A fractional-step lattice Boltzmann flux solver for axisymmetric thermal flows

ABSTRACT

A fractional-step lattice Boltzmann flux solver is proposed in this work for effective simulation of axisymmetric thermal flows with rotating walls. The predictor and corrector steps are introduced in the solver. In the predictor step, excluding axisymmetric effects, the intermediate flow variables are predicted by the lattice Boltzmann flux solver (LBFS), which applies the finite-volume method to discretize the conservative equations recovered by the standard lattice Boltzmann method (LBM). The fluxes of the LBFS at the cell interfaces are reconstructed by local application of the lattice Boltzmann (LB) model with three distribution functions. These three distribution functions are used respectively for calculating axial and radial velocities, azimuthal velocity, and internal energy. In the corrector step, the intermediate flow variables are corrected by considering the axisymmetric effects. The present method not only retains the simplicity of the LBM but also eliminates the complicated derivation process in the axisymmetric LB model. The reliability of the proposed solver is examined by its application to simulate natural convection in an annulus, the Rayleigh-Benard convection, mixed convection in a vertical tall annulus, and Wheeler’s benchmark problem in crystal growth. The numerical results obtained agree well with the published data.     

Synthesis of Porous α-Fe2O3 Nanorods as Catalyst Support and A Novel Method to Deposit Small Gold Colloids on Them

Two novel methods, one for preparation of porous α-Fe₂O₃ nanorod catalyst support and another for the deposition of gold (Au) particles on the catalyst support with high efficiency and high dispersion, were reported. In the former, FeO(OH) nanorods were first prepared by a mild hydrothermal synthesis using tetraethylammonium hydroxide (TEAOH) as the structure director. The FeO(OH) product was then converted to porous α-Fe₂O₃ nanorods via calcination at 300 °C. During this calcination, pores with a size distribution in the range of 1–5 nm were generated by removal of TEAOH molecules. By employing our invented Au colloid-based and sonication-assisted method, in which lysine was used as the capping agent and sonication was employed to facilitate the deposition of the Au particles, we were able to deposit very small Au particles (2–5 nm) into these pores. This method is rapid as the reaction/deposition is completed within 1 min. The prepared Au/α-Fe₂O₃-nanorod catalyst exhibited much higher catalytic activity than the Au/commercial α-Fe₂O₃ (Fluka) catalyst.     

Editorial.

This editorial introduces the current issue of the Journal of Theoretical and Philosophical Psychology (JTPP). It focuses on a new section developed for short discussion articles in JTPP. This new section includes short articles on critical thinking in psychology. The discussion articles in this issue are based on a symposium that was held in 2010 at the APA convention in San Diego. The symposium included contradictory voices regarding the notions of critical thinking in psychology and on the philosophical underpinnings of this competence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of QD concentrations and thermal annealing on the performance of self-assembly QD-OLEDs

We have fabricated and investigated the effect of CdSe/ZnS quantum dot (QD) concentrations on the performance of self-assembly hybrid inorganic/organic light emitting diodes (QD-OLEDs). The uniform distribution of QDs with controllable density was achieved using the conventional spin-coating method. There was a QD threshold concentration for the emission of QDs in QD-OLED. Below that threshold concentration we did not observe the QD emission from the QD-OLED. The best performance of QD-OLED was found for the QD concentration of -9 x 10(11) cm(-2). The QD electroluminescence intensity was increased about three times after the annealing of QD-OLED at 80 degrees C for about 20 minutes in nitrogen atmosphere. The QD electroluminescence peak energy was remain same before and after the annealing of QD-OLED. The maximum external quantum efficiency was around 2.1%. The effect of process parameters and the QD emission mechanism are discussed.     

Development of a simple recovery-enrichment system for enhanced detection of heat-injured Listeria monocytogenes in pasteurized milk

A simple anaerobic recovery-enrichment system, semisolid Penn State University (ssPSU) broth, that enhances recovery of heat-injured Listeria monocytogenes, was rapidly achieved in 10-ml screw-capped tubes by adding Bacto-agar (2.5 g/liter) and L-cysteine (0.5 g/liter) to Penn State University broth. Glucose was removed from the formulation for ssPSU broth to prevent the growth of thermoduric lactobacilli. Ferric ammonium citrate was added to ssPSU broth to detect esculin hydrolysis and to indicate the presumptive presence of L. monocytogenes. Replacement of phosphate buffer with 3-[N-morpholino]propanesulfonic acid (MOPS) buffer and addition of magnesium sulfate (15 mM) enhanced recovery and detection of L. monocytogenes heat treated at 62.8 degrees C for 20 min. D-Serine, at a concentration of 150 mM, was found to inhibit germination of Bacillus spp. spores but did not inhibit severely heat-injured L. monocytogenes. Finally, ssPSU broth was modified (to mPSU broth) to contain the following: (i) Bacto-agar, 2.5 g/liter; (ii) ferric ammonium citrate, 0.5 g/liter; (iii) MOPS buffer, pH 7.0; (iv) D-serine, 13.7 g/liter; (v) D-alanine, 11.6 g/liter; and (iv) magnesium sulfate, 1.81 g/liter. Incubation temperature significantly affected the recovery and detection of severely heat-injured L. monocytogenes. L. monocytogenes that were heat challenged in filter-sterilized whole milk at 62.8 degrees C for 20, 25, and 30 min could not be detected at incubation temperatures > or = 30 degrees C but were consistently detected after incubation at 25 degrees C for 174, 199, and 330 h, respectively. Heat-injured cells of L. monocytogenes that were added to various commercial brands of pasteurized whole milk were also detected using mPSU broth. When clostridial spores (10(4) spores per ml) were added to filter-sterilized milk containing either heat-injured or non-heat-injured L. monocytogenes, only the latter could be detected in mPSU broth. The mPSU broth system requires no purging with nitrogen gas to create anaerobic conditions and permits recovery, growth, and detection of L. monocytogenes in one vessel in the presence of thermoduric background microflora commonly found in pasteurized milk.     

A Database Approach Integrating A Visually Interactive Load Flow For Low Voltage System

This paper presents an alternative approach to a visually interactive load flow and distribution loss calculation for a radially operated distribution network in buildings. By using the proposed database structure, any distribution network can be specified and modeled effectively, including the whole types and sizes of cables under different installation methods. Based on our proposed solution algorithm, matched with the database structure, load flow results can be calculated directly without formulating the admittance matrix. Thus, there is practically no limit to the number of nodes, and thus it does not require sparse techniques in matrix inversion. Any breaker in the network can be operated or tripped and a new load flow will be calculated and displayed. Based on the information in the database and a drawing algorithm, the single-line diagram of the network is drawn automatically and the calculated results can be dynamically positioned on the single line diagram. Test results confirm that the proposed system provides almost identical solution as compared with the conventional method.     

Three-dimensional static solutions of rectangular plates by variant differential quadrature method

An endeavor to exploit three-dimensional elasticity solutions for bending and buckling of rectangular plates via the differential quadrature (DQ) and harmonic differential quadrature (HDQ) methods is performed. Unlike other works, the priority of this paper is to examine the computational characteristics of the two methods; therefore, we focus our studies only on the simply supported and clamped rectangular plates. To start with, we first outline the basic equations and boundary conditions describing the bending and buckling of rectangular plates followed by normalizing and discretizing them according to the DQ and HDQ algorithms. The resulting algebraic equation systems are then solved to obtain the solutions. Based on these solutions, the computational characteristics of the DQ and HDQ methods are investigated in terms of their numerical performances. It is found that the DQ method displays obvious superior convergence characteristics over the HDQ method for the three-dimensional static analysis of rectangular plates.     

Molecular Mechanism of Granulation. II: Proton Translocating Activity

A laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used in this study to produce granular sludge at mesophilic temperatures (35 ± 1°C). After more than 150 days of operation, a COD removal efficiency of 95% was achieved with an organic loading rate of 8.73 gCOD∕L∕day. At the same time, the sludge granulation process was observed. The mature granules were examined for their stability in terms of the presence of calcium ion, surfactant, pH (buffer and H2SO4∕NaOH solution), metabolic inhibitor (iodoacetic acid and sodium fluoride), and proton translocator (carbonyl cyanide m-chlorophenyl-hydrazone). The results showed that bacterial surface dehydration, biological metabolic activity, and proton translocating activity were directly related to the strength of UASB granules. This indicated that the proton translocating activity on bacterial surfaces was the crucial factor in sludge granulation and, as a consequence, supported the proton translocation-dehydration theory. Experimental results from other studies were also used to support this new theory.     

Review of Self and identity in modern psychology and Indian thought.

Reviews the book, Self and identity in modern psychology and Indian thought by Anand C. Paranjpe (see record 1998-08117-000). This book is an exemplary philosophical-psychological achievement, the result of extensive, sophisticated, and enlightened research. Paranjpe analyzes and compares, based on knowledge of the epistemological, ontological, and ethical foundations of psychology in both the West and India, the problem of person, self, and identity. This is a significant book, not only for the field of the history and theory of psychology but also for psychology in general. Paranjpe, who provides a wealth of knowledge unknown to most Western psychologists, demonstrates that the presumption that Western and Indian psychologies are basically incommensurable is wrong. Psychologists who are genuinely concerned with a science that goes beyond the connection of variables, who believe that incorporating a multicultural perspective into psychology will strengthen the discipline, and who talk about globalization but are interested in the generic meaning of this concept, cannot ignore this masterpiece. (PsycINFO Database Record (c) 2010 APA, all rights reserved)