1,434 research outputs found

    Experimental and numerical study on axial impact loading of pultruded composite tubes

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    The application of fibre reinforced composites has been increasing in the area of impact and blast loading of structures. The major advantages of these materials over metals are higher specific energy absorption, more economical, low weight and less maintenance. In this work, an attempt is made to study the energy absorption characteristics of unidirectional pultruded composite tubes. Two different cross sections (circular and square) were used for the study. To absorb more energy during the impact or blast loading the composite tubes have to deform progressively. To induce the progressive deformation of composite tubes two different types of triggering mechanisms were used. The energy absorption of each tube was studied experimentally. A new approach was adopted using cohesive elements for the numerical assessment of the energy absorbing capability of composite tubes. Finally the experimental and numerical results were compared

    Pultruded composite tubes for crashworthiness

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    Blast energy absorption of metal cans

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    Energy absorption of crushable tubes for protective structures under static, impact and blast loading

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    Wild Neurospora isolated from soil

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    Wild Neurospora isolated from soi

    Predicting the strength of seashell concrete using Adaptive Neuro-Fuzzy Inference System: An experimental study

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    La concha marina es una capa exterior dura y protectora creada por un animal que vive en el mar. A menudo se encuentran conchas marinas vacías y lavadas por las olas sobre las playas. Este producto marino puede ser utilizado como reemplazo parcial del agregado grueso en el concreto o del cemento en el concreto. Este artículo describe el uso de polvo de conchas marinas y agregados en el concreto para reemplazar el cemento y los agregados gruesos. El efecto de los residuos de conchas marinas en el concreto fue estudiado en términos de su resistencia a la compresión, resistencia a la tracción y resistencia a la flexión después de 28. 56 y 90 días de curado. El reemplazo de cemento por polvo de conchas marinas fue de 10%, 20% y 30% y el reemplazo de agregado grueso por agregado de concha marina fue 5%, 10% y 15%. Las propiedades del concreto de concha marina fueron comparadas con una muestra de mezcla control de grado M25 de concreto. También se ha intentado predecir la resistencia del concreto de concha marina utilizando un Sistema de Inferencia Adaptativo Neuro-Fuzzy (ANFIS). La predicción de la fuerza con este sistema estuvo de acuerdo con la fuerza experimental con un error mínimo de menos del 5%. Este estudio concluye que el reemplazo parcial de cemento y de agregado grueso por residuos de concha marina aumenta significativamente las propiedades mecánicas del concreto y permite la utilización adecuada de estos desechos de conchas marinas como material sostenible para el concreto.Seashell is a hard, protective outer layer created by an animal that lives in the sea. Empty seashells are often found washed up on beaches by beachcombers. This marine by-product can be used to partial replacement of coarse aggregate or cement in concrete. This paper describes the use of seashell powder and aggregate in the concrete for the replacement of cement and coarse aggregate. The effect of seashell waste in the concrete was studied in terms of its compressive strength, tensile strength and flexural strength after 28, 56 and 90 days of curing. The replacement of cement by seashell powder were 10%, 20% and 30% and replacement of coarse aggregate by seashell aggregate are 5%, 10% and 15%. The properties of seashell concrete were compared with control mix specimen of M25 grade of concrete. Also, it has been tried to predict the strength of the seashell concrete utilizing adaptive neuro-fuzzy inference system (ANFIS). The prediction of strength with the tool was agreeable with the experimental strength with the minimal error of less than 5%. This study concludes, that partial replacement of cement and coarse aggregate by seashell waste enhances the mechanical properties of the concrete significantly and enable proper utilization of these seashell waste as sustainable material for the concrete

    Women Entrepreneurship among the Context of Gender Aggressiveness, Opportunities and Hurdles of Informal Sector

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    Over the past decade, gender equality and women‘s empowerment have been explicitly recognized as key note only to the health of nations, but also to social and economic development.  Entrepreneurship amongst women has been a recent concern. Women have become aware of their rights and their work circumstances. However, women of the middle class are not too keen to alter their role in fear of social constraints the progress is more visible among upper class in urban cities. Our increasing dependency on service area has created numerous entrepreneurial opportunities especially for women where they can excel their skills with maintaining equilibrium in their life. This paper is an effort to know the Gender Competitiveness, Opportunities and Hurdles to women. Keywords: Agglomeration, Empowerment, Informal Sector, Women Entrepreneur

    Computational study of Staggered and Double Cross Flow Heat Exchanger

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    The preliminary findings of a comparative study of heat transfer rate and pressure drop between conventional staggered flow and double cross flow heat exchanger is reported. Excepting for the tube arrangements, the shell and tube dimensions, materials and inlet conditions are retained the same for the two configurations. While in the conventional arrangement, adjacent rows of tubes are normal only to the fluid flow in the shell, in the double cross-flow arrangement, they are normal to both fluid flow direction in the shell as well as to each other. Shell dimensions are 100 cm × 20 cm × 20 cm and tube outside and inside diameters are 1 cm and 0.8 cm. The shell and tube materials are steel and copper. Water and air were considered as tube and shell side fluids respectively, with an overall arrangement of parallel flow. The tube flow Reynolds number was fixed at 2200 and the shell flow Reynolds number was varied from 20 to 120 in the laminar regime and 360 to 600 in the turbulent zone. The study reveals that the proposed configuration gives a maximum increase of about 27 per cent in the heat transfer rate per unit pressure drop over the conventional one

    Molecular Cloning and Expression of a Phytase Gene from the Thermophilic Fungus, Thermomyces lanuginosus - RMB

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    Phytases are enzymes which hydrolyse phytate to produce inorganic phosphate and myo-inositol and thus they are promising candidates for food and feed industries. Thermomyces lanuginosus is known to produce a thermostable phytase. In this work, the Thermomyces lanuginosus strain RMB was chosen for cloning and expression of the phytase gene. Intronless primers were designed for phytase gene amplification and expression in E. coli, using the phytase gene sequence of T. lanuginosus (ATCC 200065). A product of ~1400 bp characteristic of phytase gene was obtained on PCR amplification of the fungal genomic DNA. This gene was cloned into pGEM-T easy vector and the positive clones were confirmed by restriction digestion and sequenced. The cloned gene obtained in this study will have a potential for producing the thermostable enzyme in large amounts, which could find applications in the feed industry to enhance the quality for poultry and piggery by supplementing it in their diets
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