Modèle par éléments discrets pour l’étude du comportement dynamique d’un matériau élastique.

Le comportement mécanique des matériaux est généralement simulé par des approches issues de la mécanique des milieux continus. Cependant, lorsqu’il s’agit de simuler des phénomènes de multi fissurations voir de multi fracturations, les modèles de la mécanique discrète s’avèrent mieux adaptés, car ils prennent en compte naturellement les discontinuités générées par les interfaces. La difficulté est alors de s’assurer qu’une approche par éléments discrets (DEM) permet bien de retrouver le comportement mécanique au sens de la mécanique des milieux continus. Cet article propose une méthodologie permettant, à partir des données connues du matériau à simuler (module de Young, coefficient de Poisson, célérité de propagation des ondes), de quantifier les paramètres « microscopiques » du modèle DEM

A Proposed Model Worship Service Incorporating a Biblical View of the Holiness of God for the Urbandale, Michigan Seventh-day Adventist Church

Task. In view of significant discussions occurring in the Seventh-day Adventist Church concerning the nature and style of worship, it seems appropriate to address the place the concept of the holiness of God should have in worship. A proposed model worship service incorporating a biblical view of the holiness of God, which could be implemented by the Urbandale, Michigan, Seventh-day Adventist Church, was developed. The term model is used in the sense of a pattern to be tried and not a norm to be readily followed. Method. Four major components of the worship service were identified and described. It was suggested that the fourth component, namely, a sense of the holiness of God, is neglected in many modern worship services. The ideas of various authors regarding the holiness-of-God concept were reviewed. A strong biblical connection between a sense of the holiness of God and worship, and the distinction between the sacred and the secular was demonstrated. The development of a proposed model worship service resulted from a questionnaire, sermons, and worship committee consultations. Sources. There seems to be limited materials obtainable that address the holiness of God in the context of worship. Some authors give the traditional view while others present a humanistic-secular perspective. A significant source was the Bible usage of the concept of holiness as it pertains to God\u27s nature and worship. The primary source for developing a proposed model worship service came from the Bible, literature review, and the dialogue within the congregation. Conclusions. The apparent infrequent attention given to the centrality of the holiness of God in modern worship services has provided an opportunity to rediscover its meaning and importance, and then to develop ways in which it can be featured more prominently in worshiping God. The congregation where this model could be gradually implemented has begun to awaken to a new understanding of biblical worship

AN ANALYSIS OF RESISTANCE SPOT WELD QUALITY BASED ON ACOUSTIC AND ELECTRICAL SIGNATURES

The union of a set of materials by way of Resistance Spot Welding is designed so that once fused together, a substantial amount of intentional, external force must be applied to separate the contents. Therefore, Resistance Spot Welding is often the preferred fusion method in high-volume manufacturing processes. The result of Resistance Spot Welding however is the formation of a weld nugget which is not visible to the naked eye. Destructive and/or ultrasonic methods applied off-line must be used to determine the quality of each weld; both inefficient and expensive processes. The following research analyzes the data fed back during resistance spot weld sequences in-line and establishes a correlation between emitted characteristics and the final quality of a spot weld. The two characteristics researched to segregate weld quality are: the electrical sin wave signature and the acoustic sin wave signature produced during the welding sequence. Both features were discovered to have a direct correlation to the final quality of a weld once cured. By measuring and comparing these characteristics at the source, an opportunity is presented to decrease time and potential defects by confirming the quality of each weld in-process and at the source

PhD

dissertationAcute administration of haloperidol to rats causes a marked decrease in the Km of neostriatal tyrosine hydroxylase for the pteridine cofactor, 6MPH(,4), with no change in Vmax. This effect is dependent on the pH of the assay mixture. It occurs at pH 6.5 but not at pH 6.0, the pH optimum for TH. With phosphorylating conditions at pH 6.5, the haloperidol-induced activation is no longer observed, and the kinetics of TH are the same as those from control rats. At pH values of 6.0, 6.3 and 6.5, a significant decrease in Vmax occurs, with increasing pH, while no significant change in Km for the cofactor is observed for TH from control rats. However, when phosphorylating conditions are employed, a marked increase in Km for the cofactor is observed while only a slight decrease in Vmax is seen, with increasing pH, for the control enzyme at the three pH values tested. The kinetic characteristics of neostriatal tyrosine hydroxylase (TH) activity were then determined after rats were given large, repeated doses of methamphetamine. The Vmax of the enzyme was markedly decreased after methamphetamine, but no change in the Km for pteridine cofactors nor for the substrate, tyrosine, was detected. The decrease in Vmax with methamphetaminee was independent of the phosphorylated state of the enzyme. The effect of propranolol in blocking the methamphetamine-induced depression of tryptophan hydroxylase was then investigated. Acute administration of methamphetamine produced a marked decrease in tryptophan hydroxylase activity in all serotonergic nerve terminal regions of rat brain examined. This decrease was antagonized in a regionally selective manner by propranolol. Almost complete blockade occurred in regions that are commonly implicated in schizophrenia, mesolimbic areas, neostriatum, and hypothalamus; whereas in other regions examined, only partial or no blockade occurred. In contrast, haloperidol did not produce a similar antagonism. The results are discussed in the context of the efficacy of large doses of propranolol in some schizophrenic patients

A Master’s Monument: Shakespeare’s Sonnets in the Poetry of W. B. Yeats

This article explores the reception of Shakespeare’s Sonnets by W.B. Yeats. In her recent study Our Secret Discipline: Yeats and Lyric Form (2007), Helen Vendler has stressed the importance of taking the formal structures of W. B. Yeats’ poetry seriously. If her analyses occasionally seem overwrought in all their technical detail, she nevertheless forcefully argues that “technique was never, for Yeats, without conceptual meaning” (153). But the actual conceptual meanings she brings forth are often less than convincing – particularly so in the case of Yeats’ appropriation of the Shakespearean sonnet.publishedVersio