Symmetry analysis for steady boundary-layer stagnation-point flow of Rivlin–Ericksen fluid of second grade subject to suction

An analysis for the steady two-dimensional boundary-layer stagnation-point flow of Rivlin–Ericksen fluid of second grade with a uniform suction is carried out via symmetry analysis. By employing Lie-group method to the given system of nonlinear partial differential equations, the symmetries of the equations are determined. Using these symmetries, the solution of the given equations is found. The effect of the viscoelastic parameter k and the suction parameter R on the tangential and normal velocities, temperature profiles, heat transfer coefficient and the wall shear stress, have been studied. Also, the effect of the Prandtl number Pr on the temperature and the heat transfer coefficient has been studied

Group theoretic approach for solving the problem of diffusion of a drug through a thin membrane

AbstractThe transformation group theoretic approach is applied to study the diffusion process of a drug through a skin-like membrane which tends to partially absorb the drug. Two cases are considered for the diffusion coefficient. The application of one parameter group reduces the number of independent variables by one, and consequently the partial differential equation governing the diffusion process with the boundary and initial conditions is transformed into an ordinary differential equation with the corresponding conditions. The obtained differential equation is solved numerically using the shooting method, and the results are illustrated graphically and in tables

Predicting Intermediate Storage Performance for Workflow Applications

Configuring a storage system to better serve an application is a challenging task complicated by a multidimensional, discrete configuration space and the high cost of space exploration (e.g., by running the application with different storage configurations). To enable selecting the best configuration in a reasonable time, we design an end-to-end performance prediction mechanism that estimates the turn-around time of an application using storage system under a given configuration. This approach focuses on a generic object-based storage system design, supports exploring the impact of optimizations targeting workflow applications (e.g., various data placement schemes) in addition to other, more traditional, configuration knobs (e.g., stripe size or replication level), and models the system operation at data-chunk and control message level. This paper presents our experience to date with designing and using this prediction mechanism. We evaluate this mechanism using micro- as well as synthetic benchmarks mimicking real workflow applications, and a real application.. A preliminary evaluation shows that we are on a good track to meet our objectives: it can scale to model a workflow application run on an entire cluster while offering an over 200x speedup factor (normalized by resource) compared to running the actual application, and can achieve, in the limited number of scenarios we study, a prediction accuracy that enables identifying the best storage system configuration

Optimization of exopolysaccharide production by pleurotus ostreatus using diffrent cultivation strategies

Pleurotus ostreatus or known as oyster mushroom was regarded as one of the most cultivated mushroom around the world. One of the qualities it has is it able to produced exopolysaccharide called pleuran which secreted into the medium during submerged fermentation. The polysaccharide composed mainly of ß-(1/3)-D glucose and ß-(1/6)-D glucose linked by glycosidic bond. It has molecular weight of 2.4 X 104 Da with molecular formula of (C6H10O5)x The importance of pleuran is that it has the immunomodulatory properties that associated in triggering our immune system response. Nowadays, submerged fermentation is considered as the best method in cultivation this kind of mushroom. However, the production process of this kind of mushroom and its exopolysaccharide production especially in term of medium component is still unclear. In this research, the objectives were to optimize the medium composition and to find the optimum carbon to nitrogen (C: N) ratio for high exopolysaccharide production. Eight different media was screened and followed by factor by factor optimization of the medium component. The factors that been studied were ideal concentration of glucose, yeast extract, ammonium sulfate and dipotassium phosphate. Media number six which contain glucose 60.0 g L-1, yeast extract 2.0 g L-1, (NH4)2SO4 5.0 g L-1, MgSO4.7H2O 0.2 g L-1, K2HPO4 1.0 g L-1 was selected as best media production for P. ostreatus cultivation . The experiment then was further with different concentration of each component in the medium six excluding magnesium sulfate heptahydrate which maintained at 0.2 g L-1 throughout all the experiment stage. The range concentration for glucose, yeast extract, ammonium sulfate and dipotassium phosphate was setup between 0 – 120 g L-1, 0 – 4 g L-1, 0 – 5 g L-1 and 0 – 2 g L-1 respectively. In order to get the best C: N ratio for highest exopolysaccharide production, eleven ratio of carbon to nitrogen was experimented ranging from 15:1 to 65:1.Result shown that the optimum concentration for glucose, yeast extract, ammonium sulfate and dipotassium phosphate was 80.0, 4.0, 2.5 and 1.0 g L-1 respectively whiles the optimal C: N ratio recorded was 40: 1. The optimized medium also produced 2.83 g L-1 of exopolysaccharide increasingly up to 49 % when compared with un-optimized medium which only produced 1.9 g L-1 of exopolysaccharide

Medium Optimization for Xylanase Production by Recombinant Escherichia coli B24

473-478Interest in xylanase enzyme application has led to production of xylanase from recombinant Escherichia coli B24, which is an economic alternative towards higher productivity. Recombinant E. coli used in this study is a ubiquitous bacterium containing xylanase encoding gene from Bacillus halodurans. We investigated xylanase production by recombinant E. coli using classical medium optimization. Six fermentation media had been chosen from literature for xylanase production. Afterwards, the most suitable medium was further optimized by varying the key nutrients. The final optimized cultivation medium consisted of (g.L-1): glucose, 2.5; NH4Cl, 0.4; KH2PO4, 3.0; Na2HPO4, 6.0; MgSO4.7H2O, 1.0. After medium optimization, maximal volumetric xylanase production (600.25 U.mL-1) increased by about 115.22% from the initial un-optimized medium (278.9 U.mL-1)

Medium optimization for xylanase production by recombinant escherichia coli B24

Interest in xylanase enzyme application has led to production of xylanase from recombinant Escherichia coli B24, which is an economic alternative towards higher productivity. Recombinant E. coli used in this study is a ubiquitous bacterium containing xylanase encoding gene from Bacillus halodurans. We investigated xylanase production by recombinant E. coli using classical medium optimization. Six fermentation media had been chosen from literature for xylanase production. Afterwards, the most suitable medium was further optimized by varying the key nutrients. The final optimized cultivation medium consisted of (g.L-1): glucose, 2.5; NH4Cl, 0.4; KH2PO4, 3.0; Na2HPO4, 6.0; MgSO4.7H2O, 1.0. After medium optimization, maximal volumetric xylanase production (600.25 U.mL-1) increased by about 115.22% from the initial unoptimized medium (278.9 U.mL-1)

Tongue control and its implication in pronunciation training

International audiencePronunciation training based on speech production techniques illustrating tongue movements is gaining popularity. However, there is not sufficient evidence that learners can imitate some tongue animation. In this paper, we argue that although controlling tongue movement related to speech is not such an easy task, training with visual feedback improves its control. We investigated human awareness of controlling their tongue body gestures. In a first experiment, participants were asked to perform some tongue movements composed of two sets of gestures. This task was evaluated by observing ultrasound imaging of the tongue recorded during the experiment. No feedback was provided. In a second experiment, a short session of training was added where participants can observe ultrasound imaging in real time of their own tongue movements. The goal was to increase their awareness of their tongue gestures. A pretest and posttest were carried out without any feedback. The results suggest that without a priori knowledge, it is not easy to finely control tongue body gestures. The second experiment showed that we gained in performance after a short training session and this suggests that providing visual feedback, even a short one, improves tongue gesture awareness

Halotolerant microbial consortia for sustainable mitigation of salinity stress, growth promotion, and mineral uptake in tomato plants and soil nutrient enrichment

Salinity significantly impacts the growth, development, and reproductive biology of various crops such as vegetables. The cultivable area is reduced due to the accumulation of salts and chemicals currently in use and is not amenable to a large extent to avoid such abiotic stress factors. The addition of microbes enriches the soil without any adverse effects. The effects of microbial consortia comprising Bacillus sp., Delftia sp., Enterobacter sp., Achromobacter sp., was evaluated on the growth and mineral uptake in tomatoes (Solanum Lycopersicum L.) under salt stress and normal soil conditions. Salinity treatments comprising Ec 0, 2, 5, and 8 dS/m were established by mixing soil with seawater until the desired Ec was achieved. The seedlings were transplanted in the pots of the respective pH and were inoculated with microbial consortia. After sufficient growth, these seedlings were transplanted in soil seedling trays. The measurement of soil minerals such as Na, K, Ca, Mg, Cu, Mn, and pH and the Ec were evaluated and compared with the control 0 days, 15 days, and 35 days after inoculation. The results were found to be non-significant for the soil parameters. In the uninoculated seedlings’ (control) seedling trays, salt treatment significantly affected leaf, shoot, root dry weight, shoot height, number of secondary roots, chlorophyll, and mineral contents. While bacterized seedlings sown under saline soil significantly increased leaf (105.17%), shoot (105.62%), root (109.06%) dry weight, leaf number (75.68%), shoot length (92.95%), root length (146.14%), secondary roots (91.23%), and chlorophyll content (−61.49%) as compared to the control (without consortia). The Na and K intake were higher even in the presence of the microbes, but the beneficial effect of the microbe helps plants sustain in the saline environment. The inoculation of microbial consortia produced more secondary roots, which accumulate more minerals and transport substances to the different parts of the plant; thus, it produced higher biomass and growth. Results of the present study revealed that the treatment with microbial consortia could alleviate the deleterious effects of salinity stress and improve the growth of tomato plants under salinity stress. Microbial consortia appear to be the best alternative and cost-effective and sustainable approach for managing soil salinity and improving plant growth under salt stress conditions