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Sample records for high grade ore

  1. Underground Milling of High-Grade Uranium Ore

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, C., E-mail: chuck.edwards@amec.com [AMEC Americas Limited, Saskatoon, Saskatchewan (Canada)

    2014-05-15

    There are many safety and technical issues involved in the mining and progressing of high grade uranium ores such as those exploited in Northern Canada at present. With more of this type of mine due to commence production in the near future, operators have been looking at ways to better manage the situation. The paper describes underground milling of high-grade uranium ore as a means of optimising production costs and managing safety issues. In addition the paper presents some examples of possible process flowsheets and plant layouts that could be applicable to such operations. Finally an assessment of potential benefits from underground milling from a variety of viewpoints is provided. (author)

  2. An innovative jet boring mining method available for the high grade uranium ore underground deposits

    International Nuclear Information System (INIS)

    Narcy, J.L.

    1996-01-01

    An innovative mining method, based on the capability of a high pressure water jet to desaggregate rock, has been conceived and tested with success at the highest grade uranium ore deposit in the world, the Cigar Lake deposit in Saskatchewan, Canada. 113 tonnes of ore at 13% U were mined out by a new jet-boring mining method operated on a semi-industrial basis, in 1992 during the test mining program of Cigar Lake Project. (author). 9 figs

  3. The separation of ore from cooke into high- and low-grade fractions

    International Nuclear Information System (INIS)

    Guest, R.N.

    1984-01-01

    The separation of the ore by sizing alone was not very successful, and the recovery of uranium to the high-grade fraction did not exceed 73 per cent. The use of a combination of size and gravity separation was attempted, and the tailing from the gravity circuit contained 33,9 per cent of the uranium at a grade of 60g/t. The circuit recommended includes autogenous grinding to liberate part of the ore matrix containing the values into the fine fraction. This should be followed by heavy-medium separation for the recovery of the high-grade portion of the coarse fraction. The size at which this heavy-medium separation is carried out should be determined

  4. PHASE ANALYSES OF URANIUM BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    International Nuclear Information System (INIS)

    Ren, M.; Goodell, P.; Kelts, A.; Anthony, E.Y.; Fayek, M.; Fan, C.; Beshears, C.

    2005-01-01

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions

  5. Biomineral processing of high apatite containing low-grade indian uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Abhilash; Mehta, K.D.; Pandey, B.D., E-mail: biometnml@gmail.com [National Metallurgical Laboratory (CSIR), Jamshedpur (India); Ray, L. [Jadavpur Univ., FTBE Dept., Kolkata (India); Tamrakar, P.K. [Uranium Corp. of India Limited, CR& D Dept., Jaduguda (India)

    2010-07-01

    Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U{sub 3}O{sub 8}), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35{sup o}C using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35{sup o}C. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

  6. Biomineral processing of high apatite containing low-grade indian uranium ore

    International Nuclear Information System (INIS)

    Abhilash; Mehta, K.D.; Pandey, B.D.; Ray, L.; Tamrakar, P.K.

    2010-01-01

    Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U_3O_8), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35"oC using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35"oC. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

  7. Microbial leaching of low grade copper ores

    International Nuclear Information System (INIS)

    Rauf, A.; Ashfaq, M.

    1991-01-01

    Biotechnology is regarded as one of the most promising and revolutionary solution to various problems which are generally faced in the extraction of metals from their ores such as high energy, capital costs and environmental pollution. The paper deals with the study of low grade copper ores for their beneficiation and extraction of copper. The ores used were chalcopyrite and oxidized copper ores. Microorganisms play a vital role in the solubilization of valuable contents from ores such as copper and other metals. Studies have been conducted on the indigenous copper ores by using thiobacillus ferro oxidans and thiobacillus thio oxidans. For comparison purpose some experiments have also been conducted by chemical leaching. The results of bacterial leaching are encouraging. (author)

  8. Ferrite grade iron oxides from ore rejects

    Indian Academy of Sciences (India)

    Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical ...

  9. Processing of low-grade uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1975-01-01

    Four types of low grade ores are studied. Low grade ores which must be extracted because they are enclosed in a normal grade deposit. Heap leaching is the processing method which is largely used. It allows to obtain solutions or preconcentrates which may be delivered at the nearest plant. Normal grade ores contained in a low amplitude deposit which can be processed using leaching as far as the operation does not need any large expensive equipment. Medium grade ores in medium amplitude deposits to which a simplified conventional process can be applied using fast heap leaching. Low grade ores in large deposits. The processing possibilities leading to use in place leaching are explained. The operating conditions of the method are studied (leaching agent, preparation of the ore deposit to obtain a good tightness with regard to the hydrological system and to have a good contact between ore and reagent) [fr

  10. Processing of low grade uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1978-10-01

    Four types of low-grade ores are studied: (1) Low-grade ores that must be extracted because they are enclosed in a normal-grade deposit. Heap leaching is the processing method which is largely used. (2) Normal-grade ores contained in low-amplitude deposits. They can be processed using in-place leaching as far as the operation does not need any large and expensive equipment. (3) Medium-grade ores in medium-amplitude deposits. A simplified conventional process can be applied using fast heap leaching. (4) Low-grade ores in large deposits. The report explains processing possibilities leading in most cases to the use of in-place leaching. The operating conditions of this method are laid out, especially the selection of the leaching agents and the preparation of the ore deposit

  11. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  12. Production of High-purity Magnetite Nanoparticles from a Low-grade Iron Ore via Solvent Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Yong Jae; Kil, Dae Sup; Jang, Hee Dong [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Do, Thi May [Korea University of Science and Technology, Daejeon (Korea, Republic of); Cho, Kuk [Pusan National University, Busan (Korea, Republic of)

    2015-02-15

    We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity Fe{sup 3+} solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of Mg{sup 2+} and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-ore-wastewater treatments, as well as in the economic production of the nano-adsorbent.

  13. Radiation dose control in the mining of high grade uranium ores

    International Nuclear Information System (INIS)

    Webster, S.T.; Brown, L.D.

    1996-01-01

    The control of radiation doses received by uranium miners is an unusually complex procedure, as three separate components of their total effective dose may be significant and may have to be evaluated separately. Apart from external and internal doses evaluated in the usual way, it is also necessary to evaluate the inhalation dose from radon progeny separately. Although this essentially forms part of the internal dose received, it is not evaluated in the conventional way since the associated dose equivalent must be derived from conversion factors based on epidemiological studies, instead of by the usual approach of calculating the dose to tissue from the inhaled activity and multiplying this by a recognized conversion factor to derive a whole body effective dose. Historically the traditional unit used for monitoring the concentration of radon progeny in a workplace is the Working Level (WL), this is now defined as a concentration such that the potential alpha emission from all the short lived progeny present in the sample will total 1.3 x 108 MeV per m 3 . The corresponding unit of exposure is the Working Level Month (WLM) and is the exposure that would be received by a reference man working in such an atmosphere for a standard working month lasting 170 hours. Unfortunately the relationship between exposures, measured in WLM, and the conventional radiation dose to the target tissues is complex and calculated values depend greatly upon the assumptions made in the lung model that must be used. Risks are therefore still controlled by limiting exposures in WLM on the basis of epidemiological studies of lung cancer incidence among miners employed at a time when the magnitude of the risk was not fully appreciated, and cancer incidence was high enough to permit reasonably accurate risk estimates to be derived directly from exposures in WLM. (author)

  14. Uranium mobilization from low-grade ore by cyanobacteria

    International Nuclear Information System (INIS)

    Lorenz, M.G.; Krumbein, W.E.

    1985-01-01

    Three cyanobacterial isolates (two LPP-B forms and one Anabaena or Nostoc species) from different environments could mobilize uranium from low-grade ores. After 80 days, up to 18% uranium had been extracted from coal and 51% from a carbonate rock by the filamentous cyanobacterium OL3, a LPP-B form. Low growth requirements with regard to light and temperature optima make this strain a possible candidate for leaching neutral and alkaline low-grade uranium ores. (orig.)

  15. Uranium mobilization from low-grade ore by cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, M.G.; Krumbein, W.E.

    1985-04-01

    Three cyanobacterial isolates (two LPP-B forms and one Anabaena or Nostoc species) from different environments could mobilize uranium from low-grade ores. After 80 days, up to 18% uranium had been extracted from coal and 51% from a carbonate rock by the filamentous cyanobacterium OL3, a LPP-B form. Low growth requirements with regard to light and temperature optima make this strain a possible candidate for leaching neutral and alkaline low-grade uranium ores.

  16. Beneficiation and leaching study of a muti-Au carrier and low grade refractory gold ore

    Science.gov (United States)

    Li, W. J.; Song, Y. S.; Chen, Y.; Cai, L. L.; Zhou, G. Y.

    2017-09-01

    Detailed mineralogy and beneficiation and leaching study of a muti-Au carrier, low grade refractory gold ore from a beneficiation plant in Henan Province, China, was investigated. Mineral liberation analysis, scanning electron microscopy, element phase analysis and etc. by a mineral liberation analyser were used for mineralogical characterization study of this ore. The present work describes an experimental study on the effect of traditional parameters (such as grinding fineness and reagent regimes), middling processing method and flowsheet construction on the total recovery and the assay of the floatation concentrate. Two-step floatation and part of middling combined to the floatation tailing for gold leaching process resulted in high gold grade (g.t-1) and gold recovery (%) for this refractory gold ore. This process opens the possibilities of maximizing Au grade and recoveries in a muti-Au carrier and low grade refractory gold ore where low recoveries are common.

  17. Continued Multicolumns Bioleaching for Low Grade Uranium Ore at a Certain Uranium Deposit

    OpenAIRE

    Gongxin Chen; Zhanxue Sun; Yajie Liu

    2016-01-01

    Bioleaching has lots of advantages compared with traditional heap leaching. In industry, bioleaching of uranium is still facing many problems such as site space, high cost of production, and limited industrial facilities. In this paper, a continued column bioleaching system has been established for leaching a certain uranium ore which contains high fluoride. The analysis of chemical composition of ore shows that the grade of uranium is 0.208%, which is lower than that of other deposits. Howev...

  18. High-grade iron ore at Windarling, Yilgarn Craton: a product of syn-orogenic deformation, hypogene hydrothermal alteration and supergene modification in an Archean BIF-basalt lithostratigraphy

    Science.gov (United States)

    Angerer, Thomas; Hagemann, Steffen G.; Danyushevsky, Leonid

    2013-08-01

    Banded iron formation (BIF)-hosted iron ore deposits in the Windarling Range are located in the lower greenstone succession of the Marda-Diemals greenstone belt, Southern Cross domain, Yilgarn Craton and constitute a total hematite-martite-goethite ore resource of minimum 52 Mt at 60 wt.% Fe (0.07 P). Banded iron formation is interlayered with high-Mg basalts at Windarling and precipitated during episodes of volcanic quiescence. Trace element content and the rare earth element (REE) ratios Y/Ho (42 to 45), Sm/Yb (1.5), together with positive La and Gd anomalies in `least-altered' hematite-magnetite-metachert-BIF indicate the precipitation from Archean seawater that was fertilised by hydrothermal vent fluids with a basaltic HREE-Y signature. Hypogene iron ore in sub-greenschist facies metamorphosed BIF formed during three distinct stages: ore stage 1 was a syn- to post-metamorphic, syn-D1, Fe-Ca-Mg-Ni-Co-P-REE metasomatism that produced local Ni-REE-rich Fe-dolomite-magnetite alteration in BIF. Hydrothermal alteration was induced by hot fluid flow controlled by brittle-ductile reactivation of BIF-basalt margins and crosscutting D1 faults. The Ni-Co-rich content of dolomite and a shift in REE ratios in carbonate-altered BIF towards Archean mafic rock signature (Y/Ho to 31 to 40, Sm/Yb to 1 to 2 and Gd/Gd* to 1.2 to 1.4) suggest that high-Mg basalts in the Windarling Range were the primary source of introduced metals. During ore stage 2, a syn-deformational and likely acidic and oxidised fluid flow along BIF-basalt margins and within D1 faults leached carbonate and precipitated lepidoblastic and anhedral/granoblastic hematite. High-grade magnetite-hematite ore is formed during this stage. Ore stage 3 hydrothermal specular hematite (spcH)-Fe-dolomite-quartz alteration was controlled by a late-orogenic, brittle, compressional/transpressional stage (D4; the regional-scale shear-zone-related D3 is not preserved in Windarling). This minor event remobilised iron oxides

  19. X-ray radiometric separation of low-grade tin ores

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

    1984-10-01

    The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

  20. X-ray radiometric separation of low-grade tin ores

    International Nuclear Information System (INIS)

    Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

    1984-01-01

    The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

  1. Acid-base properties and surface complexation modeling of phosphate anion adsorption by wasted low grade iron ore with high phosphorus.

    Science.gov (United States)

    Yuan, Xiaoli; Bai, Chenguang; Xia, Wentang; An, Juan

    2014-08-15

    The adsorption phenomena and specific reaction processes of phosphate onto wasted low grade iron ore with high phosphorus (WLGIOWHP) were studied in this work. Zeta potential and Fourier transform infrared spectroscopy (FTIR) analyses were used to elucidate the interaction mechanism between WLGIOWHP and aqueous solution. The results implied that the main adsorption mechanism was the replacement of surface hydroxyl groups by phosphate via the formation of inner-sphere complex. The adsorption process was characterized by chemical adsorption onto WLGIOWHP. The non-electrostatic model (NEM) was used to simulate the surface adsorption of phosphate onto WLGIOWHP. The total surface site density and protonation constants for NEM (N(T)=1.6×10(-4) mol/g, K(a1)=2.2×10(-4), K(a2)=6.82×10(-9)) were obtained by non-linear data fitting of acid-base titrations. In addition, the NEM was used to establish the surface adsorption complexation modeling of phosphate onto WLGIOWHP. The model successfully predicted the adsorption of phosphate onto WLGIOWHP from municipal wastewater. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The impact of new technology on the economics of uranium production from low-grade ores

    International Nuclear Information System (INIS)

    Simonsen, H.A.; Boydell, D.W.; James, H.E.

    1981-01-01

    The subject is discussed under the following headings: influence of a depressed market on uranium supply from low-grade ores; potential areas for a reduction in uranium ore processing costs; in-situ leaching (solution mining; heap leaching; resin-in-pulp; solvent-in-pulp; belt filtration; continuous ion exchange; solvent extraction); preconcentration (upgrading of coarse rock; upgrading in the mill; wet high-intensity magnetic separation; flotation); summary and conclusions. (U.K.)

  3. A discussion on several problems in determination of uranium ore grade criteria

    International Nuclear Information System (INIS)

    Zhu Zhixiang.

    1991-01-01

    The course of determination of uranium ore grade criteria in China is briefly introduced. The cut-off grade minimum industrial grade and allowable minimum average grade uranium ore bodies used in China are reviewed. The meanings and role of various grade criteria and their economic basis for determination in uranium exploration, mining and sorting are discussed and the author's ideas are given

  4. Underground bioleaching: extracting from low-grade ore

    International Nuclear Information System (INIS)

    McCready, R.G.L.

    1986-01-01

    In 1984, Denison Mines began a research and demonstration project on the engineering aspects of bacterial leaching of low-grade uranium ore at Elliot Lake. The leaching solution was acidic mine water enriched in bacterial nutrients and innoculated with Thiobacillus ferrooxidans. Leaching of one stope was found to be impeded by fungi of the genus penicillium. Although fungal growth on leaching stopes must be prevented, research is proceeding on the potential use of the fungi to concentrate uranium from bioleaching solutions

  5. Preconcentration of low-grade uranium ores with environmentally acceptable tailings, part I

    International Nuclear Information System (INIS)

    Raicevic, D.; Raicevic, M.; McCarthy, D.R.

    1979-08-01

    The low-grade ore sample used for this investigation originated from Agnew Lake Mines Limited, Espanola, Ontario. It contained about 1% pyrite and 0.057% uranium, mainly as uranothorite with a small amount of brannerite. Both of these minerals occur in the quartz-sericite matrix of a conglomerate. A preconcentration process has been developed to give a high uranium recovery, reject pyrite, radium and thorium from the ore and produce environmentally acceptable tailings. This process applies flotation in combination with high intensity magnetic separation and gravity concentration

  6. Low grade uranium ores as potential sources of raw material

    International Nuclear Information System (INIS)

    Venzlaff, H.

    1976-01-01

    Reports on the uranium requirement and the uranium reserves show that, even if the demand were to be stretched out slightly, the rate of new discoveries of uranium would have to be doubled or even tripled within a few years in order to ensure supply. Despite some spectacular discoveries of large scale deposits in Australia it must be said that only very few truly new uranium provinces have been discovered over the past twenty years. In this situation more attention is now being devoted to low grade uranium depositis, to findings whose concentration does not exceed 1,000 ppm. These deposits contain quantities of uranium many times larger than the deposits that can now be mined at prices up to 30/lb of U 3 O 8 . Even now low grade uranium ore is being mined as a byproduct, with the actual valuable mineral producing most of the income from mining activities. However, if one strikes a balance in this situation, one finds that only part of the requirement can be met in this way. Hence, all possibilities must be exhausted to mine uranium as a byproduct, new techniques of uranium production from low grade ores must be developed, and also conventional prospection must be intensified, if the continuity of supply of the nuclear power stations in the eighties and nineties is to be guaranteed. (orig.) [de

  7. Grade control and the determination of ore reserves at a low-grade uranium mine

    International Nuclear Information System (INIS)

    Reid, J.A.F.; Robertson, B.

    1982-01-01

    In 1966 an intensive exploration programme was conducted by Rio Tinto South Africa Ltd, involving airborne and ground radiometric surveys, percussion and diamond drilling, and pilot-plant tests. This investigation established the presence of a large deposit of low-grade uranium that could be mined on a large scale by open-pitting. Soon after production started in June 1974, it was realized that the original presentation of the ore reserves did not give a true reflection of the orebody. A comparison between the estimates and the ore mined from reserve blocks over the period 1975 to 1977 showed that the reserve grades were over-optimistic. In 1977 Rio Tinto Zinc Consultants were commissioned to re-evaluate the ore reserves from exploration diamond-drill data with the help of The Centre de Geostatistique at Fontainebleau, France. A new global reserve using disjunctive kriging techniques was developed, and is now the long-term reserve used for planning purposes at the Roessing Mine. For short-term planning, ore-reserve data are replaced by information from an intermediate drilling programme and blast-hole assays if these are available. A computerized short-term planning system has been established that reconciles the ore mined against the reserve blocks, as well as a system by which composited blast-hole assays are analysed for grade-control purposes. Owing to the complexity of the orebody, additional monitoring is achieved by the scanning of each truckload of ore with a group of scintillation crystal heads that evaluate the material mined

  8. Recovery of copper and precious metals from chalcopyrite low grade ores - choice between flotation or microorganisms leaching

    OpenAIRE

    Krstev, Boris; Golomeov, Blagoj; Konzulov, Gerasim; Gocev, Zivko

    1998-01-01

    The conventional flotation technologies cannot provide fair results when to applied to very low grade ores or to "refractory" ores. This class include intimate and nonuniform mineral associations, with partialy oxidized minerals and high secondary mineral content and also high soluble salt content, pre-activated minerals because of the excessive permeability of the deposit and of the intense circulation of waters with heavy metal ions etc. Bacterial oxidation as a means to the recovery of met...

  9. Considerations on the utilisation of the extraction residue from U, Th production from low grade ores

    International Nuclear Information System (INIS)

    Huwyler, S.

    1979-11-01

    A literature review about processes for the winning of metals from the extraction residue of low grade U, Th-ores has been made. Among the metals recoverable aluminium is being considered as the most interesting one. The aluminium extraction processes discussed here include high temperature chlorination, the BAYER-process, acid and SO 3 digestion processes, winning of an AlSiFe-alloy by electrometallurgy. The merits of the different processes are compared. (Auth.)

  10. Technologies for processing low-grade uranium ores and their relevance to the Indian situation

    International Nuclear Information System (INIS)

    Murthy, T.K.S.

    1991-01-01

    The technology for uranium ore processing is well established. Various estimates have shown that on a global basis uranium resources are adequate to meet the forseeable demand. The Indian resources are estimated to be about 60,000 t U. The grade of the ores is low and the individual deposits are small. The nature of the deposits, precarious resources position and relatively small capacity of the mines do not permit the country to take advantage of large throughputs in the mill to achieve substantial cost reduction. However by resorting to as high a scale of milling as the mines would permit, by reducing the loss of solubilised uranium after leaching and by undertaking production of nuclear grade final product at the mill site, significant though not a major, economic benefit can be derived. (author). 2 figs., 3 tabs

  11. Mutualism between autotrophic and heterophic bacteria in leaching of low grade ores

    International Nuclear Information System (INIS)

    Khalid, Z.M.; Naeveke, R.

    1991-01-01

    During solubilization processes of low grade sulphidic ores, the auto trophic bacteria oxidize reduced sulphur compounds and ferrous iron to sulphates and ferric iron respectively. The ore leaching bio topes are not only colonized by auto trophic bacteria (Thiobacillus spp., Leptospirillum ferro oxidans and sulfolobus sp.) but the heterotrophic microorganisms, including bacteria and fungi of various species are also found in these habitats. The autotrophs, in addition to energy metabolism, also produce organic compounds which in excess amount inhibit their growth. Through the utilization of such compounds and also through the production of carbon dioxide and ammonia, these heterotorphs can help bio leaching processes. Effect of one of the heterotrophs; methylobacterium sp., a nitrogen scavenger, found in as association with the thio bacilli in one of the leaching bio tope in Germany was studied in leaching of a carbonate bearing complex (containing copper, iron, zinc and lead) sulphidic ore, in shake flask studies. T. ferro oxidans (Strain F-40) reported to be non nitrogen fixer and strain F-41, a nitrogen fixing thiobacillus were studied for leachability behaviour alone and in combination with T. thio oxidans (lacking nitrogen fixing ability) using media with and without added ammonium nitrogen. In addition the effect of methylobacterium sp. (alt-25) was also tested with the afore mentioned combinations. Nitrogen fixation by T. ferro oxidans did not suffice the nitrogen requirement and the leaching system in laboratory needed addition of nitrogen. The heterotrophic nitrogen scavenger also did not have a positive influence in nitrogen limited system. In case where ammonium nitrogen was also provided in the media, this heterotroph had a negative in own growth and leaving lesser amount available for thio bacilli. This high amount of acid is a limiting factor in bio leaching of high carbonate uranium ores. Uranium ore ecosystems have also been found to contain

  12. Status Report from the United States of America [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R H [United States Atomic Energy Commission, Washington, D.C. (United States)

    1967-06-15

    The US uranium production rate has been dropping gradually from a high of 17 760 tons in fiscal year 1961 to a level of about 10 400 tons in fiscal year 1966. As of 1 January 1966, there were 17 uranium mills in operation in the USA compared with a maximum of 26 during 1961, the peak production year. Uranium procurement contracts between the USAEC and companies operating 11 mills have been extended through calendar year 1970. The USAEC contracts for the other six mills are scheduled to expire 31 December 1966. Some of these mills, however, have substantial private orders for production of uranium for nuclear power plants and will continue to operate after completion of deliveries under USAEC contracts. No new uranium mills have been brought into production since 1962. Under these circumstances the emphasis in process development activities in recent years has tended toward improvements that could be incorporated within the general framework of the existing plants. Some major flowsheet changes have been made, however. For example, two of the ore-processing plants have shifted from acid leaching to sodium carbonate leach in order to provide the flexibility to process an increasing proportion of ores of high limestone content in the tributary areas. Several mills employing ion exchange as the primary step for recovery of uranium from solution have added an 'Eluex' solvent extraction step on the ion exchange eluate. This process not only results in a highgrade final product, but also eliminates several metallurgical problems formerly caused by the chloride and nitrate eluants. Such changes together with numerous minor improvements have gradually reduced production cost and increased recoveries. The domestic uranium milling companies have generally had reserves of normal-grade ores well in excess of the amounts required to fulfil the requirements for their contracts with the USAEC. Therefore, there has been little incentive to undertake the processing of lower grade

  13. Using Cut-off grade isograms to delineate ore body and calculate parameter

    International Nuclear Information System (INIS)

    Yu Yongfeng; Zhu Xiaobing; Deng Yonghui

    2014-01-01

    Taking a uranium mine for an example, using cut-off grade isograms to achieve automatic delineation of ore body and calculation of parameters are explored. With center line of catalog sampling as baseline, the number of sampling and length of sampling constructing rectangular grid and grade as elevation value, isograms of cut-off grade were drawn, thus achieving the delineation of the ore body. Then, the other parameters of the ore body can be calculated. Compared with the traditional hand drawing method, the work efficiency was greatly improved, and the material inquiry was more convenient. (authors)

  14. The measurement and inclusion of a stochastic ore-grade uncertainty in mine valuations using PDEs

    OpenAIRE

    Evatt, G. W.; Johnson, P. V.; Duck, P. W.; Howell, S. D.

    2010-01-01

    Mining companies world-wide are faced with the problem of how to accurately value and plan extraction projects subject to uncertainty in both future price and ore grade. Whilst the methodology of modelling price uncertainty is reasonably well understood, modelling ore-grade uncertainty is a much harder problem to formulate, and when attempts have been made the solutions have taken unfeasibly long times to compute. This paper provides a new partial differential equations approach to the proble...

  15. Continued Multicolumns Bioleaching for Low Grade Uranium Ore at a Certain Uranium Deposit

    Directory of Open Access Journals (Sweden)

    Gongxin Chen

    2016-01-01

    Full Text Available Bioleaching has lots of advantages compared with traditional heap leaching. In industry, bioleaching of uranium is still facing many problems such as site space, high cost of production, and limited industrial facilities. In this paper, a continued column bioleaching system has been established for leaching a certain uranium ore which contains high fluoride. The analysis of chemical composition of ore shows that the grade of uranium is 0.208%, which is lower than that of other deposits. However, the fluoride content (1.8% of weight is greater than that of other deposits. This can be toxic for bacteria growth in bioleaching progress. In our continued multicolumns bioleaching experiment, the uranium recovery (89.5% of 4th column is greater than those of other columns in 120 days, as well as the acid consumption (33.6 g/kg. These results indicate that continued multicolumns bioleaching technology is suitable for leaching this type of ore. The uranium concentration of PLS can be effectively improved, where uranium recovery can be enhanced by the iron exchange system. Furthermore, this continued multicolumns bioleaching system can effectively utilize the remaining acid of PLS, which can reduce the sulfuric acid consumption. The cost of production of uranium can be reduced and this benefits the environment too.

  16. Advantage of uranium contained in low grade dolomite ore

    International Nuclear Information System (INIS)

    Carneiro, A.L.M.

    1988-01-01

    The purpose of this work is to investigate a technological route to recover uranium from a lean mineral ore. The experimental work includes studies concerning calcination, carbonate leaching, settling, filtration and resin-ion-exchange. Experimental data confirm the technological feasibility of the proposed process and two different preliminary flowsheets of a pilot plant were suggested. (author) [pt

  17. Status Report from the United Kingdom [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    North, A A [Warren Spring Laboratory, Stevenage, Herts. (United Kingdom)

    1967-06-15

    The invitation to present this status report could have been taken literally as a request for information on experience gained in the actual processing of low-grade uranium ores in the United Kingdom, in which case there would have been very little to report; however, the invitation naturally was considered to be a request for a report on the experience gained by the United Kingdom of the processing of uranium ores. Lowgrade uranium ores are not treated in the United Kingdom simply because the country does not possess any known significant deposits of uranium ore. It is of interest to record the fact that during the nineteenth century mesothermal vein deposits associated with Hercynian granite were worked at South Terras, Cornwall, and ore that contained approximately 100 tons of uranium oxide was exported to Germany. Now only some 20 tons of contained uranium oxide remain at South Terras; also in Cornwall there is a small number of other vein deposits that each hold about five tons of uranium. Small lodes of uranium ore have been located in the southern uplands of Scotland; in North Wales lower palaeozoic black shales have only as much as 50 to 80 parts per million of uranium oxide, and a slightly lower grade carbonaceous shale is found near the base of the millstone grit that occurs in the north of England. Thus the experience gained by the United Kingdom has been of the treatment of uranium ores that occur abroad.

  18. High-rate behaviour of iron ore pellet

    Science.gov (United States)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  19. Status report from India [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Fareeduddin, S [Atomic Energy Establishment, Trombay, Bombay (India)

    1967-06-15

    The Energy Survey Committee of India, in its report to the Government, has estimated that the energy requirements in the year 1985/86 would be 290X10{sup 9} kWh, i. e. eight times the present requirement, and in the year 2000 it would be 820X10{sup 9} kWh, which is about 22 times the present requirement. The hydropotential that can be developed during the next 20 years is estimated to be of the order of 150X10{sup 9} kWh and hence the difference of about 140X10{sup 9} kWh will have to be obtained from either fossil or nuclear fuel. This would mean installating a generation capacity of about 26 000 MW in the next 20 years. To conserve the limited fossil fuel reserves, it has been estimated that about 70% of this capacity, i. e. about 18 000 MW, should form the nuclear component. This will be about 25% of the total energy requirements by 1985/86. The uranium requirements to meet this growth will be about 10 000 tonnes by 1985/86 which, from the point of view of our resources, is a substantial quantity. The most important uranium deposits are located in South Bihar in the Singhbhum Thrust belt, which is well known for its copper, apatite magnetite and kyanite deposits. On the basis of their uranium contents, these ores can be classified into two broad categories - one with low copper and high uranium contents and the other with high copper and low uranium contents. Another source of uranium in India is monazite. Some particulars about these deposits are given. Facilities for the recovery of byproduct uranium from monazite already exist in the country. But its production from this source, conditioned as it is by the limited demand for thorium, cannot be very large. Both the categories of the ores from the Singhbhum belt can be considered as low grade. Uranium from the ores in category (B) can be recovered, in the present state of knowledge, only as a byproduct of the copper industry. In the case of ores in the category (A), attempts have been made to recover uranium

  20. Characterization and Beneficiation Studies of a Low Grade Bauxite Ore

    Science.gov (United States)

    Rao, D. S.; Das, B.

    2014-10-01

    A low grade bauxite sample of central India was thoroughly characterized with the help of stereomicroscope, reflected light microscope and electron microscope using QEMSCAN. A few hand picked samples were collected from different places of the mine and were subjected to geochemical characterization studies. The geochemical studies indicated that most of the samples contain high silica and low alumina, except a few which are high grade. Mineralogically the samples consist of bauxite (gibbsite and boehmite), ferruginous mineral phases (goethite and hematite), clay and silicate (quartz), and titanium bearing minerals like rutile and ilmenite. Majority of the gibbsite, boehmite and gibbsitic oolites contain clay, quartz and iron and titanium mineral phases within the sample as inclusions. The sample on an average contains 39.1 % Al2O3 and 12.3 % SiO2, and 20.08 % of Fe2O3. Beneficiation techniques like size classification, sorting, scrubbing, hydrocyclone and magnetic separation were employed to reduce the silica content suitable for Bayer process. The studies indicated that, 50 % by weight with 41 % Al2O3 containing less than 5 % SiO2 could be achieved. The finer sized sample after physical beneficiation still contains high silica due to complex mineralogical associations.

  1. Uranium R and D directed to low-grade ores

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The treatment of depleted uranium ores by in-situ leaching and by counterflow ion exchange in the USA is described. In-situ leaching is mainly suitable for sandstone deposits. The research was originally focused on leaching with an acid and with carbonates. Phosphoric acid appears to be a promising leaching agent. The equipment for continuous ion exchange may be used for sludge processing but the application depends on the type of equipment and mineralogy of processed ores. The method is advantageous for lower capital costs and for smooth operation. Ion exchange is also used for uranium extraction from mine waters in the USA as well as in Canada. For example, in Grants, New Mexico, a yield exceeding 90% was reached in mine waters only containing 5 to 7 ppm U 3 O 8 . In the future, the treatment of ores with a low uranium content will require more selective extraction methods in view of the more stringent technical conditions of uranium concentrate processing. (J.P.)

  2. Microcontroller based, ore grade measuring portable instruments for uranium mining industry

    International Nuclear Information System (INIS)

    Dheeraj Reddy, J.; Narender Reddy, J.

    2004-01-01

    Ore Face Scanning and Bore Hole Logging are important essential activities which are required to be carried out in any Uranium mining industry. Microcontroller based, portable instruments with built-in powerful embedded code for data acquisition (of Radiation counts) and Ore Grade calculations will become a handy measuring tool for miners. Nucleonix Systems has recently developed and made these two portable instruments available to UCIL, which are under use at Jaduguda and Narvapahar mines. Some of the important features of these systems are compact, light weight, portable, hand held, battery powered. Modes of Data Acquisition: CPS, CPM and ORE GRADE. Detector: Sensitive GM Tube. Choice of Adj. TC (Time Constant) in 'ORE GRADE', acquisition mode. Built-in automatic BG (Background) recording and subtraction provided to indicate net CPS, CPM or ore GRADE in PPM. Can store 1000 readings at users choice. Built-in RS232 serial port facilitates data downloading into PC. This paper focuses on design concepts and technical details for the above two products. (author)

  3. Titrimetric determination of uranium in low-grade ores by the ferrous ion-phosphoric acid reduction method

    International Nuclear Information System (INIS)

    Hitchen, A.; Zechanowitsch, G.

    1980-01-01

    The modification and extension of the U.S.A.E.C. ferrous ion-phosphoric acid reduction method for the determination of uranium in high-grade or relatively pure material to a method for the determination of uranium with a high accuracy and precision, in ores containing 0.004 to 7% U is described. It is simple, rapid and requires no prior separations from elements that, in other methods, frequently interfere. For sample materials having very high concentrations of interfering elements, a prior concentration step using extraction with tri-n-octylphosphine oxide is described, but it is shown that, for most low-grade ores, this step is unnecessary. (author)

  4. An instrument for rapid delineation of grade boundaries in selective mining of uranium ore

    International Nuclear Information System (INIS)

    Clark, G.J.; Dickson, B.L.; Meakins, R.L.; Kenny, D.; Talaska, A.

    1982-01-01

    A vehicle-mounted radiation detector interfaced to a microprocessor called PRAM (programmable radioactive analyser mobile) has been developed to provide grade control for selective mining of a soft rock uranium ore. The grade of ore over which the vehicle passes is determined and indicated by several coloured lights to a pegman who walks behind the vehicle. Coloured pegs are then laid out to mark the uranium grade ranges on the floor of the mine pit. Comparison between grade ranges determined by the PRAM and by prior drilling and downhole logging at the Yeelirrie deposit, Western Australia indicate good agreement. Use of the PRAM decreases the cost, manpower and time required to grade extensive areas of a mine pit floor

  5. Bioleaching of low-grade uranium ore using Acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Pal, S.; Das, T.; Sukla, L.B.; Roy Chaudhury, G.; Pradhan, D.

    2010-01-01

    Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda. The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect. (author)

  6. Spectrophotometric Determination of Thorium in Low Grade Minerals and Ores

    Energy Technology Data Exchange (ETDEWEB)

    Arnfelt, A L; Edmundsson, I

    1960-08-15

    The following method is intended for the determination of microgram quantities of thorium in samples of minerals and ores. The mineral sample is decomposed by repeated sintering with sodium peroxide. After digestion with water thorium peroxide hydrate is recovered by centrifugation and dissolved in hydrochloric acid. Thorium is determined spectrophotometrically with naphtarson after its separation from metals forming chloro complexes which are adsorbed on a strongly basic anion exchange resin. Interferences from a few different ions have been studied. The time required for the analysis of one sample is about 4 hours, when analysing 12 samples simultaneously

  7. Spectrophotometric Determination of Thorium in Low Grade Minerals and Ores

    International Nuclear Information System (INIS)

    Arnfelt, A.L.; Edmundsson, I.

    1960-08-01

    The following method is intended for the determination of microgram quantities of thorium in samples of minerals and ores. The mineral sample is decomposed by repeated sintering with sodium peroxide. After digestion with water thorium peroxide hydrate is recovered by centrifugation and dissolved in hydrochloric acid. Thorium is determined spectrophotometrically with naphtarson after its separation from metals forming chloro complexes which are adsorbed on a strongly basic anion exchange resin. Interferences from a few different ions have been studied. The time required for the analysis of one sample is about 4 hours, when analysing 12 samples simultaneously

  8. Status Report from Yugoslavia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Bunji, B [Institute for Technology of Nuclear and Other Raw Materials, Belgrade, Yugoslavia (Serbia)

    1967-06-15

    barren solution has resulted in important savings on reagent. The overall economy compared under local conditions with ion-exchange or solvent extraction is in favour of the reduction process. Some research work on heap leaching and leaching in situ is included in our activities. In connection with the conditions at Kalna it was possible to carry out large-scale heap leaching and leaching in situ. The former was carried out on waste rocks with a uranium content below the cut-off grade. To avoid solution losses, the surface area from the heap pile is covered with thin plastic sheets. Good drainage from the bottom is obtained by using perforated 10-in. asbestos-concrete pipes. The technique of construction of the heap pile is as usual, and mostly depends on local conditions. The heap leach pile is about 12 m high. The solution retention time is about 8 days. The barren solution from the reduction plant or mine water with a uranium content in the range of 2 to 6 g/m{sup 3} is used for the heap leaching. The pregnant solution is returned into the processing plant. Because the heap leach pile obtained is practically without any charge, the operating and the construction costs of the heap pile need only be in balance with the value of the recovered uranium. Investigation of bacterial leaching has shown some influence on the leaching rate. The bacteria belonging to the Thiobacillus-Ferrobacillus group were obtained from mine water, selected and cultivated. It seems that the concentration of bacteria has some influence on the extraction time and percentage of extracted uranium, and it can be said that the application of bacteria in heap leaching and leaching in situ will in the future be one of the most effective methods of uranium extraction from ore that is below cut-off grade. (author)

  9. Heap bioleaching of uranium from low-grade granite-type ore by mixed acidophilic microbes

    International Nuclear Information System (INIS)

    Xuegang Wang; Zhongkui Zhou

    2017-01-01

    We evaluated uranium bioleaching from low-grade, granite-type uranium ore using mixed acidophilic microbes from uranium mine leachate. A 4854-ton plant-scale heap bioleaching process achieved sustained leaching with a uranium leaching efficiency of 88.3% using a pH of 1.0-2.0 and an Fe"3"+ dosage of 3.0-5.5 g/L. Acid consumption amounted to 25.8 g H_2SO_4 kg"-"1 ore. Uranium bioleaching follows a diffusion-controlled kinetic model with a correlation coefficient of 0.9136. Almost all uranium was dissolved in aqueous solution, except those encapsulated in quartz particles. Therefore, heap bioleaching by mixed acidophilic microbes enables efficient, economical, large-scale recovery of uranium from low-grade ores. (author)

  10. A case study of shrinkage-in place leaching of low grade uranium ore deposit

    International Nuclear Information System (INIS)

    Ding Dexin; Zhou Guohe

    1998-09-01

    A case study of shrinkage-in place leaching of low grade uranium ore deposit is dealt with. A test block was selected, and the shrinkage mining method was employed to construct the in place heap for leaching. Blast parameters and operations were carefully tried in order to make sure that the fragment size composition was adequate for leaching. A leaching system was planned and the corresponding leaching parameters were tried, too. The results show that the shrinkage method and the parameters for blasting and leaching are all adequate for the in-situ leaching of the blasted ore. This shrinkage-in place leaching system combines the mining and metallurgy processes into one and produces a lot of profits and could be applicable to many low grade uranium ore deposits which are so hard and compact that they have to be fragmented before being leached

  11. The application of CPLD in online nuclear detection meter of ore grade

    International Nuclear Information System (INIS)

    Yin Yiqiang; Yin Deyou; Gong Yalin; Shang Qingmin; Xiao Xiandong; Zhou Hongjun; Yu Haiming

    2010-01-01

    The pulse height analysis circuit for nuclear pulse signals is an important function cell of online nuclear detection meter, requiring high speed and credible logic circuit to eliminate the signal pileup rejection, overload detection, instrumentation measurement dead time on the adverse effects of spectrum. In order to improve the performance of nuclear detection meter, some function circuits are used, such as live time offset, overload detection and pileup rejection. The CPLD and multi single-channel spectrum measurement method used in ore grade nuclear instrumentation, eliminating the pileup, overload signal and accurately compensated the measurement of dead time, thus the circuit functions above are carried out credibly and the meter detection accuracy is improved drastically. (authors)

  12. Status Report from Czechoslovakia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Civin, V; Belsky, M [Research and Development Laboratory No.3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

    1967-06-15

    The present paper deals with the fundamental problems and the main routes followed in processing low-grade uranium ores in CSSR. In this connection it may be useful to discuss the definition of low-grade ore. In our country this term is applied to uraniferous material with a very low content of uranium (of the order of 0.01%) whose treatment causes no particular difficulty. However, the same term is also used to designate those materials whose processibility lies on the verge of economic profitability. In our view, this classification, of an ore using two independent criteria (i.e. uranium content and processing economy) is useful from the standpoint of technology. The treatment of both such ore types is as a rule carried out by specific technological processes. Consequently, low-grade uranium ores can be divided into two groups: (1) Ores with a low uranium content. To this category belong in our country uraniferous materials which originate as a by-product of technological processes used in processing other materials. This is primarily gangue and tailings of various physical or physico-chemical pretreatment operations to which the ore is subjected at the mining site. Mention should be made in this connection of mine waters, which represent a useful complementary source of uranium despite their low uranium content (of the order of milligrams per litre). (2) Ores whose economical treatment is problematic. To this category belong deposits of conventional ore types with a uranium content on the limit of profitable treatment. Also, those deposits containing atypical materials possessing such properties which impair the economy of their treatment. This includes ores with a considerable amount of components which are difficult to separate and which at the same time consume the leaching agents. Finally, it covers uranium-bearing materials in refractory forms which are difficult to dissolve and also some special materials, such as lignites, uranium-bearing shales, loams

  13. Extraction of a Low Grade Zinc Ore using Gravity and Froth Flotation ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Extraction of low grade zinc ore found in Gumau- Toro town was carried out using gravity and froth flotation methods. .... And to determine the best separation ..... Wet De, K; Singleton, J.D (2008) Development of a. Viable Process ...

  14. A new type on line fast analysis instrument of uranium ore grade

    International Nuclear Information System (INIS)

    Guo Maojin.

    1992-01-01

    The instrument is used to analyse the average grade of uranium ore on the belt. Its average analysis speed is about 300 t/h. The physical mechanism of measurement, characteristics, principle of operation and applications in several years are described. The CMOS LSI IC are adopted. The stability, reliability and anti-interference ability are very good

  15. Microbial leaching of low grade sandstone uranium ores: column leaching studies

    International Nuclear Information System (INIS)

    Bhatti, T.M.; Malik, K.A.; Khalid, A.M.

    1991-01-01

    Microbial leaching studies on a low-grade sandstone uranium ore from Baghalchur Ore Deposits, D. G. Khan, Pakistan, containing 0.027 % U/sub 3/O/sub 8/ for extraction of uranium, were conducted in columns. Baghalchur sandstone uranium ore which is alkaline in nature, contained 5.0% calcite [CaCo/sub 3/], 2-3 % Fe/sub 2/O/sub 3/ and pyrite [FeS/sub 2/] less than 0.1 %. The ore amended with sulfur and/or sulfur slag as external energy source was found to leach with indigenous microflora mostly belonging to the genus Thiobacillus which are present in the uranium mine water. Column leaching studies revealed that when the ore was amended with elemental sulfur and irrigated with mine water (pH 3.5) 53 % U/sub 3/O/sub 8/ could be solubilized from it. However, when the natural mine water was used as such (pH 7.4) the solubilization of uranium was decreased to 41 % U/sub 3/O/sub 8/ in 90 days under similar conditions of percolation rate and temperature. The addition of (NH/sub 4/)/sub 2/SO/sub 4/ (3.0 g/L) in mine water was found to enhance the uranium leaching to 70 % U/sub 3/O/sub 8/ from the columns containing ore amended with sulfur slag. (author)

  16. Multistage dilute acid leaching of a medium grade iron ore to super-concentrate

    Directory of Open Access Journals (Sweden)

    Adeleke A.A.

    2014-01-01

    Full Text Available The phosphorous laden Koton Karfe iron ore is a medium grade iron ore deposit in Nigeria that can be upgraded as a super-concentrate for use at the Aladja Steel Midrex plant. The 75 μm size sample fraction of the ore was preconcentrated with shaking table and leached in the oven at atmospheric pressure with dilute hydrochloric acid in single and multistage leaching sequences of H2O-HCl-H2O and HCl-H2O-H2O. The as-received, as-tabled and asleached samples were then subjected to X-ray fluorescence and microscopic analyses. The results obtained showed that the H2O-HCl-H2O route produced a higher grade concentrate that assayed 68.54% Fe indicating about 58% upgrade in iron content; while the phosphorus and sulphur contents were reduced by about 77 and 99.6% respectively. In addition, the silicon, manganese, and titanium contents were drastically reduced, while potassium was completely eliminated. The upgrade of iron content in the ore to 68.54% and the drastic reduction in phosphorous and sulphur contents has thus rendered the Koton Karfe iron ore suitable for use as a super concentrate for the Aladja steel plant direct reduction iron making process.

  17. A REAL-TIME COAL CONTENT/ORE GRADE (C2OC) SENSOR

    Energy Technology Data Exchange (ETDEWEB)

    Rand Swanson

    2005-04-01

    This is the final report of a three year DOE funded project titled ''A real-time coal content/ore grade (C{sub 2}OG) sensor''. The sensor, which is based on hyperspectral imaging technology, was designed to give a machine vision assay of ore or coal. Sensors were designed and built at Resonon, Inc., and then deployed at the Stillwater Mining Company core room in southcentral Montana for analyzing platinum/palladium ore and at the Montana Tech Spectroscopy Lab for analyzing coal and other materials. The Stillwater sensor imaged 91' of core and analyzed this data for surface sulfides which are considered to be pathfinder minerals for platinum/palladium at this mine. Our results indicate that the sensor could deliver a relative ore grade provided tool markings and iron oxidation were kept to a minimum. Coal, talc, and titanium sponge samples were also imaged and analyzed for content and grade with promising results. This research has led directly to a DOE SBIR Phase II award for Resonon to develop a down-hole imaging spectrometer based on the same imaging technology used in the Stillwater core room C{sub 2}OG sensor. The Stillwater Mining Company has estimated that this type of imaging system could lead to a 10% reduction in waste rock from their mine and provide a $650,000 benefit per year. The proposed system may also lead to an additional 10% of ore tonnage, which would provide a total economic benefit of more than $3.1 million per year. If this benefit could be realized on other metal ores for which the proposed technology is suitable, the possible economic benefits to U.S. mines is over $70 million per year. In addition to these currently lost economic benefits, there are also major energy losses from mining waste rock and environmental impacts from mining, processing, and disposing of waste rock.

  18. Chlorination separation of uranium, thorium, and radium from low-grade ores

    International Nuclear Information System (INIS)

    Sastri, V.S.; Perumareddi, J.R.

    1995-01-01

    Low-temperature chlorination of low-grade uranium ores containing uranium in the 0.02 to 0.06% range, thorium in the 0.036 to 0.12% range, and radium in the 70 to 200 pci/g range resulted in the extraction of >90% of the constituents. The residue left after chlorination was found to be innocuous and suitable for disposal as a waste acceptable to the environment. Use of sodium chloride in the charge was useful in reducing the chlorination temperature and in the formation of nonvolatile anionic chloro complexes of the metal ions in the ore

  19. Beneficiation strategy for some low grade ores of strategic metals in India

    International Nuclear Information System (INIS)

    Krishna Rao, N.

    1997-01-01

    In developing indigenous resources of strategic metals, beneficiation strategy has a major role to play, particularly where the ores are of low tenor. Presently India imports most of its requirements of metals like tin, tungsten, molybdenum, nickel and cobalt. In all these cases important low grade resources occur in the country. Beneficiation strategy necessary for exploitation of these deposits are discussed based mainly on vast batch and semi plant scale data generated in the Ore Dressing Section of Bhabha Atomic Research Centre. Also discussed is the case of strategic metal uranium where, in certain cases pre-concentration by beneficiation has the potential to make it feasible the exploitation of otherwise difficult to process ore resources. (author)

  20. Effects of Sodium Citrate on the Ammonium Sulfate Recycled Leaching of Low-Grade Zinc Oxide Ores

    Science.gov (United States)

    Yang, Kun; Li, Shi-wei; Zhang, Li-bo; Peng, Jin-hui; Ma, Ai-yuan; Wang, Bao-bao

    2016-03-01

    The effects of sodium citrate on ammonium sulfate recycled leaching of low-grade zinc oxide ores were studied. By applying various kinds of detection and analysis techniques such as chemical composition analysis, chemical phase method, scanning electron microscopy and energy dispersive spectrum (SEM/EDS), X-ray diffraction (XRD) and Fourier-transforming infrared spectrum (FT-IR), zinc raw ore, its leaching slag and the functional mechanism of sodium citrate were investigated. Based on a comprehensive analysis, it can be concluded that in contrast to hemimorphite (Zn4Si2O7(OH)2 · H2O), amorphous smithsonite (ZnCO3) and zinc silicate (Zn2SiO4) prove to be refractory phases under ammonium sulfate leaching, while sodium citrate has a better chelating action with the refractory phases, resulting in a higher zinc leaching rate. Under conditions of [NH3]/[NH3]T molar ratio being 0.5, [NH3]T being 7.5 mol/L, [Na3C6H5O7] being 0.2 mol/L, S/L ratio being 1:5, temperature being 303 K, holding time being 1 h in each of the two stages, and stirring rate being 300 rpm, the leaching rate of zinc reached 93.4%. In this article, sulfate ammonium recycled technology also reveals its unique advantage in processing low-grade zinc oxide ores accompanied by high silicon and high alkaline gangue.

  1. Feasibility Studies for Production of Pellet Grade Concentrate from Sub Grade Iron Ore Using Multi Gravity Separator

    Science.gov (United States)

    Rao, Gottumukkala Venkateswara; Markandeya, R.; Kumar, Rajan

    2018-04-01

    An attempt has been made to utilise Sub Grade Iron Ore by producing pellet grade concentrate from Deposit 5, Bacheli Complex, Bailadila, Chhattisgarh, India. The `as received' Run of Mine (ROM) sample assayed 40.80% Fe, 40.90% SiO2. Mineralogical studies indicated that the main ore mineral is Hematite and lone gangue mineral is Quartz. Mineral liberation studies indicated that, the ore mineral Hematite and gangue mineral Quartz are getting liberated below 100 microns. The stage crushed and ground sample was subjected to concentration by using a Multi Gravity Separator (MGS). Rougher Multi Gravity Separation (MGS) experimental results were optimised to recover highest possible iron values. A concentrate of 55.80% Fe with a yield of 61.73% by weight with a recovery of 84.42% Iron values was obtained in rougher MGS concentrate. Further experiments were carried out with rougher MGS concentrate to produce a concentrate suitable for commercial grade pellet concentrate. It was proved that a concentrate assaying 66.67% Fe, 3.12% SiO2 with an yield of 45.08% by weight and with a recovery of 73.67% iron values in the concentrate.

  2. Uranium Processing Research in Australia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J R [Australian Atomic Energy Commission, Coogee, N.S.W. (Australia)

    1967-06-15

    Uranium processing research in Australia has included studies of flotation, magnetic separation, gravity separation, heavy medium separation, atmospheric leaching, multi-stage leaching, alkali leaching, solar heating of leach pulps, jigged-bed resin-in-pulp and solvent-in-pulp extraction. Brief details of the results obtained are given. In general, it can be said that gravity, magnetic and flotation methods are of limited usefulness in the treatment of Australian uranium ores. Alkali leaching seldom gives satisfactory recoveries and multi-stage leaching is expensive. Jigged-bed resin-in-pulp and packed tower solvent-in-pulp extraction systems both show promise, but plant-scale development work is required. Bacterial leaching may be useful in the case of certain low-grade ores. The main difficulties to be overcome, either singly or in combination, in the case of Australian uranium ores not currently considered economically exploitable, are the extremely finely divided state of the uranium mineral, the refractory nature of the uranium mineral and adverse effects due to the gangue minerals present. With respect to known low-grade ores, it would be possible in only a few cases to achieve satisfactory recovery of uranium at reasonable cost by standard treatment methods. (author)

  3. Preconcentration of a low-grade uranium ore yielding tailings of greatly reduced environmental concerns. Part V

    International Nuclear Information System (INIS)

    Raicevic, D.; Raicevic, M.

    1980-11-01

    The low-grade ore sample used for this investigation contained 0.057 percent uranium with uranothorite as the major uranium-bearing mineral and a small amount of brannerite, occurring in the quartz-sericite matrix of a conglomerate. The preconcentration procedures, consisting of pyrite flotation with or without flotation of radioactive minerals, followed by high intensity wet magnetic treatment of the sized flotation tailings, produced pyrite and radioactive concentrates of acceptable uranium grades ranging from 0.1 to 0.135 percent uranium. The combined concentrates comprised 37 to 49 percent of the ore by weight with the following combined recoveries: 95.6 to 97.9 percent of the uranium; 94.7 to 96.3 percent of the radium; 97.8 to 99.3 percent of the thorium over 98 percent of the pyrite. The preconcentration tailings produced comprised between 51 and 63 percent of the ore by weight and contained from: 0.0022 to 0.0037 percent U; 12 to 17 pCi/g Ra; 0.002 to 0.004 percent Th less than 0.03 percent S. Because these tailings are practically pyrite-free, they should not generate acidic conditions. Due to their low radium content, their radionuclide hazards are greatly reduced. These preconcentration tailings therefore, could be suitable for surface disposal, mine backfill, revegetation or other uses

  4. RECOVERY OF IRON FROM LOW-GRADE HEMATITE ORE USING COAL-BASED DIRECT REDUCTION FOLLOWED BY MAGNETIC SEPARATION

    Directory of Open Access Journals (Sweden)

    N. Alavifard

    2016-09-01

    Full Text Available In the present work, iron recovery from a low-grade hematite ore (containing less than 40% iron, which is not applicable in common methods of ironmaking, was studied. Non-coking coal was used as reducing agent. Reduction experiments were performed under various coal to hematite ratios and temperatures. Reduction degree was calculated using the gravimetric method. Reduced samples were subjected to magnetic separation followed by X-ray diffraction analysis. Total iron content, degree of metallization and recovery efficiency in magnetic part were determined by quantitative chemical analysis, which were obtained about 82%, 95% and 64% respectively under optimal conditions. CaO as an additive improved ore reducibility and separation efficiency. The microstructure of reduced samples and final products were analyzed by scanning electron microscopy. Final product with a high degree of metallization can be used in steel making furnaces and charging of blast furnaces which can improve production efficiency and decrease coke usage.

  5. Bacterial bioleaching of low grade nickel limonite and saprolite ores by mixotrophic bacteria

    Directory of Open Access Journals (Sweden)

    Chaerun Siti Khodijah

    2016-01-01

    Full Text Available Utilization of indigenous bacteria should be considered to establish a successful biohydrometallurgical process. In this study, mixrotrophic iron-oxidizing bacterial consortia consisting of Comamonas testosteroni, Alicyclobacillus ferrooxydans and Pantoea septic which were isolated from Indonesian mineral ores were examined to determine their abilities to recover nickel from limonite and saprolite ores in the bioleaching experiments using stirred tank reactors. The nickel bioleaching experiments inoculated with the bacterial consortia were carried out using coarse limonite ores and weathered saprolite ores with pulp density of 10% w/v. Abiotic controls were also carried out replacing the inocula by the sterile medium. The bioleaching processes were monitored by measuring Ni and Fe contents and pH of the leaching solution as well as the total bacterial enzymatic activity measured as FDA hydrolytic activity. The effect of leaching on the mineralogy of laterite ores was investigated by the scanning electron microscope equipped with energy-dispersive spectroscopy (SEM-EDS and X-ray powder diffraction (XRD. After 28 days of incubation, the FDA hydrolytic activity was observed in both bioleaching experiments containing limonite (17.2 μg fluorescein/mL and saprolite ores (16.9 μg fluorescein/mL. The leached Ni and Fe in the bioleaching experiments containing limonite ores (30% Ni and 5.6% Fe was greater than that in abiotic controls (1% Ni and 0.1% Fe with the pH range of 2.5 to 3.5. However, the bacterial consortia were less capable of bioleaching of Ni (2.5% with the similar leached Fe (6% from the saprolite ores. In abiotic controls, the medium pH remained relatively constant (pH 6. It was concluded that these bacterial isolated as the consortium were capable of nickel bioleaching (precious metal more effectively than iron (gangue metal, thus being applicable to the commercial processing of the difficult-to-process low-grade nickel laterite ores

  6. Biohydrometallurgy and membrane technology for resource recovery from low-grade ores and mining residuals

    International Nuclear Information System (INIS)

    Werner, Arite; Meschke, Katja; Bohlke, Kevin; Haseneder, Roland; Daus, Birgit; Repke, Jens-Uwe

    2017-01-01

    The recovery of strategic elements from secondary mineral resources and low grade ores is of increasing relevance, due to a changing global market as well as for reasons of sustainability. The present article shows the potential of biohydrometallurgy as an efficient technology for mobilization of metals from secondary mineral resources. Furthermore, the application of membrane separation as a successful technique for the recovery of metals from bioleaching solutions is presented. These issues are discussed within the scope of recent research projects.

  7. A Multistage Sulphidisation Flotation Procedure for a Low Grade Malachite Copper Ore

    OpenAIRE

    Tebogo P. Phetla; Edison Muzenda

    2010-01-01

    This study was carried out to develop a flotation procedure for an oxide copper ore from a Region in Central Africa for producing an 18% copper concentrate for downstream processing at maximum recovery from a 4% copper feed grade. The copper recoveries achieved from the test work were less than 50% despite changes in reagent conditions (multistage sulphidisation, use of RCA emulsion and mixture, use of AM 2, etc). The poor recoveries were attributed to the mineralogy of t...

  8. Radiation dose estimates from a mining plan for a high-grade uranium deposit

    International Nuclear Information System (INIS)

    Scott, L.M.

    1981-01-01

    The significance of gamma exposure to uranium miners has been recognized only in the last few years. Most ore deposits which have been underground mined, were 1% or less U 3 O 8 . Full-time mining of this grade ore can result in exposure exceeding 1 Rem per year. Several companies in Saskatchewan are planning to mine recently discovered ore bodies which contain ore pods in excess of 10% U 3 O 8 . The purpose of this paper is to present dose data which can be used to estimate gamma exposure from high-grade ore deposits, and to present mining techniques which will minimize miner exposure

  9. Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Wicakso, Doni Rahmat [Chemical Engineering Department, Faculty of Engineering, Lambung Mangkurat University, Jalan A. Yani KM. 36 Banjarbaru, 70714, South Kalimantan (Indonesia); Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Sutijan; Rochmadi [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Budiman, Arief, E-mail: abudiman@ugm.ac.id [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Center for Energy Studies, Gadjah Mada University, Sekip K1A, Yogyakarta, 55281 (Indonesia)

    2016-06-03

    Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 – 600 °C and catalyst weight between 0 – 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore pores to from gases, light hydrocarbon (bio-oil) and carbon, thus decreasing content tar in bio-oil and increasing the total gas product. In conclusion, the more low grade iron ore used as catalyst, the tar content in the liquid decrease, the H{sup 2} productivity increased and calorimetric value of bio-oil increased.

  10. Recovery of metals from low-grade ores by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Kamali, M.; Mulligan, C.N. [Concordia Univ., Dept. of Building, Civil and Environmental Engineering, Montreal, Quebec (Canada)]. E-mail: mulligan@civil.concordia.ca

    2002-06-15

    The main concern of this study is to develop a feasible and economical technique to microbially recover metals from oxide low-grade ores. Owing to the significant quantities of metals that are embodied in low - grade ores and mining residues, these are considered new sources of metals. On the other hand, they potentially endanger the environment, as the metals they contain may be released to the environment in a hazardous form. Hence, mining industries are seeking an efficient technique to handle these ores. Pyrometallurgical and hydrometallurgical techniques are either very expensive, energy intensive or have a negative impact on the environment. For these reasons, biohydrometallurgical techniques are coming into perspective. In this study, by employing Aspergillus niger, the feasibility of recovery of metals from a mining residue is shown. A. niger exhibits good potential in generating a variety of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulphuric acid was added to the medium. Different agricultural wastes such as potato peels were tested. In addition to this, different auxiliary processes were tried in order to either elevate the efficiency or reduce costs. Finally, maximum solubilization of 68%, 46% and 34% were achieved for copper, zinc and nickel, respectively. Also iron codissolution was minimized as only 7% removal occurred. (author)

  11. Recovery of metals from low-grade ores by Aspergillus niger

    International Nuclear Information System (INIS)

    Kamali, M.; Mulligan, C.N.

    2002-01-01

    The main concern of this study is to develop a feasible and economical technique to microbially recover metals from oxide low-grade ores. Owing to the significant quantities of metals that are embodied in low - grade ores and mining residues, these are considered new sources of metals. On the other hand, they potentially endanger the environment, as the metals they contain may be released to the environment in a hazardous form. Hence, mining industries are seeking an efficient technique to handle these ores. Pyrometallurgical and hydrometallurgical techniques are either very expensive, energy intensive or have a negative impact on the environment. For these reasons, biohydrometallurgical techniques are coming into perspective. In this study, by employing Aspergillus niger, the feasibility of recovery of metals from a mining residue is shown. A. niger exhibits good potential in generating a variety of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulphuric acid was added to the medium. Different agricultural wastes such as potato peels were tested. In addition to this, different auxiliary processes were tried in order to either elevate the efficiency or reduce costs. Finally, maximum solubilization of 68%, 46% and 34% were achieved for copper, zinc and nickel, respectively. Also iron codissolution was minimized as only 7% removal occurred. (author)

  12. Linking leach chemistry and microbiology of low-grade copper ore bioleaching at different temperatures

    Science.gov (United States)

    Jia, Yan; Sun, He-yun; Tan, Qiao-yi; Gao, Hong-shan; Feng, Xing-liang; Ruan, Ren-man

    2018-03-01

    The effects of temperature on chalcocite/pyrite oxidation and the microbial population in the bioleaching columns of a low-grade chalcocite ore were investigated in this study. Raffinate from the industrial bioleaching heap was used as an irrigation solution for columns operated at 20, 30, 45, and 60°C. The dissolution of copper and iron were investigated during the bioleaching processes, and the microbial community was revealed by using a high-throughput sequencing method. The genera of Ferroplasma, Acidithiobacillus, Leptospirillum, Acidiplasma, and Sulfobacillus dominated the microbial community, and the column at a higher temperature favored the growth of moderate thermophiles. Even though microbial abundance and activity were highest at 30°C, the column at a higher temperature achieved a much higher Cu leaching efficiency and recovery, which suggested that the promotion of chemical oxidation by elevated temperature dominated the dissolution of Cu. The highest pyrite oxidation percentage was detected at 45°C. Higher temperature resulted in precipitation of jarosite in columns, especially at 60°C. The results gave implications to the optimization of heap bioleaching of secondary copper sulfide in both enhanced chalcocite leaching and acid/iron balance, from the perspective of leaching temperature and affected microbial community and activity.

  13. RECOVERY OF URANIUM FROM LOW GRADE URANIUM BEARING ORES

    Science.gov (United States)

    Rhodes, H.B.; Pesold, W.F.; Hirshon, J.M.

    1959-06-01

    Recovery of U, Fe, and Al from Chattanooga shale is described. Ground shale (-4 to +325 mesh) is roasted to remove organic and volatile matter. The heated shale is then reacted with a chlorinating agent (CCl/sub 4/, COCl/sub 2/, Cl, and SCl) at 600 to 1000 C. The metal chloride vapor is separated from entrained solids and then contacted with a liquid alkali metal chloride which removes U. The U is reeovered by cooling and dissolving the bath followed by acidification and solvent extraction. A condensed phase of Al, Fe, and K chlorides is treated to separate Al as alumina by passing through a Fe/sub 2/O/ sub 3/ bed. The remaining FeCl/sub 3/ is oxidized by O/sub 2/ at 1000 C to form Fe/sub 2/O/sub 3/ and Cl/sub 2/. Alternatively, vapor from the U separation step may be passed to a liquid KCl bath at 500 to 650 C. The resulting mixture is oxidized to form Cl/sub 2/ and Fe/sub 2/O/sub 3/ + Al/sub 2/O/sub 3/. The Al and Fe are separated by reaction with NaOH at high temperatures and pressures. (T.R.H.)

  14. Recovery of uranium from low-grade sandstone ores and phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R H [United States Atomic Energy Commission, Washington, D. C. (United States)

    1967-06-15

    This paper is concerned principally with commercial-scale experience in the United States in the recovery of uranium from low-grade sources. Most of these operations have been conducted by the operators of uranium mills as an alternative to processing normal-grade ores. The operations have been generally limited, therefore, to the treatment of low-grade materials generated in the course of mining normal-grade ores. In some circumstances such materials can be treated by simplified procedures as an attractive source of additional production. The experience gained in uranium recovery from phosphate rock will be treated in some detail. The land pebble phosphate rock of central Florida generally contains about 0.01 to 0.02% U{sub 3}O{sub 8}. While no uranium is being recovered from this source at the present time, it does represent a significant potential source of by-product uranium production because of the large tonnages being mined. (author)

  15. Mining the high grade McArthur River uranium deposit

    International Nuclear Information System (INIS)

    Jamieson, B.W.

    2002-01-01

    The McArthur River deposit, discovered in 1988, is recognized as the world's largest, highest grade uranium deposit, with current mineable reserves containing 255 million lb U 3 O 8 at an average grade of 17.33% U 3 O 8 . In addition the project has resources of 228 million pounds U 3 O 8 averaging 12.02% U 3 O 8 . Mining this high-grade ore body presents serious challenges in controlling radiation and in dealing with high water pressures. Experience from the underground exploration programme has provided the information needed to plan the safe mining of the massive Pelite ore zone, which represents the most significant source of ore discovered during the underground drilling programme, with 220 million pounds of U 3 O 8 at an average grade in excess of 17%. Non-entry mining will be used in the high-grade ore zones. Raise boring will be the primary method to safely extract the ore, with all underground development in waste rock to provide radiation shielding. Water will be controlled by grouting and perimeter freezing. The ore cuttings from the raise boring will be ground underground and pumped to surface as slurry, at an average daily production of 150 tonnes. The slurry will be transported to the Key Lake mill and diluted to 4% before processing. The annual production is projected to be 18 million lb U 3 O 8 . The paper focuses on the activities undertaken since discovery, including the initiation of the raise bore mining method utilized to safely mine this high grade ore body. Radiation protection, environmental protection and worker health and safety are discussed in terms of both design and practical implementation. (author)

  16. Status Report from Canada [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Thunaes, A [Eldorado Mining and Refining Ltd., Ottawa (Canada)

    1967-06-15

    The Canadian production of uranium increased in a spectacular manner during the period 1955-1959 from 1000 to 15 500 tons U{sub 3}O{sub 8} per year. Since 1959 the production has declined to the 1966 level of 3900 tons U{sub 3}O{sub 8} per year; stretch-out of contracts and government stockpiling programmes has made the decline gradual, and is maintaining the current rate of production until 1970. Nineteen mills were in operation during the period of peak production but only three are operating today. Ten mills were shut down and dismantled because of exhaustion of ore bodies or because the operation was uneconomical; six mills are maintained in stand-by condition. The total daily capacity of mills in operation or standing by is about 28 000 tons ore, but some of these mills would not be reopened unless an appreciable increase in uranium price occurs. The tide of uranium demand is about ready to turn and prospecting for uranium is very active this year, particularly in the Elliot Lake and Beaverlodge areas. The estimates for uranium demand in 1975-1980 are such that new ore will have to be found and developed, and new treatment plants must be built. The new ore that is found will likely be of lower grade or more expensive to mine than most of the current proven reserves in Canada and the most efficient methods of treatment will be needed to avoid excessive increases in production costs. This seems an opportune time to review Canadian milling of uranium ore, the improvements that have been made and development work towards further improvements.

  17. Pilot plant studies on the extraction of antimony metal from lower grade krinj stibnite ore

    International Nuclear Information System (INIS)

    Rehman, W.; Riaz, M.; Ishaq, M.

    2013-01-01

    Antimony is a silvery white, brittle and crystalline solid which is extensively consumed in lead acid batteries, antimonial lead alloys, flame retardants and a variety of metallic products. The antimony content of commercial ores range from 5-60% and determines the method of extraction, either pyrometallurgical or hydrometallurgical. The present study focuses on pilot plant scale extraction of antimony metal from lower grade stibnite ore of Krinj (Chitral) without the use of iron scrap, thus eliminating the second step of iron removal in conventional direct reduction method. A tilting gas fired furnace with digital temperature control system and a heat recuperator was designed to optimize the operating parameters for extraction of antimony metal. Weight ratios of flux and reductant, operating time and operating temperature were optimized. Highest percentage recovery and purity were achieved using soda ash as a flux, at a temperature of 900 degree C for 2 hours. (author)

  18. Gold grade of epithermal gold ore at Lamuntet, Brang Rea, West Sumbawa District, West Nusa Tenggara Province, Indonesia

    Science.gov (United States)

    Ernawati, Rika; Idrus, Arifudin; TBMP, Himawan

    2017-06-01

    Lamuntet is one of gold ore mining area carried out by the Artisanal Small scale Gold Mining (ASGM) located in West Sumbawa, Indonesia. Most of the miners at this area are not the local miners but also those from other regions. Mineralization of this area is strong identified as low sulfidation epithermal system. There are two blocks of this mining location, namely, Ngelampar block with an area of 0.164 km2 and Song block with an area of 0.067 km2. This study was focused on Ngelampar block. The characteristic of epithermal system is the existence of quartz vein with comb, vuggy, and sugary texture. The aim of this research was to analyze the gold grade and other metals, such as Cu, Ag, Pb, As, Zn, and Hg. The research methods included literature study from previous researches, field work, laboratory work, and interpretation. The literature study was performed on previous researches with similar study area. The field work comprised of direct observation and sampling. Fieldwork was done for a week to obtain gold ore/vein. Sixteen samples were analyzed to obtain the grade of ore/metal. The Hg laboratory analysis was then performed on the six samples with the highest gold grade. Laboratory works were conducted at Intertek Jakarta by using Fire Assay (FA) for gold grade and Atomic Absorption Spectrophotometry (AAS) for Cu, Ag, Pb, As, Zn, and Hg. Results of the analysis showed the range of Au was grade (0.1 ppm - 27.8 ppm), Cu was 26 ppm -1740 ppm, Pb was 101 ppm- >4000 ppm, Zn of 73 ppm- >10,000 ppm, Ag of 3 ppm -185 ppm, As was 150 ppm-6530 ppm, and Hg of 0.08 ppm - 1.89 ppm. L1 and L15 had high grade for all values (Au, Ag, Zn, Cu, As, and Hg). Gold mineralization was formed as electrum because of Ag content is higher than 20%. Associated minerals of the samples in the study area were galena, sphalerite, arsenopyrite, and chalcopyrite which showed the characteristic of rich base metal of Pb, Zn, and Cu at LS epithermal.

  19. Pb(II), Cd(II) and Zn(II) adsorption on low grade manganese ore ...

    African Journals Online (AJOL)

    Low grade manganese ore (LMO) of Orissa containing 58.37% SiO2, 25.05% MnO2, 8.8% Al2O3, and 5.03% Fe2O3 as the main constituents was taken to study its adsorption behaviour for Pb(II), Cd(II) and Zn(II) from aqueous solutions. The XRD studies showed the crystalline phases to be quartz, ß-MnO2, d-MnO2 and ...

  20. Petrographic-mineralogical characterization with liberation grade, X ray and chemical diffractometry in ore samples of Itataia-CE mine

    International Nuclear Information System (INIS)

    Salas, H.T.

    1985-01-01

    From samples collected by geologists in several points of G2 and G3 gallery of Itataia Uranium Phosphate mine, intended to get knowledge about several lithologic types of ores, mainly its alteration grades. Petrographic-mineralogical studies, liberation grade calculation of apatite, X-ray diffractometry analysis and dosage of oxydes by X-ray fluorencence are executed. (C.M.) [pt

  1. Studies on the recovery of uranium from low-grade ores in India

    International Nuclear Information System (INIS)

    Jayaram, K.M.V.; Dwivedy, K.K.; Deshpande, A.S.; Ramachar, T.M.

    1976-01-01

    Investigations were carried out to utilize the available para-marginal and low-grade ores - chlorite schists, amphibolites, carbonate ores, clays and quartzites - analysing between 0.027 and 0.08% U 3 O 8 . In addition, tests were undertaken on the technical and economic feasibility of recovering uranium as a byproduct from the copper flotation tailings and phosphorites. Heap and bacterial leaching tests were conducted on quartz-chlorite schists from the Singhbhum district, Bihar, analysing about 0.03% U 3 O 8 . Studies also showed that the ores harbour active Ferrobacillus ferrooxidans. Studies on 10-mesh samples of amphibolites from Inderwa, Bihar, (0.08% U 3 O 8 ) showed that only 32.8% recovery could be obtained by wet tabling and 85% by agitation leaching, while static leaching tests yielded 81% recovery in 24 hours of contact time. Similar tests on calcareous phyllites (0.05% U 3 O 8 ) with 30 kg/t Na 2 CO 3 and 8 kg/t NaHCO 3 yielded 86% uranium leachability at ambient temperature. Biogenic uraniferous clay from Udaisagar (0.029% U 3 O 8 ) yielded 43.3% uranium recovery using 1000 l/t of neutral water for 6 h. Percolation leaching tests were conducted with hard quartzites (0.06% U 3 O 8 ), and the results showed that 81% uranium could be recovered in 24 days. Although preliminary ore dressing studies on tailings obtained from the copper flotation (0.013% U 3 O 8 ) at Surda yielded a concentrate analysing 0.063% U 3 O 8 at 66% recovery, recent tests on the tailings from the copper concentrator indicated only 48% recovery at a grade of 0.112% owing to decrease in the feed grade. Studies on the utilization of large-capacity gravity machines and selective mining of uranium-rich copper lodes may render this source economic. Preliminary studies on a phosphorite sample containing 22.0% P 2 O 5 and 0.04% U 3 O 8 from the Mussorie area in Uttar Pradesh on calcination followed by scrubbing yielded a sand enriched in P 2 O 5 values (33.7% P 2 O 5 at 92.5% recovery) but

  2. Metal recovery from high-grade WEEE

    DEFF Research Database (Denmark)

    Bigum, Marianne; Brogaard, Line Kai-Sørensen; Christensen, Thomas Højlund

    2012-01-01

    . The modeled metallurgical treatment facility included a Kaldo plant, a converter aisle, an anode refinery and a precious metal refinery. The metallurgic treatment showed significant environmental savings when credited the environmental load from avoided production of the same amount of metals by mining...... and refining of ore. The resource recovery per tonne of high-grade WEEE ranged from 2 g of palladium to 386 kg of iron. Quantified in terms of person-equivalents the recovery of palladium, gold, silver, nickel and copper constituted the major environmental benefit of the recovery of metals from WEEE....... These benefits are most likely underestimated in the model, since we did not find adequate data to include all the burdens from mining and refining of ore; burdens that are avoided when metals are recovered from WEEE. The processes connected to the pre-treatment of WEEE were found to have little environmental...

  3. Use of neutron capture gamma radiation for determining grade of iron ore in blast holes and exploration holes

    International Nuclear Information System (INIS)

    Eisler, P.L.; Huppert, P.; Mathew, P.J.; Wylie, A.W.; Youl, S.F.

    1977-01-01

    Neutron radiative capture and neutron-neutron logging have been applied to determining the grade of ore in dry blast holes and a dry exploration hole drilled into a layered iron deposit. Both thermal and epithermal neutron responses were measured as well as the gamma-ray responses due to neutron capture by iron and by hydrogen present in hydrated minerals. The results were fitted by a stepwise multiple linear regression technique to give expressions for mean grade of ore in the drill hole and 95% confidence intervals for estimation of this mean. For an overall range of ore grades of 20-68% Fe and a mean grade of 63% Fe, the confidence interval for prediction of mean grade for the neutron-gamma technique was 0.3% Fe for pooled data from all five blast holes and 0.8% Fe for a single hole. It was also shown that for this type of layered deposit a simpler neutron-neutron log incorporating simultaneous measurement of both thermal and epithermal neutron responses gave almost as good a grade prediction result for pooled results from five drill holes, namely 63+-0.4% Fe, as that obtained by the neutron-gamma technique. The results of both types of log are compared with those obtained by the spectral gamma-ray backscattering [Psub(z)] technique, or by logging of natural gamma radiations from the shale component of the ore. From this comparison conclusions are drawn regarding the most suitable technique to employ for determining grade of iron ore in various practical logging situations. (author)

  4. Biocatalytic and chemical leaching of a low-grade nickel laterite ore

    Science.gov (United States)

    Ciftci, Hasan; Atik, Suleyman; Gurbuz, Fatma

    2018-04-01

    Nickel and cobalt recovery from a low-grade nickel laterite ore, supplied from Çaldağ deposit (Manisa, Turkey) were investigated by bio and chemical leaching processes. The fungus, Aspergillus niger was used for biocatalytic leaching experiments. The effects of parameters (solid ratio and sucrose concentration) on the biocatalytic leaching of the ore were initially tested in flasks to obtain the optimum conditions for the A. niger. Then chemical leaching was applied as a comparison to bioleaching, using organic acids (citric, oxalic, acetic and gluconic acids) as well as a mixture of acids. According the results, the maximum dissolution yield of nickel, cobalt and iron were detected respectively as 95.3%, 74.3% and 50.0% by biocatalytic processes which containing 25% (w/v) sucrose and 1% (w/v) solids. The increase in the solid ratio adversely influenced the biocatalytic activity of A. niger. Finally, further tests in reactors (v = 1 and 10 L) were performed using the optimum conditions from the flask tests. The difference in metals recovery between biocatalytic and chemical leaching was significantly important. Bioleaching produced higher Ni and Co extractions (34.3-75.6%) than chemical process.

  5. Field measurements of mixed exposure of operators to radioactive aerosol, gas and quartz in confinement of mining equipment cabs during open-pit mining of high-grade uranium ores

    International Nuclear Information System (INIS)

    Yoshida, K.; Atiemo, M.A.; Markham, J.W.

    1982-07-01

    A series of field measurements of miners mixed exposure to radon and daughters, uranium ore dust and respirable quartz, was conducted in an open-pit mine in Northern Saskatchewan during 1980-81. Control of radon gas levels in the mining equipment cabs is required. Dust may be reduced by minimizing the resuspension of dust from contaminated surfaces within the cabs

  6. Preconcentration of a low grade uranium ore in CPDU and laboratory investigation to optimize the dewatering conditions of the preconcentration products

    International Nuclear Information System (INIS)

    Cristovici, M.A.; Berry, T.F.; Raicevic, M.M.; Brady, E.L.; Bredin, E.L.; Leigh, G.W.; Rouleau, J.P.

    1982-04-01

    A process consisting of pyrite flotation and magnetic concentration of radionuclides was developed by CANMET over several years, to preconcentrate low grade uranium ores prior to leaching. When the economics of the preconcentration-leaching technology was compared with the leaching of the entire ore after pyrite flotation (Base Case variant), the preconcentration method appeared to be economically less advantageous than expected, due to the high cost of dewatering the preconcentration products. Further investigations examined in-depth the metallurgy and dewatering of the two variants: preconcentration and base case. A typical low grade uranium ore from Elliot Lake area was used. The metallurgy was compared based on data from continuous operation (CPDU). In the preconcentration variant the amount of ore directed to leaching was reduced to more than one third of that processed in the base case, while the radionuclide concentration became more than three times higher. However, by preconcentration 7% of the uranium was lost before leaching. Systematic laboratory-scale settling and filter tests optimized the dewatering conditions of the preconcentration technology to the extent that rates similar to those of the base case were obtained

  7. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-06-15

    Proceedings of a panel convened by the IAEA in Vienna, 27 June - 1 July 1966. The 22 specialists from 15 countries and one international organization who attended the meeting were asked to give an appraisal of the current situation with regard to the processing of low-grade uranium ores and make recommendations for a possible IAEA programme of activities. This publication covers the work of the panel. Contents: Status reports (13 reports); Technical reports (13 reports); Summaries of discussions; Recommendations of the panel. Each report is in its original language (16 English, 4 French, 2 Russian and 4 Spanish) and each technical report is preceded by an abstract in English and one in the original language if this is not English. The summaries of discussions and the panel recommendations are in English. (author)

  8. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    International Nuclear Information System (INIS)

    1967-01-01

    The 22 specialists from 15 countries and one international organization who attended the meeting were asked to give an appraisal of the current situation with regard to the processing of low-grade uranium ores and make recommendations for a possible IAEA programme of activities. This publication covers the work of the panel. Contents: Status reports (13 reports); Technical reports (13 reports); Summaries of discussions; Recommendations of the panel. Each report is in its original language (16 English, 4 French, 2 Russian and 4 Spanish) and each technical report is preceded by an abstract in English and one in the original language if this is not English. The summaries of discussions and the panel recommendations are in English. (author)

  9. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-06-15

    The 22 specialists from 15 countries and one international organization who attended the meeting were asked to give an appraisal of the current situation with regard to the processing of low-grade uranium ores and make recommendations for a possible IAEA programme of activities. This publication covers the work of the panel. Contents: Status reports (13 reports); Technical reports (13 reports); Summaries of discussions; Recommendations of the panel. Each report is in its original language (16 English, 4 French, 2 Russian and 4 Spanish) and each technical report is preceded by an abstract in English and one in the original language if this is not English. The summaries of discussions and the panel recommendations are in English. (author)

  10. On a Bayesian estimation procedure for determining the average ore grade of a uranium deposit

    International Nuclear Information System (INIS)

    Heising, C.D.; Zamora-Reyes, J.A.

    1996-01-01

    A Bayesian procedure is applied to estimate the average ore grade of a specific uranium deposit (the Morrison formation in New Mexico). Experimental data taken from drilling tests for this formation constitute deposit specific information, E 2 . This information is combined, through a single stage application of Bayes' theorem, with the more extensive and well established information on all similar formations in the region, E 1 . It is assumed that the best estimate for the deposit specific case should include the relevant experimental evidence collected from other like formations giving incomplete information on the specific deposit. This follows traditional methods for resource estimation, which presume that previous collective experience obtained from similar formations in the geological region can be used to infer the geologic characteristics of a less well characterized formation. (Author)

  11. Bioleaching of low grade uranium ore containing pyrite using A. ferrooxidans and A. thiooxidans

    International Nuclear Information System (INIS)

    Alexey Borisovich Umanskii; Anton Mihaylovich Klyushnikov

    2013-01-01

    A process of uranium extraction from ore containing 3.1 % pyrite by bacterial leaching was investigated in shaken flasks during 90 days. The highest uranium recovery amounting to 85.1 % was obtained using binary mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans that was exceeding results obtained by traditional acid leaching technique up to 27 %. High uranium recovery was founded to be due to the high degree of pyrite dissolution that can be readily achieved by bacterial leaching (up to 98.0 %). (author)

  12. Beneficiation studies on low-grade complex polymetallic lead-zinc ore of duddar (lasbela) Balochistan, Pakistan

    International Nuclear Information System (INIS)

    Bhatti, M.R.; Kazim, K.R.; Mehmood, R.; Akram, A.

    2016-01-01

    A bench-scale beneficiation study was performed on low-grade complex lead-zinc ore of Duddar area, District Lasbela, Balochistan Province, Pakistan. The polymetallic ore under investigation contains galena and sphalerite as valuable minerals of lead and zinc. The low-grade ore was upgraded by selective sequential froth flotation technology to recover both minerals. An effort was made to investigate the effect of important variables on grade and recovery of concentrates and to design the process flow sheet. Different parameters of flotation process such as particle size of the feed, pH and % solids of the pulp, speed of impeller, type of reagents (collectors, frothers, regulators and modifiers) and their quantities, conditioning time and flotation time were optimized to attain maximum grade and recovery of respective concentrates. The rougher concentrates obtained were subjected to one regrinding and two cleaning operations to achieve higher-grade concentrates of both metals. Bench-scale flotation tests show that it is possible to obtain a lead concentrate assaying 65.24% Pb with recovery rate of 81.32% and a zinc concentrate containing 55.63% Zn content with recovery rate of 80.28%. Both the concentrates meet the specifications required for metallurgical and chemical grades. (author)

  13. Heap-leaching of low-grade uranium ore at SOMAIR: from laboratory tests to production of 700 tonnes U per year

    Energy Technology Data Exchange (ETDEWEB)

    Durupt, N.; Blanvillain, J.J., E-mail: nicolas.durupt@areva.com [AREVA NC, Service d' Etudes de Procedes et d' Analyses (SEPA), Bessines sur Gartempe (France)

    2010-07-01

    In 2006, SOMAIR decided to increase the uranium production by 50% using heap leaching for the treatment of low grade ores. These ores, which come from different ores with various properties, have been studied in four steps: Lab tests: to compare the ores (characterization, acid consumptions, recovery); Column tests on an average sample: to define significant parameters for a feasibility study; Column tests on specific samples: to optimize recovery for each ore and identify problems of percolation due to the clays; and, Pilot tests in large boxes (stalls): to validate process parameters. Uranium production by heap leaching started commercially in July 2009. (author)

  14. Gas migration characteristics of highly compacted bentonite ore

    International Nuclear Information System (INIS)

    Tanaka, Yukihisa; Hironaga, Michihiko

    2010-01-01

    In the current concept of repository for radioactive waste disposal, compacted bentonite will be used as an engineered barrier mainly for inhibiting migration of radioactive nuclides. Hydrogen gas can be generated inside the engineered barrier by anaerobic corrosion of metals used for containers, etc. If the gas generation rate exceeds the diffusion rate of dissolved gas inside of the engineered barrier, gas will accumulate in the void space inside of the engineered barrier until its pressure becomes large enough for it to enter the bentonite as a discrete gaseous phase. It is expected to be not easy for gas to entering into the bentonite as a discrete gaseous phase because the pore of compacted bentonite is so minute. Gas migration characteristics of highly compacted powdered bentonite are already reported by CRIEPI. In this report, gas migration characteristics of bentonite ore, which is a candidate for construction material of repository for radioactive waste, is investigated. The following conclusions are obtained through the results of the gas migration tests which are conducted in this study: 1) When the total gas pressure exceeds the initial total axial stress, the total axial stress is always equal to the total gas pressure because specimens shrink in the axial direction with causing the clearance between the end of the specimen and porous metal. By increasing the gas pressure more, gas breakthrough, which defined as a sudden and sharp increase in gas flow rate out of the specimen, occurs. Therefore gas migration mechanism of compacted bentonite ore is basically identical to that of compacted powdered bentonite. 2) Hydraulic conductivity measured after the gas breakthrough is somewhat smaller than that measured before the gas migration test. This fact means that it might be possible to neglect decline of the function of bentonite as engineered barrier caused by the gas breakthrough. These characteristics of compacted bentonite ore are identical to those of

  15. Optimization of operating parameters and rate of uranium bioleaching from a low-grade ore

    International Nuclear Information System (INIS)

    Rashidi, A.; Roosta-Azad, R.; Safdari, S.J.

    2014-01-01

    In this study the bioleaching of a low-grade uranium ore containing 480 ppm uranium has been reported. The studies involved extraction of uranium using Acidithiobacillus ferrooxidans derived from the uranium mine samples. The maximum specific growth rate (μ max ) and doubling time (t d ) were obtained 0.08 h -1 and 8.66 h, respectively. Parameters such as Fe 2+ concentration, particle size, temperature and pH were optimized. The effect of pulp density (PD) was also studied. Maximum uranium bio-dissolution of 100 ± 5 % was achieved under the conditions of pH 2.0, 5 % PD and 35 deg C in 48 h with the particles of d 80 = 100 μm. The optimum concentration of supplementary Fe 2+ was dependent to the PD. This value was 0 and 10 g of FeSO 4 ·7H 2 O/l at the PD of 5 and 15 %, respectively. The effects of time, pH and PD on the bioleaching process were studied using central composite design. New rate equation was improved for the uranium leaching rate. The rate of leaching is controlled with the concentrations of ferric and ferrous ions in solution. This study shows that uranium bioleaching may be an important process for the Saghand U mine at Yazd (Iran). (author)

  16. A New Heterotrophic Strain for Bioleaching of Low Grade Complex Copper Ore

    Directory of Open Access Journals (Sweden)

    Kaijian Hu

    2016-02-01

    Full Text Available A new heterotrophic strain, named Providencia sp. JAT-1, was isolated and used in bioleaching of low-grade complex copper ore. The strain uses sodium citrate as a carbon source and urea as a nitrogen source to produce ammonia. The optimal growth condition of the strain is 30 C, initial pH 8, sodium citrate 10 g/L and urea 20 g/L, under which the cell density and ammonia concentration in the medium reached a maximum of 4.83 × 108 cells/mL and 14 g/L, respectively. Ammonia produced by the strain is used as the main lixiviant in bioleaching. Bioleaching results revealed that higher strain growth led to a higher copper recovery, while higher pulp density will cause a greater inhibitory effect on strain growth and ammonia production. The copper extraction reached the highest value of 54.5% at the pulp density of 1%. Malachite, chrysocolla and chalcocite are easy to leach out in this bioleaching system while chalcopyrite is difficult. Results of comparative leaching experiments show that bioleaching using JAT-1 is superior to ammonia leaching at the same condition. The metabolites produced by the strain other than ammonia are also involved in bioleaching.

  17. Status Report from Sweden [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, A [AB Atomenergi, Stockholm (Sweden)

    1967-06-15

    The Ministry of Education was authorized in November 1945 to appoint a commission to study the organization of nuclear energy research. In April 1947 this commission, the Swedish Atomic Energy Commission, proposed the formation of a semi-state-owned company to be a central body for applied research work and development in the nuclear energy field in Sweden. In November 1947 the Atomic Energy Company (AB Atomenergi) had its statutory meeting. The State owns 4/7 of the share capital and the remaining 3/7 is owned by 71 private and municipal share-holders. Except for a part of the stock capital, all investments and running costs of the company have been financed by the Government. The company is in practice answerable to the Department of Commerce which has an advisory body, the Atomic Energy Board. AB Atomenergi is responsible for Government-financed research on the industrial applications of nuclear energy, the milling of uranium ores and refining of uranium. The total number of employees is at present about 1400, 800 of which work at the company's research establishment Studsvik about 120 km south of Stockholm. As early as 1945 the Research Institute of the Swedish National Defence started work in the field of uranium processing. Similar work was also started quite early by the Boliden Mining Company, the Swedish Shale Oil Company and Wargons AB. After the establishment of AB Atomenergi, all work in the uranium processing field was transferred to this company. In fact one of the main reasons for the formation of AB Atomenergi was the need for Swedish uranium production as there was no possibility of importing uranium at that time. As a result of research and development in uranium processing a pilot plant at Kvarntorp near Orebro in central Sweden started milling a low-grade uranium ore (shale) in 1953. The capacity of this plant was 5-10 tons of uranium a year. A uranium mill at Ranstad in south-west Sweden, near Skovde, with a capacity of 120 tons of uranium a

  18. Method of continuous pressure leaching of ores

    International Nuclear Information System (INIS)

    Fiala, P.; Baloun, S.; Polansky, M.

    1987-01-01

    Ore leaching, especially suspensions of ground ore or fine ore fractions from physical treatment was divided into two operations. The former, i.e., ore mixing with technical grade concentrated sulfuric acid proceeded in a separate mixer. The mixture was then transported into an autoclave where the actual leaching proceeded for 2 to 4 hours. The extracted mixture was discharged through the autoclave bottom. The leaching autoclave used can be without any inner structures. The separation of mixing from the actual leaching allows processing ores with high levels of clay components, increasing operating reliability of the facility, reducing consumption of special structural materials and energy, and increasing process efficiency. (E.S.)

  19. Analysis of material flow in a utillzation technology of low grade manganese ore and sulphur coal complementary

    Science.gov (United States)

    Wang, Bo-Zhi; Deng, Biao; Su, Shi-Jun; Ding, Sang-Lan; Sun, Wei-Yi

    2018-03-01

    Electrolytic manganese is conventionally produced through low-grade manganese ore leaching in SO2, with the combustion of high sulfur coal. Subsequently the coal ash and manganese slag, produced by the combustion of high sulfur coal and preparation of electrolytic manganese, can be used as raw ingredients for the preparation of sulphoaluminate cement. In order to realize the `coal-electricity-sulfur-manganese-building material' system of complementary resource utilization, the conditions of material inflow and outflow in each process were determined using material flow analysis. The material flow models in each unit and process can be obtained by analyzed of material flow for new technology, and the input-output model could be obtained. Through the model, it is possible to obtain the quantity of all the input and output material in the condition of limiting the quantity of a substance. Taking one ton electrolytic manganese as a basis, the quantity of other input material and cements can be determined with the input-output model. The whole system had thusly achieved a cleaner production level. Therefore, the input-output model can be used for guidance in practical production.

  20. A study on the upgrading by physical means of low grade uranium ore from Phu Wiang District

    International Nuclear Information System (INIS)

    Wihokratna, W.

    1980-01-01

    The purpose of this thesis is to upgrade the uranium ore at Phu Wiang district. Because of the fine grains and high degree of dissemination of uranium in ores, resulting practically complete envelopment of the uranium minerals by the gangue minerals, the ore must first undergo digestion in order to reveal the uranium minerals. After digestion, sodium hydroxide of 0.05 normal was added to the ore and the mixture was fed into the agitator provided with baffles and two specially designed propellers. Due to the 'Push - Pull' motion of the propellers a zone of specially high turbulence was created between them. Also in this region higher concentration of uranium is revealed and the high concentrated uranium ore was regularly stripped off for further analysis. It was found that by using mineral of grain size of 100 mesh and 0.0187% of uranium content a concentration up to 0.063% uranium content (an upgrading better than by a factor of three times) was achieved with the above method. The uranium content was analyzed with 3'' x 3'' NaI (Tl) detector and 1024 channels MCA

  1. Recent Pilot Plant Experience on Alkaline Leaching of Low Grade Uranium Ore in India

    Energy Technology Data Exchange (ETDEWEB)

    Suri, A. K; Ghosh, S. K.; Padmanabhan, N. P.H., [Bhabha Atomic Research Centre, Mumbai (India)

    2014-05-15

    Uranium deposits in India are low grade and are relatively smaller in extent as compared to present worldwide commercial practice. So far, the vein type deposits of Singhbhum Thrust Belt (STB) are being exploited for meeting the Indian requirements of uranium. The deposits are currently processed by acid leaching in the mills located at Jaduguda and Turamdih near Jamshedpur in Jharkhand State of India. The deposits at Jaduguda and Narwapahar are being mined by underground mining and are processed in Jaduguda mill using airagitated Pachucas. The deposits at Banduhurang and Turamdih are being mined by open cast and underground mining respectively and are processed at Turamdih by acid leaching in mechanically agitated reactors. The occurrences of uranium in North East and Northern part of Kadapa basin are relatively moderate in size and are expected to be processed in the near future by acid leaching. Uranium is also found to occur near Tummalapalle in granitic and limestone host rocks in Southern part of Kadapa basin (Andhra Pradesh) and in Gogi in Bhima basin (Karnataka). The deposit in Tummalapalle is relatively lower in grade (≈ 0.042% U{sub 3}O{sub 8}) but is a reasonably large reserve, whereas that in Gogi is rich in uranium content (≈0.18% U{sub 3}O{sub 8}) but is relatively small reserve. Laboratory tests based on alkaline leaching have been carried out on both types of deposits. Studies for Tummalapalle deposits have been extended to pilot plant level and a complete flow sheet has been established with the regeneration and recirculation of lixiviants and recovery of sodium sulphate as a by-product. The process involves alkaline leaching under oxygen pressure in batch type and/or continuous leach reactor using sodium carbonate/bicarbonate as a leaching media and uranium is recovered as sodium diuranate. Based on the techno-economic evaluation of the process, an industrial scale mill (3 000 tonnes ore/day) is being set up at Tummalapalle in Andhra Pradesh

  2. O-Ring sealing arrangements for ultra-high vacuum systems

    Science.gov (United States)

    Kim, Chang-Kyo; Flaherty, Robert

    1981-01-01

    An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

  3. Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations

    Science.gov (United States)

    Saramak, Daniel; Krawczykowska, Aldona; Młynarczykowska, Anna

    2014-10-01

    This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

  4. Midwest Joint Venture high-grade uranium mining

    International Nuclear Information System (INIS)

    Fredrickson, H.K.

    1992-01-01

    Midwest Joint Venture (MJV) owns a high-grade uranium deposit in northern Saskatchewan. The deposit is located too deep below surface to be mined economically by open pit methods, and as a consequence, present plans are that it will be mined by underground methods. High-grade uranium ore of the type at MJV, encased in weak, highly altered ground and with radon-rich water inflows, has not before been mined by underground methods. The test mining phase of the project, completed in 1989, had three objectives: To evaluate radiation protection requirements associated with the handling of large quantities of radon-rich water and mining high-grade uranium ore in an underground environment; to investigate the quantity and quality of water inflows into the mine; and, to investigate ground conditions in and around the ore zone as an aid in determining the production mining method to be used. With information gained from the test mining project, a mining method for the production mine has been devised. Level plans have been drawn up, ventilation system designed, pumping arrangements made and methods of ore handling considered. All this is to be done in a manner that will be safe for those doing the work underground. Some of the mining methods planned are felt to be unique in that they are designed to cope with mining problems not known to have been encountered before. New problems underground have required new methods to handle them. Remote drilling, blasting, mucking and backfilling form the basis of the planned mining method

  5. Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

    Science.gov (United States)

    Li, Wen-juan; Liu, Shuang; Song, Yong-sheng; Wen, Jian-kang; Zhou, Gui-ying; Chen, Yong

    2016-12-01

    The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation-gold concentrate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concentrate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

  6. Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid

    International Nuclear Information System (INIS)

    Madakkaruppan, V.; Pius, Anitha; Sreenivas, T.; Giri, Nitai; Sarbajna, Chanchal

    2016-01-01

    Highlights: • U leaching from a low-grade Si-rich ore studied in H_2SO_4 medium with (MW) irradiation. • MW heating is more efficient in terms of U recovery, kinetics and purity of liquor. • U leachability of 84% obtained in 90 min at 95 °C with 0.38 M H_2SO_4 at 450 mVwith MW heating • Conventional conductive heating gave about 74% leachability with less purity liquor. • U leaching was found follow product layer diffusion as controlling mechanism. - Abstract: This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12–0.50 M), redox potential (400–500 mV), particle size (600–300 μm) and temperature (35°–95 °C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism.

  7. Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Madakkaruppan, V. [Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad 500016 (India); Pius, Anitha, E-mail: dranithapius@gmail.com [Department of Chemistry, Gandhigram Rural Institute, Gandhigram, Dindigul District, Tamil Nadu 624302 (India); Sreenivas, T.; Giri, Nitai [Mineral Processing Division, Bhabha Atomic Research Center, AMD Complex, Begumpet, Hyderabad 500016 (India); Sarbajna, Chanchal [Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad 500016 (India)

    2016-08-05

    Highlights: • U leaching from a low-grade Si-rich ore studied in H{sub 2}SO{sub 4} medium with (MW) irradiation. • MW heating is more efficient in terms of U recovery, kinetics and purity of liquor. • U leachability of 84% obtained in 90 min at 95 °C with 0.38 M H{sub 2}SO{sub 4} at 450 mVwith MW heating • Conventional conductive heating gave about 74% leachability with less purity liquor. • U leaching was found follow product layer diffusion as controlling mechanism. - Abstract: This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12–0.50 M), redox potential (400–500 mV), particle size (600–300 μm) and temperature (35°–95 °C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism.

  8. Status report from South Africa [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, R E [Atomic Energy Board, Pretoria (South Africa)

    1967-06-15

    Most of the research work on the processing of uranium ores in South Africa is being conducted by the Extraction Metallurgy Division of the S.A. Atomic Energy Board. Nevertheless, a considerable amount of applied research has been done by the different mining groups concerned with the operation of uranium plants, and also by the Transvaal and Orange Free State Chamber of Mines research laboratories. There is, however, very close collaboration between the various research groups and the Atomic Energy Board and the main research described is conducted on a collaborative basis.

  9. Study of the sulfuric acid leaching and bacterial leaching of low grade uranium ore by orbital shaker experiment

    International Nuclear Information System (INIS)

    Li Guangyue; Liu Yulong; Wang Yongdong; Ding Dexin

    2009-01-01

    The sulphuric acid leaching and bacteria leaching by orbital shaker experiments were conducted for the low grade uranium ore from a uranium mine in Guangdong Province. The results show that, when the concentration of sulphuric acid and that of slurry were 30 g/L and 25%, respectively, the conditions were most favourable for sulphuric acid leaching and the rate of leaching reached 92.92%, that, when pH value was 1.5, inoculation amount, 10%, concentration of slurry, 10%, the conditions were most favourable for bacteria leaching and the rate of leaching reached 95.93%, that, compared with sulphuric acid leaching, bacteria leaching decreased sulphuric acid consumption by 17.2% and increased the rate of leaching by 3%, and that, under the most favourable conditions for suphuric acid leaching, if 1% natrium chlorate was added, the rate of leaching increased to 96.46%, but 10 kg of natrium chlorate was consumed for 1 ton of uranium ore. (authors)

  10. Impact Of Low Grade Uranium Ores On The Echo System and the Workers of Phosphate Industry

    International Nuclear Information System (INIS)

    Anwar, S.M.

    1999-01-01

    The present study aims to investigate the influence of uranium present in phosphate rocks as an environmental factor in the ccho system and on the workers of Abu-Zaabal Phosphate Company subjected to the inhalation of big quantities of rock phosphate dust during the benefication of the ore and the production of the fertilizers. Besides. extra amount of uranium reach the workers also through two path ways.The first is direct through eating contaminated planted grown in the near by area.The second is indirect through eating animals fed with contaminated plants. The uranium content is estimated in the soil samples at different depths, water (irrigation and drainage), air samples and plant samples (shoot and root) in Berseem from the four directions, urine samples from twenty workers in charge of the processing of phosphate compared to twenty volunteers far from the contaminated area.The results showed an elevated values for phosphorus and uranium in the air, water. soil and plant (Berseem) around Abu Zaabal Factory and extending to about 2 km from all directions. Urine may be considered as a biological indicator medium for the uptake of uranium in uranium miners and the workers in charge of ore processing and can represent the major route of excretion for the absorbed metal. Significant differences were shown between the uranium level in the urine of workers group and the control group

  11. Extraction of uranium low-grade ores from Great Divide Basin, Wyoming. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    Judd, J.C.; Nichols, I.L.; Huiatt, J.L.

    1983-04-01

    The US Bureau of Mines is investigating the leachability of carbonaceous uranium ore samples submitted by the DOE under an Interagency Agreement. Studies on eight samples from the Great Divide Basin, Wyoming, are the basis of this report. The uranium content of the eight ore samples ranged from 0.003 to 0.03% U 3 O 8 and contained 0.7 to 45% organic carbon. Experiments were performed to determine the feasibility of extracting uranium using acid leaching, roast-acid leaching and pressure leaching techniques. Acid leaching with 600 lb/ton H 2 SO 4 plus 10 lb/ton NaClO 3 for 18 h at 70 0 C extracted 65 to 83% of the uranium. One sample responded best to a roast-leach treatment. When roasting for 4 h at 500 0 C followed by acid leaching of the calcine using 600 lb/ton H 2 SO 4 , the uranium extraction was 82%. Two of the samples responded best to an oxidative pressure leach for 3 h at 200 0 C under a total pressure of 260 psig; uranium extractions were 78 and 82%

  12. The critical importance of pulp concentration on the flotation of galena from a low grade lead–zinc ore

    Directory of Open Access Journals (Sweden)

    Xianping Luo

    2016-04-01

    Full Text Available The Qixia orebody is a complex lead–zinc sulfide system with pyrite gangue and minor amounts of copper. In order to improve the flotation results, laboratory scale flotation testing of ore samples taken from this operation was performed. Flotation tests used a sequential recovery protocol for selective flotation of first the lead and thereafter the zinc. The key parameters that influence flotation performance of lead mineral were tested in this paper. The test data show that, for comparable collector, grinding time, flotation pH and solid-in-pulp concentration, the increase of solid-in-pulp concentration has the most significant effect on the recovery and selective separation of lead mineral. The increase of solid-in-pulp concentration from 27% to 55% makes the recovery of lead mineral increased from 60% to 80% and the lead grade increased from 27.5% to 29.1%.

  13. Experimental study on bio-leaching of high sulphuric acid consumption uranium ore by adding sulphide

    International Nuclear Information System (INIS)

    Meng Yunsheng; Zheng Ying; Liu Hui; Cheng Hao; Zhou Lei; Liu Chao; Fan Baotuan; Li Jianhua

    2012-01-01

    In order to decrease acid consumption and increase leaching rate, an experiment on bio-leach-ing of low grade uranium ore by adding sulphide was done. Compared with conventional leaching method, the leaching rate of uranium is improved by 3% and the leaching period was reduced to 60 days from 90 days by bio-leaching method of adding sulphide. In order to decrease acid consumption with bio-leaching by adding sulphide obviously, robust bacteria to sulphide should be chosen. (authors)

  14. Recovery of uranium low grade ores by froth flotation: study of the texture and synergetic effects of flotation reagents

    International Nuclear Information System (INIS)

    Duverger, Agathe

    2013-01-01

    Due to the energy growing demand, uranium low grade ores may be those exploited in the future. Uranium ores conventional treatment does not often use mineral processing such as concentration methods for reducing leaching reagent consumption. The aim of this work is to develop an upgrading process to improve the operating process (alkaline heap leaching) taking into account the mineralogical and textural variability of the ore. The Trekkopje deposit is composed of calcrete and a gypscrete. The uranium bearing mineral is carnotite (K 2 (UO 2 ) 2 [VO 4 ] 2 .3H 2 O). The gangue minerals are composed by silicates, such as quartz, feldspars, micas and Ca-minerals, calcite and gypsum (XRD and ICP-MS analysis). A SEM image processing was used to study the textural properties and the exposed free surface of mineral inclusions in clay clusters. In calcrete milled to -200 μm, 50 % of all carnotite is associated with clay clusters, which are composed by 98 % of palygorskite, 2 % of illite, montmorillonite, and interbedded clays (XRD and microprobe analysis). The carnotite grain size is 95 % less than 70 μm. Calcite is the main inclusion in clay clusters. Indeed, the calcite inclusions average rate in the clay clusters is 12 % and 5 % for carnotite inclusion. And the free exposed surface percentage of these minerals in clay clusters is 3 % and 6 %, thus indicating that the inclusions should not affect the behavior of mixed clay particles. However, ore flotation essays did not verify this hypothesis. Three minerals separation have been proposed based on the mineral ability to consume leaching reagents: separating Ca-minerals from silicates, palygorskite from gangue minerals and carnotite from gangue minerals. A study of silicates and Ca-minerals electrokinetic properties (electrophoresis) was carried out to select the collectors and the optimum pH range for selective flotation. Basic pH near neutral was proved to be optimal for the separation of gangue minerals with cationic

  15. Geodynamic condition of formation of favorable structural positions for ore-grade gold placement in auminzatau-beltau ore area (the central kyzyl kum, western uzbekistan)

    Science.gov (United States)

    Janibekov, Bobir Omonovich; Turapov, M. K.

    2017-09-01

    Work is directed on studying of a geodynamic condition under which the structural positions controlling process of endogenous ore formation were formed. It is shown that explosive region tectonics under the influence of regional tectonic efforts formed structural elements (positions) which controlled formation of gold deposits. It is recognized that structural positions are defined by variety of systems of disjunctive dislocation and their relationship among themselves. Formation of favorable positions depends as well on morphology of ore controlling structures, on degree of their tectonic activity and spatial situation in relation to the direction of tectonic (geodynamic) efforts.

  16. Ore grade manganese nodules from the central Indian basin: an evaluation

    Digital Repository Service at National Institute of Oceanography (India)

    Sudhakar, M.

    Comparative studies on manganese nodules from two different areas (S and R) in the Central Indian Basin show distinct variations in their composition, grade (percent Ni + Cu), and abundance (kg/m2), which are explained in terms of various genetic...

  17. Development of the heap leaching of low-grade uranium ores for conditions of OJSC Priargunsky Mining and Chemical plant (PPGKhO)

    International Nuclear Information System (INIS)

    Morozov, A.; Litvinenko, V.

    2014-01-01

    The treatment of low-grade commercial uranium ores by heap leaching has been carried out at the enterprise since 1996. During the initial stage of development, the ore piles were formed of the raw ore having the run-of-mine coarseness with uranium content around 0.08%. Under such conditions, recovery of the metal to the solution is 60-65% in case of a pile treatment lasting 2 years. To intensify the process and to provide a stable concentration of uranium in the productive solutions transferred to sorption, the enterprise developed and implemented a method of percolation leaching of low-grade ores with re-circulation of productive solutions through the re-treated ore bulk (RF patent No. 2226564). The main peculiarity of such leaching is simultaneous moistening of the ore by productive solutions and by barren solutions that are sharpened with sulphuric acid; that gives the possibility to wet far bigger areas of piles under constant volume of productive solutions outputting to the sorption treatment. Such scheme enables to treat successively first the piles at the “re-treatment” (where the metal is mainly extracted), and then the piles at the “active leaching” stage (where the metal is mainly inside the ore bulk). The technical and economic indexes of the heap leaching of low-grade uranium ores were significantly increased in 2006, when the X-ray-radiometric treatment plant was commissioned. The technological scheme of ore treatment at the processing plant includes mould and grating of the raw material with delivery of undersized products enriched with uranium: -5 mm are transferred to the pulp process; fractions (-200+40) mm to the X-ray-radiometric separation; the material of size (-40+5) mm, washed-out from clayey and fine particles, are sent to the uranium heap leaching in piles. Delivery of the ore material having size (-40+5) mm to treatment by the acid leaching method excluded colmatage and creation of zones impermeable for water, and in combination

  18. Development of the Method of Bacterial Leaching of Metals out of Low-Grade Ores, Rocks, and Industrial Wastes Using Neutron Activation Analysis

    CERN Document Server

    Tsertsvadze, L A; Petriashvili, Sh G; Chutkerashvili, D G; Kirkesali, E I; Frontasyeva, M V; Pavlov, S S; Gundorina, S F

    2001-01-01

    The results of preliminary investigations aimed at the development of an economical and easy to apply technique of bacterial leaching of rare and valuable metals out of low-grade ores, complex composition ores, rocks, and industrial wastes in Georgia are discussed. The main groups of microbiological community of the peat suspension used in the experiments of bacterial leaching are investigated and the activity of particular microorganisms in the leaching of probes with different mineral compositions is assessed. The element composition of the primary and processed samples was investigated by the epithermal neutron activation analysis method and the enrichment/subtraction level is estimated for various elements. The efficiency of the developed technique to purify wastes, extract some scrace metals, and enrich ores or rocks in some elements, e.g. Au, U, Th, Cs, Sr, Rb, Sc, Zr, Hf, Ta, Gd, Er, Lu, Ce, etc., is demonstrated.

  19. Biohydrometallurgy and membrane technology for resource recovery from low-grade ores and mining residuals; Biohydrometallurgie und Membrantechnik zur Wertstoffgewinnung aus Armerzlagerstaetten und bergbaulichen Altablagerungen

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Arite; Meschke, Katja; Bohlke, Kevin; Haseneder, Roland [TU Bergakademie Freiberg (Germany). Inst. fuer Thermische Verfahrenstechnik, Umwelt-, Naturstoffverfahrenstechnik (ITUN); Daus, Birgit [Helmholtz-Zentrum fuer Umweltforschung GmbH - UFZ, Leipzig (Germany). Dept. Analytik; Repke, Jens-Uwe [Technische Univ. Berlin (Germany). FG Dynamik und Betrieb Technischer Anlagen

    2017-02-15

    The recovery of strategic elements from secondary mineral resources and low grade ores is of increasing relevance, due to a changing global market as well as for reasons of sustainability. The present article shows the potential of biohydrometallurgy as an efficient technology for mobilization of metals from secondary mineral resources. Furthermore, the application of membrane separation as a successful technique for the recovery of metals from bioleaching solutions is presented. These issues are discussed within the scope of recent research projects.

  20. XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

    International Nuclear Information System (INIS)

    Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

    2015-01-01

    Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases

  1. High temperature attack of ores by a liquor containing essentially a soluble bicarbonate

    International Nuclear Information System (INIS)

    Maurel, Pierre; Nicolas, Francois; Bosca, Bernard.

    1978-01-01

    New process for high temperature oxidizing digestion of ores containing at least one metal in the uranium, vanadium and molybdenum group, by an aqueous liquor containing sodium bicarbonate and sodium carbonate in the presence of free oxygen insufflated into the reaction medium [fr

  2. Extraction of lithium Carbonate from Petalite Ore (Momeik District, Myanmar)

    International Nuclear Information System (INIS)

    Tun Tun Moe

    2011-12-01

    The methods for preparing high purity lithium carbonate which can be used for pharmaceutical applications, electronic grade crystals of lithium or to prepare battery-grade lithium metal are disclosed. Lithium carbonate as commercially produced from mineral extraction, lithium containing brines or sea water. One method for the production of pure lithium carbonate from mineral source (petalite ore) obtained from Momeik District, Myanmar is disclosed. Method for mineral processing of ore concentrate is also disclosed.

  3. Research on the possibility of concentrating low-grade uranium ores by bacterial leaching. Part of a coordinated programme on the bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Tataru, S.

    1978-12-01

    Effect of extraction reagents with solvents on the bacteria and the influence of eluants on the bacteria development was studied. To establish the effects of various solvents and eluants on the development of bacteria, on oxidizing capacity of Fe 2+ to Fe 3+ , and to study their influence on bacteria morphology, bacteria strains were contacted with Alamine 336, trioctylamine, LIX and nitric eluant. Bacteria development and the oxidizing ability of Fe 2+ to Fe 3+ were significantly inhibited and morphological changes of individuals in the bacteria population were found. The bacteria populations resulted from ores had a more decreased resistance as the bacteria culture was better selected by repeated inoculations and incubations. In case of the bacterial leaching in heap or in situ a periodical extraction with solvents is required in order to allow the bacteria population between successive extraction stage be remade

  4. Optimization of staged bioleaching of low-grade chalcopyrite ore in the presence and absence of chloride in the irrigating lixiviant: ANFIS simulation.

    Science.gov (United States)

    Vakylabad, Ali Behrad; Schaffie, Mahin; Naseri, Ali; Ranjbar, Mohammad; Manafi, Zahra

    2016-07-01

    In this investigation, copper was bioleached from a low-grade chalcopyrite ore using a chloride-containing lixiviant. In this regard, firstly, the composition of the bacterial culture media was designed to control the cost in commercial application. The bacterial culture used in this process was acclimated to the presence of chloride in the lixiviant. Practically speaking, the modified culture helped the bio-heap-leaching system operate in the chloridic media. Compared to the copper recovery from the low-grade chalcopyrite by bioleaching in the absence of chloride, bioleaching in the presence of chloride resulted in improved copper recovery. The composition of the lixiviant used in this study was a modification with respect to the basal salts in 9 K medium to optimize the leaching process. When leaching the ore in columns, 76.81 % Cu (based on solid residues of bioleaching operation) was recovered by staged leaching with lixiviant containing 34.22 mM NaCl. The quantitative findings were supported by SEM/EDS observations, X-ray elemental mapping, and mineralogical analysis of the ore before and after leaching. Finally, Adaptive neuro-fuzzy inference system (ANFIS) was used to simulate the operational parameters affecting the bioleaching operation in chloride-sulfate system.

  5. The effects of mixtures of potassium amyl xanthate (PAX and isopropyl ethyl thionocarbamate (IPETC collectors on grade and recovery in the froth flotation of a nickel sulfide ore

    Directory of Open Access Journals (Sweden)

    Westhein Maree

    2017-12-01

    Full Text Available Potassium amyl xanthate (PAX and sodium isobutyl xanthate (SIBX are commonly used collectors in both the bulk and selective froth flotation of sulfide ores. These thiol xanthate collectors are conventionally mixed together as well as with more selective thiol collectors such as dithiophosphates (DTP and dithiocarbamates (DTC, in order to improve selectivity. With deteriorating nickel sulfide ores, more selective collectors and collector mixtures are desired for the efficient extraction of nickel. Thionocarbamates (TC are another group of thiol collectors used for selective froth flotation of sulfide minerals. Thionocarbamates are especially used in the selective froth flotation of chalcopyrite over pyrite and galena, but little is known about its selectivity with regards to nickel. Thionocarbamates are also more stable over larger pH ranges in comparison to xanthates and they possess beneficial frothing properties. This study compared the effects of using potassium amyl xanthate (PAX, isopropyl ethyl thionocarbamate (IPETC, sodium isobutyl xanthate (SIBX and their mixtures in the froth flotation of a pentlandite ore. In the mixtures of PAX or SIBX with IPETC, the xanthate accounted for 95.5 mol% and for the PAX and SIBX mixture a 50:50 mixture was used. This study showed that the highest cumulative nickel grades were obtained with PAX, SIBX and there mixture. The highest cumulative nickel recoveries were obtained with IPETC and its mixtures with PAX and SIBX (50–62%. Keywords: Nickel sulfide, Xanthate, Thionocarbamate, Grade, Recovery

  6. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  7. Synthesis and characterization of highly purified nanosilica from pyrophyllite ores

    Energy Technology Data Exchange (ETDEWEB)

    Fuad, Abdulloh, E-mail: abdulloh.fuad.fmipa@um.ac.id; Mufti, Nandang; Diantoro, Markus; Subakti,; Septa Kurniawati, S. [Jurusan Fisika FMIPA Universitas Negeri Malang. Jl. Semarang No. 5 Malang, east Java (Indonesia)

    2016-03-11

    A simple method based on alkaline extraction followed by acid precipitation and acid dissolution has been developed to produce highly purified nanosilica from pyrophyllite materials. The reaction parameters such as molar ratio NaOH/SiO{sub 2}, reaction time and reaction temperature are varied for obtaining maximum nanosilica convertion. About 99,45% highly purified precipitated nanosilica measure with ICP, 259 m{sup 2}/gr measure with BET surface area, 97% whiteness and 3 ml/gr oil absorbtion from pyrophyllite materials has been achieved in closed system at 150°C within 180 min. The physicals and chemical properties (such as X-Ray Diffraction from PANalytical, X-Ray Fluorescence Minipal4 from PANanalytical, BET surface area, Forier Transform Infra Red Spectroscopy from Hitachi, and SEM-EDS Inspect-S50 from FEI Company) of the highly purity nanosilica were studied.

  8. Mining and processing of uranium ores in the USSR

    International Nuclear Information System (INIS)

    Laskorin, B.N.; Mamilov, V.A.; Korejsho, Yu.A.

    1983-01-01

    Experience gained in uranium ore mining by modern methods in combination with underground and heap leaching is summarized. More intensive processing of low-grade ores has been achieved through the use of autoclave leaching, sorptive treatment of thick pulps, extractive separation of pure uranium compounds, automated continuous sorption devices of high efficiency for processing the underground- and heap-leaching liquors, natural and mine water, and recovery of molybdenum, vanadium, scandium, rare earths and phosphate fertilizers from low-grade ores. Production of ion-exchangers and extractants has been developed and processes for concomitant recovery of copper, gold, ionium, tungsten, caesium, zirconium, tantalum, nickel and cobalt have been designed. (author)

  9. Ore sorting using natural gamma radiation

    International Nuclear Information System (INIS)

    Clark, G.J.; Dickson, B.L.; Gray, F.E.

    1980-01-01

    A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

  10. XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

    Energy Technology Data Exchange (ETDEWEB)

    Omran, Mamdouh, E-mail: mamdouh.omran@oulu.fi [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); Fabritius, Timo [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A. [Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); El-Aref, Mortada; Elmanawi, Abd El-Hamid [Geology Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2015-08-01

    Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe{sub 2}O{sub 3} and P{sub 2}O{sub 5} contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe{sup 3+}) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases.

  11. High temperature chlorination of uranium and some radionuclides from rich sulphide ores

    International Nuclear Information System (INIS)

    Mahdy, M.A.

    1992-01-01

    This work is concerned with the application of the high temperature chlorination technique upon a sulphide-rich uranium ore from elliot lake, ontario, canada. The purpose is to find a substitute to conventional sulphuric acid leaching which involves both acid drainage and radionuclide dissolution problems. Test work has therefore been directed towards studying some relevant factors of chlorination beside the effect of a number of additives

  12. A Review on New Technological Progress for Beneficiation of Refractory Phosphate Ore in China

    Science.gov (United States)

    Dong, Xu; Siqing, Liu; Yanqing, Yao; Hailin, Liu; Yi, Pei

    2017-05-01

    The world is rich in phosphate resources, but the vast majority of the resources are of middle and low grade ores, and it is difficult to obtain high grade concentrate at a high recovery by using traditional separation methods. In this paper, the distribution and flotation processes of typical phosphate ores in China are introduced. Considering the current situation in phosphate ore beneficiation both home and abroad, the new trend of processing technology and reagents in China are summarized. Flotation is still regarded as the main processing method in phosphate ore beneficiation for a certain time in near future.

  13. Chlorine/chloride based processes for uranium ores

    International Nuclear Information System (INIS)

    1980-11-01

    The CE Lummus Minerals Division was commissioned by The Department of Supply and Services to develop order-of-magnitude capital and operating cost estimates for chlorine/chloride-based processes for uranium ores. The processes are designed to remove substantially all radioactive consituents from the ores to render the waste products harmless. Two processes were selected, one for a typical low grade ore (2 lb. U 3 O 8 /ton ore) and one for a high grade ore (50 lbs U 3 O 8 /ton). For the low grade ore a hydrochloric acid leaching process was chosen. For high grade ore, a more complex process, including gaseous chlorination, was selected. Capital cost estimates were compiled from information obtained from vendors for the specified equipment. Building cost estimates and the piping, electrical and instrumentation costs were developed from the plant layout. Utility diagrams and mass balances were used for estimating utilities and consumables. Detailed descriptions of the bases for capital and operating cost estimates are given

  14. Status report from USSR [Processing of Low-Grade Uranium Ores]; Doklad o sostoyanii voprosa v SSSR

    Energy Technology Data Exchange (ETDEWEB)

    Zefirov, A P [Gosudarstvennyj Komitet Po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1967-06-15

    The uranium industry for processing poor uranium ores in the USSR was established in recent years. As a result of research work institutions and enterprises in the development of this industry was provided by rapid technological advances that allowed dramatically increased productivity, reduced consumption of reagents, simplified process flow diagrams, and reduced production costs. At present, the basis for uranium industry, including and poor uranium ore deposits in the USSR are with different content valuable components (uranium, phosphorus, molybdenum, rare earth elements, thorium, iron, .. .)

  15. Distribution of uranium in two sulphide ore environments from the reversed metamorphic sequence of the Daling Rocks in the Dargeeling-Sikkim Himalaya, India

    International Nuclear Information System (INIS)

    Ghosh, A.K.

    1988-01-01

    In the low-grade Daling metasediments of Gorubathan, the average U content of 3-4 ppm reflects the original U content of the unmetamorphosed sediments. The high-grade metasediments of Dichu averag 6 ppm, and the sulphide ores of this area also have more U compared to Gorubathan ores.This higher U content in the high-grade rocks and in the associated ores is believed to be the result of enrichment during metasomatic activity in the area. Neverthelessthe fact that the Daling metasediments have higher U contents thanthat of the sulphide ores appears to be independent of the grade of metamorphism in the progressive sequence

  16. Sedimentary exhalative nickel-molybdenum ores in south China

    Science.gov (United States)

    Lott, D.A.; Coveney, R.M.; Murowchick, J.B.; Grauch, R.I.

    1999-01-01

    Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

  17. Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

    International Nuclear Information System (INIS)

    Corrans, I.J.; Levin, J.

    1979-01-01

    Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20μm. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed [af

  18. Preconcentration of low grade uranium ores by gravity and magnetic methods: a case study with copper tailings from Singhbhum, Bihar, India

    International Nuclear Information System (INIS)

    Natarajan, R.; Sreenivas, T.; Krishna Rao, N.

    1992-01-01

    The physical beneficiation methods applied to uranium ores are gravity and magnetic techniques. Feasibility of application of these two techniques has been industrially demonstrated in the case of Palabora copper-uranium ores and Witwatersrand gold-uranium ores respectively. In India exhaustive studies have been carried out on the application of gravity and magnetic methods for preconcentration of uranium values from tailings of copper plants at Surda, Rakha and Mosabani in Singhbhum. While recovery by shaking tables is poor owing to non-liberation and inefficient recovery in finer particle sizes (-37μm), gravity machines like Bartles Mozely Separator and Bartles Cross Belt Concentrator are able to give improved recovery in sizes down to about 15μm. Application of Wet High Intensity Magnetic Separator (WHIMS) is able to improve the recovery to about 75 to 85% from the three tailings, and the improvement is due to the ability of WHIMS collect the micaceous mineral particles containing composite uranium values, as well as uraninite particles down to about 10μm in size. WHIMS is inefficient in recovering uraninite particles below 5μm. High Gradient Magnetic Separator and Super Conducting High Gradient Magnetic Separator, on the other hand, are able to give enhanced recovery of even < 5μm uraninite particles. With the improved technology of gravity and magnetic methods now available, it should now be techno-economically feasible to employ preconcentration of low tenor uranium ores by physical beneficiation, prior to chemical processing. (author). 25 refs. 8 figs, 5 tabs

  19. A High Performance Lithium-Ion Capacitor with Both Electrodes Prepared from Sri Lanka Graphite Ore.

    Science.gov (United States)

    Gao, Xiaoyu; Zhan, Changzhen; Yu, Xiaoliang; Liang, Qinghua; Lv, Ruitao; Gai, Guosheng; Shen, Wanci; Kang, Feiyu; Huang, Zheng-Hong

    2017-04-14

    The natural Sri Lanka graphite (vein graphite) is widely-used as anode material for lithium-ion batteries (LIBs), due to its high crystallinity and low cost. In this work, graphitic porous carbon (GPC) and high-purity vein graphite (PVG) were prepared from Sri Lanka graphite ore by KOH activation, and high temperature purification, respectively. Furthermore, a lithium-ion capacitor (LIC) is fabricated with GPC as cathode, and PVG as anode. The assembled GPC//PVG LIC shows a notable electrochemical performance with a maximum energy density of 86 W·h·kg -1 at 150 W·kg -1 , and 48 W·h·kg -1 at a high-power density of 7.4 kW·kg -1 . This high-performance LIC based on PVG and GPC is believed to be promising for practical applications, due to its low-cost raw materials and industrially feasible production.

  20. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.

    Science.gov (United States)

    Zakrzewska-Koltuniewicz, Grażyna; Herdzik-Koniecko, Irena; Cojocaru, Corneliu; Chajduk, Ewelina

    2014-06-30

    The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. High grade magnesium from waste bittern

    International Nuclear Information System (INIS)

    El-Yamani, I.S.; Farah, M.Y.; Isaac, S.L.

    1979-01-01

    The production of high grade magnesia for nuclear purposes from sea water by use of both aqueous and gaseous ammonia has been described. The effect of precipitating conditions on the settling rate and magnesium recovery, was thoroughly examined. Ammonia gas approach was recommended and justified

  2. Studies on high grade cerebral gliomas

    International Nuclear Information System (INIS)

    Bleehen, N.M.

    1990-01-01

    A brief review of attempts in the United Kingdom to improve the results of treatment of high grade (grade 3, 4) supra-tentorial astrocytomas is presented. The radiosensitizer misonidazole failed to improve the results of post-surgical radiotherapy, however, multivariate analysis of data from these patients has provided a prognostic index of use in defining good and poor prognosis patients. An overview study of adjuvant nitrosourea therapy trials has shown a small significant advantage for the chemotherapy. A study of chemosensitization by benznidazole of CCNU treatment of patients in relapse failed to demonstrate any effect. 13 references

  3. Influence of a High-Pressure Comminution Technology on Concentrate Yields in Copper Ore Flotation Processes

    Directory of Open Access Journals (Sweden)

    Saramak D.

    2014-10-01

    Full Text Available The article concerns the issues of flotation process effectiveness in relationship to the operating conditions of a high-pressure comminution process course. Experimental programme covering a flotation laboratory batch tests was a verification technique of a high-pressure crushing operations course. The most favorable values of flotation concentrate weight recoveries were obtained for the pressing force 6 kN and 4% of the feed moisture. It was also determined the model of the concentrate weight recovery as a function of pressing force in the press and feed moisture content. This model was the basis for the optimization of effects of copper ore flotation processes preceded in high-pressure crushing operation in roller presses.

  4. Gangue minerals reactivity in oxidative leaching of uraninite with dilute sulfuric acid from low-grade ores. An approach for better leach liquor purity

    International Nuclear Information System (INIS)

    Madakkaruppan, V.; Chanchal Sarbajna; Pius, Anitha; Sreenivas, T.

    2016-01-01

    This paper presents results of sulfuric acid leaching studies carried out on a low-grade uranium ore with emphasis on attaining maximum uranium leachability with minimum content of detrimental ions like Si, Al, Fe, Mg and P, which originate from reactive gangue minerals like chlorite, biotite and apatite. A 'two-stage leaching' scheme was developed wherein the total reaction time and the pH of the slurry were split such that the initial phase consists of higher acidity with shorter reaction period and the later phase involves reduced acidity and longer reaction time. This modification gives leach liquor of higher purity with good uranium leachability at relatively lower acid consumption. (author)

  5. Mineralogical and geochemical characterization of supergene Cu-Pb-Zn-V ores in the Oriental High Atlas, Morocco

    Science.gov (United States)

    Verhaert, Michèle; Bernard, Alain; Dekoninck, Augustin; Lafforgue, Ludovic; Saddiqi, Omar; Yans, Johan

    2017-10-01

    In the Moroccan High Atlas, two sulfide deposits hosted by Jurassic dolostones underwent significant weathering. In the Cu deposit of Jbel Klakh, several stages of supergene mineralization are distinguished: (1) the replacement of hypogene sulfides in the protolith (chalcopyrite) by secondary sulfides in the cementation zone (bornite, digenite, chalcocite, covellite), (2) the formation of oxidized minerals in the saprolite (malachite, azurite, brochantite) where the environment becomes more oxidizing and neutral, and (3) the precipitation of late carbonates (calcite) and iron (hydr-)oxides in the laterite. The precipitation of carbonates is related to the dissolution of dolomitic host rocks, which buffers the fluid acidity due to the oxidation of sulfides. In the Jbel Haouanit Pb-Zn deposit, the mineral assemblage is dominated by typical calamine minerals, Cu minerals (chalcocite, covellite, malachite), and a Cu-Pb-Zn vanadate (mottramite). Galena is successively weathered in anglesite and cerussite. Sphalerite is weathered in smithsonite, which is rapidly replaced by hydrozincite. Late iron (hydr-)oxides are mainly found at the top of both deposits (laterite). Both deposits are thus characterized by specific mineral zoning, from laterite to protolith, related to variations in the mineralogy and ore grades and probably caused by varying Eh-pH conditions.

  6. Laboratory studies on leaching of low grade uranium ores and treatment of low level liquid waste generated by leaching experiments

    International Nuclear Information System (INIS)

    Palabrica, O.T.; Antonino, E.J.; Caluag, L.A.; Villamater, D.

    1980-07-01

    Acid leaching experiments of preconcentrated uranium ore were carried out at a pulp density of 50% solids, using sulfuric acid with sodium chlorate as oxidant. The different leaching parameters considered in this work were temperature, oxidant level and leaching time. In the experimental procedure, the concentration of oxidant and the temperature were varied to determine how they affect the leaching process. Experimental results are illustrated in tabulated form for better interpretation. Uranium analyses were done by fluorimetric and delayed-neutron activation analysis. An anion exchange method using Dowex 1 x 8, 200-400 mesh (Cl - ) was used in treating the low-level liquid waste generated by leaching experiments. The purpose of this treatment was to minimize radioactive contamination in the waste materials and also to recover some of the uranium left in the liquid waste. (author)

  7. High grade glioma: Imaging combined with pathological grade defines management and predicts prognosis

    International Nuclear Information System (INIS)

    Burnet, Neil G.; Lynch, Andrew G.; Jefferies, Sarah J.; Price, Stephen J.; Jones, Phil H.; Antoun, Nagui M.; Xuereb, John H.; Pohl, Ute

    2007-01-01

    Introduction: There is ambiguity in pathological grading of high grade gliomas within the WHO 2000 classification, especially those with predominant oligodendroglial differentiation. Patients and methods: All adult high grade gliomas treated radically, 1996-2005, were assessed. Cases in which pathology was grade III but radiology suggested glioblastoma (GBM) were classified as 'grade III/IV'; their pathology was reviewed. Results: Data from 245 patients (52 grade III, 18 grade III/IV, 175 GBM) were analysed using a Cox Proportional Hazards model. On pathology review, features suggestive of more aggressive behaviour were found in all 18 grade III/IV tumours. Oligodendroglial components with both necrosis and microvascular proliferation were present in 7. MIB-1 counts for the last 8 were all above 14%, mean 27%. Median survivals were: grade III 34 months, grade III/IV 10 months, GBM 11 months. Survival was not significantly different between grade III/IV and GBM. Patients with grade III/IV tumours had significantly worse outcome than grade III, with a hazard of death 3.7 times higher. Conclusions: The results highlight the current inconsistency in pathological grading of high grade tumours, especially those with oligodendroglial elements. Patients with histological grade III tumours but radiological appearances suggestive of GBM should be managed as glioblastoma

  8. Economic evaluation of preconcentration of uranium ores

    International Nuclear Information System (INIS)

    1981-04-01

    The economics of two options for the preconcentration of low-grade uranium ores prior to hydrochloric acid leaching were studied. The first option uses flotation followed by wet high-intensity magnetic separation. The second option omits the flotation step. In each case it was assumed that most of the pyrite in the ore would be recovered by froth flotation, dewatered, and roasted to produce sulphuric acid and a calcine suitable for acid leaching. Savings in operating costs from preconcentration are offset by the value of uranium losses. However, a capital saving of approximately 6 million dollars is indicated for each preconcentration option. As a result of the capital saving, preconcentration appears to be economically attractive when combined with hydrochloric acid leaching. There appears to be no economic advantage to preconcentration in combination with sulphuric acid leaching of the ore

  9. Discussion on uranium ore-formation age in Xiazhuang ore-field, northern Guangdong

    International Nuclear Information System (INIS)

    Wu Lieqin; Tan Zhengzhong; Liu Ruzhou; Huang Guolong

    2003-01-01

    There exist two genetic types of granite-type uranium deposits, i.e. the early-stage one, and the late-stage one. The early-stage uranium deposits are characterized by ore-formation ages of 122-138 Ma, and are high-grade uranium deposits of postmagmatic hydrothermal origin. The late-stage uranium deposits have ore-formation ages of 54-96 Ma. They mostly are low-grade uranium deposits, and of hydrothermal-regeneration origin with the uranium source derived from the mobilization of consolidated rocks. The early-stage uranium deposits should be the main target of further prospecting for high-grade uranium deposits in the region

  10. Work within the coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Jayaram, K.M.V.

    1978-10-01

    The paper relates geological and lithological aspects of host rocks to the leaching and precipitation of uranium through the agency of microorganisms. For this purpose three different host rocks were studied: a low grade uranium ore analysing 0.045% U 3 O 8 and two high grade ores analysing 0.27% and 1.8% U 3 O 8 respectively. The affect of ore composition, water composition and climatic conditions were studied in relation to the nature of the microflora indigenously developed

  11. Contemporary management of high-grade gliomas.

    Science.gov (United States)

    Sim, Hao-Wen; Morgan, Erin R; Mason, Warren P

    2018-01-01

    High-grade gliomas, including glioblastoma, are the most common malignant brain tumors in adults. Despite intensive efforts to develop new therapies for these diseases, treatment options remain limited and prognosis is poor. Recently, there have been important advances in our understanding of the molecular basis of glioma, leading to refinements in our diagnostic and management approach. There is new evidence to guide the treatment of elderly patients. A multitude of new agents have been investigated, including targeted therapies, immunotherapeutics and tumor-treating fields. This review summarizes the key findings from this research, and presents a perspective on future opportunities to advance the field.

  12. MRI differentiation of low-grade from high-grade appendicular chondrosarcoma

    International Nuclear Information System (INIS)

    Douis, Hassan; Singh, Leanne; Saifuddin, Asif

    2014-01-01

    To identify magnetic resonance imaging (MRI) features which differentiate low-grade chondral lesions (atypical cartilaginous tumours/grade 1 chondrosarcoma) from high-grade chondrosarcomas (grade 2, grade 3 and dedifferentiated chondrosarcoma) of the major long bones. We identified all patients treated for central atypical cartilaginous tumours and central chondrosarcoma of major long bones (humerus, femur, tibia) over a 13-year period. The MRI studies were assessed for the following features: bone marrow oedema, soft tissue oedema, bone expansion, cortical thickening, cortical destruction, active periostitis, soft tissue mass and tumour length. The MRI-features were compared with the histopathological tumour grading using univariate, multivariate logistic regression and receiver operating characteristic curve (ROC) analyses. One hundred and seventy-nine tumours were included in this retrospective study. There were 28 atypical cartilaginous tumours, 79 grade 1 chondrosarcomas, 36 grade 2 chondrosarcomas, 13 grade 3 chondrosarcomas and 23 dedifferentiated chondrosarcomas. Multivariate analysis demonstrated that bone expansion (P = 0.001), active periostitis (P = 0.001), soft tissue mass (P < 0.001) and tumour length (P < 0.001) were statistically significant differentiating factors between low-grade and high-grade chondral lesions with an area under the ROC curve of 0.956. On MRI, bone expansion, active periostitis, soft tissue mass and tumour length can reliably differentiate high-grade chondrosarcomas from low-grade chondral lesions of the major long bones. (orig.)

  13. MRI differentiation of low-grade from high-grade appendicular chondrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Douis, Hassan; Singh, Leanne; Saifuddin, Asif [The Royal National Orthopaedic Hospital NHS Trust, Department of Radiology, Stanmore, Middlesex (United Kingdom)

    2014-01-15

    To identify magnetic resonance imaging (MRI) features which differentiate low-grade chondral lesions (atypical cartilaginous tumours/grade 1 chondrosarcoma) from high-grade chondrosarcomas (grade 2, grade 3 and dedifferentiated chondrosarcoma) of the major long bones. We identified all patients treated for central atypical cartilaginous tumours and central chondrosarcoma of major long bones (humerus, femur, tibia) over a 13-year period. The MRI studies were assessed for the following features: bone marrow oedema, soft tissue oedema, bone expansion, cortical thickening, cortical destruction, active periostitis, soft tissue mass and tumour length. The MRI-features were compared with the histopathological tumour grading using univariate, multivariate logistic regression and receiver operating characteristic curve (ROC) analyses. One hundred and seventy-nine tumours were included in this retrospective study. There were 28 atypical cartilaginous tumours, 79 grade 1 chondrosarcomas, 36 grade 2 chondrosarcomas, 13 grade 3 chondrosarcomas and 23 dedifferentiated chondrosarcomas. Multivariate analysis demonstrated that bone expansion (P = 0.001), active periostitis (P = 0.001), soft tissue mass (P < 0.001) and tumour length (P < 0.001) were statistically significant differentiating factors between low-grade and high-grade chondral lesions with an area under the ROC curve of 0.956. On MRI, bone expansion, active periostitis, soft tissue mass and tumour length can reliably differentiate high-grade chondrosarcomas from low-grade chondral lesions of the major long bones. (orig.)

  14. Bacterial leaching of pyritic gold ores

    International Nuclear Information System (INIS)

    Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

    1998-01-01

    Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

  15. Aqueous-chlorine leaching of typical Canadian uranium ores

    International Nuclear Information System (INIS)

    Haque, K.E.

    1982-01-01

    Laboratory-scale aqueous-chlorine leaches were conducted on quartz-pebble conglomerates, pegmatite and vein-type ores. Optimum leach temperatures, pulp density and retention times were determined. Uranium extraction of 98 per cent was obtained from the Elliot Lake, Madawaska Mines of Bancroft and Rabbit Lake ores, 96 per cent from the Key Lake ore and 86 per cent from the Agnew Lake ore. However, tailings containing 15-20 pCi g -1 of radium-226 were obtained only from the Elliot Lake and Agnew lake quartz-pebble conglomerates and Bancroft pegmatite-type ores by second-stage leaches with HCl. The second-stage leach results indicate that multistage (3 or 4) acid-chloride or salt-chloride leaches might be effective to obtain tailings containing 15-20 pCi 226 Ra g -1 from the high-grade vein-type ores. Comparative reagent-cost estimates show that the sulphuric-acid leach process is far less expensive than aqueous chlorine leaching. Nevertheless, only the aqueous chlorine and acid-chloride leaches in stages are effective in producing tailings containing 15-20 pCi 226 Ra g -1 from the typical Canadian uranium ores. (Auth.)

  16. Ore sorting

    International Nuclear Information System (INIS)

    Hawkins, A.P.; Richards, A.W.

    1982-01-01

    In an ore sorting apparatus, ore particles are bombarded with neutrons in a chamber and sorted by detecting radiation emitted by isotopes of elements, such as gold, forming or contained in the particles, using detectors and selectively controlling fluid jets. The isotopes can be selectively recognised by their radiation characteristics. In an alternative embodiment, shorter life isotopes are formed by neutron bombardment and detection of radiation takes place immediately adjacent the region of bombardment

  17. High-grade primary pulmonary leiomyosarcoma

    Directory of Open Access Journals (Sweden)

    Rodrigo Afonso da Silva Sardenberg

    2011-12-01

    Full Text Available Primary sarcomas of the lung are rare and account for 0.5% of all primary lung tumors. There were approximately 300 cases described in the literature as of 2006. All histologic types of sarcoma were described, and the most common intrathoracic types reported were angiosarcoma, leiomyosarcoma, fibrosarcoma, hemangiopericytoma, and rhabdomyosarcoma. The biological behavior of these tumors is not well-known due to their low frequency. Leiomyosarcomas represent one of the most common subtypes encountered in the lungs, and usually occur during the sixth decade, with male predominance. Although the frequency of metastatic disease is not related to tumor size, prognosis was reported to be poorer in high-grade tumors. In comparison with other sarcomas, survival after complete resection of pulmonary leiomyosarcoma was reported as longer. We report on a patient with primary leiomyosarcoma originating from the bronchus with complete resection and long-term follow-up.

  18. Inhalation of uranium ores

    International Nuclear Information System (INIS)

    Stuart, B.O.; Jackson, P.O.

    1975-01-01

    In previous studies the biological dispositions of individual long-lived alpha members of the uranium chain ( 238 U, 234 U and 230 Th) were determined during and following repeated inhalation exposures of rats to pitchblende (26 percent U 3 O 8 ) ore. Although finely dispersed ore in secular equilibrium was inhaled, 230 Th/ 234 U radioactivity ratios in the lungs rose from 1.0 to 2.5 during 8 weeks of exposures and increased to 9.2 by four months after cessation of exposures. Marked non-equilibrium levels were also found in the tracheobronchial lymph nodes, kidneys, liver, and femur. Daily exposures of beagle dogs to high levels of this ore for 8 days resulted in lung 230 Th/ 234 U ratios of >2.0. Daily exposures of dogs to lower levels (0.1 mg/1) for 6 months, with sacrifice 15 months later, resulted in lung and thoracic lymph node 230 Th/ 234 U ratios ranging from 3.6 to 9 and nearly 7, respectively. The lungs of hamsters exposed to carnotite (4 percent U 3 O 8 ) ore in current lifespan studies show 230 Th/ 234 U ratios as high as 2.0 during daily inhalation of this ore in secular equilibrium. Beagle dogs sacrificed after several years of daily inhalations of the same carnotite ore plus radon daughters also showed marked non-equilibrium ratios of 230 Th/ 234 U, ranging from 5.6 to 7.4 in lungs and 6.2 to 9.1 in thoracic lymph nodes. This pattern of higher retention of 230 Th than 234 U in lungs, thoracic lymph nodes, and other tissues is thus consistent for two types of uranium ore among several species and suggests a reevaluation of maximum permissible air concentrations of ore, currently based only on uranium content

  19. Uranium ores

    International Nuclear Information System (INIS)

    Poty, B.; Roux, J.

    1998-01-01

    The processing of uranium ores for uranium extraction and concentration is not much different than the processing of other metallic ores. However, thanks to its radioactive property, the prospecting of uranium ores can be performed using geophysical methods. Surface and sub-surface detection methods are a combination of radioactive measurement methods (radium, radon etc..) and classical mining and petroleum prospecting methods. Worldwide uranium prospecting has been more or less active during the last 50 years, but the rise of raw material and energy prices between 1970 and 1980 has incited several countries to develop their nuclear industry in order to diversify their resources and improve their energy independence. The result is a considerable increase of nuclear fuels demand between 1980 and 1990. This paper describes successively: the uranium prospecting methods (direct, indirect and methodology), the uranium deposits (economical definition, uranium ores, and deposits), the exploitation of uranium ores (use of radioactivity, radioprotection, effluents), the worldwide uranium resources (definition of the different categories and present day state of worldwide resources). (J.S.)

  20. High Performance Graded Index Polymer Optical Fibers

    National Research Council Canada - National Science Library

    Garito, Anthony

    1998-01-01

    ...) plastic optical fibers (POF) and graded index (GI) POFs are reported. A set of criteria and analyses of physical parameters are developed in context to the major issues of POF applications in short-distance communication systems...

  1. Underground leaching - A method for the economic extraction of uranium from low-grade ores; Podzemnoe vyshchelachivanie - sposob ehkonomicheskogo izvlecheniya urana iz bednykh rud

    Energy Technology Data Exchange (ETDEWEB)

    Zefirov, A P [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj EHnergii SSSR, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1967-06-15

    The method of underground leaching of uranium ores has a number of advantages over extraction followed by processing of the ores in factories. It has been studied in two types of deposit, occurring in rock masses and sandy shales. Research techniques were worked out accordingly for the leaching of uranium from large-grained ore (-200 mm) and from layers in natural stratification. Special models were constructed permitting the simulation of underground leaching conditions. The results obtained were checked in field conditions on experimental plots and experimental underground blocks. The investigations demonstrated the practicability of the process of underground leaching of uranium from certain ores and made it possible to work out flow-sheets and routines for an industrial process, information about which is given in the paper. (author)

  2. Obtention of high purity silica from the flotation waste of itabiritic ore

    International Nuclear Information System (INIS)

    Martins, Polyana Fabricia Fernandes

    2016-01-01

    Banded iron formations are exploited as iron mineral in 'Quadrilatero Ferrifero' of Minas Gerais (MG) State, Brazil. About half of the amount of extracted material becomes tailings, which are stored in tailing dams or used for filling mining pits. Tens of thousands of tons are generated daily in operating mines in this region, causing concern about the environmental liabilities, and costs to manage the tailing dams. Miners are committed to finding uses for these wastes in other productive chains. This thesis aimed to obtain high purity silica from the flotation tailings of banded iron formations using classical techniques for ore processing, such as particle size classification and magnetic separation, followed by hydrometallurgical leaching, also alkaline fusion and chemical precipitation. The tailings samples was collected in the tailings dam of Peak Mine operated by Vale A.S., in Itabirito – MG. This sample had initially 33.4% by weight SiO 2 , 57.4% wt Fe 2 O 3 and 8.31% wt Al 2 O 3 . After desliming for disposal of the fine particles (-37μm) the composition was 68.0% SiO 2 , 31.4% Fe 2 O 3 and 0.50% Al 2 O 3 . After magnetic separation, the composition was 93.8% SiO 2 , 1.16% Fe 2 O 3 and 3.80% Al 2 O 3 . After acid leaching l or digestion to remove impurities, it was possible to obtain silica with 98% purity. The fusion with sodium hydroxide, followed by alkaline leaching of sodium silicate and silica precipitation gave purities of about 99.5%. Values even higher may be possible with optimization of the parameters of alkaline fusion or by repeating the process from the product with purity of 99.5%. The iron oxide content and the aluminum main contaminants were 0.01% and 0.07%, respectively. Amorphous silica was obtained with high specific surface (322 m 2 /g) and particle size less than 200 nm. Depending on the application, a control should be made for the impurities, such as phosphorus, potassium and boron. (author)

  3. Multiparametric Magnetic Resonance Imaging for Discriminating Low-Grade From High-Grade Prostate Cancer

    NARCIS (Netherlands)

    Vos, E.K.; Kobus, T.; Litjens, G.J.S.; Hambrock, T.; Hulsbergen-van de Kaa, C.A.; Barentsz, J.O.; Maas, M.C.; Scheenen, T.W.J.

    2015-01-01

    The aim of this study was to determine and validate the optimal combination of parameters derived from 3-T diffusion-weighted imaging, dynamic contrast-enhanced imaging, and magnetic resonance (MR) spectroscopic imaging for discriminating low-grade from high-grade prostate cancer (PCa).The study was

  4. Exploitation study of the ore-body ''Tigre III''. Open-cut design and study of high-recovery underground mining method for the Tigre III ore-body

    International Nuclear Information System (INIS)

    Baluszka, J.C.

    1980-01-01

    The paper first carries out an analysis for the purpose of determining the limiting sterile/ore ratio for open-cut and underground mining in the specific filling case of Tigre III. In this connection it considers a high-recovery method of underground mining (involving the use of cemented hydropneumatic chambers), a general mine plan covering access, transport, ventilation and removal of ore as well as auxiliary services relating to the Tigre III ore body as a whole. The costs of this method of mining are determined for purposes of comparison with the open-cut method. Similarly, the limiting sterile/ore ratio is taken as the basis for an analysis of different types of pit and a design suited to the limiting ratio is adopted. As a final solution the paper favours a method which combines open-cut and underground mining. It proposes the use of the open-cut method up to the limiting ratio (in accordance with the pit design chosen) and of underground method (by the filling chamber method) for the rest of the area. (author)

  5. Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen

    Science.gov (United States)

    Elliott, R.; Pickles, C. A.

    2017-09-01

    Nickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673-873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

  6. Synthesis of high purity rutile nanoparticles from medium-grade Egyptian natural ilmenite

    Directory of Open Access Journals (Sweden)

    Mohamed G. Shahien

    2015-09-01

    Full Text Available The Egyptian magmatic ilmenite is classified as a medium-grade ore. The present work is an attempt to produce a high-quality TiO2 that can be used in several industries from this medium-grade raw material using the mechanical activation, carbothermic reduction, hydrochloric acid leaching and calcination. A mixture from the ilmenite (FeTiO3 and activated carbon was milled for 30 h. This mixture was annealed at 1200 °C for one hour and the product was leached by hydrochloric acid and calcined at 600 °C for two hours. The role of the ball milling was to grind the raw ilmenite to obtain the nano size, and the carbothermic reduction was to reduce all the Fe-Ti phases to a mixture from Fe metal and TiO2. Leaching procedure was carried out to remove all the Fe metal and obtain a high-grade TiO2. After leaching and calcination of the milled and annealed mixture of FeTiO3/C under the optimal conditions, TiO2 nanoparticles with a size of 10–100 nm and purity more than 95% were obtained. The qualifications of the synthesized high purity rutile nanoparticles from the Egyptian natural ilmenite match the conditions of many industrial applications.

  7. Terahertz reflectometry imaging for low and high grade gliomas

    Science.gov (United States)

    Ji, Young Bin; Oh, Seung Jae; Kang, Seok-Gu; Heo, Jung; Kim, Sang-Hoon; Choi, Yuna; Song, Seungri; Son, Hye Young; Kim, Se Hoon; Lee, Ji Hyun; Haam, Seung Joo; Huh, Yong Min; Chang, Jong Hee; Joo, Chulmin; Suh, Jin-Suck

    2016-01-01

    Gross total resection (GTR) of glioma is critical for improving the survival rate of glioma patients. One of the greatest challenges for achieving GTR is the difficulty in discriminating low grade tumor or peritumor regions that have an intact blood brain barrier (BBB) from normal brain tissues and delineating glioma margins during surgery. Here we present a highly sensitive, label-free terahertz reflectometry imaging (TRI) that overcomes current key limitations for intraoperative detection of World Health Organization (WHO) grade II (low grade), and grade III and IV (high grade) gliomas. We demonstrate that TRI provides tumor discrimination and delineation of tumor margins in brain tissues with high sensitivity on the basis of Hematoxylin and eosin (H&E) stained image. TRI may help neurosurgeons to remove gliomas completely by providing visualization of tumor margins in WHO grade II, III, and IV gliomas without contrast agents, and hence, improve patient outcomes. PMID:27782153

  8. Study on leakage rates of high temperature water from wet-type transport casks for spent fuel. Pt. 2. Leakage rates from a scratch on O-ring surface and narrow wires adhering to O-ring surface

    International Nuclear Information System (INIS)

    Asano, R.; Aritomi, M.; Sudi, A.; Kohketsu, Y.

    1997-01-01

    A programme for enhancement of fuel burnup has been promoted in Japan as part of the sophisticated programme for light water reactors to reduce the fuel cost and the amount of spent fuel. As part of this fuel programme, a new wet-type transport cask has been developed to transport the high burnup fuels efficiently. The purpose of this work is to clarify the margin of safety in the evaluation of the release rate of radioactive materials from the wet-type transport cask into the environment and to establish a practical evaluation method for leakage rates on leak behaviour of high temperature water from the casks. In this paper, leakage rates of water under high pressures and at high temperatures are investigated from two kinds of leak path model. One is a disc with a scratch on the surface which simulates a defect on the seal surface of the O-ring flange and the other is narrow stainless steel wires installed on the O-ring surface which simulates hair adhering to the O-ring surface. From the results, an evaluation method for the leakage rate of water under high pressure and at high temperature from a non-circular leak path and multiple leak paths is proposed. (author)

  9. Clinical and molecular features of high-grade osteosarcoma

    NARCIS (Netherlands)

    Anninga, Jakob Klaas

    2013-01-01

    It can be concluded from this thesis that high-grade osteosarcoma is at clinical, pathological and molecular level a heterogeneous disease. To treat high-grade osteosarcoma, neo-adjuvant chemotherapy should be combined with radical surgery, irrespective the localization. There are only 4 effective

  10. Management of high-grade dysplasia in Barrett's esophagus.

    Science.gov (United States)

    Palley, S L; Sampliner, R E; Garewal, H S

    1989-08-01

    When Barrett's esophagus is complicated by adenocarcinoma, surgery is indicated in appropriate patients. Until now, high-grade dysplasia in Barrett's esophagus has been managed in a similar fashion. We explore this approach and review reported cases of high-grade dysplasia to suggest guidelines for collection of data to make future clinical decisions more rational.

  11. Report on the progress of work in Portugal [Processing of Low-Grade Uranium Ores]; Rapport sur l'etat d'avancement des travaux au Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Carreira Pich, H [Junta de Energia Nuclear, Laboratorio de Fisica e Engenharia Nucleares, Sacavem (Portugal)

    1967-06-15

    The purpose of the principal studies until now in Portugal were the development of two types of treatment of the uranium minerals: - Traditional leaching by agitation of the ore milled in a finely sulphuric acid solution; - Leaching of the type 'heap leaching' in which the ore is hard crushed, and then sprinkles is crammed with sulphuric acid solution. Leaching tests were performed traditionally with samples of available Portuguese minerals. In most cases, the dissolution of uranium is easy and low consumption of acid. Efforts were oriented in the direction of a leaching type 'heap leaching'.

  12. Treatment of an isolated high-grade, low-tonnage uranium orebody

    International Nuclear Information System (INIS)

    Ajuria-Garza, S.

    1976-01-01

    A completely integrated process leading to a commercial-grade uranium concentrate has been developed for the El Nopal orebody which contains 115000t of ore with an average grade of 0.283%, equivalent to 325t of U 3 O 8 . The process consists of crushing (from -12 in to -1.5in), heap leaching with recirculation, a special type of countercurrent washing (also in the heap), solvent extraction to give an exceptionally high uranium concentration, re-extraction, precipitation with ammonium hydroxide, filtration and calcining. The main factors that influence heap leaching are analysed in detail: heap geometry, crushed ore size distribution, base design and construction, method of heaping, acid feeding method, flow of liquors through the heap and washing procedures. Leaching efficiencies range from 80 to 85% and washing efficiencies from 96 to almost 100% with an overall extraction efficiency of 77 to 85%. Acid consumption is usually less than 25kg/t of ore. The leaching and washing processes described are designed to use an overall solid-to-liquid ratio of about 3:1 thus producing very concentrated liquors with a U 3 O 8 content of about 7g/l. These liquors are filtered and fed directly to a solvent extraction system using Alamine 336 (tri-capryl amine) and isodecanol in kerosene. The high feed concentration makes it possible to use a high concentration of amine. The organic solvent contains 120g/l of Alamine and 98g/l of isodecanol. Re-extraction can be with a saline solution containing 100g/lNH 4 Cl and 250g/l(NH 4 )SO 4 . The strong liquor obtained from re-extraction contains 70-75g/lU 3 O 8 . The remaining steps of precipitation, filtration and calcining can then follow general practice and lead to a product which meets currently accepted commercial specifications. As an alternative, nitrate re-extraction has been shown to produce a solution of about 70g/l which will feed directly to tributyl phosphate (TBP) refining without the necessity of ever producing a

  13. High dose rate brachytherapy in treatment of high grade astrocytomas

    International Nuclear Information System (INIS)

    Garcia-Alejo, R.; Delgado, J.M.; Cerro, E. del; Torres, J.J.; Martinez, R.

    1996-01-01

    From May 1994 to June 1995, 18 patients with high grade astrocytomas were entered prospectively on a selective protocol combining surgery, external beam radiotherapy, stereotactic interstitial implantation with HDR Iridium 192 and chemotherapy. Only those patients with tumor size 100cc or less average dimension, high grade astrocytoma, Karnofsky 70 or greater, unilateral, circumscribed, unifocal, tumor stable or responding to external radiation and supratentorial were included in the study. Ages ranged from 16 to 69 years. There were 13 males and 5 females. Surgery consisted of biopsy only in 3 patients, subtotal resection in 11, and gross total resection in 4 patients. Focal external beam radiation portals included the contrast enhancing mass on CT scan plus a 3 cm margin. The protocol called for minimum tumor dose of 60 Gy to be given in 2 Gy daily fractions. An interstitial brachytherapy boost was to be performed two weeks after the conclusion of external beam radiation. The dose was 30 Gy in 4 fractions. The authors analyze on basis on their personal experience, the possibilities and the limits offered by this therapeutic procedure in neuro-oncology. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically possible with negligible acute morbidity and mortality, and appeared to be effective and may provide for an increase in tumor control in selected cases

  14. Biomarker discovery in high grade sarcomas by mass spectrometry imaging

    OpenAIRE

    Lou, S.

    2017-01-01

    This thesis demonstrates a detailed biomarker discovery Mass Spectrometry Imaging workflow for histologically heterogeneous high grade sarcomas. Panels of protein and metabolite signatures were discovered either distinguishing different histological subtypes or stratifying high risk patients with poor survival.

  15. Photodynamic therapy of Cervical Intraepithelial Neoplasia (CIN) high grade

    Science.gov (United States)

    Carbinatto, Fernanda M.; Inada, Natalia M.; Lombardi, Welington; da Silva, Eduardo V.; Belotto, Renata; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-02-01

    Cervical intraepithelial neoplasia (CIN) is the precursor of invasive cervical cancer and associated with human papillomavirus (HPV) infection. Photodynamic therapy (PDT) is a technique that has been used for the treatment of tumors. PDT is based on the accumulation of a photosensitizer in target cells that will generate cytotoxic reactive oxygen species upon illumination, inducing the death of abnormal tissue and PDT with less damaging to normal tissues than surgery, radiation, or chemotherapy and seems to be a promising alternative procedure for CIN treatment. The CIN high grades (II and III) presents potential indications for PDT due the success of PDT for CIN low grade treatment. The patients with CIN high grade that were treated with new clinic protocol shows lesion regression to CIN low grade 60 days after the treatment. The new clinical protocol using for treatment of CIN high grade shows great potential to become a public health technique.

  16. Computer finds ore

    Science.gov (United States)

    Bell, Peter M.

    Artificial intelligence techniques are being used for the first time to evaluate geophysical, geochemical, and geologic data and theory in order to locate ore deposits. After several years of development, an intelligent computer code has been formulated and applied to the Mount Tolman area in Washington state. In a project funded by the United States Geological Survey and the National Science Foundation a set of computer programs, under the general title Prospector, was used successfully to locate a previously unknown ore-grade porphyry molybdenum deposit in the vicinity of Mount Tolman (Science, Sept. 3, 1982).The general area of the deposit had been known to contain exposures of porphyry mineralization. Between 1964 and 1978, exploration surveys had been run by the Bear Creek Mining Company, and later exploration was done in the area by the Amax Corporation. Some of the geophysical data and geochemical and other prospecting surveys were incorporated into the programs, and mine exploration specialists contributed to a set of rules for Prospector. The rules were encoded as ‘inference networks’ to form the ‘expert system’ on which the artificial intelligence codes were based. The molybdenum ore deposit discovered by the test is large, located subsurface, and has an areal extent of more than 18 km2.

  17. Modelling a uranium ore bioleaching process

    International Nuclear Information System (INIS)

    Chien, D.C.H.; Douglas, P.L.; Herman, D.H.; Marchbank, A.

    1990-01-01

    A dynamic simulation model for the bioleaching of uranium ore in a stope leaching process has been developed. The model incorporates design and operating conditions, reaction kinetics enhanced by Thiobacillus ferroxidans present in the leaching solution and transport properties. Model predictions agree well with experimental data with an average deviation of about ± 3%. The model is sensitive to small errors in the estimates of fragment size and ore grade. Because accurate estimates are difficult to obtain a parameter estimation approach was developed to update the value of fragment size and ore grade using on-line plant information

  18. High-grade and low-grade gliomas: differentiation by using perfusion MR imaging

    International Nuclear Information System (INIS)

    Hakyemez, B.; Erdogan, C.; Ercan, I.; Ergin, N.; Uysal, S.; Atahan, S.

    2005-01-01

    AIM: Relative cerebral blood volume (rCBV) is a commonly used perfusion magnetic resonance imaging (MRI) technique for the evaluation of tumour grade. Relative cerebral blood flow (rCBF) has been less studied. The goal of our study was to determine the usefulness of these parameters in evaluating the histopathological grade of the cerebral gliomas. METHODS: This study involved 33 patients (22 high-grade and 11 low-grade glioma cases). MRI was performed for all tumours by using a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence followed by conventional MRI. The rCBV and rCBF were calculated by deconvolution of an arterial input function. The rCBV and rCBF ratios of the lesions were obtained by dividing the values obtained from the normal white matter of the contralateral hemisphere. For statistical analysis Mann-Whitney testing was carried out. A p value of less than 0.05 indicated a statistically significant difference. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBV and rCBF ratios and grade of gliomas. Their cut-off value permitting discrimination was calculated. The correlation between rCBV and CBF ratios and glioma grade was assessed using Pearson correlation analysis. RESULTS: In high-grade gliomas, rCBV and rCBF ratios were measured as 6.50±4.29 and 3.32±1.87 (mean±SD), respectively. In low-grade gliomas, rCBV and rCBF ratios were 1.69±0.51 and 1.16±0.38, respectively. The rCBV and rCBF ratios for high-grade gliomas were statistically different from those of low-grade gliomas (p 0.05). The cut-off value was taken as 1.98 in the rCBV ratio and 1.25 in the rCBF ratio. There was a strong correlation between the rCBV and CBF ratios (Pearson correlation = 0.830, p<0.05). CONCLUSION: Perfusion MRI is useful in the preoperative assessment of the histopathologicalal grade of gliomas; the rCBF ratio in addition to the rCBV ratio can be incorporated

  19. Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

    Science.gov (United States)

    Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

    2015-04-01

    India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

  20. Simulation of a high-pressure water jet structure as an innovative tool for pulverizing copper ore in KGHM Polska Miedź S.A.

    Directory of Open Access Journals (Sweden)

    Przemysław Józef Borkowski

    2016-01-01

    Full Text Available Effective comminution of copper ore for further processing during flotation is still a challenge, both as a technological problem as well as for the high energy costs of such processing.A high-pressure water jet is one alternative method of preparing copper ore for final flotation, causing distinct enlargement of the surface of micronized particles, which could be profitable for copper production.As a consequence of such innovative processing, particles of copper ore become micronized, ensuring grain fractions directly useful for flotation at the exit of the pulverizing apparatus (the hydro-jetting mill.The paper presents some results of simulation as well as describing an analysis of the phenomena occurring inside the high-pressure water and abrasive-water jets of specific structures, elaborated in the aspect of developing hybrid jets of maximum erosive efficiency, potentially useful for effective pulverization.

  1. Alunite in the Pascua-Lama high-sulfidation deposit: Constraints on alteration and ore deposition using stable isotope geochemistry

    Science.gov (United States)

    Deyell, C.L.; Leonardson, R.; Rye, R.O.; Thompson, J.F.H.; Bissig, T.; Cooke, D.R.

    2005-01-01

    The Pascua-Lama high-sulfidation system, located in the El Indio-Pascua belt of Chile and Argentina, contains over 16 million ounces (Moz) Au and 585 Moz Ag. The deposit is hosted primarily in granite rocks of Triassic age with mineralization occurring in several discrete Miocene-age phreatomagmatic breccias and related fracture networks. The largest of these areas is Brecha Central, which is dominated by a mineralizing assemblage of alunite-pyrite-enargite and precious metals. Several stages of hydrothermal alteration related to mineralization are recognized, including all types of alunite-bearing advanced argillic assemblages (magmatic-hydrothermal, steam-heated, magmatic steam, and supergene). The occurrence of alunite throughout the paragenesis of this epithermal system is unusual and detailed radiometric, mineralogical, and stable isotope studies provide constraints on the timing and nature of alteration and mineralization of the alunite-pyiite-enargite assemblage in the deposit. Early (preore) alteration occurred prior to ca. 9 Ma and consists of intense silicic and advanced argillic assemblages with peripheral argillic and widespread propylitic zones. Alunite of this stage occurs as fine intergrowths of alunite-quartz ?? kaolinite, dickite, and pyrophyllite that selectively replaced feldspars in the host rock. Stable isotope systematics suggest a magmatic-hydrothermal origin with a dominantly magmatic fluid source. Alunite is coeval with the main stage of Au-Ag-Cu mineralization (alunite-pyrite-enargite assemblage ore), which has been dated at approximately 8.8 Ma. Ore-stage alunite has an isotopic signature similar to preore alunite, and ?? 34Salun-py data indicate depositional temperatures of 245?? to 305??C. The ??D and ?? 18O data exclude significant involvement of meteoric water during mineralization and indicate that the assemblage formed from H2S-dominated magmatic fluids. Thick steam-heated alteration zones are preserved at the highest elevations in

  2. Cognitive impairments in patients with low grade gliomas and high grade gliomas

    Directory of Open Access Journals (Sweden)

    Eliane C. Miotto

    2011-08-01

    Full Text Available OBJECTIVE: The relationship between brain tumors and cognitive deficits is well established in the literature. However, studies investigating the cognitive status in low and high-grade gliomas patients are scarce, particularly in patients with average or lower educational level. This study aimed at investigating the cognitive functioning in a sample of patients with low and high-grade gliomas before surgical intervention. METHOD: The low-grade (G1, n=19 and high-grade glioma (G2, n=8 patients underwent a detailed neuropsychological assessment of memory, executive functions, visuo-perceptive and visuo-spatial abilities, intellectual level and language. RESULTS: There was a significant impairment on verbal and visual episodic memory, executive functions including mental flexibility, nominal and categorical verbal fluency and speed of information processing in G2. G1 showed only specific deficits on verbal and visual memory recall, mental flexibility and processing speed. CONCLUSION: These findings demonstrated different levels of impairments in the executive and memory domains in patients with low and high grade gliomas.

  3. 40 CFR 246.200 - High-grade paper recovery.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-grade paper recovery. 246.200 Section 246.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOURCE... paper recovery. ...

  4. Reducing the Entrainment of Gangue Fines in Low Grade Microcrystalline Graphite Ore Flotation Using Multi-Stage Grinding-Flotation Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Weng

    2017-03-01

    Full Text Available A suitable grinding fineness and flow-sheet could potentially reduce the mechanical entrainment of gangue minerals in the flotation process of microcrystalline graphite. In this study, the suitable grinding fineness of a commercial graphite ore was estimated by mineralogy analysis and laboratory grind-flotation tests. The target grind size of this ore should be 92% passing 74 μm based on the mineralogical evaluation and the flotation performance. A comparison of a single-stage and a three-stage grinding circuit was conducted. Experimental results demonstrated that the three-stage grinding circuit could effectively improve the separation effect, which was attributed to the reduction of slimes. In the end, a more desirable beneficiation result was obtained with the application of three-stage grinding-flotation process by minimizing gangue entrainment.

  5. Utilisation of iron ore tailings as aggregates in concrete

    Directory of Open Access Journals (Sweden)

    Francis Atta Kuranchie

    2015-12-01

    Full Text Available Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

  6. The Influences of Iron Ore Tailings as Fine Aggregate on the Strength of Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Zhigang Zhu

    2015-01-01

    Full Text Available The present study looks for the feasibility of preparing UHPC with iron ore tailings (IOT for short as fine aggregate. To enhance outstanding high performances, some influences on UHPC mortars were investigated such as different kinds of sands, different mix ratio of sands, and different largest particle size of fine aggregate. The results show that IOT have negligible poorer aggregate performance than silica sands but better than river sands. The strength of UHPC reaches the highest point when silica sands were instead 60% by IOT. As the largest particle size of fine aggregate is decreasing, the strength and frost resistance of UHPC were improved, but the liquidity was decreased. Micropowder of IOT affects the strength and the optimal content was 4%.

  7. Use of the high-resolution satellite images for detection of fractures related to the ore deposits

    Science.gov (United States)

    Cruz-Mondaca, M.; Soto-Pinto, C. A.; Arellano-Baeza, A. A.

    2012-12-01

    The Aster and GeoEye satellite high-resolution images were used to detect the structures related to the fracturing of the upper crust in the North of Chile. In particular, lineament analysis has been applied to detect the presence of epithermal fluids of low sulfurization associated with the Paleozoic ore deposits. These results have been compared with the location of the minerals altered by the presence of geothermal fluids detected using the spectral libraries. Later, the presence of fractures has been corroborated during recognition of fractures in situ and the geochemical analysis of samples of minerals altered by the presence of fluids. It was shown that the results obtained are relevant for the gold vein detection.

  8. Magnetic concentration of iron-titanium ore with vanadium concentrate from campo Alegre de Lourdes - Bahia, Brazil

    International Nuclear Information System (INIS)

    Delgado, O.; Silva, F.T. da; Ogasawara, T.; Soares, G.F.

    1988-01-01

    The feasibility studies of magnetic concentration of the Campo Alegre de Lourdes ore were carried out, trying to obtain a maximum recovery of vanadium. As a consequence of the complex nature of the ore, mainly due to the presence of ilmenite as a exolutions in the interior of hematite/martite particles, it was not possible to separate the hematite-ilmenite eficiently, wich would be necessary for obtaining a high grade vanadium concentrate with low titanium content. (author) [pt

  9. High grade leiomyosarcoma of the testes

    Directory of Open Access Journals (Sweden)

    Girish D. Bakhshi

    2011-11-01

    Full Text Available Testicular leiomyosarcoma is a rare tumor. It may arise secondarily following exposure to radiotherapy, chronic inflammation, or usage of high dose anabolic steroids. However, in absence of risk factors, it is rarely seen. Only 15 cases of Primary Intra testicular leiomyosarcoma have been reported in world literature. We present a case of testicular tumor in an elderly male. Preoperative work up showed raised Lactate Dehydrogenase (LDH levels. He underwent high orchidectomy. Histopathology and immunohistochemistry confirmed it to be a primary intra testicular leiomyosarcoma. A brief case report with review of literature is presented.

  10. Grade Crossing Protection in High-Speed, High-Density, Passenger-Service Rail Corridors

    Science.gov (United States)

    1973-01-01

    The report is a preliminary examination of special aspects of grade crossing protection for operation of high-speed passenger trains in rail corridors for which complete grade separation is not possible. Overall system needs and constraints are indic...

  11. Methods of evaluating ore processing and effluent treatment for Cigar Lake ore at the Rabbit Lake Mill

    International Nuclear Information System (INIS)

    Edwards, C.R.

    2002-01-01

    Cigar Lake is the second-largest, high grade uranium orebody in the world. Mineable reserves for Cigar Lake Phase 1 are estimated at 191 million pounds U 3 O 8 with a grade of 25.6% U 3 O 8 . Subject to regulatory approval, Cameco intends to process the majority of ore from Cigar Lake in the Rabbit Lake mill. Cameco initiated a programme to study the processing of Cigar Lake ore and the treatment of the resulting waste streams. Laboratory and follow-up pilot scale ore leaching tests with Cigar Lake ore samples were performed. Tailings and effluents were generated from the products of the pilot scale leach tests. Mill process tailings were blended with ground waste rock. Using these materials, geotechnical and geochemical properties, including long term tailings pore water characteristics, will be evaluated. In addition, proposed changes to the mill waste treatment operations were developed to deal with increased levels of arsenic and radium in the waste streams. This paper describes the methods and techniques Cameco used in this programme. (author)

  12. Determination of rare earth elements in water ore and grass sample around monazite dressing plant by high performance liquid chromatography

    International Nuclear Information System (INIS)

    Laoharojanaphand, S.

    1993-01-01

    High performance liquid chromatography technique for the analysis of rare earth elements; yttrium, cerium and lanthanum, was developed. A comparison of two mobile phases between α-hydroxy isobutyric acid and mandelic acid was carried out using C 1 8 column for separation and the amount of the rare earth elements were detected by post column complex formation with Arsenazo III. It was found that α-hydroxy isobutyric acid had higher efficiency in separation of the rare earth elements than mandelic acid when 1-octanesulfonic acid was used as an organic modifier. The optimum conditions of the mobile phase were comprised of the p H of 3.65, a flow rate of 1 ml/min which resulted in the values of resolution to be 13.62 between yttrium and cerium and 3.49 between cerium and lanthanum. Standard curves of yttrium and lanthanum yielded linear range of 0.1-45 and 1-60 ppm whereas the cerium curve was in the range of 1-100 ppm. The analyses of water, ore and grass samples collected around the monazite dressing plants from Prachuap Khiri Khan and Phuket showed that none of the rare earth elements was detected in all samples from Prachuap Khiri Khan. But 0.5 ppm of yttrium and 1.5 ppm of lanthanum were found in the water samples from Phuket while in the grass samples contained yttrium and cerium in the amounts of 2 ppm and 14 ppm whereas none was detected in the ore samples by this technique under the previous conditions

  13. High grade angiosarcoma arising in fibroadenoma

    Science.gov (United States)

    2011-01-01

    Primary angiosarcoma of the breast is a rare tumour that account for fewer than 0.05% of all malignant mammary tumours. Angiosarcoma may have an perfidious clinical onset. Radiologic findings are often nonspecific and may appear completely normal in one-third of cases with primary angiosarcoma. The prognosis is usually poor because of the high rates of local recurrence and early development of metastases. Aggressive surgical resection is the mainstay of treatment. The role of adjuvant therapy has not yet been well established. Here we present a case of a 53 year old, postmenopausal women with primary angiosarcoma arising in fibroadenoma. To our knowledge, this is the first case described in the literature to date. PMID:22185665

  14. Intensification of the Reverse Cationic Flotation of Hematite Ores with Optimization of Process and Hydrodynamic Parameters of Flotation Cell

    Science.gov (United States)

    Poperechnikova, O. Yu; Filippov, L. O.; Shumskaya, E. N.; Filippova, I. V.

    2017-07-01

    The demand of high grade iron ore concentrates is a major issue due to the depletion of rich iron-bearing ores and high competitiveness in the iron ore market. Iron ore production is forced out to upgrade flowsheets to decrease the silica content in the pelettes. Different types of ore have different mineral composition and texture-structural features which require different mineral processing methods and technologies. The paper presents a comparative study of the cationic and anionic flotation routes to process a fine-grain oxidized iron ore. The modified carboxymethyl cellulose was found as the most efficient depressant in reverse cationic flotation. The results of flotation optimization of hematite ores using matrix of second-order center rotatable uniform design allowed to define the collector concentration, impeller rotation speed and air flowrate as the main flotation parameters impacting on the iron ore concentrate quality and iron recovery in a laboratory flotation machine. These parameters have been selected as independent during the experiments.

  15. The genesis of ores

    International Nuclear Information System (INIS)

    Brimhall, G.

    1991-01-01

    Human history and technology have been shaped by metals. How did they become concentrated in minable deposits located so conveniently near the earth's surface? The author explains the mechanisms of fluid transport-by magma, water and even air and wind-responsible for the chemical and physical interactions that created bodies of metallic ores throughout geologic history. From their formation to their modification at the surface of the earth, ore deposits are geologically transitory and reflect dynamic processes within the earth as well as atmospheric and climatic influences on hydrologic systems. As highly reactive supracrustal systems, they then serve as geochemical sensors providing a powerful record and set of tracer elements for deducing the history, transport paths and forces operative in the crust

  16. Elective neck management for high-grade salivary gland carcinoma.

    Science.gov (United States)

    Herman, Michael P; Werning, John W; Morris, Christopher G; Kirwan, Jessica M; Amdur, Robert J; Mendenhall, William M

    2013-01-01

    To determine whether patients with clinically node negative (cNo) high grade salivary gland carcinomas benefit from an elective neck dissection prior to postoperative radiotherapy (RT). Between October 1964 and October 2009, 59 previously untreated patients with cNo high-grade salivary gland carcinomas (squamous cell carcinomas were excluded) were treated with curative intent using elective neck dissection (END; n=41), or elective neck irradiation (ENI; n=18) at the University of Florida College of Medicine (Gainesville, FL). All patients underwent resection of the primary cancer followed by postoperative RT. The median follow-up period was 5.2years (range, 0.3-34years). Occult metastases were found in 18 (44%) of the 41 patients in the END group. There were 4 recurrences (10%) in the END group and 0 recurrence in the ENI group. Neck control rates at 5years were: END, 90%; ENI, 100%; and overall, 93% (p=0.1879). Cause-specific survival was 94% in the ENI group, 84% in the END group, and 86% for all patients (p=0.6998). There were 3 reported grade 3 or 4 toxicities. Two patients had a postoperative fistula and one patient had a grade 4 osteoradionecrosis that required a partial mandibulectomy. Patients with cNo high grade salivary gland carcinomas who are planned to undergo surgery and postoperative RT likely do not benefit from a planned neck dissection. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Natural resources sustainability: iron ore mining

    International Nuclear Information System (INIS)

    De La Torre de Palacios, Luis

    2011-01-01

    In the present article, a new tool to determine environmental sustainability, the energy impact index (EII) was developed to classify different iron mine projects according to two main parameters including energy consumption and CO 2 emissions. The EII considers the characteristics of the mineral (such as the quality, size, hardness, iron ore grade, reducibility, mineral/waste rate, and type of deposit), mining processes (type of exploitation, ore processing, available technology), and transportation (distance to cover).

  18. Assessment of radioactivity associated with a low ore grade open cast mine at Banduhurang, Jharkhand, India and estimation of occupational exposure to the miners

    International Nuclear Information System (INIS)

    Rana, B.K.; Shukla, A.K.; Topno, R.; Tripathi, R.M.; Puranik, V.D.

    2010-01-01

    The study summarizes radiological characteristics of Banduhurang open cast mine which includes qualitative and quantitative behavior of 222 Rn concentration, external gamma radiation level over the mine pit as well as in its adjoining environment, long-lived alpha (LLα) activity concentration associated with the respirable size of ore dust and assessment of dose to the mine workers in 2006-2008. The investigations reveal that geometric means (χg) of measured radon concentration were 36.39, 38.69, 26.64 and 24 Bq m -3 with respective geometric standard deviations (σg) were 1.52, 1.55, 1.36 and 1.68 Bq m -3 and χg of gamma absorbed dose rates were 0.54, 0.64, 0. 45 and 0.15 μGy h -1 with respective σg were 1.63, 1.53, 1.52 and 1.72 μGy h -1 over the mine pit, ore yard, waste yard and in the surrounding environment within a 10 km radius to the mine, respectively. The χg of LLα activity was observed to be 16 mBq m-3 with σg of 1.9 mBq m -3 . The annual mean effective dose equivalent received by the member radiation workers of Banduhurang mine was estimated to 1.41 mSv y -1 , which is about 7% of the prescribed dose limits of 20 mSv y -1 . (author)

  19. Utilizing a Value of Information Framework to Improve Ore Collection and Classification Procedures

    National Research Council Canada - National Science Library

    Phillips, Julia A

    2006-01-01

    .... We use a value of information framework (VOI) to consider the economic feasibility of a mine purchasing additional information on extracted ore type to reduce the uncertainty of extracted ore grade quality...

  20. Levetiracetam improves verbal memory in high-grade glioma patients

    NARCIS (Netherlands)

    de Groot, Marjolein; Douw, Linda; Sizoo, Eefje M; Bosma, Ingeborg; Froklage, Femke E; Heimans, Jan J; Postma, Tjeerd J; Klein, Martin; Reijneveld, Jaap C

    BACKGROUND: Treatment of high-grade glioma (HGG) patients with anti-epileptic drugs (AEDs) has met with various side effects, such as cognitive deterioration. The cognitive effects of both older and newer AEDs in HGG patients are largely unknown. The aim of this study was to determine the effect of

  1. Bereaved Caregivers to Patients With High-Grade Glioma

    DEFF Research Database (Denmark)

    Piil, Karin; Jarden, Mary

    2018-01-01

    PURPOSE: The disease and treatment trajectory of patients with high-grade glioma is a burdensome period for the patients' closest relatives who become informal caregivers. Caregivers experiencing this demanding shift in role are at risk of developing symptoms such as depression. Few studies have...... care planning within neuro-oncology caregiving to establish evidence-based practice guidelines and recommendations....

  2. Functionally graded materials produced with high power lasers

    NARCIS (Netherlands)

    De Hosson, J. T. M.; Ocelik, V.; Chandra, T; Torralba, JM; Sakai, T

    2003-01-01

    In this keynote paper two examples will be present of functionally graded materials produced with high power Nd:YAG lasers. In particular the conditions for a successful Laser Melt Injection (LMI) of SiC and WC particles into the melt pool of A18Si and Ti6Al4V alloys are presented. The formation of

  3. The Relationship of Grade Span in 9th Grade to Math Achievement in High School

    Science.gov (United States)

    West, John; Miller, Mary Lou; Myers, Jim; Norton, Timothy

    2015-01-01

    Purpose, Scope, and Method of Study: The purpose of this study was to determine if a correlation exists between grade span for ninth grade and gains in math achievement test scores in 10th grade and 12th grade. A quantitative, longitudinal, correlational research design was employed to investigate the research questions. The population was high…

  4. Sintering of manganese ore in natura with different additions on activated carbon

    International Nuclear Information System (INIS)

    Lima, M.M.F.; Mapa, T.F.M.; Lima, R.M.F.

    2016-01-01

    Full text: The shortage of high grade manganese ore and the importance of economically viable processes suggest a necessity of the recovery of ore residues. So, this work presents a route to obtain by-products of economic interest from manganese ore residues in bench scale. The objective was the sintering of manganese ore in natura using a particle size below 0,037μm with different additions of activated carbon. For this, the fine residues were calcined at 800°C during 60 minutes, homogenized in an agate mortar with 12% humidity and additions of 9 and 12% of activated carbon. After homogenization, the sintering process was carried out at 1145°C and 1155°C during 5, 15 and 30 minutes at natural air. The products sintered were characterized by bulk density, BET surface area, OM, SEM / EDS and diffraction X-rays. During the calcination of the ore, the mass loss was (15.16 ± 0.02)% due to the elimination of volatiles and water. The surface area of the ore was reduced due to the diffusion process that occurred during sintering. While, the bulk density values had little variation, around (3.51 ± 0.06)g/cm³. The analyses of micro-regions EDS showed that the matrix is a silicate with a high Mn content. It was identified yet, other silicates with different proportions of Si, Al, Ti, Na, Mn, Mg and Ca. (author)

  5. Sintering of manganese ore in natura with different additions on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.M.F.; Mapa, T.F.M.; Lima, R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2016-07-01

    Full text: The shortage of high grade manganese ore and the importance of economically viable processes suggest a necessity of the recovery of ore residues. So, this work presents a route to obtain by-products of economic interest from manganese ore residues in bench scale. The objective was the sintering of manganese ore in natura using a particle size below 0,037μm with different additions of activated carbon. For this, the fine residues were calcined at 800°C during 60 minutes, homogenized in an agate mortar with 12% humidity and additions of 9 and 12% of activated carbon. After homogenization, the sintering process was carried out at 1145°C and 1155°C during 5, 15 and 30 minutes at natural air. The products sintered were characterized by bulk density, BET surface area, OM, SEM / EDS and diffraction X-rays. During the calcination of the ore, the mass loss was (15.16 ± 0.02)% due to the elimination of volatiles and water. The surface area of the ore was reduced due to the diffusion process that occurred during sintering. While, the bulk density values had little variation, around (3.51 ± 0.06)g/cm³. The analyses of micro-regions EDS showed that the matrix is a silicate with a high Mn content. It was identified yet, other silicates with different proportions of Si, Al, Ti, Na, Mn, Mg and Ca. (author)

  6. High Grade Leiomyosarcoma Mimicking a Recurrent Angiomyxoma in the Perineum.

    Science.gov (United States)

    Sood, Neha; Swaika, Abhisek; Hanooshi, Bashar; Waldorf, James; Peterson, Jennifer; Wu, Kevin; Attia, Steven; Dinh, Tri A

    2015-05-05

    Perineal leiomyosarcoma is an extremely rare and aggressive cancer with a high metastatic potential and no defined standard treatment. There are only a few (six) reported cases in the literature. We report the case of a 67-year-old woman with a perineal leiomyosarcoma arising at the same site of a previously resected superficial angiomyxoma. Initially, she was treated for a presumptive recurrence of angiomyxoma. As she did not respond to medical therapy, she underwent repeat surgical excision. Pathology revealed a high grade leiomyosarcoma, histologically strikingly distinct from the initial diagnosis. She received adjuvant local radiation therapy, and remains without evidence of recurrent disease 36 months after completion of all therapy. This is the first reported case of a high grade perineal leiomyosarcoma originating at the same site as a resected benign superficial angiomyxoma. Our case emphasizes the necessity of a prompt histological diagnosis in cases of presumed recurrent perineal angiomyxoma.

  7. High grade leiomyosarcoma mimicking a recurrent angiomyxoma in the perineum

    Directory of Open Access Journals (Sweden)

    Neha Sood

    2015-05-01

    Full Text Available Perineal leiomyosarcoma is an extremely rare and aggressive cancer with a high metastatic potential and no defined standard treatment. There are only a few (six reported cases in the literature. We report the case of a 67-year-old woman with a perineal leiomyosarcoma arising at the same site of a previously resected superficial angiomyxoma. Initially, she was treated for a presumptive recurrence of angiomyxoma. As she did not respond to medical therapy, she underwent repeat surgical excision. Pathology revealed a high grade leiomyosarcoma, histologically strikingly distinct from the initial diagnosis. She received adjuvant local radiation therapy, and remains without evidence of recurrent disease 36 months after completion of all therapy. This is the first reported case of a high grade perineal leiomyosarcoma originating at the same site as a resected benign superficial angiomyxoma. Our case emphasizes the necessity of a prompt histological diagnosis in cases of presumed recurrent perineal angiomyxoma.

  8. Molecular events leading to HPV-induced high grade neoplasia

    Directory of Open Access Journals (Sweden)

    Saskia M. Wilting

    2016-12-01

    Full Text Available Cervical cancer is initiated by high-risk types of the human papillomavirus (hrHPV and develops via precursor stages, called cervical intraepithelial neoplasia (CIN. High-grade CIN lesions are considered true precancerous lesions when the viral oncogenes E6 and E7 are aberrantly expressed in the dividing cells. This results in abolishment of normal cell cycle control via p53 and pRb degradation. However, it has become clear that these viral oncogenes possess additional oncogenic properties, including interference with the DNA methylation machinery and mitotic checkpoints. Identification of the resulting molecular events leading to high-grade neoplasia will 1 increase our understanding of cervical carcinogenesis, 2 yield biomarkers for early diagnosis, and 3 identify therapeutic targets for HPV-induced (pre cancerous lesions.This review will briefly summarise current advances in our understanding of the molecular alterations in the host cell genome that occur during HPV-induced carcinogenesis.

  9. Identifying high-grade uranium deposits in the Proterozoic basins of India- a challenge to exploration

    International Nuclear Information System (INIS)

    Mahadevan, T.M.

    1995-01-01

    The favorability factors that bestow on the Proterozoic formation of India, a potential to host high grade uranium deposits are discussed in the light of the known features of the new class of unconformity- related and strata bound uranium deposits. The need to reorient several past approaches is emphasised and it is suggested that future programmes must avail of the constraining benefits of a spectrum of geophysical, geochemical, and sedimentological studies in the choice of target areas for detailed exploration and development. A synthesis of geological and geochemical data with such geophysical features as magnetic and gravity anomalies, velocity structure, seismic reflectivity, electrical conductivity, and radioactivity can effectively lead to relatively more favourable exploration targets. Such efforts may lead to the generation of more than one model of the deep basinal features, which then provide wider options for drilling and proving of ore bodies. The alternative to the above approach is saturation drilling, which is a costly and time-consuming process and, therefore, very often self-defeating. (author). 28 refs., 2 figs., 2 tabs

  10. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    Science.gov (United States)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-10-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  11. Analysis of DTI-Derived Tensor Metrics in Differential Diagnosis between Low-grade and High-grade Gliomas.

    Science.gov (United States)

    Jiang, Liang; Xiao, Chao-Yong; Xu, Quan; Sun, Jun; Chen, Huiyou; Chen, Yu-Chen; Yin, Xindao

    2017-01-01

    Purpose: It is critical and difficult to accurately discriminate between high- and low-grade gliomas preoperatively. This study aimed to ascertain the role of several scalar measures in distinguishing high-grade from low-grade gliomas, especially the axial diffusivity (AD), radial diffusivity (RD), planar tensor (Cp), spherical tensor (Cs), and linear tensor (Cl) derived from diffusion tensor imaging (DTI). Materials and Methods: Fifty-three patients with pathologically confirmed brain gliomas (21 low-grade and 32 high-grade) were included. Contrast-enhanced T1-weighted images and DTI were performed in all patients. The AD, RD, Cp, Cs, and Cl values in the tumor zone, peritumoral edema zone, white matter (WM) adjacent to edema and contralateral normal-appearing white matter (NAWM) were calculated. The DTI parameters and tumor grades were statistically analyzed, and receiver operating characteristic (ROC) curve analysis was also performed. Results: The DTI metrics in the affected hemisphere showed significant differences from those in the NAWM, except for the AD values in the tumor zone and the RD values in WM adjacent to edema in the low-grade groups, as well as the Cp values in WM adjacent to edema in the high-grade groups. AD in the tumor zone as well as Cs and Cl in WM adjacent to edema revealed significant differences between the low- and high-grade gliomas. The areas under the curve (Az) of all three metrics were greater than 0.5 in distinguishing low-grade from high-grade gliomas by ROC curve analysis, and the best DTI metric was Cs in WM adjacent to edema (Az: 0.692). Conclusion: AD in the tumor zone as well as Cs and Cl in WM adjacent to edema will provide additional information to better classify gliomas and can be used as non-invasive reliable biomarkers in glioma grading.

  12. Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Wenguang Du

    2017-01-01

    Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

  13. High-grade surface osteosarcoma of the hand

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Kuniko; Hayashi, Tomayoshi; Kinoshita, Naoe [Nagasaki University Hospital, Department of Pathology, Nagasaki (Japan); Kumagai, Kenji; Shindo, Hiroyuki [Nagasaki University Graduate School of Biomedical Sciences, Department of Orthopedic Surgery, Nagasaki (Japan); Uetani, Masataka [Nagasaki University Graduate School of Biomedical Sciences, Department of Radiology and Radiation Biology, Nagasaki (Japan); Ishida, Tsuyoshi [National Center of Neurology and Psychiatry, Department of Pathology and Laboratory Medicine, Kohnodai Hospital, Chiba (Japan); Tokyo Medical and Dental University, Department of Molecular Bone and Cartilage Pathology, Hard Tissue Genome Research Center, Tokyo (Japan)

    2007-09-15

    A 32-year-old woman presented with a 1-year history of mild pain in the right ring finger. Radiographs and CT revealed a calcified lesion with cortical erosion on the surface of the proximal aspect of the right ring finger proximal phalanx. On magnetic resonance imaging (MRI), the lesion showed low signal intensity on T1- and T2-weighted images and slight enhancement with gadolinium. Clinically, it was diagnosed as a benign bone-forming lesion such as florid reactive periostitis, and excision was accordingly performed. However, histological examination revealed proliferation of atypical osteoblastic cells among irregularly arranged osteoid seams. Taking the imaging findings into account, a pathological diagnosis of high-grade surface osteosarcoma was established. In general, bone- and cartilage-forming lesions of the hands and feet are benign. Osteosarcoma of short tubular bones in the hands and feet is extremely rare; moreover, high-grade surface osteosarcoma is one of the rarest subtypes of osteosarcoma. Nonetheless, high-grade surface osteosarcoma should be included in the differential diagnosis, particularly if the radiological findings or clinical course are not entirely typical of a more common benign process, to avoid incorrect clinicoradiological and pathological diagnosis. (orig.)

  14. High-grade surface osteosarcoma of the hand

    International Nuclear Information System (INIS)

    Abe, Kuniko; Hayashi, Tomayoshi; Kinoshita, Naoe; Kumagai, Kenji; Shindo, Hiroyuki; Uetani, Masataka; Ishida, Tsuyoshi

    2007-01-01

    A 32-year-old woman presented with a 1-year history of mild pain in the right ring finger. Radiographs and CT revealed a calcified lesion with cortical erosion on the surface of the proximal aspect of the right ring finger proximal phalanx. On magnetic resonance imaging (MRI), the lesion showed low signal intensity on T1- and T2-weighted images and slight enhancement with gadolinium. Clinically, it was diagnosed as a benign bone-forming lesion such as florid reactive periostitis, and excision was accordingly performed. However, histological examination revealed proliferation of atypical osteoblastic cells among irregularly arranged osteoid seams. Taking the imaging findings into account, a pathological diagnosis of high-grade surface osteosarcoma was established. In general, bone- and cartilage-forming lesions of the hands and feet are benign. Osteosarcoma of short tubular bones in the hands and feet is extremely rare; moreover, high-grade surface osteosarcoma is one of the rarest subtypes of osteosarcoma. Nonetheless, high-grade surface osteosarcoma should be included in the differential diagnosis, particularly if the radiological findings or clinical course are not entirely typical of a more common benign process, to avoid incorrect clinicoradiological and pathological diagnosis. (orig.)

  15. Research of geological technologic condition in laboratory about the ore of 501 deposits

    International Nuclear Information System (INIS)

    Ma Guoxiang; Yu Baoli; Gao Yuyou; Li Changhua

    2009-01-01

    501 deposits of uranium ore grade is 0.052%. The radio of U +6 /U 4+ is 1.7-4.6. there is less content of sarbonate, such as sulfide and organic matter which disservice baptist uranium geological process, and the uranium and oxygen with a high level in the water of seam. The content of [HCO 3 ] - is lower. By conducting the static leaching test, the important technical parameters of uranium ore extraction are determined: with 7.91 g/L H 2 SO 4 , to soak uranium ore which the grade is between 0.007% and 0.216% for 48 hours, the uranium extraction rate of 64.69-99.17%, and extract uranium concentration 9.51-427.6 mg/L; the formula of infusion solution is obtained by using percolation leaching test: 6-8 g/L H 2 SO 4 , the rate of uranium extraction is 95.71%-96.33%, an average of leaching solution uranium concentration of 88.33-111.32 mg/L, leaching liquid-solid ratio of 4.46-5.66, ore tons of sulfuric acid consumption to 27.58-29.83 kg/t, extraction of uranium 1 kg of sulfuric acid consumption to 55.17-60.06 kg. That indicate the geological technologic conditions which the leaching of uranium ore deposits is better. (authors)

  16. Uranium ore deposits: geology and processing implications

    International Nuclear Information System (INIS)

    Belyk, C.L.

    2010-01-01

    There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique set of geological characteristics which may also result in unique processing implications. Primary uranium production in the past decade has predominantly come from only a few of these deposit types including: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic ones. Processing implications can vary widely between and within the different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy, ore hardness, porosity, uranium mineral morphology and carbon content. Processing difficulties may occur as a result of one or more of these characteristics. In order to meet future uranium demand, it is imperative that innovative processing approaches and new technological advances be developed in order that many of the marginally economic traditional and uneconomic non-traditional uranium ore deposits can be exploited. (author)

  17. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    International Nuclear Information System (INIS)

    Wang Zhengqi; Wu Lieqin; Zhang Guoyu

    2007-12-01

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO 2 , F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  18. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    Energy Technology Data Exchange (ETDEWEB)

    Zhengqi, Wang [East China Inst. of Technology, Fuzhou (China); [Beijing Research Inst. of Uranium Geology, Beijing (China); Lieqin, Wu [Institute No.290, CNNC, Shaoguan (China); Guoyu, Zhang [East China Inst. of Technology, Fuzhou (China)

    2007-12-15

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO{sub 2}, F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  19. Multiphoton imaging of low grade, high grade intraepithelial neoplasia and intramucosal invasive cancer of esophagus

    Science.gov (United States)

    Xu, Jian; Jiang, Liwei; Kang, Deyong; Wu, Xuejing; Xu, Meifang; Zhuo, Shuangmu; Zhu, Xiaoqin; Lin, Jiangbo; Chen, Jianxin

    2017-04-01

    Esophageal squamous cell carcinoma (ESCC) is devastating because of its aggressive lymphatic spread and clinical course. It is believed to occur through low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and intramucosal invasive cancer (IMC) before transforming to submucosal cancer. In particular, these early lesions (LGIN, HGIN and IMC), which involve no lymph node nor distant metastasis, can be cured by endoscopic treatment. Therefore, early identification of these lesions is important so as to offer a curative endoscopic resection, thus slowing down the development of ESCC. In this work, spectral information and morphological features of the normal esophageal mucosa are first studied. Then, the morphological changes of LGIN, HGIN and IMC are described. Lastly, quantitative parameters are also extracted by calculating the nuclear-to-cytoplasmic ratio of epithelial cells and the pixel density of collagen in the lamina propria. These results show that multiphoton microscopy (MPM) has the ability to identify normal esophageal mucosa, LGIN, HGIN and IMC. With the development of multiphoton endoscope systems for in vivo imaging, combined with a laser ablation system, MPM has the potential to provide immediate pathologic diagnosis and curative treatment of ESCC before the transformation to submucosal cancer in the future.

  20. Characterization of Anisotropic Behavior for High Grade Pipes

    Science.gov (United States)

    Yang, Kun; Huo, Chunyong; Ji, Lingkang; Li, Yang; Zhang, Jiming; Ma, Qiurong

    With the developing requirement of nature gas, the property needs of steel for pipe line are higher and higher, especially in strength and toughness. It is necessary to improve the steel grade in order to ensure economic demand and safety. However, with the rise of steel grade, the differences on properties in different orientations (anisotropic behaviors) become more and more obvious after the process of hot rolling, which may affect the prediction of fracture for the pipes seriously (Thinking of isotropic mechanical properties for material in traditional predict way). In order to get the reason for anisotropic mechanics, a series of tests are carried out for high grade steel pipes, including not only mechanical properties but also microstructures. Result indicates that there are obviously anisotropic behaviors for high grade steel pipes in two orientations (rolling orientation and transverse orientation). Strength is better in T orientation because Rm is higher and Rt 0.5 rises more in T orientation, and toughness is better in L orientation because of the higher Akv and SA in L orientation under a same temperature. Banded structures are formed in T orientation, and the spatial distribution of inclusion and precipitated phases are different in T, L and S orientation. The anisotropic arrangement for the matrix in space (banded structures), which is formed after the process of hot rolling, may affect the mechanical properties in different orientation. Moreover, the elasticity modulus of particles is different from the elasticity modulus of matrix, deformation between particles and matrix may cause stress concentration, and damage forms in this place. Because of the different distribution of particles in space, the level of damage is anisotropic in different orientations, and the anisotropic mechanical properties occur finally. Therefore, the anisotropic mechanical properties are determined by the anisotropic microstructures, both the anisotropic of matrix and the

  1. Differentiating high-grade from low-grade chondrosarcoma with MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hye Jin; Hong, Sung Hwan; Choi, Ja-Young; Choi, Jung-Ah; Kang, Heung Sik [Seoul National University College of Medicine, Department of Radiology and Institute of Radiation Medicine, Seoul (Korea); Moon, Kyung Chul [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea); Kim, Han-Soo [Seoul National University College of Medicine, Department of Orthopedic Surgery, Seoul (Korea)

    2009-12-15

    The purpose of the study was to evaluate the MR imaging features that differentiate between low-grade chondrosarcoma (LGCS) and high-grade chondrosarcoma (HGCS) and to determine the most reliable predictors for differentiation. MR images of 42 pathologically proven chondrosarcomas (28 LGCS and 14 HGCS) were retrospectively reviewed. There were 13 male and 29 female patients with an age range of 23-72 years (average age 51 years). On MR images, signal intensity, specific morphological characteristics including entrapped fat, internal lobular architecture, and outer lobular margin, soft tissue mass formation and contrast enhancement pattern were analysed. MR imaging features used to identify LGCS and HGCS were compared using univariate analysis and multivariate stepwise logistic regression analysis. On T1-weighted images, a central area of high signal intensity, which was not seen in LGCS, was frequently observed in HGCS (n = 5, 36%) (p < 0.01). Entrapped fat within the tumour was commonly seen in LGCS (n = 26, 93%), but not in HGCS (n = 1, 4%) (p < 0.01). LGCS more commonly (n = 24, 86%) preserved the characteristic internal lobular structures within the tumour than HGCSs (n = 4, 29%) (p < 0.01). Soft tissue formation was more frequently observed in HGCS (n = 11, 79%) than in LGCS (n = 1, 4%) (p < 0.01). On gadolinium-enhanced images, large central nonenhancing areas were exhibited in only two (7.1%) of LGCS, while HGCS frequently (n = 9, 64%) had a central nonenhancing portion (p < 0.01). Results of multivariate stepwise logistic regression analysis showed that soft tissue formation and entrapped fat within the tumour were the variables that could be used to independently differentiate LGCS from HGCS. There were several MR imaging features of chondrosarcoma that could be helpful in distinguishing HGCS from LGCS. Among them, soft tissue mass formation favoured the diagnosis of HGCS, and entrapped fat within the tumour was highly indicative of LGCS. (orig.)

  2. Differentiating high-grade from low-grade chondrosarcoma with MR imaging

    International Nuclear Information System (INIS)

    Yoo, Hye Jin; Hong, Sung Hwan; Choi, Ja-Young; Choi, Jung-Ah; Kang, Heung Sik; Moon, Kyung Chul; Kim, Han-Soo

    2009-01-01

    The purpose of the study was to evaluate the MR imaging features that differentiate between low-grade chondrosarcoma (LGCS) and high-grade chondrosarcoma (HGCS) and to determine the most reliable predictors for differentiation. MR images of 42 pathologically proven chondrosarcomas (28 LGCS and 14 HGCS) were retrospectively reviewed. There were 13 male and 29 female patients with an age range of 23-72 years (average age 51 years). On MR images, signal intensity, specific morphological characteristics including entrapped fat, internal lobular architecture, and outer lobular margin, soft tissue mass formation and contrast enhancement pattern were analysed. MR imaging features used to identify LGCS and HGCS were compared using univariate analysis and multivariate stepwise logistic regression analysis. On T1-weighted images, a central area of high signal intensity, which was not seen in LGCS, was frequently observed in HGCS (n = 5, 36%) (p < 0.01). Entrapped fat within the tumour was commonly seen in LGCS (n = 26, 93%), but not in HGCS (n = 1, 4%) (p < 0.01). LGCS more commonly (n = 24, 86%) preserved the characteristic internal lobular structures within the tumour than HGCSs (n = 4, 29%) (p < 0.01). Soft tissue formation was more frequently observed in HGCS (n = 11, 79%) than in LGCS (n = 1, 4%) (p < 0.01). On gadolinium-enhanced images, large central nonenhancing areas were exhibited in only two (7.1%) of LGCS, while HGCS frequently (n = 9, 64%) had a central nonenhancing portion (p < 0.01). Results of multivariate stepwise logistic regression analysis showed that soft tissue formation and entrapped fat within the tumour were the variables that could be used to independently differentiate LGCS from HGCS. There were several MR imaging features of chondrosarcoma that could be helpful in distinguishing HGCS from LGCS. Among them, soft tissue mass formation favoured the diagnosis of HGCS, and entrapped fat within the tumour was highly indicative of LGCS. (orig.)

  3. Predicting the Concentration Characteristics of Itakpe Iron Ore for cut ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: Concentration characteristics of an ore are very critical to the estimation of cut-off grade of a ... enormous financial cost of laboratory analysis and time required for such .... Arua A.I. (1997) Fundamentals of statistics, Publisher,.

  4. Determination of vanadium in high grade carbons by radioanalytical methods

    International Nuclear Information System (INIS)

    Jinno, K.; Sato, M.; Amemiya, S.; Katoh, T.

    1980-01-01

    The present work deals with the determination of vanadium in high grade carbons by three radioanalytical methods, viz. thermal neutron activation analysis with an accelerator, thermal neutron activation analysis with a reactor and proton induced X-ray emission analysis with an accelerator. It is shown that thermal neutron activation with an accelerator is more convenient for the rapid and non-destructive analysis of ppm-level vanadium in bulk carbons than thermal neutron activation analysis with a reactor. Proton-induced X-ray emission is less useful for the analysis of bulk samples. (author)

  5. Heap leaching of clay ish uranium ores

    International Nuclear Information System (INIS)

    Gonzalez, E.; Sedano, A.

    1973-01-01

    This paper describes an experimental facility, built near El Lobo mine. In it we study the beneficiation of low-grade uranium ore. The mineral has a great amount of clay and fines. The flow-sheet used has four steps: head leaching, ph-ajustement, ion-exchange and participation. We show, also, the most interesting results. (Author)

  6. Deciphering fluid inclusions in high-grade rocks

    Directory of Open Access Journals (Sweden)

    Alfons van den Kerkhof

    2014-09-01

    Full Text Available The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary inclusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the “original” peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence (CL techniques combined with trace element analysis of quartz (EPMA, LA-ICPMS have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and Al, low-temperature re-equilibrated quartz typically shows reduced trace element concentrations. The resulting microstructures in CL can be basically distinguished in diffusion patterns (along microfractures and grain boundaries, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 °C, i.e. the range of semi-brittle deformation (greenschist-facies and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

  7. High-performance reagent modes for flotation recovery of platiniferous copper and nickel sulfides from hard-to-beneficiate ores

    Science.gov (United States)

    Matveeva, T. N.; Chanturiya, V. A.

    2017-07-01

    The paper presents the results of the recent research performed in IPKON Russian Academy of Sciences that deals with development and substantiation of new selective reagents for effective flotation recovery of non-ferrous and noble metals from refractory ores. The choice and development of new selective reagents PTTC, OPDTC, modified butylxanthate (BXm) and modified diethyl-dithiocarbamate (DEDTCm) to float platiniferous copper and nickel sulfide minerals from hard-to-beneficiate ores is substantiated. The mechanism of reagents adsorption and regulation of minerals floatability is discussed. The study of reagent modes indicates that by combining PTTC with the modified xanthate results in 6 - 7 % increase in the recovery of copper, nickel and PGM in the flotation of the low-sulfide platiniferous Cu-Ni ore from the Fedorovo-Panskoye deposit. The substitution of OPDTC for BX makes it possible to increase recovery of Pt by 13 %, Pd by 9 % and 2 - 4 times the noble metal content in the flotation concentrate.

  8. Genomic characterization of recurrent high-grade astroblastoma.

    Science.gov (United States)

    Bale, Tejus A; Abedalthagafi, Malak; Bi, Wenya Linda; Kang, Yun Jee; Merrill, Parker; Dunn, Ian F; Dubuc, Adrian; Charbonneau, Sarah K; Brown, Loreal; Ligon, Azra H; Ramkissoon, Shakti H; Ligon, Keith L

    2016-01-01

    Astroblastomas are rare primary brain tumors, diagnosed based on histologic features. Not currently assigned a WHO grade, they typically display indolent behavior, with occasional variants taking a more aggressive course. We characterized the immunohistochemical characteristics, copy number (high-resolution array comparative genomic hybridization, OncoCopy) and mutational profile (targeted next-generation exome sequencing, OncoPanel) of a cohort of seven biopsies from four patients to identify recurrent genomic events that may help distinguish astroblastomas from other more common high-grade gliomas. We found that tumor histology was variable across patients and between primary and recurrent tumor samples. No common molecular features were identified among the four tumors. Mutations commonly observed in astrocytic tumors (IDH1/2, TP53, ATRX, and PTEN) or ependymoma were not identified. However one case with rapid clinical progression displayed mutations more commonly associated with GBM (NF1(N1054H/K63)*, PIK3CA(R38H) and ERG(A403T)). Conversely, another case, originally classified as glioblastoma with nine-year survival before recurrence, lacked a GBM mutational profile. Other mutations frequently seen in lower grade gliomas (BCOR, BCORL1, ERBB3, MYB, ATM) were also present in several tumors. Copy number changes were variable across tumors. Our findings indicate that astroblastomas have variable growth patterns and morphologic features, posing significant challenges to accurate classification in the absence of diagnostically specific copy number alterations and molecular features. Their histopathologic overlap with glioblastoma will likely confound the observation of long-term GBM "survivors". Further genomic profiling is needed to determine whether these tumors represent a distinct entity and to guide management strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Magnetic resonance perfusion for differentiating low-grade from high-grade gliomas at first presentation.

    Science.gov (United States)

    Abrigo, Jill M; Fountain, Daniel M; Provenzale, James M; Law, Eric K; Kwong, Joey Sw; Hart, Michael G; Tam, Wilson Wai San

    2018-01-22

    Gliomas are the most common primary brain tumour. They are graded using the WHO classification system, with Grade II-IV astrocytomas, oligodendrogliomas and oligoastrocytomas. Low-grade gliomas (LGGs) are WHO Grade II infiltrative brain tumours that typically appear solid and non-enhancing on magnetic resonance imaging (MRI) scans. People with LGG often have little or no neurologic deficit, so may opt for a watch-and-wait-approach over surgical resection, radiotherapy or both, as surgery can result in early neurologic disability. Occasionally, high-grade gliomas (HGGs, WHO Grade III and IV) may have the same MRI appearance as LGGs. Taking a watch-and-wait approach could be detrimental for the patient if the tumour progresses quickly. Advanced imaging techniques are increasingly used in clinical practice to predict the grade of the tumour and to aid clinical decision of when to intervene surgically. One such advanced imaging technique is magnetic resonance (MR) perfusion, which detects abnormal haemodynamic changes related to increased angiogenesis and vascular permeability, or "leakiness" that occur with aggressive tumour histology. These are reflected by changes in cerebral blood volume (CBV) expressed as rCBV (ratio of tumoural CBV to normal appearing white matter CBV) and permeability, measured by K trans . To determine the diagnostic test accuracy of MR perfusion for identifying patients with primary solid and non-enhancing LGGs (WHO Grade II) at first presentation in children and adults. In performing the quantitative analysis for this review, patients with LGGs were considered disease positive while patients with HGGs were considered disease negative.To determine what clinical features and methodological features affect the accuracy of MR perfusion. Our search strategy used two concepts: (1) glioma and the various histologies of interest, and (2) MR perfusion. We used structured search strategies appropriate for each database searched, which included: MEDLINE

  10. Sustainability of Water Cooled Reactors - Energy Balance for Low Grade Uranium Resources

    International Nuclear Information System (INIS)

    Strupczewski, A.

    2011-01-01

    The opponents of nuclear power claim that as uranium resources get exhausted the energy needed to mine low grade uranium ore will be larger than the energy that can be obtained from fission in a nuclear power plant. This would result in loss of sustainability of nuclear power, with the negative energy balance expected within the next 40-60 years. Since the opponents state clearly that the ore containing less than 0.013% U 3 O 8 cannot yield positive energy balance, the study of the Institute of Atomic Energy in Poland referenced three mines of decreasing ore grade: Ranger 0.234% U 3 O 8 , Rossing 0.028% U 3 O 8 and Trekkopje 0.00126% U 3 O 8 , that is with ore grade below the postulated cut off value. The study considered total energy needs for uranium mining, including not only electricity needed for mining and milling, for water treatment and delivery, but also fuel for transportation and ore crushing, explosives for rock blasting, chemicals for uranium leaching and the energy needed for mine reclamation after completed exploitation. It has been shown that the energy estimates of nuclear opponents are wrong for Ranger mine and go off much further for the mines with lower uranium ore grades. The reasons for erroneous reasoning of nuclear opponents have been found. Their errors arise from treating the uranium ore deposits as if their layout and properties were the same as those of uranium ore mined in the US in the 70-ies. This results in an oversimplified formula, which yields large errors when the thickness of the overlayer is less than it was in the US. In addition the energy needs claimed for mine reclamation are much too high. The study showed that the energy needed for very low grade uranium ore mining and milling increases but the overall energy balance of the nuclear fuel cycle remains strongly positive. (author)

  11. DIFFERENT LEVEL OF LEARNED-HELPLESSNESS AMONG HIGH SCHOOL STUDENTS WITH LOWER GRADE AND HIGHER GRADE IN SALATIGA INDONESIA

    Directory of Open Access Journals (Sweden)

    Berta Esti Ari Prasetya

    2013-06-01

    consisted of 190 of higher grade students and 127 of lower grade students. Mann-Whitney U was used to analyse the data, considering that the data were not normally distributed. This test result showed that there was a significant difference between high school students with higher grade and lower grade (the Mann-Whitney U coefficient of 10,644, with z value of -1795, p <0.05 (p = 0036, 1-tailed, with students of lower grade tend to be more prone to experience learned-helplessness. Additional results from their subjective perception on their achievement were also discussed and so were the implications of the study.

  12. Beneficiation and agglomeration of manganese ore fines (an area so important and yet so ignored)

    Science.gov (United States)

    Sane, R.

    2018-01-01

    Unpredictable changes in demand and prices varying from very attractive to depressing levels have thrown all Manganese ore mines out of normal operating gear. The supply has to be in time-bound fashion, of dependable quality and continuous. With setting-up of numerous small units and with existing ferro-alloy units, ore supply has become extremely sensitive issue. Due to unpredictable swing in price of Mn ore lumps, furnace operators found it economic and convenient to use fines, even at great risks to furnace equipment and operating persons and therefore risks & damages were conveniently & comfortably ignored. Beneficiation Cost(Operating) approx. - (ferruginous ore) - Roast reduction followed by magnetic separation route-particulars - Water 20/-, Power 490/-, Coal fines-675/-, OH-250/-totaling to Rs.1435/T. (Figures are based on actual data from investigations on Orissa & Karnataka sector ores). Feed Grade Mn- 28 to 32 %, Fe - 14 to 25 %, Concentrate (Beneficiated ore fines)- - Mn- 45 to 48 %, Fe - 6 to 8 %., Recovery - 35 %, Price of 28-30 % Mn ore fines = Rs. 2400/T, Cost of Concentrated fines (45/48% Mn grade) = Rs. 8300/T, Price of 47-48 % Mn Lumpy ore = Rs.11,000/T. Sintering Cost (Operating) - Approx-Rs.1195=00/T Sinter. Therefore cost of Sinter produced from beneficiated concentrate is 9130+1195 = Rs. 10325. The difference in cost of 48%Mn ore Lumps & 48%Mn sintered concentrate = 11000-10325 = Rs.675/T. The main purpose of this paper is to show that establishment of beneficiation unit & Sintering unit is economically feasible. There are many misconcepts, still prevailing, about use of Mn ore sinters. Few of the main misconcepts are- 1)Sinters bring no benefit - technical or economical.2) Sinters are very friable and disintegrate easily into high fines during handling/transportation. 3) Fines below 100 mesh cannot be sintered. 4) Silica increases to high level during sintering, resulting in to high slag volume thereby higher power consumption. All are false

  13. Report on the actual situation in Spain [Processing of Low-Grade Uranium Ores]; Informe sobre la situacion actual en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Josa, J M [Direccion de Plantas Piloto e Industriales, Junta de Energia Nuclear, Madrid (Spain)

    1967-06-15

    According to the Spanish program of nuclear reactors uranium requirements are estimated from 1400 to 1600 t until 1970 and between 11 000 and 14 000 t until 1980. Prospecting current account with reserves of 11 000 t U{sub 3}O{sub 8} with costs between 5 and 10$/lb U{sub 3}0{sub 8}, 40 000 t with costs from 10 to 15$/lb U{sub 3}O{sub 8} and about 250 000 t with some potential costs between 15 and 30$/lb U{sub 3}0{sub 8}. The reserves for next development (with grades 0, 1-0, 2% U{sub 3}O{sub 8}) are formed by deposits in granitic rocks (40%) and the rest in metamorphic rocks (shales), located in western Spain. The longer term reserves are made up of lignite and sedimentary formations (Miocene central strata, sediments from eastern Spain and Quartzites from Sierra Morena).

  14. Symptom clusters in patients with high-grade glioma.

    Science.gov (United States)

    Fox, Sherry W; Lyon, Debra; Farace, Elana

    2007-01-01

    To describe the co-occurring symptoms (depression, fatigue, pain, sleep disturbance, and cognitive impairment), quality of life (QoL), and functional status in patients with high-grade glioma. Correlational, descriptive study of 73 participants with high-grade glioma in the U.S. Nine brief measures were obtained with a mailed survey. Participants were recruited from the online message board of The Healing Exchange BRAIN TRUST, a nonprofit organization dedicated to improving quality of life for people with brain tumors. Two symptom cluster models were examined. Four co-occurring symptoms were significantly correlated with each other and explained 29% of the variance in QoL: depression, fatigue, sleep disturbance, and cognitive impairment. Depression, fatigue, sleep disturbance, cognitive impairment, and pain were significantly correlated with each other and explained 62% of the variance in functional status. The interrelationships of the symptoms examined in this study and their relationships with QoL and functional status meet the criteria for defining a symptom cluster. The differences in the models of QoL and functional status indicates that symptom clusters may have unique characteristics in patients with gliomas.

  15. Yoga May Mitigate Decreases in High School Grades

    Directory of Open Access Journals (Sweden)

    Bethany Butzer

    2015-01-01

    Full Text Available This study involves an exploratory examination of the effects of a 12-week school-based yoga intervention on changes in grade point average (GPA in 9th and 10th grade students. Participants included 95 high school students who had registered for physical education (PE in spring 2010. PE class sections were group randomized to receive either a yoga intervention or a PE-as-usual control condition. The yoga intervention took place during the entire third quarter and half of the fourth quarter of the school year, and quarterly GPA was collected via school records at the end of the school year. Results revealed a significant interaction between group and quarter suggesting that GPA differed between the yoga and control groups over time. Post hoc tests revealed that while both groups exhibited a general decline in GPA over the school year, the control group exhibited a significantly greater decline in GPA from quarter 1 to quarter 3 than the yoga group. Both groups showed equivalent declines in GPA in quarter 4 after the yoga intervention had ended. The results suggest that yoga may have a protective effect on academic performance by preventing declines in GPA; however these preventive effects may not persist once yoga practice is discontinued.

  16. High-Grade Leiomyosarcoma Arising in a Previously Replanted Limb

    Directory of Open Access Journals (Sweden)

    Tiffany J. Pan

    2015-01-01

    Full Text Available Sarcoma development has been associated with genetics, irradiation, viral infections, and immunodeficiency. Reports of sarcomas arising in the setting of prior trauma, as in burn scars or fracture sites, are rare. We report a case of a leiomyosarcoma arising in an arm that had previously been replanted at the level of the elbow joint following traumatic amputation when the patient was eight years old. He presented twenty-four years later with a 10.8 cm mass in the replanted arm located on the volar forearm. The tumor was completely resected and pathology examination showed a high-grade, subfascial spindle cell sarcoma diagnosed as a grade 3 leiomyosarcoma with stage pT2bNxMx. The patient underwent treatment with brachytherapy, reconstruction with a free flap, and subsequently chemotherapy. To the best of our knowledge, this is the first case report of leiomyosarcoma developing in a replanted extremity. Development of leiomyosarcoma in this case could be related to revascularization, scar formation, or chronic injury after replantation. The patient remains healthy without signs of recurrence at three-year follow-up.

  17. Does Small Prostate Predict High Grade Prostate Cancer?

    International Nuclear Information System (INIS)

    Caliskan, S.; Kaba, S.; Koca, O.; Ozturk, M. I.

    2017-01-01

    Objective: The current study is aimed to assess the patients who underwent radical prostatectomy for prostate cancer and investigate the association between prostate size and adverse outcomes at final pathology. Study Design: Comparative, descriptive study. Place and Duration of Study: Haydarpasa Numune Training and Research Hospital, Turkey, from January 2008 to January 2016. Methodology: The patients treated with open radical prostatectomy for prostate cancer were reviewed. Patient characteristics including prostate specific antigen (PSA), free PSA levels, age, biopsy, and radical prostatectomy results were recorded. The patients whose data were complete or prostate weight was equal to or less than 80 gm, were included in the study. Patients with < 40 gm prostate weight was in group 1 and the patients in group 2 had a prostate weight from 40 to 80 gm. High grade prostate cancer was defined to have a Gleason score between 7 or higher at biopsy and final pathology. Pathology and biopsy results were compared within groups. MedCalc Statistical Software demo version was used for statistical analyses. Results: There were 162 patients in this study. Of these, 71 (43.82 percent) patients were in group 1 and 91 (56.17 percent) patients were in group 2. The age ranged from 49 to 76 years. Mean value of 62.70 +-6.82 and 65.82 +- 5.66 years in group 1 and 2, respectively. Fifty (70.42 percent) and 68 patients (74.74 percent) had a Gleason score of 6 in group 1 and 2, respectively. Organconfined disease was reported in 53 patients (74.64 percent) in group 1 and in 78 patients (85.71 percent) in group 2. Gleason score concordance between biopsy and prostatectomy was reported in 61 patients (67.03 percent) and downgrading was detected in 4 patients (4.4 percent) in group 2. The median tumor volume of the patients was 4.47 cm/sup 3/ in group 1 and 6 cm/sup 3/ in group 2 (p=0.502). High grade prostate cancer was reported in 52.11 percent and 45.05 percent of the patients in

  18. Pharmacokinetic MRI of the prostate. Parameters for differentiating low-grade and high-grade prostate cancer

    International Nuclear Information System (INIS)

    Franiel, T.; Taupitz, M.; Asbach, P.; Beyersdorff, D.; Luedemann, L.; Rost, J.

    2009-01-01

    Purpose: to investigate whether pharmacokinetic MRI parameters ''perfusion, blood volume, mean transit time (MTT), interstitial volume, permeability, extraction coefficient, delay, and dispersion'' allow the differentiation of low-grade (Gleason score ≤ 6) and high-grade (Gleason score ≥ 7) prostate cancer. Materials and method: forty-two patients with prostate cancer verified by biopsy (PSA 2.7 to 31.4ng/ml) and scheduled for prostatectomy underwent MRI at 1.5 Tesla using the dynamic contrast-enhanced inversion-prepared dual-contrast gradient echo sequence (temporal resolution, 1.65 s) and a combined endorectal body phased array coil. Parametric maps were computed using a sequential 3-compartment model and the corresponding post-processing algorithms. A total of 41 areas of prostate cancer (15 low-grade, 26 high-grade cancers) in 32 patients were able to be correlated with the prostatectomy specimens and were included in the analysis. Results: low-grade prostate cancers had a higher mean blood volume (1.76% vs. 1.64%, p = 0.039), longer MTT (6.39 s vs. 3.25 s, p -1 vs. 3.86 min -1 , p = 0.011) than high-grade cancers. No statistically significant difference was found for perfusion (p = 0.069), interstitial volume (p = 0.849), extraction coefficient (p = 0.615), delay (p = 0.489), and dispersion (p = 0.306). (orig.)

  19. New insights into the extraction of invisible gold in a low-grade high-sulfur Carlin-type gold concentrate by bio-pretreatment

    Science.gov (United States)

    Qiu, Xiao-bin; Wen, Jian-kang; Huang, Song-tao; Yang, Hong-ying; Liu, Mei-lin; Wu, Biao

    2017-10-01

    To extract gold from a low-grade (13.43 g/t) and high-sulfur (39.94wt% sulfide sulfur) Carlin-type gold concentrate from the Nibao deposit, Guizhou, a bio-pretreatment followed by carbon-in-pulp (CIP) cyanide leaching process was used. Various methods were used to detect the low-grade gold in the concentrate; however, only time-of-flight secondary-ion mass spectrometry (TOF-SIMS) was successful. With bio-pretreatment, the gold recovery rate increased by approximately 70.16% compared with that obtained by direct cyanide leaching of the concentrate. Various attempts were made to increase the final gold recovery rate. However, approximately 20wt% of the gold was non-extractable. To determine the nature of this non-extractable gold, mineralogy liberation analysis (MLA), formation of secondary product during the bio-pretreatment, and the preg-robbing capacity of the carbonaceous matter in the ore were investigated. The results indicated that at least four factors affected the gold recovery rate: gold occurrence, tight junctions of gold-bearing pyrite with gangue minerals, jarosite coating of the ore, and the carbonaceous matter content.

  20. High grade serous ovarian carcinomas originate in the fallopian tube.

    Science.gov (United States)

    Labidi-Galy, S Intidhar; Papp, Eniko; Hallberg, Dorothy; Niknafs, Noushin; Adleff, Vilmos; Noe, Michael; Bhattacharya, Rohit; Novak, Marian; Jones, Siân; Phallen, Jillian; Hruban, Carolyn A; Hirsch, Michelle S; Lin, Douglas I; Schwartz, Lauren; Maire, Cecile L; Tille, Jean-Christophe; Bowden, Michaela; Ayhan, Ayse; Wood, Laura D; Scharpf, Robert B; Kurman, Robert; Wang, Tian-Li; Shih, Ie-Ming; Karchin, Rachel; Drapkin, Ronny; Velculescu, Victor E

    2017-10-23

    High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.

  1. Radio-fluoro guided surgery in high grade gliomas

    International Nuclear Information System (INIS)

    Lopez Piloto, Orestes; Salva Camano, Silvia; Gonzalez Gonzalez, Justo; Cruz Hernandez, Tania Margarita; Martinez Suarez, Eduardo; Lopez Arbolay, Omar; Ardisana Santana, Ernesto

    2015-01-01

    The MIBI (99mTc MIBI, methoxyisobutylisonitrile, MIBI, or sestamibi): is a wide readiness to the rich flow of photons, which improves the detection of pathological uptake with gamma probe, these physical properties make of this radiotracer the election to radioguided surgery. The sodium fluorescein is a water-soluble organic coloring substance used in the exam of the sanguine glasses of the eye. We carried out the report of five cases diagnosed with brain tumor of high grade of malignancy, with the objective to demonstrated that use of Radio-Fluro-guided Surgery (RFGS) we can achieve gross total resections without bigger deficit, completing the inclusion and exclusion criteria. The technique of RFGS demonstrated utility in the gross total resection, diminishing the residual tumor, without increasing surgery complexity and surgical times. In our study doesn't evidence of adverse effects for the administration of the radiopharmaceuticals and fluorescein

  2. Uranium ores of Kazakhstan as the most technologic source of a fissionable material

    International Nuclear Information System (INIS)

    Berikbolov, B.R.

    1999-01-01

    Kazakhstan as is known has unique deposits of uranium. Its resources composed a third part of the world resources. The most important part of resources having a practical value, is related with depression in southern regions of the Republic. By now more than 15 deposits are discovered and partially explored. These deposits from three uranium provinces - Shu-Sarysu, Syr-Darya and Ili. The ores occur in friable water-bearing sandy horizons of Cretaceous and Paleogene age between waterproof agrillaceous sediments at depth from 100 up to 600 m. Ore bodies thickness changes from 5 to 10 m at uranian average-grade 0.03-0.1 %. Width of band shaped ore bodies changes from tens meters to the one kilometers and extent changes from one kilometer up to many tens kilometers. The important feature of deposits is their suitability for development by progressive in situ leaching (ISL) method. It was demonstrated, that uranium ores are comprehensive and, that is important, a lot of commercially important elements, containing in ores, gives in to extraction at development by the ISL method. The preliminary calculation of expenditures for the extraction of useful byproducts from ordinary sulphate solution have demonstrated rather high profitableness for rhenium, scandium, selenium, rare earth even at the very low contents in solution. It was pointed out, that whole technological chain applied now at industrial scale is oriented to mono-metallic uranium ores, therefore present technology of leaching and recovery of industrial solution does not allow ti extract all valuable components containing in ores. The development of new improved technological chain. beginning with a composition of leaching out reagent and up to applying of miscellaneous sorbing materials, can create new mineral-raw base of rare and dissipated elements and to lower considerably the price of uranium mining from sandstone deposits

  3. Alkali control of high-grade metamorphism and granitization

    Directory of Open Access Journals (Sweden)

    Oleg G. Safonov

    2014-09-01

    Full Text Available We review petrologic observations of reaction textures from high-grade rocks that suggest the passage of fluids with variable alkali activities. Development of these reaction textures is accompanied by regular compositional variations in plagioclase, pyroxenes, biotite, amphibole and garnet. The textures are interpreted in terms of exchange and net-transfer reactions controlled by the K and Na activities in the fluids. On the regional scale, these reactions operate in granitized, charnockitized, syenitized etc. shear zones within high-grade complexes. Thermodynamic calculations in simple chemical systems show that changes in mineral assemblages, including the transition from the hydrous to the anhydrous ones, may occur at constant pressure and temperature due only to variations in the H2O and the alkali activities. A simple procedure for estimating the activity of the two major alkali oxides, K2O and Na2O, is implemented in the TWQ software. Examples of calculations are presented for well-documented dehydration zones from South Africa, southern India, and Sri Lanka. The calculations have revealed two end-member regimes of alkalis during specific metamorphic processes: rock buffered, which is characteristic for the precursor rocks containing two feldspars, and fluid-buffered for the precursor rocks without K-feldspar. The observed reaction textures and the results of thermodynamic modeling are compared with the results of available experimental studies on the interaction of the alkali chloride and carbonate-bearing fluids with metamorphic rocks at mid-crustal conditions. The experiments show the complex effect of alkali activities in the fluid phase on the mineral assemblages. Both thermodynamic calculations and experiments closely reproduce paragenetic relations theoretically predicted by D.S. Korzhinskii in the 1940s.

  4. High-resolution sequence stratigraphic character and sandstone-type uranium ore formation. A case from Saihan Formation in Baiyinwula area, Erlian Basin

    International Nuclear Information System (INIS)

    He Zhongbo; Qin Mingkuan

    2006-01-01

    High-resolution sequence stratigraphy has been applied widely in the petroleum exploration and development, many achievements have been achieved. However, it is in the beginning stage that high-resolution sequence stratigraphy is applied to explore the sandstone-type uranium deposits in Erlian Basin. By applying principles of high-resolution sequence stratigraphy and taking typical boreholes as an example, sedimentary cycles of Saihan Formation, the ore-bearing formation in Baiyinwula area are divided and correlated through cross sections. One long-term cycle (LSC 1 ), two middle-term cycles (MSC 1 , MSC 2 ) have been identified in this study. Based on this and combined with the mineralization character of sandstone uranium deposits in this area, it is presented that the interlayer oxidation zone is developed mainly in the rising hemicycle of MSC 1 and uranium ore bodies predominantly in channel sand bodies that were developed in the system tract with low accommodation; furthermore, it is recognized that these sand bodies are moderate (10-15 m) in thickness, fairly good in interconnectivity, relatively thin (<3 m) with the argillaceous interbed, and good in permeability, abundant in the organic matter and thus it is favorable for the development of the interlayer oxidization zone. (authors)

  5. High-grade renal injuries are often isolated in sports-related trauma

    OpenAIRE

    Patel, Darshan P.; Redshaw, Jeffrey D.; Breyer, Benjamin N.; Smith, Thomas G.; Erickson, Bradley A.; Majercik, Sarah D.; Gaither, Thomas W.; Craig, James R.; Gardner, Scott; Presson, Angela P.; Zhang, Chong; Hotaling, James M.; Brant, William O.; Myers, Jeremy B.

    2015-01-01

    © 2015 Elsevier Ltd. All rights reserved. Introduction: Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. Material and methods: We identified patients with AAST grades III...

  6. A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Nagel, W.; Quik, F.

    1993-01-01

    A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

  7. Surface modification and column flotation of a massive ilmenite ore

    International Nuclear Information System (INIS)

    Fan, X.; Rowson, N.A.

    2002-01-01

    The main problems with ilmenite flotation in impeller-type flotation machines are the poor flotation behaviour of ilmenite and the negative effect of slimes. These cause high ilmenite losses in tailings even when a large dosage of fatty acid and fuel oil is consumed. In this study, microwave radiation pre-treatment and ilmenite surface activation were used to modify the surface properties of a massive ilmenite ore sample from Norway to improve ilmenite flotability. A column cell was used to minimize the negative effect of slimes on ilmenite separation efficiency. When ilmenite flotation was performed in a 1 litre Denver cell, the flotation recovery of titanium dioxide from the ilmenite ore sample was only 68.5% (31.1% TiO 2 ) under conventional flotation conditions. After microwave radiation pre-treatment for three minutes at 2600 W and 2.45 GHz, the ferrous ions on ilmenite particle surfaces were converted into ferric ions; hence, the recovery increased from 68.5% to 86.8%. The concentrate grade increased from 31.1% TiO 2 to 32.1% TiO 2 . In ilmenite activation flotation, Pb 2+ ions can be selectively adsorbed on to ilmenite particle surfaces as active sites and therefore enhance the adsorption of oleate ions on ilmenite surfaces. With the addition of 60 g/ton Pb(NO 3 ) 2 , ilmenite flotation recovery increased from 68.5% to 85.1%. However, the quality of ilmenite concentrates was not improved due to the negative effect of slimes. After a two stage cleaning, the grade of ilmenite concentrates was only about 31% TiO 2 . The combination of microwave radiation pre-treatment and the application of a column cell overcame both problems of poor flotability and the negative effect of slimes. When the Denver cell was replaced by a column cell and the massive ilmenite ore sample was pre-treated using microwave radiation for three minutes, the ilmenite concentrate grade increased from 31.1% TiO 2 to 42.9% TiO 2 and the titanium dioxide recovery increased from 68.5% to 90

  8. High bone sialoprotein (BSP expression correlates with increased tumor grade and predicts a poorer prognosis of high-grade glioma patients.

    Directory of Open Access Journals (Sweden)

    Tao Xu

    Full Text Available OBJECTIVES: To investigate the expression and prognostic value of bone sialoprotein (BSP in glioma patients. METHODS: We determined the expression of BSP using real-time RT-PCR and immunohistochemistry in tissue microarrays containing 15 normal brain and 270 glioma samples. Cumulative survival was calculated by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate analyses were performed by the stepwise forward Cox regression model. RESULTS: Both BSP mRNA and protein levels were significantly elevated in high-grade glioma tissues compared with those of normal brain and low-grade glioma tissues, and BSP expression positively correlated with tumor grade (P<0.001. Univariate and multivariate analysis showed high BSP expression was an independent prognostic factor for a shorter progression-free survival (PFS and overall survival (OS in both grade III and grade IV glioma patients [hazard ratio (HR = 2.549 and 3.154 for grade III glioma, and HR = 1.637 and 1.574 for grade IV glioma, respectively]. Patients with low BSP expression had a significantly longer median OS and PFS than those with high BSP expression. Small extent of resection and lineage of astrocyte served as independent risk factors of both shorter PFS and OS in grade III glioma patients; GBM patients without O(6-methylguanine (O(6-meG DNA methyltransferase (MGMT methylation and Karnofsky performance score (KPS less than 70 points were related to poor prognosis. Lack of radiotherapy related to shorter OS but not affect PFS in both grade III and grade IV glioma patients. CONCLUSION: High BSP expression occurs in a significant subset of high-grade glioma patients and predicts a poorer outcome. The study identifies a potentially useful molecular marker for the categorization and targeted therapy of gliomas.

  9. Adjuvant radiotherapy in high-grade extremity sarcomas

    International Nuclear Information System (INIS)

    Franca, Carlos Antonio da Silva; Penna, Antonio Belmiro Rodrigues Campbell; Carvalho, Antonio Carlos Pires; Vieira, Sergio Lannes

    2010-01-01

    Objective: to evaluate the therapies utilized in the authors' institution for management of high-grade extremity sarcomas, analyzing the overall survival rates following multidisciplinary treatment. Materials and methods: retrospective study developed in the period from 1993 to 2007 with 36 patients diagnosed with stages IIb/III, submitted to postoperative external beam radiotherapy, with or without boost dose, utilizing high-dose brachytherapy. Results: thirty-six patients underwent surgery followed by adjuvant external beam radiation therapy. Four patients (11%) received boost dose with brachytherapy, and seven (19%) received chemotherapy. The average dose for radiotherapy was 50 Gy (CI 95%: 47-53 Gy), and the four patients with brachytherapy boost received doses ranging from 16.2 to 35 Gy. Chemotherapy was indicated for seven patients (19%) with positive margins. Fifteen patients (42%) presented local or distant recurrence, and all of them progressed to death. Twenty-one patients (58%) remain with no clinical/radiological evidence of local/distant recurrence. The mean follow-up time was 88 months (IC 95%: 74-102). The overall seven years survival rate was 80%. Conclusion: combined surgery and radiotherapy is an effective treatment with excellent outcomes in cases where brachytherapy is associated, with improved overall survival rates. (author)

  10. Quasi-VMAT in high-grade glioma radiation therapy.

    Science.gov (United States)

    Fadda, G; Massazza, G; Zucca, S; Durzu, S; Meleddu, G; Possanzini, M; Farace, P

    2013-05-01

    To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose < 54 Gy) for a virtual OAR in the form of a 0.5 cm ring around the PTV was investigated. The qVMAT method gave rise to significantly improved PTV95% and conformity index (CI) values in comparison to 3D-CRT (PTV95% = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV95% = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV95% = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example, which have limited departmental

  11. Quasi-VMAT in high-grade glioma radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fadda, G.; Massazza, G.; Zucca, S.; Durzu, S.; Meleddu, G.; Possanzini, M.; Farace, P. [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radio-Oncology

    2013-05-15

    Purpose: To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. Patients and methods: This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose < 54 Gy) for a virtual OAR in the form of a 0.5 cm ring around the PTV was investigated. Results: The qVMAT method gave rise to significantly improved PTV{sub 95%} and conformity index (CI) values in comparison to 3D-CRT (PTV{sub 95%} = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV{sub 95%} = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV{sub 95%} = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. Conclusion: These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example

  12. Quasi-VMAT in high-grade glioma radiation therapy

    International Nuclear Information System (INIS)

    Fadda, G.; Massazza, G.; Zucca, S.; Durzu, S.; Meleddu, G.; Possanzini, M.; Farace, P.

    2013-01-01

    Purpose: To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. Patients and methods: This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose 95% and conformity index (CI) values in comparison to 3D-CRT (PTV 95% = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV 95% = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV 95% = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. Conclusion: These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example, which have limited departmental resources and are not equipped with systems capable of VMAT delivery. (orig.)

  13. Economic outlook for radiometric selection of ores

    International Nuclear Information System (INIS)

    Formery, P.; Ziegler, V.

    1958-01-01

    The value of an ore can be increased by cutting off it's poor fractions. This selection may be realized at two stages: - part of the ore in situ is unable to cover it's extraction and treatment costs, this defines the 'underground cut-off grade'; - another portion of already extracted ore is unable to cover it's transport and treatment costs; this defines the 'surface cut off grade'. These selections are easily feasible owing to the property of uranium ores of emitting gamma radiations. A diagram makes possible a fast forecast on the effect of this selection upon the weight and metal yields. An attempt is made as well in order to provide the expected effect of the composition of underground cut off and surface cut off. This cut off however, being realized through an appreciation of the radiations, involves an alteration of the weight and metal yields which calls for a correction. A survey of the economic interest of the cut-off is done and an example of valorisation in a given deposit of a section at the limit of operability is proposed. (author) [fr

  14. Are the uterine serous carcinomas underdiagnosed? Histomorphologic and immunohistochemical correlates and clinical follow up in high-grade endometrial carcinomas initially diagnosed as high-grade endometrioid carcinoma.

    Science.gov (United States)

    Hu, Shaomin; Hinson, Jeff L; Matnani, Rahul; Cibull, Michael L; Karabakhtsian, Rouzan G

    2018-02-01

    Histologic subclassification of high-grade endometrial carcinomas can sometimes be a diagnostic challenge when based on histomorphology alone. Here we utilized immunohistochemical markers to determine the immunophenotype in histologically ambiguous high-grade endometrial carcinomas that were initially diagnosed as pure or mixed high-grade endometrioid carcinoma, aiming to determine the utility of selected immunohistochemical panel in accurate classification of these distinct tumor types, while correlating these findings with the clinical outcome. A total of 43 high-grade endometrial carcinoma cases initially classified as pure high-grade endometrioid carcinoma (n=32), mixed high-grade endometrioid carcinoma/serous carcinoma (n=9) and mixed high-grade endometrioid carcinoma/clear cell carcinoma (n=2) were retrospectively stained with a panel of immunostains, including antibodies for p53, p16, estrogen receptor, and mammaglobin. Clinical follow-up data were obtained, and stage-to-stage disease outcomes were compared for different tumor types. Based on aberrant staining for p53 and p16, 17/43 (40%) of the high-grade endometrial carcinoma cases initially diagnosed as high-grade endometrioid carcinoma were re-classified as serous carcinoma. All 17 cases showed negative staining for mammaglobin, while estrogen receptor was positive in only 6 (35%) cases. The remaining 26 cases of high-grade endometrioid carcinoma showed wild-type staining for p53 in 25 (96%) cases, patchy staining for p16 in 20 (77%) cases, and were positive for mammaglobin and estrogen receptor in 8 (31%) and 19 (73%) cases, respectively, thus the initial diagnosis of high-grade endometrioid carcinoma was confirmed in these cases. In addition, the patients with re-classified serous carcinoma had advanced clinical stages at diagnosis and poorer overall survival on clinical follow-up compared to that of the remaining 26 high-grade endometrioid carcinoma cases. These results indicate that selected

  15. Examining longitudinal train dynamics in ore car tipplers

    Science.gov (United States)

    Cole, Colin; Spiryagin, Maksym; Bosomworth, Chris

    2017-04-01

    Train simulation has been adapted in this paper to model the behaviour of indexing operations in ore car tippler operations. An important consideration in simulations at these low speeds (less than 4 km/h) is the increased rolling resistance transitioning from stationary conditions to motion. Most formulations of rolling resistance equations do not include this range although there are empirical values in some railway standards. The indexer control utilised here has a target trapezoidal velocity profile. The indexer to train connection was modelled as a stiff linear spring, a damper and a gap element. A sensitivity analysis was completed considering variations in wagon connections including wedge static friction, preload, coupling slack and tippler slack. Track topography including downhill grades of 0.1% and 0.2% and a valley profile were also investigated. Results showed high sensitivity to draft gear parameters of static friction and preload, but minimal benefit from downhill grades and changes in coupling slack.

  16. A novel graded bioactive high adhesion implant coating

    International Nuclear Information System (INIS)

    Brohede, Ulrika; Zhao, Shuxi; Lindberg, Fredrik; Mihranyan, Albert; Forsgren, Johan; Stromme, Maria; Engqvist, Hakan

    2009-01-01

    One method to increase the clinical success rate of metal implants is to increase their bone bonding properties, i.e. to develop a bone bioactive surface leading to reduced risks of interfacial problems. Much research has been devoted to modifying the surface of metals to make them become bioactive. Many of the proposed methods include depositing a coating on the implant. However, there is a risk of coating failure due to low substrate adhesion. This paper describes a method to obtain bioactivity combined with a high coating adhesion via a gradient structure of the coating. Gradient coatings were deposited on Ti (grade 5) using reactive magnetron sputtering with increasing oxygen content. To increase the grain size in the coating, all coatings were post annealed at 385 deg. C. The obtained coating exhibited a gradual transition over 70 nm from crystalline titanium oxide (anatase) at the surface to metallic Ti in the substrate, as shown using cross-section transmission electron microscopy and X-ray photoelectron spectroscopy depth profiling. Using scratch testing, it could be shown that the adhesion to the substrate was well above 1 GPa. The bioactivity of the coating was verified in vitro by the spontaneous formation of hydroxylapatite upon storage in phosphate buffer solution at 37 deg. C for one week. The described process can be applied to implants irrespective of bulk metal in the base and should introduce the possibility to create safer permanent implants like reconstructive devices, dental, or spinal implants.

  17. Benefits of adjuvant chemotherapy in high-grade gliomas.

    Science.gov (United States)

    DeAngelis, Lisa M

    2003-12-01

    The current standard of care for patients with high-grade glioma is resection followed by radiotherapy. Adjuvant chemotherapy is not widely accepted because of the low sensitivity of gliomas to traditional antineoplastic agents, the poor penetration of most drugs across the blood-brain barrier, and the significant systemic toxicity associated with current agents. However, nitrosoureas and, subsequently, temozolomide (Temodar [US], Temodal [international]; Schering-Plough Corporation, Kenilworth, NJ), a novel alkylating agent, cross the blood-brain barrier and have activity against gliomas. Nitrosoureas have been studied in phase III trials in the adjuvant setting. In individual trials, chemotherapy did not increase median survival but did increase the proportion of patients surviving >/=18 months by 15%. Only with large meta-analyses did the addition of chemotherapy achieve a statistically significant improvement in median survival. Currently there is no means of identifying which patients will benefit from adjuvant chemotherapy, but nitrosoureas and temozolomide are well tolerated in most patients, justifying the administration of adjuvant chemotherapy to all newly diagnosed patients with malignant glioma.

  18. Concurrent thermochemoradiotherapy for brain high-grade glioma

    Energy Technology Data Exchange (ETDEWEB)

    Ryabova, A. I., E-mail: ranigor@mail.ru; Novikov, V. A.; Startseva, Zh. A.; Bober, E. E.; Frolova, I. G. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Choinzonov, E. L. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Siberian State Medical University, Tomsk, 634050 (Russian Federation); Gribova, O. V. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Baranova, A. V. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2016-08-02

    Despite the achievements in the current strategies for treatment, the prognosis in malignant glioma patients remains unsatisfactory. Hyperthermia is currently considered to be the most effective and universal modifier of radiotherapy and chemotherapy. Preliminary treatment outcomes for 28 patients with newly diagnosed (23) and recurrent (5) high-grade gliomas were presented. All the patients received multimodality treatment including surgery, thermoche-moradiotherapy followed by 4 cycles of adjuvant chemotherapy. All the patients endured thermochemoradiotherapy well. A complication, limited skin burn (II stage), was diagnosed in two cases and treated conservatively without treatment interruption. A month after thermochemoradiotherapy the results were as follows: complete regression was achieved in 4 cases, partial regression in 4 cases, stable disease in 14 cases and disease progression in 6 cases (one of them is pseudo-progression). After completing the adjuvant chemotherapy 2 more patients demonstrated complete response and 1 patient had disease progression. Introduction of local hyperthermia in multimodal therapy of malignant glioma does not impair the combined modality treatment tolerability of patients with malignant gliomas. A small number of studied patients and short follow-up time do not allow making reliable conclusions about the impact of local hyperthermia on the treatment outcomes; however, there is a tendency towards the increase in disease-free survival in the patients with newly diagnosed malignant gliomas.

  19. High-Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    A more accurate assessment of slab-on-grade foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated).

  20. HPV-genotypes in high-grade intraepithelial cervical lesions in Danish women

    DEFF Research Database (Denmark)

    Kirschner, Benny; Schledermann, Doris; Holl, Katsiaryna

    2013-01-01

    A study was undertaken to assess the distribution of high-risk HPV-genotypes in high-grade cervical intraepithelial neoplastic lesions in Danish women.......A study was undertaken to assess the distribution of high-risk HPV-genotypes in high-grade cervical intraepithelial neoplastic lesions in Danish women....

  1. Trace-element and multi-isotope geochemistry of Late-Archean black shales in the Carajas iron-ore district, Brazil

    DEFF Research Database (Denmark)

    Cabral, A. R.; Creaser, R. A.; Naegler, T.

    2013-01-01

    The 250-300-m-thick Carajas Formation in the Carajas mineral province, northern Brazil, consists of banded iron formation (including giant high-grade iron-ore deposits) and minor black shale, overlying a thick pile (2-3 km) of about 2.75-Ga-old metabasalt. Carbonaceous shale with pyrite-and local...

  2. Prognostic significance of multiple kallikreins in high-grade astrocytoma

    International Nuclear Information System (INIS)

    Drucker, Kristen L.; Gianinni, Caterina; Decker, Paul A.; Diamandis, Eleftherios P.; Scarisbrick, Isobel A.

    2015-01-01

    Kallikreins have clinical value as prognostic markers in a subset of malignancies examined to date, including kallikrein 3 (prostate specific antigen) in prostate cancer. We previously demonstrated that kallikrein 6 is expressed at higher levels in grade IV compared to grade III astrocytoma and is associated with reduced survival of GBM patients. In this study we determined KLK1, KLK6, KLK7, KLK8, KLK9 and KLK10 protein expression in two independent tissue microarrays containing 60 grade IV and 8 grade III astrocytoma samples. Scores for staining intensity, percent of tumor stained and immunoreactivity scores (IR, product of intensity and percent) were determined and analyzed for correlation with patient survival. Grade IV glioma was associated with higher levels of kallikrein-immunostaining compared to grade III specimens. Univariable Cox proportional hazards regression analysis demonstrated that elevated KLK6- or KLK7-IR was associated with poor patient prognosis. In addition, an increased percent of tumor immunoreactive for KLK6 or KLK9 was associated with decreased survival in grade IV patients. Kaplan-Meier survival analysis indicated that patients with KLK6-IR < 10, KLK6 percent tumor core stained < 3, or KLK7-IR < 9 had a significantly improved survival. Multivariable analysis indicated that the significance of these parameters was maintained even after adjusting for gender and performance score. These data suggest that elevations in glioblastoma KLK6, KLK7 and KLK9 protein have utility as prognostic markers of patient survival. The online version of this article (doi:10.1186/s12885-015-1566-5) contains supplementary material, which is available to authorized users

  3. Primary balloon angioplasty for symptomatic, high-grade intracranial stenosis.

    Science.gov (United States)

    Tomycz, Luke; Bansal, Neil K; Lockney, Tim; Strothers, Megan; Connors, John J; Shay, Scott; Singer, Robert J

    2013-01-01

    In light of recent controversy about the safety and efficacy of intracranial stenting, we sought to evaluate our experience with primary balloon angioplasty for symptomatic, high-grade intracranial stenosis. All intracranial angioplasty cases performed at Vanderbilt University Medical Center from 2006 to 2011 were retrospectively reviewed for degree of stenosis pre- and post-procedure. Immediate peri-procedural complications were evaluated as well as one-month and long-term outcomes. A total of 26 patients were included in the study with a mean age of 63.0 years and a mean follow-up of 350.2 days. The average pre-procedure stenosis was 71.2%. The immediate, average post-procedure stenosis was 46.6%, and the average post-procedure stenosis at last angiographic follow-up was 44.5%. Retreatment was required in only 3.8% of patients. The primary end-point of major stroke or death at 30 days was observed in 11.5%, and the overall intra-procedural complication rate was 7.7%. The incidence of stroke or death at last follow-up was 15.4%, which is comparable to the one-year stroke or death rate in the medical arm of the SAMPRISS trial. In this retrospective series, primary balloon angioplasty was found to be effective as a treatment option for symptomatic intracranial stenosis with the risk of stroke or death at 30 days higher than the medical arm of SAMPRIS but lower than the stenting arm. The one-year risk of stroke was comparable to that reported for the one-year outcomes in the SAMPRISS medical arm.

  4. Direct Reduction of Iron Ore

    Science.gov (United States)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  5. Sampling of ore

    International Nuclear Information System (INIS)

    Boehme, R.C.; Nicholas, B.L.

    1987-01-01

    This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

  6. The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit

    Directory of Open Access Journals (Sweden)

    Seyyed Ali Nezamolhosseini

    2017-01-01

    Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone.  Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.

  7. Introduction to ore geology

    International Nuclear Information System (INIS)

    Evans, A.M.

    1987-01-01

    This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint

  8. Predicting Factors for High-Grade Cervical Dysplasia in Women With Low-Grade Cervical Cytology and Nonvisible Squamocolumnar Junction.

    Science.gov (United States)

    Bogani, Giorgio; Taverna, Francesca; Lombardo, Claudia; Ditto, Antonino; Martinelli, Fabio; Signorelli, Mauro; Chiappa, Valentina; Leone Roberti Maggiore, U; Mosca, Lavinia; Sabatucci, Ilaria; Scaffa, Cono; Lorusso, Domenica; Raspagliesi, Francesco

    2018-01-01

    To assess the risk of developing high-grade cervical dysplasia among women with low-grade cervical cytology and nonvisible squamocolumnar junction (SCJ) at colposcopic examination. Data of consecutive women with low-grade intraepithelial lesion(≤LSIL) undergoing colposcopic examination, which was unsatisfactory (due to the lack of the visualization of the entire SCJ), were retrospectively reviewed. The risk of developing high-grade cervical intraepithelial neoplasia (CIN2+) was assessed using Kaplan-Meier and Cox models. Data of 86 women were retrieved. Mean (standard deviation [SD]) age was 36.3 (13.4) years. A total of 71 (82.5%) patients had high-risk human papillomavirus (HR-HPV) at the time of diagnosis. Among the 63 patients undergoing repetition of HPV testing, 15 (24%) and 48 (76%) women had positive and negative tests for HR-HPV at 12 months, respectively. We observed that 5 (33%) of 15 patients with HPV persistence developed CIN2+, while only 1 (2%) patient of 48 patients without HPV persistence developed CIN2+ (odds ratio [OR]: 23.5; 95% confidence interval [CI]: 2.46-223.7; P < .001). The length of HR-HPV persistence correlated with an increased risk of developing CIN2+ ( P < .001; P for trend). High-risk HPV persistence is the only factor predicting for CIN2+ (hazard ratio: 3.19; 95% CI: 1.55-6.57; P = .002). High-risk HPV persistence predicts the risk of developing CIN2+ in patients with unsatisfactory colposcopic examination. Further studies are warranted in order to implement the use of HPV testing in patients with unsatisfactory colposcopy.

  9. Medical and endoscopic management of high-grade dysplasia in Barrett's esophagus

    NARCIS (Netherlands)

    Wang, K. K.; Tian, J. M.; Gorospe, E.; Penfield, J.; Prasad, G.; Goddard, T.; WongKeeSong, M.; Buttar, N. S.; Lutzke, L.; Krishnadath, S.

    2012-01-01

    The management of high-grade dysplasia in Barrett's esophagus has clearly changed over recent years. The risk of cancer development is still substantial, with about one in three patients developing cancer, but a number of patients do not develop cancer. The nature of high-grade dysplasia has also

  10. Preliminary stop of the TOPical Imiquimod treatment of high-grade Cervical intraepithelial neoplasia (TOPIC) trial

    NARCIS (Netherlands)

    Koeneman, M. M.; Kruse, Arnold-Jan; Kooreman, L. F. S.; zur Hausen, Axel; Hopman, Anton H N; Sep, S. J. S.; Van Gorp, T.; Slangen, B. F. M.; van Beekhuizen, H. J.; de Sande, Michiel A. J. van; Gerestein, Cornelis G.; Nijman, H. W.; Kruitwagen, R. F. M. P.

    2017-01-01

    The "TOPical Imiquimod treatment of high-grade Cervical intraepithelial neoplasia" (TOPIC) trial was stopped preliminary, due to lagging inclusions. This study aimed to evaluate the treatment efficacy and clinical applicability of imiquimod 5% cream in high-grade cervical intraepithelial neoplasia

  11. High Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    ?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

  12. Characterization of Sumbawa manganese ore and recovery of manganese sulfate as leaching products

    Science.gov (United States)

    Kusumaningrum, Retno; Rahmani, Siti Astari; Widayatno, Wahyu Bambang; Wismogroho, Agus Sukarto; Nugroho, Dwi Wahyu; Maulana, Syahrizal; Rochman, Nurul Taufiqu; Amal, M. Ikhlasul

    2018-05-01

    The aims of this research were to study the leaching process of manganese ore which originated from Sumbawa, Indonesia and its characterization. A high grade Indonesian manganese ore from Sumbawa, West of Nusa Tenggara was characterized by X-Ray Fluorescence (XRF). The result showed composition of 78.8 % Mn, 17.77% Fe and the rest were trace elements such as Si, Co, Ti, Zn, V and Zr contents. X-Ray Diffraction analysis showed that the manganese ore was consisted of pyrolusite (MnO2), rhodonite (MnSiO3), rhodochrosite (MnCO3) and hematite (Fe2O3). Manganese ore was also analyzed by thermal analysis to observe their thermal decomposition character. In this study, sulphuric acid (H2SO4, 6 M) was deployed as leaching agent. The leaching process was performed at 90 °C for two hours with the addition of NH4OH to control pH. Recovery percentage of leaching process yielded of 87 % Mn extracted. The crystallization process result at heating temperature of 200 °C was confirmed by XRD as manganese sulfate.

  13. A laboratory study to evaluate the possibility of sulphur and phosphorous removal from iron ore concentrate by leaching

    Directory of Open Access Journals (Sweden)

    Pour Hassan Rezvani

    2016-01-01

    Full Text Available Iron ore concentrates with high grade sulfur cause several problems in the steel making process, and hence affect the concentrate price. Environmental issues such as sulfur dioxide emission during the concentrate pelletizing process and effect on the steel quality are other issues. The current study was focused on removal of sulfur from the iron ore concentrate by using the chemical leaching technique. The magnetite iron ore concentrate was chosen for this purpose. The results obtained showed that more than 90% of the total sulfur content was removed from the iron ore concentrate by chemical leaching. Effects of several parameters such as temperature, particle size and use of organic solvent on sulfur removal were investigated by a series of experiments. After optimizing the experimental conditions, it was demonstrated that with addition of sulfur, phosphorus, another important impurity was also removed from the iron ore concentrate. In addition, one of the major advantages of our proposed method was transformation of mineral pyrites to useful by-products such as elemental sulfur.

  14. Practice of the counter-current trickle leaching of uranium ore by refreshed liquor of bacterial oxidation

    International Nuclear Information System (INIS)

    Chen Shian; Huang Xiangfu; Fan Baotuan

    1995-01-01

    The uranium ore of the Mine No. 753 is a high-silicate type primary one, in which the tetravalent uranium accounts for 85%, and the uranium grade is in the range of 0.36% to 0.442%. To reduce the engineering investment and the operating cost a four-stage counter-current trickle leaching pilot-plant test was carried out with the leaching time 50 days and acid consumption 38 kg per ton of ore, and the recovery of more than 95% was obtained. Using the counter-current trickle leaching mode and controlling the limit concentration of the harmful matters in the bacterial leaching liquor, the latter can be effectively oxidized by the synchronical regeneration. A trickle leaching comparative test of 25 ton ore single heap also gave a good result of more than 95% in extraction rate, and 30% acid consumption was saved and the 2.0% pyrolusite (containing MnO 2 40%) was eliminated. This process is feasible in technology and worth-while in economy for treating the uranium ore of Mine No. 753, and provides a new method of uranium ore trickle leaching

  15. Study on the pre-treatment of oxidized zinc ore prior to flotation

    Science.gov (United States)

    He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

    2018-02-01

    The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

  16. The performance of leaching and bio-leaching from sulphide ores usiing SEVOP

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeov, Blagoj; Golomeova, Mirjana; Sala, Ferat; Gocev, Zivko; Zivanovic, Jordan; Krstev, Dejan

    2013-01-01

    The refractory or low grade copper chalcopyrite ores or galena/sphalerite domestic ores in Republic of Macedonia are investigated by conventional copper flotation and selective flotation for galena/sphalerite. In the meantime, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer programme. Multisimple...

  17. Analysis of Characteristics of Ore about Iron Deposit of Da Hong Mountain in Yun Nan Province

    Directory of Open Access Journals (Sweden)

    Zhang Yuefeng

    2016-01-01

    Full Text Available This thesis aims to analyse the deposit characteristics about Da Hong Mountains Iron ore in Yunnan province. The texture and structure, especially the chemical composition, is different in every section of deposit after comparing. Moreover, the content of SiO2 is much higher than general iron ore. However, the content of other noble metals cannot reach the lowest industrial grade. Da Hong Mountains Iron ore has unique features because of metallogenic periods.

  18. PA03.13. Effect of triphaladi rasayana along with yoga therapy on low grade non hodgkins lymphoma and resistant intermediate and high grade non hodgkins lymphoma

    Science.gov (United States)

    Soumya, MS Surya; Sarasa, TP

    2013-01-01

    Purpose: 1. To find out the effect of Thriphaladi Rasayana along with Yoga Therapy on low grade Non Hodgkins Lymphoma and resistant intermediate and high grade NonHodgkins Lymphoma. 2. To apply a less costly, less morbid, well accepted method of treatment on NHL. 3.To find a simple method to increase the immunity. 4.To try a drug which is easy to prepare? Method: Purposive sampling technique was used for the study. Sample of 30 patients age range 25 75 years with histologicaly proven NonHodgkins lymphoma, attending the M.O.I.O.P of the regional cancer centre during a period of 18 months. Groups1) Low grade NonHodgkins Lymphoma 2) Resistant intermediate &High grade NonHodgkins lymphoma (failed chemotherapy) were taken. Procedure : 2 groups were given Triphaladhi Rasayana (15 grams of powder with ghee and honey) twice dailymorning& at bed time with milk as anupana for period of 1month along with selected yoga asanas and niyama? Result: Symptoms included were fever, night sweats, weight loss, lymph nodes enlargement, splenomegaly, and hepatomegaly. In low grade symptom relief was noted in almost all cases. Lymph node changes notedLow grade5 2% (complete remission), 38% (partial remission), 10% (no change), intermediate35% (CR), 52% (PR) & 13% (NC), High grade67% (CR), 33%(PR). Hepatomegaly changes :ve in low grade92.86%, intermediate 90.9% & high grade100%. Splenomegaly changes :ve in low grade92.86%, intermediate72.72% & high grade80% Over all remission status of 30 patientscomplete remission30%, partial remission 30% & no change30%? Conclusion: Thriphaladirasayana along with Yoga therapy is very effective in Low grade NonHodgkins lymphoma and resistant intermediate and high grade Non hodgkins Lymphoma?

  19. A graded d-spacing multilayer telescope for high-energy x-ray astronomy

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; WESTERGAARD, NJ

    1992-01-01

    A high energy telescope design is presented which combines grazing incidence geometry with Bragg reflection in a graded d-spacing multilayer coating to obtain significant sensitivity up to --6O keV. The concept utilizes total reflection and first order Bragg reflection in a graded d-spacing multi...

  20. High-Grade Hydronephrosis Predicts Poor Outcomes After Radical Cystectomy in Patients with Bladder Cancer

    Science.gov (United States)

    Kim, Dong Suk; Cho, Kang Su; Lee, Young Hoon; Cho, Nam Hoon; Oh, Young Taek

    2010-01-01

    We examined whether the presence and severity of preoperative hydronephrosis have prognostic significance in patients who underwent radical cystectomy for transitional cell carcinoma of the bladder. The medical records of 457 patients who underwent radical cystectomy for bladder cancer between 1986 and 2005 were retrospectively reviewed. Following the Society for Fetal Urology grading system, patients were divided into low-, and high-grade hydronephrosis groups. Clinicopathologic factors associated with preoperative hydronephrosis and survival were evaluated. Of a total of 406 patients, unilateral hydronephrosis was found in 74 (18.2%), bilateral hydronephrosis in 11 (2.7%), and no hydronephoris in 321 (79.1%). Low-grade hydronephrosis was found in 57 (12.2%) patients and high-grade hydronephrosis in 28 (6%). Preoperative hydronephrosis was related to higher pT stage and lymph node invasion. In univariate analysis, the presence of hydronephrosis, hydronephrosis grade, age, pT and pN stage, tumor grade, surgical margin, number of retrieved nodes, carcinoma in situ, and lymphovascular invasion were significant prognostic factors for cancer-specific survival. In multivariate analysis, bilateral hydronephrosis and high-grade hydronephrosis remained significant predictors for decreased survival. The presence of preoperative hydronephrosis, and high-grade hydronephrosis are significant prognostic factors in patients with bladder cancer after radical cystectomy. PMID:20191034

  1. Preparation of high purification and food grade phosphoric acid from technical grade phosphoric acid by liquid-liquid detraction method

    International Nuclear Information System (INIS)

    Alimoradi, M.; Borji, F.; Kishani, A.

    2002-01-01

    Pay attention to increasing consumption of high purification and food grade phosphoric acid in various industries and food industries and on in on hand and lack of preparation between production and distribution of this products its purification is so vital. In this article of liquid-liquid extraction method with normal hexane-mixture of ammonia and acetone-diisopropyl alcohol and normal butanol solvents and these determination of distribution coefficient each one with ph-me try titration we can evaluate effectiveness and sufficiency each one. Because of proper coefficient distribution and its local production of normal butanol solvent and low price is the best solvent. To phosphoric acid modifying coefficient distribution for extraction of phosphoric acid we can add a little value sulfuric acid to the mixture and to remove flouride impurity we add a little Na 2 O. After extraction stage extracted phosphoric acid in the normal strips by evaluating with distilled water and then by passing the carbon active bed and following passes of cationic resine column and concentrated with vacuum distillation. Conclusion of this article is produce of phosphoric acid 85% w/w and food grade from impure phosphoric acid 52% w/w with technical grade

  2. Uranium ore processing in Spain

    International Nuclear Information System (INIS)

    Josa, J.M.

    1976-01-01

    The paper presents a review of the Spanish needs of uranium concentrates and uranium ore processing technology and trends in Spain. Spain produces approximately 200t U 3 O 8 /a at two facilities. One plant in the south (Andujar, Jaen) can obtain 70t U 3 O 8 /a and uses a conventional acid leaching process with countercurrent solvent extraction. A second plant, situated in the west (Ciudad Rodrigo, Salamanca) has started in 1975 and has a capacity of 120-130t U 3 O 8 /a, using acid heap leaching and solvent extraction. There is another experimental facility (Don Benito, Badajoz) scheduled to start in 1976 and expected to produce about 25-35t U 3 O 8 /a as a by-product of the research work. For the near future (1978) it is hoped to increase the production with: (a) A new conventional acid leaching/solvent extraction plant in Ciudad Rodrigo; its tentative capacity is fixed at 550t U 3 O 8 /a. (b) A facility in the south, to recover about 130t U 3 O 8 /a from phosphoric acid. (c) Several small mobile plants (30t U 3 O 8 /a per plant); these will be placed near small and isolated mines. The next production increase (1979-1980) will come with the treatment of sandstones (Guadalajara and Cataluna) and lignites(Cataluna); this is being studied. There are also research programmes to study the recovery of uranium from low-grade ores (heap, in-situ and bacterial leaching) and from other industries. (author)

  3. Differentiation of low- and high-grade clear cell renal cell carcinoma: Tumor size versus CT perfusion parameters.

    Science.gov (United States)

    Chen, Chao; Kang, Qinqin; Xu, Bing; Guo, Hairuo; Wei, Qiang; Wang, Tiegong; Ye, Hui; Wu, Xinhuai

    To compare the utility of tumor size and CT perfusion parameters for differentiation of low- and high-grade clear cell renal cell carcinoma (RCC). Tumor size, Equivalent blood volume (Equiv BV), permeability surface-area product (PS), blood flow (BF), and Fuhrman pathological grading of clear cell RCC were retrospectively analyzed. High-grade clear cell RCC had significantly higher tumor size and lower PS than low grade. Tumor size positively correlated with Fuhrman grade, but PS negatively did. Tumor size and PS were significantly independent indexes for differentiating high-grade from low-grade clear cell RCC. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Diffusion Profiling via a Histogram Approach Distinguishes Low-grade from High-grade Meningiomas, Can Reflect the Respective Proliferative Potential and Progesterone Receptor Status.

    Science.gov (United States)

    Gihr, Georg Alexander; Horvath-Rizea, Diana; Garnov, Nikita; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Henkes, Hans; Meyer, Hans Jonas; Hoffmann, Karl-Titus; Surov, Alexey; Schob, Stefan

    2018-02-01

    Presurgical grading, estimation of growth kinetics, and other prognostic factors are becoming increasingly important for selecting the best therapeutic approach for meningioma patients. Diffusion-weighted imaging (DWI) provides microstructural information and reflects tumor biology. A novel DWI approach, histogram profiling of apparent diffusion coefficient (ADC) volumes, provides more distinct information than conventional DWI. Therefore, our study investigated whether ADC histogram profiling distinguishes low-grade from high-grade lesions and reflects Ki-67 expression and progesterone receptor status. Pretreatment ADC volumes of 37 meningioma patients (28 low-grade, 9 high-grade) were used for histogram profiling. WHO grade, Ki-67 expression, and progesterone receptor status were evaluated. Comparative and correlative statistics investigating the association between histogram profiling and neuropathology were performed. The entire ADC profile (p10, p25, p75, p90, mean, median) was significantly lower in high-grade versus low-grade meningiomas. The lower percentiles, mean, and modus showed significant correlations with Ki-67 expression. Skewness and entropy of the ADC volumes were significantly associated with progesterone receptor status and Ki-67 expression. ROC analysis revealed entropy to be the most accurate parameter distinguishing low-grade from high-grade meningiomas. ADC histogram profiling provides a distinct set of parameters, which help differentiate low-grade versus high-grade meningiomas. Also, histogram metrics correlate significantly with histological surrogates of the respective proliferative potential. More specifically, entropy revealed to be the most promising imaging biomarker for presurgical grading. Both, entropy and skewness were significantly associated with progesterone receptor status and Ki-67 expression and therefore should be investigated further as predictors for prognostically relevant tumor biological features. Since absolute ADC

  5. Comparison of oxidants in alkaline leaching of uranium ore

    International Nuclear Information System (INIS)

    Sreenivas, T.; Rajan, K.C.; Srinivas, K.; Anand Rao, K.; Manmadha Rao, M.; Venkatakrishnan, R.R.; Padmanabhan, N.P.H.

    2007-01-01

    The uranium minerals occurring in various ore deposits consists of predominantly uranous ion (U +4 ), necessitating use of an oxidant and other lixiviants for efficient dissolution during leaching. Unlike acid leaching route, where uranium minerals dissolution could be achieved efficiently with cheaper lixiviants, processing of ores by alkaline leaching route involve expensive lixiviants and drastic leaching conditions. Alkaline leaching of uranium ores becomes economical only upon using cheaper and efficient oxidants and conservation of other reagents by their recycle. The present paper gives efficacy of various oxidants - KMnO 4 , NaOCl, Cu - NH 3 , air and oxygen, in the leaching of uranium from a low-grade dolostone hosted uranium ore of India. A comparison based on technical merits and cost of the oxidant chemicals is discussed. (author)

  6. CIP2A protein expression in high-grade, high-stage bladder cancer

    International Nuclear Information System (INIS)

    Huang, Lisa P; Savoly, Diana; Sidi, Abraham A; Adelson, Martin E; Mordechai, Eli; Trama, Jason P

    2012-01-01

    Bladder cancer is one of the most common cancers in the United States. Numerous markers have been evaluated for suitability of bladder cancer detection and surveillance. However, few of them are acceptable as a routine tool. Therefore, there exists a continuing need for an assay that detects the presence of bladder cancer in humans. It would be advantageous to develop an assay with a protein that is associated with the development of bladder cancer. We have identified the cancerous inhibitor of PP2A (CIP2A) protein as a novel bladder cancer biomarker. In this study, Western blot analysis was used to assess the expression level of CIP2A protein in bladder cancer cell lines and bladder cancer patient tissues (n = 43). Our studies indicated CIP2A protein was abundantly expressed in bladder cancer cell lines but not in nontumor epithelial cell lines. Furthermore, CIP2A was specifically expressed in transitional cell carcinoma (TCC) of the bladder tumor tissues but not in adjacent nontumor bladder tissue. Our data showed that CIP2A protein detection in high-grade TCC tissues had a sensitivity of 65%, which is 3.4-fold higher than that seen in low-grade TCC tissues (19%). The level of CIP2A protein expression increased with the stage of disease (12%, 27%, 67%, and 100% for pTa, pT1, pT2, and pT3 tumor, respectively). In conclusion, our studies suggest that CIP2A protein is specifically expressed in human bladder tumors. CIP2A is preferentially expressed in high-grade and high-stage TCC tumors, which are high-risk and invasive tumors. Our studies reported here support the role of CIP2A in bladder cancer progression and its usefulness for the surveillance of recurrence or progression of human bladder cancer

  7. Undifferentiated pleomorphic sarcoma: indolent, tail-like recurrence of a high-grade tumor

    Energy Technology Data Exchange (ETDEWEB)

    Alpert, Justin S. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Boland, Patrick [Memorial Sloan Kettering Cancer Center, Division of Orthopaedic Surgery, Department of Surgery, New York, NY (United States); Weill Medical College of Cornell University, New York, NY (United States); Hameed, Meera [Memorial Sloan Kettering Cancer Center, Department of Pathology, New York, NY (United States); Panicek, David M. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Weill Medical College of Cornell University, New York, NY (United States)

    2018-01-15

    Recurrence of a soft tissue sarcoma typically manifests as a round or oval mass at imaging, and recurrent high-grade soft tissue sarcomas generally enlarge relatively rapidly. We present a case of high-grade undifferentiated pleomorphic sarcoma in the calf of a 48-year-old male that recurred as a thin, curvilinear ''tail'' of enhancing tissue at magnetic resonance imaging (MRI), with extremely indolent growth over a 7-year period. The unusual imaging finding of a slowly enlarging ''tail'' should not be dismissed as postoperative changes, even for a high-grade soft tissue sarcoma. (orig.)

  8. High-grade myxofibrosarcoma-presented as a large mass of right upper arm

    Directory of Open Access Journals (Sweden)

    Sunil Vitthalrao Jagtap

    2015-01-01

    Full Text Available Myxofibrosarcoma is one of the rare soft tissue sarcomas. We present a case of a 65-year-old male having large soft tissue mass over right upper arm associated with surface ulceration. On histopathological study tumor was diagnosed as myxofibrosarcoma - high grade according to modified FNCLCC grading system. Like many other tumors of connective tissue, soft tissue sarcoma exhibits high recurrence. In our case, tumor showed features of high grade with local recurrence, large size; however, no evidence of metastasis was noted. For this unpredictable clinical behavior, we are presenting this case.

  9. Classifying low-grade and high-grade bladder cancer using label-free serum surface-enhanced Raman spectroscopy and support vector machine

    Science.gov (United States)

    Zhang, Yanjiao; Lai, Xiaoping; Zeng, Qiuyao; Li, Linfang; Lin, Lin; Li, Shaoxin; Liu, Zhiming; Su, Chengkang; Qi, Minni; Guo, Zhouyi

    2018-03-01

    This study aims to classify low-grade and high-grade bladder cancer (BC) patients using serum surface-enhanced Raman scattering (SERS) spectra and support vector machine (SVM) algorithms. Serum SERS spectra are acquired from 88 serum samples with silver nanoparticles as the SERS-active substrate. Diagnostic accuracies of 96.4% and 95.4% are obtained when differentiating the serum SERS spectra of all BC patients versus normal subjects and low-grade versus high-grade BC patients, respectively, with optimal SVM classifier models. This study demonstrates that the serum SERS technique combined with SVM has great potential to noninvasively detect and classify high-grade and low-grade BC patients.

  10. Malignant Subdural Hematoma Associated with High-Grade Meningioma

    Science.gov (United States)

    Teramoto, Shinichiro; Tsunoda, Akira; Kawamura, Kaito; Sugiyama, Natsuki; Saito, Rikizo; Maruki, Chikashi

    2018-01-01

    A 70-year-old man, who had previously undergone surgical resection of left parasagittal meningioma involving the middle third of the superior sagittal sinus (SSS) two times, presented with recurrence of the tumor. We performed removal of the tumor combined with SSS resection as Simpson grade II. After tumor removal, since a left dominant bilateral chronic subdural hematoma (CSDH) appeared, it was treated by burr hole surgery. However, because the CSDH rapidly and repeatedly recurred and eventually changed to acute subdural hematoma, elimination of the hematoma with craniotomy was accomplished. The patient unfortunately died of worsening of general condition despite aggressive treatment. Histopathology of brain autopsy showed invasion of anaplastic meningioma cells spreading to the whole outer membrane of the subdural hematoma. Subdural hematoma is less commonly associated with meningioma. Our case indicates the possibility that subdural hematoma associated with meningioma is formed by a different mechanism from those reported previously. PMID:29896565

  11. Technology development for recovery of individual rare earth elements at high purity from Dong-Pao rare earth concentrated ore of Vietnam

    International Nuclear Information System (INIS)

    Hoang Nhuan; Le Ba Thuan; Luu Xuan Dinh; Tran Hoang Mai; Tran Thi Hong Thai; Yoshiuyki Aiba; Hiroaki Nishimura

    2015-01-01

    In this work, the research results on RE processing process at laboratory scale and pilot scale was reported and discussed. Experimental research on thermal decomposition and sulfate process of bastnaesite ore with sulfuric acid in electric furnace was carried out, the different roasting conditions, mass transfer rate, reactions and RE and/or non-RE behaviors during roasting and leaching were investigated. The roasting temperatures were 450"oC and 550"oC. With higher roasting temperature and longer roasting time, the RE recovery yield reduced. The RE recovery yield reached the highest (over 94%) at roasting temperature of 550"oC for 2 hrs. The different extracting conditions for separation of REEs were investigated in laboratory scale as well as pilot scale. At pilot scale, the separation of REEs was performed on 120-stage extraction system produced by Japan, using PC88A solvent dissolved in IP2028. The volume of each stage was 20 L. The results showed that REEs were separated from RE resource of Vietnam and individual RE elements such as La, Ce, Pr, and Nd were obtained at high purity. The parameters for each extraction stage were reported in this work. The results indicated that in order to obtain highly purified Nd (>99%), it needs to use an extraction system with higher stage number, about 200 stages. The extraction data at pilot scale of this investigation was used as basic data for calculating parameters for extraction system in industrial scale. (author)

  12. Treatment of bastnaesite ore from Vietnamese Socialist Republic

    International Nuclear Information System (INIS)

    Formanek, J.; Jerabek, J.; Jancarek, J.

    1987-01-01

    From the Vietnamese deposit at Nam Nam Xe Czechoslovakia imported several hundred tons of ore. Several methods of ore dressing were used: gravitational, preconcentration in electromagnetic field, magnetic separation, high-intesity electromagnetic separation. Flotation evidently was the best dressing method tried. The results are presented of testing using different flotation agents. (E.S.)

  13. Geochemistry and ore prospecting

    International Nuclear Information System (INIS)

    Le Caignec, R.

    1954-01-01

    Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author) [fr

  14. Radiometric sorting of Rio Algom uranium ore

    International Nuclear Information System (INIS)

    Cristovici, M.A.

    1983-11-01

    An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content ( 2 (2 counts/in 2 ) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm 2 (5-6 counts/in 2 ) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

  15. The recovery of a concentrate of tin and tungsten from ore mined at Van Roois Vley

    International Nuclear Information System (INIS)

    Guest, R.N.

    1985-01-01

    Concentration tests using gravity separation, flotation, and magnetic separation showed that it is possible for the high-grade ore mined at Van Roois Vley to be upgraded to a concentrate containing 61 per cent Sn-Wo 3 at a recovery of about 80 per cent, and for the low-grade ore to be upgraded to 53 per cent Sn-WO 3 at the same recovery. However, it is suggested that, under normal mining conditions and with large-scale mining equipment, less fines would be produced and this should lead to an increase in grade and recovery. Mineralogical examinations showed that intermediate fractions produced by tabling contained very few locked particles, and that the grade of the final concentrate on a full-scale plant would probably be higher than that obtained with laboratory equipment. Molybdenite could be a valuable byproduct, but flotation tests of gravity concentrates for selective recovery of the mineral gave variable results. Flotation tests for the removal of fluorspar from the final concentrate were unsuccessful

  16. New age radiometric ore sorting - the elegant solution

    International Nuclear Information System (INIS)

    Gordon, H.P.; Heuer, T.

    2000-01-01

    Radiometric ore sorting technology and application are described in two parts. Part I reviews the history of radiometric sorting in the minerals industry and describes the latest developments in radiometric sorting technology. Part II describes the history, feasibility study and approach used in the application of the new technology at Rossing Uranium Limited. There has been little progress in the field of radiometric sorting since the late 1970s. This has changed with the development of a high capacity radiometric sorter designed to operate on low-grade ore in the +75mm / -300mm size fraction. This has been designed specifically for an application at Rossing. Rossing has a long history in radiometric sorting dating back to 1968 when initial tests were conducted on the Rossing prospect. Past feasibility studies concluded that radiometric sorting would not conclusively reduce the unit cost of production unless sorting was used to increase production levels. The current feasibility study shows that the application of new radiometric sorter technology makes sorting viable without increasing production, and significantly more attractive with increased production. A pilot approach to confirm sorter performance is described. (author)

  17. Effective Processing of the Iron Ores

    Science.gov (United States)

    Kuskov, Vadim; Kuskova, Yana; Udovitsky, Vladimir

    2017-11-01

    Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats): comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

  18. Effective Processing of the Iron Ores

    Directory of Open Access Journals (Sweden)

    Kuskov Vadim

    2017-01-01

    Full Text Available Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats: comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

  19. High-grade ovarian cancer secreting effective exosomes in tumor angiogenesis.

    Science.gov (United States)

    Yi, Huan; Ye, Jun; Yang, Xiao-Mei; Zhang, Li-Wen; Zhang, Zhi-Gang; Chen, Ya-Ping

    2015-01-01

    Ovarian cancer, the most lethal gynecological cancer, related closely to tumor stage. High-grade ovarian cancer always results in a late diagnose and high recurrence, which reduce survival within five years. Until recently, curable therapy is still under research and anti-angiogenesis proves a promising way. Tumor-derived exosomes are essential in tumor migration and metastases such as angiogenesis is enhanced by exosomes. In our study, we have made comparison between high-grade and unlikely high-grade serous ovarian cancer cells on exosomal function of endothelial cells proliferation, migration and tube formation. Exosomes derived from high-grade ovarian cancer have a profound impact on angiogenesis with comparison to unlikely high-grade ovarian cancer. Proteomic profiles revealed some potential proteins involved in exosomal function of angiogenesis such as ATF2, MTA1, ROCK1/2 and so on. Therefore, exosomes plays an influential role in angiogenesis in ovarian serous cancer and also function more effectively in high-grade ovarian cancer cells.

  20. [High-grade pressure sores in frail older high-risk persons. A retrospective postmortem case-control-study].

    Science.gov (United States)

    Von Renteln-Kruse, W; Krause, T; Anders, J; Kühl, M; Heinemann, A; Püschel, K

    2004-04-01

    Some old persons at risk do develop, but others, at comparable risk, do not develop high-grade pressure sores. To evaluate potentially different risk factors, we performed a post mortem case-control study in old persons who developed high-grade pressure sores within six months until 14 days before death. Consecutive cases with pressure sores grade >/=3 and potential controls at comparably high risk for pressure sores were examined before cremation. After written informed consent had been obtained by the next relatives, all available nursing and medical records of the deceased were thoroughly evaluated. Cases and controls were matched according to age, gender, immobility, and cachexia.A total of 100 cases with 71 pressure sores grade 3 and 29 pressure sores grade 4 were compared to 100 controls with 27 pressure sores grade pressure sores in frail older high-risk persons. Sedative drug effects and impaired patient compliance with preventive and therapeutic measures may also be associated with the development of high-grade pressure sores in old persons at high risk.

  1. ADAR2 editing activity in newly diagnosed versus relapsed pediatric high-grade astrocytomas

    International Nuclear Information System (INIS)

    Tomaselli, Sara; Galeano, Federica; Massimi, Luca; Di Rocco, Concezio; Lauriola, Libero; Mastronuzzi, Angela; Locatelli, Franco; Gallo, Angela

    2013-01-01

    High-grade (WHO grade III and IV) astrocytomas are aggressive malignant brain tumors affecting humans with a high risk of recurrence in both children and adults. To date, limited information is available on the genetic and molecular alterations important in the onset and progression of pediatric high-grade astrocytomas and, even less, on the prognostic factors that influence long-term outcome in children with recurrence. A-to-I RNA editing is an essential post-transcriptional mechanism that can alter the nucleotide sequence of several RNAs and is mediated by the ADAR enzymes. ADAR2 editing activity is particularly important in mammalian brain and is impaired in both adult and pediatric high-grade astrocytomas. Moreover, we have recently shown that the recovered ADAR2 activity in high-grade astrocytomas inhibits in vivo tumor growth. The aim of the present study is to investigate whether changes may occur in ADAR2-mediated RNA editing profiles of relapsed high-grade astrocytomas compared to their respective specimens collected at diagnosis, in four pediatric patients. Total RNAs extracted from all tumor samples and controls were tested for RNA editing levels (by direct sequencing on cDNA pools) and for ADAR2 mRNA expression (by qRT-PCR). A significant loss of ADAR2-editing activity was observed in the newly diagnosed and recurrent astrocytomas in comparison to normal brain. Surprisingly, we found a substantial rescue of ADAR2 editing activity in the relapsed tumor of the only patient showing prolonged survival. High-grade astrocytomas display a generalized loss of ADAR2-mediated RNA editing at both diagnosis and relapse. However, a peculiar Case, in complete remission of disease, displayed a total rescue of RNA editing at relapse, intriguingly suggesting ADAR2 activity/expression as a possible marker for long-term survival of patients with high-grade astrocytomas

  2. Non-operative management versus operative management in high-grade blunt hepatic injury.

    Science.gov (United States)

    Cirocchi, Roberto; Trastulli, Stefano; Pressi, Eleonora; Farinella, Eriberto; Avenia, Stefano; Morales Uribe, Carlos Hernando; Botero, Ana Maria; Barrera, Luis M

    2015-08-24

    Surgery used to be the treatment of choice in cases of blunt hepatic injury, but this approach gradually changed over the last two decades as increasing non-operative management (NOM) of splenic injury led to its use for hepatic injury. The improvement in critical care monitoring and computed tomographic scanning, as well as the more frequent use of interventional radiology techniques, has helped to bring about this change to non-operative management. Liver trauma ranges from a small capsular tear, without parenchymal laceration, to massive parenchymal injury with major hepatic vein/retrohepatic vena cava lesions. In 1994, the Organ Injury Scaling Committee of the American Association for the Surgery of Trauma (AAST) revised the Hepatic Injury Scale to have a range from grade I to VI. Minor injuries (grade I or II) are the most frequent liver injuries (80% to 90% of all cases); severe injuries are grade III-V lesions; grade VI lesions are frequently incompatible with survival. In the medical literature, the majority of patients who have undergone NOM have low-grade liver injuries. The safety of NOM in high-grade liver lesions, AAST grade IV and V, remains a subject of debate as a high incidence of liver and collateral extra-abdominal complications are still described. To assess the effects of non-operative management compared to operative management in high-grade (grade III-V) blunt hepatic injury. The search for studies was run on 14 April 2014. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (Ovid), PubMed, ISI WOS (SCI-EXPANDED, SSCI, CPCI-S & CPSI-SSH), clinical trials registries, conference proceedings, and we screened reference lists. All randomised trials that compare non-operative management versus operative management in high-grade blunt hepatic injury. Two authors independently

  3. Complications of nonoperative management of high-grade blunt hepatic injuries.

    Science.gov (United States)

    Kozar, Rosemary A; Moore, John B; Niles, Sarah E; Holcomb, John B; Moore, Ernest E; Cothren, C Clay; Hartwell, Elizabeth; Moore, Frederick A

    2005-11-01

    Nonoperative management of blunt hepatic injuries is highly successful. Complications associated with high-grade injuries, however, have not been well characterized. The purpose of the present study was therefore to define hepatic-related complications and associated treatment modalities in patients undergoing nonoperative management of high-grade blunt hepatic injuries. Three hundred thirty-seven patients from two regional Level I trauma centers with grade 3 to 5 blunt hepatic injuries during a 40-month period were reviewed. Complications and treatment of hepatic-related complications in patients not requiring laparotomy in the first 24 hours were identified. Of 337 patients with a grade 3 to 5 injury, 230 (68%) were managed nonoperatively. There were 37 hepatic-related complications in 25 patients (11%); 63% (5 of 8) of patients with grade 5 injuries developed complications, 21% (19 of 92) of patients with grade 4 injuries, but only 1% (1 of 130) of patients with grade 3 injuries. Complications included bleeding in 13 patients managed by angioembolization (n = 12) and laparotomy (n = 1), liver abscesses in 2 patients managed with computed tomography-guided drainage (n = 2) and subsequent laparotomy (n = 1). In one patient with bleeding, hepatic necrosis followed surgical ligation of the right hepatic artery and required delayed hepatic lobectomy. Sixteen biliary complications were managed with endoscopic retrograde cholangiopancreatography and stenting (n = 7), drainage (n = 5), and laparoscopy (n = 4). Three patients had suspected abdominal sepsis and underwent a negative laparotomy, whereas an additional three patients underwent laparotomy for abdominal compartment syndrome. Nonoperative management of high-grade liver injuries can be safely accomplished. Mortality is low; however, complications in grade 4 and 5 injuries should be anticipated and may require a combination of operative and nonoperative management strategies.

  4. Studies on uranium ore processing

    International Nuclear Information System (INIS)

    Kim, C.H.; Park, S.W.; Lim, J.K.; Chung, M.K.

    1981-01-01

    Chemical and chemical engineering techniques of the uranium ore processing established by France COGEMA (Compagnie Generale des Matieres Nucleaires) have been comprehensively reviewed in preparation for successful test operation of the pilot plant to be completed by the end of 1981. It was found that the amount of sulfuric acid (75 Kg/t, ore) and sodium chlorate (2.5 Kg/t, ore) recommended by COGEMA should be increased up to 100 Kg/t, ore and 10 Kg/t, ore respectively to obtain satisfactory leach of uranium for some ore samples produced at the different pits of Goesan uranium mine. Conditions of the other processes such as solvent extraction, stripping, and precipitation of yellow cake were generally agreed with the results of intensive studies done by this laboratory

  5. Uranium abundance in some sudanese phosphate ores

    International Nuclear Information System (INIS)

    Adam, A.A.; Eltayeb, M.A.H.

    2009-01-01

    This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

  6. Understanding Lateritic Ore Agglomeration Behaviour as a ...

    African Journals Online (AJOL)

    Processing such ores through cost-competitive heap (4-10 m high) leaching as an alternative, requires successful agglomeration of the feed into robust and porous granules. To date, produc-ing of granules with desirable attributes poses a major geotechnical challenge to industry. In the present work, we investigate ...

  7. High-Grade Transformation of Adenoid Cystic Carcinoma Delineated with a Fibrous Rim: A Case Report

    Directory of Open Access Journals (Sweden)

    Hamide Sayar

    2013-09-01

    Full Text Available Background: High-grade transformation or dedifferentiation in carcinoma is progression of a low-grade malignant neoplasm to a high-grade carcinoma or poorly differentiated adenocarcinoma. This is rarely observed in adenoid cystic carcinoma of the salivary glands. Case Report: A 39 year-old woman presented with a painless mass at the left submandibulary region that had been growing slowly for 5 years. Submandibulary mass resection revealed a mass with peripheral adenoid cystic carcinoma and a central high-grade tumor delineated with a fibrous rim, raising the possibility of a hybrid or composite carcinoma, requiring differential diagnosis depending upon morphology and immunohistochemistry findings. The final histopathological diagnosis was high-grade transformation of adenoid cystic carcinoma. After surgical therapy, the patient was irradiated to the neck and submandibulary region. No sign of tumor recurrence has been evident for 36 months. Conclusion: This present case seems to be another rare case with high-grade transformation of adenoid cystic carcinoma and the fibrous rim may be a histopathological feature of such cases, which should be kept in mind.

  8. Siltation of Ore Particles in Leaching Tanks: Causative Factors and ...

    African Journals Online (AJOL)

    Michael

    2016-12-02

    Dec 2, 2016 ... In this era of low grade ores and low metal price regimes, most plants now ... factors for siltation of tanks in the Carbon-in-Leach. Plant of Gold Fields Ghana Ltd at ..... interests are in rare earth elements minerals beneficiation ...

  9. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  10. China's emergence as the world's leading iron-ore-consuming country

    Science.gov (United States)

    Kirk, W.S.

    2004-01-01

    China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

  11. Determination of soil, sand and ore primordial radionuclide concentrations by full-spectrum analyses of high-purity germanium detector spectra

    International Nuclear Information System (INIS)

    Newman, R.T.; Lindsay, R.; Maphoto, K.P.; Mlwilo, N.A.; Mohanty, A.K.; Roux, D.G.; Meijer, R.J. de; Hlatshwayo, I.N.

    2008-01-01

    The full-spectrum analysis (FSA) method was used to determine primordial activity concentrations (ACs) in soil, sand and ore samples, in conjunction with a HPGe detector. FSA involves the least-squares fitting of sample spectra by linear combinations of 238 U, 232 Th and 40 K standard spectra. The differences between the FSA results and those from traditional windows analyses (using regions-of-interest around selected photopeaks) are less than 10% for all samples except zircon ore, where FSA yielded an unphysical 40 K AC

  12. Upgrading of boron ores and colemanite flotation

    International Nuclear Information System (INIS)

    Yarar, B.; Mager, J.

    1979-01-01

    Processes applied for the processing and upgrading of sodium and calcium borates in Turkey are described. Details of froth flotation study where a low grade colemanite ore containing calcite and clays as a gangue minerals are given. It has been found that, at the natural pH of a colemanite-containing pulp (pH=9,2) it is possible to float colemanite selectively using dodecyl benzene sulphonate or its combinations with a non-polar reagent or naphthenic acids. (author)

  13. Zeolitization at uranium ore manifestation

    International Nuclear Information System (INIS)

    Petrosyan, R.V.; Buntikova, A.F.

    1981-01-01

    The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

  14. Gastric low-grade MALT lymphoma, high-grade MALT lymphoma and diffuse large B cell lymphoma show different frequencies of trisomy

    NARCIS (Netherlands)

    Hoeve, M A; Gisbertz, I A; Schouten, H C; Schuuring, E; Bot, F J; Hermans, J; Hopman, A; Kluin, P M; Arends, J E; van Krieken, J H

    1999-01-01

    Gastric MALT lymphoma is a distinct entity related to Helicobacter pylori gastritis. Some studies suggest a role for trisomy 3 in the genesis of these lymphomas, but they mainly focused on low-grade MALT lymphoma. Gastric MALT lymphoma, however, comprises a spectrum from low- to high-grade cases.

  15. Altered intraoperative cerebrovascular reactivity in brain areas of high-grade glioma recurrence.

    Science.gov (United States)

    Fierstra, Jorn; van Niftrik, Bas; Piccirelli, Marco; Burkhardt, Jan Karl; Pangalu, Athina; Kocian, Roman; Valavanis, Antonios; Weller, Michael; Regli, Luca; Bozinov, Oliver

    2016-07-01

    Current MRI sequences are limited in identifying brain areas at risk for high grade glioma recurrence. We employed intraoperative 3-Tesla functional MRI to assess cerebrovascular reactivity (CVR) after high-grade glioma resection and analyzed regional CVR responses in areas of tumor recurrence on clinical follow-up imaging. Five subjects with high-grade glioma that underwent an intraoperative Blood Oxygen-Level Dependent (BOLD) MRI CVR examination and had a clinical follow-up of at least 18months were selected from a prospective database. For this study, location of tumor recurrence was spatially matched to the intraoperative imaging to assess CVR response in that particular area. CVR is defined as the percent BOLD signal change during repeated cycles of apnea. Of the 5 subjects (mean age 44, 2 females), 4 were diagnosed with a WHO grade III and 1 subject with a WHO grade IV glioma. Three subjects exhibited a tumor recurrence on clinical follow-up MRI (mean: 15months). BOLD CVR measured in the spatially matched area of tumor recurrence was on average 94% increased (range-32% to 183%) as compared to contralateral hemisphere CVR response, 1.50±0.81 versus 1.03±0.46 respectively (p=0.31). For this first analysis in a small cohort, we found altered intraoperative CVR in brain areas exhibiting high grade glioma recurrence on clinical follow-up imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Uranium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.) [es

  17. Niobium ore OKA-1

    International Nuclear Information System (INIS)

    Steger, H.F.; Bowman, W.S.

    1981-01-01

    A 287-kg sample of a niobium ore, OKA-1, from Oka, Quebec, was prepared as a compositional reference material. OKA-1 was ground to minus 74 μm, blended in one lot, tested for homogeneity by X-ray fluorescence and chemical methods and bottled in 200-g units. In a 'free-choice' round-robin analytical program, 22 laboratories contributed results for niobium in each of two bottles of OKA-1. A statistical analysis of the data gave a recommended value of 0.37 +- 0.01% for niobium

  18. PREVALENCE OF HUMAN PAPILLOMAVIRUS GENOTYPES IN LOW AND HIGH GRADE SQUAMOUS INTRAEPITHELIAL LESIONS AT CERVICAL TISSUE

    OpenAIRE

    Prasetyo, Rizki Eko; Mastutik, Gondo; Mustokoweni, Sjahjenny

    2017-01-01

    HPV infection is known to cause cervical cancer. This study aimed to identify the variant of HPV genotypes of cervical precancerous lesions from low grade squamous intraepithelial lesion  (LSIL) and high grade squamous intraepithelial lesion (HSIL). This was an explorative study using formalin fix paraffin embedded (FFPE) from cervical precancerous lesions at Dr. Soetomo Hospital, Surabaya. DNA was extracted from FFPE and hybridized for HPV genotyping using Ampliquality HPV Type Express kit (...

  19. Energy Concept Understanding of High School Students: A Cross-Grade Study

    Science.gov (United States)

    Takaoglu, Zeynep Baskan

    2018-01-01

    Energy is a difficult concept to be understood by students of all levels. Thus, the aim of the study is to determine how high school students at different levels perceive the energy and related concepts. In line with this purpose, 173 students in total of which 57 ones of the 9th grade, 94 ones of the 10th grade and 22 ones of the 11th grade…

  20. High-Grade Hydronephrosis Predicts Poor Outcomes After Radical Cystectomy in Patients with Bladder Cancer

    OpenAIRE

    Kim, Dong Suk; Cho, Kang Su; Lee, Young Hoon; Cho, Nam Hoon; Oh, Young Taek; Hong, Sung Joon

    2010-01-01

    We examined whether the presence and severity of preoperative hydronephrosis have prognostic significance in patients who underwent radical cystectomy for transitional cell carcinoma of the bladder. The medical records of 457 patients who underwent radical cystectomy for bladder cancer between 1986 and 2005 were retrospectively reviewed. Following the Society for Fetal Urology grading system, patients were divided into low-, and high-grade hydronephrosis groups. Clinicopathologic factors asso...

  1. Functional activity of microorganisms in mining and processing of copper-nickel ores in the Murmansk Region

    Directory of Open Access Journals (Sweden)

    Fokina N. V.

    2018-03-01

    Full Text Available The quantitative indices and structure of the microbial community in flotation samples of sulfide copper-nickel ores at concentration plant of Kola Mining and Metallurgical Company have been determined. The smallest number of saprotrophic and oligotrophic bacteria has been observed in samples of ore and recycled water, which can be explained by the low temperature of samples and the lack of nutrients. It has been found out that the bacteria contained in the ore and recycling water flowing from the tailings increased their number during the flotation process due to coming of the organic compounds with the flotation reagents, aeration and increased temperature. Dominating strains have been isolated from recycled water and basic flotation products and classified as Pseudomonas. It has been shown that with an increase in the number of bacteria, the flotation time of copper-nickel ores increases. There is also a tendency to change the extraction of copper and nickel, which can be caused by both the increase in the flotation time for operations and the change in the number of bacteria in the circulating water. The thionic bacteria have been distinguished from the flow tailings of the Allarechensk deposit. The heap leaching experiments have proved the bacterial leaching to give good results on the ore samples passed through magnetic separation, having shown high content of the nickel and copper in filters. When leaching low-grade ore of the Nude Terrasa, the advantage of bacterial leaching use in comparison with the sulphuric-acid leaching only to copper has been revealed. The nickel content in the filtrates for bacterial leaching is 275 mg/l, and for sulfuric acid – 310 mg/l. The average copper content in the filtrates is 19 and 15 mg/l.

  2. [Diagnostic imaging of high-grade astrocytoma: heterogeneity of clinical manifestation, image characteristics, and histopathological findings].

    Science.gov (United States)

    Okajima, Kaoru; Ohta, Yoshio

    2012-10-01

    Recent developments in diagnostic radiology, which have enabled accurate differential diagnoses of brain tumors, have been well described in the last three decades. MR and PET imaging can also provide information to predict histological grades and prognoses that might influence treatment strategies. However, high-grade astrocytomas consist of many different subtypes that are associated with different imaging and histological characteristics. Hemorrhage and necrosis results in a variety of imaging features, and infiltrative tumor growth entrapping normal neurons may cause different clinical manifestations. We reviewed patients with high-grade astrocytomas that showed various imaging characteristics, with special emphasis on initial symptoms and histological features. Clinicopathological characteristics of astrocytomas were also compared with other malignant tumors. Neurological deficits were not notable in patients with grade 3-4 astrocytomas when they showed infiltrative tumor growth, while brain metastases with compact cellular proliferation caused more neurological symptoms. Infiltrative tumors did not show any enhancing masses on MR imaging, but these tumors may show intratumor heterogeneity. Seizures were reported to be more frequent in low-grade glioma and in secondary glioblastoma. Tumor heterogeneity was also reported in molecular genetic profile, and investigators identified some subsets of astrocytomas. They investigated IHD1/2 mutation, EGFR amplification, TP53 mutation, Ki-67 index, etc. In summary, high-grade astrocytomas are not homogenous groups of tumors, and this is associated with the heterogeneity of clinical manifestation, image characteristics, and histopathological findings. Molecular studies may explain the tumor heterogeneity in the near future.

  3. Large palpable ductal carcinoma in situ is Her-2 positive with high nuclear grade.

    Science.gov (United States)

    Monabati, Ahmad; Sokouti, Ali-Reza; Noori, Sadat Noori; Safaei, Akbar; Talei, Abd-Rasul; Omidvari, Shapoor; Azarpira, Negar

    2015-01-01

    Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group with variable clinical presentation. The exact molecular mechanism is not known why some ductal carcinomas may reach to such a large size but still remains in situ. Although, molecular classification of DCIS lesions and nuclear grading are important for identification of more aggressive lesions but it is not sufficient. Our aim was to examine the expression pattern of immunohistochemical (IHC) markers of ER, PR, HER-2 in palpable DCIS lesions and compare with clinicopathological findings. Our center is referral hospital from South of Iran. Samples were obtained from fifty four patients with a diagnosis of palpable DCIS. Equivocal (2+) case in HER-2 IHC testing was more characterized by chromogenic in situ hybridization. The positive frequency of HER2, ER, and PR was 92%, 48%, and 37% respectively. Palpable DCIS lesions were significantly more HER-2 positive (92%). The DCIS cases were more likely to be of high nuclear grade (grade III) and Her-2 positive cases were more likely to be of high nuclear grade than intermediate grade. All ER negative tumors had high nuclear grade. The Her-2 positivity is suggested as the most important factor responsible for marked in situ proliferation and production of palpable mass.

  4. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Directory of Open Access Journals (Sweden)

    Peter J. Williams

    2010-04-01

    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  5. A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

    Directory of Open Access Journals (Sweden)

    Mendes F.D.

    2003-01-01

    Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

  6. Extraction of metals from ores by bacterial leaching: present status and future prospects

    International Nuclear Information System (INIS)

    Kelly, D.P.

    1977-01-01

    The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

  7. Effect of desliming on the flotation of a complax copper ore from China

    OpenAIRE

    Chen Yong; Song Yong Sheng; Li Wen Juan; Zhou Gui Ying

    2016-01-01

    The complex copper oxide ore sample was taken from Deerni copper deposit, Qinghai Province of China. Batch flotation tests had been conducted to upgrade the copper concentrate by conventional amyl xanthate reagents under 73% -74 μm of the particle size; however, the unsatisfied results (Cu grade of 18.21% and recovery of 59.25%) were obtained. Also there are a large amount of slimes trapped in the concentrate and high-dosages consumption of reagents, for example, more than 2.5 kg/t sodium sul...

  8. Comparison of Utility of Histogram Apparent Diffusion Coefficient and R2* for Differentiation of Low-Grade From High-Grade Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Zhang, Yu-Dong; Wu, Chen-Jiang; Wang, Qing; Zhang, Jing; Wang, Xiao-Ning; Liu, Xi-Sheng; Shi, Hai-Bin

    2015-08-01

    The purpose of this study was to compare histogram analysis of apparent diffusion coefficient (ADC) and R2* for differentiating low-grade from high-grade clear cell renal cell carcinoma (RCC). Forty-six patients with pathologically confirmed clear cell RCC underwent preoperative BOLD and DWI MRI of the kidneys. ADCs based on the entire tumor volume were calculated with b value combinations of 0 and 800 s/mm(2). ROI-based R2* was calculated with eight TE combinations of 6.7-22.8 milliseconds. Histogram analysis of tumor ADCs and R2* values was performed to obtain mean; median; width; and fifth, 10th, 90th, and 95th percentiles and histogram inhomogeneity, kurtosis, and skewness for all lesions. Thirty-three low-grade and 13 high-grade clear cell RCCs were found at pathologic examination. The TNM classification and tumor volume of clear cell RCC significantly correlated with histogram ADC and R2* (ρ = -0.317 to 0.506; p histogram ADC and R2* indexes, 10th percentile ADC had the highest accuracy (91.3%) in discriminating low- from high-grade clear cell RCC. R2* in discriminating hemorrhage was achieved with a threshold of 68.95 Hz. At this threshold, high-grade clear cell RCC had a significantly higher prevalence of intratumor hemorrhage (high-grade, 76.9%; low-grade, 45.4%; p Histogram analysis of ADC and R2* allows differentiation of low- from high-grade clear cell RCC with high accuracy.

  9. Fundamentals of fast reduction of ultrafine iron ore at low temperature

    Institute of Scientific and Technical Information of China (English)

    Pei Zhao; Peimin Guo

    2008-01-01

    Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

  10. Field experimental observations of highly graded sediment plumes.

    Science.gov (United States)

    Jensen, Jacob Hjelmager; Saremi, Sina; Jimenez, Carlos; Hadjioannou, Louis

    2015-06-15

    A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes, gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in the water column, and facing the plume at different angles. The processes were captured using GoPro-Hero-series cameras. The high-quality underwater footage from near-surface, mid-depth and near-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Soil mercury distribution in adjacent coniferous and deciduous stands highly impacted by acid rain in the Ore Mountains, Czech Republic

    Science.gov (United States)

    Navrátil, Tomáš; Shanley, James B.; Rohovec, Jan; Oulehle, Filip; Šimeček, Martin; Houška, Jakub; Cudlín, Pavel

    2016-01-01

    Forests play a primary role in the cycling and storage of mercury (Hg) in terrestrial ecosystems. This study aimed to assess differences in Hg cycling and storage resulting from different vegetation at two adjacent forest stands - beech and spruce. The study site Načetín in the Czech Republic's Black Triangle received high atmospheric loadings of Hg from coal combustion in the second half of the 20th century as documented by peat accumulation rates reaching 100 μg m−2 y−1. In 2004, the annual litterfall Hg flux was 22.5 μg m−2 y−1 in the beech stand and 14.5 μg m−2 y−1 in the spruce stand. Soil concentrations and pools of Hg had a strong positive relation to soil organic matter and concentrations of soil sulfur (S) and nitrogen (N). O-horizon Hg concentrations ranged from 245 to 495 μg kg−1 and were greater in the spruce stand soil, probably as a result of greater dry Hg deposition. Mineral soil Hg concentrations ranged from 51 to 163 μg kg−1 and were greater in the beech stand soil due to its greater capacity to store organic carbon (C). The Hg/C ratio increased with depth from 0.3 in the O-horizon to 3.8 μg g−1 in the C horizon of spruce soil and from 0.7 to 2.7 μg g−1 in beech soil. The Hg/C ratio was greater at all mineral soil depths in the spruce stand. The organic soil Hg pools in beech and spruce stands (6.4 and 5.7 mg m−2, respectively) were considerably lower than corresponding mineral soil Hg pools (39.1 and 25.8 mg m−2). Despite the important role of S in Hg cycling, differences in soil Hg distribution at both stands could not be attributed to differences in soil sulfur speciation.

  12. [Experience of diagnosis and treatment of exogenous high-grade fever].

    Science.gov (United States)

    Xiong, Xing-jiang; Wang, Jie

    2011-06-01

    There is a regular pattern in the diagnosis and treatment of exogenous high-grade fever, of which the key point is formula syndrome identification. Syndrome differentiation of the six channels is appropriate for not only exogenous cold but also various other conditions. The diagnosis and treatment of high-grade fever can also follow the law of syndrome differentiation of the six channels. The theory of epidemic febrile diseases stems from and elaborates on an understanding of exogenous febrile conditions, so many effective formulas used to treat epidemic febrile diseases also have great value in the treatment of high-grade fever. Deteriorated syndrome, which is central to this condition, is very commonly seen in cases of high-grade fever, the key therapeutic principle of which is established according to syndromes. Allowing analysis that does not rigidly adhere to either established modern diagnosis or traditional Chinese syndromes, prominent achievements could be made in treating high-grade fever by summarizing the regular presenting patterns in terms of the constitution and symptoms.

  13. The treatment of uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1979-01-01

    After having described the main steps in the treatment of uranium ores, the author describes the treament activities for these ores, as they are organized in France and in the African countries having made cooperation agreements with France in this field [fr

  14. Research and development of intelligent controller for high-grade sanitary ware

    Science.gov (United States)

    Bao, Kongjun; Shen, Qingping

    2013-03-01

    With the social and economic development and people's living standards improve, more and more emphasis on modern society, people improve the quality of family life, the use of intelligent controller applications in high-grade sanitary ware physiotherapy students. Analysis of high-grade sanitary ware physiotherapy common functions pointed out in the production and use of the possible risks, proposed implementation of the system hardware and matching, given the system software implementation process. High-grade sanitary ware physiotherapy intelligent controller not only to achieve elegant and beautiful, simple, physical therapy, water power, deodorant, multi-function, intelligent control, to meet the consumers, the high-end sanitary ware market, strong demand, Accelerate the enterprise product Upgrade and improve the competitiveness of enterprises.

  15. Ambient Temperature Flotation of Sedimentary Phosphate Ore Using Cottonseed Oil as a Collector

    Directory of Open Access Journals (Sweden)

    Yaoyang Ruan

    2017-04-01

    Full Text Available The mid-low grade sedimentary phosphate ore, abundant in silicate and carbonate gangue minerals, exhibits a poor processability. It is conventionally enriched using high temperature flotation to remove silicate gangues with fatty acid as a collector. Cottonseed oil has been proved to be an efficient collector for achieving ambient temperature flotation of the sedimentary phosphate ore used in this study. Flotation kinetics was investigated to ascertain the excellent collecting performance of cottonseed oil, as compared with oleic acid, and the phosphate flotation fitted well with the first-order flotation model. Based on the analysis of flotation reagent effect on the direct flotation process using the response surface methodology (RSM, a closed circuit of direct-reverse flotation for stepwise removing silicate and carbonate gangues from the sedimentary phosphate ore was established. Consequently, a required high quality of phosphate concentrate containing 30.16% P2O5 was obtained, with a recovery of 90.90%. Scanning electron microscopy (SEM and X-ray diffraction analysis (XRD of the flotation products confirmed that the majority of silicate and carbonate gangues were effectively removed from the concentrate products.

  16. Field experimental observations of highly graded sediment plumes

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina; Jimenez, Carlos

    2015-01-01

    A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes......-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages...... are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model....

  17. Summary of the mineralogy of the Colorado Plateau uranium ores

    Science.gov (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

    1956-01-01

    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  18. Utilisation of iron ore tailings as aggregates in concrete

    OpenAIRE

    Francis Atta Kuranchie; Sanjay Kumar Shukla; Daryoush Habibi; Alireza Mohyeddin

    2015-01-01

    Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength we...

  19. Study of the dry processing of uranium ores

    International Nuclear Information System (INIS)

    Guillet, H.

    1959-02-01

    A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [fr

  20. Concomitant injuries are an important determinant of outcome of high-grade blunt hepatic trauma.

    Science.gov (United States)

    Schnüriger, B; Inderbitzin, D; Schafer, M; Kickuth, R; Exadaktylos, A; Candinas, D

    2009-01-01

    Little is known about the clinical importance of concomitant injuries in polytraumatized patients with high-grade blunt liver injury. A retrospective single-centre study was performed to investigate the safety of non-operative management of liver injury and the impact of concomitant intra- and extra-abdominal injuries on clinical outcome. Some 183 patients with blunt liver injury were admitted to Berne University Hospital, Switzerland, between January 2000 and December 2006. Grade 3-5 injuries were considered to be high grade. Immediate laparotomy was required by 35 patients (19.1 per cent), owing to extrahepatic intra-abdominal injury (splenic and vascular injuries, perforations) in 21 cases. The mortality rate was 16.9 per cent; 22 of the 31 deaths were due to concomitant lesions. Of 81 patients with high-grade liver injury, 63 (78 per cent) were managed without surgery; liver-related and extra-abdominal complication rates in these patients were 11 and 17 per cent respectively. Grades 4 and 5 liver injury were associated with hepatic-related and extra-abdominal complications. Concomitant injuries are a major determinant of outcome in patients with blunt hepatic injury and should be given high priority by trauma surgeons. An algorithm for the management of blunt liver injury is proposed. Copyright (c) 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  1. Leadership Strategies in Implementation of High-School Standards-Based Grading Systems

    Science.gov (United States)

    Pritzl, Jerome

    2016-01-01

    This multi-site case study examined leadership strategies used during successful implementation of standards-based grading systems in three Wisconsin high schools. It found that leaders' reported commitment, patience, and persistence showed evidence of sustainable, high-functioning systems. It drew two main conclusions: first, school leaders need…

  2. The End-of-Life Phase of High-Grade Glioma Patients: Dying With Dignity?

    NARCIS (Netherlands)

    Sizoo, E.M.; Taphoorn, M.J.B.; Uitdehaag, B.M.J.; Heimans, J.J.; Deliens, L.; Reijneveld, J.C.; Pasman, H.R.W.

    2013-01-01

    Background. In the end-of-life (EOL) phase, high-grade glioma (HGG) patients have a high symptom burden and often lose independence because of physical and cognitive dysfunction. This might affect the patient's personal dignity. We aimed to (a) assess the proportion of HGG patients dying with

  3. Disentangling the Predictive Validity of High School Grades for Academic Success in University

    Science.gov (United States)

    Vulperhorst, Jonne; Lutz, Christel; de Kleijn, Renske; van Tartwijk, Jan

    2018-01-01

    To refine selective admission models, we investigate which measure of prior achievement has the best predictive validity for academic success in university. We compare the predictive validity of three core high school subjects to the predictive validity of high school grade point average (GPA) for academic achievement in a liberal arts university…

  4. The end-of-life phase of high-grade glioma patients: dying with dignity?

    NARCIS (Netherlands)

    Sizoo, Eefje M.; Taphoorn, Martin J. B.; Uitdehaag, Bernard; Heimans, Jan J.; Deliens, Luc; Reijneveld, Jaap C.; Pasman, H. Roeline W.

    2013-01-01

    In the end-of-life (EOL) phase, high-grade glioma (HGG) patients have a high symptom burden and often lose independence because of physical and cognitive dysfunction. This might affect the patient's personal dignity. We aimed to (a) assess the proportion of HGG patients dying with dignity as

  5. Association of invasive breast carcinoma and multicentric high grade astrocytoma: a case report with a review.

    Science.gov (United States)

    Pour, P Hossein; Forouzandeh, M; Beni, A Naderi; Beni, Z Naderi; Hoseinpour, P

    2011-03-01

    Breast cancer is the most common cancer in women. Multicentric gliomas are uncommon lesions of the central nervous system (CNS) with an unprecise rate of occurrence that diffusely infiltrate large portions of the brain. High grade astrocytoma is the most agressive form of gliomas and often has a distinct neuroimaging pattern with a poor prognosis. We report a case of a 29-year-old woman patient with primary breast carcinoma and high grade astrocytoma subsequently developed. The woman was treated by mastectomy and 20 months post-diagnosis of the cancer she exhibited a transient facial paralysis. Magnetic resonance imaging (MRI) revealed two cranial masses suspicious of metastasis. A complete tumor removal from the brain was performed. On histological examination, this tumor was a high grade astrocytoma.

  6. Prostatectomy-based validation of combined urine and plasma test for predicting high grade prostate cancer.

    Science.gov (United States)

    Albitar, Maher; Ma, Wanlong; Lund, Lars; Shahbaba, Babak; Uchio, Edward; Feddersen, Søren; Moylan, Donald; Wojno, Kirk; Shore, Neal

    2018-03-01

    Distinguishing between low- and high-grade prostate cancers (PCa) is important, but biopsy may underestimate the actual grade of cancer. We have previously shown that urine/plasma-based prostate-specific biomarkers can predict high grade PCa. Our objective was to determine the accuracy of a test using cell-free RNA levels of biomarkers in predicting prostatectomy results. This multicenter community-based prospective study was conducted using urine/blood samples collected from 306 patients. All recruited patients were treatment-naïve, without metastases, and had been biopsied, designated a Gleason Score (GS) based on biopsy, and assigned to prostatectomy prior to participation in the study. The primary outcome measure was the urine/plasma test accuracy in predicting high grade PCa on prostatectomy compared with biopsy findings. Sensitivity and specificity were calculated using standard formulas, while comparisons between groups were performed using the Wilcoxon Rank Sum, Kruskal-Wallis, Chi-Square, and Fisher's exact test. GS as assigned by standard 10-12 core biopsies was 3 + 3 in 90 (29.4%), 3 + 4 in 122 (39.8%), 4 + 3 in 50 (16.3%), and > 4 + 3 in 44 (14.4%) patients. The urine/plasma assay confirmed a previous validation and was highly accurate in predicting the presence of high-grade PCa (Gleason ≥3 + 4) with sensitivity between 88% and 95% as verified by prostatectomy findings. GS was upgraded after prostatectomy in 27% of patients and downgraded in 12% of patients. This plasma/urine biomarker test accurately predicts high grade cancer as determined by prostatectomy with a sensitivity at 92-97%, while the sensitivity of core biopsies was 78%. © 2018 Wiley Periodicals, Inc.

  7. Geological-economic analysis on the exploration of backup resources for depleted mines in Lujing uranium ore-field, central-southern China

    International Nuclear Information System (INIS)

    Li Deping; Wang Zhicheng; Fan Shaoyun

    2006-01-01

    With the geological-economic evaluation program for pithead heap-leaching mining uranium deposits developed by the authors and the data of column-leaching tests and the geological reserve, the geological-economic evaluation is made to the residual geological reserves of both Lujing and Huangfengling deposit, and the geological reserves of Yangjiaonao deposit of the depleted mines in Lujing uranium ore-field, central-southern China. The results of static analysis on these reserves show that the residual geological reserves of both Lujing and Huangfengling deposit belong to sub-profitable type, but the ones of Yangjiaonao deposit is profitable with 26.56% tax-before profit. 1 tU profitable type of ore from Yangjiaonao deposit can use 2.40-3.79 tU subprofitable type of ores from Lujing and Huangfengling deposit. In order to solving the problem on scarcity of backup resources of the depleted mines in Lujing uranium ore-field and using the existing sub-profitable type of geological reserves, it is suggested that the high grade of profitable type of deposits should be explored around the exhausting mines so that the production of the mines could be profitable by the pithead heap-leaching mining method with arrangement groups of both sub-profitable and profitable type of ores. (authors)

  8. Uranium ore processing

    International Nuclear Information System (INIS)

    Ritcey, G.M.; Haque, K.E.; Lucas, B.H.; Skeaff, J.M.

    1983-01-01

    The authors have developed a complete method of recovering separately uranium, thorium and radium from impure solids such as ores, concentrates, calcines or tailings containing these metals. The technique involves leaching, in at least one stage. The impure solids in finely divided form with an aqueous leachant containing HCl and/or Cl 2 until acceptable amounts of uranium, thorium and radium are dissolved. Uranium is recovered from the solution by solvent extraction and precipitation. Thorium may also be recovered in the same manner. Radium may be recovered by at least one ion exchange, absorption and precipitation. This amount of iron in the solution must be controlled before the acid solution may be recycled for the leaching process. The calcine leached in the first step is prepared in a two stage roast in the presence of both Cl 2 and a metal sulfide. The first stage is at 350-450 0 and the second at 550-700 0

  9. Preventing the embrittling by hydrogen when galvanizing high-grade steel

    Energy Technology Data Exchange (ETDEWEB)

    Paatsch, W.

    1987-09-01

    Galvanic precipitation of a double layer consisting of a dull nickel layer overlaid with a brilliant zinc layer on low-alloyed high-strength steel grades leads to the forming of zinc-nickel alloy layers during the subsequent heat treatment. According to traction tests carried out on high-strength steel grades, as well as to hydrogen permeability tests, this process prevents embrittling by hydrogen which might be caused by galvanic process sequences - and creates a diffusion block at the same time. The alloy layers have an excellent corrosion resistance and temperature stability.

  10. Patient Outcomes in the Operative and Nonoperative Management of High-Grade Spondylolisthesis in Children

    DEFF Research Database (Denmark)

    Lundine, K. M.; Lewis, S. J.; Al-Aubaidi, Zaid

    2014-01-01

    Background:The optimal management of high-grade spondylolisthesis in the growing child is controversial. Some authors have advocated for surgery in all cases regardless of symptoms. Surgical intervention results in a >10% risk of complications with increased risk of neurological injury associated...... with slip reduction maneuvers. There is a paucity of literature regarding nonoperative management in this setting. This study sought to obtain outcome measures in pediatric patients with high-grade spondylolisthesis managed either operatively or nonoperatively.Methods:Database review was performed...

  11. Hydrogen Plasma Processing of Iron Ore

    Science.gov (United States)

    Sabat, Kali Charan; Murphy, Anthony B.

    2017-06-01

    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  12. Yield of Cytology Surveillance After High-Grade Vulvar Intraepithelial Neoplasia or Cancer.

    Science.gov (United States)

    Kuroki, Lindsay M; Frolova, Antonina I; Wu, Ningying; Liu, Jingxia; Powell, Matthew; Thaker, Premal H; Massad, L Stewart

    2017-07-01

    The aim of the study was to estimate the risk of high-grade cervical and vaginal intraepithelial neoplasia (CIN/VAIN 2+) and cancer among women treated surgically for high-grade vulvar intraepithelial neoplasia (HGVIN) and vulvar cancer. We performed a retrospective cohort study of women who underwent surgery for HGVIN/vulvar cancer between 2006 and 2010. Univariate and multivariate analyses using stepwise selection were used to identify correlates of abnormal cytology after treatment for VIN and vulvar cancer. Among 191 women under surveillance for a median of 3.7 years who underwent treatment for HGVIN/vulvar cancer, primary vulvar lesions included VIN 2 (10, 5%), VIN 3 (102, 53%), and carcinoma (79, 41%). During follow-up, 71 (37%) had abnormal cytology, including 47 (25%) low grade, 23 (12%) high grade, and 1 (0.5%) carcinoma. Subsequent risk for VAIN 2+ was 11% (6/57) after previous hysterectomy and 8% for CIN 2+ (10/124) with intact cervix. Overall risk for CIN 3+ was 5%. Correlates of high-grade cytology after treatment for HGVIN/vulvar cancer included nonwhite race (odds ratio [OR] = 3.3, 95% CI = 1.50-7.36), immunodeficiency (OR = 4.2, 95% CI = 1.76-9.94), and previous abnormal cytology (OR = 2.7, 95% CI = 1.29-5.78). Stepwise multivariate analysis revealed immunosuppression as the only significant correlate of high-grade cytology after vulvar treatment (adjusted OR = 3.7, 95% CI = 1.26-10.83). Women with HGVIN/cancer should have cervical/vaginal cytology before vulvar surgery. Those with a negative cervical or vaginal cytology result should undergo cytology testing at 1- to 3-year intervals, based on the threshold for CIN 3+ set forth by the American Society for Colposcopy and Cervical Pathology.

  13. Obtention of high purity silica from the flotation waste of itabiritic ore; Obtencao de silica de elevada pureza a partir do rejeito de flotacao de um minerio itabiritico

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Polyana Fabricia Fernandes

    2016-10-01

    Banded iron formations are exploited as iron mineral in 'Quadrilatero Ferrifero' of Minas Gerais (MG) State, Brazil. About half of the amount of extracted material becomes tailings, which are stored in tailing dams or used for filling mining pits. Tens of thousands of tons are generated daily in operating mines in this region, causing concern about the environmental liabilities, and costs to manage the tailing dams. Miners are committed to finding uses for these wastes in other productive chains. This thesis aimed to obtain high purity silica from the flotation tailings of banded iron formations using classical techniques for ore processing, such as particle size classification and magnetic separation, followed by hydrometallurgical leaching, also alkaline fusion and chemical precipitation. The tailings samples was collected in the tailings dam of Peak Mine operated by Vale A.S., in Itabirito – MG. This sample had initially 33.4% by weight SiO{sub 2}, 57.4% wt Fe{sub 2}O{sub 3} and 8.31% wt Al{sub 2}O{sub 3}. After desliming for disposal of the fine particles (-37μm) the composition was 68.0% SiO{sub 2}, 31.4% Fe{sub 2}O{sub 3} and 0.50% Al{sub 2}O{sub 3}. After magnetic separation, the composition was 93.8% SiO{sub 2}, 1.16% Fe{sub 2}O{sub 3} and 3.80% Al{sub 2}O{sub 3}. After acid leaching l or digestion to remove impurities, it was possible to obtain silica with 98% purity. The fusion with sodium hydroxide, followed by alkaline leaching of sodium silicate and silica precipitation gave purities of about 99.5%. Values even higher may be possible with optimization of the parameters of alkaline fusion or by repeating the process from the product with purity of 99.5%. The iron oxide content and the aluminum main contaminants were 0.01% and 0.07%, respectively. Amorphous silica was obtained with high specific surface (322 m{sup 2}/g) and particle size less than 200 nm. Depending on the application, a control should be made for the impurities, such as

  14. Risk score predicts high-grade prostate cancer in DNA-methylation positive, histopathologically negative biopsies.

    Science.gov (United States)

    Van Neste, Leander; Partin, Alan W; Stewart, Grant D; Epstein, Jonathan I; Harrison, David J; Van Criekinge, Wim

    2016-09-01

    Prostate cancer (PCa) diagnosis is challenging because efforts for effective, timely treatment of men with significant cancer typically result in over-diagnosis and repeat biopsies. The presence or absence of epigenetic aberrations, more specifically DNA-methylation of GSTP1, RASSF1, and APC in histopathologically negative prostate core biopsies has resulted in an increased negative predictive value (NPV) of ∼90% and thus could lead to a reduction of unnecessary repeat biopsies. Here, it is investigated whether, in methylation-positive men, DNA-methylation intensities could help to identify those men harboring high-grade (Gleason score ≥7) PCa, resulting in an improved positive predictive value. Two cohorts, consisting of men with histopathologically negative index biopsies, followed by a positive or negative repeat biopsy, were combined. EpiScore, a methylation intensity algorithm was developed in methylation-positive men, using area under the curve of the receiver operating characteristic as metric for performance. Next, a risk score was developed combining EpiScore with traditional clinical risk factors to further improve the identification of high-grade (Gleason Score ≥7) cancer. Compared to other risk factors, detection of DNA-methylation in histopathologically negative biopsies was the most significant and important predictor of high-grade cancer, resulting in a NPV of 96%. In methylation-positive men, EpiScore was significantly higher for those with high-grade cancer detected upon repeat biopsy, compared to those with either no or low-grade cancer. The risk score resulted in further improvement of patient risk stratification and was a significantly better predictor compared to currently used metrics as PSA and the prostate cancer prevention trial (PCPT) risk calculator (RC). A decision curve analysis indicated strong clinical utility for the risk score as decision-making tool for repeat biopsy. Low DNA-methylation levels in PCa-negative biopsies led

  15. Studies on uranium ore processing

    International Nuclear Information System (INIS)

    Suh, I.S.; Chun, J.K.; Park, S.W.; Choi, S.J.; Lee, C.H.; Chung, M.K.; Lim, J.K.

    1983-01-01

    For the exploitation of domestic uranium ore deposit, comprehensive studies on uranium ore processing of the Geum-San pit ore are carried out. Physical and chemical characteristics of the Geum-San ore are similar to those of Goe-San ore and the physical beneficiation could not be applicable. Optimum operating conditions such as uranium leaching, solid-liquid separation, solvent extraction and precipitation of yellow cake are found out and the results are confirmed by the continous operation of the micro-plant with the capacity of 50Kg, ore/day. In order to improve the process of ore milling pilot plant installed recently, the feasibility of raffinate-recycle and the precipitation methods of yellow cake are intensively examined. It was suggested that the raffinate-recycle in the leaching of filtering stage could be reduced the environmental contamination and the peroxide precipitation technique was applicable to improve the purity of yellow cake. The mechanism and conditions the third phase formation are thoroughly studied and confirmed by chemical analysis of the third phase actually formed during the operation of pilot plant. The major constituents of the third phase are polyanions such as PMosub(12)Osub(40)sup(3-) or SiMosub(12)Osub(40)sup(4-). And the formation of these polyanions could be reduced by the control of redox potential and the addition of modifier. (Author)

  16. Ore-processing technology and the uranium supply outlook

    International Nuclear Information System (INIS)

    James, H.E.; Simonsen, H.A.

    1978-01-01

    The subject is covered in sections, as follows: the resource base (uranium content of rocks, regional distribution of Western World uranium); ore types (distribution of Western World uranium, by ore types, response to ore-processing); constraints on expansion in traditional uranium areas (defined for this paper as the sandstone deposits of the U.S.A. and the quartz-pebble conglomerates of the Witwatersrand and Elliot Bay areas, all other deposits being referred to as new uranium areas). Sections then follow dealing in detail with the processing of deposits in U.S.A., South Africa, Canada, Niger, Australia, South West Africa, Greenland. More general sections follow on: shale, lignite and coal deposits, calcrete deposits. Finally, there are sections on: uranium as a by-product; uranium from very low-grade resources; constraints on expansion rate for production facilities. (U.K.)

  17. Emerging industrial processes for low grade rare earth mineral concentrates

    International Nuclear Information System (INIS)

    Soldenhoff, Karin; Ho, Elizabeth

    2015-01-01

    Historically rare earth recovery has mainly been derived from the processing of monazite, bastnasite and xenotime containing ores amenable to beneficiation, yielding high grade mineral concentrates. A notable exception is the recovery of heavy rare earths from ionic clays in Southern China. Recently, projects are being proposed to treat a range of mineral concentrates which tend to be lower grade with wide ranging modal mineralogy for rare earths and associated gangue minerals. This has a significant impact on processing routes. This paper discusses processes proposed for emerging rare earth producers and how different projects have responded to particular challenges including: Control of phosphorous due to the presence of xenotime or monazite type minerals; Control of phosphorous due to the presence of rare earth containing apatite; Rare earth recovery from polymetallic ores; Control of radionuclides in rare earth processing, etc.

  18. Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

    Science.gov (United States)

    Henda, R; Hermas, A; Gedye, R; Islam, M R

    2005-01-01

    A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

  19. Ore petrography of a sedimentary uranium deposit, Live Oak County, Texas

    International Nuclear Information System (INIS)

    Bomber, B.J.; Ledger, E.B.; Tieh, T.T.

    1986-01-01

    Samples from the McLean 5 open-pit uranium mine, a small high-grade deposit located along a normal fault in the Miocene Oakville sandstone of Live Oak County, Texas, have been studied for uranium abundance, distribution, and nature of occurrence on the microscopic level. The host sandstone is composed of quartz, feldspars, and volcanic rock fragments, cemented by sparry calcite. Authigenic minerals include iron disulfide minerals (dominantly pyrite and some marcasite) and small amounts of clays, Ti oxides, and opal. High-grade ore (to 3% U) occurs along the fault, decreasing to less than 1,000 ppm within 10 m from the fault. The ore mineral is amorphous pitchblende and exhibits botryoidal morphology. The microscopic occurrence of uranium, documented by fission-track mapping of petrographic thin sections, is presented in detail. Uranium occurs abundantly as grain coatings and fillings in intergranular spaces in samples with high uranium content, where calcite cement has been partially or totally leached as mineralization proceeded. Lesser amounts are adsorbed onto leucoxene (microcrystalline anatase), mud clasts, and altered igneous rock fragments. Adsorbed uranium is the major code of occurrence in samples, with lower uranium contents farther from the orebody. Textural relations indicate that iron sulfides formed both before and after mineralization. Initial mineralization was by adsorption onto aggregates of fine particles of Ti oxide and clay minerals of various origins. With dissolution of cement and continued uranium influx, uranium precipitated as grain coatings and pore fillings

  20. Immunohistochemical differentiation of high-grade prostate carcinoma from urothelial carcinoma.

    Science.gov (United States)

    Chuang, Ai-Ying; DeMarzo, Angelo M; Veltri, Robert W; Sharma, Rajni B; Bieberich, Charles J; Epstein, Jonathan I

    2007-08-01

    The histologic distinction between high-grade prostate cancer and infiltrating high-grade urothelial cancer may be difficult, and has significant implications because each disease may be treated very differently (ie, hormone therapy for prostate cancer and chemotherapy for urothelial cancer). Immunohistochemistry of novel and established prostatic and urothelial markers using tissue microarrays (TMAs) were studied. Prostatic markers studied included: prostate-specific antigen (PSA), prostein (P501s), prostate-specific membrane antigen (PSMA), NKX3.1 (an androgen-related tumor suppressor gene), and proPSA (pPSA) (precursor form of PSA). "Urothelial markers" included high molecular weight cytokeratin (HMWCK), p63, thrombomodulin, and S100P (placental S100). TMAs contained 38 poorly differentiated prostate cancers [Gleason score 8 (n=2), Gleason score 9 (n=18), Gleason score 10 (n=18)] and 35 high-grade invasive urothelial carcinomas from radical prostatectomy and cystectomy specimens, respectively. Each case had 2 to 8 tissue spots (0.6-mm diameter). If all spots for a case showed negative staining, the case was called negative. The sensitivities for labeling prostate cancers were PSA (97.4%), P501S (100%), PSMA (92.1%), NKX3.1 (94.7%), and pPSA (94.7%). Because of PSA's high sensitivity on the TMA, we chose 41 additional poorly differentiated primary (N=36) and metastatic (N=5) prostate carcinomas which showed variable PSA staining at the time of diagnosis and performed immunohistochemistry on routine tissue sections. Compared to PSA, which on average showed 18.8% of cells with moderate to strong positivity, cases stained for P501S, PSMA, and NKX3.1 had on average 42.5%, 53.7%, 52.9% immunoreactivity, respectively. All prostatic markers showed excellent specificity. HMWCK, p63, thrombomodulin, and S100P showed lower sensitivities in labeling high-grade invasive urothelial cancer in the TMAs with 91.4%, 82.9%, 68.6%, and 71.4% staining, respectively. These urothelial

  1. Predicting Freshman Grade Point Average From College Admissions Test Scores and State High School Test Scores

    OpenAIRE

    Koretz, Daniel; Yu, C; Mbekeani, Preeya Pandya; Langi, M.; Dhaliwal, Tasminda Kaur; Braslow, David Arthur

    2016-01-01

    The current focus on assessing “college and career readiness” raises an empirical question: How do high school tests compare with college admissions tests in predicting performance in college? We explored this using data from the City University of New York and public colleges in Kentucky. These two systems differ in the choice of college admissions test, the stakes for students on the high school test, and demographics. We predicted freshman grade point average (FGPA) from high school GPA an...

  2. Filtration aids in uranium ore processing

    International Nuclear Information System (INIS)

    Ford, H.L.; Levine, N.M.; Risdon, A.R.

    1975-01-01

    A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

  3. Health-related quality of life of long-term high-grade glioma survivors

    NARCIS (Netherlands)

    Bosma, Ingeborg; Reijneveld, Jaap C.; Douw, Linda; Vos, Maaike J.; Postma, Tjeerd J.; Aaronson, Neil K.; Muller, Martin; Vandertop, W. Peter; Slotman, Ben J.; Taphoorn, Martin J. B.; Heimans, Jan J.; Klein, Martin

    2009-01-01

    The objective of this study was to compare the health-related quality of life (HRQOL) of long-term to short-term high-grade glioma (HGG) survivors, determine the prognostic value of HRQOL for overall survival, and determine the effect of tumor recurrence on HRQOL for long-term survivors. Following

  4. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type

    NARCIS (Netherlands)

    Costa, A.F.; Altemani, A.; Vékony, H.; Bloemena, E.; Fresno, F.; Suárez, C.; Llorente, J.L.; Hermsen, M.

    2010-01-01

    Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACCHGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGTis generally considered to be an aggressive variant of ACC, even more

  5. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type

    NARCIS (Netherlands)

    Costa, A.F.; Altemani, A.; Vékony, H.; Bloemena, E.; Fresno, F.; Suárez, C.; Llorente, J.L.; Hermsen, M.

    2011-01-01

    Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more

  6. Prevention of Ovarian High-Grade Serous Carcinoma by Elucidating Its Early Changes

    Science.gov (United States)

    2014-10-01

    serous ovarian cancer carcinogenesis. Sophia HL George, Ramlogan Sowamber, Anca Milea, Noor Salman and Patricia Shaw. September 2014. Masha Rivkin Ovarian...in mesenchymal-to-epithelial transition during high-grade serous carcinogenesis. Masha Rivkin Ovarian Cancer Symposium September 2014, Seattle WA

  7. Profiles of Genomic Instability in High-Grade Serous Ovarian Cancer Predict Treatment Outcome

    DEFF Research Database (Denmark)

    Wang, Zhigang C.; Birkbak, Nicolai Juul; Culhane, Aedín C.

    2012-01-01

    Purpose: High-grade serous cancer (HGSC) is the most common cancer of the ovary and is characterized by chromosomal instability. Defects in homologous recombination repair (HRR) are associated with genomic instability in HGSC, and are exploited by therapy targeting DNA repair. Defective HRR cause...

  8. Symptoms and problems in the end-of-life phase of high-grade glioma patients

    NARCIS (Netherlands)

    Sizoo, Eefje M.; Braam, Lies; Postma, Tjeerd J.; Pasman, H. Roeline W.; Heimans, Jan J.; Klein, Martin; Reijneveld, Jaap C.; Taphoorn, Martin J. B.

    2010-01-01

    Despite multimodal treatment, it is not possible to cure high-grade glioma (HGG) patients. Therefore, the aim of treatment is not only to prolong life, but also to prevent deterioration of health-related quality of life as much as possible. When the patient's condition declines and no further tumor

  9. High-grade malignant transformation of a radiation-naïve nasopharyngeal angiofibroma.

    Science.gov (United States)

    Allensworth, Jordan J; Troob, Scott H; Lanciault, Christian; Andersen, Peter E

    2016-04-01

    Nasopharyngeal angiofibromas are typically considered benign vascular neoplasms, with descriptions of high-grade sarcomatous change found only in lesions with prior radiotherapy. We describe the first reported case of high-grade malignant change in a nasopharyngeal angiofibroma naive to radiation. A 45-year-old man presented with left-sided nasal congestion and fullness and was found to have a left-sided nasopharyngeal mass with intracranial extension on CT scan. A biopsy of the mass revealed nasopharyngeal angiofibroma. The patient opted for MRI surveillance, which revealed interval growth 3 years later. Decompression surgery revealed only angiofibroma, but resection 9 months later demonstrated high-grade sarcoma and concomitant angiofibroma. The patient had residual disease which progressed through chemoradiation, and is now pursuing clinical trial enrollment. Malignant transformation of nasopharyngeal angiofibroma is extremely rare. As highlighted by this report, high-grade undifferentiated lesions may arise in tumors without previous radiation. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2425-E2427, 2016. © 2016 Wiley Periodicals, Inc.

  10. Middle Grades to High School: Mending a Weak Link. Research Brief.

    Science.gov (United States)

    Cooney, Sondra; Bottoms, Gene

    This research brief describes a study of the readiness for high school of eighth-graders who participated in the Southern Regional Education Board's (SREB) Middle Grades Assessment in spring 2000. The assessment included testing in reading, math, and science, and surveys of students and teachers. Following the 2000-01 school year, SREB gathered…

  11. Survival and prognostic factors at time of diagnosis in high-grade appendicular osteosarcoma

    DEFF Research Database (Denmark)

    Colding-Rasmussen, Thomas; Thorn, Andrea Pohly; Horstmann, Peter

    2018-01-01

    BACKGROUND: Survival of patients with high-grade osteosarcoma (HOS), the most common primary bone cancer, has not improved significantly the last 30 years and the disease remains a major challenge. The purpose of this study is to evaluate survival in relation to prognostic factors at time of diag...

  12. High School Grade Inflation from 2004 to 2011. ACT Research Report Series, 2013 (3)

    Science.gov (United States)

    Zhang, Qian; Sanchez, Edgar I.

    2013-01-01

    This study explores inflation in high school grade point average (HSGPA), defined as trend over time in the conditional average of HSGPA, given ACT® Composite score. The time period considered is 2004 to 2011. Using hierarchical linear modeling, the study updates a previous analysis of Woodruff and Ziomek (2004). The study also investigates…

  13. The end-of-life phase of high-grade glioma patients: a systematic review

    NARCIS (Netherlands)

    Sizoo, Eefje M.; Pasman, H. Roeline W.; Dirven, Linda; Marosi, Christine; Grisold, Wolfgang; Stockhammer, Günther; Egeter, Jonas; Grant, Robin; Chang, Susan; Heimans, Jan J.; Deliens, Luc; Reijneveld, Jaap C.; Taphoorn, Martin J. B.

    2014-01-01

    High-grade gliomas (HGG) are rare and incurable; yet, these neoplasms result in a disproportionate share of cancer morbidity and mortality. Treatment of HGG patients is directed not merely towards prolonging life but also towards quality of life, which becomes the major goal in the end of life

  14. The end-of-life phase of high-grade glioma patients: a systematic review

    NARCIS (Netherlands)

    Sizoo, E.M.; Pasman, H.R.W.; Dirven, L.; Marosi, C.; Grisold, W.; Stockhammer, G.; Egeter, J.; Grant, R.; Chang, S.; Heimans, J.J.; Deliens, L.; Reijneveld, J.C.; Taphoorn, M.J.B.

    2014-01-01

    Background: High-grade gliomas (HGG) are rare and incurable; yet, these neoplasms result in a disproportionate share of cancer morbidity and mortality. Treatment of HGG patients is directed not merely towards prolonging life but also towards quality of life, which becomes the major goal in the end

  15. Connective tissue growth factor as a novel therapeutic target in high grade serous ovarian cancer.

    Science.gov (United States)

    Moran-Jones, Kim; Gloss, Brian S; Murali, Rajmohan; Chang, David K; Colvin, Emily K; Jones, Marc D; Yuen, Samuel; Howell, Viive M; Brown, Laura M; Wong, Carol W; Spong, Suzanne M; Scarlett, Christopher J; Hacker, Neville F; Ghosh, Sue; Mok, Samuel C; Birrer, Michael J; Samimi, Goli

    2015-12-29

    Ovarian cancer is the most common cause of death among women with gynecologic cancer. We examined molecular profiles of fibroblasts from normal ovary and high-grade serous ovarian tumors to identify novel therapeutic targets involved in tumor progression. We identified 2,300 genes that are significantly differentially expressed in tumor-associated fibroblasts. Fibroblast expression of one of these genes, connective tissue growth factor (CTGF), was confirmed by immunohistochemistry. CTGF protein expression in ovarian tumor fibroblasts significantly correlated with gene expression levels. CTGF is a secreted component of the tumor microenvironment and is being pursued as a therapeutic target in pancreatic cancer. We examined its effect in in vitro and ex vivo ovarian cancer models, and examined associations between CTGF expression and clinico-pathologic characteristics in patients. CTGF promotes migration and peritoneal adhesion of ovarian cancer cells. These effects are abrogated by FG-3019, a human monoclonal antibody against CTGF, currently under clinical investigation as a therapeutic agent. Immunohistochemical analyses of high-grade serous ovarian tumors reveal that the highest level of tumor stromal CTGF expression was correlated with the poorest prognosis. Our findings identify CTGF as a promoter of peritoneal adhesion, likely to mediate metastasis, and a potential therapeutic target in high-grade serous ovarian cancer. These results warrant further studies into the therapeutic efficacy of FG-3019 in high-grade serous ovarian cancer.

  16. Symptoms and medication management in the end of life phase of high-grade glioma patients

    NARCIS (Netherlands)

    Koekkoek, J.A.F.; Dirven, L.; Sizoo, E.M.; Pasman, H.R.W.; Heimans, J.J.; Postma, T.J.; Deliens, L.; Grant, R.; McNamara, S.; Stockhammer, G.; Medicus, E.; Taphoorn, M.J.B.; Reijneveld, J.C.

    2014-01-01

    During the end of life (EOL) phase of high-grade glioma (HGG) patients, care is primarily aimed at reducing symptom burden while maintaining quality of life as long as possible. In this study, we evaluated the prevalence of symptoms and medication management in HGG patients during the EOL phase. We

  17. Acid curing and baking of bastnasite ore and concentrate

    International Nuclear Information System (INIS)

    Topkaya, Y.; Akkurt, S.

    1998-01-01

    Full text: In this study, the hydrometallurgical evaluation of a rare earth ore as well as a concentrate obtained from this was done at laboratory. For the mentioned study, a bastnasite type rare earth ore located in Beylikahir in Turkey was used. The total rare earth oxide (REO) content of the deposit was estimated to be 1 million tons with an average concentration of 3.42%REO. The rare earths were contained in bastnasite mineral. The other constituents of the ore were calcium fluoride (52.5%), barite (25.4%), calcite (2.8%) and minor amounts of thorium, iron, manganese, etc. The bastnasite mineral occurred either as cement material between fluoride and barite particles or as intimately associated with these minerals. The rare earth elements were enriched considerably in sub-sieve sizes. After extensive research about the physical concentration of this ore, two different metallurgical routes were followed for the extraction of REE from the ore itself or the preconcentrate obtained by attrition scrubbing and desliming by cyclones. In order to increase the grade of the concentrate, upgrading of the preconcentrate by multigravity was also tried. The two metallurgical routes tested were: Sulphuric acid curing and water leaching; Sulphuric acid baking and subsequent water leaching. The results of the leaching experiments were found to be quite promising. Leach recoveries up to 90% were easily obtainable. In the case of acid baking, hydrofluoric acid recover as a by-product was also possible

  18. Highly transparent vanadium oxide-graded indium zinc oxide electrodes for flexible organic solar cells

    International Nuclear Information System (INIS)

    Ko, Eun-Hye; Kim, Han-Ki

    2016-01-01

    We investigated characteristics of amorphous V_2O_5-graded InZnO (IZO) films to use as a flexible anode for flexible organic solar cells (FOSCs). Graded sputtering of the V_2O_5 layer on the IZO layer produced V_2O_5-graded IZO anodes (VGIZO) with a sheet resistance of 42.14 Ω/square, a resistivity of 6.32 × 10"−"4 Ω cm, and an optical transmittance of 82.15%, as well as good mechanical flexibility. In addition, the VGIZO electrode showed a greater work function of 5.2 eV than that (4.9 eV) of an IZO anode, which is beneficial for hole extraction from an organic active layer. Due to the higher work function of the VGIZO electrodes, FOSCs fabricated on the flexible VGIZO anode exhibited a higher power conversion efficiency 2.753% than that of FOSCs on the IZO anode. This indicates that the V_2O_5 graded sputtering is a promising technique to increase the work function of the IZO anode without change in sheet resistance and transmittance. - Highlights: • Transparent and flexible V_2O_5 graded IZO (VGIZO) electrodes. • High work function of VGIZO electrodes • The VGIZO film is a promising flexible anode for flexible organic solar cells.

  19. Adenoid cystic carcinoma of the breast, high grade with basal phenotype, literature review

    Directory of Open Access Journals (Sweden)

    Enaam Junainah

    Full Text Available Adenoid cystic carcinoma (ACC is a rare type of breast carcinoma resembling adenoid cystic carcinoma of other sites. this type of tumors usually characterized by the exhibiting dual cell population of luminal and basaloid with specific growth pattern Most of these sub types are triple-negative with basal-like breast features (tumors that are devoid of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression, and express basal cell markers, they are usually low-grade but can be high grade, clinical behavior is indolent despite the nuclear grade, lymph node involvement or distant metastases which is rarely occur. Treatment is either simple mastectomy or lumpectomy. Chemotherapy, radiation and hormonal treatment have limited used in those cases. Keywords: Adenoid cystic carcinoma, Breast, Triple-negative and basal-like phenotype

  20. Characterizing the economic value of an epithermal Au-Ag ore with Laser Induced Breakdown Spectroscopy (LIBS)

    NARCIS (Netherlands)

    Dalm, M.; Buxton, M.W.N.

    2016-01-01

    LIBS was applied to 19 Au-Ag ore samples to investigate if this technique can be used to distinguish between economic and sub-economic ore either by direct detection of these elements or by using other elements as indicators. However, the Au and Ag grades of the samples are below the detection limit

  1. Microbial reduction of iron ore

    Science.gov (United States)

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  2. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

    International Nuclear Information System (INIS)

    Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

    1994-03-01

    The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique

  3. Modeling drying of iron ore pellets

    OpenAIRE

    Ljung, Anna-Lena

    2010-01-01

    Iron ore pellets are a highly refined product supplied to the steel making industry for use in blast furnaces or direct reduction processes. The use of pellets offers many advantages such as customer adopted products, transportability and mechanical strength yet the production is time and energy consuming. Being such, there is a natural driving force to enhance the pelletization in order to optimize production and improve quality. The aim with this thesis is to develop numerical models with w...

  4. Textural analysis of pre-therapeutic [18F]-FET-PET and its correlation with tumor grade and patient survival in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Thomas; Hiob, Daniela; Wester, Hans-Juergen [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [Klinikum Rechts der Isar der TU Muenchen, Neurosurgic Department, Munich (Germany); Schlegel, Juergen [Klinikum Rechts der Isar der TU Muenchen, Institute of Pathology and Neuropathology, Munich (Germany); Bette, Stefanie [Klinikum Rechts der Isar der TU Muenchen, Neuroradiologic department, Munich (Germany); Foerster, Stefan [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Klinikum Rechts der Isar der TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-01-15

    Amino acid positron emission tomography (PET) with [18F]-fluoroethyl-L-tyrosine (FET) is well established in the diagnostic work-up of malignant brain tumors. Analysis of FET-PET data using tumor-to-background ratios (TBR) has been shown to be highly valuable for the detection of viable hypermetabolic brain tumor tissue; however, it has not proven equally useful for tumor grading. Recently, textural features in 18-fluorodeoxyglucose-PET have been proposed as a method to quantify the heterogeneity of glucose metabolism in a variety of tumor entities. Herein we evaluate whether textural FET-PET features are of utility for grading and prognostication in patients with high-grade gliomas. One hundred thirteen patients (70 men, 43 women) with histologically proven high-grade gliomas were included in this retrospective study. All patients received static FET-PET scans prior to first-line therapy. TBR (max and mean), volumetric parameters and textural parameters based on gray-level neighborhood difference matrices were derived from static FET-PET images. Receiver operating characteristic (ROC) and discriminant function analyses were used to assess the value for tumor grading. Kaplan-Meier curves and univariate and multivariate Cox regression were employed for analysis of progression-free and overall survival. All FET-PET textural parameters showed the ability to differentiate between World Health Organization (WHO) grade III and IV tumors (p < 0.001; AUC 0.775). Further improvement in discriminatory power was possible through a combination of texture and metabolic tumor volume, classifying 85 % of tumors correctly (AUC 0.830). TBR and volumetric parameters alone were correlated with tumor grade, but showed lower AUC values (0.644 and 0.710, respectively). Furthermore, a correlation of FET-PET texture but not TBR was shown with patient PFS and OS, proving significant in multivariate analysis as well. Volumetric parameters were predictive for OS, but this correlation did not

  5. ERBB2 mutations associated with solid variant of high-grade invasive lobular breast carcinomas.

    Science.gov (United States)

    Deniziaut, Gabrielle; Tille, Jean Christophe; Bidard, François-Clément; Vacher, Sophie; Schnitzler, Anne; Chemlali, Walid; Trémoulet, Laurence; Fuhrmann, Laetitia; Cottu, Paul; Rouzier, Roman; Bièche, Ivan; Vincent-Salomon, Anne

    2016-11-08

    ERBB2 and ERBB3 somatic gain-of-function mutations, which may be targeted by anti-ERBB2 therapies, were reported by high-throughput sequencing studies in 1% and 2% of invasive breast cancers respectively. Our study aims to determine ERBB2 and ERBB3 mutations frequencies in grade 3 and/or ERBB2-positive invasive lobular breast carcinomas (ILC). All the 529 ILC surgically-excised registered at Institut Curie in the years 2005 to 2008 were reviewed. Thirty-nine grade 3 ERBB2-negative ILC and 16 ERBB2-positive ILC were retrieved and subjected to Sanger sequencing of the ERBB2 and ERBB3 activation mutation hotspots (ERBB2: exons 8, 17, 19, 20, 21; ERBB3: exons 3, 6, 7, 8). Among the 39 grade 3 ERBB2-negative ILC, six tumors were found to have at least one detectable ERBB2 activating mutation (incidence rate: 15%, 95%CI [4%-27%]). No ERBB2 mutation was found among the 16 ERBB2-positive ILC. No ERBB3 mutation was found in any of the 55 ILC. ERBB2 mutations were statistically associated with solid ILC features (p=0.01). Survival analyses showed no significant prognostic impact of ERBB2 mutations. Our study demonstrates that high grade ERBB2-negative ILC display a high frequency of ERBB2 mutations, and should be subjected to systematic genetic screening.

  6. High-grade renal injuries are often isolated in sports-related trauma.

    Science.gov (United States)

    Patel, Darshan P; Redshaw, Jeffrey D; Breyer, Benjamin N; Smith, Thomas G; Erickson, Bradley A; Majercik, Sarah D; Gaither, Thomas W; Craig, James R; Gardner, Scott; Presson, Angela P; Zhang, Chong; Hotaling, James M; Brant, William O; Myers, Jeremy B

    2015-07-01

    Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. We identified patients with AAST grades III-V blunt renal injuries from four level 1 trauma centres across the United States between 1/2005 and 1/2014. Patients were divided into "Sport" or "Non-sport" related groups. Outcomes included rates of hypotension (systolic blood pressure 110bpm), concomitant abdominal injury, and procedural/surgical intervention between sports and non-sports related injury. 320 patients met study criteria. 18% (59) were sports-related injuries with the most common mechanisms being skiing, snowboarding and contact sports (25%, 25%, and 24%, respectively). Median age was 24 years for sports and 30 years for non-sports related renal injuries (p=0.049). Males were more commonly involved in sports related injuries (85% vs. 72%, p=0.011). Median injury severity score was lower for sports related injuries (10 vs. 27, pinjury scale scores. Sports related trauma was more likely to be isolated without other significant injury (69% vs. 39% (psports and non-sports renal injuries (p=0.30). Sports injuries had lower transfusion (7% vs. 47%, psports vs. 18% non-sports, p=0.95). High-grade sports-related blunt renal trauma is more likely to occur in isolation without other abdominal or thoracic injuries and clinicians must have a high suspicion of renal injury with significant blows to the flank during sports activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Geochemistry and the origin of the Mamouniyeh iron ore-terra rossa deposit, Markazi Province - Iran

    Directory of Open Access Journals (Sweden)

    Marziyeh Mahboubiyan Fard

    2017-11-01

    chert and minor jasper. Some secondary dolomite and calcite, filling the fractures and open spaces are found. Clay minerals are also minor constituents of the ore. The remaining fossils of green-blue algae indicate the conditions of iron deposition and effective biological processes in oxidizing Fe+2 and creation of new oxide minerals in a sedimentary basin. XRD studies show that tetraferriannite, hisingerite, barite, dolomite and calcite are present in addition to dominant hematite and quartz minerals. Hisingerite is formed in sedimentary iron deposits during hydrothermal alteration (Whelan and Goldich., 1961. Tetraferriannite occurs in low grade iron formations (Miyano, 1982. Structurally, the mineralization is controlled by a tectonic zone in which abundant breccias and faults are well found. The amount of Fe2O3 ranges between 11.62% and 65.73%, with an average value of 31% Fe2O3. The amounts of Cr (3-95 ppm and Zr (<5-29 ppm are low; while, the deposit contains a moderate amount of V (26-189 ppm and high concentrations of Zn (28-218 ppm, Sr (66-1462 ppm and Ba (62-5511 ppm. The concentration of REEs shows that total amount of these elements is variable and it falls in the range of 2.34-12.74 ppm. The amount of LREEs falls in the range of 1.66-11.94 ppm and that of HREEs falls in 0.21-2.22 ppm. These values clearly indicate the enrichment of ore in LREEs relative to HREEs. The Eu anomaly (Eu/Eu* lies in the range of 1.32-10.2, indicating positive Eu anomalies. The Ce anomalies (Ce/Ce* fall in the range of 0.076-0.52, suggesting negative anomaly. Discussion The low concentration of Cr and Zr, and high values of V, Zn and Sr in the ore suggest that mineralization is related to submarine volcanic activities. Geochemical data, including chondrite-normalized REE patterns, indicate that seafloor hydrothermal fluids are the most probable source for mineralizing solutions. The ∑(Cu+Co+Ni vs. ∑REE diagram also indicates the role of deep sea hydrothermal fluids in the

  8. High success rate with new modified endoscopic treatment for high-grade VUR: A pilot study with preliminary report.

    Science.gov (United States)

    Asgari, S A; Asl, A S; Safarinejad, M R; Ghanaei, M M

    2016-04-01

    Despite the benefits of the minimally invasive endoscopic treatment for vesicoureteral reflux (VUR) it has a major drawback which is low success rate in high grade VUR. For overcoming this problem, we introduce a new modified technique of endoscopic treatment called periureteral injection technique (PIT). In a prospective study a total of 37 ureters in 19 boys and 14 girls were treated, including 3 bilateral cases. Of 37 units, 30 (81.1%) had grade IV and 7 (18.9%) had grade V primary VUR (18 right, 13 left and 3 bilateral units). Subureteral injection of Vantris(®) was done at the 5-o'clock and 7-o'clock positions in which the direction of injecting needles were almost parallel. Pre- and post-operative evaluation included urinalysis, urinary tract ultrasonography, voiding cystourethrography (VCUG), dimercaptosuccinic acid scan and urodynamic studies. The median age was 38 months (range 8-125). At 6 months follow up period confirmed with VCUG, the VUR has been disappeared in 34 (91.8%) units and 3 units [2 (5.4%) grade II and 1 (2.7%) had grade III)] had downgraded VUR. Complications included early fever due to urinary tract infection in 1 children, transient dysuria in 2 patients and low back pain in one patient (Summary Table). The success rate of PIT for treatment of high grade VUR is high. However, further studies with more patients and longer follow up periods are needed to draw final conclusion. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  9. Prevalence of Human Papillomavirus Genotypes Among Women With High-Grade Cervical Lesions in Beijing, China

    Science.gov (United States)

    Xiao, Meizhu; Xu, Qiuxiang; Li, Hongyan; Gao, Huiqiao; Bie, Yachun; Zhang, Zhenyu

    2016-01-01

    Abstract The aim of the study is to investigate the prevalence of high-risk human papillomavirus (hr-HPV) genotypes among Han women with high-grade cervical lesions in Beijing, China. Cervical cell specimens from patients with histopathologically confirmed cervical lesions at 7 hospitals in Beijing were examined with a validated HPV kit for 13 hr-HPV genotypes during the study period. The patients were divided into a low-grade cervical lesions group (cervical intraepithelial neoplasia grade 1, CIN1) and a high-grade cervical lesions group (CIN2+, including cervical intraepithelial neoplasia grade 2, CIN2; cervical intraepithelial neoplasia grade 3, CIN3; squamous cervical cancer, SCC; and adenocarcinoma of the cervix, ACC) based on the histopathology results. A total of 2817 eligible patients were enrolled, including 610 cases identified as CIN1 and 2207 as CIN2+. The hr-HPV positive rates in the CIN1 and CIN2+ groups were 78.2% (477/610) and 93.3% (2060/2207), respectively. The most frequently detected genotypes were HPV16, 58, 52 and18 in the CIN1 group and HPV16, 58, 33, and 52 in the CIN2+ group, in descending order of prevalence. In addition, the prevalence of HPV18 among the patients with ACC was 28.6% (14/49), significantly >7.2% (54/752) prevalence among the SCC patients (P HPV infections gradually deceased to 44.2% in the CIN2 patients, 36.7% in the CIN3 patients, and 35.3% in the cervical cancer (CC) patients, which included SCC and ACC patients. In cases of multiple hr-HPV infections in the CIN2+ group, double infections accounted for ∼76.6%, and HPV16+58, HPV16+52, and HPV16+18 were the most common combinations, in descending order. The most frequent combination for triple infections was HPV16+58+31, with a rate of 4.2%. The highest positive rate occurred in the ≤24 year-old group for all types of cervical lesions. The prevalence of HPV genotypes in the targeted population with high-grade cervical lesions differs from that of other countries. This

  10. Beneficiation studies of Bajaur manganese ore by different processing techniques

    International Nuclear Information System (INIS)

    Riaz, M.; Khan, F.U.; Yamin, A.; Bilquees, R.; Muhammad, N.

    2010-01-01

    The manganese ore of Bajaur Agency of Pakistan was subjected to flotation, heavy medium separation, gravity concentration and magnetic separation techniques for beneficiation. The original composition of the manganese ore was 45.56% Mn , 4% Fe/sub 2/O/sub 3/, 40% SiO/sub 2/. The Mn content was raised to a maximum 48.76 % in the concentrate with the recovery of 67.78 % through flotation technique. Other techniques rendered marginal increase in Mn concentration against the theoretical possibility of substantial enrichment by rejecting the 20 % gangue minerals. The separation of manganese minerals from associated gangue was difficult, due to mineralogical complexity of the ore, extreme fineness of the particle size, texture and minerals intergrowth. High Mn/Fe ratio, phosphorus, and silica contents were within tolerable limits for utilisation of the ore in ferro-manganese production. (author)

  11. Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

    Science.gov (United States)

    Otsuki, A.; Yue, C.

    2017-07-01

    This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

  12. Rad51 expression levels predict synthetic lethality and metastatic potential in high grade breast cancers

    International Nuclear Information System (INIS)

    Wiegmans, A.P.; Al-Ejeh, F.; Khanna, K.K.

    2012-01-01

    Among women with breast cancer, 30-40% will develop metastatic disease and only achieve an overall survival of less than 5 years. Despite new-targeted therapy, breast tumors that harbour similar histology or molecular phenotype differ in their response to treatment. To uncover potential new therapeutic targets and improve outcome, we performed data mining of cancer micro array databases. We found that high expression of the homologous recombination protein, RAD51, was significantly associated with high-grade breast cancer, aggressive subtypes and increased risk of metastasis. We confirmed using immunohistochemistry that RAD5 1 was highly expressed in metastatic tumours and high-grade triple negative, HER2+ and luminal-B tumours. This provided a rationale for targeting RAD5 1 in high-grade, therapy-resistant breast cancers. Here, we report for the first time preclinical evaluation of RAD5 1 as a therapeutic target. We found that, in-vitro high RAD5 expressing cell lines were resistant to PARP inhibitor while knockdown reversed this resistance. In-vivo, knockdown of RAD5 1 inhibited metastatic progression using a syngeneic breast cancer model and the seeding of human xenografts to distant sites, including brain and lung. Concurrent PARP inhibition reduced primary tumor growth and delayed metastasis supporting synthetic lethality in-vivo. Together these insights provide pre-clinical data demonstrating RAD5 1 as a new biomarker and potential therapeutic target against aggressive metastatic breast cancer. (author)

  13. A Pilot Feasibility Study of Oral 5-Fluorocytosine and Genetically-Modified Neural Stem Cells Expressing E.Coli Cytosine Deaminase for Treatment of Recurrent High Grade Gliomas

    Science.gov (United States)

    2017-11-07

    Adult Anaplastic Astrocytoma; Recurrent Grade III Glioma; Recurrent Grade IV Glioma; Adult Anaplastic Oligodendroglioma; Adult Brain Tumor; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Mixed Glioma; Recurrent Adult Brain Tumor; Adult Anaplastic Oligoastrocytoma; Recurrent High Grade Glioma

  14. Low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion: a category with an increased outcome of high-grade lesions: use as a quality assurance measure.

    Science.gov (United States)

    Nishino, Ha T; Wilbur, David C; Tambouret, Rosemary H

    2012-08-01

    "Low-grade squamous intraepithelial lesion (LSIL), cannot exclude high-grade squamous intraepithelial lesion" (LSIL-H) is an increasingly used, equivocal interpretive category in gynecologic cytology. In an effort to evaluate its potential usefulness as a measure of quality assurance, we studied patterns of use of the LSIL-H diagnosis compared with "LSIL" and "high-grade squamous intraepithelial lesion" (HSIL) with corresponding histologic outcomes for 10 cytopathologists in our practice. In our laboratory, while the overall rate of associated cervical intraepithelial neoplasia 2 or greater on histologic follow-up for LSIL-H was intermediate between that of LSIL and HSIL, the outcomes for individual cytopathologists varied widely. Monitoring this particular utilization-outcome data with periodic confidential feedback to individual cytopathologists offers an opportunity for practice improvement within a laboratory and serves as an additional measure of quality assurance. These data may be useful for establishing and/or realigning the diagnostic criteria for this equivocal cytologic interpretation endorsed by a pathology practice.

  15. Iron isotope fractionation during hydrothermal ore deposition and alteration

    Science.gov (United States)

    Markl, Gregor; von Blanckenburg, Friedhelm; Wagner, Thomas

    2006-06-01

    Iron isotopes fractionate during hydrothermal processes. Therefore, the Fe isotope composition of ore-forming minerals characterizes either iron sources or fluid histories. The former potentially serves to distinguish between sedimentary, magmatic or metamorphic iron sources, and the latter allows the reconstruction of precipitation and redox processes. These processes take place during ore formation or alteration. The aim of this contribution is to investigate the suitability of this new isotope method as a probe of ore-related processes. For this purpose 51 samples of iron ores and iron mineral separates from the Schwarzwald region, southwest Germany, were analyzed for their iron isotope composition using multicollector ICP-MS. Further, the ore-forming and ore-altering processes were quantitatively modeled using reaction path calculations. The Schwarzwald mining district hosts mineralizations that formed discontinuously over almost 300 Ma of hydrothermal activity. Primary hematite, siderite and sulfides formed from mixing of meteoric fluids with deeper crustal brines. Later, these minerals were partly dissolved and oxidized, and secondary hematite, goethite and iron arsenates were precipitated. Two types of alteration products formed: (1) primary and high-temperature secondary Fe minerals formed between 120 and 300 °C, and (2) low-temperature secondary Fe minerals formed under supergene conditions (illustrates the potential of the new technique in deciphering ore formation and alteration processes. Isotope ratios are strongly dependent on and highly characteristic of fluid and precipitation histories. Therefore, they are less suitable to provide information on Fe sources. However, it will be possible to unravel the physico-chemical processes leading to the formation, dissolution and redeposition of ores in great detail.

  16. Applying Four Different Risk Models in Local Ore Selection

    International Nuclear Information System (INIS)

    Richmond, Andrew

    2002-01-01

    Given the uncertainty in grade at a mine location, a financially risk-averse decision-maker may prefer to incorporate this uncertainty into the ore selection process. A FORTRAN program risksel is presented to calculate local risk-adjusted optimal ore selections using a negative exponential utility function and three dominance models: mean-variance, mean-downside risk, and stochastic dominance. All four methods are demonstrated in a grade control environment. In the case study, optimal selections range with the magnitude of financial risk that a decision-maker is prepared to accept. Except for the stochastic dominance method, the risk models reassign material from higher cost to lower cost processing options as the aversion to financial risk increases. The stochastic dominance model usually was unable to determine the optimal local selection

  17. Flotation study on scheelite ore of chitral khyber pakhtoonkhwa, pakistan

    International Nuclear Information System (INIS)

    Bhatti, M.A.; Kazmi, K.R.; Mehmood, R.; Akram, A.

    2014-01-01

    The beneficiation of a siliceous scheelite ore of Chitral, Khyber Pakhtoonkhwa, Pakistan, was investigated by flotation process to determine the optimum conditions for obtaining maximum grade and recovery of the scheelite concentrate. The variables studied were including pH and pulp density maintained during conditioning, type and quantity of reagents added, conditioning time and froth collecting time. The results achieved were plotted against the grade and recovery of the rougher concentrate. Several methods of cleaning rougher concentrate were attempted. An ore initially containing 0.34% WO/sub 3/ was upgraded into a final concentrate assaying 64.66% WO/sub 3/ with 70.36% recovery. The tungsten concentrate obtained meets the specifications required to produce ferrotungsten and tungsten chemicals. (author)

  18. Complications of high grade liver injuries: management and outcomewith focus on bile leaks

    Directory of Open Access Journals (Sweden)

    Bala Miklosh

    2012-03-01

    Full Text Available Abstract Background Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to expect an increased risk of hepatic complications following trauma. The aim of the current study was to define hepatic related morbidity in patients sustaining high-grade hepatic injuries that could be safely managed non-operatively. Patients and methods This is a retrospective study of patients with liver injury admitted to Hadassah-Hebrew University Medical Centre over a 10-year period. Grade 3-5 injuries were considered to be high grade. Collected data included the number and types of liver-related complications. Interventions which were required for these complications in patients who survived longer than 24 hours were analysed. Results Of 398 patients with liver trauma, 64 (16% were found to have high-grade liver injuries. Mechanism of injury was blunt trauma in 43 cases, and penetrating in 21. Forty patients (62% required operative treatment. Among survivors 22 patients (47.8% developed liver-related complications which required additional interventional treatment. Bilomas and bile leaks were diagnosed in 16 cases post-injury. The diagnosis of bile leaks was suspected with abdominal CT scan, which revealed intraabdominal collections (n = 6, and ascites (n = 2. Three patients had continuous biliary leak from intraabdominal drains left after laparotomy. Nine patients required ERCP with biliary stent placement, and 2 required percutaneous transhepatic biliary drainage. ERCP failed in one case. Four angioembolizations (AE were performed in 3 patients for rebleeding. Surgical treatment was found to be associated with higher complication rate. AE at admission was associated with a significantly higher rate of biliary complications. There were 24 deaths (37%, the majority from uncontrolled haemorrhage (18 patients. There were only 2 hepatic-related mortalities due to liver failure

  19. Complications of high grade liver injuries: management and outcomewith focus on bile leaks.

    Science.gov (United States)

    Bala, Miklosh; Gazalla, Samir Abu; Faroja, Mohammad; Bloom, Allan I; Zamir, Gideon; Rivkind, Avraham I; Almogy, Gidon

    2012-03-23

    Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to expect an increased risk of hepatic complications following trauma. The aim of the current study was to define hepatic related morbidity in patients sustaining high-grade hepatic injuries that could be safely managed non-operatively. This is a retrospective study of patients with liver injury admitted to Hadassah-Hebrew University Medical Centre over a 10-year period. Grade 3-5 injuries were considered to be high grade. Collected data included the number and types of liver-related complications. Interventions which were required for these complications in patients who survived longer than 24 hours were analysed. Of 398 patients with liver trauma, 64 (16%) were found to have high-grade liver injuries. Mechanism of injury was blunt trauma in 43 cases, and penetrating in 21. Forty patients (62%) required operative treatment. Among survivors 22 patients (47.8%) developed liver-related complications which required additional interventional treatment. Bilomas and bile leaks were diagnosed in 16 cases post-injury. The diagnosis of bile leaks was suspected with abdominal CT scan, which revealed intraabdominal collections (n = 6), and ascites (n = 2). Three patients had continuous biliary leak from intraabdominal drains left after laparotomy. Nine patients required ERCP with biliary stent placement, and 2 required percutaneous transhepatic biliary drainage. ERCP failed in one case. Four angioembolizations (AE) were performed in 3 patients for rebleeding. Surgical treatment was found to be associated with higher complication rate. AE at admission was associated with a significantly higher rate of biliary complications. There were 24 deaths (37%), the majority from uncontrolled haemorrhage (18 patients). There were only 2 hepatic-related mortalities due to liver failure. A high complication rate following high-grade liver injuries should

  20. High-grade hemorrhoids requiring surgical treatment are common after laparoscopic ventral mesh rectopexy.

    Science.gov (United States)

    van Iersel, J J; Formijne Jonkers, H A; Verheijen, P M; Draaisma, W A; Consten, E C J; Broeders, I A M J

    2016-04-01

    To describe patients developing grade III and IV hemorrhoids requiring surgery after laparoscopic ventral mesh rectopexy (LVMR) and to explore the relationship between developing such hemorrhoids and recurrence of rectal prolapse after LVMR. All consecutive patients receiving LVMR at the Meander Medical Centre, Amersfoort, the Netherlands, between 2004 and 2013 were analyzed. Kaplan-Meier estimates were calculated for recurrences. A total of 420 patients underwent LVMR. Sixty-five of these patients (actuarial 5-year incidence 24.3, 95 % confidence interval (CI) 18.6-30.0) developed symptomatic grade III/IV hemorrhoids requiring stapled or excisional hemorrhoidectomy. Re-do surgery for recurrent grade III/IV hemorrhoids was required for 15 of the 65 patients (actuarial 5-year recurrence rate 40.6, 95 % CI 23.2-58.0) after the primary hemorrhoidectomy. Three of the 65 patients developed an external rectal prolapse (ERP) recurrence and eight an internal rectal prolapse (IRP) recurrence. This generated a 5-year recurrence rate of 25.3 % (95 % CI 0-53.9) for ERP recurrence and 24.4 % (95 % CI 9.1-39.7) for IRP recurrence. The rest of the LVMR cohort not receiving additional surgery for hemorrhoids (n = 355) showed significantly lower actuarial 5-year ERP (0.8 %, p = 0.011) and IRP (11 %, p = 0.020) recurrence rates. High-grade hemorrhoids requiring surgery may be common after LVMR. The development of high-grade hemorrhoids after LVMR might be considered a predictor of rectal prolapse recurrence.

  1. Colposcopic characteristics and Lugol׳s staining differentiate anal high-grade and low-grade squamous intraepithelial lesions during high resolution anoscopy

    Directory of Open Access Journals (Sweden)

    Naomi Jay

    2015-12-01

    Full Text Available Background: Anal squamous intraepithelial lesions (SIL and cancers are increased in immunocompromised populations. Based upon anatomic and histologic similarities, the cervix is used as the model for anal screening. During cervical colposcopy, acetic acid (AA and Lugol׳s staining (LS result in characteristic changes that help distinguish low-grade (LSIL from high-grade (HSIL. Lesion characteristics were evaluated for their ability to distinguish anal (aLSIL from anal (aHSIL during high-resolution anoscopy after application of AA and LS. Methods: AA-stained lesions were described using standard cervical colposcopic criteria. LS was then applied and lesions were characterized as Lugol׳s-negative (L−, Lugol׳s-partial (L+/−, or Lugol׳s positive (L+ and then biopsied. Biopsies were characterized as benign, squamous atypia, LSIL or HSIL. Results: 835 anal lesions were analyzed. Sensitivity and positive predictive value (PPV for aHSIL were highest for characteristics associated with cervical (cHSIL. L− was independently associated with aHSIL (OR=4.7, 95% CI=3.4–6.7. In multiple logistic regression analysis, significant predictors of aHSIL were flat contour (OR=2.24, 95% CI=1.3–3.8, mosaic pattern (OR=2.0, 95% CI=1.4–2.9, vascular punctation (OR=1.5, 95% CI=1.1–2.1 and L− (OR=2.3, 95% CI=1.5–3.4. L− staining improved the PPV of aHSIL almost twofold in lesions that otherwise had a colposcopic impression of LSIL. Conclusions: Evaluating acetowhite lesions for contour, surface, vascularity, and LS may maximize the likelihood of identifying aHSIL. Keywords: Anal, HSIL, High resolution anoscopy, Lugol׳s staining

  2. The allocation of gold production from multiple shafts feeding a common treatment plant using run-of-mine sampling of ore deliveries

    OpenAIRE

    Bartlett, H.E.; Korff, L.; Minnitt, R.C.A.

    2014-01-01

    Previously, the grade of ore at the shaft head was taken to be equivalent to the grade measured in the faces by means of chip sampling. The tonnage mined from the stopes is determined from survey volumetric measurements. Estimates of shaft head grade and tons include the grades and tons of waste, development ore, sweepings from old areas, and other sources, not all of which are sampled. The tonnage of ore delivered at the shaft is often estimated using skip factors. These factors are subject ...

  3. The presentation of leaching and bio-leaching from different ores using SIMPLEX EVOP

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeova, Mirjana; Gocev, Zivko

    2013-01-01

    The refractory or low grade lead/zinc domestic ores in Republic of Macedonia are investigated by conventional separation technology or flotation separation. In the mean time, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer program Multisimplex performances are appropriate and most acceptable and exce...

  4. The Relationship of Mental Pressure with Optimism and Academic Achievement Motivation among Second Grade Male High School Students

    Science.gov (United States)

    Sarouni, Ali Sedigh; Jenaabadi, Hossein; Pourghaz, Abdulwahab

    2016-01-01

    The present study aimed to examine the relationship of mental pressure with optimism and academic achievement motivation among second grade second period male high school students. This study followed a descriptive-correlational method. The sample included 200 second grade second period male high school students in Sooran. Data collection tools in…

  5. The Effect of Conceptual Change Approach to Eliminate 9th Grade High School Students' Misconceptions about Air Pressure

    Science.gov (United States)

    Akbas, Yavuz; Gencturk, Ebru

    2011-01-01

    The aim of this study was to determine the effectiveness of teaching based on conceptual change overcome misconceptions of 9th grade high school students about the subject of air pressure. The sampling of the study was formed with two classes of 9th grade students from a general high school in the city-center of Trabzon. A quasi-experimental…

  6. Low grade papillary transitional cell carcinoma pelvic recurrence masquerading as high grade invasive carcinoma, ten years after radical cystectomy

    Directory of Open Access Journals (Sweden)

    Mortazavi Amir

    2008-09-01

    Full Text Available Abstract Background Tumor recurrence following radical cystectomy for a low-grade superficial transitional cell carcinoma (TCC is exceedingly uncommon and has not been reported previously. Case presentation We describe a case of a young male presenting with anorexia, weight loss and a large, painful locally destructive pelvic recurrence, ten years after radical cystoprostatectomy. The pathology was consistent with a low-grade urothelial carcinoma. After an unsuccessful treatment with cisplatin-based chemotherapy, the patient underwent a curative intent hemipelvectomy with complete excision of tumor and is disease free at one year follow-up. Conclusion A literature review related to this unusual presentation is reported and a surgical solutions over chemotherapy and radiotherapy is proposed.

  7. Histochemical and ultrastructural study of an elastofibroma dorsi coexisting with a high grade spindle cell sarcoma

    Directory of Open Access Journals (Sweden)

    M Alberghini

    2009-06-01

    Full Text Available Elastofibroma dorsi is a pseudotumoral fibroproliferative lesion characterized by polymorphic fiber-like deposits of elastinophilic material. Several theories have been reported explaining the pathogenesis of elastofibroma. Recent cytogenetic studies have demonstrated chromosomal instability in elastofibromas, not normally observed in non-neoplastic tissues. These chromosomal defects are commonly observed in aggressive fibromatosis too. Such clinical observations suggest a multistage pathogenetic mechanism for the onset of elastofibroma. This study, using histochemical, immunohistochemical staining techniques, and ultrastructural examination, describes the detection of an otherwise typical elastofibroma contextual to a high grade sarcoma. Hence, the coexistence of elastofibroma and high-grade sarcoma may suggest a causal link between the two pathological entities. The results obtained suggest that the coexistence of the two pathological entities is conceivably coincidental.

  8. Immunotherapy for high-grade glioma: how to go beyond Phase I/II clinical trials.

    Science.gov (United States)

    van Gool, Stefaan

    2013-10-01

    Evaluation of: Lasky JL 3rd, Panosyan EH, Plant A et al. Autologous tumor lysate-pulsed dendritic cell immunotherapy for pediatric patients with newly diagnosed or recurrent high-grade gliomas. Anticancer Res. 33, 2047-2056 (2013). Immunotherapy for children and adults with high-grade glioma (HGG) is an emerging innovative treatment approach, which aims at stimulating the body's own immune system against HGG by using autologous dendritic cells pulsed with autologous tumor lysate as a therapeutic vaccine. This is the third report on immunotherapy for HGG in children, bringing additional knowledge and experience to the scientific community. However, at the same time, this and other manuscripts urge for the next step in treatment development.

  9. Complementary therapy use and quality of life in persons with high-grade gliomas.

    Science.gov (United States)

    Fox, Sherry; Laws, Edward R; Anderson, Frederick; Farace, Elana

    2006-08-01

    Studies have indicated that 30%-80% of cancer patients use complementary and alternative practices and products (CAPPs), but little is known about CAPPs use by persons with brain tumors. This secondary analysis of Glioma Outcomes Project data compared CAPPs users with nonusers, compared those who stopped using CAPPs with those who continued use, described frequency and patterns of CAPPs use, and compared the relationship of CAPPs use to self-reported quality of life (QOL) over time, in 186 persons with high-grade gliomas. CAPPs users at all three measurement points rated QOL higher, although not significantly higher, than nonusers. Study findings support further exploration of CAPPs use and its effects on key outcomes in persons with high-grade gliomas.

  10. Variation of Mechanical Properties of High RRR And Reactor Grade Niobium With Heat Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ganapati Myneni; H. Umezawa

    2003-06-01

    Superconducting rf cavities used as accelerating structures in particle accelerators are made from high purity niobium with residual resistance ratios greater than 250. Reactor grade niobium is also used to make wave-guide and/or end group components for these accelerating structures. The major impurities in this type of niobium are interstitially dissolved gases such as hydrogen, nitrogen, and oxygen in addition to carbon. After fabricating the niobium accelerating structures, they are subjected to heat treatments for several hours in vacuum at temperatures of up to 900 C for degassing hydrogen or up to 1400 C for improving the thermal conductivity of niobium considerably. These heat treatments are affecting the mechanical properties of niobium drastically. In this paper the variation of the mechanical properties of high purity and reactor grade niobium with heat treatments in a vacuum of {approx} 10{sup -6} Torr and temperatures from 600 C to 1250 C for periods of 10 to 6 hours are presented.

  11. Bevacizumab in High Grade Gliomas: A Case Report and Review of the Literature

    International Nuclear Information System (INIS)

    Balana, Carme; Cardona, Andres Felipe

    2007-01-01

    Patients with anaplastic astrocytoma or glioblastoma generally have adverse prognosis. Currently, standard treatment for high grade glial cell tumors consists of the concomitant use of radiotherapy and Themozolamide, followed by six months with the alkilant. However, subjects diagnosed with novo or recurrent tumors have overall survival rates from 3 to 15 months. Multiple chemotherapeutic and biological agents have been used to control progression, with no improvement in survival rates. New medication is being developed aimed at molecular targets such as the endothelial growth factor which can be regulated by, among others, Bevacizumab (BEV). Recent results from phase 11 trials combining BEV and Irinotecan (CPT-11) in patients with high grade gliomas revealed improved response rates, as well as disease free and overall survival rates. The case of a female with recurrent glioblastoma who achieved complete response after initiating BEV/CPT- 11 is presented

  12. Flotation of uranium from uranium ores in Canada. Part 1

    International Nuclear Information System (INIS)

    Muthuswami, S.V.; Vigayan, S.; Woods, D.R.; Banerjee, S.

    1983-01-01

    About 150 flotation tests were done on Elliot Lake ore with 15 reagents as collectors in order to screen and choose an attractive collector for uranium flotation. Several variables were studied including pH, conditioning time and mode of collector addition. The tests were done in a Denver or Agitair subaeration cell. The particle size of the ore was kept at 85% below -325 mesh. Three reagents (Kelex 00, TOPO, and cupferron) were identified as having the most promise. The best results were obtained with cupferron, where 93-95% of the uranium was recovered in 25-30% of the mass of original ore. Radium in the tails varied between 5 and 30 pCi/g depending on the mass of uranium floated. Radium was recovered in proportion to uranium in the tests done at neutral pH. The preconcentration results obtained by flotation alone were comparable to those obtained using pyrite flotation and wet high-intensity magnetic separation of uranium. The consumption of cupferron was 4 kg/Mg ore for each flotation stage. This was 10-15 times larger than the collector usage in conventional oxide flotation. This scheme did not require other reagents as depressants, activators or modifiers. Reproducibility was good and similar recoveries were obtained with fresh or old ores, and with distilled or mine water. The selectivity of cupferron for uranium in the ore studied was outstanding

  13. Uranium and thorium recovery in thorianite ore-preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

    2011-07-01

    This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

  14. Potential for cobalt recovery from lateritic ores in Europe

    Science.gov (United States)

    Herrington, R.

    2012-04-01

    Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

  15. Aerobic Glycolysis as a Marker of Tumor Aggressiveness: Preliminary Data in High Grade Human Brain Tumors

    Directory of Open Access Journals (Sweden)

    Andrei G. Vlassenko

    2015-01-01

    Full Text Available Objectives. Glucose metabolism outside of oxidative phosphorylation, or aerobic glycolysis (AG, is a hallmark of active cancer cells that is not directly measured with standard 18F-fluorodeoxyglucose (FDG positron emission tomography (PET. In this study, we characterized tumor regions with elevated AG defined based on PET measurements of glucose and oxygen metabolism. Methods. Fourteen individuals with high-grade brain tumors underwent structural MR scans and PET measurements of cerebral blood flow (CBF, oxygen (CMRO2 and glucose (CMRGlu metabolism, and AG, using 15O-labeled CO, O2 and H2O, and FDG, and were compared to a normative cohort of 20 age-matched individuals. Results. Elevated AG was observed in most high-grade brain tumors and it was associated with decreased CMRO2 and CBF, but not with significant changes in CMRGlu. Elevated AG was a dramatic and early sign of tumor growth associated with decreased survival. AG changes associated with tumor growth were differentiated from the effects of nonneoplastic processes such as epileptic seizures. Conclusions. Our findings demonstrate that high-grade brain tumors exhibit elevated AG as a marker of tumor growth and aggressiveness. AG may detect areas of active tumor growth that are not evident on conventional FDG PET.

  16. High maneuverability guidewire with functionally graded properties using new superelastic alloys.

    Science.gov (United States)

    Sutou, Y; Yamauchi, K; Suzuki, M; Furukawa, A; Omori, T; Takagi, T; Kainuma, R; Nishida, M; Ishida, K

    2006-01-01

    Nitinol shape memory alloys (SMAs) are attracting considerable attention as core materials for medical guidewires because of their excellent flexibility and shape retention. However, since Nitinol guidewires possess low rigidity, the pushability and torquability of the guidewires are insufficient. On the other hand, although guidewires made of stainless steel have high pushability, plastic deformation occurs easily. We have developed a new class of superelastic guidewires with functionally graded properties from the tip to the end by using new SMA core materials such as Cu-Al-Mn-based or Ni-free Ti-Mo-Sn SMAs. The tip portion of the guidewire shows excellent superelasticity (SE), while the body portion possesses high rigidity. These functionally graded characteristics can be realized by microstructural control. These guidewires with functionally graded properties show excellent pushability and torquability and are considerably easier to handle than conventional guidewires with Nitinol or stainless steel cores. Moreover, a metallic catheter using a Ni-free Ti-based SMA with high biocompatibility is introduced.

  17. Radiometric enrichment of nonradioactive ores

    International Nuclear Information System (INIS)

    Mokrousov, V.A.; Lileev, V.A.

    1979-01-01

    Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

  18. Hydrogeochemical radioactive features and prospecting in granopegmatite type uranium ore district in Danfeng area

    International Nuclear Information System (INIS)

    Feng Zhangsheng

    2011-01-01

    Hydrochemical radioactive prospecting plays an important role in the all stages of grano-pegmatite type uranium deposit exploration in Danfeng area dut to its fast, simple, economic and high effective advantage. Radioactive anomalous halo in the shallow underground water has identical distribution scopes with the ore-bearing biotite granite-pegmatite, which can be used to delineate uranium ore-forming prospective area, reconnaissance area and detailed prospecting area. Deep underground water close to the ore is characterized by hydrogeochemical radioactive features with high uranium and radon content. Through prospecting engineering of radioactive hydrogeochemical, the situation of blind ore bodies can be used to guide the layout. (authors)

  19. Floatability study of graphite ore from southeast Sulawesi (Indonesia)

    Science.gov (United States)

    Florena, Fenfen Fenda; Syarifuddin, Fahmi; Hanam, Eko Sulistio; Trisko, Nici; Kustiyanto, Eko; Enilisiana, Rianto, Anton; Arinton, Ghenadi

    2016-02-01

    Graphite ore obtained from Kolaka Regency, South East Sulawesi, Indonesia have been succesfully investigated for beneficiation by froth flotation technique. Preliminary study have been done to determine the minerals types, fixed carbon content and liberation size of the graphite. Graphite is naturally floatable due to its hydrophobic property. Some suitable reagents are usually added to increase effectiveness of recovery. In this article, enrichment of graphite by froth flotation was studied by investigating the effect of reagents concentrations, rotation speed and particle size on the carbon grade and recovery of the concentrate. The carbon grade increased from 3.00% to 60.00% at the optimum flotation conditions.

  20. Associations between circulating carotenoids, genomic instability and the risk of high-grade prostate cancer.

    Science.gov (United States)

    Nordström, Tobias; Van Blarigan, Erin L; Ngo, Vy; Roy, Ritu; Weinberg, Vivian; Song, Xiaoling; Simko, Jeffry; Carroll, Peter R; Chan, June M; Paris, Pamela L

    2016-03-01

    Carotenoids are a class of nutrients with antioxidant properties that have been purported to protect against cancer. However, the reported associations between carotenoids and prostate cancer have been heterogeneous and lacking data on interactions with nucleotide sequence variations and genomic biomarkers. To examine the associations between carotenoid levels and the risk of high-grade prostate cancer, also considering antioxidant-related genes and tumor instability. We measured plasma levels of carotenoids and genotyped 20 single nucleotide polymorphisms (SNP) in SOD1, SOD2, SOD3, XRCC1, and OGG1 among 559 men with non-metastatic prostate cancer undergoing radical prostatectomy. We performed copy number analysis in a subset of these men (n = 67) to study tumor instability assessed as Fraction of the Genome Altered (FGA). We examined associations between carotenoids, genotypes, tumor instability and risk of high-grade prostate cancer (Gleason grade ≥ 4 + 3) using logistic and linear regression. Circulating carotenoid levels were inversely associated with the risk of high-grade prostate cancer; odds ratios (OR) and 95% confidence intervals (CI) comparing highest versus lowest quartiles were: 0.34 (95% CI: 0.18-0.66) for α-carotene, 0.31 (95% CI: 0.15-0.63) for β-carotene, 0.55 (0.28-1.08) for lycopene and 0.37 (0.18-0.75) for total carotenoids. SNPs rs25489 in XRCC1, rs699473 in SOD3 and rs1052133 in OGG1 modified these associations for α-carotene, β-carotene and lycopene, respectively (P ≤ 0.05). The proportion of men with a high degree of FGA increased with Gleason Score (P carotenoids at diagnosis, particularly among men carrying specific somatic variations, were inversely associated with risk of high-grade prostate cancer. In exploratory analyses, higher lycopene level was associated with less genomic instability among men with low-grade disease which is novel and supports the hypothesis that lycopene may inhibit progression of

  1. Review of high thickness welding analysis using SYSWELD for a fusion grade reactor

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Ravi, E-mail: prakash@ipr.res.in; Gangradey, Ranjana, E-mail: ranjana@ipr.res.in

    2013-10-15

    Vacuum vessel and Cryostat for a fusion grade machine are massive structures involving fabrication of chambers with high thickness, about thickness up to 60 mm or more, made of special grade steels. Such machines require accurate planning of welding as the distortions and tolerance levels are stringent. Vacuum vessel of ITER has “D” shaped profile and is toroidal double walled huge steel cage of about 6 m width and 19 m diameter, and the Cryostat of 30 m height and width. The huge vacuum chamber will be fabricated in various parts/sectors due to huge size and then welded with countless weld joints to give the final components. High thickness welding of vacuum vessel is considered to be one of the most important elements in building a reactor of fusion grade due to large ineluctable distortions of welded parts after welding process as it is not easy to correct the large deformations after the welding process and finally the corrections are very expensive. The present paper demonstrates results of welding simulation done using SYSWELD software. Simulation results are of review studies of identified welding process like MIG, MAG, NG-TIG, TIG and EBW for welding large structural D shaped vacuum vessel profile as a case study. Simulation has carried out for SS316LN in clamped as well as unclamped condition for a distortion tolerance of ±2 mm with various weld factors and the local–global approach.

  2. Utility of intraoperative diagnostic C-arm angiography for management of high grade subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Zhikui Wei

    2015-06-01

    Full Text Available The accurate and efficient localization of underlying vascular lesions is crucial for prompt and definitive treatment of subarachnoid hemorrhage (SAH. To demonstrate the utility and feasibility of intraoperative C-arm angiography in cerebrovascular emergencies, we report five cases of high grade SAH and/or intracerebral hemorrhage (ICH where intraoperative diagnostic C-arm angiography was safely and effectively utilized. Initial evaluations of all patients included a non-contrast head CT scan, which was followed by urgent decompressive hemicraniectomy as a life-saving measure in the presence of markedly elevated intracranial pressure. Further diagnostic evaluations were performed intraoperatively using a multi-purpose C-arm angiography system. The C-arm angiography findings greatly aided the intraoperative planning and led to definitive treatments in four cases of SAH by elucidating the underlying neurovascular lesions. With this treatment strategy, two of the patients made moderately good recoveries from their SAH and/or ICH with a Glasgow outcome score (GOS of 4. Three of the patients expired despite maximal therapy mostly due to unfavorable presenting grade. These results suggest that C-arm angiography is a reasonable diagnostic and surgical planning tool for selected patients with high grade diffuse SAH who require immediate decompression.

  3. Review of high thickness welding analysis using SYSWELD for a fusion grade reactor

    International Nuclear Information System (INIS)

    Prakash, Ravi; Gangradey, Ranjana

    2013-01-01

    Vacuum vessel and Cryostat for a fusion grade machine are massive structures involving fabrication of chambers with high thickness, about thickness up to 60 mm or more, made of special grade steels. Such machines require accurate planning of welding as the distortions and tolerance levels are stringent. Vacuum vessel of ITER has “D” shaped profile and is toroidal double walled huge steel cage of about 6 m width and 19 m diameter, and the Cryostat of 30 m height and width. The huge vacuum chamber will be fabricated in various parts/sectors due to huge size and then welded with countless weld joints to give the final components. High thickness welding of vacuum vessel is considered to be one of the most important elements in building a reactor of fusion grade due to large ineluctable distortions of welded parts after welding process as it is not easy to correct the large deformations after the welding process and finally the corrections are very expensive. The present paper demonstrates results of welding simulation done using SYSWELD software. Simulation results are of review studies of identified welding process like MIG, MAG, NG-TIG, TIG and EBW for welding large structural D shaped vacuum vessel profile as a case study. Simulation has carried out for SS316LN in clamped as well as unclamped condition for a distortion tolerance of ±2 mm with various weld factors and the local–global approach

  4. Effect of smoking on high-grade cervical cancer in women on the basis of human papillomavirus infection studies

    Directory of Open Access Journals (Sweden)

    Jian-Hong Fang

    2018-01-01

    Conclusion: We concluded here that smoking leads to an enhanced risk of high-grade cervical lesions in persistent high-risk HPV-infected women. This makes a good understanding of smoking's role in cervical cancer.

  5. Fatigue of Austempered Ductile Iron with Two Strength Grades in Very High Cycle Regime

    Science.gov (United States)

    Zhang, Jiwang; Li, Wei; Song, Qingpeng; Zhang, Ning; Lu, Liantao

    2016-03-01

    In this study, Austempered ductile irons (ADIs) with two different strength grades were produced and the fatigue properties were measured at 109 cycles. The results show that the S-N curves give a typical step-wise shape and there is no fatigue limit in the very high cycle fatigue regime. The two grades ADI have the similar fracture behaviors and fatigue failure can initiate from defects at specimen surface and subsurface zone. On the fracture surfaces of some specimens, the `granular-bright-facet' area with rich carbon distribution is observed in the vicinity of the defect. The microstructure affects the crack behaviors at the early propagation stage. The ADI with upper and lower bainite shows higher fatigue strength compared with the ADI with coarse upper bainite.

  6. Origin of ores of endogeneous uranium ore deposits

    International Nuclear Information System (INIS)

    Kasanskij, V.I.; Laverov, N.P.; Tugarinov, A.I.

    1976-01-01

    The consideration mainly includes those endogenous uranium ore deposits of which more exact data are available, such as precambrian ones in areas of proto-activated old platforms, deposits of palaeozoic fold areas, and mesozoic deposits in areas of tectonic-magnetic activation. Their genesis and typical characters are mentioned and conclusions on the general distribution of the deposits are drawn. (author)

  7. Advances and Opportunities in Ore Mineralogy

    Directory of Open Access Journals (Sweden)

    Nigel J. Cook

    2017-11-01

    Full Text Available The study of ore minerals is rapidly transforming due to an explosion of new micro- and nano-analytical technologies. These advanced microbeam techniques can expose the physical and chemical character of ore minerals at ever-better spatial resolution and analytical precision. The insights that can be obtained from ten of today’s most important, or emerging, techniques and methodologies are reviewed: laser-ablation inductively-coupled plasma mass spectrometry; focussed ion beam-scanning electron microscopy; high-angle annular dark field scanning transmission electron microscopy; electron back-scatter diffraction; synchrotron X-ray fluorescence mapping; automated mineral analysis (Quantitative Evaluation of Mineralogy via Scanning Electron Microscopy and Mineral Liberation Analysis; nanoscale secondary ion mass spectrometry; atom probe tomography; radioisotope geochronology using ore minerals; and, non-traditional stable isotopes. Many of these technical advances cut across conceptual boundaries between mineralogy and geochemistry and require an in-depth knowledge of the material that is being analysed. These technological advances are accompanied by changing approaches to ore mineralogy: the increased focus on trace element distributions; the challenges offered by nanoscale characterisation; and the recognition of the critical petrogenetic information in gangue minerals, and, thus the need to for a holistic approach to the characterization of mineral assemblages. Using original examples, with an emphasis on iron oxide-copper-gold deposits, we show how increased analytical capabilities, particularly imaging and chemical mapping at the nanoscale, offer the potential to resolve outstanding questions in ore mineralogy. Broad regional or deposit-scale genetic models can be validated or refuted by careful analysis at the smallest scales of observation. As the volume of information at different scales of observation expands, the level of complexity

  8. The recovery of gold from refractory ores by the use of carbon-in-chlorine leaching

    Science.gov (United States)

    Greaves, John N.; Palmer, Glenn R.; White, William W.

    1990-09-01

    Recently, the U.S. Bureau of Mines examined the recovery of gold by chlorination of refractory carbonaceous and sulfidic ores, comparing various treatment methods in which a ground ore pulp is contacted with chlorine gas and activated carbon is added to the pulp for a carbon-in-chlorine leach (CICL). The objective of this research was to demonstrate the basic feasibility of CICL technology. Results showed that the organic carbon deactivating environment of CICL lowers, but does not eliminate, the adsorption of gold on activated carbon. In this environment, the refractory ore is altered, and gold is extracted and then recovered on activated carbon. With highly carbonaceous ores, CICL achieved a higher recovery than with primarily sulfidic refractory ores. Basic cyanide amenability testing of two carbonaceous ores achieved recoveries of only 5.5% and 46%. With CICL treatment, recoveries on carbon were 90% and 92%.

  9. NAGC Pre-K-Grade 12 Gifted Education Programming Standards: A Guide to Planning and Implementing High-Quality Services

    Science.gov (United States)

    Johnsen, Susan K., Ed.

    2012-01-01

    The new Pre-K-Grade 12 Gifted Education Programming Standards should be part of every school district's repertoire of standards to ensure that the learning needs of advanced students are being met. "NAGC Pre-K-Grade 12 Gifted Education Programming Standards: A Guide to Planning and Implementing High-Quality Services" details six standards that…

  10. Amphiboles and their host rocks in the high-grade metamorphic Precambrin of Rogaland/Vest-Agder, Sw. Norway

    NARCIS (Netherlands)

    Dekker, A.G.C.

    1978-01-01

    In the high-grade metamorphic Precambrian of the Sirdal-¢rsdal area, Rogaland/Vest-Agder,south-west Norway, the Ca-amphiboles show a change in pleochroic colours, not only with changes in metamorphic grade, but also to some extend in bulk composition. A regional study was performed on the

  11. Amphiboles and their host rocks in the high-grade metamorphic Precambrin of Rogaland/Vest-Agder, Sw. Norway

    NARCIS (Netherlands)

    Dekker, A.G.C.

    1978-01-01

    In the high-grade metamorphic Precambrian of the Sirdal-¢rsdal area, Rogaland/Vest-Agder,south-west Norway, the Ca-amphiboles show a change in pleochroic colours, not only with changes in metamorphic grade, but also to some extend in bulk composition. A regional study was performed on the amphiboles

  12. Grade Level Differences in High School Students' Conceptions of and Motives for Learning Science

    Science.gov (United States)

    Wang, Ya-Ling; Tsai, Chin-Chung

    2017-08-01

    Students' conceptions of learning science and their relations with motive for learning may vary as the education level increases. This study aimed to compare the quantitative patterns in students' conceptions of learning science (COLS) and motives for learning science (MLS) across grade levels by adopting two survey instruments. A total of 768 high school students were surveyed in Taiwan, including 204 eighth graders, 262 tenth graders, and 302 12th graders. In the current research, memorizing, testing, and calculating and practicing were categorized as reproductive conceptions of learning science, while increase of knowledge, applying, understanding and seeing-in-a-new-way were regarded as constructivist conceptions. The results of multivariate analyses of variance (MANOVA) revealed that conceptions of learning science are more constructivist as education level increases. Both tenth graders and 12th graders endorsed understanding, seeing-in-a-new-way, and the constructivist COLS composite more strongly than the eighth graders did. In addition, the results of multigroup structural equation modeling (SEM) analysis indicated that the positive relations between testing and reproductive COLS were stronger as the grade level increased, while the negative relations between reproductive COLS and deep motive were tighter with the increase in grade level.

  13. Antibody-guided three-step therapy for high grade glioma with yttrium-90 biotin

    International Nuclear Information System (INIS)

    Paganelli, G.; Grana, C.; Chinol, M.; Cremonesi, M.; De Cicco, C.; Zoboli, S.; De Braud, F.; Robertson, C.; Zurrida, S.; Veronesi, U.; Casadio, C.; Siccardi, A.G.

    1999-01-01

    While the incidence of brain tumours seems to be increasing, median survival in patients with glioblastoma remains less than 1 year, despite improved diagnostic imaging and neurosurgical techniques, and innovations in treatment. We have developed an avidin-biotin pre-targeting approach for delivering therapeutic radionuclides to gliomas, using anti-tenascin monoclonal antibodies, which seems potentially effective for treating these tumours. We treated 48 eligible patients with histologically confirmed grade III or IV glioma and documented residual disease or recurrence after conventional treatment. Three-step radionuclide therapy was performed by intravenous administration of 35 mg/m 2 of biotinylated anti-tenascin monoclonal antibody (1st step), followed 36 h later by 30 mg of avidin and 50 mg of streptavidin (2nd step), and 18-24 h later by 1-2 mg of yttrium-90-labelled biotin (3rd step). 90 Y doses of 2.22-2.96 GBq/m 2 were administered; maximum tolerated dose (MTD) was determined at 2.96 GBq/m 2 . Tumour mass reduction (>25%-100%), documented by computed tomography or magnetic resonance imaging, occurred in 12/48 patients (25%), with 8/48 having a duration of response of at least 12 months. At present, 12 patients are still in remission, comprising four with a complete response, two with a parital response, two with a minor response and four with stable disease. Median survival from 90 Y treatment is 11 months for grade IV glioblastoma and 19 months for grade III anaplastic gliomas. Avidin-biotin based three-step radionuclide therapy is well tolerated at the dose of 2.2 GBq/m 2 , allowing the injection of 90 Y-biotin without bone marrow transplantation. This new approach interferes with the progression of high-grade glioma and may produce tumour regression in patients no longer responsive to other therapies. (orig.)

  14. An investigation on high temperature fatigue properties of tempered nuclear-grade deposited weld metals

    Science.gov (United States)

    Cao, X. Y.; Zhu, P.; Yong, Q.; Liu, T. G.; Lu, Y. H.; Zhao, J. C.; Jiang, Y.; Shoji, T.

    2018-02-01

    Effect of tempering on low cycle fatigue (LCF) behaviors of nuclear-grade deposited weld metal was investigated, and The LCF tests were performed at 350 °C with strain amplitudes ranging from 0.2% to 0.6%. The results showed that at a low strain amplitude, deposited weld metal tempered for 1 h had a high fatigue resistance due to high yield strength, while at a high strain amplitude, the one tempered for 24 h had a superior fatigue resistance due to high ductility. Deposited weld metal tempered for 1 h exhibited cyclic hardening at the tested strain amplitudes. Deposited weld metal tempered for 24 h exhibited cyclic hardening at a low strain amplitude but cyclic softening at a high strain amplitude. Existence and decomposition of martensite-austenite (M-A) islands as well as dislocations activities contributed to fatigue property discrepancy among the two tempered deposited weld metal.

  15. Recurrence Patterns and Survival for Patients With Intermediate- and High-Grade Myxofibrosarcoma

    International Nuclear Information System (INIS)

    Haglund, Karl E.; Raut, Chandrajit P.; Nascimento, Alessandra F.; Wang, Qian; George, Suzanne; Baldini, Elizabeth H.

    2012-01-01

    Purpose: Myxofibrosarcoma (MFS) is a rare sarcoma with a predilection for multiple local recurrences (LR), for which optimal treatment has not been defined. We reviewed our experience to determine the impact of surgery and radiation therapy (RT) on pattern of recurrence, limb salvage, and overall survival (OS). Methods and Materials: Between 1995 and 2005, 36 patients with localized intermediate- or high-grade MFS were treated at our institution. Data on clinicopathologic features, treatments, and patient outcomes were reviewed and analyzed. Results: Median age was 72.5 years (range, 42–96 years). Median tumor size was 7.5 cm, and 34 tumors (94%) were high grade. All patients underwent surgery at our institution, including re-resections in 20 patients (56%) after initial surgery elsewhere. Margins were microscopically positive in 9 patients (25%). RT was given to 28 patients (78%) pre - and/or postoperatively. After a median follow-up of 3.5 years (range, 0.4–12.4 years), 11 patients (31%) developed LR. There were no significant predictors for LR on univariate analysis, including margin status or use of RT. Limb salvage was ultimately achieved in only 5 of 11 LRs (45%) because of multiple subsequent LRs. Distant recurrence (DR) occurred in 6 patients (17%). Median and 4-year OS were 96 months and 65%, respectively. Seven patients (19%) died of tumor-related causes, 6 of whom had DRs. On univariate analysis, tumor size was associated with OS. Conclusions: Despite aggressive surgery and RT, intermediate- and high-grade MFS are associated with a high rate of LR that adversely affects limb preservation. More aggressive local treatment strategies are necessary.

  16. Genetic Variants in TAP Are Associated with High-Grade Cervical Neoplasia

    Science.gov (United States)

    Einstein, Mark H.; Leanza, Suzanne; Chiu, Lydia G.; Schlecht, Nicolas F.; Goldberg, Gary L.; Steinberg, Bettie M.; Burk, Robert D.

    2018-01-01

    Purpose The transporter associated with antigen processing (TAP) is essential in assembling MHC-I proteins. Human papillomavirus (HPV) evades immune recognition by decreasing class I MHC cell surface expression through down-regulation of TAP1 levels. Consistent with heterogeneity in MHC expression is the individual variability in clearing detectable HPV infections. Genetic polymorphisms in TAP genes may affect protein structure, function, and the ability to clear HPV infection. Experimental Design Case-control study of women with cervical intraepithelial neoplasia (CIN) II or III (n = 114) and women without high-grade CIN (n = 366). Five nonsynonymous single nucleotide polymorphisms (SNP) in TAP1 and TAP2 were genotyped using DNA collected in cervicovaginal lavage samples using microsphere array technology (Luminex ×MAP). HPV typing was done using a PCR-based system with MY09/MY11 primers. TAP1 and TAP2 SNPs were validated by direct sequencing. Results Differences in allele distribution between women with high-grade cervical neoplasia and women without was seen for TAP1 I333V (P = 0.02) and TAP1 D637G (p = 0.01).The odds ratios (OR) for CIN III were significantly lower among carriers of the TAP1 I333V polymorphism (OR, 0.28; 95% confidence interval, 0.1-0.8), and TAP1 D637G polymorphism (OR, 0.27; 95% confidence interval, 0.1-0.7). These associations remained significant even after restricting the evaluation to women who were positive for high-risk HPV types. Conclusions In addition to the down-regulation of MHC-1 by oncogenic HPV, HPV pathogenesis might be facilitated by polymorphisms in the TAP proteins. Identifying TAP polymorphisms may potentially be used to identify women less susceptible to progression to high-grade CIN and cervical cancer. PMID:19188174

  17. Pion radiation for high grade astrocytoma: results of a randomized study

    International Nuclear Information System (INIS)

    Pickles, Tom; Goodman, George B.; Rheaume, Dorianne E.; Duncan, Graeme G.; Fryer, Chris J.; Bhimji, Shamim; Ludgate, Charles; Syndikus, Isabel; Graham, Peter; Dimitrov, Mario; Bowen, Julie

    1997-01-01

    Purpose: This study attempted to compare within a randomized study the outcome of pion radiation therapy vs. conventional photon irradiation for the treatment of high-grade astrocytomas. Methods and Materials: Eighty-four patients were randomized to pion therapy (33-34.5 Gyπ), or conventional photon irradiation (60 Gy). Entry criteria included astrocytoma (modified Kernohan high Grade 3 or Grade 4), age 18-70, Karnofsky performance status (KPS) ≥50, ability to start irradiation within 30 days of surgery, unifocal tumor, and treatment volume < 850 cc. The high-dose volume in both arms was computed tomography enhancement plus a 2-cm margin. The study was designed with the power to detect a twofold difference between arms. Results: Eighty-one eligible patients were equally balanced for all known prognostic variables. Pion patients started radiation 7 days earlier on average than photon patients, but other treatment-related variables did not differ. There were no significant differences for either early or late radiation toxicity between treatment arms. Actuarial survival analysis shows no differences in terms of time to local recurrence or overall survival where median survival was 10 months in both arms (p = 0.22). The physician-assessed KPS and patient-assessed quality of life (QOL) measurements were generally maintained within 10 percentage points until shortly before tumor recurrence. There was no apparent difference in the serial KPS or QOL scores between treatment arms. Conclusion: In contrast to high linear energy transfer (LET) therapy for central nervous system tumors, such as neutron or neon therapy, the safety of pion therapy, which is of intermediate LET, has been reaffirmed. However, this study has demonstrated no therapeutic gain for pion therapy of glioblastoma

  18. Synthesis and Characterization of High Aluminum Zeolite X from Technical Grade Materials

    Directory of Open Access Journals (Sweden)

    Seyed Kamal Masoudian

    2013-06-01

    Full Text Available Zeolites are widely used as ion exchangers, adsorbents, separation materials and catalyst due to their well-tailored and highly-reproducible structures; therefore, the synthesis of zeolite from low grade resources can be interested. In the present work, high aluminum zeolite X was prepared from mixing technical grade sodium aluminate and sodium silicate solutions at temperatures between 70°C and 100°C. The synthesized zeolite X was characterized by SEM and X-ray methods according to ASTM standard procedures. The results showed that aging of the synthesis medium at the room temperature considerably increased the selectivity of zeolite X formation. On the other hand, high temperature of reaction mixture during crystallization formed zeolite A in the product; therefore, it decreased the purity of zeolite X. In addition, it was found that increasing H2O/Na2O and decreasing Na2O/SiO2 molar ratios in the reaction mixture resulted product with higher purity. © 2013 BCREC UNDIP. All rights reservedReceived: 7th January 2013; Revised: 7th April 2013; Accepted: 19th April 2013[How to Cite: Masoudian, S. K., Sadighi, S., Abbasi, A. (2013. Synthesis and Characterization of High Alu-minum Zeolite X from Technical Grade Materials. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 54-60. (doi:10.9767/bcrec.8.1.4321.54-60][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4321.54-60] | View in  |

  19. Management and prognosis of patients with high-grade soft tissue sarcomas

    International Nuclear Information System (INIS)

    Alvegaard, T.A.

    1989-01-01

    Doxorubicin is one of the most active single agents in metastatic soft tissue sarcoma. This was the rationale for the evaluation og doxorubicin in an adjuvant situation for patients with high-grade soft tissue sarcoma in a randomized, Scandinavian, multicenter joint care program, which was carried out from January 1981 to February 1986, and included 240 patients. These patients comprised the base series for the investigations of the importance of the surgical margin and radiotherapy for local tumor control; the accuracy of malignancy grading and tumor typing; prognostic factors, including DNA content; and epidemiologic risk factors. The results showed that the use of doxorubicin as adjuvant chemotherapy did not have clinical benefit in patients with high-grade soft tissue sarcoma. The overall local tumor control was high (94 %) for radically operated on extremity-located tumors due to strict classification of surgical margins. The only risk factor for local recurrence was marginal surgery without radiotherapy with a four times higher risk than after compartmental or wide surgery. Twelve percent of the operations reported as radical were classified as marginal, demonstrating the importance of reevaluation of surgical margins, and in these patients the local recurrence rate was 37 %. The 5-year metastasis-free survival for the whole patients series was 55 %, with the extremes 79 % for the patients with no or only one risk factor and 0 % for those with four or five risk factors. The five prognostic factors found could be used for selection of high-risk patients for adjuvant chemotherapy in the future. The epidemiologic study gave limited support for an association between occupational phenoxy-acid exposure and soft tissue sarcoma development. (98 refs.)

  20. Comparison of T2 and FLAIR imaging for target delineation in high grade gliomas

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    Miller Robert W

    2010-01-01

    Full Text Available Abstract Background FLAIR and T2 weighted MRIs are used based on institutional preference to delineate high grade gliomas and surrounding edema for radiation treatment planning. Although these sequences have inherent physical differences there is limited data on the clinical and dosimetric impact of using either or both sequences. Methods 40 patients with high grade gliomas consecutively treated between 2002 and 2008 of which 32 had pretreatment MRIs with T1, T2 and FLAIR available for review were selected for this study. These MRIs were fused with the treatment planning CT. Normal structures, clinical tumor volume (CTV and planning tumor volume (PTV were then defined on the T2 and FLAIR sequences. A Venn diagram analysis was performed for each pair of tumor volumes as well as a fractional component analysis to assess the contribution of each sequence to the union volume. For each patient the tumor volumes were compared in terms of total volume in cubic centimeters as well as anatomic location using a discordance index. The overlap of the tumor volumes with critical structures was calculated as a measure of predicted toxicity. For patients with MRI documented failures, the tumor volumes obtained using the different sequences were compared with the recurrent gross tumor volume (rGTV. Results The FLAIR CTVs and PTVs were significantly larger than the T2 CTVs and PTVs (p Conclusions Although both T2 and FLAIR MRI sequences are used to define high grade glial neoplasm and surrounding edema, our results show that the volumes generated using these techniques are different and not interchangeable. These differences have bearing on the use of intensity modulated radiation therapy (IMRT and highly conformal treatment as well as on future clinical trials where the bias of using one technique over the other may influence the study outcome.

  1. High temperature deformation behavior, thermal stability and irradiation performance in Grade 92 steel

    Science.gov (United States)

    Alsagabi, Sultan

    The 9Cr-2W ferritic-martensitic steel (i.e. Grade 92 steel) possesses excellent mechanical and thermophysical properties; therefore, it has been considered to suit more challenging applications where high temperature strength and creep-rupture properties are required. The high temperature deformation mechanism was investigated through a set of tensile testing at elevated temperatures. Hence, the threshold stress concept was applied to elucidate the operating high temperature deformation mechanism. It was identified as the high temperature climb of edge dislocations due to the particle-dislocation interactions and the appropriate constitutive equation was developed. In addition, the microstructural evolution at room and elevated temperatures was investigated. For instance, the microstructural evolution under loading was more pronounced and carbide precipitation showed more coarsening tendency. The growth of these carbide precipitates, by removing W and Mo from matrix, significantly deteriorates the solid solution strengthening. The MX type carbonitrides exhibited better coarsening resistance. To better understand the thermal microstructural stability, long tempering schedules up to 1000 hours was conducted at 560, 660 and 760°C after normalizing the steel. Still, the coarsening rate of M23C 6 carbides was higher than the MX-type particles. Moreover, the Laves phase particles were detected after tempering the steel for long periods before they dissolve back into the matrix at high temperature (i.e. 720°C). The influence of the tempering temperature and time was studied for Grade 92 steel via Hollomon-Jaffe parameter. Finally, the irradiation performance of Grade 92 steel was evaluated to examine the feasibility of its eventual reactor use. To that end, Grade 92 steel was irradiated with iron (Fe2+) ions to 10, 50 and 100 dpa at 30 and 500°C. Overall, the irradiated samples showed some irradiation-induced hardening which was more noticeable at 30°C. Additionally

  2. Histogram analysis of diffusion kurtosis imaging derived maps may distinguish between low and high grade gliomas before surgery.

    Science.gov (United States)

    Qi, Xi-Xun; Shi, Da-Fa; Ren, Si-Xie; Zhang, Su-Ya; Li, Long; Li, Qing-Chang; Guan, Li-Ming

    2018-04-01

    To investigate the value of histogram analysis of diffusion kurtosis imaging (DKI) maps in the evaluation of glioma grading. A total of 39 glioma patients who underwent preoperative magnetic resonance imaging (MRI) were classified into low-grade (13 cases) and high-grade (26 cases) glioma groups. Parametric DKI maps were derived, and histogram metrics between low- and high-grade gliomas were analysed. The optimum diagnostic thresholds of the parameters, area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were achieved using a receiver operating characteristic (ROC). Significant differences were observed not only in 12 metrics of histogram DKI parameters (PHistogram analysis of DKI may be more effective in glioma grading.

  3. Investigation of 9th Grade High School Students’ Attitudes towards Science Course

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    Orhan Karamustafaoglu

    2017-12-01

    Full Text Available In this study, ninth grade students’ attitudes towards science were investigated in terms of self-regulation strategies, motivational beliefs and gender variables. The sample of this study includes 322 male and 296 female in total 618 students from 3 different high schools (Science high school, Anatolian high school, and Vocational high school in center district of Amasya city. To collect the data, the researchers employed “Motivated Strategies for Learning Questionnaire” which has been developed by Pintrich and De Groot in 1990, adapted into Turkish by Uredi in 2005 and consists of 44 items and “Colorado Learning Attitudes about Science Survey (CLASS” has been developed by Adams and others in 2006, adapted into Turkish by Bayar and Karamustafaoğlu in 2015 and consists of 36 items. For data analysis, mean, standard deviation, independent t-test and correlation were addressed. The results of this study show that there are statistically significant relationships between 9th grade students’ attitudes towards science and self-regulation strategies, motivational beliefs, and gender.

  4. Gender Gaps in High School GPA and ACT Scores: High School Grade Point Average and ACT Test Score by Subject and Gender. Information Brief 2014-12

    Science.gov (United States)

    ACT, Inc., 2014

    2014-01-01

    Female students who graduated from high school in 2013 averaged higher grades than their male counterparts in all subjects, but male graduates earned higher scores on the math and science sections of the ACT. This information brief looks at high school grade point average and ACT test score by subject and gender

  5. Silicic, high- to extremely high-grade ignimbrites and associated deposits from the Paraná Magmatic Province, southern Brazil

    Science.gov (United States)

    Luchetti, Ana Carolina F.; Nardy, Antonio J. R.; Madeira, José

    2018-04-01

    The Cretaceous trachydacites and dacites of Chapecó type (ATC) and dacites and rhyolites of Palmas type (ATP) make up 2.5% of the 800.000 km3 of volcanic pile in the Paraná Magmatic Province (PMP), emplaced at the onset of Gondwana breakup. Together they cover extensive areas in southern Brazil, overlapping volcanic sequences of tholeiitic basalts and andesites; occasional mafic units are also found within the silicic sequence. In the central region of the PMP silicic volcanism comprises porphyritic ATC-type, trachydacite high-grade ignimbrites (strongly welded) overlying aphyric ATP-type, rhyolite high- to extremely high-grade ignimbrites (strongly welded to lava-like). In the southwestern region strongly welded to lava-like high-grade ignimbrites overlie ATP lava domes, while in the southeast lava domes are found intercalated within the ignimbrite sequence. Characteristics of these ignimbrites are: widespread sheet-like deposits (tens to hundreds of km across); absence of basal breccias and basal fallout layers; ubiquitous horizontal to sub-horizontal sheet jointing; massive, structureless to horizontally banded-laminated rock bodies locally presenting flow folding; thoroughly homogeneous vitrophyres or with flow banding-lamination; phenocryst abundance presenting upward and lateral decrease; welded glass blobs in an 'eutaxitic'-like texture; negligible phenocryst breakage; vitroclastic texture locally preserved; scarcity of lithic fragments. These features, combined with high eruption temperatures (≥ 1000 °C), low water content (≤ 2%) and low viscosities (104-7 Pa s) suggest that the eruptions were characterized by low fountaining, little heat loss during collapse, and high mass fluxes producing extensive deposits.

  6. Co-Testing of Cervical Screening Tests in Detection of High Grade Cervical Intraepithelial Neoplasia

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    Smita Asthana

    2017-10-01

    Full Text Available Introduction: Co-testing performance for detection of high grade Cervical Intraepithelial Neoplasia (CIN has not been adequately addressed from Low Resource Countries (LRCs. Where isolated tests do not have adequate performance, further explorations are recommended. Aim: To evaluate the co-testing of conventional cervical screening tests such as Papanicolaou (Pap and Visual Inspection Cervix with Acetic Acid (VIA, with care HPV on Cervical Samples (CHPV or on Vaginal Samples (VHPV in the detection of high grade CIN. Materials and Methods: The cross-sectional study was conducted on ever married women of age 30 to 59 years in a rural community of Dadri. Women were screened by CHPV, VHPV, and Pap and VIA methods. Confirmation of screen positives was done by histology. Sensitivity, Specificity and likelihood ratios of different combinations of test determined to evaluate the performance. Results: Total eligible women, 66.2% (5032/7604 responded for screening. Analysis was performed on 4658, after excluding those who did not complete all screenings. Co-testing of CHPV (OR=246 or VHPV (OR=278 with Pap had highest association. Positive likelihood ratios of CHPV and VHPV with Pap in CIN II+ detection rates were 13.0 and 11.8 and in CIN III+ the detection rates were 18.0 and 16.0 respectively. Higher sensitivities and specificities were observed in co-testing for CIN III+ detection as against CIN II+ lesions. Conclusion: Choice of co-testing in a pair of tests for detection of high grade CIN is likely to depend on whether screening is targeted for developed or low resource country. VIA in isolation might not yield optimal results for LRCs.

  7. Role of combined circumareolar skin excision and liposuction in management of high grade gynaecomastia

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    Arindam Sarkar

    2014-01-01

    Full Text Available Introduction: High-grade gynaecomastia (Simon IIb and III has tissue excess (skin excess, enlarged areola, and displaced nipple, which is best managed surgically; however, results of conventional breast reduction surgeries and liposuction is not very good. Aim of our study was to describe a combined technique to manage these problems to produce a good result. Material and Method: This was a 2-year study among 12 patients of high grade gynaecomastia. Clinical and laboratory findings were normal. Pre-operatively in standing position, diameter of breast and areola, position of nipple, and amount of skin excess were marked. Under general anaesthesia, tumescent infiltration, circumareolar de-epithelisation of skin excess, and liposuction was completed. Redundant portion of the breast was sharply dissected and pulled out. Areola was fixed over pectoralis fascia at mid humerus level, just medial to the mid-clavicular line. Outer borders of the de-epithelised area were apposed by the purse-string effect of a subdermal suture, and further apposed by few half buried horizontal mattress sutures. Drains for 24 hour and compressive dressings for 6 weeks were used. Result: Mean age of presentation was 25.8 year; emotional discomfort was the chief complaint. Among 12 patients, 10 patients had bilateral gynaecomastia and 8 patients had enlarged and displaced nipple-areola complex. Average hospital stay was 2.41 days and recoveries were usually uneventful. Conclusion: The problem of tissue excess and tissue displacement in high grade gynaecomastia can be well managed by this combined circumareolar skin reduction and liposuction technique to achieve a scar-less flat male chest.

  8. Classification of high-grade spondylolistheses based on pelvic version and spine balance: possible rationale for reduction.

    Science.gov (United States)

    Hresko, Michael T; Labelle, Hubert; Roussouly, Pierre; Berthonnaud, Eric

    2007-09-15

    Retrospective review of a radiographic database of high-grade spondylolisthesis patients in comparison with asymptomatic controls. To analyze the sagittal spinopelvic alignment in high-grade spondylolisthesis patients and identify subgroups that may require reduction to restore sagittal balance. High-grade spondylolisthesis is associated with an abnormally high pelvic incidence (PI); however, the spatial orientation of the pelvis, determined by sacral slope (SS) and pelvic tilt (PT), is not known. We hypothesized that sagittal spinal alignment would vary with the pelvic orientation. Digitized sagittal radiographs of 133 high-grade spondylolisthesis patients (mean age, 17 years) were measured to determined sagittal alignment. K-means cluster analysis identified 2 groups based on the PT and SS, which were compared by paired t test. Comparisons were made to asymptomatic controls matched for PI. High-grade spondylolisthesis patients had a mean PI of 78.9 degrees +/- 12.1 degrees . Cluster analysis identified a retroverted, unbalanced pelvis group with high PT (36.5 degrees +/- 8.0 degrees )/low SS (40.3 degrees +/- 9.0 degrees ) and a balanced pelvic group with low PT (mean 21.3 degrees +/- 8.2 degrees )/high SS (59.9 degrees +/- 11.2 degrees ). The retroverted pelvis group had significantly greater L5 incidence and lumbosacral angle with less thoracic kyphosis than the balanced pelvic group. A total of 83% of controls had a "balanced pelvis" based on the categorization by SS and PT. Analysis of sagittal alignment of high-grade spondylolisthesis patients revealed distinct groups termed "balanced" and "unbalanced" pelvis. The PT and SS were similar in controls and balanced pelvis patients. Unbalanced pelvis patients had a sagittal spinal alignment that differed from the balanced pelvis and control groups. Treatment strategies for high-grade spondylolisthesis should reflect the different mechanical strain on the spinopelvic junction in each group; reduction techniques

  9. Diagnostic Values of DCE-MRI and DSC-MRI for Differentiation Between High-grade and Low-grade Gliomas: A Comprehensive Meta-analysis.

    Science.gov (United States)

    Liang, Jianye; Liu, Dexiang; Gao, Peng; Zhang, Dong; Chen, Hanwei; Shi, Changzheng; Luo, Liangping

    2018-03-01

    This study aimed to collect the studies on the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI) in differentiating the grades of gliomas, and evaluate the diagnostic performances of relevant quantitative parameters in glioma grading. We systematically searched studies on the diagnosis of gliomas with DCE-MRI or DSC-MRI in Medline, PubMed, China National Knowledge Infrastructure database, Cochrane Library, and Embase published between January 2005 and December 2016. Standardized mean differences and 95% confidence intervals were calculated for volume transfer coefficient (K trans ), volume fraction of extravascular extracellular space (V e ), rate constant of backflux (K ep ), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) using Review Manager 5.2 software. Sensitivity, specificity, area under the curve (AUC), and Begg test were calculated by Stata 12.0. Twenty-two studies with available outcome data were included in the analysis. The standardized mean difference of K trans values between high-grade glioma and low-grade glioma were 1.18 (0.91, 1.45); V e values were 1.43 (1.06, 1.80); K ep values were 0.65 (-0.05, 1.36); rCBV values were 1.44 (1.08, 1.81); and rCBF values were 1.17 (0.68, 1.67), respectively. The results were all significant statistically (P values (P = .07), and high-grade glioma had higher K trans , V e , rCBV, and rCBF values than low-grade glioma. AUC values of K trans , V e , rCBV, and rCBF were 0.90, 0.88, 0.93, and 0.73, respectively; rCBV had the largest AUC among the four parameters (P < .05). Both DCE-MRI and DSC-MRI are reliable techniques in differentiating the grades of gliomas, and rCBV was found to be the most sensitive one. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  10. Effects of Low-temperature Pre-oxidation on the Titanomagnetite Ore Structure and Reduction Behaviors in a Fluidized Bed

    Science.gov (United States)

    Adetoro, Ajala Adewole; Sun, Haoyan; He, Shengyi; Zhu, Qingshan; Li, Hongzhong

    2018-04-01

    With respect to high efficient utilization of low-grade iron ore resource, the behavior of low-temperature "973 K to 1123 K (700 °C to 850 °C)" oxidation, on the phase transition of SA TTM ore (South African titanomagnetite), and its effect on subsequent reduction was investigated. The results showed that hematite and rutile are the oxidation product below 1048 K (775 °C), while pseudobrookite is the stable phase above 1073 K (800 °C). With the increase in temperature and oxidation time, there is a competitive relationship between the amount of hematite and pseudobrookite generated. The reduction efficiency of SA TTM was significantly improved by oxidation pretreatment, primarily due to the dissociation of titania-ferrous oxides to more easily reducible hematite. But the generation of pseudobrookite phase decreases the amount of free hematite available for reduction, which weakens the improvement effect of pre-oxidation. The equilibrium relationship between the metallization degree and the gas reduction potential for TTM ore with pre-oxidation treatment has been built. Finally, the reduction metallization degree for the first and second step can be improved averagely by 16.67 and 3.45 pct, respectively, for sample pre-oxidized at 1098 K (825 °C) for 15 and 90 minutes, while 26.96 and 7.4 pct, improvement is achieved for sample pre-oxidized at a lower temperature of 1048 K (775 °C) for 120 minutes.

  11. Synthesis of Zeolite NaA from Low Grade (High Impurities) Indonesian Natural Zeolite

    OpenAIRE

    Mustain, Asalil; Wibawa, Gede; Nais, Mukhammad Furoiddun; Falah, Miftakhul

    2014-01-01

    The zeolite NaA has been successfully synthesized from the low grade natural zeolite with high impurities. The synthesis method was started by mixing natural zeolite powder with NH4Cl aqueous solution in the reactor as pretreatment. The use of pretreatment was to reduce the impurities contents in the zeolite. The process was followed by alkaline fusion hydrothermal treatment to modify the framework structure of natural zeolite and reduce the SiO2/Al2O3 ratio. Finally, the synthesized zeolite ...

  12. EG-01EPIGENETIC INACTIVATION OF ARGININE BIOSYNTHESIS PATHWAY IN PAEDIATRIC HIGH GRADE GLIOMA

    Science.gov (United States)

    Channathodiyil, Prasanna; Kardooni, Hoda; Khozoie, Combiz; Nelofer, Syed; Darling, John; Morris, Mark; Warr, Tracy

    2014-01-01

    Aberrant cellular metabolism contributes significantly to the growth and proliferation of several tumour types. Identification of genes that control critical metabolic pathways is a major factor in the development of novel therapies that target metabolic defects in tumour cells. Our aim is to identify such genes in paediatric high grade glioma that are altered due to promoter hyper-methylation of cytosine residues in CpG dinucleotides. Genome wide DNA methylation profiling using Illumina infinium methylation 450K bead chip array was performed on 18 well-characterised short term cultures derived from paediatric high grade astrocytoma including 3 from diffuse intrinsic pontine glioma. Data analyses were based on beta scores of probes for each gene as measures of intensities of methylation. Genes were selected with beta scores of tumour > =0.70 and that of normal human astrocytes < =0.30. We identified that two vital genes involved in the regulation of arginine biosynthetic pathway, argininosuccinate synthetase 1(ASS1) and argininosuccinate lyase (ASL) were methylated in 9/18 (50%) cases. Hyper methylation was confirmed by methylation-specific PCR and up-regulation of gene expression following treatment with 2 µM 5-aza-2'-deoxyctidine. Down-regulation of ASS1 in hyper methylated samples was confirmed by Western blot analysis. Our findings report epigenetic deregulation of ASS1 and ASL in a subset of paediatric high grade glioma. The enzymes encoded by these genes are essential elements of urea cycle that function together in the de novo synthesis of arginine from citrulline. Tumour cells with deficient ASS1/ASL depend on external sources of arginine for survival and have been reported to be sensitive to autophagic cell death induced by arginine starvation. Therefore, further investigation may render the possibility of arginine-deprivation therapy in such sub type of paediatric high grade glioma. This therapeutic approach is of interest as tumour cells with abnormal

  13. Reirradiation and lomustine in patients with relapsed high-grade gliomas

    International Nuclear Information System (INIS)

    Arcicasa, Mauro; Roncadin, Mario; Bidoli, Ettore; Dedkov, Anatolyi; Gigante, Marco; Trovo, Mauro G.

    1999-01-01

    Purpose: The aim of this study was to evaluate the toxicity, response, and survival of patients with relapsed high-grade gliomas after radiation therapy (RT) combined with lomustine (CCNU). Methods and Materials: Thirty-one patients with relapsed gliomas at least 6 months after completion of RT were reirradiated. Twenty-four patients had a pathological diagnosis of high-grade gliomas, whereas 7 had a radiological diagnosis of relapsed malignant gliomas. The study focused on patients with high-grade relapsed gliomas. A total dose of 34.5 Gy was delivered in 23 fractions over 4.5 weeks. Oral administration of CCNU (130 mg/m 2 ) was begun at the same time as RT, and was repeated every 6 weeks until disease progression, or up to 12 courses. Results: Twelve of 24 patients had surgery before RT plus CCNU treatment. Median interval between RT courses was 14 months (range 6-73). All patients received a complete course of RT, and 22 of 24 patients received at least one course of CCNU. Objective responses were seen in 14 evaluable patients: 3 with partial response, 5 with stable disease, and 6 with progressive disease. Duration of partial response was 20, 9, and 8 months. Median time to progression and overall survival from the onset of retreatment were 8.4 months (range 1-22) and 13.7 months (range 1-63+), respectively. One case of G4 thrombocytopenia was observed. Five patients had G1 or G2 leucopenia and 3 patients had G3 leucopenia. Moderate nausea and vomiting were reported in 4 patients. One patient, after one course of CCNU, refused further chemotherapy. No significant difference in survival from relapse was found between patients who underwent surgery before RT plus CCNU and those who received only RT plus CCNU (p = 0.74). Conclusion: Overall, the acute toxicity was moderate, and patient compliance was good. Reirradiation of high-grade glioma was associated with modest subjective and objective response rates. It is remarkable that median overall survival from relapse

  14. The Swedish infant high-grade reflux trial: UTI and renal damage.

    Science.gov (United States)

    Nordenström, Josefin; Sjöström, Sofia; Sillén, Ulla; Sixt, Rune; Brandström, Per

    2017-04-01

    High-grade vesicoureteral reflux (VUR) in children is associated with recurrent urinary tract infection (UTI) and renal damage. Breakthrough UTI despite continuous antibiotic prophylaxis (CAP) during the first years of life is a matter of concern and evokes early intervention. We investigated whether early endoscopic treatment (ET) of VUR grade 4-5 can reduce the risk of UTI recurrence and renal scarring. This prospective, randomized, controlled, multicentre, 1-year follow-up trial comprised 77 infants, UTIs were reported. There were 27 recurrent febrile UTIs in 6 (16%) children in the ET group and in 10 (26%) in the CAP group (p = 0.43), in eight (36%) girls and eight (15%) boys (p = 0.039). Successful VUR outcome (VUR 0-2) was seen in 22 (59%) in the ET and eight (21%) in the CAP group (p = 0.0014). Multiple recurrences were only seen in patients with persistent dilating reflux at follow-up (p = 0.019). Deterioration on scintigraphy was seen in eight children (9 kidneys) with no difference between treatment groups (p = 0.48) or sex (p = 0.17). Renal deterioration was associated with high bladder capacity (BC) and large residual volume (PVR) at 1 year (p = 0.0092 and p = 0.041). Six of the eight children with renal deterioration had a recurrent UTI (p = 0.0032). Seven of nine renal units with deterioration were seen in children with persistent VUR 3-5 at follow-up. Univariable logistic regression identified female sex and high PVR as positive predictors for recurrent UTI (p = 0.039 and 0.034) and high PVR tended to predict renal deterioration (p = 0.053). No differences between the treatment groups regarding recurrent UTI and renal deterioration could be found. Increased PVR and female sex were positive predictors for UTI recurrences. VUR grade at follow-up was correlated to UTI recurrence and renal deterioration. This study did not show any difference between ET and CAP in reducing the risk of UTI recurrence or renal deterioration. The rate

  15. Sinterization of manganese ore tailings under argon atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Valduga, M.M.F.; Lima, F.; Lima, R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2014-07-01

    Manganese is an element widely used in Metallurgy, however the Brazilian reserves has low grade. The aim of this work was to obtain and characterize the sinters from manganese ore tailings. The fines (less than 400⧣) were calcinated (800°C - 3600s) and homogenized with activated charcoal (7 and 10%) and CaO (5 and 10%). The sintering were carried out at 1135, 1140 and 1145°C during 7200 and 14400s under argon atmosphere. The sintered products were characterized by EDS analysis, BET surface area, apparent density, X-rays diffraction and SEM/EDS. The surface area was 0.03m2/g. The alkali element present (potassium) justified the low melting point of waste (1140°C). Due to the chemical complexity of the tailings, several phases were characterized in the products: pores, silicates with high content of manganese in the matrix, other silicates with different proportions of Al, Mn, Mg and Ca, pure Fe, SiO2, etc. (author)

  16. Assessment of the effect of innovation on the costs of a uranium ore concentration plant by means of a technical and economic model. Examples of applications: direct precipitation of the peroxide UO4 xH2O high temperature and high concentration alkaline treatment

    International Nuclear Information System (INIS)

    Boutonnet, G.; Roullier, J.P.

    1983-01-01

    Uranium Pechiney Ugine Kuhlmann has developed an economic model for uranium ore treatment plants. In this model, the basic economic data for a given plant, such as capital expenditures, operating costs, etc. are derived from parameters based partly on the size of the plant and the production progamme considered, and partly on the cost and specifications of the ore to be treated. In addition to numerous macro-economic applications (not considered here), the model can be used for making coherent comparisons of the economy of a plant designed for an innovative production process with that of the same plant designed for a conventional process of acid treatment followed by solvent extraction. The model shows that two new processes are highly competitive with the conventional process. They are: 1. Direct precipitation of the peroxide UO 4 xH 2 O in the pregnant liquor without concentration or purification by solvents or exchangers, and 2. High temperature and high concentration alkaline treatment

  17. Fe extraction from çayeli copper ores by bioleaching with eco freiendly acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Kocadagistan, M.E.; Bayhan, Y.K.

    2017-01-01

    Recently, biological treatment; an important recovery process, has became important from the environmental and economical respects in recovery of metallic values from low-grade sulfur-bearing ores or concentrates. Bacterial ore leaching can be applied to extract heavy metals from low grade ores, industrial wastes and other materials on an industrial scale by different procedures. The main objective of this work was to investigate the dissolution of Fe from Çayeli copper ores, via a bioleaching process using Acidithiobacillus ferrooxidans. Experiments performed with batch operation in jar test equipment were conducted at different pH values, pulp densities, inoculum volumes, particle sizes, stirring conditions and operation times. The optimal parameters were found as follows; at pH 2, the pulp density; 4% (w/v), inoculum volume; 4% (v/v), stirring rate; 120 rpm and particle size; -0.053 mm for 192nd and 288th hours, at pH 2, the pulp density; 4% (w/v), inoculum volume; 5% (v/v), stirring speed; 200 rpm and particle size; -0.053 mm for 384th and 480th hours. By performing the bioleaching process under these conditions, almost 99% of the iron extent in the ore was transfer from ore into solution, however the experiments in which distilled water was used instead of modified 9K*, only 18.5% Fe efficiency was obtained. (author)

  18. A Needs Analysis Approach to the Evaluation of Iranian Third-Grade High School English Textbook

    Directory of Open Access Journals (Sweden)

    Nasser Rashidi

    2014-09-01

    Full Text Available Needs analysis as an integral part of evaluative review of English materials, mainly textbooks, requires giving sufficient attention in all English language learning contexts. This issue seems to be more demanding in English as a Foreign Language (EFL contexts where the textbooks are the main sources of input for the learners. However, in some cases, this important factor is excluded entirely or at least limited to the ideas of major stakeholders. This article reports on the findings of a study conducted to evaluate an English textbook (the third-grade high school English book, which is being used in all state high schools in Iran by using a needs analysis framework. First, the needs analysis questionnaires were administered among 180 third-grade female high school students for whom the textbook was designed. Having investigated the students’ perceived foreign language needs, the researcher then used it as the basis for evaluating the textbook. The results of the textbook evaluation revealed that although all language skills and components were almost important for the majority of the students, the textbook could not fully support all of them together. Finally, it was suggested that the textbook be revised or at least supplemented by other instructional materials, so that it could be more effective for the aforementioned learners.

  19. Novel therapies for high-grade gliomas: A vision for future

    Directory of Open Access Journals (Sweden)

    Vivek Tandon

    2012-01-01

    Full Text Available The treatment for high-grade glioma remains an enigma. The standard treatment using surgery, radiation therapy and chemotherapy for such highly malignant lesions has only yielded modest results, in terms of survival and improving the quality of life of patients. Less than 10% of such patients survive beyond two years. All conventional therapies have failed to increase the survival beyond this extent. There has been a growing interest in the molecular approaches for the treatment of high-grade gliomas which include gene therapy, oncolytic virotherapy, and immunotherapy. These new therapies are in preclinical and investigational stages. They may not substitute the conventional therapies; they may not be the ultimate elixir for this deadly disease. However, in the coming years, they are likely to have synergistic and complimentary roles alongside conventional therapies. Through this paper, we have attempted to highlight the rationale behind gene therapy which can be used for cytotoxic approaches, immunomodulation strategy, and targeted toxin delivery in the tumor cell. We have reviewed current available literature and through this paper focus on reporting such therapeutic options, their potential usage, benefits and limitations.

  20. Dating of zircon from high-grade rocks: Which is the most reliable method?

    Directory of Open Access Journals (Sweden)

    Alfred Kröner

    2014-07-01

    Full Text Available Magmatic zircon in high-grade metamorphic rocks is often characterized by complex textures as revealed by cathodoluminenscence (CL that result from multiple episodes of recrystallization, overgrowth, Pb-loss and modifications through fluid-induced disturbances of the crystal structure and the original U-Th-Pb isotopic systematics. Many of these features can be recognized in 2-dimensional CL images, and isotopic analysis of such domains using a high resolution ion-microprobe with only shallow penetration of the zircon surface may be able to reconstruct much of the magmatic and complex post-magmatic history of such grains. In particular it is generally possible to find original magmatic domains yielding concordant ages. In contrast, destructive techniques such as LA-ICP-MS consume a large volume, leave a deep crater in the target grain, and often sample heterogeneous domains that are not visible and thus often yield discordant results which are difficult to interpret. We provide examples of complex magmatic zircon from a southern Indian granulite terrane where SHRIMP II and LA-ICP-MS analyses are compared. The SHRIMP data are shown to be more precise and reliable, and we caution against the use of LA-ICP-MS in deciphering the chronology of complex zircons from high-grade terranes.

  1. Management of wastes containing radioactivity from mining and milling of uranium ores in Northern Australia

    International Nuclear Information System (INIS)

    Costello, J.M.

    1977-01-01

    The procedures and controls to achieve safe management of wastes containing radioactivity during the mining and processing of uranium ores are mainly site specific depending on the nature, location and distribution of the ore and gangue material. Waste rock and below-ore-grade material containing low levels of radioactivity require disposal at the mine site. In open cut mining the material is generally stockpiled above ground, with revegetation and collection of run-off water. Some material may be used to backfill open cuts. Management of these wastes requires a thorough investigation of ground water hydrology and surface soil characteristics to control dissipation of radioactive material. Dust containing radon and radioactive particulate is produced during ore milling, and dusts of ore concentrate are generated during calcination and packaging of the yellowcake product. These dusts are managed by ventilation and filtration systems, working conditions, and discharges to atmosphere will be according to the Australian Code of Practice on Radiation Protection during Mining and Milling of Uranium Ores. The chemical waste stream from leaching and processing of the uranium ores contains the majority of the radioactivity resulting from radium and its decay products. Neutralised effluent is discharged into holding ponds for settling of solids. This paper describes the nature of wastes containing radioactivity resulting from the mining and milling of uranium, and illustrates modern engineering practices and monitoring procedures to manage the wastes, as described in the Environmental Impact statement produced by Ranger Uranium Mines Proprietary Limited for public hearings

  2. Management of wastes containing radioactivity from mining and milling uranium ores in Northern Australia

    International Nuclear Information System (INIS)

    Costello, J.M.

    1977-01-01

    The procedures and controls to achieve safe management of wastes containing radioactivity during the mining and processing of uranium ores are mainly site-specific depending on the nature, location and distribution of the ore and gangue material. Waste rock and below-ore-grade material containing low levels of radioactivity require disposal at the mine site. In open-cut mining the material is generally stockpiled above ground, with revegetation and collection of run-off water. Some material may be used to backfill open cuts. Management of these wastes requires a thorough investigation of groundwater hydrology and surface soil characteristics to control dissipation of radioactive material. Dust containing radon and radioactive particulate is produced during ore milling, and dusts of ore concentrate are generated during calcination and packaging of the yellowcake product. These dusts are managed by ventilation and filtration systems; working conditions and discharges to atmosphere will be according to the Australian Code of Practice on Radiation Protection during Mining and Milling of Uranium Ores. The chemical waste stream from leaching and processing of the uranium ores contains most of the radioactivity resulting from radium and its decay products. Neutralized effluent is discharged into holding ponds for settling solids. The paper describes the nature of wastes containing radioactivity resulting from the mining and milling of uranium, and illustrates modern engineering practices and monitoring procedures to manage the wastes, as described in the Environmental Impact Statement produced by Ranger Uranium Mines Pty Ltd (RUM) for public hearings. (author)

  3. Ore deposits and epithermal evidences associated with intra-magmatic faults at Aïn El Araâr-Oued Belif ring structure (NW of Tunisia)

    Science.gov (United States)

    Aissa, Wiem Ben; Aissa, Lassaâd Ben; Amara, Abdesslem Ben Haj; Tlig, Said; Alouani, Rabah

    2017-03-01

    Hydrothermal ore deposits at Aïn El Araâr-Oued Belif location are classified as epithermal deposits type. The ore bodies are hosted by upper Turonian (8-9 M.y) volcanic rhyodacitic complex. Polymetallic sulfide orebodies are mainly concentrated within intra-magmatic faults. Petrographic, XRD, and TEM-STEM investigations revealed that ore minerals are essentially, arsenopyrite, pyrite, chalcopyrite, pyrrhotite, hematite, goethite and magnetite with Au, Ag and Pt trace metals. Gangue minerals are mainly adularia, quartz, sericite, alunite, tridymite, chlorite, phlogopite and smectite. Epithermal alteration is well zoned with four successive characteristic zones: (1) zone of quartz-adularia-sericite and rare alunite; (2) zone of kaolinite and plagioclase albitization; (3) intermediate zone of illite-sericite; (4) sapropelic alteration type zone of chlorite-smectite and rare illite. This can be interpreted as a telescoping of two different acidity epithermal phases; low sulfidation (adularia-sericite) and high sulfidation (quartz-alunite), separated in time or due to a gradual increase of fluids acidity and oxicity within the same mineralization phase. Brecciated macroscopic facies with fragments hosting quartz-adularia-sericite minerals (low-sulfidation phase) without alunite, support the last hypothesis. Geodynamic context and mineral alteration patterns are closely similar to those of Maria Josefa gold mine at SE of Spain which exhibit a volcanic-hosted epithermal ore deposit in a similar vein system, within rhyolitic ignimbrites, altered to an argillic assemblage (illite-sericite abundant and subordinate kaolinite) that grades outwards into propylitic alteration (Sanger-von Oepen et al. (1990)). Mineralogical and lithologic study undertaken in the volcanic host rock at Aïn El Araâr-Oued Belif reveals a typical epithermal low-sulfidation and high-sulfidation ore deposits with dominance of low-sulfidation. Host rocks in these systems range from silicic to

  4. High precision conformal radiotherapy employing conservative margins in childhood benign and low-grade brain tumours

    International Nuclear Information System (INIS)

    Jalali, Rakesh; Budrukkar, Ashwini; Sarin, Rajiv; Sharma, Dayananda S.

    2005-01-01

    Background and purpose: To report local control and follow up outcome data of high precision conformal radiotherapy in childhood brain tumours. Materials and methods: Between December 1999 and December 2002, 26 children (17 boys and 9 girls, median age 11.5 years) with incompletely excised or recurrent benign and low-grade brain tumours [13 craniopharyngiomas, 11 low-grade gliomas (LGG) and 2 others] were treated with three-dimensional (3D) conformal radiotherapy (CRT) (12 patients) and stereotactic conformal radiotherapy (SCRT) (14 patients). Gross tumour volume (GTV) included neuro-imaging based visible tumour and/or resected tumour bed. Clinical target volume (CTV) consisted of GTV + 5 mm margin and planning target volume (PTV) consisted of additional 5 mm margin for CRT and 2 mm for SCRT. Treatment was delivered with 3-9 conformal fixed fields to a median dose of 54 Gy/30 fractions. Results: The actuarial 2 and 3 year disease free and overall survival was 96 and 100%, respectively (median follow up: 25 months, range 12-47 months). Radiological follow up available in 25 patients revealed complete response in 1, partial regression in 10, stable disease in 13 and progression in 1 patient (within the CTV). One patient with craniopharyngioma on a routine imaging revealed a mild asymptomatic cyst enlargement, which resolved with conservative management. A patient with chiasmatic glioma developed cystic degeneration and hydrocephalus 9 months after SCRT requiring cyst drainage and placement of a ventriculoperitoneal shunt. Conclusion: High-precision conformal techniques delivering irradiation to a computer generated target volume employing 7-10 mm 3D margins beyond the visible tumour and/or resected tumour bed appear to be safe in children with incompletely resected or recurrent benign and low-grade brain tumours, based on these data

  5. Precursor lesions of high-grade serous ovarian carcinoma: morphological and molecular characteristics.

    Science.gov (United States)

    Gross, Amy L; Kurman, Robert J; Vang, Russell; Shih, Ie-Ming; Visvanathan, Kala

    2010-01-01

    The lack of proven screening tools for early detection and the high mortality of ovarian serous carcinoma (OSC), particularly high grade, have focused attention on identifying putative precursor lesions with distinct morphological and molecular characteristics. The finding of occult invasive and intraepithelial fallopian tube carcinomas in prophylactically removed specimens from asymptomatic high-risk BRCA 1/2-mutation carriers supports the notion of an origin for OSC in the fallopian tube. The intraepithelial carcinomas have been referred to as serous intraepithelial carcinomas (STICs) but our own findings (unpublished data) and recent reports have drawn attention to a spectrum of changes that fall short of STICs that we have designated serous tubal intraepithelial lesions (STILs).

  6. Precursor Lesions of High-Grade Serous Ovarian Carcinoma: Morphological and Molecular Characteristics

    Directory of Open Access Journals (Sweden)

    Amy L. Gross

    2010-01-01

    Full Text Available The lack of proven screening tools for early detection and the high mortality of ovarian serous carcinoma (OSC, particularly high grade, have focused attention on identifying putative precursor lesions with distinct morphological and molecular characteristics. The finding of occult invasive and intraepithelial fallopian tube carcinomas in prophylactically removed specimens from asymptomatic high-risk BRCA 1/2-mutation carriers supports the notion of an origin for OSC in the fallopian tube. The intraepithelial carcinomas have been referred to as serous intraepithelial carcinomas (STICs but our own findings (unpublished data and recent reports have drawn attention to a spectrum of changes that fall short of STICs that we have designated serous tubal intraepithelial lesions (STILs.

  7. Results after surgical treatment of liver metastases in patients with high-grade gastroenteropancreatic neuroendocrine carcinomas

    DEFF Research Database (Denmark)

    Galleberg, R B; Knigge, U; Tiensuu Janson, E

    2017-01-01

    Background: Gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are generally characterized by synchronous metastases, high aggressiveness and a dismal prognosis. Current international guidelines do not recommend surgical treatment of liver metastases, however the existing data are scarce......., particularly for the group with a Ki-67 in the relatively lower G3 range. Our findings indicate a possible role for surgical treatment of liver metastases in the management of this patient population.......Background: Gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are generally characterized by synchronous metastases, high aggressiveness and a dismal prognosis. Current international guidelines do not recommend surgical treatment of liver metastases, however the existing data are scarce....... The aim of this study was to evaluate the results of curatively intended resection/radiofrequency ablation (RFA) of liver metastases in patients with metastatic GEP-NEC. Methods: 32 patients with a diagnosis of high-grade gastroenteropancreatic neuroendocrine neoplasm (Ki-67 > 20%) and with intended...

  8. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-09-30

    Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. These binders and experimental procedures will be able to be used for use in improving the energy efficiency of

  9. A green preparation of Mn-based product with high purity from low-grade rhodochrosite

    Science.gov (United States)

    Lian, F.; Ma, L.; Chenli, Z.; Mao, L.

    2018-01-01

    The low-grade rhodochrosite, the main resources for exploitation and applications in China, contains multiple elements such as iron, silicon, calcium and magnesium. So the conventional preparation of manganese sulphate and manganese oxide with high purity from electrolytic product is characterized by long production-cycle, high-resource input and high-pollution discharge. In our work, a sustainable preparation approach of high pure MnSO4 solution and Mn3O4 was studied by employing low-grade rhodochrosite (13.86%) as raw material. The repeated leaching of rhodochrosite with sulphuric acid was proposed in view of the same ion effect, in order to improve the solubility of Mn2+ and inhibit the dissolution of the impurities Ca2+ and Mg2+. With the aid of theoretical calculation, BaF2 was chosen to remove Ca2+ and Mg2+ completely in the process of purifying. The results showed that the impurities such as Ca2+, Mg2+, Na+ were decreased to less than 20ppm, and the Ni- and Fe- impurities were decreased to less than 1ppm, which meets the standards of high pure reagent for energy and electronic materials. The extraction ratio and the recovery ratio of manganese reached 94.3% and 92.7%, respectively. Moreover, the high pure Mn3O4 was one-step synthesized via the oxidation of MnSO4 solution with the ratios of OH-/Mn2+=2 and Mn2+/H2O2=1.03, and the recovery rate of manganese reaches 99%.

  10. Permanent I-125 interstitial implant in the management of high grade CNS malignancies in children

    International Nuclear Information System (INIS)

    Vaishampayan, N.; Zamorano, L.; Aronin, P.; Gaspar, L.; Canady, A.; Lattin, P.; Ezzell, G.; Yakar, D.; Chungbin, S.; Fontanesi, J.

    1996-01-01

    Purpose/Objective: To evaluate the efficacy and complications associated with the use of permanent I-125 interstitial implants in children with high grade CNS malignancies. Materials and Methods: Between May of 1990 and September of 1994, fourteen children received permanent I-125 interstitial implant brachytherapy as initial therapy (n=8) or at time of recurrence (n=6). Histologies included Glioblastoma Multiforme (n=2), Anaplastic Astrocytoma (n=9) and others (n=3). Pre-implant surgical procedures included: Gross Total Resection (n=2), Subtotal Resection (n=8) or Biopsy alone (n=4). Six patients received pre-implant external beam irradiation (dose range 3,500-6500 cGy) and three patients received post-implant external beam irradiation (dose range 5,040-5,060 cGy). Implant dose range was 8,294-10,368 cGy over the lifetime of the implant (median 10,368 cGy). Results: At last follow-up (median 17.5 months; range 4-56 months), eight children were alive. Six out of the eight had no evidence of disease progression while the remaining had radiologic evidence of progression. Implant complications (n=2) included skin necrosis and bone flap infection. Conclusions: Based on this initial review, we continue to investigate the use of permanent I-125 interstitial brachytherapy in the treatment of high grade CNS malignancies in children and will discuss and compare these results with those of other 'Boost' series

  11. Detection of high-grade small bowel obstruction on conventional radiography with convolutional neural networks.

    Science.gov (United States)

    Cheng, Phillip M; Tejura, Tapas K; Tran, Khoa N; Whang, Gilbert

    2018-05-01

    The purpose of this pilot study is to determine whether a deep convolutional neural network can be trained with limited image data to detect high-grade small bowel obstruction patterns on supine abdominal radiographs. Grayscale images from 3663 clinical supine abdominal radiographs were categorized into obstructive and non-obstructive categories independently by three abdominal radiologists, and the majority classification was used as ground truth; 74 images were found to be consistent with small bowel obstruction. Images were rescaled and randomized, with 2210 images constituting the training set (39 with small bowel obstruction) and 1453 images constituting the test set (35 with small bowel obstruction). Weight parameters for the final classification layer of the Inception v3 convolutional neural network, previously trained on the 2014 Large Scale Visual Recognition Challenge dataset, were retrained on the training set. After training, the neural network achieved an AUC of 0.84 on the test set (95% CI 0.78-0.89). At the maximum Youden index (sensitivity + specificity-1), the sensitivity of the system for small bowel obstruction is 83.8%, with a specificity of 68.1%. The results demonstrate that transfer learning with convolutional neural networks, even with limited training data, may be used to train a detector for high-grade small bowel obstruction gas patterns on supine radiographs.

  12. Cerebral vasomotor reactivity and apnea test in symptomatic and asymptomatic high-grade carotid stenosis

    Directory of Open Access Journals (Sweden)

    Lučić-Prokin Aleksandra

    2015-01-01

    Full Text Available Introduction. Cerebral vasomotor reactivity (VMR represents an autoregulatory response of the arterial trunks on the specific vasoactive stimuli, most commonly CO2. Objective. The aim of this retrospective study was to compare VMR in high-grade symptomatic (SCAS and asymptomatic carotid stenosis (ACAS, using the apnea test to evaluate the hemodynamic status. Methods. The study included 50 patients who were hospitalized at the neurology and vascular surgery departments as part of preparation for carotid endarterectomy. We evaluated VMR by calculating the breath holding index (BHI in 34 patients with SCAS and 16 patients with ACAS, with isolated high-grade carotid stenosis. We evaluated the impact of risk factors and collateral circulation on BHI, as well as the correlation between the degree of carotid stenosis and BHI. Results. A pathological BHI was more frequent in the SCAS group (p<0.01. There was no difference in the range of BHI values between the groups, both ipsilaterally and contralaterally. Only male gender was associated with pathological BHI in both groups (p<0.05. Collateral circulation did not exist in over 60% of all subjects. We confirmed a negative correlation between the degree of carotid stenosis and BHI. Conclusion. SCAS and ACAS patients present with different hemodynamics. While ACAS patients have stable hemodynamics, combination of hemodynamic and thromboembolic effects is characteristic of SCAS patients.

  13. Teachers' Grading Decision Making

    Science.gov (United States)

    Isnawati, Ida; Saukah, Ali

    2017-01-01

    This study investigated teachers' grading decision making, focusing on their beliefs underlying their grading decision making, their grading practices and assessment types, and factors they considered in grading decision making. Two teachers from two junior high schools applying different curriculum policies in grade reporting in Indonesian…

  14. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Science.gov (United States)

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

    2011-02-01

    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  15. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; J. A. Gurtler; K. Lewandowski

    2005-09-30

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  16. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-03-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  17. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  18. Distribution of the ore elements in ore bodies of the Zapolyarnoe field (Kola Peninsula

    Directory of Open Access Journals (Sweden)

    D. V. Taymasov

    2017-12-01

    Full Text Available The author conducted studies of the chemical zonality of ore deposits of all types for the sulfide-copper-nickel deposit Zapolyarnoe. Within the deposit of sulfide-copper-nickel ores Zapolyarnoe are the following industrial types of ores: rich interspersed ores, which are interspersed mineralization in peridotites; brecciated ores formed by detrital material; poor interspersed ores characterized by vein-interspersed mineralization; solid ores in a form of massive sulphide emissions. This work is based on operational and detailed exploration data. The author sorted samples according to the types of ores. Using the results, the author derived regression lines and their formulas to rectilinear dependencies. Analysis of the graphs showed that for all types of ores the dependences of copper and cobalt content on nickel content are direct, but at that, in thick-interspersed and brecciated types they are similar, and in scattered-interspersed they differ significantly. It becomes clear that correlation of copper and nickel in ore body depends on the scattered-interspersed ores, whereas the correlation of cobalt and nickel is determined mainly by thick-interspersed and brecciated ores. Dependencies between nickel, copper and cobalt in ores change when concentration of nickel in the ore changes. The graphs also show that the ratio of Ni/Cu in breccias and scattered-interspersed ores, as well as in near-ore metaperidotites, is almost constant at different nickel concentrations, on average 2:1.5 and 1, respectively. Thick- interspersed ores show the tendency towards an increase in the ratio with an increase in nickel content. The Ni/Co ratio increases with an increase of Ni concentration in all types of ores. In rich ores, growth occurs along a stepped curve, and in breccias – rectilinearly. Thus, the analysis of distribution of ore elements in ore bodies indicates a complex heterogeneous composition of sulphide mineralizations in different types of ores

  19. Recent trends in research and development work on the processing of uranium ore in South Africa

    International Nuclear Information System (INIS)

    James, H.E.

    1976-07-01

    The rapid increases in the price of gold and uranium in recent years have coincided with an unprecedented increase in working costs at South African gold mines. A re-examination of the existing flowsheets for the recovery of uranium, gold, and pyrite from Witwatersrand ores, in the light of these economic trends, has resulted in the identification of a number of profitable areas for research and development. The main topics under investigation in South Africa in the processing of uranium ore are the use of physical methods of concentration such as flotation, gravity concentration, and wet high-intensity magnetic separation; the wider adoption of the 'reverse leach', in which prior acid leaching for uranium improves the subsequent extraction of gold; the use of higher leaching temperatures and higher concentrations of ferric ion in the leach to increase the percentage of uranium extracted, including the production of ferric ion from recycled solutions; the application of pressure leaching to the recovery of uranium from low-grade ores and concentrates; the development of a continuous ion-exchange contactor capable of handling dilute slurries, so that simpler and cheaper techniques of solid-liquid separation can be used instead of the expensive filtration and clarification steps, and the improvement of instrumentation for the control of additions of sulphuric acid and manganese dioxide to the leach. A brief description is given of the essential features of the new or improved processing techniques under development that hold promise of full-scale application at existing or future uranium plants [af

  20. Recent trends in research and development work on the processing of uranium ore in South Africa

    International Nuclear Information System (INIS)

    James, H.E.

    1976-01-01

    The rapid increases in the price of gold and uranium in recent years have coincided with an unprecedented increase in working costs at South African gold mines. A re-examination of the existing flowsheets for the recovery of uranium, gold and pyrite from Witwatersrand ores, in the light of these economic trends, has resulted in the identification of a number of profitable areas for research and development. The main topics under investigation in South Africa in the processing of uranium ore are the use of physical methods of concentration such as flotation, gravity concentration and wet high-intensity magnetic separation; the wider adoption of the 'reverse leach', in which prior acid leaching for uranium improves the subsequent extraction of gold; the use of higher leaching temperatures and higher concentrations of ferric ion in the leach to increase the percentage of uranium extracted, including the production of ferric ion from recycled solutions; the application of pressure leaching to the recovery of uranium from low-grade ores and concentrates; the development of a continuous ion-exchange contactor capable of handling dilute slurries, so that simpler and cheaper techniques of solid/liquid separation can be used instead of the expensive filtration and clarification steps, and the improvement of instrumentation for the control of additions of sulphuric acid and manganese dioxide to the leach. A brief description is given of the essential features of the new or improved processing techniques under development that hold promise of full-scale application at existing or future uranium plants

  1. Pleistocene apparent ages by U-Pb isotope and U-series methods for uranium ore in Dakota Sandstone near Gallup, New Mexico

    International Nuclear Information System (INIS)

    Ludwig, K.R.; Szabo, B.J.; Granger, H.C.

    1977-01-01

    Radiometric dates of a high-grade uranium ore from the Hogback No. 4 mine in Dakota Sandstone near Gallup, N. Mex., indicate a late Pleistocene age of mineralization. The 206 Pb/ 238 U and 207 Pb/ 235 U apparent ages of about 70,000 y and 100,000 y, respectively, are discordant, but are in broad agreement with the discordant 230 Th/ 238 U and 230 Pa/ 235 U apparent ages of 130,000 y and 78,000 y, respectively. Although it is not clear how the analyzed sample relates to the main period of mineralization at this mine, these dates are consistent with previous age limits suggested for Dakota Sandstone uranium ores

  2. Ore microscopy applied to beneficiation

    International Nuclear Information System (INIS)

    Hagni, R.D.

    1978-01-01

    Ore microscopy can be an important adjunct to beneficiation, because it can be used not only to predict mill problems of undeveloped ore deposits but to identify the causes for the loss of minerals in the products of operating mines and mills. Mineral distribution among various mill products can be determined by examining polished sections prepared from samples obtained from each step of the beneficiation process. The degree of liberation of each mineral can be quantitatively determined for each mill product by counting locked vs. free particles. For many beneficiation problems, the preparation of a few polished sections of carefully selected mill products can yield useful information, which the mill dressing engineer can effectively use to alleviate those problems

  3. Geology and ore deposits of the Section 23 Mine, Ambrosia Lake District, New Mexico

    Science.gov (United States)

    Granger, H.C.; Santos, E.S.

    1982-01-01

    The section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation in the Ambrosia Lake mining district during the early 1960s. The Ambrosia Lake district is one of several mining districts within the Grants mineral belt, an elongate zone containing many uranium deposits along the southern flank of the San Juan basin. Two distinct types of ore occur in the mine. Primary ore occurs as peneconcordant layers of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks and which are typically elongate in an east-southeast direction subparallel both to the sedimentary trends and to the present-day regional strike of the strata. These are called prefault or trend ores because of their early genesis and their elongation and alinement. A second type of ore in the mine is referred to as postfault, stacked, or redistributed ore. Its genesis was similar to that of the roll-type deposits in Tertiary rocks of Wyoming and Texas. Oxidation, related to the development of a large tongue of oxidized rock extending from Gallup to Ambrosia Lake, destroyed much of the primary ore and redistributed it as massive accumulations of lower grade ores bordering the redox interface at the edge of the tongue. Host rocks in the southern half of sec. 23 (T. 14 N., R. 10 W.) are oxidized and contain only remnants of the original, tabular, organic-rich ore. Thick bodies of roll-type ore are distributed along the leading edge of the oxidized zone, and pristine primary ore is found only near the north edge of the section. Organic matter in the primary ore was derived from humic acids that precipitated in the pores of the sandstones and fixed uranium as both coffinite and urano-organic compounds. Vanadium, molybdenum, and selenium are also associated with the ore. The secondary or roll-type ores are essentially free of organic carbon and contain uranium both as coffinite and

  4. The role of smoking and alcohol intake in the development of high-grade squamous intraepithelial lesions among high-risk HPV-positive women

    DEFF Research Database (Denmark)

    Tolstrup, Janne; Munk, Christian; Thomsen, Birthe Lykke

    2006-01-01

    BACKGROUND: Infection with human papillomavirus is considered a necessary factor in developing high-grade squamous intraepithelial lesions of the cervix. However, most human papillomavirus positive women do not develop high-grade squamous intraepithelial lesions and other factors may be important...... for this transition. The objective of the present study was to examine if smoking and alcohol intake are associated with the risk of developing high-grade squamous intraepithelial lesions in women positive for high-risk human papillomavirus types. METHODS: We used baseline information on exposures on 548 high......-risk human papillomavirus positive women with normal cytology, comparing 94 women who developed high-grade squamous intraepithelial lesions with 454 women who remained cytologically normal. Logistic regression was applied for statistical analysis. RESULTS: Compared with never smokers, the odds ratio for high...

  5. Radon risk in ore miners

    International Nuclear Information System (INIS)

    Beno, M.

    1997-01-01

    Underground workers are exposed to various clastogenic agents. One of these agents, radon, attracts attention of recent research as it causes lung cancer in the population occupationally exposed to its various concentrations especially in mine air of uranium mines or ore mines. This paper is a pilot study in which the numbers of chromosomal aberrations (CA) in lymphocytes of ore mines (Nizna Slana-iron ore, Hnusta-talc ore) located in east central Slovakia were followed and related to the lifetime underground radon exposure and to lifetime smoking. Seventy miners volunteering after an informed consent served as donors of venous blood. Twenty healthy pro-bands, age matched with the miners, which never worked underground (mostly clerks) served as donors of control blood samples. The exposure to radon and smoking has been estimated according to working-records and personal anamnesis. The findings unequivocally showed a small but statistically significant clastogenic effect of the exposure to underground environment of the mines concerned. This study has shown also a small but significant influence of smoking, which in the subgroup of miners working underground less than 1500 shifts may have acted synergically with the underground exposure. It was concluded tat: (1) Significantly higher counts of chromosomal aberrations in lymphocytes of 70 miners than in an age matched control group of 20 white-collar workers were found; (2) The higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; (3) The positive dependence of the number of chromosomal aberrations from the exposure to smoking was loose and it was expressed by significantly higher chromosomal aberrations counts in the group of miners working less than 1500 shifts underground; (4) A dependence of chromosomal aberrations counts from the exposure to radon could not be assessed. At relatively low numbers of pro-bands in subgroups it was not ruled out the confounding

  6. Increased variability of watershed areas in patients with high-grade carotid stenosis

    DEFF Research Database (Denmark)

    Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine

    2018-01-01

    . Despite of high relevance for both clinical diagnostics and research, individual in vivo WSA definition is fairly limited to date. Thus, this study proposes a standardized segmentation approach to delineate individual WSAs by use of time-to-peak (TTP) maps and investigates spatial variability...... of individual WSAs. Methods: We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit...... time atlas and individual super-selective arterial spin labeling. We compared spatial variability of WSA probability maps between groups and assessed TTP differences between hemispheres in individual and group-average watershed locations. Results: Patients showed significantly higher spatial...

  7. High Grade Glioma Mimicking Voltage Gated Potassium Channel Complex Associated Antibody Limbic Encephalitis

    Directory of Open Access Journals (Sweden)

    Dilan Athauda

    2014-01-01

    Full Text Available Though raised titres of voltage gated potassium channel (VGKC complex antibodies have been occasionally associated with extracranial tumours, mainly presenting as Morvan's Syndrome or neuromyotonia, they have not yet been reported to be associated with an intracranial malignancy. This is especially important as misdiagnosis of these conditions and delay of the appropriate treatment can have important prognostic implications. We describe a patient with a high grade glioma presenting with clinical, radiological, and serological features consistent with the diagnosis of VGKC antibody associated limbic encephalitis (LE. This is the first association between a primary brain tumour and high titre of VGKC complex antibodies. Clinicoradiological progression despite effective immunosuppressive treatment should prompt clinicians to look for alternative diagnoses. Further studies to elucidate a possible association between VGKC complex and other surface antigen antibodies with primary brain tumours should be carried out.

  8. Numerical calculation of high frequency fast wave current drive in a reactor grade tokamak

    International Nuclear Information System (INIS)

    Ushigusa, Kenkichi; Hamamatsu, Kiyotaka

    1988-02-01

    A fast wave current drive with a high frequency is estimated for a reactor grade tokamak by the ray tracing and the quasi-linear Fokker-Planck calculations with an assumption of single path absorption. The fast wave can drive RF current with the drive efficiency of η CD = n-bar e (10 19 m -3 )I RC (A)R(m)/P RF (W) ∼ 3.0 when the wave frequency is selected to be f/f ci > 7. A sharp wave spectrum and a ph|| >/υ Te ∼ 3.0 are required to obtain a good efficiency. A center peaked RF current profile can be formed with an appropriate wave spectrum even in the high temperature plasma. (author)

  9. Biology Procedural Knowledge at Eleventh Grade of Senior High School in West Lampung Based on Curriculum

    Science.gov (United States)

    Sari, T. M.; Paidi; Mercuriani, I. S.

    2018-03-01

    This study was aim to determine Biology procedural knowledge of senior high school in West Lampung based on curriculum at 11th grade in even semester. This research was descriptive research. The population was all students of senior high school in West Lampung. The sampling technique in this research used purposive sampling technique, so the researcher obtained 3 schools using K13 and 3 schools using KTSP. Data collecting technique used instrument test. Data analysis technique used U-Mann Whitney test. The result showed that p=0.028 (p<0.05), so there was significant differences between school using K13 and KTSP. The procedural knowledge of schools which using K13 is higher than school which using KTSP, with the mean score K13=4.35 and KTSP=4.00

  10. High grade glioma mimicking voltage gated potassium channel complex associated antibody limbic encephalitis.

    Science.gov (United States)

    Athauda, Dilan; Delamont, R S; Pablo-Fernandez, E De

    2014-01-01

    Though raised titres of voltage gated potassium channel (VGKC) complex antibodies have been occasionally associated with extracranial tumours, mainly presenting as Morvan's Syndrome or neuromyotonia, they have not yet been reported to be associated with an intracranial malignancy. This is especially important as misdiagnosis of these conditions and delay of the appropriate treatment can have important prognostic implications. We describe a patient with a high grade glioma presenting with clinical, radiological, and serological features consistent with the diagnosis of VGKC antibody associated limbic encephalitis (LE). This is the first association between a primary brain tumour and high titre of VGKC complex antibodies. Clinicoradiological progression despite effective immunosuppressive treatment should prompt clinicians to look for alternative diagnoses. Further studies to elucidate a possible association between VGKC complex and other surface antigen antibodies with primary brain tumours should be carried out.

  11. Karyometry detects subvisual differences in chromatin organization state between cribriform and flat high-grade prostatic intraepithelial neoplasia.

    Science.gov (United States)

    Montironi, Rodolfo; Thompson, Deborah; Scarpelli, Marina; Mazzucchelli, Roberta; Peketi, Prasanthi; Hamilton, Peter W; Bostwick, David G; Bartels, Peter H

    2004-08-01

    This digital texture analysis-based study evaluates the chromatin organization state in flat and cribriform high-grade prostatic intraepithelial neoplasia (PIN), in the adjacent normal looking secretory epithelium and in the co-occurring adenocarcinoma. Digital texture analysis (karyometry) was carried out on hematoxylin and eosin-stained sections from 24 radical prostatectomy specimens with high-grade PIN (12 with flat and 12 with cribriform architectural pattern, respectively) and cancer. Quantification was also conducted on the normal looking secretory epithelium. Discriminant analysis and the nonsupervised learning algorithm P-index were used to identify suitable subsets of features useful for the discrimination and classification of pathological groups and to explore multivariate data structure in the pathological subgroups. The average nuclear abnormality increases monotonically from the histologically normal appearing secretory epithelium to high-grade PIN and to adenocarcinoma. The nuclei from the so-called perimeter compartment of the flat high-grade PIN lesions show a higher nuclear abnormality compared to the nuclei of the cribriform high-grade PINs. Discriminant analysis shows that flat and cribriform high-grade PINs fall into two populations. Processing by the nonsupervised learning algorithm P-index revealed the existence of three well-defined, distinct subpopulations of nuclei of different chromatin phenotype. In the flat high-grade PIN lesions the proportions of nuclei in the three subpopulations are 16.5% (low abnormality), 25.0% (mid abnormality) and 58.5% (high abnormality), respectively. In the cribriform high-grade PIN lesions, 100% of the nuclei are in the mid-abnormality subpopulation. These differences are also discernible in the co-occurring adenocarcinoma and the histologically normal appearing secretory epithelium. To conclude, karyometry and statistical analysis detect the existence of distinct cell subpopulations of different chromatin

  12. The diagnostic value of high-frequency power-based diffusion-weighted imaging in prediction of neuroepithelial tumour grading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhiye; Liu, Mengqi [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Hainan Branch of Chinese PLA General Hospital, Department of Radiology, Sanya (China); Zhou, Peng [Chinese Academy of Sciences, Research Center for Brain-inspired Intelligence, Institute of Automation, Beijing (China); University of Chinese Academy of Sciences, Beijing (China); Lv, Bin [Academy of Telecommunication Research of MIIT, Beijing (China); Wang, Yan; Wang, Yulin; Lou, Xin; Ma, Lin [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Gui, Qiuping [Chinese PLA General Hospital, Department of Pathology, Beijing (China); He, Huiguang [Chinese Academy of Sciences, Research Center for Brain-inspired Intelligence, Institute of Automation, Beijing (China); University of Chinese Academy of Sciences, Beijing (China); Chinese Academy of Sciences, Center for Excellence in Brain Science and Intelligence Technology, Beijing (China)

    2017-12-15

    To retrospectively evaluate the diagnostic value of high-frequency power (HFP) compared with the minimum apparent diffusion coefficient (MinADC) in the prediction of neuroepithelial tumour grading. Diffusion-weighted imaging (DWI) data were acquired on 115 patients by a 3.0-T MRI system, which included b0 images and b1000 images over the whole brain in each patient. The HFP values and MinADC values were calculated by an in-house script written on the MATLAB platform. There was a significant difference among each group excluding grade I (G1) vs. grade II (G2) (P = 0.309) for HFP and among each group for MinADC. ROC analysis showed a higher discriminative accuracy between low-grade glioma (LGG) and high-grade glioma (HGG) for HFP with area under the curve (AUC) value 1 compared with that for MinADC with AUC 0.83 ± 0.04 and also demonstrated a higher discriminative ability among the G1-grade IV (G4) group for HFP compared with that for MinADC except G1 vs. G2. HFP could provide a simple and effective optimal tool for the prediction of neuroepithelial tumour grading based on diffusion-weighted images in routine clinical practice. (orig.)

  13. Prevalence of high astigmatism, eyeglass wear, and poor visual acuity among Native American grade school children.

    Science.gov (United States)

    Harvey, Erin M; Dobson, Velma; Miller, Joseph M

    2006-04-01

    The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism. Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O'odham Reservation. Noncycloplegic autorefraction was conducted on the right and left eye of each child using the Nikon Retinomax K+ autorefractor, and monocular recognition acuity was tested using ETDRS logarithm of the minimum angle of resolution (logMAR) letter charts. Tohono O'odham children had a high prevalence of high astigmatism (42% had > or = 1.00 D in the right or left eye) and the axis of astigmatism was uniformly with-the-rule. However, only a small percentage of children arrived at the vision screening wearing glasses, and the prevalence of poor visual acuity (20/40 or worse in either eye) was high (35%). There was a significant relation between amount of astigmatism and uncorrected visual acuity with each additional diopter of astigmatism resulting in an additional 1 logMAR line reduction in visual acuity. Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O'odham children. The results highlight the importance of improving glasses-wearing compliance, determining barriers to receiving eye care, and initiating public education programs regarding the importance of early identification and correction of astigmatism in Tohono O'odham children.

  14. Return-to-activity after anatomical reconstruction of acute high-grade acromioclavicular separation.

    Science.gov (United States)

    Saier, T; Plath, J E; Beitzel, K; Minzlaff, P; Feucht, J M; Reuter, S; Martetschläger, F; Imhoff, Andreas B; Aboalata, M; Braun, S

    2016-04-02

    To evaluate return-to-activity (RtA) after anatomical reconstruction of acute high-grade acromioclavicular joint (ACJ) separation. A total of 42 patients with anatomical reconstruction of acute high-grade ACJ-separation (Rockwood Type V) were surveyed to determine RtA at a mean 31 months follow-up (f-u). Sports disciplines, intensity, level of competition, participation in overhead and/or contact sports, as well as activity scales (DASH-Sport-Module, Tegner Activity Scale) were evaluated. Functional outcome evaluation included Constant score and QuickDASH. All patients (42/42) participated in sporting activities at f-u. Neither participation in overhead/contact sports, nor level of activity declined significantly (n.s.). 62 % (n = 26) of patients reported subjective sports specific ACJ integrity to be at least the same as prior to the trauma. Sporting intensity (hours/week: 7.3 h to 5.4 h, p = .004) and level of competition (p = .02) were reduced. If activity changed, in 50 % other reasons but clinical symptoms/impairment were named for modified behavior. QuickDASH (mean 6, range 0-54, SD 11) and DASH-Sport-Module (mean 6, range 0-56, SD 13) revealed only minor disabilities at f-u. Over time Constant score improved significant to an excellent score (mean 94, range 86-100, SD 4; p < .001). Functional outcome was not correlated with RtA (n.s.). All patients participated in sporting activities after anatomical reconstruction of high-grade (Rockwood Type V) ACJ-separation. With a high functional outcome there was no significant change in activity level (Tegner) and participation in overhead and/or contact sports observed. There was no correlation between functional outcome and RtA. Limiting, there were alterations in time spent for sporting activities and level of competition observed. But in 50 % those were not related to ACJ symptoms/impairment. Unrelated to successful re-established integrity and function of the ACJ it should be considered that

  15. Recurrent respiratory papillomatosis: HPV genotypes and risk of high-grade laryngeal neoplasia.

    Directory of Open Access Journals (Sweden)

    Turid Omland

    Full Text Available Patients with recurrent respiratory papillomatosis (RRP in Norway treated between 1987 and 2009 were recruited to this cohort study. They were followed from disease onset and data recorded until January 2012. Here, we describe the distribution of human papillomavirus (HPV genotypes, the prevalence of multiple HPV infections, and the risk of high-grade laryngeal neoplasia and respiratory tract invasive carcinoma in a large cohort of patients with RRP. We also examined whether HPV genotype, gender, age or clinical course are risk factors for this development. Clinical records and histological specimens were reviewed. Using formalin-fixed paraffin-embedded biopsies, HPV genotyping were performed by quantitative polymerase chain reaction assays identifying 15 HPV types. HPV-negative specimens were analyzed by metagenomic sequencing. Paraffin blocks were available in 224/238 patients. The DNA quality was approved in 221/224 cases. HPV DNA was detected in 207/221 patients and all were HPV 6 or HPV 11 positive, comprising HPV 6 in 133/207, HPV 11 in 40/207 cases and HPV 6/11 in 15/207 cases. Co-infection with one or two high-risk HPV types together with HPV 6 or HPV 11 was present in 19/207 patients. Metagenomic sequencing of 14 HPV-negative specimens revealed HPV 8 in one case. In total, 39/221 patients developed high-grade laryngeal neoplasia. 8/221 patients developed carcinoma of the respiratory tract (six patients with laryngeal carcinoma and two patients with lung carcinoma. High-grade laryngeal neoplasias were found more frequently in HPV-negative versus HPV-positive patients, (RR = 2.35, 95% CI 1.1, 4.99, as well as respiratory tract carcinomas (RR = 48, 95% CI 10.72, 214.91. In summary, the majority of RRP were associated with HPV 6 and/or 11. HPV-negative RRP biopsies occurred more frequently in adult-onset patients, and were associated with an increased risk of laryngeal neoplasia and carcinoma in the respiratory tract.

  16. The 9th Grade Shock and the High School Dropout Crisis

    Science.gov (United States)

    Pharris-Ciurej, Nikolas; Hirschman, Charles; Willhoft, Joseph

    2011-01-01

    Retrospective questions on educational attainment in national surveys and censuses tend to over-estimate high school graduation rates by 15 to 20 percentage points relative to administrative records. Administrative data on educational enrollment are, however, only available at the aggregate level (state, school district, and school levels) and the recording of inter-school transfers are generally incomplete. With access to linked individual-level administrative records from a very large “West Coast metropolitan school district” we track patterns of high school attrition and on-time high school graduation of individual students. Even with adjustments for the omission of out-of-district transfers (estimates of omission are presented), the results of this study show that failure in high school, as indexed by retention and attrition, are almost as common as on-time high school graduation. In addition to the usual risk factors of disadvantaged background, we find that the “9th grade shock”—an unpredicted decline in academic performance upon entering high school—is a key mechanism behind the continuing crisis of high school attrition. PMID:23017804

  17. High pre-transplant soluble CD30 levels are predictive of the grade of rejection.

    Science.gov (United States)

    Rajakariar, Ravindra; Jivanji, Naina; Varagunam, Mira; Rafiq, Mohammad; Gupta, Arun; Sheaff, Michael; Sinnott, Paul; Yaqoob, M M

    2005-08-01

    In renal transplantation, serum soluble CD30 (sCD30) levels in graft recipients are associated with increased rejection and graft loss. We investigated whether pre-transplant sCD30 concentrations are predictive of the grade of rejection. Pre-transplant sera of 51 patients with tubulointerstitial rejection (TIR), 16 patients with vascular rejection (VR) and an age-matched control group of 41 patients with no rejection (NR) were analyzed for sCD30. The transplant biopsies were immunostained for C4d. The median sCD30 level was significantly elevated in the group with VR (248 Units (U)/mL, range: 92-802) when compared with TIR (103 U/mL, range: 36-309, psCD30 levels compared to NR. Based on C4d staining, a TH2 driven process, the median sCD30 levels were significantly raised in C4d+ patients compared with C4d- group (177 U/mL vs. 120 U/mL, psCD30 levels measured at time of transplantation correlate with the grade of rejection. High pre-transplant levels are associated with antibody-mediated rejection which carries a poorer prognosis. sCD30 could be another tool to assess immunological risk prior to transplantation and enable a patient centered approach to immunosuppression.

  18. Neurocognitive training in patients with high-grade glioma: a pilot study.

    Science.gov (United States)

    Hassler, Marco Ronald; Elandt, Katarzyna; Preusser, Matthias; Lehrner, Johann; Binder, Petra; Dieckmann, Karin; Rottenfusser, Andrea; Marosi, Christine

    2010-03-01

    Although their neurocognitive performance is one of the major concerns of patients with high-grade gliomas (HGG) and although neurocognitive deficits have been described to be associated with negative outcome, neurocognitive rehabilitation is usually not integrated into the routine care of patients with malignant gliomas. In this pilot trial, a weekly group training session for attention, verbal, and memory skills was offered to patients with HGG with pre and post-training evaluation. Eleven patients, six with glioblastoma multiforme and five with WHO grade III gliomas, median age 50 years, with a Karnofsky performance score of 80-100 participated in ten group training sessions of 90 min. For evaluation at baseline and after the training by a neuropsychologist not involved in care or training of the patients, Trail Making Tests A and B (TMTA and TMTB), Hopkins Verbal Learning Test (HVLT), and the Controlled Oral Word Association Test (COWA) were used. Comparison of mean group differences between baseline and at post-training evaluation after 12 weeks revealed improvement across all neurocognitive variables. The patients showed a great diversity in their performances, with worsening, improvement, and stabilization. However, a significant group difference was detected only for the HVLT (score 19.6 +/- 8.9 at baseline, 23.6 +/- 8.8 after 12 weeks, P = 0.04). This pilot study shows that neurocognitive training in patients with HGG is feasible as group training with weekly sessions and might be able to induce improvements in attention and memory skills.

  19. High-speed potato grading and quality inspection based on a color vision system

    Science.gov (United States)

    Noordam, Jacco C.; Otten, Gerwoud W.; Timmermans, Toine J. M.; van Zwol, Bauke H.

    2000-03-01

    A high-speed machine vision system for the quality inspection and grading of potatoes has been developed. The vision system grades potatoes on size, shape and external defects such as greening, mechanical damages, rhizoctonia, silver scab, common scab, cracks and growth cracks. A 3-CCD line-scan camera inspects the potatoes in flight as they pass under the camera. The use of mirrors to obtain a 360-degree view of the potato and the lack of product holders guarantee a full view of the potato. To achieve the required capacity of 12 tons/hour, 11 SHARC Digital Signal Processors perform the image processing and classification tasks. The total capacity of the system is about 50 potatoes/sec. The color segmentation procedure uses Linear Discriminant Analysis (LDA) in combination with a Mahalanobis distance classifier to classify the pixels. The procedure for the detection of misshapen potatoes uses a Fourier based shape classification technique. Features such as area, eccentricity and central moments are used to discriminate between similar colored defects. Experiments with red and yellow skin-colored potatoes have shown that the system is robust and consistent in its classification.

  20. Relationship between collapse history and ore distribution in Sage Breccia pipe, northwestern Arizona

    International Nuclear Information System (INIS)

    Brown, N.A.; Mead, R.H.; McMurray, J.M.

    1989-01-01

    The Sage pipe is similar to other collapse breccia pipes in northern Arizona which have their beginnings in cave systems in the Redwall Limestone. Stoping of successively younger units caused the upward propagation of the pipe and provided the pipe-filling breccia. The Sage pipe extends at least 2,500 ft (762 m) vertically; the horizontal dimensions range from 100 to 300 ft (30.5-91 m), depending on variations in the adjoining host stratigraphy. The composition and distribution of breccia facies suggest a complex collapse history and variability in the mechanics of collapse. Rock failure took place both by block stoping and by decementation of sandstone and siltstone followed by flow of unconsolidated grains. The resulting breccias range from matrix to fragment-dominated, to sand flow breccia resulting from flow of individual grains. Episodic secondary collapse or readjustment within the breccia pile complicated facies distribution. Paragenetic studies indicate multiple periods of mineralization at Sage resulting in enrichment in an extensive suite of elements. Ore-grade uranium mineralization extends vertically for nearly 700 ft (213 m). Lateral distribution of the ore is variable and is directly related to breccia facies distribution. In generally, the more permeable breccias tend to be the most highly mineralized. Fracture, intergranular, and interfragment permeability were important to mineral distribution. Breccia continuity or plumbing was also important to lateral and vertical mineral distribution