Nodal DG-FEM solution of high-order Boussinesq-type equations

A discontinuous Galerkin finite-element method (DG-FEM) solution to a set of high-order Boussinesq-type equations for modelling highly nonlinear and dispersive water waves in one horizontal dimension is presented. The continuous equations are discretized using nodal polynomial basis functions of arbitrary order in space on each element of an unstructured computational domain. A fourth-order explicit Runge-Kutta scheme is used to advance the solution in time. Methods for introducing artificial damping to control mild nonlinear instabilities are also discussed. The accuracy and convergence of the model with both h (grid size) and p (order) refinement are confirmed for the linearized equations, and calculations are provided for two nonlinear test cases in one horizontal dimension: harmonic generation over a submerged bar, and reflection of a steep solitary wave from a vertical wall. Test cases for two horizontal dimensions will be considered in future work.     

High Order Finite Difference Approximations of Electromagnetic Wave Propagation Close to Material Discontinuities

Electromagnetic wave propagation close to a material discontinuity is simulated by using summation by part operators of second, fourth and sixth order accuracy. The interface conditions at the discontinuity are imposed by the simultaneous approximation term procedure. Stability is shown and the order of accuracy is verified numerically.     

A functional correspondence between call-by-need evaluators and lazy abstract machines

We bridge the gap between compositional evaluators and abstract machines for the lambda-calculus, using closure conversion, transformation into continuation-passing style, and defunctionalization of continuations. This article is a followup of our article at PPDP 2003, where we consider call by name and call by value. Here, however, we consider call by need.We derive a lazy abstract machine from an ordinary call-by-need evaluator that threads a heap of updatable cells. In this resulting abstract machine, the continuation fragment for updating a heap cell naturally appears as an ‘update marker’, an implementation technique that was invented for the Three Instruction Machine and subsequently used to construct lazy variants of Krivine's abstract machine. Tuning the evaluator leads to other implementation techniques such as unboxed values. The correctness of the resulting abstract machines is a corollary of the correctness of the original evaluators and of the program transformations used in the derivation.     

Engineering the Thermoelectrical Properties of PEDOT:PSS by Alkali Metal Ion Effect

Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such a...     

Implementing knowledge building: Analysis of a face‐to‐face discussion by grade‐four students

Abstract:

Researchers say that teachers can implement an educational innovation without adhering to the principles underpinning its design. Such principles may not adequately take typical classroom conditions into account. The goal of this study was to explore tensions between attempts to implement the principles underpinning knowledge building and the influence of contextual factors that compete for the teacher's attention. To this end, we discuss five excerpts from a discussion of the motion of spinning tops held by a class of Grade‐4 students, coming at the end of a five‐month implementation of knowledge building. Each excerpt is followed first by the teacher's perspective and then by the researcher's perspective. Our analysis highlights two tensions that constrain agency, arising from the students’ need for social development and their need to learn scientific concepts. We offer some suggestions for addressing these tensions.     

Reconfigurable handling system

The demand for more versatile assembly and handling systems to facilitate customized production is gaining in importance, especially with regard to the constantly-increasing cost pressure, to expansion of the range of product versions and the shortening of innovation cycles. As a cost-effective approach for frequently changing assembly tasks, a novel manipulation concept has been developed by combining given robot technologies. This new handling system has a modular and adaptable layout, which consists of several mobile arms to manipulate the object in six-dimensional Cartesian space. After grasping, when the arms are attached to the object, the mechanical architecture is similar to parallel manipulators or cooperating robots. As the mounting and gripping points of the arms can easily be changed, the manipulator can be reconfigured so as to match the user’s preferences and needs. In addition to the kinematic adaption the regarding task, the hardware and new functions can be reconfigured as well. Contact elements, measurement and assembly devices as well as testing modules can easily be in integrated in the concept. A modular automatic control concept combined with a self-optimizing planning tool helps the user to find the optimal configuration and realize it in an economic way.     

Thermal comfort of patients: Objective and subjective measurements in patient rooms of a Belgian healthcare facility

In healthcare facilities, the prediction of mean thermal comfort perception of patients and staff is necessary to formulate requirements for the architectural and building systems design and control, and for establishing guidelines for the use of clothing and bedding systems.     

流动城市

这是一个在商业公园、港口和机场之间开发的项目,要求不能违背大加那利群岛的地理特质。我们的目标是提高这些本地条件,注入明确的城市规划和景观规划方案。我们计划建立3个超级区域网络:东西向的地景河床     

Determination of aryloxyphenoxypropanoic acid derivatives in crops treated with herbicidal sprays

Summary A reproducible and sensitive gas Chromatographic method has been developed for the trace analysis of fluazifop-butyl, haloxyfop-ethoxyethyl and quizalofop-ethyl as well as their main metabolites (corresponding acids analysed after conversion to methyl esters) in some fruits and vegetables treated with herbicidal sprays. Comparable detection limits (0.01 mg/kg) were achieved when mass fragmentography and/or the electron capture detector were employed. However, in the latter case, bromination of fluazifop esters had to be carried out prior to GC analysis. By means of the nitrogen-phosphorus detector, determination of residues at a level of 0.05 mg/kg was possible. The residue values found in strawberries, cabbages, cauliflowers and carrots were used to discuss the degree of metabolic hydrolysis of parent esters, i.e. active ingredients of herbicides.

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Bestimmung von Aryloxyphenoxypropionsäure-Derivaten in mit Herbicidsprays behandelten Produkten

Zusammenfassung Es wurde eine gaschromatographische Methode zur quantitativen und selektiven Bestimmung von Fluazifop-butyl, Haloxyfop-ethoxyethyl und Quizalofop-ethyl sowie von ihren Hauptmetaboliten (den entsprechenden Säuren, die zu Methylestern umgesetzt werden müssen) in mit Herbiciden behandelten Obst- und Gemüseproben entwickelt. Eine Nachweisgrenze von 0,01 mg/kg wurde durch Elektroneneinfanggaschromatographie oder durch Massenfragmentographie erzielt. Um die gleiche Empfindlichkeit des EC-Detektors bei Fluazifop zu erreichen, wurden die beiden Ester mit Brom umgesetzt. Mit Hilfe des NP-Detektors konnte eine Nachweisgrenze von 0,05 mg/kg erreicht werden. Die festgestellten Rückstandsgehalte in Erdbeeren, Kohl, Blumenkohl und Möhren wurden gleichzeitig zur Beurteilung der metabolischen Hydrolyse der diskutierten Ester (der Wirkstoffe der Herbicide) herangezogen.