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Flotation studies on low grade graphite ore from eastern India

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International journal of Mining science and technology 2015年第3期25卷 415-420页

作者： vasumathi N. vijaya Kumar t.v. Ratchambigai s. subba Rao s. Bhaskar Raju G. CsIR-National Metallurgical Laboratory Madras Centre CSIR Madras Complex

A low grade graphite ore from eastern India was beneficiated by flotation to improve its quality. the ore was composed of 87.80%ash and 8.59%fixed carbon. Primary coarse wet grinding （d80：186 μm） followed by rougher flotation in Denver flotation cell using diesel as collector and pine oil as frother yielded a rougher concentrate. Regrinding （d80：144 μm） of this rougher concentrate was opted for further libera-tion of graphite. It was followed by cleaning in laboratory flotation column. this combined process of relatively coarse primary grinding followed by regrinding and cleaning in flotation column resulted in final concentrate of 7.44% yield with 89.65% fixed carbon and 6.00% ash. this approach of two-stage grinding to recover the flake graphite at the coarsest possible grind can help to minimize grinding energy costs. A conceptual flow sheet which is cost effective was developed based on this methodology.

关键词： Graphite Liberation Froth flotation Column flotation Flow-sheet development

Morphology,structure and magnetic behavior of orthorhombic and hexagonal HoFeO_(3)synthesized via solution combustion approach

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journal of Rare Earths 2022年第2期40卷 296-301,I0004页

作者： K.D.Martinson I.s.Kondrashkova M.I.Chebanenko A.s.Kiselev t.Yu Kiseleva v.I.Popkov Ioffe Institute 26 PoliteknicheskayaSL Petersburg194021Russia saint Petersburg state Institute of technology 26 MoskovskySt.Petersburg190013Russia Faculty of Physics M.V.Lomonosov State UniversityLeninskie CoryMoscow119991Russia

Nanostructured HoFeO_(3)powders were obtained by solution combustion method at various glycinenitrate ratios(G/N=0.2,0.4,...,1.4).According to X-ray powder diffractometry data,the presence of two modifications of HoFeO_(3)in the synthesized samples was established:orthorhombic(Pbnm)and hexagonal(P63/mmc).the crystallite size of the obtained compositions varies from 62±6 to 29±3 nm,depending on the G/N *** magnetic structure studies,it is found that HoFeO_(3)obtained with a stoichiometric amount of glycine in the reaction solution is in the magnetically ordered state and is represented by a sextet with quadrupole splitting(Qs)=0 mm/s,isomeric shift(Is)=0.36 mm/s and effective field strength(Heff)=497 *** to the results of vibrational magnetometry,it is found that the orthoferrites obtained have a ferromagnetic structure,the main parameters of which(Ms,Mr and Hc)systematically change with a change in the redox ratio of the reaction mixture and,as a consequence,their phase composition,and reach maximum values at a G/N ratio=*** the samples obtained with a significant excess and lack of glycine(G/N=0.2 and 1.4),despite their amorphous nature,hysteresis loops characteristic of the ferromagnetic state of the substance is *** is hopeful to obtain a pure hexagonal modification of HoFeO_(3)via heat treatment on amorphous products of glycine-nitrate combustion.

关键词： Crystal structure Rare earth compounds Perovskites Nanomaterials Magnetic materials

Us-Russian Civilian Research and Development Fund Project： An origin of microdiamonds in metamorphic rocks of the Kokchetav Massif, Northern Kazakhstan

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Episodes 2003年第4期26卷 290-294页

作者： N.v.sobolevt v.s.shatsky j.G.Liou R.Y.Zhang s.L.Hwang P.shen H.t.Chu t.F.Yui A.A.Zayachkovsky M.A.Kasymov UnitedInstituteofGeology GeophysicsandMineralogySiberianBranchofRussianAcademyofScienceNovosibirsk630090Russia DepartmentofGeologicalandEnvironmentalsciences StanfordUniversityStanfordCA94305USA DepartmentofMaterialsscienceandEngineering NationalDongHwaUniversityHualienTaiwanChina InstituteofMaterialsscienceandEngineering NationalSunYat-senUniversityKaohsiungTaiwanChina CentralGeologicalsurvey P.O.Box968TaipeiTaiwanChina InstituteofEarthsciences AcademiaSinicaTaipeiTaiwanChina NEDRAGeologicalExpedition 475013KokchetavKazakhstan InstituteofGeologicalsciences AcademyofSciencesoftheRepublicofKazakhstanAlmaty480100Kazakhstan

the Kokchetav Massif of northern Kazakhstan is a typelocality of occurrence of microdiamonds in ultrahighpressure metamorphic" rocks. It records continental subduction and exhumation from depths greater than 120 km and provides unparalleled insights into mantle dynamics, global material recycling and the processes responsible for the genesis and destruction of continent. through the support of a Us Civilian Development and Research Fund, a group of Russian, Us, taiwan Residents and Kazakhstan geologists visited the reconstructed 800-m underground gallery to conduct field survey and sample collections. this gallery provides a useful geologic laboratory for international community to undertake similar geotectonic or different ecological and environmental studies.

关键词：变质岩地质调查动力学俄罗斯美国

three-dimensional analysis of a faulted CO2 reservoir using an Eshelby-Mori-tanaka approach to rock elastic properties and fault permeability

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journal of Rock Mechanics and Geotechnical Engineering 2016年第6期8卷 828-845页

作者： ba Nghiep Nguyen Zhangshuan Hou George v.Last Diana H.bacon Pacific Northwest National Laboratory RichlandWAUSA

this work develops a three-dimensional(3D) multiscale model to analyze a complex carbon dioxide(CO_2) faulted reservoir that includes some key geologic features of the san Andreas and nearby faults southwest of the Kimberlina *** model uses the stOMP-CO2 code for flow modeling that is coupled to the AbaQUs~ finite element package for geomechanical analysis.A 3D AbaQUs~ finite element model is developed that contains a large number of 3D solid elements with two nearly parallel faults whose damage zones and cores are discretized using the same continuum *** zones with different mineral compositions are considered:shale,sandstone,fault damaged sandstone,fault damaged shale,and fault ***' elastic properties that govern their poroelastic behavior are modeled by an Eshelby-Mori-tanaka approach(EMtA).which can account for up to 15 mineral *** permeability of fault damage zones affected by crack density and orientations is also predicted by an EMtA formulation.A stOMP-CO2 grid that exactly maps the AbaQUs~ finite element model is built for coupled hydromechanical *** of the reservoir assuming three different crack pattern situations(including crack volume fraction and orientation) for the fault damage zones are performed to predict the potential leakage of CO_2 due to cracks that enhance the permeability of the fault damage *** results illustrate the important effect of the crack orientation on fault permeability that can lead to substantial leakage along the fault attained by the expansion of the CO_2 *** hydraulic fracture and tendency for the faults to slip are also examined and discussed in terms of stress distributions and geomechanical properties.

关键词： Carbon dioxide(CO_2) reservoir Geomechanical modeling Mineralogy Homogenization Fault Leakage slip Elastic properties

trace element geochemistry and sr-Nd characteristics of Mesoproterozoic mafic intrusive rocks from Rondonia, Brazil, sW Amazonian Craton： Petrogenetic and tectonic inferences

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Episodes 2008年第4期31卷 392-400页

作者： Girardi, v.A. v. teixeira, W. Bettencourt, j.s. Andrade, s. Navarro, M.s. sato, K. Instituto de Geociencias Universidade de Sao Paulo Rua do Lago 562. CEP 05508-080 Cidade Universitada S. Paulo Brazil

the Amazonian Craton comprises an Archean domain surrounded by four successively younger Proterozoic tectonic provinces. Within the Rio-Negro-juruena province the serra da Providencia Intrusive suite （1.60 and 1.53 Ga） consists of A-type rapakivi gran- ites, charnockites and mangerites genetically associated with diabase dikes, gabbros and amphibolites. the original mafic melts were derived from a depleted mantle source （εN（t）＋2.5 to ＋2.8;εsr（t） -12.1）. Underplated mafic magma induced melting of a short-lived felsic crust, thus originating coeval felsic-mafic magmatism in a conti- nental intraplate setting. the Colorado Complex, assigned to the Rondonian-san Ignacio province, comprises 1.35-1.36 Ga intrusive bimodal magmatism represented by monzonite gneisses associated with amphibolite, gabbro and metadiabase dikes intercalated with metasediments with detrital zircon that yield U- Pb ages of 1.35 to 1.42 Ga. Mafic samples dis- play juvenile signatures （εNd（t） 0.0 to ＋5.2; εsr（t） --5.0 to --30.7） and are less contaminated than the serra da Previdencia and Nova Brasilandia ones. the generation of the basaltic magma is related to the subduction of an oceanic slab below the peridotite wedge （intraoceanic arc setting）. Fluids and/or small melts from the slab impregnated the mantle. the Nova Brasilandia sequence （sunsas-Aguapef province） comprises a metasedimentary sequence intruded by 1.10-1.02 Ga metadia- bases, gabbros, meta-gabbros, and amphibolites associated with granitic plutons （bimodal mag- matism）. the original tholeiitic magmas, derived from a depleted source （εNd（t） = ＋3.1 to ＋5.0）, in a proto-oceanic setting, underwent subsequent contamination by the host rocks, as indicated by the isotopic and trace element data.

关键词：亚马逊河流域巴西 sr-Nd特性地球化学

synthesis, characterization and biocompatibility studies of zinc oxide(ZnO) nanorods for biomedical application

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Nano-Micro Letters 2010年第1期2卷 31-36页

作者： R.Gopikrishnan K.Zhang P.Ravichandran s.baluchamy v.Ramesh s.Biradar P.Ramesh j.Pradhan j.C.Hall A.K.Pradhan G.t.Ramesh Molecular toxicology Laboratory Center for Biotechnology and Biomedical Sciences Norfolk State University Center for Materials Research Norfolk State University Health science Academy Bayside High School Virginia Beach

Nanoparticles are increasingly being recognized for their potential utility in biological applications including ***,we have synthesized zinc oxide(ZnO)nanorods using zinc acetate and hexamethylenetetramine as precursors followed by characterizing using X-ray diffraction,fourier transform infrared spectroscopy,scanning electron microscopy and transmission electron *** growth of synthesized zinc oxide nanorods was found to be very close to its hexagonal nature,which is confirmed by X-ray *** nanorod was grown perpendicular to the long-axis and grew along the[001]direction,which is the nature of ZnO *** morphology of synthesized ZnO nanorods from the individual crystalline nucleus was confirmed by scanning and transmission electron *** length of the nanorod was estimated to be around 21 nm in diameter and 50 nm in *** toxicology studies showed that synthesized ZnO nanorods exposure on hela cells has no significant induction of oxidative stress or cell death even in higher concentration(10μg/ml).the results suggest that ZnO nanorods might be a safer nanomaterial for biological applications.

关键词： Zinc oxide [ZnO] Nanorods XRD sEM & tEM Cytotoxicity

Inhomogeneous dealloying kinetics along grain boundaries during liquid metal dealloying

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journal of Materials science & technology 2022年第11期106卷 41-48页

作者： s.-H.joo Y.B.jeong t.Wada I.v.Okulov H.Kato Department of Materials science and Engineering Dankook University119 Dandae-roCheonan 31116Korea Institute for Materials Research Tohoku UniversityKatahira 2-1-1Sendai 980-8577Japan Institute of Natural sciences and Mathematics Ural Federal University620000 EkaterinburgRussia Faculty of Production Engineering University of BremenBadgasteiner Str.128359 BremenGermany Leibniz Institute for Materials Engineering-IWt Badgasteiner Str.328359 BremenGermany

In this study, the inhomogeneous dealloying phenomenon during the liquid metal dealloying(LMD) was investigated using FeNi+Mg and(FeCo)Ni+Mg systems. For the FeNi+Mg system, the inhomogeneous dealloying and wetting of Mg melt occurred along triple junction(tj) and grain boundary(GB).temperature increase enhances the inhomogeneous dealloying kinetics and leads to the formation of the plate-shaped abnormal ligaments at the GB region. the energy banlance between a GB energy(γGB)and solid-liquid interface energies(γsl) is the key factor governing the inhomogeneous dealloying and wetting. Particularly, the low-energy twin boundaries were unaffected by the inhomogeneous ***, precursor microstructure is an important factor determining the final morphology of dealloyed material as well as its physical properties. In the case of the(FeCo)Niprecursor, all tj and GB were stable against the preferred penetration of Mg melt from 600 ℃ to 800 ℃. It was concluded that a minor addition of alloying elements(vorCr) changes GB characteristics as well as γslof the precursor ***, this significantly influences dealloying mechanisms and final morphology of the dealloyed material. the current findings demonstrate the importance of GB engineering in the precursor materials for the technological application of liquid metal dealloying for the synthesis of advanced structural and functional materials.

关键词： Liquid metal dealloying Inhomogeneous dealloying Dealloying mechanism Abnormal ligament Porous material

Object-based Method Outperforms Per-Pixel Method for Land Cover Classification in a Protected Area of the Brazilian Atlantic Rainforest Region

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Pedosphere 2013年第3期23卷 290-297页

作者： t.RIttL M.COOPER R.j.HECK M.v.R.baLLEstER Department of soil Quality University of Wageningen Department of soil science University of So Paulo school of Environmental sciences University of Guelph Center for Nuclear Energy in Agriculture (CENA) University of So Paulo

Conventional image classification based on pixels hinders the possibilities to obtain information contained in images, while modern object-based classification methods increase the acquisition of information about the object and the context in which it is inserted in the image. the objective of this study was to investigate the performance of different classification methods for land cover mapping in the vicinity of the Alto Ribeira tourist state Park, a Brazilian Atlantic rainforest area. two classification methods were tested, including i） a hybrid per-pixel classification using the image processing software ERDAs Imagine version 9.1 and ii） an object-based classification using the software eCognition version 5. In the first method, six different classes were established, while in the second method, another two classes were established in addition to the six classes in the first method. Accuracy assessment of the classification results presented showed that the object-based classification with a Kappa index value of 0.8687 outperformed the per-pixel classification with a Kappa index value of 0.2224. Application of the user＇s knowledge during the object-based classification process achieved the desired quality; therefore, the use of inter-relationships between objects, superelasses, subclasses, and neighboring classes were critical to improving the efficiency of land cover classification.

关键词： accuracy assessment image classification Kappa index user's knowledge

Clinical significance of lymphadenectomy in patients with gastric cancer

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World journal of Gastrointestinal Oncology 2016年第2期8卷 136-146页

作者： dezso tóth jános plósz miklós torok department of general surgery kenézy teaching hospital4043 DebrecenHungary department of internal medicine kenézy teaching hospital4043 Debrecen Hungary department of pathology kenézy teaching hospital4043 Debrecen Hungary

Approximately thirty percent of patients with gastric cancer undergo an avoidable lymph node dissection with a higher rate of postoperative complication. Comparing the D1 and D2 dissections,it was found that there is a significant difference in morbidity,favoured D1 dissection without any difference in overall survival. subgroup analysis of patients with t3 tumor shows a survival difference favoring D2 lymphadenectomy,and there is a better gastric cancer-related death and non-statistically significant improvement of survival for node-positive disease in patients with D2 dissection. However,the extended lymphadenectomy could improve stage-specific survival owing to the stage migration phenomenon. the deployment of centralization and application of national guidelines could improve the surgical outcomes. the japanese and European guidelines enclose the D2 lymphadenectomy as the gold standard in R0 resection. In the individualized,stageadapted gastric cancer surgery the Maruyama computer program(MCP) can estimate lymph node involvement preoperatively with high accuracy and in addition the Maruyama Index less than 5 has a better impact on survival,than D-level guided surgery. For these reasons,the preoperative application of MCP is recommended routinely,with an aim to perform "low Maruyama Index surgery". the sentinel lymph node biopsy(sNB) may decrease the number of redundant lymphadenectomy intraoperatively with a high detection rate(93.7%) and an accuracy of 92%. More accurate stage-adapted surgery could be performed using the MCP and sNB in parallel fashion in gastric cancer.

关键词： Gastric cancer surgery Lymphadenectomy sentinel node biopsy Maruyama computer program