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Characterization and beneficiation of the Egyptian black shale for possible extraction of organic matter

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International Journal of Mining Science and Technology 2014年第2期24卷 177-182页

作者： Abd El-Rahiem F.H. Hassan M.S. selim k.a. Abdel-k.a.ek N.A. Central Metallurgical Research and Development Institute

The present paper focuses on obtaining concentrate enriched with organic matter that could be suitable for a retorting process from black shale; this is black shale from the Safaga area on the Red Sea Coast. X-ray diffraction and optical polarising microscope are used in evaluating black shale minerals. Attrition scrubbing and flotation were conducted for enrichment of organic matter in the black shale sample. Mineralogical studies revealed that black shale samples contain bituminous calcareous clay stone, quartz, apatite and pyrite. Rabah mine black shale contains 28% organic matter. The results of the different separation techniques indicate that attrition and flotation techniques successively enriched the organic matter in the black shale. The organic matter could be enriched in the black shale and obtained a concen- trate with 59% assavinz and 85% recovery.

关键词： Black shale kerogen Organic matter Attrition scrubbing Flotation

CAVITATION NUCLEI:EXPERIMENTS AND THEORY

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Journal of Hydrodynamics 2009年第2期21卷 176-189页

作者： MφRCH k.a. Department of Physics and Center of Quantum Protein DK-2800 Kongens LyngbyDenmark

The Swedish astrophysicist and Nobel Prize winner Hannes Alfven said： Theories come and go -- the experiment is here forever. Often a theory, which we set up to describe an observed physical phenomenon, suffers from the lack of knowledge of decisive parameters, and therefore at best the theory becomes insufficient. Contrary, the experiment always reveals nature itself, though at prevailing experimental conditions. With essential parameters being out of control and even maybe unidentified, apparently similar experiments may deviate way beyond our expectations. However, these discrepancies offer us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character.

关键词： cavitation nuclei gas bubbles surface nano voids scanning tunneling microscopy atomic force microscopy

Stability of multiple fans in mine ventilation networks

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International Journal of Mining Science and Technology 2013年第4期23卷 558-560页

作者： El-Nagdy k.a. Mining Engineering Department Faculty of Petroleum and Mining Engineering Suez Canal University

In large mines,single fan is usually not enough to ventilate all the working *** mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the ***,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem *** some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan *** this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters *** show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.

关键词： Mine ventilation Multiple fan ventilated network Hardy Cross algorithm Switching parameters technique Abu-Tartur Mine

Microstructural Development and Deformation Mechanisms during Cold Rolling of a Medium Stacking Fault Energy TWIP Steel

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Journal of Materials Science & Technology 2013年第2期29卷 161-167页

作者： k.a. Ofei L. Zhao J. Sietsma Materials Innovation Institute M2i Mekelweg 2 2628 CD Delft The Netherlands Department of Materials Science and Engineering Delft University of Technology Mekelweg 2 2628 CD Delft The Netherlands

The magnetic response, microstructural and texture changes occurring during cold rolling of a Fe-14Mn-0.64C-2.4AI-0.25Si medium stacking fault energy TWlP （twinning induced plasticity） steel have been studied by X-ray diffraction and magnetic techniques. The changes in the sub-grain size （Ds）, probability of stacking fault formation （Psf） and microstrain in the material as cold rolling progressed were determined by using a modified version of the Williamson and Hall equation. A strong development of the crystallographic texture with increasing deformation was observed. Deformation-induced formation of a small fraction α＇-martensite was observed, indicating that the steel also exhibits γ→α＇-martensite transformation during cold rolling, which is discussed via the changes of the stacking-fault probability and the texture development during cold rolling.

关键词： TWIP steel α'-Martensite Sub-grain size Probability of stacking fault formation Texture development

Digital Identification of Ecosystem Structure in the FIrtIna Valley of the kakar Mountains in the Rize City of Turkey

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Journal of Mountain Science 2014年第2期11卷 421-428页

作者： Cagasan kARACAOGLU selim Sualp CAGLAR Department of Biology Faculty of Science Biology Department Ecology Section EBAL Laboratories Hacettepe University

Identifying the structure of protected mountain ecosystems is an important task for understanding conservation sustainability. The study area, the Firtina Valley, located in the Rize City on the Eastern Blacksea Coast, is one of the biological hotspots and a National Park of Turkey. In order to identify the structure of mountain ecosystems, we generated a GIS database for the main environmental parameters of the study area, including elevation,slope and aspect layers for topographic structure, 10year mean values of Normalized Difference Vegetation Index(NDVI), data for vegetation structure, annual mean temperature and precipitation layers for climatic structure, main soil groups for soil structure and stream flow accumulation, stream flow length and stream order layers for hydrological *** identify the complex relations among environmental factors in the study area a data reduction method is applied with Principal Component Analysis(PCA). PCA is performed using data of 16 layers from Geographical Information Systems(GIS). PCA analysis reduced 16 dimensions into 5 dimensions containing 75% of the variation in all data. It is also revealed that the topographic structure, mainly altitude, dominates the ecosystems of the Firtina Valley, but it should be considered that the interactions of environmental factors in an ecosystem dynamics are very complex. The ecosystem structure is determined by the environmental factors direct or indirect effects on energy regulation of an ecosystem. Therefore the relationship between topographic elements and other abiotic-biotic elements in the Firtina Valley are important for environmental assessment and sustainability of a protected area, and these effects are explained in this study.

关键词： PCA GIS Firtina Valley Ecosystem structure Protected areas

Determination of penetration depth at high velocity impact using finite element method and artificial neural network tools

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Defence Technology（防务技术） 2015年第2期11卷 110-122页

作者： Nam?k kILI? Blent EkICI selim HARTOMACIOG LU Computer Aided Engineering Department Otokar Otomotiv ve Savunma San.A.SAtaturk Cad No: 9 Arifiye54580SakaryaTurkey Department of Mechanical Engineering Faculty of EngineeringMarmara University Department of Mechanical Engineering Faculty of Mechanical EducationMarmara University

Determination of ballistic performance of an armor solution is a complicated task.a.d evolved significantly with the application of finite element methods(FEM) in this research *** traditional armor design studies performed with FEM requires sophisticated procedures and intensive computational effort,therefore simpler and accurate numerical approaches are always worthwhile to decrease armor development *** study aims to apply a hybrid method using FEM simulation and artificial neural network.a.N) analysis to approximate ballistic limit thickness for armor *** achieve this objective,a predictive model based on the artificial neural networks is developed to determine ballistic resistance of high hardness armor steels against 7.62 mm armor piercing *** this methodology,the FEM simulations are used to create training cases for Multilayer Perceptron(MLP) three layer *** order to validate FE simulation methodology,ballistic shot tests on 20 mm thickness target were performed according to standard Stanag ***,the successfully trained ANN(s) is used to predict the ballistic limit thickness of 500 HB high hardness steel *** show that even with limited number of data,FEM-ANN approach can be used to predict ballistic penetration depth with adequate accuracy.

关键词：人工神经网络有限元法穿透深度性能测定高速冲击有限元模拟 FEM模拟工具

Strength properties of xanthan gum and guar gum treated kaolin at different water contents

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1160-1172页

作者： Irem Bozyigit Ak.a. Javadi selim Altun Department of Civil Engineering Ege UniversityBornova-IzmirTurkey College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeterUK

Nowadays,using biopolymer as a ground improvement method has become very ***,since biopolymers are organic and degradable,their long-term effect is not fully *** this study,the effects of biopolymers on the mechanical behavior of kaolin clay were investigated through a comprehensive program of *** types of biopolymer,*** gum and guar gum were chosen to investigate the effect of biopolymer *** this purpose,specimens were prepared using standard Proctor energy at four different water contents(25%,30%35%and 40%)with 0.5%,1%,1.5%and 2%biopolymer *** specimens were cured for 1 d,7 d,28 d and 90 ***,some of the specimens were kept in the curing room for 3 years to observe the long-term effect of the *** the end of the curing periods,the specimens were subjected to unconfined compression test,and scanning electron microscopy(SEM)analysis was performed to observe the mechanism of strength *** results revealed that the unconfined compressive strength(UCS)of the specimens treated with biopolymers increased in all biopolymer inclusion levels and water contents up to a 90-d curing *** specimens containing xanthan gum,the maximum strength increase was observed at 25%water content and 2%xanthan gum with 90-d *** strength increased 5.23 times induced by xanthan gum addition when compared to the pure ***,the increase in strength reached 8.53 times in specimens treated with guar ***,increasing water content caused more ductile behavior,thus increasing the axial deformation.

关键词： Biopolymer Clay Unconfined compressive strength(UCS) Xanthan gum Guar gum Strength properties

Humidity and seasonality drives body size patterns in males of the bush cricket Isophya rizeensis Sevgili, 2003 （Orthoptera： Tettigoniidae： Phaneropterinae）

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Insect Science 2014年第2期21卷 213-226页

作者： selim S. Cagasan Cagasan karacaoglu A. Cem kuyucu ismail k. Saelam Department of Biology Ecological Sciences Research Laboratories Faculty of Science Hacettepe University Beytepe 06800 Ankara Turkey

Two primary patterns of body size variation have been recorded in ectotherms in relation to latitudinal/altitudinal shifts. In some, body size increases with increasing latitude/altitude whereas, in others, body size decreases with increasing latitude/altitude. This clinal variation is generally assumed to be caused by local adaptation to environmental conditions however the selective variable（s）（temperature, humidity, diet quality, etc.） is still heavily debated. Here we investigate geographic variation in body size of dark.a.d pale color morphs of males of the bush-cricket lsophya rizeensis collected from 15 locations along an elevation gradient ranging from 350 to 2 500 m. Using an information theoretical approach we evaluate the relative support of four different hypotheses （the temperature size rule, the moisture gradient hypothesis, the seasonal constraint hypothesis, and the primary productivity hypothesis） explaining body size variation along the altitudinal gradient. Body size variation in pale color morphs showed a curvilinear relationship with altitude while dark color morphs showed no variation in body size. Body size variation in pale color morphs was highly correlated with precipitation and temperature seasonality values thus giving strong support for the moisture gradient and seasonal constraint hypothesis. Our results reinforce the importance of gradients in humidity and seasonality over temperature in the creation of altitudinal body size clines and the role of selection for resistance to stress factors in the establishment of these clines. Whether a body size cline is observed or not might also depend on the phenotypic properties of the individuals, like coloration.

关键词： altitude Bergmann's rule converse Bergmann's rule Flrtlna Valley,information-theoretic temperature size rule

Recursive harmonic analysis for computing Hansen coefficients

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Research in Astronomy and Astrophysics 2010年第12期10卷 1298-1306页

作者： Mohamed Adel Sharaf Hadia Hassan selim Astronomy Department Faculty of Science King Abdul Aziz University Astronomy Department National Research Institute of Astronomy and Geophysics

We report on a simple pure numerical method developed for computing Hansen coefficients by using a recursive harmonic analysis technique. The precision criteria of the computations are very satisfactory and provide materials for computing Hansen＇s and Hansen＇s like expansions, and also to check the accuracy of some existing algorithms.

关键词： celestial mechanics -- methods: numerical