Effects of variable chemical reaction and variable electric conductivity on free convective heat and mass transfer flow along an inclined stretching sheet with variable heat and mass fluxes under the influence of Dufour and Soret effects

This paper deals with the effects of variable chemical reaction and variable electric conductivity on free convection and mass transfer flow of a viscous, incompressible and electrically conducting fluid over an inclined stretching sheet with variable heat and mass fluxes under the influence of Dufour and Soret effects. The non-linear boundary layer equations with boundary conditions are transferred into a system of non-linear ordinary differential equations using an established similarity transformation. These non-linear and locally-similar ordinary differential equations are solved numerically by applying Nachtsheim–Swigert shooting iteration technique with sixth-order Runge–Kutta integration scheme. Comparison with previously published work is obtained and excellent agreement is found. The effects of various parameters on the dimensionless velocity, temperature and concentration profiles as well as the local skin-friction coefficient, heat and mass transfer rate from the stretching sheet to the surrounding fluid are presented graphically and in tabulated form for a hydrogen-air mixture. The numerical results showed that chemical reaction parameter K, order of reaction n, Dufour number Df , Soret number Sr and heat (or mass) flux parameter r play a crucial role in the solutions

MEDIA OPTIMIZATION FOR BIOPROTEINS PRODUCTION FROM CHEAPER CARBON SOURCE

There are high demands for animal and human food supply especially protein, which is an important dietary component. Agricultural wastes, cheap carbon sources- which are rich and have high energy, can be used for producing the value added bioprotein. A lab scale study was carried out to optimize the media composition for bioprotein production from a cheaper carbon source - wheat flour using potential strain, which was selected earlier by screening different microorganisms. The performance of the selected strain was enhanced by media optimization with varied substrate concentration, nitrogen sources and nutrient supplementation according to the central composite design from STATISTICA software. Statistical optimization was carried out to evaluate the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum biomass produced was 21.89 g/L with optimum fermentation conditions of wheat flour (4 g/L), nitrogen concentration (0.5 g/L), nutrient concentration (0.1 g/L), and four days of fermentation

Transient Accelerated Expansion and Double Quintessence

We consider Double Quintessence models for which the Dark Energy sector consists of two coupled scalar fields. We study in particular the possibility to have a transient acceleration in these models. In both Double Quintessence models studied here, it is shown that if acceleration occurs, it is necessarily transient. We consider also the possibility to have transient acceleration in two one-field models, the Albrecht-Skordis model and the pure exponential. Using separate conservative constraints (marginalizing over the other parameters) on the effective equation of state $w_{eff}$, the relative density of the Dark Energy $\Omega_{Q,0}$ and the present age of the universe, we construct scenarios with a transient acceleration that has already ended at the present time, and even with no acceleration at all, but a less conservative analysis using the CMB data rules out the last possibility. The scenario with a transient acceleration ended by today, can be implemented for the range of cosmological parameters $\Omega_{m,0}\gtrsim 0.35$ and $h\lesssim 0.68$.Comment: Version accepted in Phys. Rev. D, 22 pages, 10 figures, 4 table

Accretions of Various Types of Dark Energies onto Morris-Thorne Wormhole

In this work, we have studied accretion of the dark energies onto Morris-Thorne wormhole. For quintessence like dark energy, the mass of the wormhole decreases and phantom like dark energy, the mass of wormhole increases. We have assumed two types of dark energy like variable modified Chaplygin gas (VMCG) and generalized cosmic Chaplygin gas (GCCG). We have found the expression of wormhole mass in both cases. We have found the mass of the wormhole at late universe and this is finite. For our choices the parameters and the function $B(a)$, these models generate only quintessence dark energy (not phantom) and so wormhole mass decreases during evolution of the universe. Next we have assumed 5 kinds of parametrizations of well known dark energy models. These models generate both quintessence and phantom scenarios. So if these dark energies accrete onto the wormhole, then for quintessence stage, wormhole mass decreases upto a certain value (finite value) and then again increases to infinite value for phantom stage during whole evolution of the universe. We also shown these results graphically.Comment: 9 pages, 7 figures. arXiv admin note: text overlap with arXiv:1112.615

Effect of Severe Protein-Energy Malnutrition on Circulating Thyroid Hormones

Protein energy malnutrition (PEM) is one of the most common health problems among Bangladeshi children. PEM is known to induce a wide variety of metabolic disorders and some of which may be mediated through alteration of endocrine functions. Both short-term and long-term alterations in nutritional state affect various aspects of thyroid hormone economy, especially peripheral hormone metabolism. Chronic malnutrition is associated with a decreased serum T3 concentration. Serum T4 levels also tend to be slightly decreased because of a modest decrease in iodothyronine binding protein. TSH concentrations and their response to exogenous TRH are usually normal. To identify the effects of severe protein energy malnutrition on circulating iodothyronines especially circulating T3 & T4 and to determine the level of TSH in severe PEM. To compare the levels of thyroid hormones before and after recovery from severe PEM and to identify any correlation with mortality and morbidity. A prospective cross-sectional comparative study was performed in Nutrition block, Department of Pediatrics, Chittagong Medical College Hospital from 01 Dec 2007 to 30 Nov 2008. Patient admitted to nutrition block with severe PEM were included in the study. The levels of T4, T3 and TSH measured by radioimmunoassay (RIA) method. TSH was measured by using Immunoradiometric Assay Kit, IMK-432 produced by Beijing Atom Hitech Co. Ltd, China. T3 and T4 were measured by using Radioimmunoassay Kit (PR), IMK-422 and IMK-419 respectively produced by Beijing Atom Hitech Co. Ltd, China. Data were presented as the percentage of total number of observation. SPSS- Version 15.0 was used for the analysis of data. Student’s t-test, Z-test, χ-square test and Pearson’s correlation test were used for statistical significance. ‘p’ value of < 0.05 were used as the  minimum level of significance. The effect of protein energy malnutrition (PEM) in the children on serum levels of total thyroxine (TT4), total triiodothyronine (TT3) and thyrotropin (TSH) were evaluated. There were 50 children aged 6 to 60 months in the malnutrition group and 22 healthy age and sex matched controls. Serum TT4 and TT3 were all reduced in the malnutrition group. This decrease in TT3 was more significant (p<0.001) in severe malnutrition than in mild PEM. Serum TSH levels in the malnutrition and control groups were similar. These results suggest that the children remained euthyroid and represent an adaptive response to protein energy malnutrition. The results of the above mentioned studies clearly demonstrate that thyroid functions are adversely affected in severe PEM. This was evidenced by reductions in T3 & T4 levels in comparison to control group. Keywords: Protein Energy Malnutrition; Thyroxine; Triiodothyronine; Thyrotropin

Independent higher education educators in England: Tutors behavioural characteristics preferred by mature students on business management courses

This research study focuses on identifying the behavioral characteristics desired by mature students from their educators/lecturers/tutors in an Independent Higher Education provider within the UK. The study utilises a mixed-method approach, employing a nonexperimental and sequential explanatory design consisting of two phases. The first phase involves a questionnaire survey, while the second phase comprises semi-structured interviews with the students, aiming to gather both detailed and general insights into the students’ perspectives on the expected behavioral characteristics of their educators. The findings of this study reveal both commonalities and differences in the attributes of lecturers as identified in the quantitative and qualitative findings. In both sets of findings, it is evident that students prefer personalised learning experiences, with an emphasis on lecturers recognising their unique strengths, valuing individuality and providing positive feedback. Additionally, the qualitative findings highlight the significance of patience, empathy, and problem-centered teaching as highly valued traits of a lecturer according to the students. This research contributes to the existing body of knowledge by addressing the complexities involved in educating mature students within the UK Higher Education sector. It emphasises the importance for Higher Education practitioners to comprehend the expected behavioral characteristics of these mature students from their educators. The study also highlights the scarcity of research in this area, as existing literature on adult education and andragogy is often generic and independent of specific contexts

Reconstructing generalized ghost condensate model with dynamical dark energy parametrizations and observational datasets

Observations of high-redshift supernovae indicate that the universe is accelerating at the present stage, and we refer to the cause for this cosmic acceleration as ``dark energy''. In particular, the analysis of current data of type Ia supernovae (SNIa), cosmic large-scale structure (LSS), and the cosmic microwave background (CMB) anisotropy implies that, with some possibility, the equation-of-state parameter of dark energy may cross the cosmological-constant boundary ($w=-1$) during the recent evolution stage. The model of ``quintom'' has been proposed to describe this $w=-1$ crossing behavior for dark energy. As a single-real-scalar-field model of dark energy, the generalized ghost condensate model provides us with a successful mechanism for realizing the quintom-like behavior. In this paper, we reconstruct the generalized ghost condensate model in the light of three forms of parametrization for dynamical dark energy, with the best-fit results of up-to-date observational data.Comment: 8 pages, 3 figures; references added; accepted for publication in Mod. Phys. Lett.

Effects of variable chemical reaction and variable electric conductivity on free convective heat and mass transfer flow along an inclined stretching sheet with variable heat and mass fluxes under the influence of Dufour and Soret effects, Nonlinear Analys

Abstract. This paper deals with the effects of variable chemical reaction and variable electric conductivity on free convection and mass transfer flow of a viscous, incompressible and electrically conducting fluid over an inclined stretching sheet with variable heat and mass fluxes under the influence of Dufour and Soret effects. The non-linear boundary layer equations with boundary conditions are transferred into a system of non-linear ordinary differential equations using an established similarity transformation. These non-linear and locally-similar ordinary differential equations are solved numerically by applying Nachtsheim-Swigert shooting iteration technique with sixth-order Runge-Kutta integration scheme. Comparison with previously published work is obtained and excellent agreement is found. The effects of various parameters on the dimensionless velocity, temperature and concentration profiles as well as the local skin-friction coefficient, heat and mass transfer rate from the stretching sheet to the surrounding fluid are presented graphically and in tabulated form for a hydrogen-air mixture. The numerical results showed that chemical reaction parameter K, order of reaction n, Dufour number Df , Soret number Sr and heat (or mass) flux parameter r play a crucial role in the solutions

New Physics and the Landau Pole

In scalar field theories the Landau pole is an ultraviolet singularity in the running coupling constant that indicates a mass scale at which the theory breaks down and new physics must intervene. However, new physics at the pole will in general affect the running of the low energy coupling constant, which will in turn affect the location of the pole and the related upper limit (``triviality'' bound) on the low energy coupling constant. If the new physics is strongly coupled to the scalar fields these effects can be significant even though they are power suppressed. We explore the possible range of such effects by deriving the one loop renormalization group equations for an effective scalar field theory with a dimension 6 operator representing the low energy effects of the new physics. As an independent check we also consider a renormalizable model of the high-scale physics constructed so that its low energy limit coincides with the effective theory.Comment: 26 pages, 5 figure

Development of an Advanced Engineering Polymer from the Modification of Nylon 66 by e-Beam Irradiation

When Nylon 66 was irradiated by an optimum dose of e-beam in presence of polyurethane as impact modifierin combination with triallyl isocyanurate as cross-linker, a superior performance was observed for the irradiatednylon 66. Significant improvement of properties, such as hardness, tensile strength, flexural modulus and impactstrength was obtained on radiation processing of nylon 66 by e-beam. More interestingly, percent water absorptionof such irradiated nylon 66 was reduced substantially. Improvement of mechanical properties and reduction of waterabsorption of irradiated nylon 66 were due to the cross-linking of the polymer system. Increase of cross-linkingwith dose of e-beam was verified by the increased gel content at higher doses. Irradiated nylon 66 showed betterdimensional stability than those achieved with pristine nylon 66. The increase in dimensional stability may beattributed to reduction in crystallinity with increasing dose of e-beam as revealed by DSC studies.Defence Science Journal, Vol. 64, No. 3, May 2014, pp. 281-289, DOI:http://dx.doi.org/10.14429/dsj.64.732