Numerical simulation of a low aspect ratio wing at low Reynolds number

In this work the numerical simulation of aerodynamic performance of low aspect ratio wings at low Reynolds numbers applicable to micro aerial vehicle is carried out. Commercial software STAR-CCM+ was used to simulate the flow and predict the aerodynamics performances of the low aspect ratio wing. Results were presented in terms of pressure coefficient distribution, flow visualization, lift and drag coefficients for angle of attacks ranging from 0˚ to 18˚ and Reynolds numbers ranging from 104 to 105 Keywords: Rectangular planform wing; Tip vortices; Flow separation . The results showed that, for rectangular planform wing, the distribution of the pressure is dominated by vortices. The results also showed the formation of tip vortices at lower Reynolds number for rectangular wing configuration. It is evident from the results that the type of wing configurations plays a very important role in delaying or preventing the flow separation

PREPARATION AND EVALUATION OF VITAMIN E ADJUVANTED OIL EMULSIFIED INFECTIOUS BRONCHITIS EXPERIMENTAL VACCINE

The present study was conducted to prepare oil emulsified (OE) infectious bronchitis (IB) experimental vaccines. The vaccines were prepared using the vaccinal strain H-120 Infectious Bonchitis virus (IBV). The virus was cultivated in 9-day old embryonated eggs via allantoic cavity route. Allantoic-amniotic fluid (AAF) was collected and inactivated with formalin @ 0.12%. Water in oil emulsion was prepared by adding one part of AAF to four parts of mineral oil containing water phase (Tween 80) and oil phase (Span 80) surfactants. Hydrophile lypohile balance (HLB) of the emulsion was maintained at 7.0. Two oil emulsified experimental vaccines were prepared. Vaccine-I was prepared without vitamin E and Vaccine-II with vitamin E (300 mg/ml). A total of 120 day-old broiler breeder chickens were divided into 4 groups, A, B, C, and D, each having 30 birds. At the age of 21 days, experimental Vaccine-I, experimental vaccine-II and commercial IB killed (H-120) vaccine were inoculated @ 0.5 ml in the birds of groups A, B and C, respectively. Group D was maintained as nonvaccinated control. Efficacy of the vaccines was evaluated on the basis of humoral immune response (haemagglutination inhibition antibody titres) against IB in the four groups. The seven weeks cumulative mean antibody titres (CMT) of each group were calculated. The highest CMT was observed in group B (130), followed by group C (69), group A (58) and group D (17). Statistical analysis showed that haemagglutination inhibition (HI) antibody titres in group B (vaccine- II) were significantly higher than those of groups A, B and C (P< 0.05)

Comparison of high-order accurate schemes for solving the nonlinear viscous burgers equation

In this paper, a comparison between higher order schemes has been performed in terms of numerical accuracy. Four finite difference schemes, the explicit fourth-order compact Pade scheme, the implicit fourth-order Pade scheme, flowfield dependent variation (FDV) method and high order compact flowfie ld dependent variation (HOC-FDV) scheme are tes ted. The FDV scheme is used for time disc retization and the fourth-order compact Pade scheme is used for spatial derivatives. The solution procedures consist of a number of tri-diagonal matrix operations and produce an efficient solver. The comparisons are performed using one dimensional nonlinear viscous Burgers equation to demonstrate the accuracy and the convergence characteristics of the high-resolution schemes. The numerical results show that HOC-FDV is highly accurate in comparison with analytical and with other higher order schemes

Response of salt stressed okra (Abelmoschus esculentus Moench) plants to foliar-applied glycine betaine and glycine betaine containing sugarbeet extract

AbstractThe present experiment was aimed at examining the ameliorative effect of foliar-applied glycine betaine (50mM GB) and glycine betaine containing sugarbeet extract (50mM GB) on various physiological and biochemical attributes of okra plants under salt stress. The experiment comprised of two okra cultivars (Arka-anamika and Sabaz-pari), two salt levels (0 and 150mM NaCl), and two GB sources (synthetic pure GB and sugarbeet extract) arranged in four replicates. Salt stress significantly suppressed the biomass production, yield, and different gas exchange attributes (A, E, Ci, and gs). Glycine betaine and proline contents in leaves, and Na+ and Cl− contents in both leaves and roots increased, while K+ and Ca2+ contents and K+/Na+ ratios decreased significantly. Foliar application of both pure GB and sugarbeet extract significantly reduced the adverse effects of salt stress on plant biomass production, plant yield, various gas exchange characteristics and leaf K+, Ca2+, Cl− and Na+ contents. However, GB and sugarbeet extract showed differential effects on A, gs, E, Ci, Ci/Ca ratio, leaf K+, Ca2+, and Cl− contents, and K+/Na+ ratio. Pure GB proved better than the sugarbeet extract in improving growth, while the reverse was true for plant yield under salt stress. However, with respect to different gas exchange attributes both GB and sugarbeet extract were found to be equally effective in reducing the adverse effects of salt stress on these photosynthetic attributes. Foliar-applied sugarbeet extract was found to be more effective as compared to pure GB in reducing the adverse effects of salt stress on K+ and Ca2+ uptake and K+/Na+ ratio in shoot and root of both okra cultivars. Thus, sugarbeet extract could be used to induce salt tolerance in economically important crop plants

Biogenic volatile compounds of activated sludge and their application for metal bioremediation

Heavy metals pollution is nowadays one of the most important environmental concerns. This paper illustrates the employment of the biogenic volatile compounds generated during the aerobic growth of activated sludge on raw domestic wastewater for heavy metals removal. Most of the tested metals even as individual or mixed metal species (Co, Cu, Cd, Fe, Hg, Ni, Mn, Pb and Zn) were potentially transformed into insoluble precipitates and then separated out of their solutions. The Fourier-transform infrared (FTIR) analysis has identified some organosulfur groups (thiol, disulfide and thiocarbonyl), in addition to amine group in the metal precipitates. This study highlighted the application of the microbial volatile metabolites for heavy metals bioremediation in a powerful, cost effective and eco-friendly bioprocess.Key words: Application, activated sludge, biogas, metals, bio-precipitatio

Performance evaluation of Cu-Ni 90/10 alloyed structures exposed to various seawater compositions and their remaining service life estimation

The Cu-Ni 90/10 alloy is extensively used in seawater applications mainly because of its excellent heat transferability, resistance toward corrosion and marine fouling. The corrosion resistance of Cu-Ni 90/10 has been found to be far superior in open natural seawater, however, several premature failures have often been reported during their exposure in the pollutant-rich seawater typically found near harbours, jetties and coastlines. This paper investigates the corrosion behaviour of Cu-Ni 90/10 alloyed coupons exposed to natural seawater, and pollutant-rich harbour seawater in a submerged position. Moreover, this research also investigates the corrosion mechanism on marine heat exchanger tubes of material that failed prematurely while operating in similar seawater compositions. The field experimental results for short-term corrosion results from coupons, and the long-term corrosion results from heat exchanger tubes have been evaluated, to formulate a relationship and corrosion modelling

The Efficiency of Gas-Kinetic BGK scheme for solving 2-d compressible inviscid regular shock reflection problem

In this paper, the 1st and 2nd order gas-kinetic BGK scheme is developed and tested for its ability in solving the two-dimensional compressible inviscid flow fields. The BGK (Bhatnagar-Gross-Krook) scheme uses the collisional Boltzmann equation as the governing equation for flow evolutions. Second-order BGK scheme is also developed for flow simulation. This is achieved by means of reconstructing the initial data via MUSCL (Monotone Upstream-Centered Schemes for Conservation Laws) method. In addition, a multisage TVD (Total Variation Diminishing) Runge-Kutta method is employed for the time integration of the finite volume gas-kinetic scheme. A typical two-dimensional regular reflection of an oblique shock wave from a solid surface is chosen for testing the accuracy and robustness of the BGK scheme. The computational results are validated against the numerical results of Roe’s scheme

Characteristics of Socio-Alive Building: the case of Bahrain city center

Socio-Alive Building is Architecture where people enjoy being around to live within its environment and want to come back after leaving. This paper discusses the terminology of Socio-Alive Building and identifies the building characteristics which make a building social and alive. The main aim of this paper is to discuss the concept of alive-socio building as an approach to keep the building alive and have social role through the consideration of characteristics of socio-alive building. The paper begins by introducing the definitions of Socio-Alive Building and then discusses the characteristics of Socio-Alive Building to construct a theoretical background, then reports the outcomes of a survey in Bahrain to find out perceptions of people of Bahrain toward building characteristics, which could produce socio-alive build environments. A people’s survey concluded significance scale factors of building characteristics that achieve the sociality and alive of the building in Bahrain which were used to evaluate Bahrain City Center. The paper offers ten compromised building characteristics that can produce Socio-Alive with certain significance scale of each. The authors argue that these could be considered during design process to produce socio-alive buildings