A Galerkin-reproducing kernel method: Application to the 2D nonlinear coupled Burgers' equations

The paper introduces a Galerkin method in the reproducing kernel Hilbert space. It is implemented as a meshless method based on spatial trial spaces spanned by the Newton basis functions in the “native” Hilbert space of the reproducing kernel. For the time-dependent PDEs it leads to a system of ordinary differential equations. The method is used for solving the 2D nonlinear coupled Burgers' equations having Dirichlet and mixed boundary conditions. The numerical solutions for different values of Reynolds number (Re) are compared with analytical solutions as well as other numerical methods. It is shown that the proposed method is efficient, accurate and stable for flow with reasonably high Re in the case of Dirichlet boundary conditions.     

Chromatographic separation of clenbuterol by bonded phases bearing nano-baskets of p-tert-calix[4]-1,2-crown-3, -crown-4, -crown-5 and -crown-6

BACKGROUND: Clenbuterol (salbutamol), which increases muscle mass and decreases adipose tissue, is misused as a nutrient‐repartitioning agent in livestock. In this paper a new sensitive method for determining clenbuterol in livestock is presented. The novelty of this approach is the separation and determination of salbutamol enantiomers with marked quantitative merits. RESULTS: Four proton di‐ionisable Nano‐baskets, namely 5,11,17,23‐tetrakis(1,1‐dimethylethyl)‐25,26‐bis(carboxy‐methoxy)calix[4]arene‐27,28‐crown‐3, ‐crown‐4, ‐crown‐5 and ‐crown‐6 in the cone conformation, were synthesised and used to prepare bonded phases for high‐performance liquid chromatography separation. The new synthesised bonded phases were characterised and optimised. The bonding interactions of solute/bonded phases were examined and the main interactions are reported. CONCLUSION: The clenbuterol levels in six samples of livestock meat (pork, pork casing, beef, beef casing, mutton and mutton casing) were analysed and the results revealed that for the best bonded phases the limits of detection and quantitation were 0.06 and 0.2 µg mL^?1 respectively. Copyright © 2012 Society of Chemical Industry     

Optimization of turning process using artificial intelligence technology

In the current work, some experiments were performed based on a design of experiment (DOE) technique called full factorial design. The experimental results are discussed in statistical analysis, and the system was modeled using the artificial neural network (ANN) and subsequently optimized by a genetic algorithm (GA). The statistical analysis shows that the main effects and some 2-interaction effects affect the surface roughness and flank wear. The results show that the feed rate, nose radius, and approach angle have a significant effect on the flank wear and the surface roughness, but the cutting velocity has a significant effect on the flank wear alone. The optimum values of cutting parameters were identified and the resultant optimum values of flank wear and surface roughness were found to be in good agreement with the results of a validation experiment under a similar condition. The optimized values showed a significant reduction in roughness and flank wear.     

Direct Synthesis of CdO Nanoparticles from a Novel Nano-Rods Cadmium(II) 4,4-Difluoro-1-phenyl-1,3-butanedionate Nano Coordination Compound

A novel nano-rods cadmium(II) fluorine-substituted β-diketonate, [Cd(2,2′-bpy)(dfpb)₂] (1), (2,2′-bpy = 2,2′-bipyridine; dfpb = 4,4-difluoro-1-phenyl-1,3-butandion) has been synthesized by a sonochemical method that produces the coordination compound with nano dimensions. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction (XRD) elemental analysis and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction. The single-crystal structure of this complex shows that the coordination number of the Cd^II ions is six with two N-donor atoms from the 2,2′-bpy ligand and four O-donors from two dfpb. Self-assembly of the complex occurs through CH···F–C and π–π stacking interactions. The supramolecular features of 1 are controlled by weak directional intermolecular interactions. CdO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by the Scherrer equation to be 20 nm. The morphology and size of the CdO samples were further observed using SEM.     

Effect of feed composition on PHB production from methanol by HCDC of Methylobacterium extorquens (DSMZ 1340)

BACKGROUND: Poly‐β‐hydroxybutyrate (PHB), produced by several species of bacteria, has attracted great attention as a biodegradable and biocompatible compound with similar properties to polypropylene. Unfortunately, its use is currently limited due to high production costs. One of the most common methods for overcoming this constraint is the use of inexpensive substrates, like methanol, in high cell density cultivations (HCDC). RESULTS: Fermentation was carried out with optimized feed composition (639 g l^?1 methanol, 4 g l^?1 MgSO₄.7H₂O, 41 mL L^?1 trace elements, 5.6 g L^?1 NaH₂PO₄.H₂O and 24.3 g L^?1 K₂HPO₄) and a feeding strategy based on the detection of substrate limitation by dissolved oxygen (DO). After 35 h, at which dry cell weight (DCW) reached a value of 70 g L^?1, PHB production was stimulated, and biomass and PHB productivities of 2.8 and 0.98 g L^?1 h^?1 were obtained, respectively. These results surpassed those reported in the literature for PHB production from methanol by Methylobacterium species. CONCLUSION: The proposed feed composition and feeding strategy for PHB production from methanol by Methylobacterium extorquens 1340 in fed‐batch cultivation resulted in high biomass and PHB productivity. They can be implemented for recombinant bioproducts (proteins) produced by M. extorquens due to the lack of PHB accumulation in the growth phase. Copyright © 2009 Society of Chemical Industry     

Towards a Feasible Active Networking Scenario

We investigate the impact of introducing active networking on traditional packets flowing through the active nodes of a network. Using two approaches, the process algebra formalism PEPA and the simulation package SimJava, we compare the performance of an active node and of a traditional one. We are mainly interested in performance measures such as loss rates of standard packets and the node latency for this kind of packets.     

Static Tensile and Transient Dynamic Response of Cracked Aluminum Plate Repaired with Composite Patch – Numerical Study

In this study, the central cracked aluminum plates repaired with two sided composite patches are investigated numerically for their response to static tensile and transient dynamic loadings. Contour integral method is used to define and evaluate the stress intensity factors at the crack tips. The reinforcement for the composite patches is carbon fibers. The effect of adhesive thickness and patch thickness and configuration in tensile loading case and pre-tension, pre-compression and crack length effect on the evolution of the mode I stress intensity factor (SIF) (K_I) of the repaired structure under transient dynamic loading case are examined. The results indicated that K_I of the central cracked plate is reduced by 1/10 to 1/2 as a result of the bonded composite patch repair in tensile loading case. The crack length and the pre-loads are more effective in repaired structure in transient dynamic loading case in which, the 100 N pre-compression reduces the maximum K_I for about 40 %, and the 100 N pre-tension reduces the maximum K_I after loading period, by about 196 %.     

Excitonic absorption in GaSe and InSe crystals under picosecond excitation

The nonlinear light absorption in GaSe and InSe layered crystals in the exciton resonance region and its time evolution have been studied experimentally under high-density optical excitation. The observed variation of the absorption coefficient with time and excitation intensity is due not only to exciton-exciton interaction and the shielding of excitons by nonequilibrium carrier plasma but also to kinetic and relaxation-recombination processes in these materials.     

Assessing students' metacognitive awareness of reading strategies.

This article describes the development and validation of a new self-report instrument, the Metacognitive Awareness of Reading Strategies Inventory, which is designed to assess adolescent and adult readers' metacognitive awareness and perceived use of reading strategies while reading academic or school-related materials. There were 3 strategy subscales or factors: Global Reading Strategies, Problem-Solving Strategies, and Support Reading Strategies. The reliability and factorial validity of the scale were demonstrated. After a brief review of the literature, the development and validation of the instrument are described, and its psychometric properties are discussed. In addition, directions for administering and scoring the instrument are provided, and suggestions for interpreting the results obtained are offered. Finally, the scales' implications for reading research and instruction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)