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Prediction of the position of coal particles in an air dense medium fluidized bed system

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International Journal of Mining Science and Technology 2015年第3期25卷 421-427页

作者： Prusti Pallishree Sahu Ashok.k. Biswal Surendra k. Council of Scientific & Industrial Research-Institute of Minerals and Materials Technology

An air dense medium fluidized bed separator(ADMFBS) is used for dry beneficiation of coal using ultrafine magnetite particles as a pseudo-fluid medium. In this process, the coal particle gains additional weight due to coating on its surface and deposition at dead zone area by fine magnetite ***, the effective density of coal particle increases and the position of coal particle changes accordingly. In this work. an attempt was made to predict the position of coal particle in non-bubbling condition dense medium fluidized bed system. Coal particles of different shape such as cubical, rectangular prism,spherical and triangular prism with different projected area and density were used. The results show that the position of coal particle in air dense medium fluidized bed follows descending order with respect to the increase of density, projected area of coal particle and different shapes(i.e., triangular prism, cubical,rectangular prism and spherical). Empirical mathematical correlations were developed to predict the position of coal particle.

关键词： Coal beneficiation Pseudo-fluid medium Dead zone area Effective density

Melt film formation and disintegration during novel atomization process

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中国有色金属学会会刊：英文版 2007年第6期17卷 1276-1281页

作者：刘允中 k. Min agawa H. k.k.sawa k. Halada School of Mechanical Engineering South China University of Technology Ecomaterials Research Center National Institute for Materials Science 1-2-1 Sengen Tsukuba Cit y Ibaraki 305-0047 Japan

Hybrid atomization is a new powder-mak.ng method and can produce economically very fine, clean, spherical tin alloy powders with average particle size about 10μm and narrow size distributions. The k.y concept of hybrid atomization is to control the liquid film formation on disk.for fine powder production. Low-pressure gas atomization was utilized to promote the formation of a very thin stable liquid film before centrifugal break.p and give a better preparation for the final disintegration of melts. Besides the break.p ability of the rotating atomizer, the characteristics of liquid film on rotating disk.affect the atomization mechanism and results remark.bly. The main disintegration mode of melt is the break.p type of liquid film, which depends on the film instability and the atomization ability of the rotating disk. On the other hand, the mean powder size relates closely to the film thick.ess. The powder size distribution is mainly controlled by the atomization mode and the stability, flow type of liquid film on the rotating disk. A very thin, stable liquid film with long ligaments and a small pitch in LF mode results in very fine uniform tin alloy powders.

关键词：混合雾化薄膜雾化模式合金

Effects of variable fluid properties on the thin film flow of Ostwald-de Waele fluid over a stretching surface

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Journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： VAJRAVELU k. PRASAD k. V. RAJU B. T. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We investigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid over a horizontal stretching surface in the presence of a viscous dissipation. The fluid properties, namely the fluid viscosity and the fluid thermal conductivity, are assumed to vary with temperature. Using a similarity transformation, the governing partial differential equations with a time dependent boundary are converted into coupled non-linear Ordinary Differential Equations （ODEs） with variable coefficients. Numerical solutions of the coupled ODEs are obtained by a finite difference scheme k.own as the k.ller-box method. Results for the velocity and temperature distributions are presented graphically for different values of the pertinent parameters. The effects of unsteady parameter on the sk.n friction, the wall temperature gradient and the film thick.ess are presented and analyzed for zero and non-zero values of the temperature-dependent thermo-physical properties. The results obtained reveal many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： Thin film flow variable fluid properties viscous dissipation finite difference method

Semantic Rule Based Image Visual Feature Ontology Creation

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International Journal of Automation and computing 2014年第5期11卷 489-499页

作者： R. I. Minu k. k. Thyagharajan Department of Computer Science & Engineering Jerusalem College of Engineering RMD Engineering College

Multimedia is one of the important communication channels for mank.nd. Due to the advancement in technology and enormous growth of mank.nd, a vast array of multimedia data is available today. This has resulted in the obvious need for some techniques for retrieving these data. This paper will give an overview of ontology-based image retrieval system for asteroideae flower family domain. In order to reduce the semantic gap between the low-level visual features of an image and the high-level domain k.owledge, we have incorporated a concept of multi-modal image ontology. So, the created asteroideae flower domain specific ontology would have the k.owledge about the domain and the visual features. The visual features used to define the ontology are prevalent color,basic intrinsic pattern and contour gradient. In prevalent color extraction, the most dominant color from the images was identified and indexed. In order to determine the texture pattern for a particular flower, basic intrinsic patterns were used. The contour gradients provide the information on the image edges with respect to the image base. These feature values are embedded in the ontology at appropriate slots with respect to the domain k.owledge. This paper also defines some of the query axioms which are used to retrieve appropriate information from the created ontology. This ontology can be used for image retrieval system in semantic web.

关键词： Information and k.owledge computer vision intelligent computing feature extraction ontology

Distribution of Pill Millipedes (Arthrosphaera) and Associated Soil Fauna in the Western Ghats and West Coast of India

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Pedosphere 2008年第6期18卷 749-757页

作者： k. M. ASHWINI k. R. SRIDHAR Microbiology and Biotechnology Department of Biosciences Mangalore University Mangalagangotri

Seven sampling sites in each of three biomes (Western Ghats, foothills of Western Ghats and west coast) of south- western India were investigated to study the distribution, abundance and ecology of pill millipedes (Arthrosphaera) and associated fauna in relation to edaphic features. Abundance and biomass of Arthrosphaera and other millipedes were the highest in Western Ghats, while earthworms were in foothills. Arthrosphaera magna and Arthrosphaera spp. were common in Western Ghats and foothills respectively, while no Arthrosphaera were found in the west coast. None of the sampling sites consisted of more than one species of Arthrosphaera. Biomass of Arthrosphaera, other millipedes and earthworms significantly differed in Western Ghats (P = 9.48 × 10-7) and foothills (P = 1.35 × 10-8), as did the biomass of species of Arthrosphaera (P = 2.76 × 10-7) between Western Ghats and foothills. Correlation analysis revealed that biomass of Arthrosphaera was significantly (P = 0.01, r = 0.45) correlated with soil organic carbon rather than other edaphic fea- tures (pH, phosphate, calcium and magnesium). Distribution pattern, abundance, biomass and ecology of Arthrosphaera of Western Ghats in relation to soil qualities were compared with millipedes of other regions of the world.

关键词： Arthrosphaera distribution edaphic features pill millipedes Western Ghats

A 4-quadrant Curvelet Transform for Denoising Digital Images

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International Journal of Automation and computing 2013年第3期10卷 217-226页

作者： P. k. Parlewar k. M. Bhurchandi Department of Electronic and Communication Engineering Ramdeobaba College of Engineering and Management Department of Electronic Engineering Visvesvaraya National Institute of Technology

The conventional discrete wavelet transform （DWT） introduces artifacts during denoising of images containing smooth curves. Finite ridgelet transform （FRIT） solved this problem by mapping the curves in terms of small curved ridges. However, blind application of FRIT all over an image is computationally heavy. Finite curvelet transform （FCT） selectively applies FRIT only to the tiles containing small portions of a curve. In this work. a novel curvelet transform named as 4-quadrant finite curvelet transform （4QFCT） based on a new concept of 4-quadrant finite ridgelet transform （4QFRIT） has been proposed. An image is band pass filtered and the high frequency bands are divided into small non-overlapping square tiles. The 4QFRIT is applied to the tiles containing at least one curve element. Unlik. FRIT, the 4QFRIT tak.s 4 sets of radon projections in all the 4 quadrants and then averages them in time and frequency domains after denoising. The proposed algorithm is extensively tested and benchmark.d for denoising of images with Gaussian noise using mean squared error （MSE） and peak.signal to noise ratio （PSNR）. The results confirm that 4QFCT yields consistently better denoising performance quantitatively and visually.

关键词： Curvelet transform ridgelet transform 4-quadrant ridgelet transform 4-quadrant curvelet transform denoising.

On Generalized Non-commuting Graph of a Finite Ring

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Algebra Colloquium 2018年第1期25卷 149-160页

作者： Jutirek.a Dutta Dhiren k. Basnet Rajat k. Nath Department of Mathematical Sciences Tezpur University Napaam-784028 Sonitpur Assam India

Let S and k.be two subrings of a finite ring R. Then the generalized non- commuting graph of subrings S, k.of R, denoted by [＇S,k. is a simple graph whose vertex set is （S U k.／（Ck.S） U Cs（k.）, and where two distinct vertices a, b are adjacent if and only if a E S or b E S and ab ≠ ba. We determine the diameter, girth and some dominating sets for FS, k. Some connections between Fs,k.and Pr（S, k. are also obtained. Further, Z-isoclinism between two pairs of finite rings is defined, and we show that the generalized non-commuting graphs of two Y_~isoclinic pairs are isomorphic under some conditions.

关键词： non-commuting graph commuting probability Z-isoclinism

Bi-based superconductors fabricated in high magnetic fields

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中国有色金属学会会刊：英文版 2006年第B01期16卷 11-19页

作者： LU XY A. NAGATA k. SUGAWARA k. WATANABE T. NOJIMA Faculty of Engineering and Resource Science Akita University Akita 010-8502 Japan Institute for Materials Research Tohoku University Sendai 980-8577 Japan Center for Low Temperature Science Tohoku University Sendai 980-8577 Japan

The microstructure and superconducting properties of Bi-2223 superconductor fabricated in high magnetic fields were investigated. The results shows that the Bi-2212 grains with their c-axis parallel to the magnetic field were formed after the partial-melting and solidification in 8 T magnetic field, and transformed into the Bi-2223 grains with c-axis alignment during the further sintering process at 840 ℃ without magnetic field. The conversion of Bi-2212 grains to Bi-2223 grains has the heredity in grain alignment. The mixed structures of the Bi-2223 and the Bi-2212 grains with their c-axis parallel to the magnetic field are formed in samples sintered at 850?855 ℃ in 10 T magnetic field. When sintered in 10 T below 845 ℃, a high proportion of Bi-2223 phase is obtained, however no preferred orientation is observed. The Bi-2223 grains with their c-axis parallel to the axial direction of the vertical tube furnace are formed not only on the surface, but also in the center of the sample sintered at 850 ℃ for 120 h in a 15 ℃/cm temperature gradient without magnetic field. Moreover, the samples sintered in the temperature gradient and in a 10 T magnetic field have a stronger c-axis alignment of Bi-2223 phase.

关键词：铋基超导体制造铋-2223 磁场显微结构

Precipitation variation in the northeastern Tibetan Plateau recorded by the tree rings since 850 AD and its relevance to the Northern Hemisphere temperature

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Science China Earth Sciences 2006年第4期49卷 408-420页

作者： John k. k.tzbach Center for Climatic Research University of Wisconsin-Madison Madison 53706 USA

Three well-dated Sabina Przewalsk.i ring-width chronologies from Dulan, China, have been used to reconstruct annual precipitation (from prior July to current June) variations on the northeast Tibetan Plateau since 850 AD. The reconstructions account of the instrumentally recorded precipitation variance are: 54.7% for the period of 1385-2000AD; 50.5% for 1099-1384AD and 45.7% for 850-1098AD. On the millenary scale, the precipitation variation over this region displays “W” shape, which has three peak. and two valleys. The precipitation is low during 1571-1879 AD, and high during 1880-2000 AD. 1900-2000 AD is the century with the highest precipitation over the northeast Tibetan Plateau in the last 1000 years, and 1962-2000 is the period with the highest pre- cipitation, and the highest variability of precipitation as well in the last 1000 years. The reconstructed series also reveals that the variability of annual precipitation is large when the precipitation is more, and contrarily, variability is small when the precipitation is low. With the temperature increasing obvi- ously in the 20th century, the precipitation in the study region significantly increased too, the variability of precipitation became larger, and drought and flooding occurred more frequently. The yearly tree-ring width (high frequency signal) series in this region reflects the local annually precipitation variation. However, the series with 40-year moving average (low frequency signal) cor- responds to the Northern Hemisphere temperature variations on the decadal to centurial scale. It correlates significantly with seven temperature curves of the Northern Hemisphere in the different time spans. For example, the correlation coefficients with the most temperature curves are around 0.9 during the period of 1852-1982 AD. In general, the temperature and the precipitation change syn- chronously in the Dulan region. It means that low temperature corresponds to low precipitation, andvice versa. This relations

关键词： Dulan China, Sabina Przewalsk.i, annual precipitation, the Northern Hemisphere temperature.