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Corrosion Penetration and Crystal Structure of AA5022 in HCl Solution and Rare Earth Elements

Journal of materials Science & Technology 2005年第3期21卷 324-330页

作者： A.A.El-meligi S.H.Sanad A.A.Ismail 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 immersion corrosion tests in 1 mol/L HCl solution and different concentrations of rare earth elements (La3+), (Ce3+) and their combination, at different temperatures. X-ray diffraction (XRD) was used to examine the surface structure before and after immersion, and secondary electron detector (SED) was operated to study surface morphology. In 1 mol/L HCI solution the corrosion penetration increased with increasing temperature and immersion time. 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. mix3 (combination of La3+ and Ce3+) dramatically 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 combination 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 deformed 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 morphology shows that the roughness and voids of surface are increased.

关键词： Al-alloy Corrosion penetration Crystal structure XRD

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Development of Cd-doped Co Nanoparticles Encapsulated in Graphite Shell as Novel Electrode material for the Capacitive Deionization Technology

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Nano-micro Letters 2013年第4期5卷 303-313页

作者： Nasser a.m.barakat Khalil Abdelrazek Khalil Ahmad G.El-Deen Hak yong kim Organic materials and Fiber Engineering Department Chonbuk National University Chemical Engineering Department Minia University mechanical Engineering Department (NPST) King Saud University Dept of Bionano System Engineering College of Engineering Chonbuk National University

Because of the low energy requirement and the environmentally safe byproducts, the capacitive deionization water desalination technology has attracted the attention of many researchers. The important requirements for electrode materials are good electrical conductivity, high surface area, good chemical stability and high specific capacitance. In this study, metallic nanoparticles that are encapsulated in a graphite shell(Cd doped Co/C NPs) are introduced as the new electrode material for the capacitive deionization process because they have higher specific capacitance than the pristine carbonaceous materials. Cd doped Co/C NPs perform better than graphene and the activated carbon. The introduced nanoparticles were synthesized using a simple sol gel technique. A typical sol gel composed of cadmium acetate, cobalt acetate and poly(vinyl alcohol)was prepared based on the polycondensation property of the acetates. The physiochemical characterizations that were used confirmed that the drying, grinding and calcination in an Ar atmosphere 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 method to effectively use the encapsulated bimetallic nanostructures in the capacitive deionization technology.

关键词： Capacitive deionization Water desalination Bimetallic nanoparticles Specific capacitance

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

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Journal of materials 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 Abdelmoez mohamed H.El-Newehy Salem S.Al-Deyab Hak Yong Kim Organic materials and Fiber Engineering Department Chonbuk National University Chemical Engineering Department Faculty of EngineeringMinia University BioNanosystem Department Chonbuk National University Department of Chemistry College of ScienceKing Saud University

metal oxides have a higher chemical stability in comparison to metals,so they can be utilized as electrocatalysts if the activity could be *** the composition,the morphology of the nanostructures has a considerable impact on the electrocatalytic *** this work,zinc oxide nano branches-attached titanium dioxide nanofibers were investigated as an economic and stable catalyst for ethanol electrooxidation in the alkaline *** introduced material has been synthesized by electrospinning process followed by hydrothermal ***,electrospinning of colloidal solution consisting of titanium isopropoxide,poly（vinyl acetate） and zinc nanoparticles was performed to produce nanofibers embedding solid *** order to produce TiO2nanofibers containing ZnO nanoparticles,the obtained electrospun nanofiber mats were calcined in air at 600 °*** formed ZnO nanoparticles were exploited as seeds to outgrow ZnO branches around the TiO2nanofibers using the hydrothermal technique at sub-critical water conditions in the presence of zinc nitrate and bis-hexamethylene *** morphology of the final product,as well as the electrochemical measurements indicated that zinc nanoparticles content in the original electrospun nanofibers has a significant influence on the electrocatalytic activity as the best performance was observed with the nanofibers synthesized from electrospun solution containing 0.1 g Zn,and the corresponding current density was 37 mA/***,this study paves a way to titanium dioxide to be exploited to synthesize effective and stable metal oxide-based electrocatalysts.

关键词： Direct ethanol fuel cells Electrospinning Nanofibe

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Superconducting parameter determination for (Co0.5Zn0.5Fe2O4)x/Cu0.5Tl0.5-1223 composite

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Journal of Advanced Ceramics 2016年第3期5卷 210-218页

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

The addition of magnetic Co0.5Zn0.5Fe2O4 nanoparticles to the superconducting Cu0.5Tl0.5-1223 phase has been used to investigate the electrical resistivity behavior of the composite above the superconducting transition temperature Tc. This was studied according to the opening of spin gap and fluctuation conductivity. The results indicated that the pseudogap temperature (T*) and superconducting fluctuation temperature (Tscf) 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 antiferromagnetic fluctuation affected by magnetic nanoparticles. The excess-conductivity analysis showed four different fluctuation regions started from high temperature up to Tc, and they were denoted by short wave (sw), two-dimensional (2D), three-dimensional (3D), and critical (cr) fluctuations. The crossover temperature between 3D and 2D (T3D-2D) in the mean field region was decreased by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles, in accordance with the decrease in Tscf with x. The coherence length at 0 K along c-axis ξc(0), effective layer thickness of the 2D system d, and inter-layer coupling strength J were estimated as a function of Co0.5Zn0.5Fe2O4 nanoparticle addition. moreover, the thermodynamics, lower and upper critical magnetic fields, as well as critical current density have been calculated from the Ginzburg number NG. It was found that the low concentration of Co0.5Zn0.5Fe2O4 nanoparticles up to x = 0.08 wt% improves the superconducting parameters of Cu0.5Tl0.5-1223 phase. On the contrary, these parameters were deteriorated f

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

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Gamma induced changes in makrofol/CdSe nanocomposite films

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Chinese Physics B 2022年第9期31卷 547-553页

作者： Ali A.Alhazime m.mE.barakat Radiyah A.Bahareth E.m.mahrous Saad Aldawood S.Abd El Aal S.A.Nouh Physics Department Faculty of ScienceTaibah UniversityMedinaSaudi Arabia Department of Physics Faculty of ScienceTaibah UniversityYanbuSaudi Arabia Department of Physics Faculty of ScienceAlexandria UniversityAlexandriaEgypt Physics Department College of ScienceJeddah UniversityJeddahSaudi Arabia Department of Physics and Astronomy College of ScienceP.O.BOX 2455King Saud UniversitySaudi Arabia Center of Radiation Research and Technology Egyptian Atomic AuthorityNasr CityCairoEgypt Qassim University P.B.6644Buraidah 51452QassimSaudi Arabia Physics Department Faculty of ScienceAin Shams UniversityCairoEgypt

We applied an ex-situ casting procedure to prepare a nanocomposite(NCP)from makrofol polycarbonate(PC)and CdSe *** CdSe nanoparticles were prepared by a thermolysis procedure in the presence of N_(2) gas *** refinement of x-ray data illustrated that the CdSe adopts a cubic zinc blend structure of 6.057 A lattice parameter and 2 nm typical grain *** from the prepared NCP were exposed to γ dosages(20 kGy-250 kGy).The modifications induced in the NCP films owing to γ dosages have been ***γirradiation(50 kGy-250 kGy)causes crosslinks that reduce the optical bandgap from 4.15 eV to 3.81 eV,associated with an increase in dielectric parameters and refractive *** is attributed to an increase in the mass fraction of the disordered regions as specified by x-ray *** PC-CdSe NCP was found to have a reaction to color modification which makes it suitable for saleable reproduction on a printing press.

关键词： gamma nanocomposite x-ray dfraction UV spectra color changes

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mineralogy,Chemical Characteristics and Upgrading of Beach Ilmenite of the Top meter 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 mohamed I. mOUSTAFA Adel H. EI-AFANDY mohamed G. barakat Faculty of Science Zagazig University Egypt Engineering Colleges Northern Border University Saudi Arabia Nuclear materials Authority P. O. Box 530 Maadi Cairo Egypt

Egyptian beach ilmenite 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. microscopic study shows that the ilmenite occurs as fresh homogeneous black or heterogeneous multicoloured altered grains and exhibits three types （homogeneous, exsolved and altered） of ilmenite varieties. XRD data of ilmenite indicates their association with minor hematite and quartz, whereas leucoxene shows its association with Nb-rutUe, pseudorutile and hematite. 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 ilmenites, respectively. The density of fresh, altered ilmenite 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 magnetic susceptibility as a consequence of the leaching of iron. mass magnetic susceptibility reveals 97.6% of ilmenite and 92% of the altered form are obtained at 0.20 and 0.48 ampere. Fresh iimenite exhibits variable TiO2 （47.18%） and Fe2O3^T （46.10%） with minor mnO, mgO and Cr2O3 （1.22, 1.10 and 0.51%）. The altered ilmenite is higher in TiO2 （76.16%） and SiO2 （4.68%） and lower in Fe2O3^T （14.45%）, mnO, mgO and Cr2O3 （0.39, 0.52 and 0.11%） compared with the fresh form. Three concentrates of ilmenites （G1, G2 and G3） were prepared from crude ore using a Reading cross belt magnetic separator under different conditions, revealing a gradual increase of TiO2, SiO2, Al2O3 and CaO accompanied by a decrease of Fe2O3^T, mgO and Cr2O3 with repetition of the separation processes. Several ore dressing techniques were carried out to upgrade the iimenite concentrate.

关键词： Beach ilmenite mineralogy chemistry upgrading Northern Egypt

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Valence Stabilization of Polyvalent Uranium Ions in Presence of Some Organic Additives during Extended Gamma 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. Abdelhamid Department of Nuclear Safeguards and Physical Protection Nuclear and Radiological Control Authority Cairo Egypt Nuclear Chemistry Department Atomic Energy Authority Cairo Egypt

In gamma irradiated aqueous acidic uranium solutions, tetravalent uranium ions are easily oxidized while U(VI) ions remain unchanged. In general, valence change of polyvalent metallic ions during chemical reprocessing of spent nuclear fuel solutions can lead to undesirable effects under the influence of the existing gamma radiations. Consequently, studies on valence stabilization of Uranium ions during chemical treatment in strong gamma irradiation fields seem to be highly interesting. It has been reported before that some organic compounds proved to be effective in stabilizing the valence of Fe(II) ions during extended gamma irradiation of their acidic solutions. In the present work, valence stabilization of Uranium ions in acidic solutions in presence of different classes of organic compounds has been studied. The results showed that in case of U(IV), methanol or formic 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 formed U(IV) was protected as follows: formic acid or methanol 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 completely consumed.

关键词： Valence Stabilization Uranium(IV) Ions Radiolysis Protective Effect Competitive Reactions

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Valence Stabilization of Fe(II) Ions during Extended Gamma 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 Hamid Nuclear and Radiological Control Authority Cairo Egypt Hot Labs Center Atomic Energy Authority Cairo Egypt

Valence stabilization of polyvalent ions in acidic solutions during gamma irradiation is an important issue in nuclear aqueous chemical technology. Radiolysis and self irradiation problems encountered during chemical reprocessing of nuclear fuel or during chemical separation of transuranium elements or fission products are extremely important. Consequently studies on valence stabilization of polyvalent ions in strong gamma irradiation fields are very useful. In our previous publications, the valence stabilization of Fe(II) ions in acidic solutions during continuous gamma irradiation was achieved by using an inorganic compound;such as sodium sulfite, or some organic additives such as aliphatic alcohols, aldehyds or acids prior to irradiation. It was found that the efficiency of valence stabilization depends on the amount and chemical structure of the added compounds. In the present work, valence stabilization of divalent iron during gamma irradiation was studied in presence of some organic additives, belonging to some other classes of organic compounds such as Phenol (aromatic alcohol), Acetone (aliphatic ketone), 4-Aminopyridine (heterocyclic amino compound) and Hydrazine hydrate (aliphatic amino compound) to complement our previous studies. The results showed that valence stabilization of Fe(II) in presence of these compounds depends also on the amount and chemical structure of the additive used. Some interaction mechanisms have been proposed.

关键词： Water Radiolysis Valence Stabilization Extended Gamma Irradiation Competitive Reactions Polyvalent Ions Protective Effects

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One-pot activation and pyrolysis of moroccan Gelidium sesquipedale red macroalgae residue:production of an efficient adsorbent biochar

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Biochar 2019年第4期1卷 401-412页

作者： Saida Tayibi Florian monlau Nour-elhouda Fayoud Abdallah.Oukarroum Youssef Zeroual Hassan Hannache Abdellatif barakat IATE Montpellier SupAgroINRAEUniversite de MontpellierMontpellierFrance mohammed VI Polytechnic University(Um6P) BenguerirMorocco APESA Pôle ValorisationCap EcologiaLescarFrance LImAT Facultédes Sciences Ben M’SikUniversitéHassan II de CasablancaCasablancaMorocco Situation Innovation OCP GroupComplexe industriel Jorf LasfarEl

One-pot chemical activation and pyrolysis process was developed for biochar production from red macroalgae residue of Gelidium *** macroalgae residue was activated by various catalysts(KOH,NaOH,H_(3)PO_(4),and CH_(4)ON_(2))with the two concentrations(2.5 wt%and 5 wt%)using a pulverization system followed by slow pyrolysis at 500℃.The activated biochars showed a porous morphology with an increase of water holding capacity compared to the unactivated *** properties of activated biochar observed by further characterization(i.e.,FTIR,SEm,TGA)revealed their feasibility to be used as an *** results of adsorption experiment confirmed that adsorption was dependent not only on the surface area but also on the surface charge,and functional *** sorption performance of activated biochars(AcBC),in terms of the adsorption of methylene blue,was comparable to commercial activated charcoal(Norit^(■)).NaOH(2.5 wt%)-activated biochar had the removal efficiency of 87%versus 97%for commercial activated charcoal.

关键词： Red macroalgae residue Chemical activation Slow pyrolysis Adsorption

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Effect of <i>Trichoderma harzianum</i>in Combination with Fungicides in Controlling Gray mould Disease (<i>Botrytis cinerea</i>) of Strawberry

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American Journal of Plant Sciences 2017年第4期8卷 651-665页

作者： Radwan m. barakat mohammad I. Al-masri Plant Protection Research Center Faculty of Agriculture Hebron University Hebron Palestine

The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.

关键词： Fungicides Trichoderma harzianum Botrytis cinerea Gray mould Strawberry

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