Iranian Journal of Chemistry and Chemical Engineering
Volume:42 Issue: 9, Sep 2023

Nano-structures of Cobalt Metal-Organic Complex (Co-MOC), [Co(NCS)2(L)(H2O)2.3(L)] {1} (L=2,5-dimethyl pyrazine), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or nano-sized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), FT-IR spectroscopy, and elemental analyses. Single crystal X-ray analyses on 1 display that Co2+ ions are 6-coordinated and 0D coordination complex and two organic ligands (L) are not coordinated to Co(II) in the crystal lattice. Moreover, the impacts of the following parameters were investigated: ultrasonic power, reaction temperature, and reactant concentrations on structural and morphological features of the obtained materials. In the following step, the size of the nanomaterials was investigated based on SEM images. Finally, the intermolecular interaction of molecular crystals of 1 was also studied by Hirshfeld surface analysis.

This study reports the green synthesis and eco-friendly preparation of the magnetite nanoparticles (Fe3O4 NPs) using an aqueous extract of Qazwan (Pistacia atlantica) seeds as natural stabilizers and capping agents. The green Fe3O4 NPs were characterized with different characterization techniques such as Ultraviolet-Visible (UV-vis) Spectrometry, Energy Dispersive X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM) Equipped with Energy Dispersive Spectroscopy (EDX), and Fourier Transform InfraRed (FT-IR) spectrophotometry. The UV-Vis spectrum and FT-IR were used to identify the biomolecules in the Qazwan seeds extract for green synthesized Fe3O4 NPs. The XRD, TEM, and SEM demonstrated the generation of  Fe3O4 NPs with an average diameter of 14-15 nm. The Williamson-Hall and the Scherrer equation obtained the crystalline size for Fe3O4 NPs, respectively, 6.43 and 14.22 nm which confirmed the effects of both crystallite size and strain. Additionally, the antibacterial and antifungal activity of synthesized Fe3O4 NPs was tested, which revealed that NPs had moderate antimicrobial activity against gram-positive bacteria (Enterococcus faecalis), gram-negative bacteria (E. coli, Pseudomonas aeruginosa, Acinetobacter baumanni, and Klebsiella pneumonia) and Candida albicans pathogenic fungal strains at different concentrations of Fe3O4 NPs (1.0 to 20 mg/mL) with average inhabitation zone of (8 to 22 mm).

In this study, a novel bicomponent nanomaterial has been designed to be used as an antibacterial effective wound dressing for dry wounds. These nanofibers' wound dressing successfully have been produced by coaxial electrospinning method feeding neat polylactic acid into the core and thermoplastic polyurethane-silver nanoparticles into the shell. In addition to examining the antibacterial and cytotoxicity properties of the designed polymeric nanomaterials, physical and chemical characterization studies have been also carried out. It has been determined that the 10% silver nanoparticles doped bicomponent nanomaterial had the thinnest smooth nanofibers with 1127 nm value, the highest hydrophobic behavior with 131° contact angle value, the highest tensile strength with 2.53 MPa value, and the highest flexibility with 66.84% value. In addition, 10% and 5% silver nanoparticles doped bicomponent nanofibers have been indicated to have high cell viability with values of about 90% and 80% respectively. It has been emphasized that these bicomponent electrospun mats, which have been improved for dry wounds can be used as a 100% antibacterial effective wound dressing against escherichia coli, staphylococcus aureus, and pseudomonas aeruginosa if it is renewed every 24 hours.

In this study, Pine Pollen (PP) was introduced into the structure of sodium montmorillonite (Na+-MMT), and then these new nanoparticles (PP-MMT) were added to the epoxy resin (EP), and new nanocomposites were prepared. The results of the PP-MMT investigation confirmed the presence of PP in the structure. The results of polarization and salt spray tests showed that the presence of PP-MMT in the matrix improves corrosion resistance, so the coating containing 1.5wt. % PP-MMT showed an inhibition efficiency of about 87%. The storage module (E') for EP was 2170 MPa, which increases with increasing PP-MMT content up to 2350 MPa, also the effect of PP-MMT on the glass transition temperature (Tg) was up to 2.5 °C. Also, the strength and Young’s modulus increased up to 13 and 126 MPa, respectively. Moreover, the antimicrobial results showed that the presence of PP-MMT made the nanocomposite effective against Bacillus subtilis, Staphylococcus epidermidis, Escherichia coli, and Shigella dysenteriae.

Flotation is a justifiable way to isolate valuable particles from primary ore. Collectors make mineral-rich particles connect to the froth phase and separate them in the flotation column. In this work, sodium dodecyl sulfate-modified nano Alumina as a new co-collector has been applied in the flotation process to boost the recovery of copper from oxide sources. For this purpose, the first nano alumina has been prepared by chemical precipitation method. co-collectors are some nanoparticles that have the potential to improve flotation performance in the recovery of valuable elements. The present study aims to produce spherical gamma-alumina nanoparticles and evaluate them as co-collectors to increase the flotation recovery of a natural sulfide-oxide copper mineral along with the molecular collector of Potassium Amyl Xanthate (PAX). morphology and structure of nano alumina were investigated by Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD). The flotation recovery for acidic and alkaline nanoparticles was 86.65% and 93.15%, respectively. In comparison, in the absence of nanoparticles, the flotation number degraded to 53.35%. Moreover, the effect of nanoparticle dosage was investigated in this study.

Heavy metal pollution in aquatic environments has increased significantly in the last few decades. Therefore, different technologies have been used to deal with this problem. In these technologies, different adsorbents are used to adsorb and separate heavy metals from the aqueous medium. In this regard, the use of new technologies such as nanomaterial technology which uses nanomaterials as adsorbents with the potential for adsorption capacity and fast recovery and low cost, especially magnetite nanoparticle adsorbents, has provided efficient and cost-effective solutions for the extraction and removal of heavy metals from water. In the present study, the separation of vanadium (V) in an aqueous medium was studied using an adsorbent of magnetite nanoparticles that was successfully synthesized by the co-precipitation method. The synthesized nanoparticles were tested without functionalization to remove vanadium. The maximum adsorption percentage of vanadium by non-functionalized magnetite nanoparticles was 99.6 percent in optimum conditions: pH equal to 3.5, at ambient temperature (20 °C), contact time 30 minutes, 5000 mg/L adsorbent amount, and 50 mg/L initial concentration of vanadium (V). The Langmuir, Freundlich, and Temkin isotherm models were evaluated for the vanadium adsorption process. It was observed that the Langmuir isotherm fitted better onto the laboratory data than other models. The kinetics of the experiment showed that the data obtained were more consistent with the pseudo-second-order kinetic model.

Diclofenac batch adsorption was investigated in a synthesized aqueous solution using Activated Carbons (ACs) prepared from walnut shells with the chemical activation method. The use of phosphoric acid as an activating agent for preparing of ACs has been studied. The ACs were yielded  at various concentrations 20,35,40,60,75 and 85%, respectively, which are termed AC20, AC35, AC40, AC60, AC75 and AC85%. Adsorbent was characterized for its texture by Scanning Electron Microscopy, Granulomere laser, Interferometric Microscopy, X-ray diffraction and Fourier transform infrared spectroscopy-Attenuated total reflectance. The structure is determined by the iodine and methylene blue number, point of zero charge measurement and optimization of diclofenac adsorption parameters. Adsorption tests determined the adsorbate were performed on diclofenac sodium by varying the mass of ACs, pHi, initial concentration, stirring speed, contact time and temperature. The limits of pharmaceutical substance adsorption by prepared ACs were    99.66% with AC35% at pH= 2, m35% = 2mg, at contact time of 60min for diclofenac sodium. The synthesis results showed that the optimal physicochemical properties of the ACs were observed at 25°C, and the optimal iodine and methylene blue adsorption of AC35% was 3784.6 mg/g and 1990.67 mg/g, respectively. It was observed that the removal efficiency of Diclofenac sodium (DCF) was defined by the reactivity with the adsorbent and the percentage of activating agent. The ACs elaborate are an excellent adsorbent for the removal of the pharmaceutical substance studied.

In this study entacapone, levodopa, and carbidopa, were determined with high precision in the presence of each other. UV-VIS spectroscopy was used as an easy and low-cost technique for the analysis and the derivative spectrophotometric method was applied for elimination of absorption interferences. For this purpose, the derivative spectra of each compound were studied separately, and zero crossing points were determined for each of them. The zero-crossing points in which the absorption was observed only for one compound were found and evaluated for quantitative analysis. Calibration curves were drawn from the second and third derivative signals for each compound and the linear range was determined. The method was linear in the range of 1-5 µg/mL for levodopa, 0.25-1.7 µg/mL for carbidopa, and 2-14 µg/mL for entacapone. The accuracy and precision of the proposed method were evaluated by within-day and between-day tests (CV < 1.56% and error < 1.7%) and finally, these drugs were determined in pharmaceutical dosage forms by the developed method.

Multi heterocyclic ring system shows a wide spectrum of pharmaceutical and biological activities. Novel series of 2-Benzyloxy-5-(2-{N'-[3-(substituted-phenyl)-1-phenyl-1H-pyrazol-4-ylmethylene]-hydrazino}-thiazol-4-yl)-benzoic acid methyl ester derivatives have been synthesized by one-pot condensation of 2-Benzyloxy-5-(2-bromo-acetyl)-benzoic acid methyl ester, thiosemicarbazide and 3-(substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde using orthophosphoric acid as a catalyst under mild reaction condition. All the synthesized compounds were screened for their anti-tubercular activity against Mycobacterium tuberculosis H37Rv stains using the Lowenstein-Jensen (L. J.) medium conventional method. Most of these synthesized compounds are found to be active potent against Mycobacterium tuberculosis H37Rv strain. Environmentally benign, multicomponent, rapid, high atom and step economy, facile are the remarkable features of the present one-pot multicomponent protocol.

The formaldehyde, HCHO, is generated via the partial oxidation of methanol, and the investigation of its electrochemical oxidation is essential for the complete knowledge of methanol oxidation. Ceramic material with a spongy structure can promote the dispersion of noble metals as the main catalyst for the electrooxidation of organic molecules. In this research, spinel ZnMn2O4 (ZMO) micro-sponge was synthesized, characterized, and utilized as a booster for the Pd catalyst. Palladium was stabilized on ZMO with two different strategies, containing reduction with sodium borohydride and zinc plate. The samples were assessed using X-ray diffraction, scanning electron microscopy, transition electron microscopy, and electrochemistry. In comparison with non-promoted Pd, Pd/ZMO electrocatalyst was shown excellent efficiency in parameters like electrochemical active surface area and turnover parameters. The outcomes represented that the palladium nanoparticles are reduced with the chemical system having a lesser diameter and better dispersion than the electrochemical one. Consequently, as we expected, the electrochemical oxidation of formaldehyde showed better results for the reduction by the chemical in comparison with electrochemical reduction systems.

In this study, direct conversion of methane to methanol in the plasma process was attended. Besides, RSM modeling was used to optimize and evaluate parameters such as voltage, the flow rate of CH4, Ar, and external electrode length. RSM prediction model by the desired condition including minimized Ar (20 mL/min), O2 (2 mL/min), CH4 (2 mL/min), and voltage (4 kV) was used to determine the effect of Ar and CH4 in reactions. The results showed that increasing the Ar flow from 20 to 100 mL/min led to less methanol mole percent. On the other hand, enhancement in methane flow rate from 2 to 12 mL/min was the reason for raising the methanol mole percent at the reactor outlet. To determine how modifying the length of the external electrode affected the mole percent of methanol, the length was lowered from 12.5 to 2 cm, clearly reducing the amount of methane converted. However, it was effective in raising the methanol mole percent to 3% in E.EFF 0.13 mmole/kJ and length of electrode 4 cm. As well as the methanol mole percent in the least energy efficiency E.EFF 0.045 mmole/kJ detected at 2.27%. To summarize, in DBD plasma reactor by direct conversion of methane, increasing in voltage and Ar flow rate had a significant influence on the progress of the process which had an unfavorable effect on methanol mole percent. Meanwhile, the enhancement of CH4   flow rate had an impressive effect on the raising of methanol. Furthermore, the influence of oxygen flow was negligible.

Some of the main challenges of direct methanol fuel cell membranes are proton conduction and the high selectivity required. In the present study, new proton exchange membranes were developed using sulfonated polystyrene (SPS), polyethylene (PE), and a type of Metal-Organic Framework (MOF) used in the Direct Methanol Fuel Cells (DMFCs). MIL-53(Fe)-(COOH)2 is a metal-organic framework prepared in this study, and it was used as a filler in manufacturing the membranes. Characterization of these membranes was performed by SEM, FT-IR, and TGA. SEM images showed that the MIL-53(Fe)-(COOH)2 particles have a porous surface without any agglomeration. Also, the conductivity of proton, methanol permeability, oxidation resistance, and ion conductance tests were performed on membranes to evaluate membrane performance. The effect of MIL-53(Fe)-(COOH)2 content in membranes was also studied. The embedding of MIL-53(Fe)-(COOH)2 in SPS/PE membrane increases proton conductivity and selectivity factor. Finally, the prepared membranes were applied to the direct methanol fuel cell, and the performance of the membranes was examined. The result was a maximum peak power density of 23.61 mWcm2 with a maximum current density of 138.46 mA/cm2.

The use of lithium-ion batteries in electronic devices is growing rapidly. As a result, the demand for the consumption of lithium metal has increased. Although spent lithium-ion batteries contain sources of precious metals, they seriously threaten human health and the environment. Therefore, the recovery of lithium-ion batteries may prevent environmental pollution. The hydrometallurgy method was applied as the recovery process due to its high recovery efficiency, low energy consumption, and high reaction rate. It is widely used in the recycling process of spent lithium-ion batteries. In this research, instead of all reports concerning synthetic wastewater, industrial wastewater containing lithium was used as feed. Effective parameters on lithium recovery in the form of lithium carbonate and its purity were the initial mass of solution to final mass of solution or concentration ratio, the mole ratio of sodium carbonate to lithium sulfate, raffinate usage, and the cooling effects. Results showed that the optimum condition to achieve maximum purity and recovery of lithium carbonate was obtained at a concentration ratio of 15-20. At different tests with the mole ratio of sodium carbonate to lithium sulfate as 1, 1.5, and 2, the highest recovery efficiency was obtained at the ratio of 1.5. The use of sediment-free raffinate in the last stage also played a big role in lithium recovery. To use the raffinate solution, the raffinate must first be removed from the saturated state of sodium sulfate. Then sodium carbonate becomes saturated in raffinate and is added to the original solution. Under the above conditions, lithium carbonate was obtained with a purity of approximately 99% and a recovery of 65%. The combined process of evaporation with cooling was also a proper process for producing lithium carbonate. In this state, the purity and recovery of the final product were approximately 97% and 75%, respectively.

For the first time, the ability of a Microbial Fuel Cell (MFC) to produce value-added products from the high content of oily kitchen waste was evaluated. A Single-chamber, air-cathode MFC containing 30% solids was designed for evaluation of the rate of biohydrogen and bioelectricity production. Food wastes were studied in four states: oil-free (0%), containing 3% oil, 6%, and 9% oil during 30 days of operation. Experiments showed with increasing the amount of oil, the amount of biohydrogen produced increased from 0 to 6% of the oil, and with the addition of 9% of oil, no significant change was observed in the biohydrogen production rate. The average daily production of biohydrogen for 0, 3, 6 and 9% of the oil was estimated at 42.5, 58.7, 69.6 and 70.1 mL per day, respectively, which showed that adding oil up to 6% could increase the efficiency of the system for biohydrogen production. On the other hand, with the increase in the amount of oil, the production of bioelectricity decreased, so that the maximum output voltage was recorded for the fourth day of zero state: 472 mV, and the lowest voltage on most of the days recorded for 9% of oil. The results of Chemical Oxygen Demand (COD) removal showed with increasing the amount of oil, although the amount of initial COD increased, the amount of COD removal decreased, which is consistent with the process of electricity production. Volatile fatty acids including acetate, butyrate, and propionate were other valuable products of the system, although the accumulation of VFA was indicated as an inhibitor for biohydrogen production The results showed kitchen waste without oil separation can be used as a useful substrate in MFC systems to produce value-added products, in this way, sewage pollution by oil resulted from food waste could be prevented.

Milk desserts are semisolid and complex matrices with a proteinaceous structure containing essential ingredients like cow's milk, starch, sugar, gelatin, and flavorings. In this study, the physicochemical, sensory properties and probiotics viability of milk dessert enriched with date seed powder (0, 1.5%, and 3%) during 20 days of storage were investigated. The results indicated that acidity (14.4-26.7), dry matter (24.22%-27.77%), °Brix (22.65-24.39), ash (0.76-0.84), fat (3.61%-3.83%) and protein (3.95%-4.15%) content of milk dessert was increased in the presence of date seed powder. Adding date seed powder significantly increased the stability and viscosity of milk desserts. The viability of the Lactobacillus plantarum (L.plantarum) has improved in the presence of date seed powder; therefore, this food waste could be considered as a prebiotic component. Generally, the most acceptability of sensory evaluations was found in samples treated with 1.5% date seed powder.

Depectinized Date Juice (DDJ) was clarified with an ultrafiltration (UF) unit (containing PVDF-membrane with 30-40 nm pore sizes) and combined with an electric field (EF). The UF had 3 independent variables (temperature, pressure, and flow rate) respectively at [27 & 40oC], [1, 1.5, & 2 bar], and [10, 15, and 20 mL/s] levels. After applying a statistical tool, the optimized levels and affecting factors of temperature, pressure, and flow rate on the resulting permeate sequentially were 40°C & 55.23%, 1.5 bar & 43.01%, and 20mL/s & 1.76%. While the highest permeate flux of UF reached 2.5, it amplified to 5 Kg/m2h (100% increase) when it was joined with the EF at 5 V strength. Although UF permeate could recover 68% and 58% of the phenolic and antocyanin compounds of DDJ, the UF+EF processes improved these recoveries and reached 92% and 80%, respectively. Similarly, the sucrose and glucose in the permeate of UF+EF were at least 10% more than those obtained in the permeate of UF only. The redness color in retentates of DDJ after passing UF and UF+EF concentrated up to 213% and 292%, respectively.  Finally, the application of UF and UF+EF could eliminate the bacterial loads (Enterobacteriaceae, Escherichia coli, mold, and osmophilic yeast) of DDJ below the permissible levels. Overall, the combination of UF+EF could clarify the DDJ with richer bioactive compounds, more reducing sugar, brighter color, and lesser turbidity than those treated with UF only. It also produces a retentate with higher pectin content as a valuable source for making supplementary food.

The decline in the pressures of natural gas wells is forcing industries to either find more sustainable alternatives or temporarily make up for the shortfall. One such Pakistani gas field is the Mari Gas Field reservoir, from which the natural gas is extracted and used to produce ammonia which is the precursor of urea production. To temporarily cope with the declining pressures, this study proposes that a mixture of exported RLNG (30%) and Mari gas (70%) be used as feed. Material and Energy balances and the reactor designs were carried out and compared with the existing feed. Results showed that the proposed blend of RLNG and Mari gas could be used for ammonia production. However, alterations in the form of increased tube lengths, reactor volumes, and catalyst loading will be required in the main equipment of plants. Nevertheless, these modifications result in 20784-20791a +20.65% increase in hydrogen production, +4.53% increase in ammonia production, and +4.54% increase in urea production. Thus the proposed scheme can be adopted to manage the shortfall of Mari gas.

The problem with waste plastic is that it decomposes after hundreds of years which causes its accumulation on the land. The waste plastic is used in the production of Polymer-Coated Aggregate (PCA) material that is eventually used in the construction of commercial roads. The roads made from PCA material are more efficient and are of greater strength as compared to normal roads. Through previous extensive experimental work, it is concluded that the addition of 12% of plastic in the total mixture provides the optimum results. The chosen process for the research to make PCA is the dry process, which follows by heating the aggregate stone to a certain temperature and on the other hand melting the PCA and coating over the aggregate. This research is mainly based on the fabrication of a machine that eventually produces PCA. The process of production of PCA material includes pre-heating of crushed aggregate, shredding of plastics, melting and coating of plastics, heating bitumen, adding hot molten bitumen, and uniform mixing. The aggregate tests began with each batch sample from the machine to validate the working and product quality of the fabricated mixer. The mean of Marshall stability value, flow value, and % air void are 2651.893kN, 17, and 2.642% respectively. Whereas the mean aggregate crushing and impact value obtained is 9.778 and 7.627. The mean value of specific gravity obtained is 2.569. The produced PCA material has a low water absorption capability is 0.573. The Los Angeles abrasion test, 9.652 is the mean abrasion value observed. The mean value of the stripping test obtained is 0.197%, which shows that there is almost negligible stripping of bitumen from the surface of PCA.  It can be concluded that the fabricated rotary mixer gives us an adequate PCA product with suitable enhancement of binding properties for the pavement of roads.

Chlorination of 3-acetyl-4-methylthioquinolin-2(1H)-one (1) with sulfuryl chloride may lead to 3-(2,2-dichloroacetyl)-4-methylthioquinolin-2(1H)-one (2). Whereas analytical and spectral results  for the product of this reaction evoked the proposal of obtaining 3-chloro-4-hydroxyquinolin-2(1H)-one (3), which was found by reduction of 3,3-dichloroquinolin-2,4-dione.  Density Functional Theory (DFT) and time-dependent density functional theory (TD-DFT) calculations of the electronic structure at the B3LYP/6-311++G (d,p) level of theory were used to investigate the geometries, linear polarizability ⟨Δ𝛼⟩, first order hyperpolarizability ⟨𝛽⟩, natural bonding orbital (NBO), molecular electrostatic potential contours (MEP&ESP), electrophilicity (ω), and UV-Vis spectra, in both ethanol and dioxane solvents for compound 3. The geometrical and energetic characteristics have been thoroughly studied to determine why compound 3 was formed instead of another expected result compound 2. At the same time, the thermo-chemical parameters, NMR, harmonic vibration frequencies, and equilibrium geometries were computed. The calculated acidity constant (pKa) for the protonated and deprotonated forms in ethanol for the present compound 3. Band maxima (λmax) and spectra intensities are reflected as blue and red shifts in the solvent dependence. The excited state was identified and contributed to the electronic configurations. Finally, DFT calculations were used to connect the structure-activity relationship (SAR) with real antibacterial results for compound 3.

In the current study, the solubility and density of deferiprone were determined in the polyethylene glycol (PEG) 400 and 2-propanol mixtures at 293.2 – 313.2 K using a shake-flask method before a spectrophotometric method. The results showed that the solubility increases with both PEG 400 mass fraction and temperature increase. The measured data were fitted to some mathematical models including van’t Hoff, MRS, Jouyban-Acree, Jouyban-Acree–van’t Hoff, and the modified Wilson models. The results from the investigation of model accuracy showed that there were only tiny differences between measured data and back-calculated data from solubility values (MRD% <3.5%). Moreover, thermodynamic studies showed that the deferiprone dissolution process was endothermic and entropy-driven, and the main contributor of ΔG° was the enthalpy

The current study mainly aims to determine the flow and heat transfer from a circular vertical cylinder’s slow rotation concerning different viscous fluids bounded by a concentric vertical cylinder. The governing equations are simplified to investigate the possibility of a precise solution. Two sets of partial differential equations with nonlinear coefficients are finally obtained, which are solved using a numerical method to reach a quick result. The impacts of aspect ratio, Prandtl number (Pr), and Richardson number (Ri) are examined on the performance of fluid flow and heat transfer. The bounding cylinder’s diameter and height vary from double to quadruple of the rotating cylinder, while the Pr ranges from 55 to 5050. The Ri also varies from 0.01 to 10. The influence of flow decreases near the boundaries as the outer diameter of the boundary increases; the average Nusselt number (Nu) decreases similarly. A change in the Ri from 0.01 to 1 led to the dominance of the forced convection. At mixed convection equal to one and above, natural convection dominates. Small Ri creates vortices in the domain, which disappear by enhancing Ri. The average Nu decreases by changing the Pr number from 55 to 5050. Results are presented as the streamline, isotherms contours, and local as well as average Nu. The details of numerical investigations are compared with the literature which shows a reliable agreement.

In this paper, for the first time, a numerical code based on the Levenberg–Marquardt method is presented to solve the inverse heat transfer problem of an annular jet on a cylinder with uniform transpiration and estimate the time-dependent wall temperature using temperature distribution at a point. Also, the effect of noisy data on the final result is studied. For this purpose, the immediate task is to solve the temperature with no dimensions and convection Heat transfer in a cylinder with a radial incompressible flow numerically. The free stream is steady, and the initial strain rate of flow is . The equations of momentum and energy are transformed into semi-similar equations using similarity variables. After discretizing the new equation system using the finite difference technique, it is solved by using the tri-diagonal matrix algorithm. After that, the wall temperature is calculated throughout using the Levenberg–Marquardt approach. This is a collaborative technique aimed at minimizing the least-square summation of the error values, where the error indicates the difference between the predicted and observed temperatures. This method exhibits considerable stability for noisy input data. In most cases, surface blowing decreases the prediction accuracy by displacement of the boundary layers from the surface, whereas suction acts vice versa. The main reason for this study is that in many industrial applications, it is not possible to insert the sensor on the wall to measure the temperature of the wall the sensor can be inserted in another place and the wall temperature distribution can be obtained by inverse analysis (Determining of unknown boundary condition).

Thermal energy storage systems containing phase change materials are widely used in industry. This investigation was done to improve the heat transfer performance of the charging and discharging processes (melting/freezing cycles) for heat exchangers containing phase change materials (Paraffin wax) with Nano-particles ( ), based on the total required time to complete the charging and discharging processes during the cycle. Using the enthalpy porosity technique to analyze the phase change phenomenon during the charging and discharging processes, a numerical model has been developed to study the heat transfer performance of the cycle In contrast, the influencing parameters, such as the geometric, thermophysical, and hydraulic parameters, are changed. The study was carried out in four arrangements: a base case, a reversed chamber, and each with two flow directions. For each arrangement, the effects of the volume fraction of the Nano-particles (0, 2, and 5%) on the melting/freezing average have been studied. The results show that by changing the above parameters, the total charge and discharge cycle time of the heat exchanger improves from 101 hours to 56 hours, which means 44.5% for the inversed chamber and the direction of flow, and 5% for Nano-particles.

The present study conducted a 2-dimensional numerical simulation using the Computational Fluid Dynamics (CFD) method for a Darrieus Vertical Axis Wind Turbine (VAWT). This study aims to investigate the effect of changing design and operational parameters on the performance of the Darrieus turbine. Power coefficient and torque are calculated to observe the turbine's performance, and their values ​​are compared in the different Tip Speed Ratios (TSR) and azimuth angles, respectively. Therefore, effective parameters such as free wind velocity, chord length, blade number, and airfoil profile are investigated. The results show that increasing the inlet velocity and chord length led to an increase in the efficiency of the turbine and formation of intense wake flow around the blades; however, increasing the number of turbine blades in small TSRs shows better performance, while when the rotor rotations number increases, the low solidity turbine with a lower number of blades has more efficiency. Also, the NACA0021 airfoil profile had higher Cp than other airfoil profiles and augments the wake flow downstream. An optimization method is provided to find the optimal operating and geometric conditions to achieve a higher value of Cp. The results show that the highest efficiency of Darrieus VAWT is achieved with an inlet velocity of 12 (m/s) and blade chord length of 0.2 (m) for a three-bladed turbine at TSR=2.5. It is also shown that Darrieus VAWT operates with lift force and needs an initial torque to start working by increasing the values ​​of Cp in the primary TSRs; the turbine's need for initial torque decreases.

In this study, the effects of ethanol-butanol/gasoline blends (EB0%, EB10%, and EB20%) on spark ignition engine performance and emissions were investigated for the different compression ratios (6.0:1, 8.0:1, and 10.0:1), and different load conditions (2kW, 4kW, and 6kW). Based on the experimental results, the response surface methodology has been used to develop a model and to estimate the outputs of brake thermal efficiency, brake-specific energy consumption, carbon monoxide, hydrocarbon, and oxides of nitrogen. The optimum operating conditions, 9.970% of the ethanol-butanol blend, 10.0:1 compression ratio, and 6 kW of engine load were obtained through the desirability approach of response surface methodology. Brake thermal efficiency, brake-specific energy consumption, carbon monoxide, hydrocarbon, and oxides of nitrogen at optimum conditions are 35.041 %, 0.493 kg/kWh, 0.217 %, 213.575 ppm, and 1263.787 ppm, respectively. Moreover, the developed models have higher R2 values near 1, and the optimum responses are obtained with a higher desirability value of 0.768. Ethanol-butanol/gasoline blends improved the brake thermal efficiency, carbon monoxide, and hydrocarbons. Whereas it increased the brake-specific energy consumption and oxides of nitrogen.  In addition, the validation test results illustrate that the acceptable error rate between optimized values obtained through the desirability approach of response surface methodology and experimental values is below 7%.

Biosurfactants are used widely in the oil and petroleum industries such as the production, transportation, and storage process of oil. This application of biosurfactants is due to the biodegradability of these biomaterials. This study investigated the effect of pH on stabilized water-in-oil emulsions using rhamnolipid and saponin biosurfactants. The phase separation was determined by measuring the volume of the water phase separated. The obtained results showed the introduction of HCl significantly affects the stability of emulsions stabilized by rhamnolipid and saponin but had no significant effect on the mixture of biosurfactant contents because of the synergistic effect. Also, the results showed that the maximum separation yield for rhamnolipid, saponin, and mixed biosurfactants at pH=1 and after 1 hour of sonication was 61, 57, and 20%, respectively. The water droplet sizes of the emulsion after sonication and before phase separation at pH of 5, 3, and 1 were around 100, 200, and 1000 µm for 40–60% of w/o emulsion stabilized by the mixture of rhamnolipid and saponin biosurfactants using DLS analysis. The results demonstrate that at low pHs the dramatic instability of w/o emulsion was obtained and significantly increased the rate of the Ostwald ripening process and coalescence rate of water droplets.

A new approach in this work was the biodegradation of Benzene, Toluene, and Xylene (BTX) using Airlift Parallel Bioreactors (APB’s) connected to the Plexiglas Bio-Scrubber (PBS) Modulated with Polyurethane Foam (MPF) as modified sort in the use of mineral pumice as a porous filler Lava rock media. The aeration bioreactors were set up with a microbial consortium of refinery Sludge Effluent Sewer (SES) treatment and nutrient solution. The performance of PBS for BTX removing by APB’s filled with Activated Sludge Effluent Sewer (ASES) in the range of inlet BTX concentrations from 180.7 to 881.8 ppmv in different air pollutions flow rates was tried for two rates: 2.5 & 3.5 L/min  at 30 days Mean Residence Time Distribution (MRTD) for each treatment. The results showed that at inlet pollutant concentrations of [B] = 180.7 ppmv, [T] = 327.4 ppmv & [X] = 297.5 ppmv, the removal efficiency in flow rate 2.5 lit/min was 90.7, 88, and 83.6(%) for benzene, toluene, and xylene, respectively. The amount of removal in flow rate 2.5 lit/min was better than the removal efficiency of 3.5 lit/min due to lower pollution concentration.