In situ observations on the austenite stability in TRIP‐steel during tensile testing

In‐situ deformation tests have been performed on a steel displaying the transformation‐induced plasticity (TRIP) effect, while monitoring the phase transformation by means of X‐ray diffraction. A tensile stress is applied to 0.4 mm thick samples of this steel with mass contents of 0.26 % Si, 1.5 % Mn, and 1.8 % Al in a transmission geometry for a synchrotron‐radiation beam of 25 μm · 25 μm. On the diffraction patterns every grain appears as a discrete spot. The austenite {200} reflections are analysed during this investigation. The diffraction patterns are treated like a powder pattern for five different η‐angles, with η representing the angle between the tensile direction and the normal direction of the diffracting {200} planes. The results of the analysis show that η = 0° and η = 90° are the preferential orientations for the transformation to martensite. The Ludwigson and Burger model [9] is used to gain more information about the stress dependence of the deformation induced martensite formation. The microdiffraction patterns also reveal the changes in carbon concentration in austenite at each retained austenite fraction.     

Beyond Good Partition Shapes: An Analysis of Diffusive Graph Partitioning

In this paper we study the prevalent problem of graph partitioning by analyzing the diffusion-based partitioning heuristic Bubble-FOS/C, a key component of a practical successful graph partitioner?(Meyerhenke et al. in J. Parallel Distrib. Comput. 69(9):750?C761, 2009). We begin by studying the disturbed diffusion scheme FOS/C, which computes the similarity measure used in Bubble-FOS/C and is therefore the most crucial component. By relating FOS/C to random walks, we obtain precise characterizations of the behavior of FOS/C on tori and hypercubes. Besides leading to new knowledge on FOS/C (and therefore also on Bubble-FOS/C), these characterizations have been recently used for the analysis of load balancing algorithms?(Berenbrink et al. in Proceedings of the 22nd Annual Symposium on Discrete Algorithms, pp. 429?C439, 2011). We then regard Bubble-FOS/C, which has been shown in previous experiments to produce solutions with good partition shapes and other favorable properties. In this paper we prove that it computes a relaxed solution to an edge cut minimizing binary quadratic program (BQP). This result provides the first substantial theoretical insight why Bubble-FOS/C yields good experimental results in terms of graph partitioning metrics. Moreover, we show that in bisections computed by Bubble-FOS/C, at least one of the two parts is connected. Using the aforementioned relation between FOS/C and random walks, we prove that in vertex-transitive graphs both parts must be connected components.     

Group codes on certain algebraic curves with many rational points

We construct a series of algebraic geometric codes using a class of curves which have many rational points. We obtain codes of lengthq ² over _q , whereq = 2q ₀ ² andq ₀ = 2 ⁿ , such that dimension + minimal distance q ² + 1 – q ₀ (q – 1). The codes are ideals in the group algebra _q [S], whereS is a Sylow-2-subgroup of orderq ² of the Suzuki-group of orderq ² (q ² + 1)(q – 1). The curves used for construction have in relation to their genera the maximal number of GF _q -rational points. This maximal number is determined by the explicit formulas of Weil and is effectively smaller than the Hasse—Weil bound.Supported by Deutsche Forschungsgemeinschaft while visiting Essen University     

优化乙醇和食糖混合生产过程

新型控制系统平台帮助糖类产品生产商,根据变化的市场需要,最优化食用糖和纯乙醇的混合生产过程。     

Participatory ergonomics: development of an employee assessment questionnaire

Despite being essential to the success of participatory ergonomics (PEs) programs, there are currently no known quantitative measures that capture the employees’ perspective of PE program effectiveness. The present study addresses this need through the development of the Employee Perceptions of Participatory Ergonomics Questionnaire (EPPEQ). The questionnaire is designed to assess five key components that are based on a review of the available literature: Employee Involvement, Knowledge Base, Managerial Support, Employee Support, and Strain related to ergonomic changes. In Phase 1, a sample of employees and ergonomists working at a manufacturing plant was used to develop and test an initial set of items. In Phase 2, data was collected from a nation-wide sample of employees representing a wide range of jobs and organizations to cross-validate the results from Phase 1. Phase 2 results indicate that the five EPPEQ subscales demonstrate sound convergent validity and are also correlated with traditional indicators of PE program success. Implications and uses of the EPPEQ are discussed.     

Advances in Human Mitochondria-Based Therapies

Mitochondria are the key biological generators of eukaryotic cells, controlling the energy supply while providing many important biosynthetic intermediates. Mitochondria act as a dynamic, functionally and structurally interconnected network hub closely integrated with other cellular compartments via biomembrane systems, transmitting biological information by shuttling between cells and tissues. Defects and dysregulation of mitochondrial functions are critically involved in pathological mechanisms contributing to aging, cancer, inflammation, neurodegenerative diseases, and other severe human diseases. Mediating and rejuvenating the mitochondria may therefore be of significant benefit to prevent, reverse, and even treat such pathological conditions in patients. The goal of this review is to present the most advanced strategies using mitochondria to manage such disorders and to further explore innovative approaches in the field of human mitochondria-based therapies.     

Crossing the digital divide safely and trustingly: how ecologies of learning scaffold the journey

The article addresses the issue of learning to elearn in borderless programs in a globalised learning landscape and the associated problems of scaffolding the journey across the digital divide. The authors argue that the assumption underlying such courses is that cross-cultural programs are viable because they are conceived and designed to be ‘global’, and that they assume this design to be inclusive. Henning and Van der Westhuizen claim that the global discourse in most domains can take only marginal note of the need to infuse such programs with a local semiotic—a course design criterion for which they argue. They furthermore forward the notion that the majority of the world's prospective elearners need various bridging mechanisms in order to be able to access the broader discourse and that one of these mechanisms can be explored through the metaphor of “information ecologies” as proposed by Nardi and O'Day [Nardi, B.A., & O'Day, V.L. (1999). Information ecologies. Using technology with heart. Cambridge, MA: The MIT Press]. They also conclude that issues of the learners’ trust in the course and its system need to be considered when contemplating programs for diverse target groups. By way of a case study, consisting of three portraitures of adult learners, they explore the limitations of assumed distributed cognition and claim that learning is, in reality, contained/constrained in the familiar local narrative of the novice adult elearners in a rural South African context. The case study illustrates how the resistance to technology and its power base becomes an obstacle for the students and how the support of peers becomes the main scaffolding mechanism for their entry into electronic learning environments. The findings thus show how the social context becomes the facilitator and the scaffold for elearning, more than technology and the curriculum itself.