ORIGINAL_ARTICLE
Aminothiophenol Furfural Self-assembled Gold Electrode Sensor
for Determination of Dopamine in Pharmaceutical Formulations
A new Schiff base 2-aminothiophenol furfural self assembled monolayer (SAM) has been fabricated on a bare gold electrode as a novel sensor for determination of dopamine. Electrochemical impedance spectroscopywas utilized to investigate the properties of the Au 2-aminothiophenol furfural self assembled monolayermodified electrode (Au ATF SAM-ME) using the [Fe(CN)6]3-/4- redox couple. The electrochemical behaviorof dopamine on the Au ATF SAM-ME was studied by cyclic voltammetry and differential pulse voltammetry,using phosphate buffer solution as supporting electrolyte. The ascorbic acid has no response on the modifiedself-assembly electrode. A calibration curve was obtained for dopamine in a linear range of 2.0 × 10-6 to 1.0 ×10-4 M. The detection limit for dopamine was found to be 3.0 × 10-7 M. The results indicated that the Au ATFSAM-ME could be employed for the determination of dopamine in pharmaceutical formulations.
http://jpe.miau.ac.ir/article_143_8e02ca41b92310df7ef5dd563d60adb1.pdf
2014-04-01
117
122
Dopamine
Ascorbic acid
Self-assembled monolayer
Gold electrode
ORIGINAL_ARTICLE
H2 Elimination and C-C Bond Cleavage of Propene: A
Theoretical Research
Propene dissociation channels were characterized by ab initio CCSD(T)/6-311++g(d,p) calculations. Inthis work the detailed mechanism of propene dissociation to C2H4+CH2, C2H2+H+CH3, C2H2+CH4 andC3H3+H2+H have been investigated. According to our calculations, ten fragments can be classified intofive dissociated channels. Our results point out that two mechanisms come into play in the H2 eliminationchannels. These channels are responsible for the formation of CH2CCH. The C-C bonds rupture occurthrough three different channels.
http://jpe.miau.ac.ir/article_144_f1ae17bfb33f80558960830a4a6c9767.pdf
2014-04-01
123
127
Propene
CCSD
H2 Elimination
ORIGINAL_ARTICLE
Thermodynamic Properties and Phase Equilibria for Liquid
Fluorine Using GMA Equation of State
Thermophysical properties of fluorine are interesting because of its applications in different areas of technologyand industry. The computations of thermodynamic properties were performed with the GMA equation of stateunder critical conditions. The present work reports calculations of density, volumetric, and thermodynamicproperties of liquid fluorine on extended ranges of pressure and temperature and the results show that GMAequation of state reproduces the experimental PVT data of fluorine within experimental errors throughout theliquid phase. The calculated results are different only a few percent from the experimental ones.
http://jpe.miau.ac.ir/article_145_e18977340d04aa1d65f6429def648803.pdf
2014-04-01
129
137
GMA Equation of state
liquid fluorine
Speed of sound
VLE prediction
ORIGINAL_ARTICLE
Thermodynamic Properties for Argon
An analytical equation of state is applied to calculate the thermodynamic properties for argon. Theequation of state is that of Song and Mason. It is based on a statistical-mechanical perturbation theory ofhard convex bodies and can be written as fifth-order polynomial in the density. There exist three temperaturedependentparameters: the second virial coefficient, an effective molecular volume, and a scaling factorfor the average contact pair distribution function of hard convex bodies. We used Lennard-Jones (12-6)potential for calculation temperature-dependent parameters. The equation of state has been applied tocalculate thermodynamic properties including the internal energy, the enthalpy, the entropy, the heat capacityat constant pressure, and the speed of sound for argon. The theoretical results are in good agreement withthe experimental data.
http://jpe.miau.ac.ir/article_146_35ab94b7f7c03ede9e7bda27a0648e03.pdf
2014-04-01
139
143
Thermodynamic
Argon
ORIGINAL_ARTICLE
Dynamic 1H NMR Study Around the Carbon–Carbon Double Bonds
and Carbon–Carbon Single Bonds in a Particular Phosphorous Ylide
and 2,5-Dihydro-5,5-Diaryl-2-Thio-1H-Imidazoles
Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. These phosphoranes undergo smooth intramolecular Wittig reaction followedby an electrocyclic ring opening to produce dialkyl (E)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)fumarates and 2,5-Dihydro-5,5-diaryl-2-thio-1H-imidazoles in good yields. Dynamiceffects were observed in the 1H NMR spectra of these compounds and were attributed to restrictedrotation around the Carbon-Carbon single bonds. Rotational energy barrier (ΔG#) for their interconversionprocess of rotational isomers equals to (68.2 and 71.7) ± 2 kJ mol-1.
http://jpe.miau.ac.ir/article_147_40788ce1983366397a3f1170562aaaf2.pdf
2014-04-01
145
148
Dynamic 1H NMR
Acetylenic ester
Restricted rotation
Triphenylphosphine
ORIGINAL_ARTICLE
Decrease of Electrical Conductivity Activation Energy of
Co-coated AISI 430 Alloy for the Application of SOFCs
The application of conductive coatings on ferritic stainless steel can decrease electrical conductivity. Theaim of this research was to investigate the electrical conductivity of cobalt coated AISI 430 ferritic stainlesssteel by pack cementation technique. Coated coupons were analyzed using scanning electron microscopy(SEM). Electrical conductivity of the coated substrates was measured as a function of temperature byoxidizing the samples from room temperature to 700 ºC. Also electrical conductivity has been measuredas a function of oxidation time during isothermal oxidation at 700 ºC. Results showed the increase oftemperature caused to the decrease of electrical conductivity and also, the coating layer converted to cobaltspinels during annealing in isothermal oxidation. The formation of MnCo2O4, CoCr2O4, CoFe2O4 and Co3O4spinels improved electrical conductivity activation energy of coated substrates (0.03 eV) compared touncoated substrates (0.039 eV).
http://jpe.miau.ac.ir/article_148_20a57326ac9253b60bbf62963196c0bb.pdf
2014-04-01
149
153
Cobalt
AISI 430
Electrical conductivity activation energy
Solid oxide fuel cell
ORIGINAL_ARTICLE
Modeling and Simulation a Catalytic Fixed Bed Reactor to
Produce Ethyl Benzene from Ethanol
Ethyl benzene used increasingly each year is the raw material of producing styrene monomer. This substanceis produced from benzene alkylation with ethylene or ethanol, depending on the availability and cost of rawmaterials. In this study benzene alkylation in the presence of ethanol in a catalytic fixed bed reactor inthree states of isotherm, adiabatic and non-isotherm-non-adiabatic is mathematically modeled with onedimensionalpseudo- homogeneous model; and then has been programmed with math lab software. Thereaction kinetics model is used in this study which comes from the experimental equations found by Mr.U.S Ridevi et al. in a zeolite catalyst impregnated with AlCl3 obtained in isotherm mode. The results of thissimulation in isotherm state are comparable with experimental data. The adiabatic and non-isotherm-nonadiabaticstates also show acceptable results. Furthermore, in this study the effect of various factors such asthe feed flow rate, substrate temperature, substrate density, fixed and variable heat capacity and viscosity offluid has been investigated.
http://jpe.miau.ac.ir/article_149_2964f35bc121f70c6af8c8afbe9658ea.pdf
2014-04-01
155
161
Fixed Bed Reactor
Ethyl Benzene
Modeling
Simulation
Ethanol
catalyst
ORIGINAL_ARTICLE
Temperature-Dependent Dispersion Coefficients of Alkali
Metals Using Equation of State
In this study, a temperature-dependent of the dispersion coefficients is calculated from equation state.The Lennard-Jones LJ (12-6-3) effective pair potential function and simple thermodynamic argumentwith the input PVT data of liquid metals are used to calculate the dispersion coefficients. The dispersioncoefficients ( , , ) 3 6 12 C C C are found to be a linear function of 1/T1+α , where T is the temperature and αis a constant and has different values for different dispersion coefficients. The law of corresponding statesbased on the reduced dispersion coefficients and reduced temperature is used to verify the validity of a LJ(12-6-3) potential function in describing the dispersion coefficients. By applying the dispersion coefficientsof alkali metals and potential function plots, the values of molecular parameters (å , ó , and, m r ) have beenobtained. The LJ (12-6-3) potential function conclusively predicts the best dispersion coefficients of thethree alkali metals (K, Rb, and Cs).
http://jpe.miau.ac.ir/article_150_c686e9ae4d6477f7ab0ff669dc5ea9a0.pdf
2014-04-01
163
169
Dispersion Coefficient
Equation of state
Alkali Metals