2,947 research outputs found

    Study of Staebler-Wronsky degradation effect in a Si:H based P-I-N solar cells

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    The objective of this study is to improve the stability and efficiency of thin solar cells with emphasis on a-Si:H devices. The research project was broken down into three main phases. The first involves designing and building a UHV glow discharge system; the second involves making good quality films and eventually efficient cells; the final phase will be analytical

    A Framework for Developing Real-Time OLAP algorithm using Multi-core processing and GPU: Heterogeneous Computing

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    The overwhelmingly increasing amount of stored data has spurred researchers seeking different methods in order to optimally take advantage of it which mostly have faced a response time problem as a result of this enormous size of data. Most of solutions have suggested materialization as a favourite solution. However, such a solution cannot attain Real- Time answers anyhow. In this paper we propose a framework illustrating the barriers and suggested solutions in the way of achieving Real-Time OLAP answers that are significantly used in decision support systems and data warehouses

    A New Concept of Transonic Galactic Outflows in a Cold Dark Matter Halo with a Central Super-Massive Black Hole

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    We study fundamental properties of isothermal, steady and spherically symmetric galactic outflow in the gravitational potential of a cold dark matter halo and a central super-massive black hole. We find that there are two transonic solutions having different properties: each solution is mainly produced by the dark matter halo and the super-massive black hole, respectively. Furthermore, we apply our model to the Sombrero galaxy. In this galaxy, Chandra X-ray observatory detected the diffuse hot gas as the trace of galactic outflows while the star-formation rate is low and the observed gas density distribution presumably indicates the hydrostatic equilibrium. To solve this discrepancy, we propose a solution that this galaxy has a transonic outflow, however, the transonic point forms in a very distant region from the galactic center (?\sim 127 kpc). In this slowly accelerated transonic outflow, the outflow velocity is less than the sound velocity for most of the galactic halo. Since the gas density distribution in this subsonic region is similar to the hydrostatic one, it is difficult to distinguish the wide subsonic region from hydrostatic state. Such galactic outflows are dfferent from the conventional supersonic outflows observed in star-forming galaxies.Comment: 7 pages, 3 figures, accepted for publication in JPS Conference Proceedings. arXiv admin note: substantial text overlap with arXiv:1405.345

    Transpiration cooling of a heat generating porous plate

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    This investigation is a continuation of a thesis by T. S. Purewal. Several of the simplifying assumptions made by the above author are either ignored or the justifiability of such assumptions is probed into in order to obtain a more rigorous solution. Effects of the assorted grain size, non-Newtonian cooling, direction of coolant flow, thickness of the porous heat generating plate, specific heat of the coolant, and compressibility of the coolant are investigated in this thesis. Variation of maximum temperature of both coolant and the solid material for different types of heat source distribution are also studied. As the grain size decreases heat transfer area per unit volume increases considerably. It is also observed that the temperature difference between the solid and the coolant increases as the particle size increases. It is established that the assumption of Newtonian cooling does not introduce any error in the case of a porous plate formed by very small spheres. Expressions are also derived for maximum coolant and solid temperatures under uniform, linear, exponential and sinusoidal heat source distribution. The effect of thickness of the plate on heat distribution and on the temperature of the solid and the coolant have been mathematically expressed. The specific heat of coolant fluid does affect the temperature of the coolant. Specific heats of different fluids are not equal. Even for the same fluid specific heat generally varies with temperature. How these variations affect the coolant temperature was studied and equations for different categories of heat source distribution developed. Graphs based on such equations are presented. In the case of compressible fluids higher pressures are found to be advantageous. Advantages include lower percentage pressure drop, lower figure of merit and higher mass rate of flow for same linear velocity --Abstract, pages 2-3

    Design and implementation of an oil leakage monitoring system based on wireless network

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    Monitoring pipeline leaks is one of the recent hot studies. Leakage may occur because of time corrosion in the tube raw materials. To reduce the negative consequences of this leak, an effective leak detection system is used to prevent serious leakage accidents and damage in oil pipelines. Buildings, ecosystems, air pollution, and human life are all at risk in case of leakage occurs which could lead to fires. This paper introduces one of the research methods for the detection of pipeline leaks with a particular focus on software-based methods. The computer board interface (CBI) and wireless sensor networks have been used beside Arduino as a micro-monitor for the entire system. ZigBee is also utilized to send read data from sensors to the monitoring system displayed on the LabVIEW graphical user interface (GUI). The operator can take direct action when a leak occurs. The effectiveness of the leakage monitoring process and its practical use are demonstrated by the introduction of computerized techniques based on pressure gauge analysis on a specific pipeline in the laboratory. The result showed that the system is widely covered, accurate data transmission and robust real-time performance which reduces economic losses and environmental pollution

    Harnessing Digital Transformation: A Pathway to Achieving the 2030 UNSDGs and Ensuring Sustainable Corporate Performance

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    This chapter explores the essential intersection of digital transformation and sustainability within the context of contemporary business enterprises. It is based on the urgent need for the United Nations' Sustainable Development Goals (UNSDGs) 2030, and it underscores the transformative potential of digital technologies such as Artificial Intelligence, the Internet of Things, and blockchain in reshaping sustainable business practices. This focuses on the switch from traditional, profit-driven models to models that prioritize people, profits, and the planet. The critical conclusion is the emancipation of stakeholders who have evolved from being passive receivers of CSR activities to become active collaborators in sustainability initiatives enabled by digital advances. In addition to that, the barriers that naturally occur because of the digital divide and ethical hurdles must be collectively resolved. Ultimately, it reverts back to the narrow, yet arduous path that leads to the shared value; cooperation and innovation as a way forward to a sustainable digital future

    Study of Literature by Students of Engineering Courses

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    The paper titled “Study of Literature by Students of Engineering” begins with an introduction on the importance of literature for communicative purposes and moves, highlighting the demands the global market has for engineers possessed with communicative competence in English. Mere terminology is not going to help engineers express themselves during all occasions. Literature, the mirror of life is not meant only for the students of science and humanities but also for those of engineering courses in order to have rosy future both in the world of technology with the knowledge of technology, and the world of Reality with the knowledge of literature.  Besides pinpointing the vacuum that can be appropriately filled with the study of literature, the paper justifies the incorporation of literature in the curriculum and the importance of study of literature for students of engineering courses. The paper advocates certain techniques that could be implemented in order to enhance the communicative competence of students in English through literature. It highlights the advantages of inclusion of literature in the text material in English for engineering students. The paper ends with the point that literature creates an ambience for engineering students to enlighten themselves with innumerable expressions that make a whale of difference in their communication. Keywords: literature, communicative competence, creativity, innovation, English syllabu

    Success of Aquaculture Industry with New Insights of Using Insects as Feed: A Review

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    Most of world's fish and seafood are produced by aquaculture, which is one of the biggest contributors to the world's food security. The substantial increase in prices of conventional feed ingredients and the over-exploitation of natural resources are some of the biggest constraints to aquaculture production. To overcome this stress, different approaches and techniques are used, among which the use of non-conventional feed ingredients in the aquaculture sector is the most recent approach. Different non-conventional feed ingredients such as plant-based products, algae (both micro and macroalgae), single-cell protein (bacteria and yeast), and insect meal are currently used in aquaculture for sustainable food production. Amongst all these novel ingredients, insects have greater potential to replace fishmeal. The existence of about 1.3 billion tons of food and agriculture waste from the food chain supply poses a serious environmental threat. Insects are tiny creatures that can thrive on organic waste and thus can convert the waste to wealth by the bioconversion and nutritional upcycling of organic waste. Insects have the potential to recover nutrients from waste aquaculture products, and many fish species feed on insects naturally. Therefore, employing insects in the aquaculture sector to replace fishmeal is an eco-friendly approach. The present review briefly highlights emerging non-conventional feed ingredients, with special attention given to insects. The current review also focuses on the nutritional value of insects, factors affecting the nutritional value of insects, potential insects that can be employed in the aquaculture sector, the physiological response of fish when fed with insect meal, techno-functional properties of insect meal, and emerging approaches for addressing possible downsides of employing insect meal in fish diets. Finally, it suggests avenues for further research into these inventive fishmeal replacements

    Synthesis and Structural Characterization of Cr2O3 Nanoparticles Prepared by Using Cr(NO3)3.9H2O and Triethanolamine Under Microwave Irradiation

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    In this study, Chromium oxide nanoparticles (Cr2O3-NPs) was prepared by sol-gel method, using Cr(NO3)3.9H2O as a Precursor material, triethanolamine (TEA) as a template and water as green solvent under microwave irradiation . X- ray diffraction (XRD), Scanning electron microscopy (SEM), Rietveld refinement and Fourier Transform Infrared spectroscopy (FTIR) were employed to characterize the average  crystallite size, crystalline structure, morphology, unit cell parameters and chemical groups of the annealed powder. From  XRD data and Dicvol 91 software analysis, the crystal system was found to be rhombohedral structure for samples. The average  crystallite size is calculated by using Debye-Scherrer formula, crystallites size and strain are calculated by using Williamson-Hall formula. The effect of particle size on the crystal lattice distortion ratio, specific surface area, dislocation density and number of unit cell was discussed. A good agreement is between XRD data and FIR data. The qualitative phase analysis is performed by Rietveld analysis using “Fullprof” program of Cr2O3-NPs. Keywords: Cr2O3, Nanoparticles,  Sol – Gel , Structural Properties, Rietveld refinement
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