فهرست مطالب

new Chemistry - Volume:6 Issue:3, 2019
  • Volume:6 Issue:3, 2019
  • تاریخ انتشار: 1398/06/10
  • تعداد عناوین: 6
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  • Ehsan Darouneh *, Tahereh Pirhooshyaran, Hashem Shalagheh Pages 151-155
    The objective of this research was the economic analysis of two different methods for the clarification of sugarcane juice. The first method was the method of using 700 ppm of CaO (final pH=7.9) and 1 ppm of Separan flocculant which previouly was being used. The other method was using 500 ppm of CaO (final pH=7.4) and 3 ppm of Separan flocculant. This study was carried out on an industrial scale in the Karoon sugar industry in south west of Iran. The results showed that increasing the amount of Separan and reducing the amount of lime directly increases the purification and the brix of the juice besides reducing the amount of lime precipitation in the evaporators. Economic analysis of the total process showed that the second method of clarification was 5 % more economical.
    Keywords: Clarification, Separan, lime, Economic Analysis, Sugarcane
  • S. Sepehr Uroomiye * Pages 156-162

    In this study, paraphenylenediamine was first bonded to the fullerene and was optimized geometrically by Using the quantum chemistry methods. paraphenylenediamine was examined in the isolated state and in the fullerene-bonded state via carbon atoms. In the theoretical research, the simulation was done by the Gauss View software. Then, the bonding orbital calculation was done by using the NBO method. All the calculations were performed by the Hartree-Fock method in the 6-31G* (HF/6-31G*) level of theory and the Gauss View and Gaussian 2003 software in the gas phase. The contribution of p-orbital in the N-H bond, the natural charge and the number of valence electrons on the nitrogen atom at the site bonding to the fullerene were investigated in the isolated state and in the fullerene-bonded state. All evidence showed a decrease in the basicity of the nitrogen atom at the site of bonding to the fullerene.

    Keywords: Fullerene, the participation of p-orbital, NBO, Hartree-Fock
  • Asadollah Beiraghi *, Ali Reza Shirkhani, Azim Ziyaei Halimehjani Pages 163-177
    In this study a cloud-point extraction process using non-ionic surfactant Triton X-114 for extraction of mercury (II) from aqueous solutions was developed. The method is based on the complex formation of Hg (II) with benzyl (pyridin-2-yl) methylcarbamodithioate at pH 5.5. After preconcentration and dilution of the surfactant-rich phase, the enriched analyte was determined by spectrophotometer. The effects of different parameters such as concentration of surfactant, electrolyte, temperature and pH on the cloud point extraction were studied in detail and a set of optimum conditions were established. Under the optimum conditions, the calibration graph was linear in the range of 0.25–3 µg mL-1 with detection limit of 0.02 µg mL-1. The precision (R.S.D. %) for 1 µg mL-1 of Hg (II) was 1.6% (n=5) and the preconcentration factor was found to be 20. Under the presence of foreign ions, no significant interference was observed. Finally, the proposed method was applied successfully for the determination of Hg (II) in real water samples.
    Keywords: Mercury, Cloud point extraction, Spectrophotometry, benzyl (pyridin-2-yl) methylcarbamodithioate, Triton X-114
  • Aram Ghaempanah *, Mahdi Babaie, Nader Mosavari Pages 178-189
    Thiouracilis a historically relevant anti-thyroid preparation. Because of its structure you can find it in various chemical reactions differently. In this study, the reaction of Thiouracil with Chloroacetic acid and the formation of their additive products has been investigated. This reaction is aconcerted process, and it has not been determined yet by exhaustive mechanisms. From the potential energy profile, two possible mechanisms as well as two NH bonds dissociations are examined. Density Functional Theory (DFT) was used to compare these mechanisms. Calculation results for comparing these two pass ways were indicated byB3LYP/6-311g (d,p) levels of theory. The activation energies to 2-(6-oxo-1,6-dihydropyrimidin-2-ylthio) acetic acid and 2-(4-oxo-1,4-dihydropyrimidin-2-ylthio) acetic acid formation were obtained 55.78 and 72.9 kcal.mol-1, respectively. These calculations were also carried out for ethyl and methyl Thiouracil derivatives. The calculation results indicate that removal of hydrogen from nitrogen to sulfur group at the ortho position is more favorable
    Keywords: Thiouracil, Chloroacetic acid, DFT, B3LYP, Activation Energy
  • Azita Salimian * Pages 190-197
    Vanadium oxide nanotubes belong to inorganic nanotubes. One inorganic nanotubes (WS2) synthesized in 1992.Vanadium oxide nanotubes discovared by spahr in 1998.Vanadium oxide nanotubes are used in chemical, bio, electronics and catalysts industry. Many applications of these nanotubes have not yet been discovered. Especially when these nanotubes are doped with different elements. The structure of these nanotubes is flexible. This makes it possible to explore different ideas. In this research study zirconium – doped vanadium oxide nanotubes (VONTs) with different percentages were synthesized. Zr-doped VONTs were performed by hydrothermal method. Zr-VONTs prepared (0, 2, 10, 20, 30, 50 and 60) %wt. The structure and morphology of the nanotubes were investigated by x- ray diffraction (XRD), scanning electron microscopy (SEM). The results showed that zirconium 2%wt doped VONTs complately but in others amount in addition doped, was forming zirconium oxide phase. Also with increase percent of doping Zr into vanadium oxide nanotubes were formed monoclinic structure of ZrO2.The increase of doping level of the ZrO2 phase leads to change interlayer distances.
    Keywords: Vanadium oxide nanotubes (VONTs), Zirconium (Zr), Hydrothermal, Doped
  • NEDA HAJIZADEH * Pages 198-214
    In this research, a coated graphite electrode was constructed for determination of Mg2+ in pharmaceutical supplements. The designed sensor demonstrates an ideal Nernstian slope (30.1 mV. Decade-1) over a wide concentration range (1×10-6- 1×10-1 Mol L-1). The selectivity of the sensor was evaluated over 16 different cations by matched potential method and no serious interference was observed from them. The designed electrode could also be used in partially non aqueous mediums up to the presence of 20% of organic solvents without any tangible alteration in Nernstian slope and linearity domain. The response time and life span of the proposed electrode were 20s and 2 months respectively. The function of the electrode was inspected in solutions with different pH value and also as an indicator electrode in potentiometric titration with EDTA.
    Keywords: Magnesium, Potentiometry, Ion selective electrode, Risperidone