Nashrieh Shimi va Mohandesi Shimi Iran
Year:2020 | Volume:39 | Issue:1 (95)|Papers Count:25

Today, polymer-based nanocomposites are used in medicine and drug delivery Non-toxic and environmentally friendly nanocomposites are very important. In this study, new polyester-based nanocomposites were prepared using silver nanoparticles, starch, and poly(diphenylsulfonyl phthalate). The structure and morphology of the new nanocomposite were investigated using FT-IR, XRD, DLS, and FE-SEM. Swelling and drug release of the new nanocomposite were determined based on different amounts of silver nanoparticles. A polymeric alloy of starch and poly(diphenylsulfonyl phthalate) had the highest swelling. Drug loading and release in nanocomposites decreased approximately with the increasing amount of silver nanoparticles.

In this study, cubic nanocrystallites of silver nanoparticles were synthesized by the nano photosynthesis method with the utilization of the secondary metabolite of black hawthorn (Crataegus melanocarpa) leaf methanolic extract. The structure and optical properties of the obtained nanoparticles were investigated by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-Ray Diffractometry (XRD), Fourier Transform InfraRed (FT-IR), and UltraViolet-Visible (UV/Vis) spectroscopy. Antibacterial effect of produced silver nanocrystallites as separately and in combined with tetracycline against four Gram-positive and Gram-negative bacterial species were studied according to the disk diffusion method. The biological study showed that these silver nanoparticles obtained by the nano photosynthesis method have good affectivity against the growth of bacteria and enhances the antibacterial effect of tetracycline as an antibiotic. Increasing the inhibition of bacterial growth by these nanocrystals was attributed to their cubic structure. Also, the nano photosynthesis method for nanoparticle preparation is an economical, fast, eco-friendly, and green synthesis method and provides optimal conditions for nanoparticle production.

Synthesis of nanostructured CoAl2O4 particles was performed successfully by a one-step < /em> solid-state method using CoCl2, AlCl3, and Al(NO3)3. 9H2O raw materials at stoichiometric 1: 2 Co: Al molar ratio. The reactions were performed at 700, 800, and 900 ᵒ C for 10 h. The synthesized materials were characterized by Powder X-Ray Diffraction (PXRD) technique. The results showed that the patterns had a main CoAl2O4 structure with a space group and the lattice parameter of a=b=c=8. 1005 Å . The PXRD data revealed that increasing the reaction temperature to 900 º C decreased the crystallite size of the target. FESEM images showed that the synthesized CoAl2O4 particles had mono-shaped sphere morphologies. The data indicated that when aluminum nitrate was used as the raw material, a light blue color was obtained. So, in the synthesis of the cobalt aluminate materials, changing the reaction temperature and raw material type affect considerably the color of the synthesized material. UltraViolet-Visible spectrum analysis showed that the nanostructured BaCeO3 powders possessed strong light absorption properties in the ultraviolet-visible light region. The direct optical band gaps were in the ranges 1. 82-1. 87 eV.

Different methods have been reported for the preparation of CuO nanoparticles with different sizes and shapes in the literature. One of them that has recently been gained considerable attention because of the high pure and perfect structure products, is the pyrolysis of copper complexes containing organic ligands. So, in this work, at first, two new precursors, CuL1 and CuL2, were synthesized by the reaction of Cu(CH3COO)2. H2O with azo-azomethine derivatives, H2L1 and H2L2, and characterized with several techniques. The results indicated that the ligands are bound to the Cu(II) ion center as anionic and tetradentate with N and O donor atoms. In the next step, CuO nanoparticles were synthesized from pyrolysis of the mentioned precursors at 550 º C for 24h. The synthesized nanoparticles were characterized and studied with several techniques such as FT-IR spectroscopy, powder X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The investigation of diffraction patterns indicated the single-phase CuO system with a monoclinic structure for nanoparticles. Also, the comparison of diffraction patterns showed that the CuO nanoparticles obtained from CuL2 have higher crystallinity. Finally, SEM images showed that the shape of CuO nanoparticles obtained from CuL1 is spherical, while the shape of CuO nanoparticles obtained from CuL2 is cubic. In addition, CuO nanoparticles obtained from CuL2 have a smaller size. These nanoparticles show a high tendency for aggregation.

One of the common methods in the size reduction of heat transfer equipment is increasing the convective heat transfer coefficient of the base fluid. The main aim of this study is to produce hydrophilic graphene and investigating its potential in the improvement of convective heat transfer coefficient in water/ethylene glycol system in the cooling cycle. Graphene was synthesized via electrochemical methods and its stability in the water was enhanced via the loading of silica nanoparticles. The synthesized graphene was investigated via FT-IR and XRD analysis and SEM and TEM images and its successful fabrication was confirmed. The different weight percent of synthesized graphene-silica including 0. 25, 0. 5, 0. 75, 1, 1. 5% were added to water/ethylene glycol fluid to investigate the improvement of convective heat transfer coefficient with this nanofluid in an experimental designed setup. The obtained experimental data for Nusselt number and pressure drop for pure water fluid was compared with those calculated via the available models and it was found that the system is able to predict the results. The setup was examined with nanofluid with different concentrations of graphene/silica and it was found that by adding 1 wt. % nanoparticle into the based fluid the convective heat transfer coefficient improved at least 40% while the pressure drop showed about 30% increment. Overall, the findings of the current study support the potential of water/ethylene glycol/graphene-silica nanofluid for use in heat transfer equipment.

In this work, the structural and electronic properties of Mercury Telluride (HgTe) in the stable zinc blend phase and high-pressure phases such as hexagonal, rocksalt, orthorhombic, and CSCl have been investigated. The calculations have been performed with the pseudopotential method in the density functional theory framework by using the Quantum-Espresso package. In order to investigate the effect of spin-orbit coupling, full relativistic calculations were performed in the ZincBlend and hexagonal phases. Energy-Volume curves indicate that the HgTe compound makes the transition from stable ZincBlend phase to hexagonal phase, as the pressure increased and Further increase in pressure leads to a transition to the rocksalt, orthorhombic, and CsCl structural phases, respectively. The calculations of band structure show that this compound is a semiconductor with zero bandgaps in the stable ZincBlend phase and indirect bandgap in the Hexagonal phase. Furthermore, by some calculations, the electronic properties of high-pressure rocksalt, orthorhombic, and CsCl phases are revealed to have metallic characters. The electronic density plot of mercury telluride shows the presence of strong covalent bonds among atoms of this compound.

Zinc-65 radioactive source was produced for medicine, agriculture, and industrial applications in Nuclear Science and Technology Research Institute. According to available facilities, 65Cu(p, n)65Zn reaction was applied. The incident proton beam energy was obtained via Alice 91 and Talys 1. 0 nuclear codes and Srim-2012 code was used for the determination of target thickness. Considering the obtained results, a 190 μ m target was bombarded with a 150 μ A current of 29. 8 MeV proton beam for 7 hours. Finally, zinc-65 was separated with chemical methods based on the ion-exchange chromatography method and zinc-65 radioactive sources with radioactivity of 402 µ Ci were produced.

Recently, developments of the energetic sources attracted lots of attention since of its great importance. In this regard looking for the new generation of light sources is quite vital. OLED is one the best light sources which have great advantages, thus it has been a hot research topic now a day, especially to find the best material increasing its efficiency. Although the research topic is quite important, the required technology for is experimental study is significantly expensive. In this paper, we have presented a nice DFT-based theoretical method applicable for studying the efficacy of guest materials in OLED systems.

It is well known that asphaltene molecules play a significant role in stabilizing the emulsion of water and oil. Molecular dynamics simulation was employed to investigate the aggregation and orientation behaviors of asphaltene molecules in a vacuum, toluene, and water interface. It was found that the simulation results have a good agreement with available data. In order to investigate the effect of asphaltene structures on the self-assembled behavior of them, six different types of asphaltene structures are selected which are different in the terms of molecular weight, carbon-chain size, and heteroatoms in the asphaltene structure. At first, the behavior of asphaltene molecules was studied purely and it was found that the hydrogen bond plays a significant role in asphaltene molecule aggregation. In addition, the interfacial tension results show that the presence of OH and NH groups, as well as hetero atoms in the asphaltene molecules, cause they have hydrogen bonding with water molecules, so the interfacial tension compare to the pure toluene reduces. But on the other hand, if the asphaltene molecules do not have any O and N atoms, they have little tendency to be present at the water surface and they were dispersed inside the toluene solvent.

The screen-printed technique is widely used as an efficient tool for electrochemical analysis in the environment, clinical, and food samples. In the present work, we have reported a simple and low-cost protocol for simultaneous determination of dopamine and uric acid using immobilization of Magnetic Core-Shell manganese ferrite NanoParticles (MCSNP) onto Screen-Printed Electrode (SPE). Also, the electroanalytical sensing of dopamine was explored at modified SPEs. The response of the modified electrode is linear in the concentration range 1. 0 – 275. 0 μ M and a date action limit of 0. 2 μ M was achieved. The proposed method was successfully employed to detect dopamine and uric acid in serum and human urine samples.

Since monitoring of drug metabolism and drug quality control plays an important role in human health, the development of easy, correct, and sensitive methods for the detection of active ingredients is important. Different methods have been developed for measuring dopamine in biological samples. In this study, a Screen Printed Electrode (SPE) modified with manganese dioxide nanorods (MnO2) was used as a simple and high sensitive sensor for detecting and measuring dopamine in real samples. The electrochemical behavior of dopamine at SPE was studied using cyclic voltammetry, differential pulse voltammetry, and chronoamperometry. In addition, by using the differential pulse voltammetry method, the calibration curve was obtained at a concentration range of 1. 0-0. 900 μ m with a detection limit of 0. 1 μ m.

A molecularly imprinted polymer (MIP) for the determination of Phenylephrine hydrochloride (PHE) was present. The MIP was prepared by electropolymerization using 1, 4-phenylenediamine (PE) as the functional monomer, PHE as the template. The imprinting effect was verified by comparing the electrochemical response of MIP and none imprinted polymer (NIP) tested by cyclic voltammetry between-0. 6 and 0. 8 V and scan rate 50 mV/s in redox peak currents of hexacyanoferrate as a probe. Some parameters affecting sensor response were optimized and then a calibration curve plotted. A dynamic linear range of 5 to110 µ M was obtained. The detection limit was 0. 9 µ M (S/N=3). This imprinted electrochemical sensor was used successfully for PHE determination in real samples.

Nowadays the production of metallic and dielectric layers has found numerous applications, an effective way for the deposition of refractory material like aluminum oxide, titanium oxide, and silicon oxide is the use of hot plasma jet. We try in this paper, after a short description of the designed plasma torch to present the preliminary results obtained by its application in alumina deposition using oxygen and nitrogen as the working gases. Surface morphology studies and also XRD patterns both confirm the formation of alumina thin films in micro and nanoscales. In this article, the characteristics of gamma-alumina nanopowder coating on two types of stainless steel and Pyrex glass substrates by plasma spray method are investigated. Morphological characteristics and phase changes of alumina deposited on two different types of substrates are studied by investigating the scanning electron microscope patterns and also X-ray diffraction spectrum. The results show that the phase of alumina is changed from gamma to alpha due to the high temperature of the plasma torch. Also, the amount of particles deposition on the steel substrate is more than the glass case.

In this study, the melting temperature of ionic liquids based on bis(trifluoromethylsulfonyl)imide anion using experimental data were modeled using the QSPR approach. The structures of ionic liquids were drawn by Avogadro software and their 3D structure were optimized by Merck molecular force field. Descriptors were calculated using Dragon and Padel software. After reducing the number of descriptors, the ionic liquids were divided into training and test set employing Kenard-Stone algorithm. For choosing the best set of descriptors, a genetic algorithm with Friedman's lack of fitness was used. Then, the numbers of optimized variables were determined by the multiple linear regression MLR method and the linear equation between variables was obtained. Linear and nonlinear models were built by means of Multiple Linear Regressions (MLR), MultiLayer Perceptron (MLP) neural networks, and using genetic algorithm. R2, AARD values were 0. 787, 0. 043 for linear model and 0. 785, 0. 0428, for nonlinear model. Both models showed the same accuracy. The applicability domain of the proposed models was also determined. Also using the obtained descriptors, the effect of molecular structure on the physical properties such as melting temperature was addressed.

Motor oils have different physicochemical properties, namely viscosity, viscosity index, flash point, pour point, etc. Viscosity is one of the important properties of motor oils since all the properties of industrial lubricants are referred to as their viscosities. The changes in viscosity with variation in temperature are regarded as the viscosity index. The greater the viscosity index, the lower the chances of the viscosity of motor oil with temperature and vice versa. According to the importance of viscosity index in lubricants and because the viscosity index of lubricants is dependent on the chemical composition of motor oils, thus in this study, a simple spectroscopic technique like Fourier Transform InfraRed (FT-IR) spectroscopy was used to analyze the Behran motor oils. The important wavenumbers that affect the viscosity indices were identified by using the Genetic Algorithm (GA) as a variable selection method. By using this method, some functional groups like Alkyl halides, Alkene, Nitro, Acid, Alkane, Alkyne, and Alcohol were recognized that affect the viscosity index of motor oils. Modeling the viscosity index of motor oils was done by Multivariate Linear Regression (MLR) method. Various data preprocessing techniques like Mean Centering and Auto-scaling were operated before the MLR and GA-MLR techniques. The results of modeling were evaluated by using different parameters like regression coefficients (R2) and Root Mean Square Error (RMSE). The values of R2 and RMSE, obtained by the GA-MLR were 0. 998 and 0. 954 respectively.

Preparation of a modified process specification is a key factor to reduce the process costs, especially in membrane water purification processes. The feed pressure is one of the most important operating parameters in this case. The aim of the present study is to investigate nitrate removal from underground water using nanofiltration (NF) membranes. In this regard, the optimum operating parameters of two FilmTech made commercial nanofiltration membranes, NF90 and NF270 have been defined. Verberne's economical model has been used to find the optimum operating parameters. The obtained results revealed higher nitrate rejection (about more than 30%) of NF90 in comparison to NF270, while its water flow rate was about half of NF270. The obtained optimum feed pressure for NF90 and NF27 were 8 and 6 bar respectively. In optimum operating conditions, the water purification cost was obtained 0. 144 USD and 0. 12 USD for NF90 and NF270 respectively.

In this research, the effect of blending polyvinylchloride/polyethylene glycol on Physico-chemical and separation characteristics of heterogeneous cation exchange membranes was studied. Heterogeneous cation exchange membranes were prepared by using the phase inversion method through the solution casting technique. Obtained results showed that membrane water content and surface hydrophilicity were enhanced by an increase of PEG ratio in the membrane matrix. The membrane ion exchange capacity, charge density, membrane potential, transport number, and selectivity initially were improved by the use of PEG concentration up to 4 %wt in membrane matrix and then began to decrease by more PEG ratio from 4 to 16 %wt. The membrane ionic permeability and flux were enhanced initially by an increase of PEG content ratio up to 2 %wt in membrane matrix and then showed decreasing trend by more PEG loading ratio from 2 to 8 %wt. The ionic permeability and flux were enhanced again by more increase of PEG concentration from 8 to 16 %wt. The membrane areal electrical resistance was decreased sharply by the use of PEG in the membrane matrix. The membrane transport number and selectivity were also increased by an increase in electrolyte concentration. Membrane showed higher transport number and selectivity at neutral pH compared to other pH values. Results show that the modified membrane in this study is comparable with that of commercial membranes.

In this paper, the effect of Vapor-Induced Phase Separation (VIPS) time on the morphology and performance of poly (phenyl sulfone) membranes was investigated. 14 wt. % dope solutions were employed for membrane fabrication. After casting the solution, the formed polymeric film was exposed to humid air for certain times to form a porous structure. Morphology and performance of membranes were characterized by Scanning Electron Microscopy (SEM), pore size distribution, pure water flux, and Bovine Serum Albumin (BSA) retention. Pore size distribution results showed that by an increase in VIPS time, the pore size of the membrane was increased, and SEM images showed that with increasing VIPS time, the thickness of the dense skin top layer decreased, also the surface of the membranes at first became smooth and then changed to rough. Moreover, by increasing the VIPS time, the pure water flux of the prepared membranes increased from 17. 12 to 37. 61 L/m² . h. The performance of the fabricated membranes for retention of BSA indicated that with increasing the VIPS time, the retention of BSA decreased gradually from 71. 3 to 52. 3% but the flux increased more sharply from 6. 94 to 17. 36 L/m² . h. Generally, vapor induced phase separation technique is an effective method that could be applied for fabricating membranes with different characteristics for different applications from one dope solution. If a membrane with antifouling features is required, low VIPS time should be applied and if a high flux membrane is desirable, high VIPS time should be employed.

Hydroxyl-terminated polybutadiene (HTPB) has been widely used as a binder for energetic composites. This neutral binder contains 10 to 15% by weight of these compounds, which if energized, increase the energy content and maintain the physical and chemical properties of the original HTPB to a large extent. The binding of Nitro to the main chain of HTPB (nitration) is a good way to energize it. Nitration common methods, such as nitration with a mixture of acids, dinitrogen pentoxide, and nitromercuration-demercuration, have led to the destruction of the backbone of the polymer. In this research, Nitration with nitrile iodide reagent has been used for the functionalization of HTPB with nitro groups, in which the double bonds and the backbone of resin are not degraded. In order to maintain the unique physical and chemical properties of HTPB, nitration levels are limited to 10 to 15% of double bonds. The purpose of this research was to investigate the effect of HTPB resin structure and the ratio of reactants used on the HTPB nitration process. For this purpose, four samples of nitrated Hydroxyl-terminated polybutadiene (Nitro-HTPB) were synthesized from two different types of HTPB with different characteristics and using two different proportions of the reactants. Then, samples were characterized by FT-IR and 1HNMR tests, and parameters such as percentage of nitration, microstructure, and their rheological behavior were compared. The results showed that the nitration rate of the synthetic samples was influenced by the ratio of the reactant used and the percentage of trans-microstructure of the initial HTPB resin. Also, samples with higher nitration content have higher viscosity and less pot life. Considering all the parameters, it can be claimed that NHA1 resin with 12. 2% nitro content among synthesized resins (among 3. 1, 4. 1, 12. 2, and 17. 6%) has the potential to be used as a binder in energetic composites.

In this research, a film model, considering forward mixing for the prediction of mass transfer behavior of a pulsed sieve-plate extraction column was applied. For modeling the column hydrodynamic, a dynamic droplet population balance model (DPBM) has been used. The model equations, including disperse phase droplet and partial differential equations, were solved simultaneously using central differential and method of lines methods. The model was studied with water-ethyl acetate as a working system. The mean drop size and its distribution (in both volume and number) were calculated by the model. The model error for mean drop size is 0. 65 % whereas the error of the correlation model for the same data is 8. 36 %. The exact modeling of the column applying droplet size variations by droplet mass balance during the extraction column showed that the model has good agreement with experimental data.

In this paper, the recycling of silver metal from computer circuit board scraps was investigated by the pyrometallurgy method. In this method, firstly, the computer circuit board scraps were mechanically crushed by a jaw crusher and then were pulverized according to the vibratory of the disc mill machine. In the next step, the sample was melted by charging material. The choice of charging materials for the production of low slag and the formation of the lead-gold-silver alloy was very important, and among the charge materials, carbon materials due to ash and the effect of various oxides of its elements on the efficiency of extraction and production of slag were investigated. In this study, various carbon materials such as gas coke, iron melting metallurgy coke, semi-coke, coal, and charcoal were studied. As a result, the semi-coke was selected for higher fixed carbon (84. 87%) and ash (8. 97%) and also less aluminum oxide (11. 87 %) in the ash, then the amount of its optimum value was 6 g. Also in this study, charcoal because of high ash (14. 20 %) and tin oxide in its ash (3. 54 %) has the lowest extraction efficiency (65%) and the highest amount of slag (45%). In the next stage, the lead-gold-silver alloy was separated from the slag phase on the basis of a large difference in the mass volume of the slag phase. Then the silver metal was separated from the gold by the parting process. Finally, the silver was extracted by the process of cementation. In this method, extraction efficiency was reported to be 94%.

Pyrolysis is a simple process to convert lignocellulose biomass into hydrocarbon fuels. The aim of this study is to investigate the effect of wood type on green gas emission. For this aim, five types of different woods were selected and pyrolyzed at 500° C. A lab-scale set-up with a capacity of 6 g biomass was used. The results showed that the amount and composition of the products are different when the wood type changed. Pinewood had the highest gas production yield (34 wt%), while the tree of heaven showed the minimum gas yield (18 wt%). Moreover, the maximum tar yield was obtained for pine wood (23 wt%). Poplar produced the lowest amount of tar (16 wt%). In addition, the minimum char was achieved from the pyrolysis of pine wood (20 wt%). However, poplar resulted in the highest yield of char. The maximum yield of CO2 was observed in the pyrolysis of pine. From the gas analysis, it can be concluded that the pyrolysis of different woods can produce a significant amount of green gas resulting in the speeding up of world global warming. The tar analysis showed that big aromatic compounds were produced from lignin in the wood structure. Furthermore, pinewood had the highest conversion amount of cellulose and hemicellulose into sugars.

Ethylene Carbonate (EC) was selected as a new solvent in order to establish a rapid liquefaction technique converting lignocellulosic waste into useful chemicals. Beechwood sawdust was liquefied by using Ethylene Carbonate (EC) as a solvent and sulfuric acid as a catalyst at high temperatures (110-160° C) and at three times (20, 40, 60 minutes) for the preparation of suitable polyol. After the liquefaction process at different temperatures and times and investigation of characterization of hydroxyl number, acid number, and yield of polyol were seen that the temperature of 130° C was an appropriate temperature for the production of polyol. Then in order to determine the appropriate time for producing the polyol at this temperature, the liquefaction process was continued at different times (40, 60, 90, 120, and 180 min) which as a result 120 minutes being selected as an appropriate time for the preparation of polyol. Also, the results showed that with increasing the temperature and time of liquefaction, the acid number and yield, and viscosity were increased, but hydroxyl number was reduced. The FTIR spectroscopy analysis showed the existence of the hydroxyl groups (OH) in the liquefied Beech sawdust (polyol) and confirmed that wood sawdust is a source of bio polyols. Also, it can be concluded that bio polyol is suitable for the preparation of polymeric products, including polyurethane adhesive. Statistical analysis showed that variation of hydroxyl and acid number, yield, and viscosity have a significant difference with increasing at temperature and time.

Limited fossil fuel resources and increasing need for fuel, air pollution and the need for green fuels have led to bioethanol being considered as a renewable energy source. This fuel is mainly produced from plants and crops. In order to determine the effective parameters on the production of fermentable sugar, dilute acid hydrolysis of Poplar waste in the bioethanol process has been used as a surface response method and central composite design. The wood was first washed with distilled water and dried in air and sunlight, ground by a vibrating disc grinder up to 50 μ m and stored in zipped plastics in room air and then hydrolyzed at certain temperatures in an acidic solution in an autoclave. To investigate the effect of the three main variables of acid concentration, temperature, and time on the fermentable sugar produced, temperature at 3 levels of 140, 160, and 180 ° C acid concentration at 3 levels of 0. 5, 1, and 1. 5% and time in 3 levels of 5, 10, and 15 min were selected. By using Molisch, Barford, and Resorcinol quality tests, the major constituents of the refined product were identified as glucose. Glucose concentration was measured using the line anion method and modeled by a two-squared equation. The results showed that in the defined range glucose production was affected by the second power of temperature and then the concentration of acid and to a small extent is affected by time. At high temperatures and concentrations of acid and medium time, most of the glucose products can be produced.

In this research, the concentration of the enzyme in a spherical immobilized biocatalyst through the reaction-diffusion equation has been investigated. The Michaelis-Menten type was utilized for the kinetic mechanism of enzyme reaction. The obtained equation is a second-order nonlinear ordinary differential equation (ODE) with variable coefficients. So, the Homotopy Perturbation Method (HPM) and Third Approximation Method were utilized as semi-analytical methods to solve the reaction-diffusion equation. Besides, the obtained ordinary differential equation is also solved by numerical method. The profiles of dimensionless substrate concentration and effectiveness factor versus dimensionless distance of biocatalyst for different values of Michaelis-Menten constant and Thiele Modulus were obtained. Then, the amount of deviation from numerical solution for each approximation method has been analyzed. The results show that the Third Approximation Method only in high values of Michaelis-Menten constant and low values of Thiele modulus has good agreement with the numerical method, while the HPM has a great match with the numerical method in all values of Michaelis-Menten constant and Thiele Modulus. Moreover, the effectiveness factor has been analyzed by HPM and it has been found that appropriate conditions for a high-value effectiveness factor are and. The HPM and Third Approximation Method results on two types of real and laboratory catalysts have also been compared with real data, the results show that HPM has more accurate and better results than the Third Approximation Method. Finally, the HPM has been used for analyzing dimensionless substrate concentration of different geometries of biocatalysts including spherical, cylindrical, and slab catalysts.