Iranian Journal of Chemical Engineering (IJChE)

Abstract The thickening of the iron ore tailings allows process water to be partially recovered and recirculated, also it reduces the fresh water consumption, which results in lower operating costs and less environmental impacts. The settling characteristics of the mineral components of an iron ore tailing in the thickening process may be different under various pulp conditions. Hence, the study of the characteristics of the mineral components of the iron ore tailings separately can provide very useful information about the thickening of an iron ore tailing. In this research, the settling behavior of the main mineral components of iron ore tailings including quartz and magnetite have been investigated under various operational conditions. The quartz and magnetite showed different settling behaviors, so as the maximum settling rate of quartz was achieved under different pulp conditions than that of magnetite was. There was a big difference between the maximum settling rates of quartz and magnetite, as the maximum settling rates of quartz and magnetite were 197 and 873 m/h respectively. In the thickening of an iron ore tailing, the pulp conditions must be set based on the settling behavior of the mineral component with the lowest settling rate.

Abstract The removal of Acrylonitrile (AN) from waste gas streams using biological methods, due to their better performance, has recently gained more attraction. The purpose of this research is modeling the AN removal by a bio-filter. The validation of the model is done by using the experimental data of a bench-scale bio-filter bed column including yard waste compost and shredded hard plastics and thickened municipal activated sludge. In this work the kinetics of the biodegradation of Acrylonitrile is first investigated. Then equations of the biofilm and air are obtained at a steady state and constant temperature. The unknown parameters of the model are determined by the least square optimization method along with solving the model equations using MATLAB. For inlet concentrations less than 1 g/m³ the model results show reasonable similarities to the experimental data. The effect of various parameters on the bio-filter performance is evaluated. The Peclet number, biofilm thickness and biomass concentration are the most important parameters. The proposed model can be useful for design purposes.

Abstract One of the methods to reduce the particle size is the GAS method. In this method, the solute and antisolvent should be dissolved well in a solvent. But the solute is not dissolved in a solvent. The aim of studying this model is to determine the phase equilibrium and thermodynamic conditions of (CO₂, solvent, 5-Fluorouracil) in the GAS process. The solvents include methanol, ethanol, acetone, 1-propanol, and 1-butanol. The Peng-Robinson equation of state with a linear combination of Vidal and Michelsen mixing rules (PR-LCVM) was used for the thermodynamic modeling. The volume expansion of the binary system (CO₂, solvent) and ternary system (CO₂, solvent,5-Fluorouracil) at the temperature range of 313.15-319.15 K was investigated. The P_min values for the binary system were 66.7, 69.6, 60, 73.7, and 76.8 bar respectively for methanol, ethanol, acetone, 1-propanol, and 1-butanol at 313.15 K,. The P_min for the ternary system was also calculated. The comparison between the P_min values of binary and ternary systems showed that for a constant temperature and a certain solvent, the calculated minimum pressure in the ternary system was greater than the same in the binary system

Abstract The optimization of the ammonia synthesis plant to increase the production of ammonia is studied in this line of research. In this paper, the steady-state ammonia synthesis is simulated using the Aspen HysysV.11 software. By comparing the simulation results with the industrial information, a mean relative error of 7.71 % was obtained, which indicated the high accuracy of the simulation. Then, four effective variables were selected from among 11 independent variables by the Plackett-Burman method. The effects of the Hydrogen flow in the feed stream, Recycle stream pressure, Feed stream temperature, and input temperature of the third reactor were investigated, and the response surface design method of the central composite design was performed to plant optimize. It is obtained that the Hydrogen flow in the feed stream is equal to 6255 , the feed stream pressure is equal to 205 bar, the temperature of the excess stream inlet in the first reactor is equal to 663 K, and the temperature of the stream inlet of the second reactor is 677.5 K which increased the ammonia production by 7.5 %.

Abstract The design of installations in the chemical industry requires knowledge of the thermodynamic properties of liquid mixtures. In the absence of experimental data, accurate predictive methods are needed. In this work, the refractive index and the surface tension are experimentally determined at different temperatures and atmospheric pressure, for the binary and ternary systems of benzyl alcohol, n-hexanol and water, less studied in the literature. Two models were developed for the correlation of excess surface tension with composition, normalized temperature and refractive index. The statistical processing of the experimental data with the multiple linear regression method allowed the development of a model for which, in the validation stage, the correlation coefficient was 0.9086 and the standard deviation was 4.36. With the best performing neural model, a correlation coefficient of 0.9727 and a standard deviation of 2.14 were obtained in the validation stage.

Abstract The rapid growth in global demand for clean and sustainable energy has intensified the need for efficient hydrogen (H2) production technologies. Thermochemical recycling of plastic waste has emerged as a promising approach, offering both environmental benefits and the generation of high-purity, low-carbon H2. This study evaluates the technical and economic feasibility of H2 production from diverse plastic waste streams using Aspen HYSYS and the Aspen Economic Analyzer. The process integrates polymer pyrolysis, chlorine removal, and steam reforming. Feedstocks (200×10³ t/y) include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET), and mixed industrial and municipal waste from packaging (PKG), medical (MED), automotive (AUT), municipal solid waste (MSW), construction (CON), and textile (TEX) sectors. H2 production yield strongly depends on the feedstock composition, ranging from 0.14 to 0.31 t H₂/t feed. PET with the lowest H/C ratio, exhibits the lowest yield, whereas PE and PP achieve the highest yields, albeit with incomplete carbon-to-CO conversion. Oxygenated polymers, such as PET, generate the highest CO2 emissions (~1.4 t/t feed). Economic analysis indicates that PE and MED are the most cost-effective feedstocks, with gross margins of 62 and 66% and annual net profits of 232×10⁶ and 223×10⁶ USD, respectively.

Abstract A batch process was developed for the production of biodiesel from high free fatty acid feedstocks. The mixed-integer nonlinear programming (MINLP) problem, caused due to applying the hierarchical procedure together with Malone’s algorithm for the conceptual design, was solved. Meanwhile, the optimum states of major process parameters such as the utilization of the process equipment, paralleling, splitting, and the merging of unit operations, the process cycle time (CT), and the combination of batch and continuous units were determined. Based on the present optimization study, the optimum value of the process cycle time and the optimum number of the esterification reactors in series were obtained as 3.257 h/batch and 3 stages respectively. The batch process was found to be suitable for a capacity of less than 260 tons/yr, while the continuous process was suitable for a capacity of greater production rates. The results showed that the production rate had a direct effect on the economic potential of the process and that it should be set at its maximum possible practical value. Also, the break-even point for the optimum state occurred at the production rate of 130 tons/yr.

Abstract To improve quality attributes of the final dried product and execute a better management of the required energy, optimal process and technology it is essential to dry agri-food materials. This work is aimed at studying the dehydration characteristics and qualitative traits (color, shrinkage, rehydration ratio) of apple in a rotating-tray convective dryer with different operational variables. Furthermore, to model the dehydration curves, the usage of some well-known semi-theoretical models and artificial neural networks (ANNs) was evaluated. The drying experiments were conducted by applying the constant thickness of the samples (3 mm), different air temperatures (50‒85 °C) and flow rates (1 and 2 m s^-1) as well as three tray rotating speeds (0, 6 and 12 rpm). In addition to significant (P < 0.05) reduction caused by increasing the temperature and flow rate, the process duration was considerably decreased by the increment in the tray rotating speed. The moisture diffusion inside the slices (2.708 × 10^-9 ‒ 8.337 × 10^-9 m² s^-1) was facilitated by increasing the values of evaluated variables. The average values for the activation energy changed from 20.47 to 23.80 kJ mol^-1. In comparison with the thin layer models, artificial networks showed better performance in modeling the curves. Although drying parameters did not significantly affect the quality of studied properties, in general, higher drying air velocities and temperatures deteriorated the quality of the final products

Abstract Humidification-dehumidification (HD) desalination has been identified as a sustainable, reliable, and energy-efficient technology for producing freshwater on a small scale. VP-HD systems operated at one-stage, multi-stage, and multi-feeding vacuum humidification-over atmospheric pressure dehumidification arrangements can be the recent modifications of an HD system. The present study offers a theoretical investigation and experimental verification of two VP-HD systems, encompassing both sub-atmospheric pressure humidification and over-atmospheric dehumidification. Two designs are evaluated, one comprising a three-stage humidification setup and the other featuring a three-feeding one-stage humidification apparatus. The results show which design has better performance than previous conventional and variable pressure HD systems. The parametric analysis reveals that an upsurge in freshwater generation is observed with an increase in air temperature, feed salinity, and a decrease in humidifier pressure. Additionally, an optimal water-to-air ratio is identified. The study further highlights that multi-stage humidification yields better results concerning freshwater productivity and specific power consumption. Three-stage humidification is found to be the most efficient in terms of freshwater production and specific power consumption, achieving the highest values of 1.93 L h^-1 m^-2 and 0.21 kWh L^-1, respectively. The agreement between theoretical and experimental outcomes is deemed satisfactory.

Abstract The present study numerically investigates the removal of hydrogen sulfide (H₂S) from crude oil using natural gas as a stripping medium in a T-junction microchannel through three-dimensional computational fluid dynamics (CFD) simulations. The microchannel geometry was adapted from a previously reported experimental configuration and further optimized to reduce natural gas consumption and operating temperature. The Volume of Fluid (VOF) model coupled with the SIMPLE algorithm was implemented in ANSYS Fluent to simulate the gas–liquid two-phase flow and evaluate mass transfer characteristics. Simulations were conducted for gas flow rates of 200–1200 mL/min and oil temperatures in the range of 20–40 °C. The results showed that the H₂S removal efficiency increased with crude oil temperature and gas flow rate but decreased with higher oil flow rate. The predicted efficiencies ranged between 65.7% and 77.8%, in close agreement with experimental data (maximum relative error: 5.6%). The cold-stripping configuration achieved high desulfurization performance even at low gas temperatures (about 18 °C) while reducing gas consumption by nearly one-third compared with conventional units. This study proposes validated correlations and optimized operating parameters for efficient desulfurization of sour crude oil using a microchannel-based cold stripping process.

Abstract The impregnation of the alumina support with the PdCl₂ solution was investigated in batch and semi-batch operation modes using a recycle packed-bed reactor. The UV-visible analysis was used to evaluate the kinetics of the adsorption of Pd on the alumina support. The adsorption data related to transient palladium showed that the adsorption of Pd was very rapid and completed within few minutes. Bi-metallic Pd-Ag/Al₂O₃ catalysts were synthesized by the sequential impregnation method. CO-chemisorption, CO-TPD and FE-SEM tests were used to characterize the synthesized bi-metallic samples. The catalytic performance of the samples was evaluated for the tail-end acetylene selective hydrogenation process in a fixed-bed reactor. Moreover, the deactivation of the catalysts was evaluated mathematically by the integral method of analysis, considering reaction kinetics as power laws in terms of n^th orders in H₂ and C₂H₂ partial pressures. It was observed that by the batch-wise addition of the Pd precursor solution, a sample, with the lowest amount of Pd dimmers that had the highest ethylene selectivity and lowest hydrogenation reaction rate, was obtained.

Abstract The polysulfone mixed matrix membranes (MMM) with different concentrations of graphene oxide (0, 0.25, 0.5 wt % of the polymer) are fabricated by a phase separation method. The cross-sectional structures and their upper surface were assessed by the (SEM) surface roughness of the membranes assessed by (AFM). The mechanical and thermal stability of the fabricated membranes were evaluated as well. The separation of Carbon dioxide, nitrogen and methane from natural gas was considered. Also, by increasing the concentration of graphene oxide in the polymer matrix, the thickness of the spongy structure increases and the holes of the finger-like membranes are also destroyed. From the cross-sectional images of the outer surface of the MMM, it was concluded that an active selector layer was created on the lower surface of the membrane. The membrane tensile strength and the length of the membrane at fracture point increased slightly with an increase in the concentration of graphene oxide. Transition Glass temperature of the membrane increased by the addition of graphene oxide to the structure. From TGA analysis, in the presence of graphene oxide, the thermal stability improved. From the gas permeation test, by the addition of 0.25 % of graphene oxide to the polymer, CO₂ permeability was increased from 61.22 GPU to 76.04 GPU, while the addition of 0.5 wt % resulted in a lower permeability (69.55 GPU). The Nitrogen gas permeation flux of membranes decreased from 10.93 GPU to 3.91 GPU by the addition of 0.50 wt % of graphene oxide. The Methane gas permeation flux is reduced from 11.31 GPU to 6.95 GPU and 4.92 GPU by the addition of 0.25 % and 0.50 % of graphene oxide respectively. In conclusion, an increase in the concentration of graphene oxide increased the carbon dioxide selectivity.

Abstract This study presents a numerical investigation into the influence of the magnet position and its distance from the channel inlet on heat transfer and flow behavior of ferrofluid (FF), including Fe₃O₄/water flowing through a horizontal channel under a constant wall heat flux. Three magnet positions were considered—at the inlet, middle, and outlet of the channel—to identify the best configuration for heat transfer enhancement. Permanent magnets with a remanent magnetic flux density of 0.4 T were modeled. The nanoparticle concentration was 5 Vol.%, and the Reynolds number was 100. The effects of magnet positions on the local magnetic flux density, Kelvin force, streamlines, velocity and temperature distributions, and Nusselt number (Nu) were investigated. The problem was solved by assuming incompressible, laminar, and steady-state flow. The Galerkin weighted residual finite element method was used to solve the governing equations simultaneously. Results revealed that when magnets were positioned at the inlet or outlet, the magnetic field effects were localized and produced minimal impact on the flow and temperature fields. Conversely, when the magnets were located in the middle of the channel, the most substantial magnetic field gradients and Kelvin forces were generated, which created recirculation zones and increased fluid mixing, resulting in a more uniform temperature distribution and a significant enhancement in the local Nu and an average Nu of 5.31. Finally, this study proposes placing the magnet in the middle of the channel as the most effective configuration for enhancing convection heat transfer.

Abstract Metal-organic frameworks (MOFs) have emerged as extended-network, highly tunable, crystalline hydrogen storage adsorbents. The uptake of H₂ on Zn₄O-based MOFs with different linkers was studied in the current work. The binding energies, consecutive binding energy and step energy of H₂ adsorption on MOF-177, MOF-200 and a newly defined MOF (named NEW-MOF) have been calculated on different possible sorption sites, using DFT/Dmol³/PBE. The linkers have the same benzene ring in center, but different numbers of phenyl rings, including 3, 6 and 9 phenyl rings in MOF-177, MOF-200 and NEW-MOF around the center ring, respectively. Our study results showed that the binding energy of the H₂ molecules with the linker NEW-MOF was -4.165 kcal/mol, more negative than those obtained for MOF-177 (-3.276 kcal/mol) and MOF-200 (-3.438 kcal/mol). The obtained thermo-favorability may be attributed to the less steric hindrance for adsorption of H₂ on the MOF with the larger linker. Step energy results showed that the linkers of MOF-177, MOF-200 and NEW-MOF could adsorb 7, 9 and 12 number of H₂ molecules, respectively. Results also disclosed adsorbed moles of H₂ per 1×1×1 unit cell of the MOFs decreases with increasing the linker length according to the order of 0.263 (for MOF-177), 0.16 (for MOF-200) and 0.137 (for NEW-MOF), mainly due to reduced packing density of the active sites in the MOFs with larger linkers. The most negative binding energy was also tabulated for the perpendicular approaching of H₂ molecules to the node of the central phenyl ring with the bonding distance of 3.19 Å from the linker.

Abstract The Dry Reforming of Methane, which uses methane and carbon dioxide, the two greenhouse gasses, to produce synthesis gas, has received considerable attention recently. In this work, the equilibrium conversion that is the maximum possible conversion has been obtained experimentally and theoretically. The equilibrium concentration for the Dry Reforming of Methane (DRM) has been calculated using Thermodynamic equilibrium and compared with the experimental equilibrium concentration. The reaction coordinate (ε), Gibbs free energy (G), reaction equilibrium constant (K), and reaction stoichiometric coefficients are used for the calculation of the reaction progress and the equilibrium composition in DRM at different temperatures. These parameters have been calculated by two primary methods, direct and Lagrange, and compared with an empirical equilibrium that has been revealed by the activity test on Ni/Al₂O₃ catalyst. The result shows that none of those can’t make an exact determination of empirical equilibrium compositions, but there was a relatively good agreement between the Lagrange method and the empirical equilibrium. No significant difference has been observed between these methods and empirical conditions at high temperature.

Abstract The central composite design (CCD) was employed to investigate the adsorption of Pb(II) and Zn(II) metal ions as well as methylene blue (MB) as an aromatic anion by a new EDTA/MnO₂/CS/Fe₃O₄ synthesized nanocomposite. The effect of possible affective factors including the contaminant concentration (20-200 mg/L), pH (2-8), adsorbent content (0.1-0.9 g/L), and contact time (10-110 min) on the adsorption of the metal ions using response surface methodology (RSM) were studied. The highest removal percentages predicted by the model were 100.776 % and 87.069 %, respectively, for the removal of Pb(II) and Zn(II), that the value of more than 100 % in the case of Pb(II) was due to the model’s error. The effect of the simultaneous presence of methyl blue (MB) and the metal ions in the aqueous solution on the adsorption rate of each metal ion was investigated. The study of the adsorption isotherms in the single-component adsorption showed the dominance of Langmuir isotherm over the adsorption process of each pollutant (R² > 0.99). The maximum adsorption capacities according to the Langmuir model were 310.4 and 136 mg/g for lead and zinc ions, respectively, and 421.1 mg/g for methyl blue. The results showed that the studied nanocomposite still had high efficiency after five consecutive adsorption-desorption cycles

Abstract In the present investigation, the physicochemical parameters of dyeing woolen yarn with the CI Acid Red 1 dye in terms of the kinetics and thermodynamic of adsorption were studied. Different models (Zero order, First order, Second order, Parabolic, Cegarra–Puente and modified Cegarra–Puente models) were employed to discover a suitable dyeing apparatus. It was found that the modified Cegarra-Puente model best fitted to the investigational data with the maximum correlation (R² ≥ 0.99). The dyeing-rate constant, half dyeing times, rise time and fixation time were then calculated. Thermodynamic parameters, for instance the Gibbs free energy (∆G^#), enthalpy (∆H^#), entropy (∆S^#), and the activation energy (E_a), were considered. The thermodynamic parameters imply that the dying procedure could be improved by increasing the system temperature. Also, dyeing woolen yarns with CI Acid Red 1 decreases randomness and enhances the order of reaction systems by immobilizing dye molecules onto the solid fiber surface

Abstract The fully mixed continuous stirred tank reactor is an important type of industrial reactors mainly used to produce high volume products such as petrochemicals, detergents, sanitary products and products that are in demand in the market. Knowing the dynamic behavior of chemical reactors is of great importance in setting up, designing, controlling and stopping reactors. In this paper, the effect of non-dimensional numbers Damkohler and Stanton on the stability of a continuous stirred tank reactor in which a first-order exothermic reaction takes place is investigated. First, a mathematical model of the system's dynamic behavior was presented. Then, by simultaneous solving of the equations of mass and energy around the fixed point in MATLAB software, the effect of the mentioned numbers was investigated. The results show that the continuous stirred tank reactor shows different behaviors in different ranges of Damkohler and Stanton numbers. This reactor behaves unstable in small and large ranges of Damkohler and Stanton numbers due to the presence of mixed or positive and negative eigenvalues. The best range for Damkohler and Stanton numbers is close to 1, because in this range the reactor shows stable behavior due to having two negative eigenvalues. In this range, in addition to the stability, the conversion is also 100%. Finaly the ratio of Stanton to DamKohler was investigated as St / Da˃1 and St / Da = 1. If St / Da = 1, the system is in steady state, but in St / Da˃1, the system moves away from steady state.

Abstract An adaptive neuro-fuzzy inference system (ANFIS) was applied to simulate the batch adsorption of triglyceride (TG) from the human blood serum using the cinnamon powder, which has appeared as a potential biosorbent for serum purification, in our previous work. The obtained experimental results were used to train and evaluate the ANFIS model. Temperature (°C), the adsorption time (h), the stirring rate (rpm), the dose of adsorbent (g) and the adsorbent milling time (min) (or the particle sizes of the powder) were considered as the model inputs and TG removal (%) was chosen as the model response. The ANFIS model was trained with 75 % of the available data while 25 % of the remaining data was used to verify the validity of the obtained model. Sobol sensitivity analysis results indicated that the cinnamon dose with 71 % and the adsorbent milling time (or the particle size of the powder) with 15 % impact share were the most influential variables on the TG removal. Furthermore, the specific surface area and the number of reactive adsorption sites were found to be the most important characteristics of the adsorbent. Generally, the results of this study confirmed the advantages of applying the ANFIS and Sobol approaches for the data-based modeling of the bioprocesses.

Abstract The effect of adding isopropanol (ISP) to nitrogen as the fluidizing gas on the hydrodynamics of the fluidization of hydrophilic titanium nanoparticles was studied. It was shown by the pressure drop method that adding ISP reduces the minimum fluidization velocity. Wavelet transform of the pressure fluctuations of the bed was employed to identify the hydrodynamic structures. The energy of hydrodynamic structures was evaluated in each fluidization mode. It was shown that ISP reduces the inter-particle attractive forces by replacing the hydroxyl group of the hydrophilic nanoparticles with an alkyl group. Energy and recurrence analyses were used to define the characteristics of fluidization when adding ISP to nitrogen gas. The energy of macro structures increased when using ISP, having indicated a decrease in the number of bubbles and an increase in the bubble size due to the reduction of inter-particle attractive forces. The increase of the white local areas in the recurrence plots also showed the increase of the bubble size. The recurrence quantification analysis showed the increase of the larger-scale phenomena (i.e. bubbles) in the bed.

Abstract In the present work, the effect of synthesis method (simultaneous impregnation and coprecipitation) and copper to nickel active phases loading were investigated in Ni-Cu-Al catalysts. The water/ethanol molar ratio of 6 and gas hourly space velocity (GHSV) of 20000 hr^-1 were used in all the experiments. The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques. The catalytic activity results revealed that 13Ni-6Cu/γ-Al₂O₃ impregnated catalyst was more active than co-precipitated one (13NiO-6CuO-81Al₂O₃) in the same amount of compositions of active metals and Al₂O₃, but by increasing the active phases (Cu and Ni) loading in co-precipitated catalysts (24NiO-31CuO-45Al₂O₃, 31NiO-24CuO-45Al₂O₃, 40NiO-15CuO-45 Al₂O₃ and 47NiO-8CuO-45Al₂O₃), they achieved a better performance than 13NiO-6CuO-81Al₂O₃ catalyst. The 40NiO-15CuO-45Al₂O₃ catalyst showed 99% ethanol conversion, as well as 303 hydrogen yield and 4% CO selectivity at 470^oC. SEM images revealed agglomerated particles for the samples with high Al₂O₃ content and with increasing the active phase content in the catalyst the particle sizes decreased. The 40NiO-15CuO-45Al₂O₃ showed smallest particle size among the catalysts.

Abstract Ziziphus nuts are abundant in Khuzestan province, Iran, and are considered as an unwanted natural biomass waste. The present study is aimed to develop low-cost activated carbon from Ziziphus nuts as a new precursor for the removal of phosphate from the water environment.the iron oxide modification was performed to simultaneously facilitate the adsorbent separation via a simple magnetic process and increase the phosphate removal capacity. The iron oxide/activated carbon composite (IOAC) was characterized using XRD, EDX, SEM, and BET methods. The specific surface area for IOAC reached 569.41 m²/g, comparable to that of the commercial activated carbon. While other similar derived-from-biomasses activated carbon reached the phosphate removal capacity of around 15 mg/g, IOAC demonstrated the excellent phosphate removal performance of as high as 27 mg/g. Also, IOAC showed fast adsorption kinetics, achieving equilibrium in only 60 minutes. According to the results, the pseudo-second-order kinetic model was more consistent with the data related to the phosphate adsorption onto the adsorbent than the pseudo-first-order model. The adsorption results using Langmuir, Freundlich, and Webber-Morris diffusion models were interpreting. The maximum Langmuir adsorption capacity was calculated to be 27 mg/L. The adsorbent was removed from the aqueous solution via a simple magnetic process.

Abstract The synthesized polystyrene has weaknesses in terms of mechanical, physical and thermal properties which limit the use of this polymer. Therefore, the use of the mixtures of polymers can improve these properties. Different parameters like the mixing speed can affect the quality of the properties of the polymer being prepared from the mixture of several polymers. In this study, different percentages of nanocomposites in different stirring speeds have been added to polystyrene. Different tests have been performed on the prepared polymer and investigating the tests shows that in different stirring speeds the values of the tensile strength and impact resistance of the prepared polymer can be increased while the values of the Vicat Softening Temperature (vicat) and Melt Flow Index (MFI) test numbers remain constant. The obtained results from the laboratory data have been simulated by Artificial Neural Networks (ANNs) in order to predict the results for the points which have not been tested and the simulated results show that the laboratory data covered the simulated data perfectly. The results of tests show that by increasing nanoparticles, the resistance of the polymer against impacts will be increased and in addition, increasing the rate of the stirrer causes all other values of tests to increase.

Abstract In this work, the effect of the Si/Al ratio on the activity of zeolite supported bimetallic (Ni-Co) catalysts for Dry Reforming of Methane (DRM) has been studied. Samples are prepared with impregnation and sol-gel methods and then calcined at 550 °C for 2 h. The catalysts were characterized by XRD, XRF, FESEM, BET and TGA. All samples were tested in a micro reactor at three different temperatures (i.e. 700, 750, and 800 °C). Micro reactor test results showed that 800 °C was the proper temperature for DRM. The catalyst with 5 wt % of Ni and 2.5 wt % of Co supported on γ-Alumina have shown a higher H₂/CO ratio than other samples. For the zeolite supported catalysts when Ni/Co=2/1, the surface area and pore volume decreased but the H₂/CO ratio increased by increasing the Si/Al ratio. Reverse the Water Gas Shift (WGS) reaction was not very active when the catalyst and support showed a basic property. Also, the stability of the catalysts has been tested for 30h on stream.

Abstract Bone tissue engineering requires approaches to provide a suppression/promotion environment for the bone growth. Scaffold biomaterials have profound regulatory effects on the functionality of mesenchymal stem cells (MSCs). In the present study, the three-component bioceramic of selenium/reduced graphene oxide/hydroxyapatite (Se/RGO/HA) was developed and its performance to repair bone defects was compared to that of HA. The Se/RGO/HA nanocomposite scaffold was synthesized using the chemical bath technique, characterized by the X-ray diffraction spectra, field emission scanning electron microscopy, energy dispersion X-ray spectrometery, and Fourier transform infrared spectroscopy analyses. Human adipose-derived MSCs (hAD-MSCs) were used to investigate the in-vitro osteogenic properties of the Se/RGO/HA scaffold. The effect of the combined scaffold on the cell proliferation was analyzed by the MTT assay. Cell adhesion behaviors were evaluated using the optical microscopy and SEM. The osteogenic properties of the Se/RGO/HA scaffold were examined by the measurement of the alkaline phosphatase (ALP) activity and western blotting technique. The hAD-MSCs proliferation for HA and the Se/RGO/HA nanocomposite were 2 ± 0.1 and 1.1 ± 0.05 respectively. The Se/RGO/HA nanocomposite had cytotoxic effects on the KHOS-240S cancer cells. Additionally, good cell attachment and osteoblast-like morphology were characterized on the designed scaffold. The ALP activity and mineralization potential of cells seeded on Se/RGO/HA were higher than those seeded on HA. The Osteocalsin protein for Se/RGO/HA and HA were 64 ± 1 and 12 ± 0.1 respectively. Furthermore, the expression of Osteocalcin, a bone-specific protein, was synergistically increased by the incorporation of Se and RGO into HA. In conclusion, the presence of RGO inside Se could significantly increase the positive effects of HA on the osteogenic potential of hAD-MSCs.