Nashrieh Shimi va Mohandesi Shimi Iran
Year:2019 | Volume:38 | Issue:3 (93)|Papers Count:27

In the present study, catalase nanoparticles were prepared by desolvation method using ethanol and glutaraldehyde as desolvating and crosslinking agents respectively. The factors such as the amount of ethanol and glutaraldehyde, stirring rate, and synthesis time were optimized. Properties of the nanoparticles including particle size, morphology, and structural changes were characterized using spectroscopic techniques such as UV-Visible, FT-IR, DLS, and SEM. Also, their kinetic parameters were determined on based the Michaelis-Menten equation. The results of the optimization studies revealed for a phosphate buffer solution (50 mM, pH 7. 0) contain catalase (1 mg/ mL), 4-mL absolute ethanol, and glutaraldehyde (12 mg/mL), up to 70% of the enzyme activity remained. In these conditions, the average of the particles was 53. 8 nm. Investigation of the UV-Visible and FT-IR spectra showed that the formation of the nanoparticles caused the structural changes at the tertiary and secondary levels. Comparing the kinetic parameters of the native enzyme and catalase nanoparticles showed that the Vmax is the same and that the Km is increased. The physical stability of catalase nanoparticles was also investigated. Results showed that the catalase nanoparticles lost only 20% of the activity when stored in phosphate buffer solution for 72 h at 4◦ C, whereas native catalase lost 55% under the same condition, implying that the catalase nanoparticles were more stable than native catalase molecules. Therefore, catalase nanoparticles offered a great potential to stabilize enzyme molecules for various applications.

In this work, cobalt acetate/polyvinyl alcohol (Co (OAc)2/PVA) nanofibers were prepared by the electrospinning method. In the following, cobalt oxide nanofibers (CoxOy NFs) were obtained by appropriate thermal treatment. The surface morphology and diameter of the synthesized nanofibers were investigated by Scanning Electron Microscopy (SEM). The results showed that long fibers with an average diameter of around 50 nm were obtained for CoxOy NFs. By ThermoGravimetric Analysis (TGA), the appropriate temperature for calcination was obtained at about 600 ° C. The Fourier Transform-InfraRed (FT-IR) spectroscopy showed that all the organic constituents of the electrospun nanofibers were removed after calcination. For the investigation of the crystallinity of the metal oxide nanofibers, X-Ray Diffraction (XRD) was used. The crystalline phase of CoxOy nanofibers was determined as cubic. By using adsorption-desorption isotherms, the surface area of the nanofibers was obtained at about 4. 4 m2/g The electrochemical behavior of CoxOy NFs modified carbon paste electrode (CoxOy/CPE) was studied by cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry methods. The electrocatalytic activity of the modified electrode was studied towards oxidation of ethylene glycol (EG) in an alkaline medium. The obtained results showed that the CoxOy NFs/CPE has electrocatalytic ability towards the EG oxidation.

In this study, the composites of Single Wall Carbon NanoTubes (SWCNTs) functionalized with zinc oxide nanoparticles based on poly (methyl methacrylate) (PMMA) as an optical sensor were prepared by the co-precipitation method as a part of the optical sensor. Nanoparticles synthesized were identified and characterized by analysis FESEM, EDX, XRD, and FT-IR. The average size of ZnO nanoparticles doped in carbon nanotubes was estimated at about 22nm using XRD techniques. To characterize the optical properties of carbon nanotubes as a base and a basic element with high detection capability in sensors was used UV-vis spectrophotometric and the results showed, the use of carbon nanotubes functionalized with ZnO in the PMMA matrix makes improved coverage properties of nano-composite against the UV radiation by reducing the gloss and surface clarity and the transmittance of UV radiation was zero. Also, the spectral reflectance values of the prepared samples are measured by a reflectance spectrophotometer in the visible region from 400-700 nm. The color parametric values and the blackness index are calculated at about 3. 65. It was observed that in the samples containing functional carbon nanotubes the reflectivity was reduced 50% and had a better blackness.

In this study, the nanocomposite films composed of starch/gelatin/nano clay were fabricated and their physiomechanical properties were investigated. The experimental design was done via the RSM method with Design Expert 7. 0 software. The gelatin/starch weight ratio and the nanoclay weight percent were selected as independent variables and the tensile strength, Young modulus, elongation at break, and contact angles as dependent ones. The mathematical equations that identify the relationship between the dependent and independent variables were obtained. The results demonstrated that the tensile strength and modulus and the hydrophobicity of the surfacewere increased as nanoclay increased and the portion of gelatin decreased while the elongation at break showed reverse behavior. In the following, the optimization was done and the optimized values for gelatin/starch and nanoclay weight, percent were introduced to have the maximum tensile strength and minimum hydrophilicity. The optimum nanocomposites were fabricated and analyzed via FT-IR, SEM, XRD, and biodegradability tests. The obtained results showed that the nanoclay sheets were intercalated and proper dispersion of nanosheets in the polymeric matrix achieved. The nanocomposite films showed proper degradability and their weight was decreased by 40% after 6 weeks. Overall, this research work confirmed the proper potential of starch/gelatin/nanoclay nanocomposites as biodegradable food packaging films.

Environmental pollution is the result of the rapid development of industry, which is a serious problem. In this research, first ZnO nanoparticles were synthesized by hydrothermal method and then added to the preparation solution of MnO2 nanoparticles by precipitation during reduction reaction. The particle size was studied by Scanning electron microscopy (SEM). The prepared ZnO/MnO2 nanocomposite was used as a solid phase adsorbent to separate and determine the heavy metal ions of lead and cadmium in water samples. The removal efficiency of heavy metal ions and desorption conditions were determined by atomic absorption spectrometry. The effect of various parameters such as pH, amount of adsorbent, initial concentration of ions, shaking time, sample volume, and eluent type and concentration for elution of the retained heavy metal ions were evaluated and the optimum conditions were determined. The relative standard deviations for the determination of lead and cadmium ions were 4. 6-5. 2% and 1. 7-3. 4%, respectively.

Silver nanoparticles are important antibacterial substances which are very attended to be prepared and employed in various field. This study aimed to prepare silver nanoparticles with chitosan biopolymer coating having well known adsorptive property to remove acid orange 7 dye from water. To lessen the number of experimental runs as well as to find the optimal conditions, the experimental design method was used. The performance of prepared adsorbent within the temperature range of 25-60° C, feed concentration of 8-50 mg/l, and 5-120 min contact time was examined. According to the results, the adsorption depended on dye concentration in feed solution; however, the temperature was not affecting parameter within the examined temperatures. Predictably, by increasing the contact time the dye adsorption increased and the equilibrium adsorption depended on contact time. The maximum adsorption capacity of the modified adsorbent was 37. 5mg/g. The reaction kinetic agreed with the pseudo-second-order equation and the dominant adsorption mechanism was found to be Freundlich isotherm approving chemical sorption. Silver nanoparticles offered lower dye adsorption (around 0. 15mg/g) relative to silver/chitosan nanocomposite implying the effectiveness of the applied improvement method.

Antifouling properties of mixed matrix polysulfone (PSF) and modified Halloysite NanoTube (mHNT) nanoparticles ultrafiltration membrane were studied. The membranes were fabricated with different concentrations of mHNT and PSF by phase separation method. Pure water flux, protein removal, and fouling parameters for analysis of membrane performance were studied. The HNTs nanoparticles tructure was modified by TiO2 and its structure was determined by TEM and XRD. The membrane structure was studied using Scanning Electron Microscopy (SEM). The water flux of the nanocomposite membrane was improved significantly From 140 to above 350 L / m2. h at 5bar pressure with the improved hydrophilic property. The hydrophilic properties were confirmed by measuring the contact angle and the porosity. This improvement is due to functional groups in the hydrophilic property that can be attributed mHNT and TiO2 nanoparticles. The sedimentation of the membrane, resistance was investigated by the Bovine Serum Albumin (BSA). The results of membranes with 0. 5 and 1% loading of mHNT exhibited the best anti-fouling properties which is leading to 100% flux recovery. The results also show that the membranes with 0. 5-1 wt% mHNT loading is the highest porosity and water flux.

To increase the efficiency of polymeric membranes, the surface of PES/PI polymeric blend membranes was modified by different diamines. Different diamines such as ethylenediamine (representative of aliphatic diamines, EDA), piperazine (representative of cycle diamines, PIP), and 1, 4-phenylenediamine (representative of an aromatic diamine, PPD) were exploited to change the surface properties of the membranes. The results showed a favorable rejection for EDA-modified membranes against copper ions from 35 to near 70% (nearly 100% further rejection). This parameter against lead ions was obtained from 29 to about 55%. Furthermore, the prepared membranes illustrated significant development for the removal of organic dyes. The contact angle data implied that the surface of modified membranes was changed. The physicochemical properties of the membranes were investigated with SEM, EDX, AFM, ATR-IR as well as water contact angle.

In the present research, a new dental composite based on bisphenol A-glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) containing a hydrophobic silica aerogel filler with a porosity more than 80%, the average pore size of 10 nm, and specific surface area of 811 m2/g was prepared. The effect of important processing parameters including light exposure time, the mass ratio of the resins, and preparation method on the properties of the composite was investigated. The characterization of silica aerogel and investigation of the dental composite properties were performed by FT-IR, adsorption/desorption of nitrogen, color change, and compressive strength. The results showed that the use of silica aerogel filler increases the whiteness index of the composite in comparison with the primary resin. By increasing the light exposure time to 40 s, the yellowness index of the composite was significantly decreased, while the whiteness index was increased. After that, both indexes remained constant. The compressive strength of the dental composite was increased up to 50% in the presence of aerogel particles. In addition, the composite prepared by Bis-GMA/TEGDMA with a mass ratio of 50/50 showed a higher compressive strength, due to the low viscosity of the resin which has a better penetration into the pores of the filler, in comparison with the composite prepared by a 30/70 mass ratio. The composite with a higher compressive strength was prepared by mixing silica aerogel with a more dilute monomer TEGDMA and then vacuum degassing and mixing with Bis-GMA and the initiator. The use of silica aerogel as a reinforcement of the dental resin also resulted in increasing the percentage of the cell survival and decreasing the toxicity of the prepared dental composite.

DHA fatty acid is an important omega-3 polyunsaturated fatty acid that was becoming increasingly popular in the food fortification industry due to its beneficial health effects. Having multiple double bonds in the structure of DHA fatty acid leads to oxidative degradation that produces unpleasant odor and flavor and ultimately decreases the nutritional value. The aim of this study was to develop a microencapsulation system that can be embedded DHA protecting it from adverse conditions. At first, bio-composite comprise of sodium alginate, pectin, and gelatin was prepared and the microencapsulation procedure was carried out by Ca-alginate, ionotropic-gelation method. Polymers and bio-composite were characterized using SEM, XRD, FT-IR, and TGA analysis. Based on the results, spherical and smooth micro-particles with an encapsulation efficiency of 77. 78% and process efficiency of 88. 97% were synthesized. Though, the microcapsules synthesized can be used as a new protective system and carrier in the fortified foods industry increasing the stability of DHA-rich oils.

In this study, the FeCo/rGO was synthesized by a solvothermal procedure and evaluated as the hydrogen evolution reaction (HER) electrocatalyst in alkaline media. In this sample, the percentages of iron and cobalt were varied to determine the optimized percentage of metals in the alloy. The activities of iron-cobalt alloy catalysts were evaluated by different electrochemical techniques in KOH (1M). The CV and LSV results demonstrated the best electrochemical activity of Fe0. 5Co0. 5/rGO among all investigated samples. Fe0. 5Co0. 5/rGO showed the onset overpotential of-129 mV, the overpotential of-245 mV at the current density of 10 mA/cm2, and the Tafel slope of 165 mV/dec. Also, XRD, TEM, and FT-IR techniques were employed to investigate the structure of prepared samples. The results showed the cubic phase with the nanoparticles at the dimensions of 36 nm for the synthesized of iron-cobalt alloy.

Tin catalysts are widely used in the preparation of polyurethane elastomers. dibutyltin dilaurate (DBTDL) as a tin catalyst has been used for more than 35 years in the polyurethane production industry. In this research, the synthesis of DBTDL, using dibutyltin dichloride and dibutyltin oxide was carried out at different temperatures and solvents. In all methods, lauric acid or laurate salt was used as the essential reagent to prepare laurate ligand. The results showed that among these methods, the best efficiency (95%) was obtained using two conditions of tetrahydrofuran solvent at ambient temperature (for dibutyltin dichloride) and toluene solvent at reflux temperature (for dibutyltin oxide). The chemical structure of the compound was investigated by IR, 1H-NMR, 13C-NMR, GC-MS. Finally, the infrared spectroscopy method was selected for simplicity and better accuracy to investigate the kinetics of the HTPB and IPDI reactions using a commercial and synthetic DBTDL. Using the obtained data, the reaction progress rate, reaction speed constants, and activation energy of the reaction were calculated. Activation energies for commercial DBTDL catalyst and synthetic were obtained 65. 09 and 54. 09 KJ/mol, respectively.

A one-pot synthesis of imidazole scaffolds using multi-component reactions as a highly effective methodology is presented. In this three-component reaction with the use of benzyl, aromatic aldehydes, and ammonium acetate in the presence of pectin as a green catalyst, tri-substituted imidazoles in ethanol as a solvent in high yield were prepared. In this reaction, a variety of aromatic aldehydes with electron-withdrawing and electron-donating groups have been used, and the high yields in the final products demonstrate the catalytic performance of pectin in these types of reactions. Some advantages of this method are the use of pectin as a cheap, green, and non-toxic catalyst, as well as the easy separation of products that excludes the use of chromatography for separation, as well as the high purity of the products obtained in this The type of reaction is very important.

A regioselective method for synthesis of pyrido[3, 4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3, 4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3, 4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3, 4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3, 4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3, 4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC. A regioselective method for synthesis of pyrido[3, 4-b]pyrazine derivatives were reported in high yield and short reaction times through condensation reaction between 3, 4-diaminopyridine and arylglyoxals derivatives in DMF/EtOH at 55 oC.

N-acyl hydrazones (NAH) and carbohydrazide derivatives have shown unique therapeutic properties. There is also, a growing interest in designing and evaluating the biological activity of these compounds and their derivatives to investigate their role as a novel structure in medicinal chemistry researches. Considering the importance of carbohydrazide derivatives, the indole-based structures, and isoxazole ring in drug design, The SAR of the active compounds in anti-Alzheimer, anti-cancer, and antiplatelet aggregation activity, and merits further investigation to find the optimal lead structures with maximum biological activity. In this study, the design, synthesis, and identification of the new Indole-isoxazole rings based carbohydrazides were desired. The synthesis started from 3-acetyl Indole, by using various reactants and reaction conditions (solvent, temperature), to obtain 5-(1-methyl-1-indole-3-yl) isoxazole-3-carbohydrazide as a novel compound that would be used as a fundamental structure in drug design. All structures were identified and approved at each step using spectrophotometer methods such as FT-IR, 1H NMR, and Mass.

In this study, the influence of core protonation on UV-vis, 13C NMR, and 1H NMR spectra of meso-tetra(aryl)porphyrins has been investigated. The porphyrins have meso substituents with different electron-donating abilities and a steric hindrance at the porphyrin periphery. The changes in the position of the Soret band in UV-vis spectra and chemical shift of the β carbon and protons in 13C NMR and 1H NMR spectra provide evidence on the degree of out-of-plane deformation of porphyrin core. Also, the position of the higher wavelength absorption bands (Q bands) in UV-vis spectra of the porphyrin dications depends directly on the degree of coplanarity between the meso substituents and porphyrin mean plane. Introduction of bulky methyl groups and chlorine atoms onto the ortho-position of phenyl substituents leads to a significant decrease in the saddling of porphyrin core and degree of coplanarity of meso aryl groups with the porphyrin mean plane. Concomitant use of the UV-vis and NMR spectra provide valuable information on the relative molecular flexibility of different porphyrins towards planar to saddle conformational changes upon deprotonation of the used porphyrins. Furthermore, the spectral changes can be used to compare the dihedral angles between the meso aryl groups and the macrocycle mean plane of different porphyrins.

Although anticancer properties of platinum(II) complexes have been approved, due to the hydrolysis of these complexes before arriving at the target cell, platinum(IV) complexes are generally used as an anticancer prodrug. Density Functional Theory (DFT) was employed to investigate the reduction of anticancer prodrug PtIV[Cl4(dach)] (dach = diaminocyclohexane) by monoanionic ascorbate via an inner sphere mechanism as proposed by Elding. The results obtained from the reduction by different forms of ascorbate (monomeric, dimeric, and hydrated) showed the dimer to be much more reactive. This was attributed to the one ascorbate acting as a base through partial abstraction of the proton from the other. The results were validated by performing natural bond orbital (NBO) analysis on the theoretical transition structures related to the reduction process.

Carbonic Anhydrase (CA) is an Enzyme having Zinc metal that catalyzes the reversible reaction of conversion of carbon dioxide to Bicarbonate. This Enzyme is vital for Biological systems such as the human body. In this research, the inhibitory mechanism of action of coumarin and some of its sugar derivatives with carbon anhydrase XII & II have been investigated. The most stable conformer of these Inhibitories was selected for calculations and their interaction with these two Enzymes was investigated. All calculations have been done by density functional theory (DFT) in the level of B_3LYP with basic set 6-31G* and with Minnesota function M06 with basic set 6-31+G*. In the following the thermodynamic variables of such reaction 〖 ∆ S〗 _(r×n)° , 〖 ∆ H〗 _(r×n)° , 〖 ∆ G〗 _(r×n)° have been calculated. Results show that the reaction between this family of Inhibitories and Carbonic Anhydrase Enzyme is not of the type of direct and syndetic but the Enzyme inactivates with the spacing effect.

Some chemical compounds such as the artificial colors used in various industries can have a bad effect on the health of the body. The most important biochemical molecule in the body is the DNA, that any change in its structure can affect all the living organism system. In this research for the first time, the interaction of the direct yellow 42 dye, which mainly used in the textile industry, with DNA was investigated by using Fluorescence, UV-Vis, FT-IR, and Circular Dichroism spectroscopy in the physiological buffer (pH~7. 4) and at three temperatures 298, 308, and 318 K. The results obtained from absorption spectroscopy indicated that direct yellow 42 could bind to DNA at low concentrations. Thermodynamic parameters obtained from fluorescence experiments at different temperatures showed the hydrogen bonding and van der Waals force in the binding process of this dye with DNA. The binding constant (Kb) and binding site number were calculated. The results revealed that the quenching mechanism of EtBr-DNA with dye was a static type. Finally, the structural changes of DNA due to the direct yellow 42 dye were confirmed by FT-IR results. The results of this study can present a new look at the application of colors in the industry and the risks caused by their use.

Accurate parameter estimation of non-linear mathematical models is one of the most important calculations in science and engineering. Different methods based on linearization or optimization are applied to find the parameters of the equations. In this article, a new method for parameter estimation in Langmuir adsorption isotherm has been developed. In this method, the structure of the mentioned equation was investigated similarly to the linear curve fitting method and a nonlinear single variable optimization problem was obtained. Results of Methylene blue adsorption by bentonite were used as experimental data sets and the method was compared with other linearization methods. This comparison was based on three statistical methods including Coefficient of determination, Root means square error and Normalized standard deviation, and the Langmuir isotherm parameters were considered. Compared to the linearization nature that makes errorsin mathematical calculations, the proposed nonlinear method provides better results and can be used in other similar equations.

In this work, feed-forward back-propagation Artificial Neural Networks (ANNs) have been presented to predict the enhancement of the relative thermal conductivity and viscosity of a wide range of nanofluids with different base fluids and nanoparticles. The thermal conductivity ratio of nanofluids with respect to the base fluids has been modeled using an ANN model. The model considers the effects of the thermal conductivity of the base fluid, the thermal conductivityof nanoparticles, nanoparticle volume fraction percent, temperature, and nanoparticle cluster average size. The total number of experimental data used to design the stated network is 483 from 18 different nanofluids. The (5-18-1) topology has been obtained as the best topology of the ANN model. The results of the AARD% for the train, validation, and test sets of data are 2. 6, 2. 2, and 2. 3, respectively. The viscosity ratio of the nanofluids with respect to the base fluids has been modeled using the other ANN model. The viscosity of the base fluid, density ratio of the base fluids with respect to the nanoparticle, nanoparticle volume fraction percent, temperature, and nanoparticle cluster average size have been selected as the inputs of ANN model. The 510 experimental data have been used to design the stated network. The (5-19-1) topology has been obtained as the best topology of the ANN model. The results of the AARD% for the train, validation, and test sets of data are 2. 9, 3. 1, and 3. 2, respectively. Accordingly, two studied ANN models are in good agreement with experimental data. A comparison between the predictions of the proposed ANN models and those predicted by some traditional models such as Maxwell and Bruggeman models shows that much better agreements can be obtained using the ANN model. This model also can able us to predict the relative thermal conductivity and viscosity of new nanofluids in different conditions.

Due to the special physical and chemical properties of Carbon NanoTubes (CNT), surface modification was utilized to improve the thermal characteristics of nanofluids. These techniques were done by physical and chemical modification of CNTs and utilized as a thermal fluid in plate and shell and tube heat exchangers. Polyethylene glycol (PEG) wrapping and acid treatment were respectively applied as physical and chemical procedures on the surface of CNTs to improve the dispensability of nanotubes in the base fluid. Results show the better dispersion and stability of these nanoparticles in water and consequently higher thermal conductivity of nanofluids. The thermo-physical properties of these nanofluids were applied as input variables to simulate the plate and shell and tube heat exchangers. The thermal power results of simulated heat exchangers show the higher efficiency of nanofluids compared to the base fluid. This result can be useful to enhance the thermal efficacy of heat exchangers in various industries, especially in oil, gas, and petrochemical industries.

In this paper, we present a comparative analysis of popular intermolecular forcing schemes in which their differences and similarities are identified. The results indicate that the stability of each scheme depends on three factors, density ratio, relaxation time, and reduced temperature, and it is independent of the physics of the problem. In any scheme except for Kupershtokh’ s scheme (scheme 3-b) for t/Dt ³ 1. 5 the gas density (lower density) would get larger than the critical density and the density field will diverge or get to a non-physical value. Then by fixing the relaxation time and implementing different reduced temperatures when T/T-c ³ 0. 9 implementing C-S EOS for all schemes except for the one introduced by He et al. (scheme 2-d) gas density (lower density) would get larger than the critical density and again the density field will diverge or get to a non-physical value. Variation of the physical conditions of the problem and moving the droplet from the center of the field and placing it next to the wall, wouldn’ t cause significant variation in the equilibrium density field, and this difference in equilibrium density is negligible. However, this may affect the dependence of Kupershtokh’ s scheme on relaxation time. Furthermore, the effect of forcing schemes on the contact angle between the wall and the bubble has been investigated. Results of schemes 1-a and 2-d are somehow identical and the difference between contact angle computed with these schemes and ones computed by schemes 3-a and 3-b is around 21 percent.

Dust storms are increasingly becoming one of the worst and chronic phenomena that endanger human life and the environment. Some of the detrimental impacts, but are not limited to, include inhalation diseases; cancer; and pollution of air and water resources. This, in turn, requires prompt and plausible action. Human activities that intensified the occurrence of dust storms made the present solutions ineffective to contrast with this phenomena, it is imperative to firstly get an in-depth understanding of the phenomenon in terms of mechanisms of dust movement and attachment to various surfaces. The present study endeavors solely to discern the mechanisms of movement and surface deposition and discovers the existing challenges based on previous studies. Then according to the theory of DLVO, the various adhesion forces between dust particles and deposition surfaces are calculated in different situations. The resultant findings of this study reveal that the measurement of determination of such forces is prone to uncertainty to some extent which is discussed in detail. Surface energy and humidity are the most complex factors in dust deposition.

Biodiesel is a clean and alternative fuel for diesel. It produces from renewable sources such as vegetable and animal oils. However, due to the high price of this clean fuel, it is mixed with other inexpensive fuels, such as diesel, and a fraud fuel was sold as a pure one. The purpose of this study is to evaluate an intelligent system for detecting the level of fraud in biodiesel fuels by integrating dielectric spectroscopy and image processing techniques. In order to classify fake biodiesel specimens using frequency and color properties, the principal component analysis, linear discriminant analysis, decision tree, Support vector machine, and Artificial neural network were used. The best network with structure 1-6-36 to predict blended biodiesel palm and diesel samples provided correlation coefficient and mean square error values of 0. 944 and 0. 006, respectively. In the final step, the combination of dielectric and color properties was used to model the problem. Correlation coefficient and mean squared error values for biodiesel and diesel mixed samples were 0. 962 and 0. 008 with a structure of 1-2-38. The results of the evaluations show that the designed device has the ability to detect biodiesel fuel fraud with high precision.

In the present study, the prediction of dehydrated calcium sulfate sedimentation was studied in the oil system and the presence of electrolytic solution. In this study, in order to predict the amount of sediment, two equations for activity coefficient and constant thermodynamic equilibrium have been studied. The Extended UNIQUAC activity factor model has been used to investigate and determine the calcium sulfate mineralization index. The performance of this model is desirable in electrolytic systems and its coefficients are optimized based on empirical results. The results of this study were compared to experimental data, Pitzer and NRTL models, and the result of OLI3. 2 software for the prediction of anhydrite mineral deposition. Based on the results, the total relative error of anhydrite precipitation prediction compared to the experimental results in the Extended UNIQUAC, Pitzer, and NRTL models and OLI3. 2 software are 0. 41(41%), 0. 44 (44. 72%), 0. 53 (53%), and 0. 99 (99%), respectively. Also, based on the results of the optimized model and the experimental results, the solubility of calcium sulfate precipitation in the presence of magnesium chloride and calcium chloride decreases with increasing temperature. By comparing the calculated results, it can be concluded that the proposed model has good accuracy. In this study, the pressure range was 25 to 250 bar and the temperature ranged from 1 to 300 ° C.

The water injection process and flooding for many years as one of the most important practical methods to maintain reservoir pressure and improve the flow of oil to the production wells are known. The results of the studies show that the rock composition and salinity water injection have a significant impact on flooding process efficiency. Low salinity water injection because of the availability of water and its compatibility with the environment and cheaper than other methods of injection is practical. The experimental results showed that the highest oil recovery is achieved when the concentration of salt in water injection is less than the formation water. Several mechanisms to describe the low salinity water injection for enhanced oil recovery. As stated that the migration of clay particles, changing the wettability, ion exchange, expansion of the dual-layer, changing PH, dissolved minerals, and salt effect. Interactions and interactions between mechanisms have added the complexity of understanding the exact efficiency of low salinity water injection. Although it is generally believed that low salinity water injection causes enhanced oil recovery factor, but because of inconsistencies in the results of some tests there were doubts in this regard. In addition to the low salinity water injection will be referred challenge for association studies.