85 research outputs found

    Semi-automatic determination of elemental sulphur in rubber

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    Electro-active elemental sulphur dissolved in hydrazine hydrate solvent was studied by d.c. polarography, cyclic voltammetry and millicoulometry in sodium acetate, ammonium tartrate and sodium phosphate buffers in an aqueous medium. The method, which uses a mercury electrode, is highly sensitive with less interference than other polarographic methods. The method was extended to the determination of sulphur in pressure rubber tubing. This paper also suggests a mechanism of electrode reaction

    Bayesian learning scheme for sparse DOA estimation based on maximum-a-posteriori of hyperparameters

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    In this paper, the problem of direction of arrival estimation is addressed by employing Bayesian learning technique in sparse domain. This paper deals with the inference of sparse Bayesian learning (SBL) for both single measurement vector (SMV) and multiple measurement vector (MMV) and its applicability to estimate the arriving signal’s direction at the receiving antenna array; particularly considered to be a uniform linear array. We also derive the hyperparameter updating equations by maximizing the posterior of hyperparameters and exhibit the results for nonzero hyperprior scalars. The results presented in this paper, shows that the resolution and speed of the proposed algorithm is comparatively improved with almost zero failure rate and minimum mean square error of signal’s direction estimate

    Simple High-performance Liquid Chromatographic Method for the Determination of Acyclovir in Pharmaceuticals

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    An assay method for the determination of acyclovir from pharmaceutical preparations has been developed for assessment of product quality utilising high-performance liquid chromatography. The chromatographic conditions comprised a reversed-phase C18 column (250×4.6 mm i.d.) with a mobile phase of acetonitrile-20 mmol l−1 aqueous ammonium acetate buffer of pH 4.5 (40:60). The flow rate was 0.8 ml min−1 and UV detection was used at 250 nm. Calibration graph was linear in the range 1.98–59.4 μg ml−1. The method has been validated according to current guidelines including assay of pharmacopoeial standard tablets. Recoveries ranged from 96.64 to 99.53%. The exipients present in the tablets did not interfere with the method

    Molecular detection and characterization of phytoplasma associated with China aster (Callistephus chinensis) phyllody in India

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    China aster (Callistephus chinensis L.) is one of the most popular annual flowering plant grown through-out the world. Phyllody disease of China aster is a phytoplasma associated disease that induces severe economic losses. Phytoplasmal disease in China aster was assessed for phytoplasma by direct polymerase chain reaction primed by using phytoplasma universal primer pairs PI/P7. A 1.8 Kb DNA fragments encoding the portion of phyto-plasma 16SrDNA amplified by PCR was cloned and sequenced. Sequencing of the PCR product and BLAST analy-sis indicated that China aster phyllody phytoplasma strain shared maximum sequence identity (99%) with strains of Peanut Witches’ broom (16SrII) phytoplasma group. Phylogenetic relationship of 16SrDNA sequence of China aster phyllody phytoplasma strain in the present study confirmed association of Peanut Witches’ broom (16SrII) group of phytoplasmas with China aster phyllody disease in India

    Validation of SSR Markers Linked to the Bean Common Mosaic Virus (BCMV) Resistance in Cowpea (\u3cem\u3eVigna unguiculata\u3c/em\u3e L.) Genotypes

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    Cowpea, Vigna unguiculata (L.) is one of the important grain and fodder legume crops in the world, especially in tropics and subtropics. Which can adapted different climatic conditions such as high temperature and drought. It is not only important as a grain and fodder but also improve fertility of poor soils by fixing atmospheric nitrogen. An estimated cultivated area of cowpea is 12.5mha in worldwide (FAOSTAT, 2013). The grain and fodder productivity of cowpea are greatly affected by a number of biotic factors such as plant pathogens and insect pests. Among plant pathogens, viruses are considered to be a major constraint (Gioi et al., 2010). More than 40 viruses are reported from cowpea growing areas of the world. Among viruses, Bean common mosaic virus (BCMV) is very serious problem on cowpea in southern part of India especially cowpea growing areas of Karnataka. The BCMV is a member of potyvirus group and it can infect other legume crop family. Virus is seed borne and easily spread by aphids. Its chemical and cultural control neither economical nor ecofriendly. The host plant resistance has been proved the best strategy for its management. Hence it is necessary to identify stable resistance sources for BCMV disease in cowpea. Therefore large scale screening is needed to identify the durable resistance among diverse genotypes of cowpea. The basic requirements for any crop improvement programme are genetic variation for the trait of interest

    Advances the Forward Security in Parallel Network File System using An Efficient and Reliable Key Exchange Protocols

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    In parallel file system we can disperse data over numerous nodes to permit simultaneous access by various errands of a parallel application. By play out the numerous errands in a parallel system is commonly to reduce execution and solid access to substantial data sets. In this work, we research the issue of secure many to numerous correspondences in substantial scale network file systems that bolster parallel access to different storage devices. That is, we consider a correspondence model where there are countless getting to various remote and conveyed storage devices in parallel. Especially, we concentrate on the most proficient method to trade key materials and set up parallel secure sessions between the clients and the storage devices in the parallel Network File System the present Internet standard in a productive and versatile way. In this paper we are proposed convention for performing key trade and furthermore build up parallel secure session amongst clients and storage devices. In this paper we are likewise proposed another idea for encryption and decoding of put away data. By actualizing this procedure we are utilizing mixture encryption and decoding calculation. By actualizing those ideas we can enhance execution of network and furthermore give greater security of put away data in the put away devices

    Assessing Software Reliability Using Exponential Imperfect Debugging Model

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    Software reliability is one of the most important characteristics of software quality. As the usage of software reliability is growing rapidly, accessing the software reliability is a critical task in development of a software system. So, many Software Reliability Growth Models (SRGM) are used in order to decide upon the reliable or unreliable of the developed software very quickly. The well known software reliability growth model called as Exponential Imperfect Debugging model is a two parameter Non Homogeneous Poisson Process model which is widely used in software reliability growth modeling. In this paper, we propose to apply Statistical Process Control (SPC) to monitor software reliability process. A control mechanism is proposed based on the cumulative observations of failures which are grouped using mean value function of the Exponential Imperfect Debugging model. The Maximum Likelihood Estimation (MLE) approach is used to estimate the unknown parameters of the model. The process is illustrated by applying to real software failure data

    Biological relationship of Bean common mosaic virus (BCMV) infecting cowpea with leguminous plant species

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    Bean common mosaic virus (BCMV) associated with cowpea mechanically inoculated to different legumi-nous plants. Out of nineteen including cowpea Var.C-152, the virus was easily transferred to ten different legumi-nous hosts. All other hosts assessed for the presence of BCMV were found to be uninfected. The number of days taken for symptom expression and symptoms were varied within plant species. Pole bean expressed mosaic symp-tom after long incubation period (15-18 days) whereas, shorter incubation period was observed in common bean and rice bean (7- 10 days). BCMV produced chlorosis, mosaic, leaf distortion, puckering, vein banding, vein clearing and vein netting on cowpea(C-152). A typical virus symptom, mosaic was observed in green gram, common bean, lime bean, rice bean and yard long bean, whereas, leaf rolling and leaf distortion was observed in black gram, pole bean and snap bean. The virus-host relationship was confirmed by back inoculation test to C. amaranticolor. Further symptomatic plants were subjected for Reverse Transcriptase polymerase chain reaction (RT-PCR) for molecular confirmation using BCMV coat protein (CP) specific primer pair. A PCR fragment size of 439bp was amplified for the symptomatic plants. The results generated indicated the ability of a plant to support virus expression and host speci-ficity of BMCV within the leguminous plant species

    Halogenation for improvement of seed yield and quality in chilli (Capsicum annuum L.)

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    Freshly harvested seeds of chilli variety Anugraha were treated with halogens namely Calcium oxy chloride (CaOCl2) and Iodine crystal (I2) indirectly through a carrier Calcium carbonate (CaCO3). The treatments included Control (Untreated), CaOCl2 + CaCO3 (2g each/kg seed), CaOCl2 + CaCO3 (4g each/kg seed), Iodine crystal + CaCO3 (50mg each/kg seed) and Iodine crystal + CaCO3 (100mg each/kg seed).  Seed treatment with CaOCl2 + CaCO3 @2g each/kg seed registered significantly higher values for fruits per plant, fruit weight, seed yield per plant and hundred seed weight followed by CaOCl2 + CaCO3 @4g each/kg seed. The treatments, CaOCl2 + CaCO3 @2 g each/kg seed and Iodine crystal + CaCO3 @100mg each/kg seed performed superior in seed quality with higher seedling vigour and lower electrical conductivity of seed leachates over other treatments, while untreated control recorded least seedling vigour indices and highest electrical conductivity

    Rapid Quantification of Dynamic and Spall Strength of Metals Across Strain Rates

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    The response of metals and their microstructures under extreme dynamic conditions can be markedly different from that under quasistatic conditions. Traditionally, high strain rates and shock stresses are measured using cumbersome and expensive methods such as the Kolsky bar or large spall experiments. These methods are low throughput and do not facilitate high-fidelity microstructure-property linkages. In this work, we combine two powerful small-scale testing methods, custom nanoindentation, and laser-driven micro-flyer shock, to measure the dynamic and spall strength of metals. The nanoindentation system is configured to test samples from quasistatic to dynamic strain rate regimes (103^{-3} s1^{-1} to 10+4^{+4} s1^{-1}). The laser-driven micro-flyer shock system can test samples through impact loading between 10+5^{+5} s1^{-1} to 10+7^{+7} s1^{-1} strain rates, triggering spall failure. The model material used for testing is Magnesium alloys, which are lightweight, possess high-specific strengths and have historically been challenging to design and strengthen due to their mechanical anisotropy. Here, we modulate their microstructure by adding or removing precipitates to demonstrate interesting upticks in strain rate sensitivity and evolution of dynamic strength. At high shock loading rates, we unravel an interesting paradigm where the spall strength of these materials converges, but the failure mechanisms are markedly different. Peak aging, considered to be a standard method to strengthen metallic alloys, causes catastrophic failure, faring much worse than solutionized alloys. Our high throughput testing framework not only quantifies strength but also teases out unexplored failure mechanisms at extreme strain rates, providing valuable insights for the rapid design and improvement of metals for extreme environments
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