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.     

Testing a Self-Determination Theory Process Model for Promoting Glycemic Control Through Diabetes Self-Management.

A longitudinal study tested the self-determination theory (SDT) process model of health behavior change for glycemic control within a randomized trial of patient activation versus passive education. Glycosylated hemoglobin for patients with Type 2 diabetes (n=159) was assessed at baseline, 6 months, and 12 months. Autonomous motivation and perceived competence were assessed at baseline and 6 months, and the autonomy supportiveness of clinical practitioners was assessed at 3 months. Perceptions of autonomy and competence were promoted by perceived autonomy support, and changes in perceptions of autonomy and competence, in turn, predicted change in glycemic control. Self-management behaviors mediated the relation between change in perceived competence and change in glycemic control. The self-determination process model fit the data well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some consequences of violating selection restrictions in concrete and abstract sentences.

Conducted 3 experiments with a total of 280 undergraduates in which content word constituents were reassigned arbitrarily to different sentences in lists of simple sentences. Original and substituted sentences were rated for imagery, comprehensibility, and sensibleness and, in Exps II and III, were tested also for incidental and intentional recall. Substitutions produced a greater ratings decrement for concrete than for abstract sentences, reversing in some cases a comprehensibility and sensibleness superiority found for the original concrete sentences. This finding supports the hypothesis that greater selection restrictions are associated with concrete than with abstract concepts. Consistent with the notion that imaginal coding is relatively insensitive to semantic constraint violations, smaller rating decrements were produced by substitutions under an imaginal coding set than under either a comprehension or a sensibleness set. Differences in constraints fail to account for concrete/abstract differences in recall as indicated by the finding of an unqualified recall superiority for concrete material under all conditions of substitution. (French summary) (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How do the plants used in phytoremediation in constructed wetlands,a sustainable remediation strategy,perform in heavy‐metal‐contaminated mine sites?

This review draws on knowledge for the treatment of heavy‐metal leachate in contaminated mine sites. Mine waste rock dumps and tailings generate a continuous stream of metalliferous and saline leachate over the long term. The mining industry has many legacy sites, which have compromised aquatic ecosystems and groundwater because of heavy‐metal contamination. Chemical and engineering methods are available and have been extensively utilised. However, these methods require intensive energy and often produce substantial volumes of secondary waste. We therefore argue in favour of phytoremediation as a sustainable remediation strategy leading towards efficient and sustainable metal removal and immobilisation through constructed wetlands.     

Novel aromatic macrocyclic oligomers: intermediates for the preparation of high-performance polymers

Recent studies aimed at the development of macrocyclic oligomers as the intermediates for the preparation of high-performance polymers are reviewed. Efficient methods for the preparation of a range of cyclic oligomers, such as aryl ether ketones, aryl ether phthalazines, aryl ether isoquinolines, aryl ether phthalazinones, and arylene sulfides, have been developed. Cyclization was achieved via a nucleophilic aromatic substitution reaction under high-dilution conditions. The cyclic aryl ether oligomers undergo a facile ring-opening polymerization to form high molecular weight polymer. Cyclic oligomers containing an aromatic sulfide linkage also undergo a facile free-radical ring-opening polymerization to form high molecular weight polymers which can be amorphous or crystalline. Due to their low molecular weights, these cyclic oligomers have very low melt viscosities which makes them attractive intermediates for a variety of applications for which the conventionally prepared high molecular weight polymers would not be suitable.     

Flux measurements for a DD neutron generator using neutron activation analysis

The fast and maximum thermal neutron fluxes from the DD-109 neutron generator at the University of Sharjah were experimentally measured by the activation technique using different neutron reactions. The thermal and fast neutron fluxes were found to be 2.960 × 10~6 and6.186 × 10~7 n/cm~2 s, respectively. This was done to verify the modeling results for the optimum moderator thickness needed to maximize the thermal neutron flux. The optimum moderator thickness was found to be between 3.5 and4 cm. The present data were compared with the detailed MCNP model-based calculation performed in earlier work to simulate the generator.     

Hydrogen atom absorption in hydrogen-covered Pd(110) (1 × 2) missing-row surface

The absorption of H atom in H-covered Pd(110) (1 × 2) missing-row surface is investigated using density functional theory based calculations. For 1.5 monolayer H coverage, interaction among the adsorbed H atoms is found to be negligible and was verified by analyzing the electronic structure of the system and by comparing the calculated binding energies with low H coverage case. Neither the monoatomic absorption of H nor the assistance from the initially adsorbed H atom explains the experimentally observed presence of subsurface H in Pd(110) at high H coverage. Instead, H absorption is realized through the assistance of incoming H atoms from vacuum. The absorption of H in the H-covered surface is non-activated while the dissociation of H₂ is the rate-limiting process. Dissociation on ridge site is energetically more preferred than on trough site and the difference in the activation barrier is elucidated by investigating the electronic structures of the system.     

Extruded meat alternatives made from Maillard-reacted beef bone hydrolysate and plant proteins: part I – Effect of moisture content

This study investigated the effects of moisture content (MC) on the physicochemical properties of extruded meat alternatives made from Maillard-reacted beef bone hydrolysate and plant proteins. Samples were extruded at 170 °C (maximum barrel temperature), at 3.6 kg h⁻¹ (liquid feed rate) and at 1.8, 2.2, 2.6 and 3.0 kg h⁻¹ (dry feed rates) to obtain MC of 60%MC, 56%MC, 52%MC and 49%MC, respectively. Meat alternatives at 52%MC showed the greatest degree of texturisation. However, meat alternatives at 49%MC were the closest in terms of both textural and microstructural properties to reference sample, boiled chicken breast. Results from protein solubility suggested that a large amount of aggregated proteins were associated with hydrogen bonds, while disulphide bonds were the main contributor in the formation of fibrous structure in meat alternatives. Results showed that the change in MC as process parameter played an important role in the formation of fibrous structure in extruded meat alternatives.