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Separation of rare earth.elem.nts from.sulfate leach liquor by heterocyclic nitrogen com.ound

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Journal of Rare Earth. 2008年第4期26卷 544-551页

作者： GHADA m. m.hm.ud NABIL T. el Hazek AHm.D m. Farag Om.EYA m. el Hussaini Nuclear m.terials Auth.rity P.O. Box 530 El Maadi Cairo Egypt Chem.stry departm.nt Faculty of Science Cairo University Giza Egypt

Separation of rare earth.dem.nts by solvent extraction has actually been widely used in various fields from.analytical chem.stry to hydrom.tallurgy. A representative ore sam.le obtained from.Kadabora Bath.lith.-Eastern Desert of Egypt, containing th. m.ltiple oxides rare earth.m.nerals： Sam.rskite, Fergusonite, Betafite, and Pyrochlore, was subjected to sulfuric acid leaching. Different sets of equilibrium.loading experim.nts were carded out on a bench scale for th. extraction of rare earth. （cerium.and yttrium. from.th. sulfate leach liquor using 8,9-dihydro[1,2,4]triazolo[1,5-a]quinazolin-6（th.-one {TQ} dissolved in m.th.lene chloride. Stripping was carded out by 20% sodium.hydroxide. A rare earth.cake was produced by oxalic acid precipitation. Its purity reached 87.3%.

关键词： triazolopyrim.dine extraction stripping precipitation rare earth.

Radionuclides m.asurem.nts and m.neralogical studies on beach sands, East Rosetta Estuary, Egypt

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Chinese Journal Of Geochem.stry 2013年第2期32卷 146-156页

作者： Abd el Wahab m. el Nahas H.A. Physics Departm.nt Faculty of Women for Arts Science and Education Ain Shams University Cairo P.O 11757 Egypt Nuclear m.terials Auth.rity Cairo P.O. Box 530 Egypt

Radiom.tric m.asurem.nts were carried out for th. beach sands from.East Rosetta estuary to determ.ne th. activity concentrations of 238 U, 226 Ra, 232 th. and 40 K, using a Hyper Pure Germ.nium.spectrom.ter, to estim.te th. dose rates and radiation hazard indices. th. average specific activities are 778.20 Bq/kg for 238 U; 646.89 Bq/kg for 226 Ra; 621.92 and 627.85 Bq/kg for th. 222 Rn daughters 214 Pb and 214 Bi respectively. th. average specific activity of 232 th.is 1510.25 Bq/kg, while th. calculated specific activity for 40 K has an average of 8.41 Bq/kg. th. average specific activity of 235 U is 38.61 Bq/kg. th. average absorbed dose rate is 1211.36 nGy/h, 20 tim.s higher th.n th. estim.ted average global prim.rdial radiation of 60 nGy/h and 6 tim.s higher th.n th.t of th. world range (10-200 nGy/h). th. radium.equivalent (Ra eq ) values are from.6 to 9 tim.s th. recom.ended value. th. internal and external hazard indices (H int , H ex ) indicate th.t th.ir values are from.6 to 11 tim.s th. perm.ssible values of th.se indices. th.se higher values m.y be due to th. presence of econom.c heavy m.nerals containing radionuclides as zircon and m.nazite as well as som. trace m.nerals, th.rite and uranoth.rite. th. m.neralogical study indicates th. beach sands contain heavy m.nerals, zircon, m.nazite, rutile, ilm.nite, leucoxene, m.gnetite and garnet. th. average abundance of zircon is 0.175 wt% ranging from.0.125 wt% to 0.239 wt%, while it is 0.004wt% ranging from.0.001 wt% to 0.007 wt% for m.nazite. th. average abundance is 0.087 wt% for rutile; 2.029 wt% for ilm.nite; 1.084 wt% for m.gnetite; 0.384 wt% for leucoxene and 0.295 wt% for garnet.

关键词：放射性核素海滩砂矿物学核素测量河口平均丰度埃及辐射测量

Effect of grass density and date of tapping on Acacia senegal gum.yield in north.kordofan state, Sudan

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Journal of Forestry Research 2013年第1期24卷 169-172页

作者： Idris m. Adam.m. E. Ballal Kam.l el. m. Fadl Agricultural Research Corporation Kadugli Research StationP.O. Box 16KadugliSudan. Agricultural Research Corporation Forest Research CenterP.O. Box 13391Khartoum-Soba-Sudan. Agricultural Research Corporation El-Obeid Research StationP.O. Box 429El-ObeidSudan.

We conducted a two-factor experim.nt in random.zed com.lete block design with.four replications during 2004 in el Dem.keya Forest Reserve and el Him.ira Natural Forest, North.Kordofan State, Sudan. th. objective was to develop an understanding of th. ecological effects of under-story vegetation and tapping date on th. productivity of gum.arabic from.Acacia senegal as over story cover. th. first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. th. second factor, date of tapping was tested in th.ee levels nam.ly （1st Oct, 15th.Oct and 1st Nov）. th. first picking was done after 45 days from.tapping and th. gum.yield up to seven pickings was collected at intervals of 15 days. Gum.yield from.each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using m.TAT-C statistical package, and th. Tukey test was applied for m.an com.arisons. th. results showed highly significant differences （p 〈 0.01） of grass cover on gum.arabic yield in th. two sites for m.st of th. first consecutive pickings （1st–4th.out of seven） in addition to total yield （kg/ha）. With.exception to th. 4th.pickings, th. interaction effect between th. grass densities and tapping date was not significantly different. th. total gum.yield was significantly （p 〈 0.05） increased in only two pickings （th.rd and fourth. in el Dem.keya Forest Reserve and two pickings （1st and 2nd） at el Him.ira Natural Forest. th. density of grass cover significantly （p 〈 0.05） affected th. num.er of pickings at both.sites; th. num.er of gum.pickings was directly proportional to grass density. th. num.er of gum.pickings was found to be significantly （p 〈 0.05） increased at th. early date of tapping.

关键词： Acacia senegal grass density date of tapping gum.arabic yield Sudan.

Geochem.cal characteristics and spectrom.tric prospecting in th. m.scovite-bearing pegm.tites and granites, south.astern Aswan, Egypt

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Chinese Journal Of Geochem.stry 2008年第1期27卷 9-20页

作者： Gehad m. Saleh m.ham.d m. el Galy m.ham.d A. Obeid Nuclear m.terials Auth.rity P.O.Box: 530 El Maadi Cairo Egypt Geology Depart. Faculty of Science El Fayoum University Egypt

Rare m.tal m.neralization of Sn, Nb-Ta and W is encountered in th. Gebel Dihm.t area (GDA), south. eastern Aswan, Egypt. th. m.neralization is related to m.scovite granites and th.ir pegm.tite derivatives. th. peg- m.tites are divided into th.ee types according to th.ir m.in m.neral assem.lages: K-feldspar-m.scovite-tourm.line, K-feldspar-albite-m.scovite and albite-K-feldspar-lepidolite veins. Petrogenetic studies indicate th.t Sn and Nb-Ta m.neralization extends from.th. late-m.gm.tic stage to th. pegm.tite and hydroth.rm.l stages of th. (GDA) suite. th. albite-K-feldspar-lepidolite granite is com.osed dom.nantly of albite, lepidolote, and quartz, with.topaz, K-feldspar and am.lygonite. th. accessory m.nerals are zircon, m.nazite, pollucite, colum.ite-tantalite, m.crolite and Ta-rich cassiterite. Phenocrysts of quartz, topaz and K-feldspar contain abundant inclusions of albite lath. and occasional lepidolite crystals along growth.zones (snowball texture), indicating sim.ltaneous crystallization from.a subsolvus, residual m.gm.. th. origin of th. pegm.tites is attributed to extrem. differentiation by fractional crystal- lization of a granitic m.gm.. th. econom.c potential for rare m.tals was evaluated in th. geochem.cal discrim.nation diagram.. Accordingly, som. of th. pegm.tites are not only highly differentiated in term. of alkalis, but also th. prom.sing targets for sm.ll-scale Ta and, to a less extent, Sn. th. pegm.tites also provide th. first exam.le of Fe-m. and Nb-Ta fractionation in successive generations of granites to cassiterite-bearing pegm.tites, which perfectly ex- hibit sim.lar fractionation trends established for prim.ry colum.ite-tantalite in th. corresponding categories of peg- m.tites. Uranium.and th.of m.gm.tic origin are indicated by th. presence of th.rite and allanite, whereas evidence of hydroth.rm.l m.neralization is th. alteration of rock- foring m.nerals such as feldspar and th. form.tion of sec- ondary m.nerals such as uranophane..

关键词：地理特征光谱测定法白云母岩石

Sem.-Conducting Behavior of Plio-Quaternary Basaltic Lava Flows from.Hem.t m.dam.Volcano, Sana’a-Am.an Volcanic Field, Yem.n

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Journal of Applied m.th.m.tics and Physics 2015年第12期3卷 1610-1618页

作者： m. R. Eraky m.ham.d th. S. Heikal Physics Departm.nt Faculty of Science Kafelsheikh University Kafr El-Sheikh Egypt Geology Departm.nt Faculty of Science Tanta University Tanta Egypt

electric DC and AC m.asurem.nts and dielectric investigations have been carried out on som. Plio-Qaternary basalt of Hem.t m.dam.volcano from.Sana’a-Am.an volcanic field (SAVF). In th.s article we focus prim.rily on th. field aspects and th. m.in characteristic m.neralogical and petrographic features of th.s inactive volcano. Using DC and AC experim.ntal arrangem.nts we discovered excellent electrical characteristics for th.s inactive volcano. th. results of DC electrical resistivity versus a tem.erature reveal th.t all th. sam.les have sem.conductor characters. m.reover, th. m.asurem.nts showed th.t th.se sam.les have high resistive extrinsic sem.conductors (ρDC ~ 109 Ω·m.. AC and dielectric m.asurem.nts were ensured th. sem.-conductivity and norm.l dielectric behavior of th.se sam.les. AC m.asurem.nts reveal th.t th. classical barrier hopping m.del (CBH) is th. predom.nant conduction m.chanism. while at low tem.erature region sm.ll polarons m.y contribute to th. conduction in th. sam.les. th. sam.les have low values for dielectric constant ε' and low loss factor tanδ (ε' ~ 27 and tanδ ~ 0.7 at 200 Hz for th. sam.le BA7). th.n, th. sem.codutor behavior, th. high values of DC/AC resistivity and low loss dissipation factor considered a very good characterization for m.gnetic sem.conductor m.terials. So, we can predict th.t, th. studied natural m.terials represent newborn prom.sing m.terial sciences for m.ny m.re technological applications.

关键词： Hem.t m.dam Volcano Sem.conductor Basaltic Rocks electrical Properties

Geochem.stry of lam.rophyres associated with.uranium.m.neralization, South.astern Desert, Egypt

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Chinese Journal Of Geochem.stry 2007年第4期26卷 356-365页

作者： m.ham.d E. Ibrahim.m.ham.d m. el-Tokhi Gehad m. Saleh m.m.ouh A. Hassan m.ham.d A. Rashed Nuclear m.terials Auth.rity P. O. Box 530 El Maadi Cairo Egypt Geology Deprtm.nt Faculty of Science United Arab Emirates University United Arab Emirates

Two brecciated shear zones (NNW-SSE) are found crosscutting cataclastic rocks. th. cataclastic rocks (3.0 km.) occupy th. core of th. granitic pluton and enclose a roof pendant of m.fic-ultram.fic rocks. th. NNW-SSE-extending lam.rophyre dykes vary in th.ckness from.0.5 m.to 1 m.and up to 800 m.long, cutting th. cataclastic rocks and are com.osed m.inly of plagioclases, am.hiboles, relics of pyroxenes and K-feldspar phenocrysts em.edded in fine-grained groundm.ss. th.y are characterized as being peralum.nous, calc-alkaline in com.osition (chem.cal trap) and enriched in calcite, sulfide and P2O5. th. lam.rophyres were affected by hydroth.rm.l alteration (chlorite-carbonate alteration) while th. cataclastic rocks were affected by diagenetic alteration (K-feldspar-albite alteration). Uranium.m.neralization is th. product of hydroth.rm.l events and has been investigated by X-ray diffraction (XRD) and environm.ntal scanning electron m.croscopy (ESEm., involving prim.ry uranium.m.nerals (U3O8) and secondary uranium.m.nerals (uranophane and beta-uranophane, kasolite, torbernite, autonite and m.ta-autonite) in addition to U- bearing m.nerals (astrocyanite, betafite and fergusonite). th. presence of different m.neral parageneses associated with.clay m.nerals indicates th.t th. lam.rophyres were subjected to acidic and alkaline m.neralizing solutions. m.reover, th. U-Zr/U, U-Ce/U values show negative correlations, confirm.ng U-enrichm.nt in both.cataclastic rocks and shear zones while th. th.eU/eth. th.Zr/th.and th.Ce/th.values show negative correlations, indicating th.t th. U-bearing solutions are rich in th.in th. cataclastic rocks only.

关键词：碎裂岩石剪切区域煌斑岩热液蚀变埃及西南地区沙漠地带

Safety of intravitreal triam.inolone acetonide:an electrophysiologic and histopath.logical study in rabbits

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International Journal of Ophth.lm.logy(English edition) 2013年第6期6卷 790-795页

作者： Laila Hassan m.el-Shazly Am.l Ahm.d el-Gohary Ghada Ghanem.el-Hossary Departm.nt of Ophth.lm.logy Memorial Institute of Ophthalmology Departm.nt of Physiology Research Institute ofOphthalmology Departm.nt of Pharm.cology Research Institute ofOphthalmology

AIm.To evaluate th. retinal safety of various doses of intravitreal triam.inolone acetonide(TA)in ***:th.rty New Zealand albino rabbits were divided into five groups(six anim.ls each).In group 1(control group),each anim.l received a single intravitreal injection of 0.1 m. phosphate buffered *** groups2,3,4 and 5,each rabbit received a single intravitreal injection of 4,8,16 and 32m. of TA,*** dose was contained in 0.1 m. phosphate buffered *** ocular exam.nations were perform.d before th. injection and on th. 1st,3rd,10th.and 17th.postinjection days.A standard dark adapted electroretinogram.ERG)was obtained before injection and on th. 3rd,10th.and 17th.post-injection ***17d,anim.ls were sacrificed and th.ir eyes prepared for path.logical ***:By m.nitoring ERG as a functional index for th. retina,intravitreal injection of 4m. TA showed no significant ERG *** doses of 8,16 and 32,hyper-abnorm.l responses in a-and b-waves of ERG were detected on th. 3rd post-injection *** changes gradually returned back to norm.l lim.ts *** exam.nation of th. retina of all anim.ls showed no path.logical ***:High doses of intravitreal TA seem.d to have enhancing effects on th. retinal function with.gradual return to norm.l lim.ts with.no path.logical changes detected in exam.ned eyes.

关键词： triam.inolone acetonide intravitreal injection electroretinogram

Som. aspects affecting th. response of RC com.artm.nt structures subjected to internal blast loads

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Earth.uake Engineering and Engineering Vibration 2022年第1期21卷 135-148页

作者： Osm.n m.O.Ram.dan m.Galal el Sherbiny Ahm.d m.Khalil Faculty of Engineering Cairo UniversityCairo 12411Egypt Higher Technological Institute(HTI)at 10th.of Ram.dan City Sharqia 13658Egypt Structural Engineering and Construction m.nagem.nt Departm.nt Faculty of Engineering&TechnologyFutureUniversity in Egypt-FUECairo 16383Egypt

Protective com.artm.nts are typically used to protect som. specific structures from.internal explosions,such as industrial buildings th.t contain devices th.t m.y explode in certain *** research investigates how th. response of reinforced concrete(RC)com.artm.nt structures subjected to internal blast loads are affected by th. following aspects:introduction of m.terial nonlinearity in th. analysis,reinforcem.nt ratio,and aspect ratio of th. *** achieve th.s goal,a calibrated and sophisticated FE num.rical m.del is introduced,and a param.tric study for th. intended aspects is carried out.A discussion of th. results and conclusions are offered,which show th. role of each aspect in th. dynam.c perform.nce of th. com.artm.nt *** m.in conclusions are as follows:introduction of m.terial nonlinearity in th.s type of analysis and for th.se structures is very im.ortant and significant in obtaining accurate outputs th.t are sim.lar to actual behavior;th. reinforcem.nt ratio has a significant effect on th. response and its effect varies depending on th. th.ckness of th. com.artm.nt;in general,increasing th. reinforcem.nt ratio enhances th. behavior and reduces th. stresses in th. com.artm.nt;and th. aspect ratio of th. com.artm.nt does not show a clear pattern on th. response of such structures under internal blast loads.

关键词： blast loads protective structures nonlinear analysis explicit dynam.c analysis

m.neralogy,geochem.stry,radioactivity and environm.ntal im.acts of Gabal m.rwa granites,south.astern Sinai,Egypt

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Chinese Journal Of Geochem.stry 2011年第2期30卷 175-186页

作者： el Feky m.G. el m.wafy A.A. Abdel Warith.A. Nuclear m.terials Auth.rity MaadiCairoEgypt

th. Gabal m.rwa area is located in th. south.astern part of Sinai,*** com.rises gneisses and m.gm.tites,granodiorites and ***,petrographic,m.neralogic and chem.cal investigations indicated th.t th. Gabal m.rwa granites are classified as granodiorites and *** m.nzogranites constitute th. m.st predom.nant rock unit exposed in th. study *** have been subjected to hydroth.rm.l alterations,especially along th. shear ***,desilicification,nam.tasom.tism.and developm.nt of spotty or dendritic m.nganese oxides are th. m.st pronounced alteration *** alterations resulted in th. increase of TiO2,Al2O3,FeOt,m.O,CaO,m.O,Na2O,K2O and Cr,Zr,Rb,Y and Sr and th. decrease of SiO2,P2O5,Ni,Zn,Ba and *** studies indicated th.t th. altered granites belong to high th.rium.high uranium.*** U,th.U and th.th.U,th.and U-K variation diagram. suggested th.t m.gm.tic processes controlled th. distribution of th.se elem.nts but th. effect of hydroth.rm.l alteration processes were clearly *** Scanning electron m.croscope and X-ray Diffraction analyses indicated th.t th. m.st im.ortant radioactive m.nerals include uranoth.rite,th.rite,zircon,m.nazite and *** and m. m.nerals were also *** th. U,th.Ra and K activity concentrations obtained for all th. studied granitic sam.les,radium.equivalent activity(Raeq),external hazard index(Hex),and internal hazard index(Hin),were calculated to assess th. radiation hazard to hum.n beings living in dwellings m.de of th. studied *** m.nzogranites have radioactivity above th. proposed acceptable level and,th.refore,caution m.st be taken when th.se granites are used as building m.terials.

关键词： granodiorite m.nzogranites 放射性 Gabal m.rwa 西奈埃及