Strain gradient theory based on a new framework of non-local model

A new framework of non-local model for the strain energy density is proposed in this paper. The global strain energy density of the representative volume element is treated as a non-local variable and can be obtained through a special integral of the local strain energy density. The local strain energy density is assumed to be dependent on both the strain and the rotation-gradient. As a result of the non-local model, a new strain gradient theory is derived directly, in which the first and second strain gradients, as well as the triadic and tetradic stress, are introduced in the context of work conjugate. For power law hardening materials, size effects in thin metallic wire torsion and ultra-thin cantilever beam bend are investigated. It is found that the result predicted by the theoretical model is well consistent with the experimental data for the thin wire torsion. On the other hand, the calculation result for the micro-cantilever beam bend clearly shows the size effect.

Implementation of a non-orthogonal model for the finite element simulation of textile composite draping

In the pursuit of producing high quality, low-cost composite aircraft structures, out-of-autoclave manufacturing processes for textile reinforcements are being simulated with increasing accuracy. This paper focuses on the continuum-based, finite element modelling of textile composites as they deform during the draping process. A non-orthogonal constitutive model tracks yarn orientations within a material subroutine developed for Abaqus/Explicit, resulting in the realistic determination of fabric shearing and material draw-in. Supplementary material characterisation was experimentally performed in order to define the tensile and non-linear shear behaviour accurately. The validity of the finite element model has been studied through comparison with similar research in the field and the experimental lay-up of carbon fibre textile reinforcement over a tool with double curvature geometry, showing good agreement.

Teachers’ reflections on non standard students work

One of the tasks of teaching (Ball, Thames, & Phelps, 2008) concerns the work of interpreting student error and evaluating alternative algorithms used by students. Teachers’ abilities to understand nonstandard student work affects their instructional decisions, the explanations they provide in the classroom, the way they guide their students, and how they conduct mathematical discussions. However, their knowledge or their perceptions of the knowledge may not correspond to the actual level of knowledge that will support flexibility and fluency in a mathematics classroom. In this paper, we focus on Norwegian and Portuguese teachers’ reflections when trying to give sense to students’ use of nonstandard subtraction algorithms and of the mathematics imbedded in such. By discussing teachers’ mathematical knowledge associated with these situations and revealed in their reflections, we can perceive the difficulties teachers have in making sense of students’ solutions that differ from those most commonly reached.

Étude des facteurs de perturbation de chambres d’ionisation sous conditions non standard

Durant la dernière décennie, les développements technologiques en radiothérapie ont transformé considérablement les techniques de traitement. Les nouveaux faisceaux non standard améliorent la conformité de la dose aux volumes cibles, mais également complexifient les procédures dosimétriques. Puisque des études récentes ont démontré l’invalidité de ces protocoles actuels avec les faisceaux non standard, un nouveau protocole applicable à la dosimétrie de référence de ces faisceaux est en préparation par l’IAEA-AAPM. Le but premier de cette étude est de caractériser les facteurs responsables des corrections non unitaires en dosimétrie des faisceaux non standard, et ainsi fournir des solutions conceptuelles afin de minimiser l’ordre de grandeur des corrections proposées dans le nouveau formalisme de l’IAEA-AAPM. Le deuxième but de l’étude est de construire des méthodes servant à estimer les incertitudes d’une manière exacte en dosimétrie non standard, et d’évaluer les niveaux d’incertitudes réalistes pouvant être obtenus dans des situations cliniques. Les résultats de l’étude démontrent que de rapporter la dose au volume sensible de la chambre remplie d’eau réduit la correction d’environ la moitié sous de hauts gradients de dose. Une relation théorique entre le facteur de correction de champs non standard idéaux et le facteur de gradient du champ de référence est obtenue. En dosimétrie par film radiochromique, des niveaux d’incertitude de l’ordre de 0.3% sont obtenus par l’application d’une procédure stricte, ce qui démontre un intérêt potentiel pour les mesures de faisceaux non standard. Les résultats suggèrent également que les incertitudes expérimentales des faisceaux non standard doivent être considérées sérieusement, que ce soit durant les procédures quotidiennes de vérification ou durant les procédures de calibration. De plus, ces incertitudes pourraient être un facteur limitatif dans la nouvelle génération de protocoles.

Développement d'un nouveau critère pour déterminer les limites d'utilisation des détecteurs en dosimétrie non standard

Depuis quelques années, il y a un intérêt de la communauté en dosimétrie d'actualiser les protocoles de dosimétrie des faisceaux larges tels que le TG-51 (AAPM) et le TRS-398 (IAEA) aux champs non standard qui requièrent un facteur de correction additionnel. Or, ces facteurs de correction sont difficiles à déterminer précisément dans un temps acceptable. Pour les petits champs, ces facteurs augmentent rapidement avec la taille de champ tandis que pour les champs d'IMRT, les incertitudes de positionnement du détecteur rendent une correction cas par cas impraticable. Dans cette étude, un critère théorique basé sur la fonction de réponse dosimétrique des détecteurs est développé pour déterminer dans quelles situations les dosimètres peuvent être utilisés sans correction. Les réponses de quatre chambres à ionisation, d'une chambre liquide, d'un détecteur au diamant, d'une diode, d'un détecteur à l'alanine et d'un détecteur à scintillation sont caractérisées à 6 MV et 25 MV. Plusieurs stratégies sont également suggérées pour diminuer/éliminer les facteurs de correction telles que de rapporter la dose absorbée à un volume et de modifier les matériaux non sensibles du détecteur pour pallier l'effet de densité massique. Une nouvelle méthode de compensation de la densité basée sur une fonction de perturbation est présentée. Finalement, les résultats démontrent que le détecteur à scintillation peut mesurer les champs non standard utilisés en clinique avec une correction inférieure à 1%.

Logique et Sémantique : Critique d’une interprétation non‐standard de la logique déontique

Ce texte porte sur l’analyse sémantique de la logique déontique. Nous analyserons de façon critique un texte de Schotch (1981) portant sur une interprétation de la logique déontique dans le cadre d’une sémantique non-kripkéenne. Nous laisserons de côté les choix relatifs à la syntaxe de son système afin de se concentrer sur l’analyse sémantique qu’il expose contre la logique déontique et sur celle qu’il propose en retour. Avant de voir le détail de son raisonnement, nous présenterons brièvement quelques notions de logique modale afin de faciliter la compréhension de l’argument de Schotch. Nous présenterons ensuite l’argument de l’auteur contre la logique déontique afin de pouvoir exposer sa solution, ce qui ouvrira la porte à une lecture critique de son analyse.

Simple general method of generating non-oxo, non-amavadine model octacoordinated vanadium(IV) complexes of some tetradentate ONNO chelating ligands from various oxovanadium(IV/V) compounds and structural characterization of one of them

A simple general route of obtaining very stable octacoordinated non-oxovanadium( IV) complexes of the general formula VL2 (where H2L is a tetradentate ONNO donor) is presented. Six such complexes (1-6) are adequately characterized by elemental analysis, mass spectrometry, and various spectroscopic techniques. One of these compounds (1) has been structurally characterized. The molecule has crystallographic 4 symmetry and has a dodecahedral structure existing in a tetragonal space group P4n2. The non-oxo character and VL2 stoichiometry for all of the complexes are established from analytical and mass spectrometric data. In addition, the non-oxo character is clearly indicated by the complete absence of the strong nu(v=o) band in the 925-1025 cm(-1) region, which is a signature of all oxovanadium species. The complexes are quite stable in open air in the solid state and in solution, a phenomenon rarely observed in non-oxovanadium(IV) or bare vanadium(IV) complexes.

Non-standard working time: an international and comparative analysis

This paper uses the large-scale Cranet data to explore the extent of non-standard working time (NSWT) across Europe and to highlight the contrasts and similarities between two different varieties of capitalism (coordinated market economies and liberal market economies). We explore variations in the extent of different forms of NSWT (overtime, shift working and weekend working) within these two different forms of capitalism, controlling for firm size, sector and the extent of employee voice. Overall, there was no strong link between the variety of capitalism and the use of overtime and weekend working though shift working showed a clear distinction between the two varieties of capitalism. Usage of NSWT in some service sectors was particularly high under both forms of capitalism and service sector activities had a particularly marked influence on the use of overtime in liberal market economies. Surprisingly, strong employee voice was associated with greater use of NSWT.

Managing non-standard international experience: evidence from a Finnish company

Purpose – This paper extends the increasing debates about the role of international experience through mechanisms other than standard expatriation packages, in particular through the use of short-term assignments. It explores the different forms of short-term assignments (project work, commuter assignments, virtual international working and development assignments) and the different sets of positive and negative implications these can have for the company and the individuals concerned. The integration-differentiation debate is reflected here as elsewhere in IHRM, with the company moving towards greater centralization and control of its use of these assignments. Design/methodology/approach – Since the research is exploratory, we adopted a qualitative approach to get a more in-depth understanding on the realities the corporations and the assignees are facing. The study was implemented through a single case study setting in which the data were collected by interviewing (n=20) line managers, human resource management (HRM) staff and assignees themselves. In addition corporate documentation and other materials were reviewed. Findings – The present case study provides evidence about the characteristics of short-term assignments as well as the on the management of such assignments. The paper identifies various benefits and challenges involved in the use of short-term assignments both from the perspectives of the company and assignees. Furthermore, the findings support the view that a recent increase in the popularity of short-term assignments has not been matched by the development of HRM policies for such assignments. Research limitations/implications – As a single case study, limitations in the generalizability of the findings should be kept in mind. More large-scale research evidence is needed around different forms of international assignments beyond standard expatriation in order to fully capture the realities faced by international HRM specialists Practical implications – The paper identifies many challenges but also benefits of using short-term assignments. The paper reports in-depth findings on HR development needs that organizations face when expanding the use of such assignments. Social implications – The paper identifies many challenges but also benefits of using short-term assignments. The paper reports in-depth findings on HR development needs that organizations face when expanding the use of such assignments. Originality/value – Empirical research on short-term assignments is still very limited. In that way the paper provides much needed in-depth evidence on why such assignments are used, what challenges are involved in the use of such assignments and what kinds of HR-development needs are involved.

Writing in a non-standard Greek variety: Romanized Cypriot Greek in online chat

Cypriot Greek, a variety of Greek spoken in the island of Cyprus, is relatively distinct from Standard Greek in all linguistic domains. The regional variety does not have a standard, official orthography and it is rarely used for everyday written purposes. Following technological development and the emergence of Computer-mediated Communication, a Romanized version of written CG is now widely used in online text-based communication, among teenagers and young adults (Themistocleous, C. (2008), The use of Cypriot-Greek in synchronous computer-mediated communication (PhD thesis), University of Manchester). In this study, I present the innovative ways that Greek-Cypriots use Roman characters in an effort to represent features of their spoken language in their online writings. By analysing data obtained from channel #Cyprus of Internet Relay Chat, I demonstrate how the choice of writing in CG affects the ways that Roman characters are used. I argue that this practice is not just a response to technological constrains but it actually has a wider social significance.

A simple and non-destructive model for individual leaf area estimation in citrus

Introduction. Leaf area is often related to plant growth, development, physiology and yield. Many non-destructive models have been proposed for leaf area estimation of several plant genotypes, demonstrating that leaf length, leaf width and leaf area are closely correlated. Thus, the objective of our study was to develop a reliable model for leaf area estimation from linear measurements of leaf dimensions for citrus genotypes. Materials and methods. Leaves of citrus genotypes were harvested, and their dimensions (length, width and area) were measured. Values of leaf area were regressed against length, width, the square of length, the square of width and the product (length x width). The most accurate equations, either linear or second-order polynomial, were regressed again with a new data set; then the most reliable equation was defined. Results and discussion. The first analysis showed that the variables length, width and the square of length gave better results in second-order polynomial equations, while the linear equations were more suitable and accurate when the width and the product (length x width) were used. When these equations were regressed with the new data set, the coefficient of determination (R(2)) and the agreement index 'd' were higher for the one that used the variable product (length x width), while the Mean Absolute Percentage Error was lower. Conclusion. The product of the simple leaf dimensions (length x width) can provide a reliable and simple non-destructive model for leaf area estimation across citrus genotypes.