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An investigation into flow mode transition and pressure fluctuations for fluidized dense-phase pneumatic conveying of fine powders

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particuology 2014年第5期12卷 187-195页

作者： A.Mittal s.s.Mallick p.W.Wypych Department of Mechanical Engineering Thapar UniversityPatialaPunjab 147004India Faculty of Engineering and Information sciences University of WollongongWollongongNSW 2500Australia

This paper presents the results of an ongoing investigation into the fluctuations of pressure signals due to solids-gas flows for dense-phase pneumatic conveying of fine powders. pressure signals were obtained from pressure transducers installed along different locations of a pipeline for the fluidized dense-phase pneumatic conveying of fly ash （median particle diameter 30μm; particle density 2300 kg/m^3; loose- poured bulk density 700 kg/m^3） and white powder （median particle diameter 55 p.m; particle density 1600 kg/m^3 ; loose-poured bulk density 620 kg/m^3） from dilute to fluidized dense-phase. standard deviation and shannon entropy were employed to investigate the pressure signal fluctuations. It was found that there is an increase in the values of shannon entropy and standard deviation for both of the prod- ucts along the flow direction through the straight pipe sections. However, both the shannon entropy and standard deviation values tend to decrease after the flow through bend（s）, This result could be attributed to the deceleration of particles while flowing through the bends, resulting in dampened particle fluctua- tion and turbulence. Lower values of shannon entropy in the early parts of the pipeline could be due to the non-suspension nature of flow （dense-phase）, i.e., there is a higher probability that the particles are concentrated toward the bottom of pipe, compared with dilute-phase or suspension flow （high velocity）, where the particles could be expected to be distributed homogenously throughout the pipe bore （as the flow is in suspension）. Changes in straight-pipe pneumatic conveying characteristics along the flow direction also indicate a change in the flow regime along the flow.

关键词： Fluidized dense-phase pneumatic conveying Fine powders shannon entropy Flow transition particle turbulence

Interfacial Reactions and Cubic Neodymium Oxide Formation in Low Dispersed Nd203-siO2 system by Wet Chemical Method

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Chinese physics Letters 2009年第1期26卷 202-204页

作者： s. Duhan p. Aghamkar Materials science Lab Department of Applied Physics G. J. University of Science and Technology Hisar-125001 India Department of physics Chaudhary Devi Lal University Sirsa-125055 India

Neodymium （binary oxide） powders are synthesized by a solgel technique. prepared powders are heat treated under different temperature/or different time duration and obtained nanostructure of Nd. Metal particle have diameters in the range 7.8-1.6 nm. It is found that the heat treatment plays an important role to produce different structure of Nd-doped silica matrix. The peak position shifts to lower angle as the size of the nano metal oxide particles size increases.

关键词： INTERFACEs (physical sciences) NEODYMIUM METALLIC oxides METALs -- Heat treatment NANOsTRUCTUREs sILICA

Non-spherical Gravitational Collapse of strange Quark Matter

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Chinese physics Letters 2008年第5期25卷 1568-1570页

作者： Zade s s patil K D Mulkalwar p N Department of Mathematics J. B. College of Science Wardha India Department of Mathematics B. D. College of Engineering Sewagram Wardha India Department of Computer science Amolakchand Mahavidyalaya Yavatmal India

We study the non-spherical gravitational collapse of the strange quark null fluid. The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole. We extend the earlier work of Harko and Cheng [phys. Lett. A 266 （2000） 249] to the non-spherical case.

关键词： NAKED sINGULARITIEs COsMIC CENsORsHIp spACETIMEs

Multi-year MODIs active fire type classification over the Brazilian Tropical Moist Forest Biome

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International Journal of Digital Earth 2017年第1期10卷 54-84页

作者： D.p.Roy s.s.Kumar Geospatial sciences Center of Excellence South Dakota State UniversityBrookingsSDUSA

The Brazilian Tropical Moist Forest Biome(BTMFB)spans almost 4 million km^(2) and is subject to extensive annual fires that have been categorized into deforestation,maintenance,and forest fire *** on fire types is important as they have different atmospheric emissions and ecological impacts.A supervised classification methodology is presented to classify the fire type of MODerate resolution Imaging spectroradiometer(MODIs)active fire detections using training data defined by consideration of Brazilian government forest monitoring program annual land cover maps,and using predictor variables concerned with fuel flammability,fuel load,fire behavior,fire seasonality,fire annual frequency,proximity to surface transportation,and local *** fire seasonality,local temperature,and fuel flammability were the most influential on the *** fire type results for all 1.6 million MODIs Terra and Aqua BTMFB active fire detections over eight years(2003–2010)are presented with an overall fire type classification accuracy of 90.9%(kappa 0.824).The fire type user’s and producer’s classification accuracies were respectively 92.4%and 94.4%(maintenance fires),88.4%and 87.5%(forest fires),and,88.7%and 75.0%(deforestation fires).The spatial and temporal distribution of the classified fire types are presented and are similar to patterns reported in the available recent literature.

关键词： Earth observation land cover remote sensing

Rock mechanical investigation of strata loading characteristics to assess caving and requirement of support resistance in a mechanized powered support longwall face

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International Journal of Mining science and Technology 2016年第6期26卷 1081-1087页

作者： Aveek Mangal p.s.paul Department of Mining Engineering Indian Institute of Technology(Indian School of Mines)Dhanbad826004JharkhandIndia

Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.

关键词： Longwall mining Geo-mechanics Caving behaviour support resistance

Multi-Headed Deep Learning Models to Detect Abnormality of Alzheimer’s patients

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Computer systems science & Engineering 2023年第1期44卷 367-390页

作者： s.Meenakshi Ammal p.s.Manoharan Department of Electrical and Electronics Engineering Thiagarajar College of EngineeringMadurai625015Tamil NaduIndia

Worldwide,many elders are suffering from Alzheimer’s disease(AD).The elders with AD exhibit various abnormalities in their activities,such as sleep disturbances,wandering aimlessly,forgetting activities,etc.,which are the strong signs and symptoms of AD *** these symptoms in advance could assist to a quicker diagnosis and treatment and to prevent the progression of Disease to the next *** proposed method aims to detect the behavioral abnormalities found in Daily activities of AD patients(ADp)using *** the proposed work,a publicly available dataset collected using wearables is ***,no real-world data is available to illustrate the daily activities of ***,the proposed method has synthesized the wearables data according to the abnormal activities of *** the proposed work,multi-headed(MH)architectures such as MH Convolutional Neural Network-Long short-Term Mem-ory Network(CNN-LsTM),MH one-dimensional Convolutional Neural Network(1D-CNN)and MH two dimensional Convolutional Neural Network(2D-CNN)as well as conventional methods,namely CNN-LsTM,1D-CNN,2D-CNN have been implemented to model activity pattern.A multi-label prediction technique is applied to detect abnormal *** results obtained show that the proposed MH architectures achieve improved performance than the conventional ***,the MH models for activity recognition perform better than the abnormality detection.

关键词： Alzheimer’s disease abnormal activity detection classifier chain multi-headed CNN-LsTM wearable sensor

Global operational land imager Landsat-8 reflectance-based active fire detection algorithm

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International Journal of Digital Earth 2018年第2期11卷 154-178页

作者： s.s.Kumar D.p.Roy plant and Environmental sciences New Mexico State UniversityLas CrucesNMUSA Geospatial sciences Center of Excellence South Dakota State UniversityBrookingsSDUSA

A global operational land imager(GOLI)Landsat-8 daytime active fire detection algorithm is *** utilizes established contextual active fire detection approaches but takes advantage of the significant increase in fire reflectance in Landsat-8 band 7(2.20μm)relative to band 4(0.66μm).The detection thresholds are fixed and based on a statistical examination of 39 million non-burning Landsat-8 ***-temporal tests based on band 7 reflectance and relative changes in normalized difference vegetation index in the previous six months are used to reduce commissions *** probabilities of active fire detection for the GOLI and two recent Landsat-8 active fire detection algorithms are simulated to provide insights into their performance with respect to the fire size and *** algorithms are applied to 11 Landsat-8 images that encompass a range of burning conditions and *** and omission errors are assessed by visual interpretation of detected active fire locations and by examination of the Landsat-8 images and higher spatial resolution Google Earth *** GOLI algorithm has lower omission and comparable commission errors than the recent Landsat-8 active fire detection *** GOLI algorithm has demonstrable potential for global application and is suitable for implementation with other Landsat-like reflective wavelength sensors.

关键词： Earth observation remote sensing visible/infrared remote sensing

Chalcopyrite solar cells——state-of-the-art and options for improvement

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science China(physics,Mechanics & Astronomy) 2023年第1期66卷 3-17页

作者： s.siebentritt T.p.Weiss Laboratory for photovoltaics Department of Physics and Materials ScienceUniversity of LuxembourgBelvaux 4422Luxembourg

Chalcopyrite solar cells will have to play an important role to mitigate the climate crisis,because of their particularly low carbon *** in these semiconductors is due to native defects and intentional alkali *** recent progress in efficiency has been made possible by post-deposition treatments with heavy *** states and band gap distribution are the main limitations for the open circuit voltage in state-of-the-art chalcopyrite solar *** efficiency limitations are due to the increased diode factor because of metastable defect *** with Ag opens new possibilities of band-edge engineering,as well as seems to improve the diode *** state-of-the-art cells the back contact is passivated by a Ga gradient;considerable research has been done to passivate the back contact by structured or continuous dielectric layers.A leap forward in efficiency can be expected from tandem *** solar cells show promising potential as bottom cells as well as top cells.

关键词： doping tail states alkali treatment efficiency

Mapping of bauxite mineral deposits in the northern region of saudi Arabia by using Advanced spaceborne Thermal Emission and Reflection Radiometer satellite data

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Geo-spatial Information science 2019年第1期22卷 35-44页

作者： p.sheik Mujabar s.Dajkumar Department of General studies Jubail Industrial CollegeJubailSaudi Arabia Exploration Geoscience PerthAustralia

Mineral deposit mapping is very essential for sustainable and eco-friendly exploitation of natural *** Kingdom of saudi Arabia has abundant natural resources such as natural gas,oil and *** reserves high quantity of minerals such as phosphates,bauxites,copper,gold and other industrial *** red soil regions located in Hail and Qassim provinces of saudi Arabia have rich amount of bauxite(major aluminum ore)*** order to initiate the focus on mapping of mineral deposits along this area,standardized hyper-spectral analysis has been carried out by using Advanced spaceborne Thermal Emission and Reflection Radiometer(AsTER)satellite *** spectral signature of gibbsite(major element in bauxite)samples is analyzed with reference to the spectral features of gibbsite in the visible near infrared and short-wave infrared bands electromagnetic *** hyper-spectral transformations such as minimum noise fraction function and pixel purity index have been performed to identify the target *** existence of the mineral is confirmed by comparing the spectral signatures of the endmember with the predefined spectral plots of AsTER and United states Geological survey spectral ***,the end-members are mapped and their abundance is estimated in 0–1 *** study has opened up new areas for mapping of bauxite deposits in the area and leads to eco-friendly exploitation of natural *** also validates the high potential of AsTER multispectral satellite data for the exploration and mapping of mineral resources.

关键词： Mineralogy geology remote sensing saudi Arabia