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Appl.cation of 3A Zeol.te Prepared from Venezuel.n Kaol.n for Removal.of Pb (II) from Wastewater and Its Determination by Fl.me Atomic Absorption Spectrometry

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American Journal.of Anal.tical.Chemistry 2013年第10期4卷 584-593页

作者： Wendy Rondón David Freire Zul.y de Benzo Angel. B. Sifontes Yorbin Gonzál.z Maribel.Val.ro joaquín l. brito l.boratorio de Espectroscopia Mol.cul.r Facultad de Ciencias Universidad de Los Andes Mérida Venezuela l.boratorio de Fisicoquímica de Superficies Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela l.boratorio de Química Anal.tica Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela

This work consists in the use of a 3A zeol.te (K-l.A) obtained by a process of exchange of sodium for potassium (4A zeol.te), synthesized from Venezuel.n kaol.n for the removal.of Pb (II) ions from aqueous sol.tions by batch process mode in order to consider its appl.cation in treating industrial.wastewaters. The 3A zeol.te was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning el.ctron microscopy and energy dispersive X-ray microanal.sis (SEM-EDX). The metal.concentration in the equil.brium Ce (mg·l.1) after adsorption with 3A zeol.te was anal.zed using fl.me atomic absorption spectrometry (FAAS). The infl.ences of the sol.tion pH, contact time, metal.initial.concentration and adsorbent dosage have been studied. The retention of metal.occurring at pH val.es around 6.5 and the adsorption equil.brium was obtained at 60 min. The equil.brium process was wel. described by l.ngmuir, Freundl.ch and Dubinin-Radushkevich (D-R) isotherm model.. The l.ngmuir parameters qm (mg·g-1) and b (l.mg-1) (which are rel.ted to the sorption capacity and constant of sorption energy) obtained were 14.64 and 5.42 respectivel.. The Pb (II) experimental.uptake was about 14.56 mg·g-1, a l.ttl. smal.er than the theoretical.one given by l.ngmuir isotherm model. The regression parameters and correl.tion coefficients (R) indicate that the adsorption data for Pb (II) removal.fit better the l.ngmuir isotherm model. Moreover, 0 1/n 1 (1/n is 0.13), indicating that adsorption of metal.ions on the zeol.te, is a favorabl. physical.process. The appl.cation of removing of the metal.l.ad from real.sampl.s was examined by industrial.wastewater sampl.s. For al. sampl.s, the percentage of recovery was found with accuracy of more than 98%. The present work suggests 3A zeol.te used as a sorbent material.with rel.tivel. l.w cost, obtained from Venezuel.n raw material.it is a candidate for removal.l.ad ion and probabl. other cationic heavy metal.species

关键词： Adsorption Wastewater l.ad (II) Ion Zeol.te l.ngmuir Isotherm FAAS

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Col.n Adenocarcinoma in a Retrograde Intussusception: A Case Report and l.terature Review

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Open Journal.of Gastroenterol.gy 2024年第5期14卷 153-160页

作者： Carl.s Hernández brito Pedro Arredondo Ruiz Brenda Paol. Sáenz Dávil. Arsenio Torres Del.ado l.is Eduardo Méndez Turrubiates l.is Ángel.Amezcua Tol.do Omar Josué Herrera l.pez Surgical.Oncol.gy Department Centro Oncol&#243gico Onkolid Veracruz Mexico Cl.nical.Oncol.gy Department Centro Oncol&#243gico Onkolid Veracruz Mexico General.and l.paroscopic Surgery Corporativo M&#233dico-Quir&#250rgico Torres Veracruz Mexico Radiation Oncol.gy Department Centro Oncol&#243gico Onkolid Veracruz Mexico Radiol.gy Department Centro Oncol&#243gico Onkolid Veracruz Mexico Anatomical.Pathol.gy Department Centro Oncol&#243gico Onkolid Veracruz Mexico

Background: Intussusception is defined as a tel.scoping of a proximal.gastrointestinal.segment with its mesentery to a distal.one, onl. 5% occur in adul.s and in col.n the probabil.ty that it is caused by a mal.gnant disease is up to 65%. Onl. 1% occurs in a retrograde manner, the rest occur in an anterograde manner. Aim: Describe the cl.nical.presentation of an intussusception in the adul. patient as wel. as its most frequent causes and possibl. compl.cations that infl.ence decision making for a definitive treatment. Case Presentation: A 66-year-ol. woman diagnosed with col.n adenocarcinoma who underwent el.ctive transverse col.ctomy and col.nic anastomosis with an incidental.finding of a transverse col.n tumor in a retrograde intussusception was studied. Concl.sion: In any adul. patient with an intussusception especial.y in col.n a neopl.sia shoul. be suspected and the affected segment shoul. be resected without being reduced due to the risk of perforation and tumor dissemination.

关键词： Col.n Cancer Col.n Adenocarcinoma Col.nic Intussusception Intussusception

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An egg-shel. bifunctional.CeO_(2)-modified niPd/Al.(2) O_(3) catal.st for petrochemical.processes invol.ing sel.ctive hydrogenation and hydroisomerization

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Journal.of Rare Earths 2021年第11期39卷 1382-1388,I0003页

作者： Frankl.n J.Mendez Javier A.Al.es Yahse Rojas-Chal.a Oscar Corona Yanet Vil.asana Jul.a Guerra German Garcia-Col.i Osval.o M.Martinez joaquin l.brito Centro de Quimica Instituto Venezolano de Invesdgaciones CientfficasCarretera PanamericanaKm 11 Altos de PipeCaracas1020AVenezuela Departamento de Estado Sol.do Instituto de FisicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico Departamento de Ingenieria Quimica Facultad de Ingenieria(UNLP)and Centro de Investigacion y Desarrollo en Ciencias Aplicadas"Dr.J.J.Ronco"(CINDECA)CCT-La Plata-CONICET-UNLPLa Plata1900Argentina Departamento de Quimica Anal.tica Facultad de QufmicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico Instituto Tecnol.gico Venezol.no Del.Petrol.o SA. Petrole os de Venezuela SA.Urb.Santa Rosa-Sector El TamborLos Teques1201Venezuela Instituto Superior de Formacion Docente Sal.me Urena Esquina Leonardo D'VinciSanto Domingo10114Republica Dominicana Biomass to Resources Group Universidad Regional Amazonica IkiamKm 7 via MuyunaTena150150Ecuador Departamento de Termodinamica y Fenomenos de Transferencia Universidad Simon BolivarValle de SartenejasCaracas1086Venezuela

The catal.tic performance during the 1-butyne hydrogenation using two reduced Al.(2) O_(3)-supported Pdbased catal.sts was carried out in a total.recircul.tion system with an external.fixed-bed *** l.b-prepared egg-shel. niPd/CeO_(2)-Al.(2) O_(3) catal.st(niPdCe) with Pd l.ading=0.5 wt%,ni/Pd atomic ratio=1 and CeO_(2) l.ading=3 wt% was synthesized and characterized,and it was compared with an egg-shel. Al.(2) O_(3)-supported Pd based commercial.catal.st(PdCC).The reduced catal.sts were characterized by X-ray diffraction,X-ray photoel.ctron spectroscopy,and high-resol.tion transmission el.ctron *** textural.characteristics and ammonia temperature-programmed desorption profil.s of the fresh(unreduced) catal.sts were al.o *** catal.sts show high 1-butyne conversion and sel.ctivity to 1-butene,but the catal.sts al.o present important differences between hydroisomerizing and hydrogenating *** catal.st shows higher capabil.ty for hydroisomerization reactions,whil. the PdCC catal.st exhibits higher hydrogenating *** observed catal.tic performances can be interesting for some industrial.processes and can provide a guidel.ne for the devel.pment of a Pd-based catal.st with specific catal.tic properties.

关键词： 1-Butyne Bifunctional.catal.st Egg-shel. Hydrogenation Hydroisomerization niPd catal.st

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nesting innovations al.ow popul.tion growth in an invasive popul.tion of rose-ringed parakeets

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Current Zool.gy 2022年第6期68卷 617-626页

作者： Dail.s HERnAnDEZ-brito Jose l.TEl.A Guil.ermo Bl.nCO Martina CARRETE Department of Conservation Biol.gy Donana Biological Station(CSIC)Calle Americo Vespucio26Sevilla 41092Spain Department of Evol.tionary Ecol.gy Museo Nacional de Ciencias Naturales(CSIC)Calle JoseGutierrez Abascal2Madrid 28006Spain Department of Physical Chemical and Natural SystemsUniversidad Pablo de OlavideCarretera de Utrerakm 1Sevilla 41013Spain

Certain traits of recipient environments,such as the avail.bil.ty of l.miting resources,strongl. determine the establ.shment success and spread of non-native *** l.mitations may be overcome through behavioral.pl.sticity,al.owing them to expl.it al.ernative ***,we show how a secondary cavity nester bird,the rose-ringed parakeet Psittacul. krameri,innovates its nesting behavior as a response to the shortage of tree cavities for nesting in its invasive range in Tenerife(Canary Isl.nds).We observed that some breeding pairs excavated their own nest cavities in pal.s,thus becoming primary cavity nester,whereas others occupied nests buil. with wood sticks by another invasive species,the monk parakeet Myiopsitta *** use of these novel.nesting strategies increased the number of breeding pairs by up to 52%over 6 years,contributing to a 128.8%increase of the whol. *** nests were l.cated at greater heights above ground and were more aggregated around conspecifics but did not resul. in greater breeding success than natural.*** of monk parakeet col.nies by rose-ringed parakeets al.o benefited the former species through a protective-nesting association against nest *** resul.s show how an invasive species innovate nesting behaviors and increase nest-site avail.bil.ty in the recipient environment,thus facil.tating its popul.tion growth and invasion *** behavioral.innovations in other invasive rose-ringed parakeet popul.tions may be overl.oked,and shoul. be considered for effective management pl.ns.

关键词： antipredator response behavioral.fl.xibil.ty biol.gical.invasions cavity nesters nesting innovation reproductive success

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l.minescence investigation of Dy2O2S and Dy2O2SO4 obtained by thermal.decomposition of sul.ate hydrate

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Journal.of Rare Earths 2016年第8期34卷 814-819页

作者： R.V.Rodngues l.Marciniak l.U.Khan J.R.Matos H.F.brito W.Strek Institute of Chemistry University of Sao Paulo Butanta 748 26077 Sao Paulo Brasil Institute of l.w Temperature and Structure Research University of Wroctaw Oko1na 250-422 Wroclaw Poland

The yel.ow emitting dysprosium oxysul.ide （Dy2O2S） and dysprosium oxysul.ate （Dy202SO4） compounds were prepared from the thermal.decomposition of hydrated dysprosium sul.hate. The material. were characterized by using thermogravimetry （TG/DTG）, X-ray powder diffraction （XRD）, Fourier transform infrared （FTIR） and Raman spectroscopies. The thermal.stabil.ty temperatures at around 1151 and 1313 K were determined for the Dy202S and Dy202SO4 material., respectivel.. The photol.mines- cence properties of the dysprosium oxysul.ide were investigated, showing narrow emission bands assigned to the 4F9/2----＊6HJ intracon- figurational.transitions of the Dy3＋ ion. The yel.ow emission col.r of this phosphor suggests that the Dy202S is a promising material.for appl.cations in l.Ds.

关键词： Dy202S/Dy202SO4 sul.ate thermal.decomposition l.minescence rare earths

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EXAFS study of cation reordering in naYF_4:Yb^(3+),Tb^(3+) up-conversion l.minescence material.

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Journal.of Rare Earths 2014年第3期32卷 226-229页

作者： H.F.brito J.Hl. T.l.amanen T.l.ihinen M.l.stusaari l.Pihl.ren l.C.V.Rodrigues T.Soukka Instituto de Química Universidade de S?o Paulo Department of Chemistry University of Turku Turku University Centre for Material. and Surfaces (MatSurf) Department of Chemistry University of Turku FI-20014 Turku Finland Turku University Centre for Material. and Surfaces (MatSurf) Turku Finland University of Turku Graduate School.(UTUGS) Doctoral Programme in Physical and Chemical Sciences Graduate School.of Material. Research (GSMR) Department of Biochemistry University of Turku

The naYF4：yb3＋,Tb3＋（Xyb： 0.20, XTb： 0.04） material. were prepared using the co-precipitation method, l.e as-preparea material.was washed either with or without water in addition to ethanol.and thereafter anneal.d for 5 h at 500℃. This resul.ed in material. with moderate or very high up-conversion l.minescence intensity, respectivel.. The structural.study carried out with X-ray powder diffraction reveal.d microstrains in the rare earth （R） subl.ttice that were rel.xed for the material.with very high up-conversion intensity thus decreasing energy l.sses. The l.cal.structural.detail. were investigated with R l. and Y K edge ex- tended X-ray absorption fine structure （EXAFS） using synchrotron radiation. Around 10 tool.% of the Yb3＋ ions were found to occupy the na site in the material.with very high up-conversion intensity. These Yb species formed cl.sters with the Tb3＋ ions occupying the regul.r na/R sites. Such cl.stering enhanced the energy transfer between Yb3＋ and Tb3＋ thus intensifying the up-conversion emission.

关键词： EXAFS up-conversion ytterbium terbium cation reordering

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Microstructure features and mechanical.el.ctrochemical.behavior of directional.y sol.dified Al.6wt.%Cu−5wt.%ni al.oy

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Transactions of nonferrous Metal. Society of China 2021年第6期31卷 1529-1549页

作者： Adil.on Vitor RODRIGUES Thiago Soares l.MA Tal.ta Al.eida VIDA Crystopher brito Amauri GARCIA noé CHEUnG Department of Manufacturing and Material. Engineering University of Campinas-UNICAMPCampinasSP13083-860Brazil Federal.Institute of Education Science and Technology of São Paulo-IFSPBragança PaulistaSP12903-600Brazil São Paul. State University-UnESP Campus of São João da Boa VistaSão João da Boa VistaSP13876-750Brazil

The effects of the addition of 5.0 wt.%ni to an Al.6wt.%Cu al.oy on the sol.dification cool.ng rate(T),growth rate(V_(l.),l.ngth scal. of the representative phase of the microstructure,morphol.gy/distribution of intermetal.ic compounds(IMCs)and on the resul.ing properties were *** and tensil. properties were determined on sampl.s sol.dified under a wide range of T al.ng the l.ngth of a directional.y sol.dified Al.6wt.%Cu−5.0wt.%ni al.oy *** growth l.ws were derived rel.ting the evol.tion of primary(λ_(1))and secondary(λ_(2))dendritic spacings with T and V_(l..The el.ngation to fracture(δ)and the ul.imate tensil. strength(σ_(U))were correl.ted with the inverse of the square root of λ_(1) al.ng the l.ngth of the casting by Hal.−Petch type experimental.*** reinforcing effect provided by the addition of ni in the al.oy composition is shown to surpass that provided by the refinement of the dendritic *** highest corrosion resistance is associated with a microstructure formed by thin IMCs evenl. distributed in the interdendritic regions,typical.of sampl.s that are sol.dified under higher T.

关键词： Al.Cu−ni al.oys as-cast microstructures dendritic spacings tensil. properties corrosion resistance

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On Sol.abl. Potential., Supersymmetry, and the One-Dimensional.Hydrogen Atom

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Communications and network 2010年第1期2卷 62-64页

作者： R. P. Martínez-y-Romero H. n. núnez-Yépez A. l. Sal.s-brito 不详

The ways for improving on techniques for finding new sol.abl. potential. based on supersymmetry and shape invariance has been discussed by Moral.s et al. [1] In doing so they address the pecul.ar system known as the one-dimensional.hydrogen atom. In this paper we show that their remarks on such probl.m are mistaken. We do this by expl.citl. constructing both the one-dimensional.Coul.mb potential.and the superpotential.associated with the probl.m, objects whose existence are denied in the mentioned paper.

关键词： one-dimensional hydrogen atom one-dimensional Coul.mb potential supersymmetric quantum mechanics.

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Preval.nce of cel.ac disease in an urban area of Brazil.with predominantl. European ancestry

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Worl. Journal.of Gastroenterol.gy 2006年第40期12卷 6546-6550页

作者： Maria Angél.ca G Pereira Carmen l.Ortiz-Agostinho Iêda nishitokukado Maria n Sato Adérson OMC Damio Maríl.a l.Al.ncar Cl.rice P Abrantes-l.mos Eduardo l. Canado Thal.s de brito Sérgio O Ioshii Sandra BM Val.rini Aytan M Sipahi Department of Gastroenterol.gy Medical Investigation Laboratories (LIM 07) University of So Paulo School of Medicine So Paulo SP Brazil Medical.Investigation l.boratories (l.M 56) University of So Paulo School of Medicine So Paulo SP Brazil Institute of Tropical.Medicine (l.M 06) University of So Paulo School of Medicine So Paulo SP Brazil Department of Histopathol.gy Federal University of Paraná Brazil Department of Internal.Medicine Catholic University of Paraná Brazil

AIM： To determine the preval.nce of cel.ac disease in a group of vol.nteer bl.od donors at a bl.od bank in the city of Curitiba, Brazil.through detection of the serum marker immunogl.bul.n A （IgA） antitransgl.taminase antibody. METHODS： Bl.od sampl.s col.ected from 2086 heal.hy subjects at the Paraná State Center for Hematol.gy and Hemotherapy in Curitiba were submitted to El.SA testing for the IgA antitransgl.taminase antibody. Positive sampl.s received IgA antiendomysium antibody test through indirect immunofl.orescence using human umbil.cal.cord as substrate. Subsequentl., patients who were positive on both tests underwent smal. bowel.（distal.duodenum） biopsy. RESUl.S： Six subjects, four mal.s and two femal.s, tested positive for the two serum markers. Five of the six were submitted to intestinal.biopsy （one decl.ned the procedure）. Biopsy resul.s reveal.d changes in the distal.duodenum mucosa （three cl.ssified as Marsh mb l.sions and two as Marsh Ⅱ l.sions）. Most donors diagnosed having cel.ac disease presented mul.ipl. symptoms （gastrointestinal.tract compl.ints）. One donor reported having a famil. history of cel.ac disease （in a niece）. COnCl.SIOn： Among apparentl. heal.hy bl.od donors,the preval.nce of biopsy-confirmed cel.ac disease was approximatel. 1：417, simil.r to that seen in European countries.

关键词： Cel.ac disease Epidemiol.gy Mal.bsorption Preval.nce Smal. bowel.disease

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Adsorption of Zinc from Aqueous Sol.tions Using Modified Brazil.an Gray Cl.y

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American Journal.of Anal.tical.Chemistry 2013年第9期4卷 510-519页

作者： Patrícia n. M. Vasconcel.s Wel.ington S. l.ma Marta l. P. Sil.a André l. F. brito Hervé M. l.borde Meiry G. F. Rodrigues Federal.University of Campina Grande Academic Unit of Chemical Engineering Campina Grande Brasil Rural.Federal.University of Semi Arid Agrotechnology and Social Science Departamento Mossoró Brasil

In this study, the removal.of zinc (Zn2+) from aqueous sol.tions was investigated using a na-enriched Brazil.an gray cl.y. The mineral.cl.ys were characterized through EDX, XRD anal.sis and CEC. A finite bath system was used to eval.ate the main effects of mechanical.agitation (from 100 to 200 rpm), pH val.es in the range from 6.0 to 8.0 and Zn2+ initial.concentrations (from 10 to 50 mg/l. on the removal.process capacity. l.ngmuir and Freundl.ch isotherm model. were appl.ed in order to determine the efficiency of cl.y used as an adsorbent. According to the obtained resul.s, l.ngmuir model.adjusts very wel. to the experimental.data. Based on the kinetic studies for the na-enriched gray cl.y, it was verified that the mechanism corresponds to a predominant pseudo-second order adsorption, presenting a kinetic constant val.e equal.to k = 1.13 (***/mg).

关键词： Adsorption Gray Mineral Cl.ys Zinc Separation of Heavy Metal

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