فهرست مطالب

  • Volume:2 Issue: 1, 2019
  • تاریخ انتشار: 1397/10/11
  • تعداد عناوین: 7
  • Esam Arafa Gomaa *, Mahmud Nabil Abdel Hady, Mahmoud Hanfy Mahmoud, Doaa Ahmed El Kot Pages 1-13
    Cyclic Voltammetry of Cobalt chloride with different concentrations was measured experimentally using DY2000 potentiostat. We used 0.1 M KCl as supporting electrolyte. Glassy carbon working electrode was used, purified and polished before use. The other two electrodes are platinum wire and Ag/AgCl electrode put in saturated KCl solution were used. The complex characters for the interaction of CoCl2 with Ceftriaxone disodium salt (Cefs) were studied with the use of different Ceftriaxone disodium salt (Cefs) concentrations at 298.65 K. The oxidation, reduction mechanisms and the stability constants of the complexes formed are discussed.  Scan rate and different kinetic parameters resulted from the interaction of CoCl2 with Ceftriaxone disodium salt (Cefs) were also evaluated and their values were discussed.
    Keywords: Cyclic Voltammetry, cobalt chloride, Ceftriaxone disodium salt (Cefs), Oxidation reduction mechanisms, Stability Constants, Kinetic parameters
  • MohammadHossein Fekri *, Azadeh Omrani, Saeed Jameh Bozorgi, Maryam Razavi Mehr Pages 14-20

    Schiff bases, an aldehyde- or ketone-like compounds in which the carbonyl group is replaced by an imine or azomethine, are some of the most widely used organic compounds. In this study, the quantum mechanics calculations were performed on M(Chel) where M=Ni(II) and Chel= BAE (bis-acetylacetoneethylenediimine), BBE=bis(benzoyl acetone)ethylenediimine, BFE= bis(1,1,1-triflouroacetylacetone) ethylenediimine and BCE = bis(3-chloroacetylacetone) ethylenediimine) ligands using Gaussian 03 and hartree-fock theory (HF) at B3LYP/6-311G level in the gas phase and solution phase. The polarized continuum model (PCM) is used to calculate salvation energies. After optimizing, various parameters such as electrode potentials, energy gap, chemical hardness, chemical potential and electrophilicity in solvent (DMSO) have been calculated. It was found to be planar and four coordinate. Reduction potentials toward a given M(II) according to the Schiff base ligands changed in the trend: BAE >BCE >BFE.

    Keywords: Schiff base, Gaussian 03, electrode potential, Energy gap, electrophilisity
  • Oyebanji Opeyemi, Hitler Louis, Chinanso Oparab, Oyebanji Funmilayo, Thomas Magu * Pages 21-44

    A remarkable source of renewable energy is the Dye- sensitized solar cells (DSCs). However, the major limitation of power conversion efficiency (PCE) of devices is their inability to produce electricity using photons from the near infrared (NIR) spectral region. Some Metal-free organic sensitizers make use of strong electron donating or withdrawing moieties to tune the optical band gap to allow the absorption of lower energy wavelengths in charge transfer systems while porphyrins and phthalocyanines compounds are used to shift the Soret and Q bands toward lower energy absorption. Various molecules are been synthesized to improve and increase the power conversion efficiency of the compounds. This study discusses the structure of these compounds, working principles and their derivatives as recent advances been carried out to improve the power efficiencies of the compounds.

    Keywords: Dye-sensitized solar cell, Porphyrin, Phthalocyanines
  • Marzieh Miranzadeh, MohammadZaman Kassaee *, Leila Sadeghi Pages 45-56

    Preservative capacity is measured for seventeen currently accessible Iranian made shampoo products. Upon purchase, bacterial counts show no trace of any microbial contamination. The shampoo bottles are distributed to seventeen female graduate students, residing at the time in different dormitories of Tarbiat Modares University (TMU). After 40 days, the allocated bottles are returned and their bacterial counts repeated, under the same conditions. To our surprise, no trace of any microbial contamination is observed. Three possibilities are considered. 1) The factory employed preservative(s) act very efficiently. 2) The shampoo component(s) are themselves bactericidal. 3) Existence of sanitary conditions and the absence of any microbial contaminants at TMU! Evidently, the third possibility is ruled out. The second choice is also discarded, because practically no significant antimicrobial activity is demonstrated by any of the four main ingredients of the shampoos including sodium lauryl ether sulfate (SLES), betaine, coconut fatty acid, and glycerin. Hence, the most likely possibility is the first one, since upon deliberate contamination of the seventeen brands; the factory employed preservatives [5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (KATHON CG)] prove highly bactericidal against four major contaminants: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and the methicillin-resistant Staphylococcus aureus (MRSA).

    Keywords: preservative, Iranian Shampoos, E. coli, S. aureus, P. aeruginosa, MRSA
  • Sakineh Alizadeh *, Tayyebeh Madrakian, Morteza Bahram Pages 57-72
    The present study aims to present a new convenient sensor for heavy metals, based on aggregation of citrate-capped- N, N' biphenyl hydrazine 1, 2 dicarbothioamide (PHCA) - modified- (AuNPs). This paper reports a procedure for sensitive and selective spectrophotometric methods for simultaneous determination of mercury (Hg22+) and cadmium (Cd2+). For this aim multivariate data including kinetic spectra of AuNPs were collected during aggregation process. The characterization of AuNPs was performed by transmission electron microscopy (TEM) and Infra-Red (IR) spectroscopy. Partial least square (PLS) regression as an efficient multivariate calibration method was employed to make a connection between the surface plasmon resonance (SPR) spectra of the generated AuNPs. The number of PLS latent variables was optimized by leave-one-out cross-validation utilizing prediction residual error sum of square (PRESS). The linear range was in the range of 3.33 × 10-5 - 3.33 × 10-6 mol L-1 and 2.0 × 10-5 - 1.0 × 10-6 mol L-1, the detection limit was 1.21×10-7 and 0.5 ×10-7 mol L-1 (n=5) for Hg22+and Cd2+, respectively. This method used successfully for simultaneous determination of Hg22+ and Cd2+ in West Azerbaijan regional waters namely Zarineh / Simineh rivers and Urmia Lake.
    Keywords: Cadmium, Mercury, Gold Nanoparticles, Simultaneous determination, multivariate analysis
  • Majid Momahed Heravi, Narges Karimi *, Samira Pooremami Pages 73-78
    We introduced a very simple, one-pot three component procedure for preparation of 2,4,5-triaryl-imidazoles from the reaction of benzyl, aldehydes and ammonium acetate, as ammonia source, catalyzed by Caro's acid-silica gel under Solvent –free condition.
    Keywords: MCR, Benzyl, Aldehydes, Ammonium acetate, Caro's acid-silica gel
  • Abdel Moneum M. Ahmed, Alaa E. Ali, Ahmed H. Ghazy* Pages 79-93

    In this study, the adsorption potential of activated carbon olive stone for removal of Ni(II) ions from wastewater has been investigated. The study involves batch type experiments to investigate the effect of initial concentration, adsorbent dose, agitation speed, contact time, temperature and pH of solution on adsorption process and the optimum conditions were evaluated. The adsorption process has fit pseudo-second order kinetic models. Langmuir and Freundlichadsorption isotherm models were applied to analyze adsorption data and both were found to be applicable to this adsorption process. Thermodynamic parameters, e.g., ΔGº, ΔSº and ΔHº of the on-going adsorption process have also been calculated and the sorption process was found to be endothermic. Finally, it can be seen that activated carbon olive stone was found to be more effective for the removal of Ni(II) from waste water than any adsorbent was used.

    Keywords: Wastewater, nickel, Activated carbon olive stone, Removal