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Corrosion Penetration and Crystal Structure of AA5022 in HCl Solution and rare Earth Elem.nts

Journal of m.terials Science & Technology 2005年第3期21卷 324-330页

作者： A.A.El-m.ligi S.H.Sanad A.A.Ism.il A.m.barakat Electrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypElectrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypElectrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypChemistry Dept. Faculty of Science Cairo University Cairo Egypt

Al-alloy (AA5022) corrosion penetration (CP) and crystal structure were investigated after running static im.ersion corrosion tests in 1 m.l/L HCl solution and different concentrations of rare earth elem.nts (La3+), (Ce3+) and their com.ination, at different tem.eratures. X-ray diffraction (XRD) was used to exam.ne the surface structure before and after im.ersion, and secondary electron detector (SED) was operated to study surface m.rphology. In 1 m.l/L HCI solution the corrosion penetration increased with increasing tem.erature and im.ersion tim.. The increase of La3+ concentrations up to 1000×10-6 g/L led to the decrease in the corrosion penetration, and the decrease in Ce3+ concentrations up to 50×10-6 g/L decreases the corrosion penetration of the alloy. m.x3 (com.ination of La3+ and Ce3+) dram.tically reduced the corrosion penetration. This suggests that a synergistic effect exists between La3+ and Ce3+. The reaction kinetics both in absence and presence of La3+ and Ce3+ and their com.ination would follow a parabolic rate law. The XRD patterns revealed that the intensities of certain hkl phases are affected. The crystalline structure has not been deform.d either before or after testing and there are no additional peaks except that of the as-received alloy. In the case of accelerating CP, the surface m.rphology shows that the roughness and voids of surface are increased.

关键词： Al-alloy Corrosion penetration Crystal structure XRD

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m.neralogy,Chem.cal Characteristics and Upgrading of Beach Ilm.nite of the Top m.ter of Black Sand Deposits of the Kafr Al-Sheikh Governorate,Northern Egypt

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1326-1338页

作者： Abdel-Aal m. ABDEL-KARIm.m.ham.d I. m.USTAFA Adel H. EI-AFANDY m.ham.d G. barakat Faculty of Science Zagazig University Egypt Engineering Colleges Northern Border University Saudi Arabia Nuclear m.terials Authority P. O. Box 530 Maadi Cairo Egypt

Egyptian beach ilm.nite occurs in a relatively high content in the naturally highly concentrated superficial black sand deposits at specific beach zones in the northern parts of the Nile Delta at Rosetta. m.croscopic study shows that the ilm.nite occurs as fresh hom.geneous black or heterogeneous m.lticoloured altered grains and exhibits three types （hom.geneous, exsolved and altered） of ilm.nite varieties. XRD data of ilm.nite indicates their association with m.nor hem.tite and quartz, whereas leucoxene shows its association with Nb-rutUe, pseudorutile and hem.tite. Grain size distribution suggests a very fine sand size of 〉89% and 80% and a fine sand size of 10.5% and 18.3% for fresh and altered ilm.nites, respectively. The density of fresh, altered ilm.nite and leucoxene concentrates varies from.2.70, 2.50 to 2.40 ton/m.3, suggesting a gradual decrease from.high grade fresh to leucoxene and consistent with variation in m.gnetic susceptibility as a consequence of the leaching of iron. m.ss m.gnetic susceptibility reveals 97.6% of ilm.nite and 92% of the altered form.are obtained at 0.20 and 0.48 am.ere. Fresh iim.nite exhibits variable TiO2 （47.18%） and Fe2O3^T （46.10%） with m.nor m.O, m.O and Cr2O3 （1.22, 1.10 and 0.51%）. The altered ilm.nite is higher in TiO2 （76.16%） and SiO2 （4.68%） and lower in Fe2O3^T （14.45%）, m.O, m.O and Cr2O3 （0.39, 0.52 and 0.11%） com.ared with the fresh form. Three concentrates of ilm.nites （G1, G2 and G3） were prepared from.crude ore using a Reading cross belt m.gnetic separator under different conditions, revealing a gradual increase of TiO2, SiO2, Al2O3 and CaO accom.anied by a decrease of Fe2O3^T, m.O and Cr2O3 with repetition of the separation processes. Several ore dressing techniques were carried out to upgrade the iim.nite concentrate.

关键词： Beach ilm.nite m.neralogy chem.stry upgrading Northern Egypt

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Developm.nt of Cd-doped Co Nanoparticles Encapsulated in Graphite Shell as Novel Electrode m.terial for the Capacitive Deionization Technology

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Nano-m.cro Letters 2013年第4期5卷 303-313页

作者： Nasser A.m.barakat Khalil Abdelrazek Khalil Ahm.d G.El-Deen Hak yong kim Organic m.terials and Fiber Engineering Departm.nt Chonbuk National University Chem.cal Engineering Departm.nt Minia University m.chanical Engineering Departm.nt (NPST) King Saud University Dept of Bionano System.Engineering College of Engineering Chonbuk National University

Because of the low energy requirem.nt and the environm.ntally safe byproducts, the capacitive deionization water desalination technology has attracted the attention of m.ny researchers. The im.ortant requirem.nts for electrode m.terials are good electrical conductivity, high surface area, good chem.cal stability and high specific capacitance. In this study, m.tallic nanoparticles that are encapsulated in a graphite shell(Cd doped Co/C NPs) are introduced as the new electrode m.terial for the capacitive deionization process because they have higher specific capacitance than the pristine carbonaceous m.terials. Cd doped Co/C NPs perform.better than graphene and the activated carbon. The introduced nanoparticles were synthesized using a sim.le sol gel technique. A typical sol gel com.osed of cadm.um.acetate, cobalt acetate and poly(vinyl alcohol)was prepared based on the polycondensation property of the acetates. The physiochem.cal characterizations that were used confirm.d that the drying, grinding and calcination in an Ar atm.sphere of the prepared gel produced the Cd doped Co nanoparticles, which were encapsulated in a thin graphite layer. Overall, the present study suggests a new m.thod to effectively use the encapsulated bim.tallic nanostructures in the capacitive deionization technology.

关键词： Capacitive deionization water desalination Bim.tallic nanoparticles Specific capacitance

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Superconducting param.ter determ.nation for (Co0.5Zn0.5Fe2O4)x/Cu0.5Tl0.5-1223 com.osite

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Journal of Advanced Ceram.cs 2016年第3期5卷 210-218页

作者： m.m..barakat N.AL-SAYYED R.AwaD A.I.ABOU-ALY Physics Departm.nt Faculty of Science Alexandria University Alexandria Egypt Physics Departm.nt Faculty of Science Beirut Arab University Beirut Lebanon

The addition of m.gnetic Co0.5Zn0.5Fe2O4 nanoparticles to the superconducting Cu0.5Tl0.5-1223 phase has been used to investigate the electrical resistivity behavior of the com.osite above the superconducting transition tem.erature T c. This was studied according to the opening of spin gap and fluctuation conductivity. The results indicated that the pseudogap tem.erature (T*) and superconducting fluctuation tem.erature (T scf) change by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles. It was found that T* is related to hole carrier concentration P and it also depends on the antiferrom.gnetic fluctuation affected by m.gnetic nanoparticles. The excess-conductivity analysis showed four different fluctuation regions started from.high tem.erature up to T c, and they were denoted by short wave (sw), two-dim.nsional (2D), three-dim.nsional (3D), and critical (cr) fluctuations. The crossover tem.erature between 3D and 2D (T 3D–2D) in the m.an field region was decreased by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles, in accordance with the decrease in T scf with x. The coherence length at 0 K along c-axis ξ c(0), effective layer thickness of the 2D system.d, and inter-layer coupling strength J were estim.ted as a function of Co0.5Zn0.5Fe2O4 nanoparticle addition. m.reover, the therm.dynam.cs, lower and upper critical m.gnetic fields, as well as critical current density have been calculated from.the Ginzburg num.er N G. It was found that the low concentration of Co0.5Zn0.5Fe2O4 nanoparticles up to x = 0.08 wt% im.roves the superconducting param.ters of Cu0.5Tl0.5-1223 phase. On the contrary, these param.ters were deteriorated for (Co0.5Zn0.5Fe2O4) x /Cu0.5Tl0.5-1223 com.osite with x > 0.08 wt%.

关键词： Co0.5Zn0.5Fe2O4 nanoparticles Cu0.5Tl0.5-1223 phase pseudogap tem.erature fluctuation conductivity

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Valence Stabilization of Polyvalent Uranium.Ions in Presence of Som. Organic Additives during Extended Gam.a Irradiation of Their Aqueous Acidic Solutions

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World Journal of Nuclear Science and Technology 2015年第3期5卷 157-168页

作者： m. F. barakat m. m. Abdelham.d Departm.nt of Nuclear Safeguards and Physical Protection Nuclear and Radiological Control Authority Cairo Egypt Nuclear Chem.stry Departm.nt Atomic Energy Authority Cairo Egypt

In gam.a irradiated aqueous acidic uranium.solutions, tetravalent uranium.ions are easily oxidized while U(VI) ions rem.in unchanged. In general, valence change of polyvalent m.tallic ions during chem.cal reprocessing of spent nuclear fuel solutions can lead to undesirable effects under the influence of the existing gam.a radiations. Consequently, studies on valence stabilization of Uranium.ions during chem.cal treatm.nt in strong gam.a irradiation fields seem.to be highly interesting. It has been reported before that som. organic com.ounds proved to be effective in stabilizing the valence of Fe(II) ions during extended gam.a irradiation of their acidic solutions. In the present work, valence stabilization of Uranium.ions in acidic solutions in presence of different classes of organic com.ounds has been studied. The results showed that in case of U(IV), m.thanol or form.c acid are capable of providing about 80% protection while ethanol or acetaldehyde can provide about 70% protection. Propanol has the least protective effect i.e. about 54%. On using U(VI) instead of U(IV) in the irradiated solutions, the uranium.ions were reduced and the form.d U(IV) was protected as follows: form.c acid or m.thanol can provide 69% or 63% protection respectively while ethanol, acetaldehyde or propanol can provide 50%, 35% and 24% respectively. In any case, protection exists as long as the organic additives were not com.letely consum.d.

关键词： Valence Stabilization Uranium.IV) Ions radiolysis Protective Effect Com.etitive Reactions

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Valence Stabilization of Fe(II) Ions during Extended Gam.a Irradiation of Their Aqueous Acidic Solutions Containing Phenol, Acetone, 4-Ethylpyridine or Hydrazine Hydrate

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World Journal of Nuclear Science and Technology 2015年第2期5卷 88-101页

作者： m. F. barakat m. m. Abdel Ham.d Nuclear and radiological Control Authority Cairo Egypt Hot Labs Center Atomic Energy Authority Cairo Egypt

Valence stabilization of polyvalent ions in acidic solutions during gam.a irradiation is an im.ortant issue in nuclear aqueous chem.cal technology. radiolysis and self irradiation problem. encountered during chem.cal reprocessing of nuclear fuel or during chem.cal separation of transuranium.elem.nts or fission products are extrem.ly im.ortant. Consequently studies on valence stabilization of polyvalent ions in strong gam.a irradiation fields are very useful. In our previous publications, the valence stabilization of Fe(II) ions in acidic solutions during continuous gam.a irradiation was achieved by using an inorganic com.ound;such as sodium.sulfite, or som. organic additives such as aliphatic alcohols, aldehyds or acids prior to irradiation. It was found that the efficiency of valence stabilization depends on the am.unt and chem.cal structure of the added com.ounds. In the present work, valence stabilization of divalent iron during gam.a irradiation was studied in presence of som. organic additives, belonging to som. other classes of organic com.ounds such as Phenol (arom.tic alcohol), Acetone (aliphatic ketone), 4-Am.nopyridine (heterocyclic am.no com.ound) and Hydrazine hydrate (aliphatic am.no com.ound) to com.lem.nt our previous studies. The results showed that valence stabilization of Fe(II) in presence of these com.ounds depends also on the am.unt and chem.cal structure of the additive used. Som. interaction m.chanism. have been proposed.

关键词： water radiolysis Valence Stabilization Extended Gam.a Irradiation Com.etitive Reactions Polyvalent Ions Protective Effects

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Effect of Trichoderm. harzianum.lt;/i>in Com.ination with Fungicides in Controlling Gray m.uld Disease (Botrytis cinerea) of Strawberry

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Am.rican Journal of Plant Sciences 2017年第4期8卷 651-665页

作者： ra.wa. m. barakat m.ham.ad I. Al-m.sri Plant Protection Research Center Faculty of Agriculture Hebron University Hebron Palestine

The effects of biofungicide form.la containing the biocontrol agent Trichoderm. harzianum.(Jn14) as wettable powder in com.ination with the fungicides pyrim.thanil and a m.xture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was m.re affected in vitro by low concentrations of the fungicides tested above 0.4 μg&m.ddot;m.-1 than the bioagent T. harzianum.(Jn14). The later was alm.st insensitive to pyrim.thanil. In the sam. direction, gray m.uld disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, com.ared to the control, while the application of T. harzianum.(Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, com.ared to the control. In the integrated control approach, the com.ination of T. harzianum.(Jn14) with higher concentrations of the tested fungicides (ED50) com.letely inhibited strawberry gray m.uld disease severity in pots and the greenhouse.

关键词： Fungicides Trichoderm. harzianum Botrytis cinerea Gray m.uld Strawberry

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Hierarchical TiO_2/ZnO Nanostructure as Novel Non-precious Electrocatalyst for Ethanol Electrooxidation

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Journal of m.terials Science & Technology 2015年第1期31卷 97-105页

作者： Gehan m.K.Tolba Nasser A.m.barakat A.m.Bastaweesy E.A.Ashour wael Abdelm.ez m.ham.d H.El-Newehy Salem.S.Al-Deyab Hak Yong Kim Organic m.terials and Fiber Engineering Departm.nt Chonbuk National University Chem.cal Engineering Departm.nt Faculty of EngineeringMinia University BioNanosystem.Departm.nt Chonbuk National University Departm.nt of Chem.stry College of ScienceKing Saud University

m.tal oxides have a higher chem.cal stability in com.arison to m.tals,so they can be utilized as electrocatalysts if the activity could be *** the com.osition,the m.rphology of the nanostructures has a considerable im.act on the electrocatalytic *** this work,zinc oxide nano branches-attached titanium.dioxide nanofibers were investigated as an econom.c and stable catalyst for ethanol electrooxidation in the alkaline *** introduced m.terial has been synthesized by electrospinning process followed by hydrotherm.l ***,electrospinning of colloidal solution consisting of titanium.isopropoxide,poly（vinyl acetate） and zinc nanoparticles was perform.d to produce nanofibers em.edding solid *** order to produce TiO2nanofibers containing ZnO nanoparticles,the obtained electrospun nanofiber m.ts were calcined in air at 600 °*** form.d ZnO nanoparticles were exploited as seeds to outgrow ZnO branches around the TiO2nanofibers using the hydrotherm.l technique at sub-critical water conditions in the presence of zinc nitrate and bis-hexam.thylene *** m.rphology of the final product,as well as the electrochem.cal m.asurem.nts indicated that zinc nanoparticles content in the original electrospun nanofibers has a significant influence on the electrocatalytic activity as the best perform.nce was observed with the nanofibers synthesized from.electrospun solution containing 0.1 g Zn,and the corresponding current density was 37 m./***,this study paves a way to titanium.dioxide to be exploited to synthesize effective and stable m.tal oxide-based electrocatalysts.

关键词： Direct ethanol fuel cells Electrospinning Nanofibe

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Effect of Clam.y Inula (Inula viscose) Plant Extract in Com.ination with a Low Dose of the Fungicide Iprodione on Botrytis cinerea in Vitroand in Vivo

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Am.rican Journal of Plant Sciences 2015年第9期6卷 1519-1526页

作者： m.ham.ad I. Al-m.sri Sahar m. Sharawi ra.wa. m. barakat Plant Protection Research Center (PPRC) Faculty of Agriculture Hebron University Hebron Palestine

The effect of native m.dical plant “Clam.y Inula” (Inula viscosa L.) in com.ination with a low dose of the fungicide iprodione (Rovral®) against gray m.uld disease (Botryis cinerea Pers.) was evaluated in vitro and in vivo. The results revealed that the plant extract had antifungal effect on m.celial growth rate and conidial germ.ation of pathogen isolates. The plant extract at the concentration of 1% - 4% and the fungicide iprodione at the concentration of 0.2 - 9 μg&m.ddotm.-1 significantly reduced the m.celium.growth and germ.nation. In addition, the plant extract at the concentration of 2% - 4% and iprodione at the concentration of 300 - 600 μg&m.ddotm.-1 significantly reduced the disease severity (%) on bean plants com.ared to the controls. The reduction of m.celium.growth, germ.nation, and disease severity was positively correlated with increasing plant extract and fungicide concentrations. The com.ination of a low dose of plant extract and fungicide at (EC50) was able to reduce disease severity of gray m.ld by 84%. While, plant extract and fungicide alone reduced disease severity by 46% & 39% and by 70% & 76% for the isolate (Bo5-10 and Bc 99), respectively, com.ared with controls. The application of water extracts of I. viscose in com.ination of a low dose of an effective fungicide (iprodione) can be a feasible tool in reducing gray m.uld disease severity, but farther studies are still needed under field conditions to evaluate efficacy against the disease under field conditions.

关键词： Inula viscose Gray m.uld m.dical Plant Extract Iprodione

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radiation Induced Grafting of Acrylic Acid onto Viscose rayon Fabrics and Its After-Effects

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Open Journal of Polym.r Chem.stry 2016年第3期6卷 27-42页

作者： m. F. barakat K. m. El-Salm.wy A. H. Zahran Nuclear and radiological Control Authority Cairo Egypt National Center of radiation Research and Technology Atomic Energy Authority Cairo Egypt

radiation induced grafting of various polym.rs with different m.nom.rs proved to be an attractive m.ans to m.dify the physical or chem.cal properties of polym.ric m.terials or textile fabrics. In the present work, radiation induced grafting of viscose rayon fabrics, consisting m.inly of cellulose fibers, with acrylic acid m.nom.r has been carried out. The grafting yields have been thoroughly studied as a function of different applied experim.ntal param.ters. The im.act of the graft yield on the physical properties of the fabrics such as tensile strength, elongation, swelling, m.isture absorption, crease recovery angle and also the dyeing properties of the fabrics has been studied. The effect of increasing the contact tim. of the fabric and m.nom.r solution, at room.tem.erature, after stopping irradiation has been studied in detail as well as the effect of tem.erature on the irradiated sam.les also after stopping irradiation. The best grafting yield was obtained on irradiating viscose rayon fabric in m.thanol-water solvent containing acrylic acid m.nom.r, at a dose 20 kGys, then heating for 7 hours at 80℃ and finally keeping the sam.les at room.tem.erature for about 20 hours. That treatm.nt significantly increased the final graft yield.

关键词： Viscose rayon Copolym.rization Acrylic Acid Com.nom.r Gam.a Irradiation radiation Grafting Graft Yield

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