass MOSFET). The regulators share current passing thought their respective load and supplement current through a current spillway as required. Control is achieved through a cascade architecture and can be scaled up to higher order devices.

Cette thèse porte sur la modélisation de l'ébullition qui joue un rôle important dans les vitessesde refroidissement des pièces, elle possède un volet numérique et un volet expérimental. Lessimulations et les expériences envisagées se situent à deux échelles. A l'échelle d'une ou quelquesbulles de vapeur, il s'agit de faire des simulations multiphasiques très précises en prenant encompte, la tension de surface, les calculs directs d'écoulement à grand nombre de Reynolds, etrendant compte du détachement et de la coalescences des bulles. Des observations expérimentalessont réalisées à la même échelle en contrôlant en surface la nucléation d'une bulle de vapeur àl'aide d'une caméra rapide. Des mesures de champs de vitesse par PIV et de température par twocolor LIF thermometry sont réalisées dans les mêmes conditions. Ceci a permit de confronter lacroissance, la dynamique et les formes des bulles observées et calculés. Les techniques numériquesles plus avancées sont utilisées : Eléments finis stabilisé VMS, level set, adaptation anisotropeet calcul intensif. Les modéles numériques proposés dans cette thèse permettent de passer àl'échelle macroscopique des pièces industrielles en considérant un film de vapeur (ou une phasede mélange liquide vapeur). L'enjeu supplémentaire étant de modéliser la turbulence induite parl'ébullition dans une approche de type CFD. / This thesis focuses on the modelling of boiling that plays an important role on the coolingand heat treatment in quenching processes, it has two components: numerical simulations andexperimental measurements. Both simulations and experiments are envisaged for two scales. Thefirst one concerns small scales: the scale of one or few bubbles. In this case, the focus is put onvery precise numerical simulations for multiphase flows taking into account the surface tension,the direct computations of flows at high Reynolds number, and on reflecting the detachmentand coalescence of bubbles. On that same scale, experimental observations are performed tocontrol, in the volume or at surface, the nucleation of a vapour bubble using a high speedcamera. Measurements of velocity fields by PIV and the temperature by PLIF are realizedunder the same conditions. This will allow us to compare the growth dynamics and shapesof bubbles observed and calculated. Advanced numerical methods are used to fulfil this task:VMS stabilized finite elements, level set, anisotropic adaptation and parallel computing. Thenumerical models proposed in this work are extended and also used to deal with macroscopicscales: at the level of industrial parts considering the vapour films (or a phase of liquid vapourmixture). The additional challenge resides in the modelling of turbulence induced by boiling ina CFD approach.

The scope of this thesis is micromanipulation in liquid media. This scientific field aims at understanding the relevant phenomena existing during the manipulation in a liquid of microcomponents having a size between $1,micrometer$ and a few millimeters. This work focuses on the study of surface tension forces in immersed media, because they have favorable scaling effect. The main idea is to use gas bubbles as actuation mean in a liquid, and requires to study the mechanical properties of these bubbles. The originality of the approach is the combination of two effects: surface tension and gas compressibility. The first step was the study of an efficient mean to generate a single bubble of predefined size. After a detailed review, it appeared that volume controlled bubble generation was a promising method. We have then developed a model to predict the size of a bubble, and emphasized the possible existence of a growing instability. An analytic dimensionless study allowed to define a criterion to predict the existence of this instability. The second step aimed at the mechanical characterization in quasi static equilibrium of a gas bubble caught between two solids. The purpose is to predict the force generated by the bubble, together with its stiffness. The model implemented allowed to infer interesting properties, notably a high compliance whose value is controllable by fluidic parameters. This compliance property being very important during micromanipulation, a demonstrator making use of gas bubbles has been designed and manufactured. It consists in a compliant microtable actuated by three bubbles. This work opens the way to new actuation or sensing means, using the transduction between fluidic and mechanic energy operated by a capillary bridge. / Cette thèse a pour contexte la micromanipulation en milieu liquide. Cette thématique scientifique vise à comprendre les phénomènes qui interviennent lors de la manipulation dans un liquide de microcomposants, dont la taille peut varier entre $1,micrometer$ et quelques millimètres. Les travaux de cette thèse se sont focalisés sur l'étude des forces de tension de surface en milieu immergé, car elles bénéficient d'effets d'échelle favorables. L'idée poursuivie est d'utiliser des bulles de gaz comme un moyen d'actionnement dans les milieux liquides, et nécessite d'étudier les propriétés mécaniques de ces bulles. L'originalité de l'approche repose sur la combinaison de deux effets : la tension de surface et la compressibilité du gaz. La première étape a été l'étude d'un moyen efficace pour générer une unique bulle de gaz de taille voulue. Après une analyse exhaustive, il est apparu que la génération de bulle par le contrôle en volume était une méthode prometteuse. Nous avons alors développé un modèle permettant de prédire la taille d'une bulle, et mis en évidence la possible existence d'une instabilité de la croissance de ces bulles. Une étude analytique adimensionnelle nous a permis de définir un critère pour prédire l'existence ou non de cette instabilité. La seconde étape a porté sur la caractérisation mécanique en régime quasi statique d'une bulle de gaz en contact avec deux solides. Le but étant de prédire la force générée par une bulle de gaz sur les solides ainsi que sa raideur. Le modèle implémenté a permis de déduire des propriétés intéressantes des bulles de gaz, notamment une grande compliance dont la valeur peut être contrôlée par des paramètres fluidiques. Cette propriété de compliance étant très recherchée en micromanipulation, un démonstrateur exploitant les bulles de gaz a été conçu. Il s'agit d'une microtable compliante actionnée par trois bulles. Ces travaux ouvrent la voie vers de nouveaux modes d'actionnement ou de capteur utilisant la transduction entre une énergie fluidique et mécanique opérée par un ménisque capillaire.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 6 uppsatser.

Du cerveau à l’os, la rigidité et la composition de la matrice extracellulaire varient énormément et jouent un rôle dans les réponses cellulaires. La rigidité influe également sur la tension de la membrane plasmique, elle-même régulée par le trafic membranaire. Comment la rigidité et la composition du substrat peuvent réguler l'exocytose, qui à son tour régule la tension de la membrane, reste largement inconnu. Ici, j'ai utilisé l’imagerie pHluorin d’évènements uniques d’exocytose de cellules cultivées sur des substrats de rigidité et de composition contrôlée pour explorer la régulation de VAMP2 et VAMP7. J'ai développé un logiciel informatique pour identifier automatiquement les évènements de fusion, permettant une analyse rapide de données. J'ai contribué à l'étude montrant que l’exocytose VAMP7 est régulée par la kinase src, qui phosphoryle VAMP7 dans son domaine Longin (LD) (Burgo et al. JBC 2013). De plus, j’ai trouvé que la rigidité du substrat stimule l’exocytose, en présence de la laminine, de VAMP7, mais pas VAMP7 sans LD ni VAMP2. VAMP7 et VAMP7 sans LD sont par ailleurs également sensibles aux variations de la tension membranaire induites par chocs osmotiques. Enfin, j'ai identifié que LRRK1 est un partenaire du LD, et contrôle le transport rétrograde de VAMP7.Ces approches m’ont permis de révéler un nouveau mécanisme par lequel la rigidité, agissant sur la signalisation des intégrines, contrôle le transport de VAMP7 via LRRK1 et Rab21 (Wang et al. soumis). Ce mécanisme pourrait avoir un large intérêt potentiel pour comprendre la dynamique de la membrane dans des conditions normales et pathologiques, en particulier le cancer / From brain to bones, stiffness and composition of the extracellular matrix vary greatly and play a role in cell responses. Substrate rigidity also impacts plasma membrane tension, which has a close relationship with membrane trafficking. How substrate rigidity and chemistry sensing may regulate exocytosis, which in turn regulates membrane tension, is still largely unknown. Here, I used pHluorin imaging of single vesicle exocytosis in cells cultured on substrates of controlled rigidity and composition to explore the regulation of VAMP2 and VAMP7-mediated exocytosis. I developed a computer software to automatically identify fusion events thus allowing quick analysis of batch data. I contributed to the study showing that VAMP7 exocytosis is regulated by src kinase which phosphorylates VAMP7 in its Longin domain (LD) (Burgo et al. JBC 2013). I further found that VAMP7 but not VAMP7 lacking LD- or VAMP2-mediated secretion was stimulated by substrate stiffness on laminin. VAMP7 and VAMP7 lacking LD were similarly sensitive to osmotic chock-induced membrane tension changes. Finally, i showed that LRRK1, a regulator of egf receptor transport, is a partner of the LD, and controls the retrograde transport of VAMP7. These approaches allowed me to reveal a new mechanism whereby substrate rigidity, by acting on integrin signalling, enhances VAMP7 exocytosis via LRRK1- and Rab21-dependent regulation of its peripheral readily-releasable pool (Wang et al. submitted). This mechanism may have broad potential relevance for plasma membrane dynamics in normal conditions and diseases, particularly cancer