Amino acid composition of guineafowl's egg

Samples of eggs from two breeds (White-breasted and Pearl) of guinea hens which were housed either on deep litter or in layer cages were analysed for their content of amino acids. The protein content of whole eggs ranged from 482 to 494 mg g^?1, with a mean of 487 mg g^?1. Concentrations of the various amino acids in the egg ranged from 118 mg (tryptophan) to 752 mg (glutamic acid) per g N. The mean concentration of total sulphur amino acids was 395 mg per g N. Overall the amino acid composition of guineafowl egg was not affected by either breed or housing system.     

Towards a New MODDE of Improving Legal Decision Support Design

This paper contributes to the ebb and flow of innovations in decision support system design by presenting the MODDE methodology (Model Of Decision support system Design and Evaluation). It utilizes a simple conceptualisation of the software engineering process, and aims to provide computer consultants with guidance to the way they may include consideration of three qualitative dimensions of high level autonomous decision making. These three dimensions--discretion, consistency and resolution--have arisen directly from work in an applied legal domain. MODDE facilitates systematic attention to these dimensions in a way not previously done and thus complements existing software and requirements engineering practices.     

A Level-Crossing Analog-to-Digital Converter With Triangular Dither

In this paper, a level-crossing analog-to-digital converter is described. It can convert audio bandwidth signals with high resolution using few threshold levels and digital interpolation. Samples are generated at nonuniform time intervals and then interpolated to produce uniformly spaced output samples. A periodic triangular dither signal added to the input ensures that low-amplitude or slowly varying signals are sampled and converted accurately. The dither is estimated and removed digitally before interpolation. Simulations show that greater than 10-bit resolution can be achieved with only seven comparators when using a sixth-order polynomial interpolator.     

Three‐dimensional optimisation of a fuel gas channel of a proton exchange membrane fuel cell for maximum current density

Proton exchange membrane (PEM) fuel cells operated with hydrogen and air offer promising alternative to conventional fossil fuel sources for transport and stationary applications because of its high efficiency, low‐temperature operation, high power density, fast start‐up and potable power for mobile application. Power levels derivable from this class of fuel cell depend on the operating parameters. In this study, a three‐dimensional numerical optimisation of the effect of operating and design parameters of PEM fuel cell performance was developed. The model computational domain includes an anode flow channel, membrane electrode assembly and a cathode flow channel. The continuity, momentum, energy and species conservation equations describing the flow and species transport of the gas mixture in the coupled gas channels and the electrodes were numerically solved using a computational fluid dynamics code. The effects of several key parameters, including channel geometries (width and depth), flow orientation and gas diffusion layer (GDL) porosity on performance and species distribution in a typical fuel cell system have been studied. Numerical results of the effect of flow rate and GDL porosity on the flow channel optimal configurations for PEM fuel cell are reported. Simulations were carried out ranging from 0.6 to 1.6 mm for channel width, 0.5 to 3.0 mm for channel depth and 0.1 to 0.7 for the GDL porosity. Results were evaluated at 0.3 V operating cell voltage of the PEM fuel cell. The optimisation results show that the optimum dimension values for channel depth and channel width are 2.0 and 1.2 mm, respectively. In addition, the results indicate that effective design of fuel gas channel in combination with the reactant species flow rate and GDL porosity enhances the performance of the fuel cell. The numerical results computed agree well with experimental data in the literature. Consequently, the results obtained provide useful information for improving the design of fuel cells. Copyright © 2011 John Wiley & Sons, Ltd.     

Entropy generation on MHD flow of a Casson fluid over a curved stretching surface with exponential space-dependent heat source and nonlinear thermal radiation

The present model concentrates on entropy generation on a steady incompressible flow of a Casson liquid past a permeable stretching curve surface through chemical reaction and magnetic field effects. The exponential space-dependent heat source cum heat and mass convective boundary conditions are accounted for. The resulting nonlinear boundary layer model is simplified by the transformation of similarity. Chebyshev spectral technique is involved for obtaining numerical results of the converted system of the mathematical models. Behavior of the determining thermo-physical parameters on the profiles of velocity, temperature, concentration, skin friction, heat, mass transfer rate, rate of entropy generation, and finally the Bejan number are presented. The major point of the present investigation show that the curvature term weakens the mass transfer profile as the fluid temperature reduces all over the diffusion regime. A decrease in heat generation strengthens the species molecular bond, which prevents free Casson particle diffusion. Furthermore, the mass transfer field diminishes in suction and injection flow medium.     

Entropy generation in MHD Williamson nanofluid over a convectively heated stretching plate with chemical reaction

This investigation focuses on the influence of thermal radiation on the magnetohydrodynamic flow of a Williamson nanofluid over a stretching sheet with chemical reaction. The phenomena at the stretching wall assume convective heat and mass exchange. The novelty of the present study is the thermodynamic analysis in the nonlinear convective flow of a Williamson nanofluid. The resulting set of the differential equations are solved by the homotopy analysis method. We explored the impacts of the emerging parameters on flow, heat, and mass characteristics, including the rate of entropy generation and the Bejan number through graphs, and extensive discussions are provided. The expressions for skin friction, Nusselt and the Sherwood numbers are also analyzed and explored through tables. It is concluded that the rate of mass transfer may be maximized with the variation of the Williamson and chemical reaction parameters. Moreover, the entropy generation rate and the Bejan number are augmented via increasing the Williamson parameter.     

Nonlinear thermal radiation on MHD tangential hyperbolic hybrid nanofluid over a stretching wedge with convective boundary condition

In this study, two distinct nanoparticles: aluminum oxide (Al₂O₃) and copper (Cu) are chosen as nanomaterials to examine the effects of nonlinear electrically conducting magnetohydrodynamic radiation on the flow of tangential hyperbolic hybrid nanofluid across a nonlinearly stretched sheet with convective boundary conditions. The equations that regulate fluid flow are represented as partial differential equations. These equations are reduced to their equivalent ordinary differential equations, which are solved using the homotopy analysis approach with the help of similarity variables. The effect of essential physical factors on fluid velocity, temperature, skin friction coefficient, and local Nusselt number is investigated and discussed. Results ascertain that the heat transfer rate of Cu/H₂O nanofluid becomes high when equated to Cu–Al₂O₃/H₂O nanofluid. Furthermore, the temperature distribution enhances with the rise in solid volume fraction while it diminishes with improved magnetic field for both nanofluid and hybrid nanofluid.     

Food insecurity and coping strategies in South-West Nigeria

Food insecurity and coping strategies in Ado-Ekiti, Ekiti State in the south-western part of Nigeria were studied by means of a multistage sampling technique. Data were collected from 80 households, consisting of 321 members, with the aid of a well-structured questionnaire, and were analysed using a Food Insecurity Index. The overall incidence of food insecurity was 58.8 % while the depth of food insecurity, expressed as the average percent increase in calories required to meet the recommended daily requirement, was 19.5 %. Thus, the study confirmed the widespread existence of household food insecurity but with mild severity. Food insecurity indices declined with higher levels of income and educational attainment but increased with household size and number of dependants. Incidence of food insecurity was slightly higher among female headed than male headed households but the depth and severity were lower. Eating less expensive and less preferred food and reducing portion sizes were the three most common coping strategies for combating short-term food shortages. Policies that would enhance income earning capacity of household members and their access to higher education, well-focused gender specific interventions and promotion of backyard farming are advocated.     

Fate of sulphate removed during the treatment of circumneutral mine water and acid mine drainage with coal fly ash: Modelling and experimental approach

The treatment of acid mine drainage (AMD) and circumneutral mine water (CMW) with South African coal fly ash (FA) provides a low cost and alternative technique for treating mine wastes waters. The sulphate concentration in AMD can be reduced significantly when AMD was treated with the FA to pH 9. On the other hand an insignificant amount of sulphate was removed when CMW (containing a very low concentration of Fe and Al) was treated using FA to pH 9. The levels of Fe and Al, and the final solution pH in the AMD–fly ash mixture played a significant role on the level of sulphate removal in contrast to CMW–fly ash mixtures. In this study, a modelling approach using PHREEQC geochemical modelling software was combined with AMD–fly ash and/or CMW–fly ash neutralization experiments in order to predict the mineral phases involved in sulphate removal. The effects of solution pH and Fe and Al concentration in mine water on sulphate were also investigated. The results obtained showed that sulphate, Fe, Al, Mg and Mn removal from AMD and/or CMW with fly ash is a function of solution pH. The presence of Fe and Al in AMD exhibited buffering characteristic leading to more lime leaching from FA into mine water, hence increasing the concentration of Ca²⁺. This resulted in increased removal of sulphate as CaSO₄·2H₂O. In addition the sulphate removal was enhanced through the precipitation as Fe and Al oxyhydroxysulphates (as shown by geochemical modelling) in AMD–fly ash system. The low concentration of Fe and Al in CMW resulted in sulphate removal depending mainly on CaSO₄·2H₂O. The results of this study would have implications on the design of treatment methods relevant for different mine waters.