Local Grid Refinement in Large-Eddy Simulation

A method for performing nested-grid calculations with a Large-Eddy Simulation (LES) code is described. The grid consists of a coarse mesh and a fine mesh which overlaps the coarse in some region. A standard finite-volume method is used on both meshes. By means of grid communication, the velocity and pressure at both meshes are matched. To check that large eddies which are already resolved on the coarse grid are not affected by the nesting procedure, a simple two-dimensional mixing layer is simulated. Several simulations of this flow have been carried out with a different number of grid points on the nested grid. It is found that, without much extra computational effort, the grid-nesting improves the turbulent statistics with respect to the results found on the coarse mesh. This improvement occurs first of all in the region where grid refinement is applied, but better results are also found on the coarse mesh outside the grid-refinement region. Furthermore, it is shown that the large-scale structures in this flow are not influenced by the boundary between the coarse and fine grid.     

Note on an integral equation of viscous flow theory

Summary The integral equation encountered by Van de Vooren and Veldman in a problem of viscous flow was recently solved by Brown by use of the Wiener-Hopf technique. In this note Brown's solution is re-derived by a different, function-theoretic method.     

Expression of the multidrug resistance-associated protein (MRP) gene in human cancers

We determined the expression of a newly recognized drug resistance gene, the multidrug resistance-associated protein (MRP) gene, [Cole et al., Science (Washington DC), 258: 1650-1654, 1992], in normal human tissues and in >370 human tumor biopsies using a quantitative RNase protection assay and immunohistochemistry. MRP mRNA appeared to be ubiquitously expressed at low levels in all normal tissues, including peripheral blood, the endocrine glands (adrenal and thyroid), striated muscle, the lymphoreticular system (spleen and tonsil), the digestive tract (salivary gland, esophagus, liver, gall bladder, pancreas, and colon), the respiratory tract (lung), and the urogenital tract (kidney, bladder, testis, and ovary). The human cancers analyzed could be divided into three groups with regard to MRP expression. Group 1 consists of tumors that often exhibit high to very high MRP mRNA levels (e.g., chronic lymphocytic leukemia). Group 2 comprises the tumors that often exhibit low, but occasionally exhibit high MRP mRNA expression (e.g., esophagus squamous cell carcinoma, non-small cell lung cancer, and acute myelocytic leukemia). Group 3 comprises the tumors with predominantly low levels of MRP mRNA, comparable to the levels found in normal tissues (e.g., other hematological malignancies, soft tissue sarcomas, melanoma, and cancers of the prostate, breast, kidney, bladder, testis, ovary, and colon). Using the MRP-specific mAbs MRPr1 and MRPm6, we confirmed the elevated MRP mRNA levels in tumor tissues by immunohistochemistry. We conclude that hyperexpression of MRP is observed in several human cancers, and that additional studies are needed to assess the clinical relevance of MRP.     

Affective variables and school achievement: A study of possible causal influences.

Studied the predictive and causal relationship of affective variables and academic achievement (376 Ss in Grades 3–6), both concurrently and 1 yr later. Affective characteristics studied were general and academic self-concept, academic locus of control, and expectations for future academic achievement (Piers-Harris Children's Self-Concept Scale, Student's Perception of Ability Scale, Intellectual Achievement Responsibility Questionnaire, and the Projected Academic Performance Scale) whereas levels of achievement were ascertained by end-of-year grades. The findings indicate that affective variables, especially academic self-concept, made a small but significant contribution to school grades. The data suggest a possible reciprocal interaction between affective characteristics and school achievement. Implications for children experiencing learning difficulties are discussed. (French abstract) (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of a second order gas-solid reaction in an isothermal spherical particle. Application to the reduction of oxides with gaseous substrates

The mass transport equation applying to a second order gas solid reaction taking place in an isothermal spherical particle is solved by the orthogonal collocation method, using 3, 5 and 8 point collocation. The results are compared with those obtained in earlier studies using different assumptions and calculation procedures.     

Creativity (Ideas) Management in Industrial R&D Organizations: A Crea‐Political Process Model and an Empirical Illustration of Corus RD&T

Creativity management is a crucial topic to consider in the debate about the innovative research department. Against the background of discussions about individual creativity and organizational commitment, this article argues that the creative process in organizations is a matter of political strategies. The ideator literally has to sell his/her idea. The article therefore comes up with a crea‐political process model in which there is ample room for the thought that ideas emerge and survive within a social‐political context. In addition, the crea‐political process model is used to analyse the way in which the Corus Group Research Development and Technology (RD&T) department has implemented an electronic idea‐management system. The system, called eureka!, has been designed as a straightforward platform to capture, review, evaluate and select creative ideas. The findings challenge the literature on idea management in organizations to consider the political activities of ideators in the whole process of creativity.