1,240 research outputs found

    Digital Lessons for Enhancing Communicative Skills: A Handbook for Turkish EFL Teachers

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    It is necessary for English teachers who are interested in exposing their students to the authentic and communicative use of English to have access to model instructional materials. This project sought to develop a handbook and an accompanying website for teachers of English working with intermediate ESL/EFL students at university level. The handbook includes two theme-based lessons that emphasize the development of communicative competence with the help of engaging free digital tools. The content of the handbook can be improvised or modified and adapted to meet the needs of unique teaching-learning situations in case of need

    A fully CNN based fingerprint recognition system

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    In this paper, a fully cellular neural networks (CNN) based fingerprint recognition system is introduced. The system includes a preprocessing phase where the input fingerprint image is enhanced and a recognition phase where the enhanced fingerprint image is matched with the fingerprints in the database. Both preprocessing and recognition phases are realized by means of CNN approaches. A novel application of skeletonization method is used to perform ridgeline thinning which improves the quality of the extracted lines for further processing, and hence increases the overall system performance

    Energy intensity and environmental impact metrics of the back-end separation of ethylene plant by thermodynamic analysis

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    This study presents metrics of energy intensity and environmental impact of the back-end separation of ethylene plant consisting three interacting distillation columns by thermodynamic analysis. The objective is to explore the scope of reducing the energy for utilities and CO2 emissions. Thermodynamic analysis is carried out using the column targeting tool (CTT) to address the sustainability metrics of ‘Energy Intensity.’ CTT is based on the ‘Practical Near-Minimum Thermodynamic Condition’ representing a close to practical reversible column operation. Environmental impact metrics are estimated from the carbon tracking options. The carbon tracking are estimated by the CO2 emission data source of US-EPA-Rule-E9-5711 using natural gas as the primary fuel. The results show that the total reductions in energy loss and the total hot and cold utility are around 44 and 10 %, respectively; the total reductions in carbon dioxide are around 14 %. These improvements lead to considerable reductions in the operating costs. Thermodynamic analysis helps estimating and improving the energy and environmental sustainability metrics and hence can lead to a more sustainable separation by distillation columns. Keywords Ethylene plan

    Energy intensity and environmental impact metrics of the back-end separation of ethylene plant by thermodynamic analysis

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    This study presents metrics of energy intensity and environmental impact of the back-end separation of ethylene plant consisting three interacting distillation columns by thermodynamic analysis. The objective is to explore the scope of reducing the energy for utilities and CO2 emissions. Thermodynamic analysis is carried out using the column targeting tool (CTT) to address the sustainability metrics of ‘Energy Intensity.’ CTT is based on the ‘Practical Near-Minimum Thermodynamic Condition’ representing a close to practical reversible column operation. Environmental impact metrics are estimated from the carbon tracking options. The carbon tracking are estimated by the CO2 emission data source of US-EPA-Rule-E9-5711 using natural gas as the primary fuel. The results show that the total reductions in energy loss and the total hot and cold utility are around 44 and 10 %, respectively; the total reductions in carbon dioxide are around 14 %. These improvements lead to considerable reductions in the operating costs. Thermodynamic analysis helps estimating and improving the energy and environmental sustainability metrics and hence can lead to a more sustainable separation by distillation columns. Keywords Ethylene plan

    Seasonality of low flows and dominant processes in the Rhine River

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    Low flow forecasting is crucial for sustainable cooling water supply and planning of river navigation in the Rhine River. The first step in reliable low flow forecasting is to understand the characteristics of low flow. In this study, several methods are applied to understand the low flow characteristics of Rhine River basin. In 108 catchments of the Rhine River, winter and summer low flow regions are determined with the seasonality ratio (SR) index. To understand whether different numbers of processes are acting in generating different low flow regimes in seven major sub-basins (namely, East Alpine, West Alpine, Middle Rhine, Neckar, Main, Mosel and Lower Rhine) aggregated from the 108 catchments, the dominant variable concept is adopted from chaos theory. The number of dominant processes within the seven major sub-basins is determined with the correlation dimension analysis. Results of the correlation dimension analysis show that the minimum and maximum required number of variables to represent the low flow dynamics of the seven major sub-basins, except the Middle Rhine and Mosel, is 4 and 9, respectively. For the Mosel and Middle Rhine, the required minimum number of variables is 2 and 6, and the maximum number of variables is 5 and 13, respectively. These results show that the low flow processes of the major sub-basins of the Rhine could be considered as non-stochastic or chaotic processes. To confirm this conclusion, the rescaled range analysis is applied to verify persistency (i.e. non-randomness) in the processes. The estimated rescaled range statistics (i.e. Hurst exponents) are all above 0.5, indicating that persistent long-term memory characteristics exist in the runoff processes. Finally, the mean values of SR indices are compared with the nonlinear analyses results to find significant relationships. The results show that the minimum and maximum numbers of required variables (i.e. processes) to model the dynamic characteristics for five out of the seven major sub-basins are the same, but the observed low flow regimes are different (winter low flow regime and summer low flow regime). These results support the conclusion that a few interrelated nonlinear variables could yield completely different behaviour (i.e. dominant low flow regime)

    MOCVD growth and optical properties of non-polar (11-20) a-plane GaN on (10-12) r-plane sapphire substrate

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    Cataloged from PDF version of article.Non-polar a-plane GaN film with crystalline quality and anisotropy improvement is grown by use of high temperature AlN/AlGaN buffer, which is directly deposited on r-plane sapphire by pulse flows. Compared to the a-plane GaN grown on AIN buffer, X-ray rocking curve analysis reveals a remarkable reduction in the full width at half maximum, both on-axis and off-axis. Atomic force microscopy image exhibits a fully coalesced pit-free surface morphology with low root-mean-square roughness (similar to 1.5 nm). Photoluminescence is carried out on the a-plane GaN grown on r-plane sapphire. It is found that, at low temperature, the dominant emission at similar to 3.42 eV is composed of two separate peaks with different characteristics, which provide explanations for the controversial attributions of this peak in previous studies. (C) 2010 Elsevier B.V. All rights reserved

    Chemical storage of wind energy by renewable methanol production: Feasibility analysis using a multi-criteria decision matrix

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    This study is for the technoeconomic analysis of an integral facility consisting of wind energy-based electrolytic hydrogen production, bioethanol-based carbon dioxide capture and compression, and direct methanol synthesis. ASPEN Plus was used to simulate the facility producing 97.01 mt (metric tons) methanol/day using 138.37 mt CO2/day and 18.56 mt H2/day. A discounted cash flow diagram for the integral facility is used for the economic analysis at various hydrogen production costs and methanol selling prices. The feasibility analysis is based on a multi-criteria decision matrix consisting of economic and sustainability indicators comparing renewable and non-renewable methanol productions. The overall energy efficiency for the renewable methanol is around 58%. Fixation of carbon reduces the CO2 equivalent emission by around –1.05 CO2e/kg methanol. The electrolytic hydrogen production cost is the largest contributor to the economics of the integral facility. The feasibility analysis based on multi-criteria shows that renewable methanol production may be feasible

    Wavelet transform based new interpolation technique for satellite image resolution enhancement

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    In this research paper, we propose a new interpolation technique based on the Stationary Wavelet Transform (SWT) and iterative back projection (IBP) for satellite images. Firstly the low resolution image is interpolated by using bicubic interpolation and then decomposed into different subband images by SWT. Each subband is decimated to four lower low resolution images. The four low resolution images are interpolated and registered by using bicubic interpolation and IBP respectively. Inverse SWT (ISWT) is used to generate a Super-resolved output image. The proposed interpolation technique has been tested on several remote sensing images. The quantitative PSNR and SSIM results as well as the visual results show the superiority of the proposed interpolation technique over the other interpolation and image resolution enhancement techniques. For one of the images the PSNR of the proposed method has achieved 3.84dB, 2.11dB, and 1.1dB more improvements than bicubic interpolation, Irani and Peleg technique, and Wavlet Zero Padding technique respectively

    The role of the nature of the noise in the thermal conductance of mechanical systems

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    Focussing on a paradigmatic small system consisting of two coupled damped oscillators, we survey the role of the L\'evy-It\^o nature of the noise in the thermal conductance. For white noises, we prove that the L\'evy-It\^o composition (Lebesgue measure) of the noise is irrelevant for the thermal conductance of a non-equilibrium linearly coupled chain, which signals the independence between mechanical and thermodynamical properties. On the other hand, for the non-linearly coupled case, the two types of properties mix and the explicit definition of the noise plays a central role.Comment: 9 pages, 2 figures. To be published in Physical Review

    Metalorganic chemical vapor deposition growth and thermal stability of the AllNN/GaN high electron mobility transistor structure

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    Cataloged from PDF version of article.The AlxIn1-xN barrier high electron mobility transistor (HEMT) structure has been optimized with varied barrier composition and thickness grown by metalorganic chemical vapor deposition. After optimization, a transistor structure comprising a 7 nm thick nearly lattice-matched Al0.83In0.17 N barrier exhibits a sheet electron density of 2.0 x 10(13) cm(-2) with a high electron mobility of 1540 cm(2) V-1 s(-1). AnAl(0.83)In(0.17)N barrier HEMT device with 1 mu m gate length provides a current density of 1.0 A mm(-1) at V-GS = 0 V and an extrinsic transconductance of 242 mS mm(-1), which are remarkably improved compared to that of a conventional Al0.3Ga0.7N barrier HEMT. To investigate the thermal stability of the HEMT epi-structures, post-growth annealing experiments up to 800 degrees C have been applied to Al0.83In0.17N and Al0.3Ga0.7N barrier heterostructures. As expected, the electrical properties of an Al0.83In0.17N barrier HEMT structure showed less stability than that of an Al0.3Ga0.7N barrier HEMT to the thermal annealing. The structural properties of Al0.83In0.17N/GaN also showed more evidence for decomposition than that of the Al0.3Ga0.7N/GaN structure after 800 degrees C post-annealing
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