441 research outputs found
Comparison between cohesive zone models and a coupled criterion for prediction of edge debonding
International audienceThe onset of edge debonding within a bonded specimen submitted to bending is modeled with two numerical approaches: the coupled criterion and the cohesive zone model. The comparison of the results obtained with the both approaches evidences that (i) the prediction of edge debonding strongly depends on the shape of the cohesive law and (ii) the trapezoidal cohesive law is the most relevant model to predict the edge debonding as compared with the coupled criterion
Mode II loading in sharp V-notched components: a comparison among some recent criteria for brittle fracture assessment
Abstract Different criteria are available in the literature to assess the fracture behaviour of sharp V-notches. A typical and well-known criterion is based on the application of the notch stress intensity factors (NSIFs), which are able to quantify the intensity of the stress fields ahead of the notch tip. This work considers two recent energy-based criteria applied here to sharp V-notches. The first criterion is based on the averaged value of the strain energy density (SED), while the second one called Finite Fracture Mechanics (FFM) criterion is available under two different formulations: that by Leguillon et al. and that by Carpinteri et al. Considering the averaged SED criterion, a new expression for estimating the control radius R c under pure Mode II loading is proposed and compared with the sound expression valid under pure Mode I loading. With reference to pure Mode II loading the critical NSIF at failure can be expressed as a function of the V-notch opening angle. By adopting the three criteria considered here the expressions for the NSIFs are derived and compared. After all, the approaches are employed considering sharp V-notched brittle components under in-plane shear loading, in order to investigate the capability of each approach for the fracture assessment. With this aim a bulk of experimental data taken from the literature is used for the comparison
The formalization of a leadership workshop
Includes bibliographical references.The seminar is intended to be an interesting and challenging leadership workshop for the undergraduate management majors of Northern Illinois University. Our goal is to better prepare the students for the real-life business environment by becoming aware of their own style of leadership and the style of other, well-known leaders. The workshop examines the concepts and practices of leadership and pays particular attention to contemporary research findings about leadership, the practice of leadership, and leadership skill development. If the feedback from the first workshop is positive, I would like to see the seminar be expanded so it is available to every business major. All business students would benefit from possessing leadership skills.B.S. (Bachelor of Science
A Finite Fracture Approach for Determining the Fracture Onset of a Brazed SiC Specimen
AbstractThe failure initiation of a brazed sample made of silicon carbide substrates and submitted to bending is analyzed with the help of a criterion which combines a maximum incremental energy release rate and a maximum tensile stress conditions. Two different modes of cracking are considered to develop in the vicinity of the free edge between the brazed layer and the ceramic substrate: edge debonding and substrate cracking. The comparison of the predictions with the experimental results allows estimating the fracture properties of the bonding
Triaxialité et isomèrisme à hauts spins dans les noyaux proches de la fermeture de couche N = 82
L'existence de noyaux triaxiaux a fait l'objet d'un débat de longue date. La possibilité de la triaxialité mole et rigide a été proposée très tôt, et de nombreuses études théoriques et expérimentales ont été consacrées à ce phénomène intrigant. Plus récemment, deux marqueurs uniques de la triaxialité dans les noyaux ont été intensivement étudiés : le mouvement d'oscillation de l'axe de rotation (wobbling) et la chiralité dynamique. Ces types exotiques de mouvement ont été observées dans des régions spécifiques du tableau nucléaire : le mouvement d'oscillation dans les noyaux de Lu impair-pair avec A ~ 160, la chiralité principalement dans les noyaux impair-impair et pair-impair avec A ~ 130. Nous avons récemment étudié les noyaux de Nd à très hauts spins et identifié plusieurs bandes, qui ont été interprétées comme la manifestation de divers types de mouvement collectif : rotation suivant un axe incliné, rotation suivant les axes longs et courts, mouvement de wobbling et bandes chirales. Un autre phénomène révélé par nos résultats récents sur les noyaux de Nd avec seulement quelques trous neutroniques par rapport à la fermeture de couche N = 82, est la coexistence de forme. En effet, ces noyaux sont prévus pour avoir des isomères de hauts spins construis sur une forme sphérique, coexistant avec des bandes triaxiales, ou des formes très voire super-déformées . Ma thèse se compose de deux expériences. Tout d'abord, j'ai préparé, exécuté et analysé une expérience réalisée au Research Center of Nuclear Physics (RCNP) de l' Université d'Osaka . Cette expérience visait à étudier les isomères de hauts spins et à développer les schémas de niveaux des noyaux de 135La, 136La et 136Ba. Nous avons utilisé un faisceau radioactif de 17N de 80 MeV créé par la réaction directe de 18O sur une cible 9Be et sélectionné à l'aide d'un spectromètre achromatique. Le faisceau radioactif de 17N bombardait une cible de 124Sn de 20 mg/cm2 d'épaisseur pour produire les noyaux d'intérêt par une réaction de fusion-évaporation. Cette thèse présente les résultats obtenus pour le 135La, qui comprennent la construction et la discussion du schéma de niveau et la mesure de la durée de vie de deux isomères connus. La deuxième partie de la thèse consiste en l'analyse de deux expériences différentes réalisée en utilisant la même combinaison de faisceau-cible 48Ca + 96Zr à une énergie légèrement différentes et deux dispositifs expérimentaux différents, EUROBALL et JUROGAM II + RITU + GREAT, pour étudier les isotopes du néodyme de 138Nd à 141Nd. Mon travail a été axé sur les noyaux pair-pair de 138Nd et 140Nd, avec un accent particulier sur le 140Nd. La multitude de bandes de spin élevé observées dans ce noyau sont discutées dans le cadre du modèle Cranked Nilsson - Strutinsky (CNS) et du modèle Tilted Axis Cranking (TAC). Les bandes de hauts spins observées dans les noyaux de 138-141Nd sont toutes interprétées comme basées sur un minimum d'énergie associé à une déformation triaxiale. Elles représentent donc un fort soutien à l'existence de la forme nucléaire triaxiale stable à hauts spins. L'isomère de haut spin 27 a également été identifié dans le 140Nd qui, combinée avec l'isomère 20+ précédemment connu dans le même noyau va permettre d'extraire pour la première fois une valeur expérimentale de la différence d'énergie entre les orbitales ph11/2 et p(d5/2g7/2) à hauts spins.The existence of triaxial nuclei has been the subject of a long standing debate. The possibility of soft and rigid triaxiality has been proposed very early, and many theoretical and experimental studies have been devoted to this intriguing phenomenon since then. More recently two unique fingerprints of triaxiality in nuclei have been intensively studied : the wobbling motion and the dynamic chirality. These exotic types of motion were observed in specific regions of the nuclear chart : the wobbling motion in the odd-even Lu nuclei with A 160, the chirality primarily in the odd-odd and odd-even nuclei with A 130 nuclei. We have recently studied the Nd nuclei up to very high spins and identified several bands, which were interpreted as the manifestation of various types of collective motion : tilted axis rotation, principal axis rotation along the short and long axes, wobbling motion and chiral bands. Another phenomenon revealed by our recent results on the Nd nuclei with neutron numbers just below the N=82 shell closure, is the shape coexistence. In fact, these nuclei are predicted to have high-spin seniority isomers built on a spherical shape, coexisting with bands built on either triaxial, highly or even superdeformed shapes.My PhD consists of two experiments. Firstly I have prepared, performed and analysed an experiment realized at the Research Center of Nuclear Physics (RCNP) of the Osaka University. This experiment was performed to study the isomeric states and to develop the level schemes of the 135La, 136La and 136Ba nuclei. We have used a radioactive 17N beam of 80 MeV created by the stripping reaction of 18O on a 9Be target and selected using an achromatic spectrometer. The 17N radioactive beam bombarded a 20 mg/cm2 124Sn target to produce the nuclei of interest by a fusion-evaporation reaction. The present thesis presents the results obtained for 135La, which include the construction and discussion of the level scheme and the measurement of the lifetime of two known isomers. The second part of the thesis consists in the analysis of two different experiments performed using the same beam-target combination 48Ca + 96Zr at slightly different beam energies and two different settups, EUROBALL and JUROGAM II + RITU + GREAT, to study the neodymium isotopes from 138Nd to 141Nd. My work was focused on the even-even 138Nd and 140Nd nuclei, with special emphasis on 140Nd, which is discussed in the present thesis. The multitude of high-spin bands observed in this nucleus are discussed in the framework of Cranked Nilsson-Strutinsky (CNS) and Tilted Axis Cranking (TAC) models. The observed high-spin bands in 138 141Nd which are consistently interpreted as based on an energy minimum at triaxial deformation, represent a strong support for the existence of stable triaxial nuclear shapes at high spins. A 27 high-spin isomer has also been identified in 140Nd, which combined with the previous known 20+ isomer in the same nucleus allow to extract for the first time an experimental value for the energy difference between the ph11/2 and p(d5/2g7/2) orbitals at high spins.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF
Prise en compte des contraintes résiduelles dans un critère de rupture fragile
On étudie la fissuration, sous chargement mécanique et thermique, d'un joint de colle reliant deux substrats d'aluminium. Les extrémités des interfaces entre le joint et les substrats constituent des points de concentration de contraintes pour la structure, caractérisés par des champs élastiques singuliers. Sous certaines hypothèses sur le comportement des substrats d'aluminium, l'analyse est menée sur la couche d'adhésif. Un critère d'amorçage déjà existant est étendu aux chargements thermo-mécaniques et permet de prédire la contrainte à rupture. Les résultats théoriques sont comparés à des mesures expérimentales disponibles dans la littérature. Nos prédictions sont en accord satisfaisant avec l'expérience mais il est clair qu'une meilleure connaissance des conditions d'élaboration, donc des contraintes résiduelles, permettrait de mieux rendre compte des résultats expérimentaux
Trends in computerized provider order entry: 20-year bibliometric overview
BackgroundDrug-related problems (DRPs) can lead to serious health issues and have significant economic impacts on healthcare systems. One solution to address this issue is the use of computerized physician order entry systems (CPOE), which can help prevent DRPs by reducing the risk of medication errors.ObjectiveThe purpose of this study is to provide an analysis on scientific production of the past 20 years in order to describe trends in academic publishing on CPOE and to identify the major topics as well as the predominant actors (journals, countries) involved in this field.MethodsA PubMed search was carried out to extract articles related to computerized provider order entry during the period January 1st 2003– December 31st 2022 using a specific query. Data were downloaded from PubMed in Extensible Markup Language (XML) and were processed through a dedicated parser.ResultsA total of 2,946 articles were retrieved among 623 journals. One third of these articles were published in eight journals. Publications grew strongly from 2002 to 2006, with a dip in 2008 followed by an increase again in 2009. After 2009, there follows a decreasing until 2022.The most producing countries are the USA with 51.39% of the publication over the period by France (3.80%), and Canada (3.77%). About disciplines, the top 3 is: “medical informatics” (21.62% of articles), “pharmacy” (19.04%), and “pediatrics” (6.56%).DiscussionThis study provides an overview of publication trends related to CPOE, which exhibited a significant increase in the first decade of the 21st century followed by a decline after 2009. Possible reasons for this decline include the emergence of digital health tools beyond CPOE, as well as healthcare professionals experiencing alert fatigue of the current system.ConclusionFuture research should focus on analyzing publication trends in the field of medical informatics and decision-making tools to identify other areas of interest that may have surpassed the development of CPOE
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