1,256 research outputs found

    Effect of Cooling Conditions, Retrofitting on Strength of Concrete Subjected to Elevated Temperature

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    Concrete has a high degree of fire resistance at moderate temperatures. High temperatures, however, cause concrete to lose its stiffness and strength. The effects of cooling techniques and retrofitting on the strength of concrete exposed to high temperatures have not been synchronized in previous studies. This experimental research aims to evaluate the effect of cooling conditions and the effectiveness of retrofitting concrete subjected to elevated temperatures. Four types of concrete: M 20 normal concrete (NC); M 20 metakaolin concrete (MC); M 40 standard concrete (SC); and M 40 self-compacting concrete (SCC) are considered in this study. A total of 864 samples consisting of cube, beam, and cylinder specimens are subjected to sustained elevated temperatures of 400oC, 600oC, and 800oC for 2 hours rating. The weight and strength of half of the heat-damaged samples are assessed following natural air cooling (NAC) and water jet cooling (WJC). The remaining 50% of samples retrofitted with carbon fiber reinforced polymer (CFRP) are tested to evaluate the upgraded strength. The experimental findings demonstrate that water jet cooling (WJC) causes more strength degradation, and CFRP proves to be effective in restoring the strength of heat-deteriorated specimens. Overall, self-compacting concrete (SCC) has shown high resistance to elevated temperatures. Doi: 10.28991/CEJ-2023-09-07-013 Full Text: PD

    Secure Data Control: Privacy and Security based on ABE for Access Control over Cloud

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    In today's world, there is a strong requirement for sharing information over cloud. However, privacy and security remains a setback especially when working with bulk amounts of data in the Cloud. Data is abundantly stored outside the control of the data owner’s machine with lack of his knowledge to the data owner, how the data being used and where the data are being stored. So, there is a necessity for the data owner to have a more control over their data, similar to the level of control they possess when the data are being stored on their own machine. For example, when a data owner shares an important file with his colleague, he cannot trust what his colleague will do with his data. In this paper, we try to address this problem by monitoring and preventing unauthorized operations by the data consumer. We present a solution called Secure-Data, which bundles the data owner’s data and specified policy, based on XACML, in an object called Secure-Data object. Secure-Data enforces the policies set out by the data owner by communicating with the cloud based applications to disable certain operations and/or run a background process for monitoring the data. We define a software based protocol that will enable to secure the data in the cloud and will support the use of the android app for authentication purposes

    Analysis of lead and arsenic in cosmetics and assessment of students awareness about cosmetic toxicity

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    Background: Many people believe that all cosmetics are safe but there are number of studies proving that majority of the cosmetics contains heavy metals or other chemicals. In this study we selected two heavy metals arsenic and lead because as per the Indian scenario is concerned most of the Hindu and Muslim females uses lead/arsenic based cosmetics.Methods: For the qualitative/quantitative estimation to detect heavy metals such as arsenic and lead in cosmetics, 20 different types of cosmetics were purchased from local market, labelled and analysed by qualitative test for heavy metals method and ICP-AES Analysis of cosmetics method.Results: A questionnaire was framed out in English and analysis showed that students had an adverse effect while using cosmetic products. Preliminary analysis of some samples gave positive results and for confirmation these samples were sent to IIT Bombay for ICP-AES analysis. Some of the samples showed variable level of heavy metals such as lead and arsenic. Highest concentration of lead and arsenic was found in Surma followed by Sindoor, lip balm and Kajal.Conclusions: Heavy metals are one of the major contaminant in our eco system. Apart from this a number of cosmetic products also contain the same. Chronic use of this kind of cosmetic products will leads heavy metal toxicity

    Study of serum sodium and potassium concentration in cataract patients

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    Background: The present study was aimed to study alterations in levels of sodium and potassium in age-related cataract patients.Methods: 50 senile cataract patients in age group of 50 to 80 years and 50 control group were included for the study. Serum sodium and potassium levels were determined by flame photometry.Results: Significant (<0.0001)  increased levels of plasma Na+ in cataract patients (145.06 ± 5.84mEq/lit) were found as compared with controls (141.18 ± 2.67mEq/lit). While Plasma K+ the conc. in cataract patients (4.18 ± 0.34mEq/lit) was not significantly (P = 0.002) increased when compared with controls (4.13 ± 0.32mEq/lit).Conclusion: Na, K-ATPase is responsible for maintaining the correct concentrations of sodium and potassium in lens cells. In ageing, lens fibers undergoes oxidation, and glycation may decrease Na, K-ATPase activity. The asymmetrical distribution of Na, K-ATPase activity in the epithelium and fibers may contribute to ionic currents that flow in and around the lens. So, abnormal elevation of lens sodium can be used as a marker in the opacification of the lens cortex in age-related human cataract

    Molecular theory of elastic constants of liquid crystals. III. Application to smectic phases with tilted orientational order

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    Using the density functional formalism we derive expression for the distortion free energy for systems with continuous broken symmetry and use it to derive expression for the elastic constants of smectic phases in which director is tilted with respect to the smectic layer normal. As in the previous papers of the series (Phys. Rev. A {\bf 45}, 974 (1992), E {\bf 49}, 501, (1994)) the expressions for the elastic constants are written in terms of order and structural parameters. The structural parameters involve the generalised spherical harmonic coefficients of the direct pair correlation function of an effective isotropic liquid. The density of this effective isotropic liquid depends on the nature and amount of ordering present in the system and is evaluated self- consistently. We estimate the value of elastic constants using reasonable guess for the order and structural- parameters.Comment: 31 pages; 1 Fig. in GIF format, To be appear in Phys. Rev.

    Effects and consequences of small-scale cage culture technology adoption in Kerala

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    Small-scale fish farming is critical in ensuring food security and employment in many developing countries. Small-scale cage culture for Etroplus suratensis was introduced in the state by the Department of Fisheries, Government of Kerala with the same objectives. The demand for the species has shown considerable increase in the recent years and f m gate prices are as high as Rs 450kg in the peak season. Elevation to the status of State Fish has also helped the culture of the species in attracting the attention of policy makers leading to promotion of its culture. Cage culture in brackishwater bodies, a relatively new technology to the State, was popularized among the tsunami affected fishermen along with extension and technical support. The implementation of cage culture was promoted through the Brackishwater Fish Farmers' Development Agency (BFFDAs) and Agency for Development ofAquaculture Kerala (ADAK), two subsidiaries of the Department of Fisheries, Government of Kerala. The present study probes the effects and consequences of cage culture technology adoption among farmers based on primary data collected from sample respondents during the initial year of culture

    Three years follow up of open medial sub-talar dislocation of ankle: a case report

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    Open medial sub-talar dislocation is a rare lesion in traumatology. Even after early treatment, these injuries progress to sub-talar arthrosis. Here we describe a case of 24 years male with open type 3B medial sub-talar dislocation with calcaneum sustentaculum tali fracture following road traffic accident. He underwent emergency wound debridement and internal fixation with K-wires and VAC application. He was on regular monthly follow-up for 6 months and then 6 monthly follow-ups till date. K-wires were removed 8 weeks after surgery and gradual range of movement was started. Partial weight bearing was started at 12 weeks. He was pain free and returned to work after 8 months. At 3 years follow up patient is able to walk without pain, normal painless ROM at ankle. To the best of our knowledge, long term follow-up of patient with these lesions is not reported. Here we present a case with 3 years follow-up showing good results in patient with open sub-talar dislocation after early management with internal fixation with K-wires and VAC dressing

    A comparative study of heating elements used for the development of textile heaters

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    The focus of this paper is to make a comparison between five different types of conductive, heatable samples. These textile samples have been produced according to the five most important implementation techniques such as knitting, weaving, embroidery, printing and nonwoven padding. The idea is to identify a conductive option best suitable for a heating application. This study was divided into four major steps: choosing the adequate materials, swatch production, conductivity measurements and heating behaviour assessment. The first three methods use electro conductive wires as heating elements, the fourth uses conductive ink and the fifth uses carbon black coating. For all of them, resistance, current and heat distribution was measured. The results show that the best options for the development of a wearable textile heating system are the embroidered and the woven techniques, as their mechanical strength and elasticity, is sufficiently high and the fabric/substrate structure allows the insertion/deposition of different types of heating element

    Harnessing ornamental fisheries resources for sustainable growth and development: A trade perspective from Kerala, India

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    Ornamental fish trade has gained paramount importance with more than 125 countries involved in the freshwater and marine fishes. The global trade is estimated to be around US $ 450 million registering a growth rate of ten percent since 2001. Asia caters up to 60 per cent of the global trade while India stands with a dismal 0.9 per cent with a portfolio of 30-35 fresh water species. The ornamental fish resources of Kerala has huge potential with untapped and unexploited resources. However the performance of the sector is not worthy and production is much below the demand. The SWOL analysis - Strengths, Weaknesses, Opportunities and Limitations analysis - is done to analyse the status of ornamental fish industry in Kerala. The results indicated that good export market, high demand, availability of under-utilized marine resources, potential for rural development, low cost effort, efficiency of ornamental fish marketers, institutional support for development and promotions were the major strengths. Dependence on wild caught species, inadequate data on resources, wastage of resources, unwillingness towards marine fishes, lack of trained/ skilled manpower and organized trade, lack of adept technologies, poor marketing facilities, backwardness in international market, weak market image and lack of fishing regulations were the major inherent weaknesses. The major opportunities were enhancement of species portfolio, increasing market value, less capital intensive, high popularity and demand, breeding and culture of indigenous fishes, faster market growth, entry to new market destinations, increased awareness of international buyers and support of government. Technological backwardness, technology transfer, insufficient awareness programmes, adverse government policies, competitions from neighboring countries, sustainability of resources and drastic drop in fish prices were the major limitations. The study suggests concerted efforts by the different stakeholders to enhance the production of the sector
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