Iranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Sensing Performance of Sc-doped B12N12 Nanocage for Detecting Toxic Cyanogen Gas: A Computational Study3153321414210.22036/pcr.2016.14142ENMohammad SolimannejadArak Universityhttps://orcid.org/00Saeedeh KamalinahadArak UniversityEhsan ShakerzadehShahid Chamran UniversityJournal Article20160206Adsorption of cyanogen molecule on the surface of pristine and Sc-doped B<sub>12</sub>N<sub>12</sub> nanocage is scrutinized using at DFT calculations to investigating its potential as chemical nanosensors. The results show that cyanogen is weakly adsorbed on the pristine B<sub>12</sub>N<sub>12</sub> and consequently its electrical properties are changed insignificantly. In order to improve the properties of the nanocage sensor, Sc doping process was investigated. The obtained results show that doping process changes electrical properties of B<sub>12</sub>N<sub>12</sub> dramatically. Furthermore, adsorption of the cyanogen on the exterior surface of Sc-doped B<sub>12</sub>N<sub>12</sub> proves strong physisorption with E<sub>ads</sub> equal to -73.20 kJ mol<sup>-1</sup>. UV-Vis spectra display new absorption peaks confirming sensing ability of Sc-doped B<sub>12</sub>N<sub>12</sub> for detection of the cyanogen molecule. Desired nanosensor has short recovery time because adsorption energy of NCCNmolecule is not too large. It is expected that Sc-doped B<sub>12</sub>N<sub>12</sub> acts as new potential nanosensor to detect toxic cyanogenmolecule.https://www.physchemres.org/article_14142_f47a83ce84ca32b2c73caa0d71d1e8dc.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Prediction and Optimization of the Effects of Combining Ultrasonic Waves and Solvent on the Viscosity of Residue Fuel Oil by ANN and ANFIS3333531457810.22036/pcr.2016.14578ENAkbar Mohammadi DoustDepartment of Chemical Engineering, Faculty of Engineering, Razi University, Kermanshah, IranMasoud RahimiDepartment of Chemical Engineering, Faculty of Engineering, Razi University, Kermanshah, IranMostafa FeyziFaculty of Chemistry, Razi University, P. O. Box: +98-67149, Kermanshah, IranJournal Article20160108In the present work, the influences of temperature, solvent concentration and ultrasonic irradiation time were numerically analyzed on viscosity reduction of residue fuel oil (RFO). Ultrasonic irradiation was applied at power of 280 W and low frequency of 24 kHz. The main feature of this research is prediction and optimization of the kinematic viscosity data. The measured results of eighty-four samples, including 336 data points, were developed by artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). The ANN predictions were also compared with the ANFIS approach by means of various descriptive statistical indicators, including absolute average deviation (AAD), average relative deviation (ARD) and coefficient of correlation (R<sup>2</sup>). The AAD and R<sup>2</sup> of the developed ANN model for kinematic viscosity prediction of overall set were 0.0107 and 0.99384, respectively. On the other hand, for ANFIS approach, the AAD of 0.02112 and R<sup>2 </sup>of 0.99279 were attained. Although accuracy and precision of the ANN model were more than the ANFIS approach, it has been illustrated that the proposed ANN and ANFIS models have a superior performance with acceptable errors on the RFO kinematic viscosity estimation. Findings of this research clearly revealed that the neural network and neuro-fuzzy approaches could be successfully employed for prediction and optimization of kinematic viscosity of RFO and high viscosity materials in oil processes.https://www.physchemres.org/article_14578_f09955b146252e4ef20285867fde8370.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Conductometric Analysis of some Ionic Liquids, 1-Alkyl-3-methylimidazolium Bromide with Aspirin in Acetonitrile Solutions3553681465810.22036/pcr.2016.14658ENHemayat ShekaariPhysical Chemistry Department, University of Tabriz, Tabriz, IranMohammed Taghi Zafarani-MoattarUniversity of TabrizSeyyedeh Narjes MirheydariUniversity of TabrizJournal Article20160223In recent years, ionic liquids have been used in pharmaceutical processes. Therefore, having a deep insight into the ion association behavior of ionic liquids in the presence of a drug is of particular importance. So, in this work, the molar conductivities of the ionic liquids, 1-alkyl-3-methylimidazolium bromide, [C<sub>n</sub>MIm]Br (n = 4, 6 and 8) in various concentrations of aspirin (ASA) in acetonitrile (MeCN) solutions are determined in very diluted region of ILs, (molality less than 0.01 mol kg<sup>-1</sup>) and at 298.15 K. The obtained conductivity data were analyzed by low concentration Chemical Model (lcCM) of conductance equation. Using this model the limiting molar conductivities (L<sub>0</sub>) and ion association constants (<em>K<sub>A</sub></em>) were calculated. The results show that the L<sub>0</sub> and <em>K<sub>A</sub></em> values of ionic liquid are affected by the alkyl chain length of cation and the concentration of ASA. The values of L<sub>0</sub> and <em>K<sub>A</sub></em> decrease as the alkyl chain length of cation and ASA concentration increase. The <em>K<sub>A</sub></em> was also used to calculate the standard Gibbs energy ( ) of ion-pairing association. In general, 1-butyl-3-methylimidazolium bromide, [BMIM]Br, has the low values of ion-pair formation and the high negative values of and stronger interaction between [BMIM]Br and ASA.https://www.physchemres.org/article_14658_425d3e6789e7ba80a486bbb020cad4a7.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Thermal Degradation Kinetic Study of a Fuel-rich Energetic Mixture Containing Epoxy Binder3693781468610.22036/pcr.2016.14686ENMohammad Reza SoviziMalek Ashtar University of TechnologyGhasem FakhrpourDepartment of Chemistry, Malek Ashtar University of TechnologyAli Reza MadramDepartment of Chemistry, Malek Ashtar University of TechnologyJournal Article20160228 In this work, thermal degradation behavior of a fuel-rich energetic mixture containing epoxy binder was studied by thrmogravimetric analysis and differential scanning calorimetry under dynamic nitrogen atmosphere at different heating rates. Variation of the thermal degradation activation energy of the mixture was evaluated by differential and integral isoconversional methods <em>via</em> AKTS software package. Model fitting methods were used to determine the reaction model and pre-exponential factor of thermal degradation of the energetic mixture. Verification of the thermal degradation reaction model was done by differential master-plot method. The calculated values of ln<em>A</em> and <em>E<sub>a</sub></em> of the energetic mixture, according to Kissinger method, were 23.9 1 s<sup>-1</sup> and 155 kJ mol<sup>-1</sup>, respectively. Self-accelerating decomposition temperature and explosion critical temperature of the energetic mixture were determined to evaluate the thermal stability.https://www.physchemres.org/article_14686_3f568ffc806a9e915d85bd25085b2640.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Kinetic Aspects of Tetrahydrobenzo[b]pyran Formation in the Presence of Fructose as a Green Catalyst: a Mechanistic Investigation3793901473310.22036/pcr.2016.14733ENSayeydmosatfa Habibi-khorassaniDepartment of Chemistry, University of Sistan and Baluchestan, P.O.Box 98135-674, Zahedan, Iran0000-0003-4270-1895Mehdi ShahrakiDepartment of Chemistry
Faculty of Science
University of Sistan and Baluchestan
Zahedan, IranAli EbraiimiDepartment of Chemistry
Faculty of Science
University of Sistan and Baluchestan
Zahedan, IranSayyede Shadfar PourpanahDepartment of Chemistry
Faculty of Science
University of Sistan and Baluchestan
Zahedan, IranJournal Article20160113The kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (UV-Vis spectrophotometry method). The influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of the pseudo-first order kinetic model. Based on the experimental data, the overall order of the formation reaction of tetrahydrobenzo[b]pyran followed the second-order kinetics and under pseudo-order conditions the partial orders with respect to 1, 2 and 3 were one, one and zero, respectively. Kinetic values (k and E<sub>a</sub>), associated with the activation parameters (Δ<em>H</em><sup>‡</sup>, Δ<em>S</em><sup>‡</sup> and Δ<em>G</em><sup>‡</sup>) of the reaction were calculated using the Eyring equation from variable temperature in kinetic studies. The initial step of the presented mechanism was determined as a rate-determining step (<em>k</em><sub>1</sub>) and t was confirmed using the steady state approximation.https://www.physchemres.org/article_14733_f2b2866de69c409edbc470614b6bf9c2.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Prediction of Fe-Co-Mn/MgO Catalytic Activity in Fischer-Tropsch Synthesis Using Nu-support Vector Regression3914051477610.22036/pcr.2016.14776ENAli AkbarMirzaeiUniversity of
Sistan and BaluchestanSomayeh GolestanUniversity of Sistan and BaluchestanSeyed-Masoud BarakatiUniversity of Sistan and BaluchestanJournal Article20160215Support vector regression (SVR) is a learning method based on the support vector machine (SVM) that can be used for curve fitting and function estimation. In this paper, the ability of the nu-SVR to predict the catalytic activity of the Fischer-Tropsch (FT) reaction is evaluated and the result is compared with two other prediction techniques including: multilayer perceptron (MLP) and subtractive clustering-adaptive neuro-fuzzy inference system (SUB-ANFIS). The Fischer-Tropsch synthesis (FTS) was studied in a fixed bed micro-reactor under different operating conditions. An extensive experimental data set of MgO supported Fe-Co-Mn catalyst was used to predict the FTS. The input variables of three aforesaid models were: reactor temperature, H<sub>2</sub>/CO ratio and total pressure, while the CO conversion (catalytic activity) was used as an output variable. Finally, the achieved results from these approaches were compared. The results reveal that thenu-SVR model has more accurate (MSE = 0.0014) than the MLP (MSE = 0.0097) and ANFIS (MSE = 0.0043) approaches.https://www.physchemres.org/article_14776_110aeb6e3df2617fec0346a603a90bb4.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Thermal Conductivity of Reduced Graphene Oxide by Pulse Laser in Ethylene Glycol4074151477710.22036/pcr.2016.14777ENMohhamad Mahdi HeyhatAssistance professorSalimeh KimiagarIslamic Azad University- central Tehran Branch - Tehran - IranNarjes Ghanbaryan Sani Gasem Abadmaster studentElnaz Feyzimaster studentJournal Article20160226Graphene oxide was prepared using modified Hummers method. Stable ethylene-glycol nanofluids containing graphene oxide nanosheets were provided. Nd: YAG pulsed laser was applied to prepare reduced nanofluids. Experimental results revealed that thermal conductivity of the nanofluids is increased with increasing the concentration of graphene oxide (GO) in ethylene glycol. The enhancement ratio of 0.05% mass fraction of GO was 16.32%. Thermal conductivity improved with increasing the temperature about 14.28%. The dynamic light scattering and results of zeta potential analyses, after one week and eight months, showed the same results which demonstrated the stability of nanofluids.https://www.physchemres.org/article_14777_becb56bea96f71353f7af494d696ccc1.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Ab Initio Theoretical Studies on the Kinetics of the Hydrogen Abstraction Reaction of Hydroxyl Radical with CH3CH2OCF2CHF2 (HFE-374pc2)4174251482310.22036/pcr.2016.14823ENVahid SahebKerman UniversityJournal Article20160229The hydrogen abstraction reaction of OH radical with CH<sub>3</sub>CH<sub>2</sub>OCF<sub>2</sub>CHF<sub>2</sub> (HFE-374pc2) is investigated theoretically by semi-classical transition state theory. The stationary points on the potential energy surface of the reaction are located by using KMLYP density functional method along with 6-311++G(d,p) basis set. Vibrational anharmonicity coefficients, x<sub>ij</sub>, required for semi-classical transition state theory calculations, are computed at the same level of theory. The geometries are re-optimized by M06-2X/6-31+G(d,p) level. Single-point energy calculations are carried out by the CBS-Q combination method. Thermal rate coefficients are computed over the temperature range 200-2000 K and they are shown to be in accordance with the available experimental data. On the basis of the computed rate coefficients, the atmospheric lifetime of HFE-374pc2 is estimated to be about 2 months.https://www.physchemres.org/article_14823_a02796817fe0973898217a3fa8f8765f.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Sensing Activity of a New Generation of Thiourea-based Receptors; A Theoretical Study on the Anion Sensing4274401482510.22036/pcr.2016.14825ENNazanin Noroozi-ShadFerdowsi University of MashhadMostafa GholizadehFerdowsi University of MashhadMohammad IzadyarFerdowsi University of Mashhad0000-0002-3795-9982Journal Article20160128 A theoretical density functional theory (DFT) study was performed on a series of the neutral N-phenylthiourea substituents (<em>p</em>-OC<sub>2</sub>H<sub>5</sub>, <em>p</em>-CH<sub>3</sub>, <em>m</em>-CH<sub>3</sub>, H, <em>p</em>-Cl, <em>p</em>-Br, <em>m</em>-Cl, and <em>p</em>-NO<sub>2</sub>) as the sensor of acetate and fluoride anions. The hydrogen bond character was analyzed as a scale of the sensing activity. It was confirmed that hydrogen bond between the <em>p</em>-NO<sub>2</sub> derivatives of N-phenylthiourea and fluoride anion is stronger than acetate in CH<sub>3</sub>CN as a solvent. Therefore, N-(<em>p</em>-nitrophenyl) thiourea acts as a better chemical sensor in fluoride detection. For the investigation of the N-H bond properties, donor-acceptor interaction energy through the natural bond orbital analysis was obtained. Topology analysis by estimation of the kinetic and potential energy densities of the hydrogen bonds was done. Finally, some correlations between the quantum chemistry descriptors and sensing characters of the studied compounds were obtained and analyzed.https://www.physchemres.org/article_14825_8311ade4dbd38bc7f79633573a88de6a.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Calculation of Quasi-one-dimensional Interacting Electron Gas Using the Hartree-Fock Method4414491487510.22036/pcr.2016.14875ENGholam HosseinBordbarShiraz UniversityN. TaheriShiraz UniversityJournal Article20151127In this paper, the Hartree-Fock method has been formulated to investigate some of the ground state properties of quasi-one-dimensional interacting electron gas in the presence of the magnetic field. The bare coulomb interaction between electrons has been assumed. For this system, we have also computed some of its thermodynamic and magnetic properties such as the energy, pressure, incompressibility, spin-polarization and magnetic susceptibility for different values of the magnetic field. Based on the results, the total energy increases by increasing the density for all relevant magnetic fields. The system becomes more stable by increasing the magnetic field. The system also shows a phase transition at high magnetic fields. https://www.physchemres.org/article_14875_c8df3f3ced109c98ad13e36eb9c40b2f.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Theoretical Calculations of the Effect of Finite Length on the Structural Properties of Pristine and Nitrogen-doped Carbon Nanotubes4514671490010.22036/pcr.2016.14900ENFahimeh ShojaieDepartment of Photonic, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman,Iran.Journal Article20160223The effect of impurities on quantum chemical parameters of single-walled nanotubes (SWNTs) was studied using density functional theory (DFT). The density of states (DOS), Fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. It was found that this nanotube remains metallic after being doped with one nitrogen atom. The partial density of states (PDOS) of spin up and spin down electrons shows that the SWNTs and nitrogen doped single-walled nanotubes (N-SWNTs) are anti-ferromagnetic. Comparing the results of SWNTs with N-SWNTs, it can be shown that there is a relationship between the energy gap and the DOS. The relationship between the thermodynamic properties and the binding energies of nanotubes is similar to the energy gap and the DOS relation.https://www.physchemres.org/article_14900_53024b84e4ff863f5431ccd8d85aafef.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Accountability of Modern Adiabatic Connection-Based Double-Hybrids Constructed from Cubic and Quadratic Integrand Functions for Dipole Polarizabilities of Water Nanoclusters4694771494310.22036/pcr.2016.14943ENMojtaba AlipourDepartment of Chemistry, College of Sciences, Shiraz University, Shiraz, IranJournal Article20160205In this work, we dissect the performance of two modern Perdew-Burke-Ernzerhof (PBE)-based double-hybrid (DH) density functionals to predict the isotropic and anisotropic polarizabilities of water nanoclusters (H<sub>2</sub>O)<em><sub>n</sub></em> [<em>n </em>= 2-6]. The considered models include the cubic integrand (CI) and quadratic integrand (QI) functions as well as the spin-opposite-scaled (SOS) scheme for perturbative correlation term. It is shown that all the tested CIDHs and QIDHs underestimate the isotropic polarizabilities, while in the case of anisotropic polarizabilities there is also overestimation of data for a few of nanoclusters when employing the PBE-QIDH-OS model. Putting all the results together, the recommended DH functionals for predicting the dipole polarizabilities of water nanoclusters turned out to be PBE-CIDH, PBE-CIDH-OS, PBE-QIDH, and PBE0-DH with deviations smaller than those provided from Møller-Plesset perturbation calculations.https://www.physchemres.org/article_14943_8fd3d37f32d4083df26222604c474bbf.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901An Accurate Correlation to Estimate Saturated Molar Volume of Liquids4794881499210.22036/pcr.2016.14992ENMehrdad HonarmandDepartment of Mechanics, Tiran Branch, Islamic Azad University, Isfahan, IranMohammad Reza Haghighat NezhadChemical Engineering Department, Shahreza Branch, Islamic Azad University, Shahreza, IranVahid PourgharibDepartment of Mechanics, Tiran Branch, Islamic Azad University, Isfahan, IranMohsen BeigiDepartment of Mechanics, Tiran Branch, Islamic Azad University, Isfahan, IranJournal Article20160127There are a number of techniques available to estimate saturated-liquid molar or specific volumes or densities of liquids. In this study, a new empirical correlation is presented to calculate volume of saturated liquids as a function of critical volume, reduced temperature and acentric factor. An optimization algorithm is utilized to obtain unknown parameters of this correlation by fitting them with the data bank. The accuracy of presented correlation is evaluated <em>vs</em>. mostly used methods and the result indicates the priority of new equation than other methods used in this work with average absolute relative deviation 1.7%.https://www.physchemres.org/article_14992_630f4615d32695dd93fc7bd2c776c7fe.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Experimental and Theoretical Study of Phase Equilibria in Aqueous Mixtures of Lactic Acid with Benzyl Alcohol and p-Xylene at Various Temperatures4895051506210.22036/pcr.2016.15062ENH Ghanadzadeh GilaniAli Ghanadzadeh GilaniDepartent of chemistry, University of Guilan. Rasht, Iran0000-0002-3931-0570F Borji PeydehS.L. Seyed SaadatS AhmadifarJournal Article20160127Liquid-liquid equilibria for the (water + lactic acid + benzyl alcohol or <em>p</em>-xylene) ternary systems were investigated at atmospheric pressure and in the temperature range from 298.15-318.15 K. The studied systems exhibit two types of liquid-liquid equilibrium (LLE) behavior. The system consisting of benzyl alcohol displays type-1 LLE behavior, while a type-2 behavior is exhibited by the other system. The quality of the experimental tie line data was determined using the Othmer-Tobias and Hand equations. Distribution coefficients and separation factors were calculated over the biphasic region. The experimental tie line data were regressed using the UNIQUAC and NRTL models and the binary interaction parameters were obtained.https://www.physchemres.org/article_15062_950eee4b3f46ddc77cb078e94e2e242e.pdfIranian Chemical SocietyPhysical Chemistry Research2322-55214320160901Phase Equilibria of the Ternary System Water + Phosphoric Acid + 1-Nonanol at Different Temperatures5075181524110.22036/pcr.2016.15241ENSina ShekarsaraeeDepartment of Chemistry, Faculty of Science, Guilan University, Rasht, IranJournal Article20160201The purpose of this reaserch is to measure the phase equilibrium data of the ternary system (water + phosphoric acid + 1-nonanol) at different temperatures. Experimental solubility curves and tie-line points for the system were obtained at <em>T</em> = 298.2, 308.2 and 318.2 K and ambient pressure. The binodal curve data were detected by the cloud point method. The mass fractions of each layer were achieved by acid-base and the Karl-Fisher titration, accompanied by refractive index calibration curves. A type-1 LLE phase diagram was observed for this ternary system. The equilibrium tie-line data were correlated <em>via</em> the UNIQUAC and NRTL thermodynamic models. The experimental tie-lines of the studied system were satisfactorily regressed to the models. The reliability of the experimental end points was determined using the Othmer-Tobias and Hand plots. Distribution coefficients and separation factors were calculated over the non-miscible parts. For the separation process, separation factor should be greater than one. For the investigated system, the facor was suitable for separation treatment in all concentrations of phosphoric acid and three temperatures.https://www.physchemres.org/article_15241_f1fe748080e1edda3e94f709ee9b6871.pdf