215 research outputs found

    A modified fifth-order WENO scheme for hyperbolic conservation laws

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    This paper deals with a new fifth-order weighted essentially non-oscillatory (WENO) scheme improving the WENO-NS and WENO-P methods which are introduced in Ha et al. J. Comput. Phys. (2013) and Kim et al., J. Sci. Comput. (2016) respectively. These two schemes provide the fifth-order accuracy at the critical points where the first derivatives vanish but the second derivatives are non-zero. In this paper, we have presented a scheme by defining a new global-smoothness indicator which shows an improved behavior over the solution to the WENO-NS and WENO-P schemes and the proposed scheme attains optimal approximation order, even at the critical points where the first and second derivatives vanish but the third derivatives are non-zero.Comment: 23 pages, 14 figure

    Investigating roles for RNA turnover processes in cell signaling through Drosophila melanogaster genetic mosaics

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    The process of cell signaling is vital in organisms for proper development as it determines the fate and function of cells. This process is highly regulated by myriad interactions between signaling pathway components and gene expression mechanisms. RNA turnover is a type of RNA processing that degrades RNA. It plays an essential role in homeostasis and environmental changes; however, its influence on signaling pathways is currently unknown. In the present study, the effect of RNA turnover processes on cell signaling was analyzed using the genetic mosaics in Drosophila melanogaster. Fly mosaics were created by breeding RNAi lines targeting cellular ribonucleases under control of the UAS promoter with a fly line expressing GAL4 in the notum region of imaginal wing discs. Cell signaling phenotypes were analyzed in 3rd instar larva utilizing immunohistochemistry. It was observed that knockdown of RNA turnover genes resulted in substantial changes in signaling pathway proteins as well as evidence of hyperproliferation, apoptosis, and reduced proliferation. Morphologically, it was observed that the knockdown of RNA turnover genes resulted in thinner and shorter sensory notum and bristles in Drosophila adults. This indicates that RNA turnover influences developmental signaling pathways and may be an important mechanism in gene regulatory networks. Exercising control of developmental signaling pathways could be applied in therapeutics for c

    Arc length based WENO scheme for Hamilton-Jacobi Equations

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    In this article, novel smoothness indicators are presented for calculating the nonlinear weights of weighted essentially non-oscillatory scheme to approximate the viscosity numerical solutions of Hamilton-Jacobi equations. These novel smoothness indicators are constructed from the derivatives of reconstructed polynomials over each sub-stencil. The constructed smoothness indicators measure the arc-length of the reconstructed polynomials so that the new nonlinear weights could get less absolute truncation error and gives a high-resolution numerical solution. Extensive numerical tests are conducted and presented to show the performance capability and the numerical accuracy of the proposed scheme with the comparison to the classical WENO scheme.Comment: 14 pages, 9 figure

    A peptidase activity exhibited by human serum pseudocholinesterase

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    The identity of a peptidase activity with human serum pseudocholinesterase (PsChE) purified to apparent homogeneity was demonstrated by (a) co-elution of both peptidase and PsChE activities from procainamide-Sepharose and concanavalin-A-Sepharose affinity chromatographic columns; (b) comigration on polyacryl-amide gel electrophoresis; (c) co-elution on Sephadex G-200 gel filtration and (d) coprecipitation at different dilutions of an antibody raised against purified PsChE. The purified enzyme showed a single protein band on gel electrophoresis under non-denaturing conditions. SDS gel electrophoresis under reducing conditions, followed by silver staining, also gave a single protein band (Mr∼90000). Peptidase activity using different peptides showed the release of C-terminal amino acids. Blocking the carboxy terminal by an amide or ester group did not prevent the hydrolysis of peptides. There was no evidence for release of N-terminal amino acids. Potent anionic or esteratic site inhibitors of PsChE, such as eserine sulphate, neostigmine, procainamide. ethopropazine, imipramine, diisopropylfluorophosphate, tetra-isopropylpyrophosphoramide and phenyl boronic acid, did not inhibit the peptidase activity. An anionic site inhibitor (neostigmine or eserine) in combination with an esteratic site inhibitor (diisopropylfluorophosphate) also did not inhibit the peptidase. However, the choline esters (acetylcholine, butyrylcholine, propionylcholine, benzoylcholine and succinylcholine) markedly inhibited the peptidase activity in parallel to PsChE. Choline alone or in combination with acetate, butyrate, propionate. benzoate or succinate did not significantly inhibit the peptidase activity. It appeared that inhibitor compounds which bind to both the anionic and esteratic sites simultaneously (like the substrate analogues choline esters) could inhibit the peptidase activity possibly through conformational changes affecting a peptidase domain

    Numerical schemes for a class of nonlocal conservation laws: a general approach

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    In this work we present a rather general approach to approximate the solutions of nonlocal conservation laws. Thereby, we approximate in a first step the nonlocal term with an appropriate quadrature rule applied to the spatial discretization. Then, we apply a numerical flux function on the reduced problem. We present explicit conditions which such a numerical flux function needs to fulfill. These conditions guarantee the convergence to the weak entropy solution of the considered model class. Numerical examples validate our theoretical findings and demonstrate that the approach can be applied to further nonlocal problems

    Experimental Studies on Sugar Cane Bagasse Ash based Geomaterials

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    oai:ojs2.www.ijemr.net:article/1Use of conventional materials is increasing day by day due to rapid infrastructural growth which increases the cost of materials and increases the cost of construction. Hence utilization of Sugar cane bagasse ash waste materials without causing threat to environment solves the problems of disposal and also can provide economical materials. In this study glass fiber, sugarcane bagasse ash and blast furnace slag were used and cement used for binding purpose. Different mix ratio was prepared to understand the effect of addition of glass fibre on sugar cane bagasse ash based materials under compressive loading. The mix ratio was taken 0.2 to 1.0% for the research work. Blast furnace slag was added 10% to weight of sugar cane bagasse ash. The sample were tested for compressive loading for 7, 14, 28 days respectively. The density is most important parameter of materials. It was observed that the density of materials significantly influences with addition of glass fibre. The density of materials decreases with percentage of glass fiber increase. The density of materials varies between 901.1 kg/m3 to 741.10kg/m3The compressive strength also significantly affected by percentages of glass fibre. The compressive strength ranging 82 kPa to 798 kPa.The compressive strength increases up to certain mix ratio then decrease continuously. The stiffness of sugar cane bagasse ash specimens reinforced with glass fiber at cement 20% more than 15% and 10%.The stiffness also increase with the curing period. The maximum load was observed at 0.6% mix ratio. The stress strain behavior was observed to be nonlinear

    Utilization of EPS Beats and Polypropylene Fiber in Controlled Low Strength Material

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    Controlled low-strength material (CLSM) is a self-levelling cementitious material. It is not concrete nor soil-cement, however, it possesses properties similar to both. CLSM is widely used as a replacement for soil-cement material in many geotechnical applications such as structural backfill, pipeline beddings, void fill, pavement bases and bridge approaches. This paper study potential possibility of polypropylene fiber in CLSM. Harden and fresh properties compressive strength , flowability  and density for the proposed CLSM were investigated. This CLSM mix design with different percentage of polypropylene fiber and pond ash, cement and water. EPS beats and polypropylene add 0 %, 0.5%, 1.0% and 1.5% of total weight is added in CLSM MIx. Results show that the CLSM incorporating EPS beats and polypropylene satisfies compressive strength requirement as per the requirements of ACI committee 229. polypropylene  decreases the flowability of CLSM mix and at the same tine by adding EPS beats the density of CLSM mix are reduce which become lightweight CLSM mix. from this it can conclude that polypropylene fibers is less effective in CLSM mix and EPS beats make CLSM mix lightweight which create lightweight CLSM mix applicable for filling application

    Evaluation and Mix Design for Ternary Blended High Strength Concrete

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    AbstractConcrete has been the most widely used construction material for several years. Though conventional concrete (CC) performs very well under normal conditions, in special situations a very high compressive strength of concrete together with sustainability to aggressive environments is necessary. Hence, higher compressive strength of range more than 60MPa is essential. So far, concrete mixes were designed only for strength and workability requirements. For the performance of long satisfactory life, the designed mixes should be checked and proved for their durability properties such as low permeability, high corrosion resistance, freezing and thawing resistance, fire resistance etc. This necessitates a detailed study on High strength concrete (HSC). This paper formulates a simplified mix design procedure for HSC by combining BIS and ACI code methods of mix design along with available literatures on HSC. Based on the above procedure M60 mix of ternary blended high strength concrete with different percentage replacement of cement by metakaolin (MK) and redmud (RM) is arrived at. These HSC mixes are tested experimentally for compression, split tension, flexure and workability. The performance of the designed mixes is very good and the results are reported in this paper
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