SHahab Zangeneh

   One of the fundamental challenges in photovoltaic (PV) systems is the rise in panel temperature under intense solar radiation, which leads to reduced efficiency and service life. The use of phase change materials (PCM) as thermal energy storage can help reduce the surface temperature of panels. In this study, the combination of PCM with metal foams (MF) is investigated; metal foams, due to their high porosity and suitable thermal conductivity, can accelerate heat transfer and reduce PCM melting time. This research employs a computational fluid dynamics (CFD) approach to numerically simulate a PV-PCM-MF system and analyzes the effect of parameters such as metal foam porosity and geometric dimensions of the heat sink on the thermal and electrical performance of the solar panel. The main objective is to present a novel method for optimizing heat transfer and enhancing the electrical efficiency of photovoltaic systems. The results of this study are expected to demonstrate that appropriate selection of cavity geometry and optimal combination of PCM and metal foam can lead to reduced panel operating temperature, increased thermal storage capacity, and significant improvement in electrical efficiency. This research provides practical guidance for the optimal design of hybrid PV-PCM-MF systems in the field of renewable energy.

   Heavy metal contamination, particularly from nickel and chromium ions, have significant environmental and health risks due to their toxicity and persistence in water. Conventional removal methods mostly are lack of selectivity and efficiency. It pushes researchers to explore the novel adsorbents. In this study, phycocyanin-functionalized magnetic nanoparticles were prepared to selectively immobilize Ni(II) and Cr(VI) ions from aqueous solutions. Magnetic nanoparticles were first synthesized and coated with polyethyleneimine, followed by functionalization with phycocyanin to provide active binding sites for metal ions. Adsorption experiments were conducted under different conditions, such as initial metal concentration, and contact time, and removal efficiency and adsorption capacity were calculated. The adsorption kinetics were analyzed using a pseudo-second-order model, while Langmuir isotherms were applied to determine maximum adsorption capacities. Results showed rapid Ni(II) adsorption within minutes, whereas Cr(VI) uptake was slower but reached similar capacity over extended time, reflecting differences in affinity and interaction mechanisms. Maximum adsorption capacities were 13.85 mg/g for Ni(II) and 22.17 mg/g for Cr(VI), and adsorption was strongly influenced by pH, with nickel favoring alkaline conditions and chromium favoring acidic conditions. Desorption experiments showed that the adsorbent could be regenerated and reused, indicating practical applicability. FTIR analysis confirmed the presence of functional groups responsible for selective binding and the stability of phycocyanin on the magnetic core. In conclusion, the magnetic adsorbents provided selective, efficient, and reusable removal of nickel and chromium ions, suggesting a promising approach for wastewater treatment and offering a foundation for future studies to optimize performance. Keywords: Phycocyanin, Magnetic nanoparticles, Nickel, Chromium, Adsorption

  High-entropy alloys (HEAs), as advanced multicomponent systems comprising at least five principal elements with atomic concentrations ranging from 5 to 35%, have garnered significant attention in engineering research due to their outstanding mechanical, chemical, and thermodynamic properties. Although the fabrication of these alloys has predominantly been investigated in bulk form, limited studies have explored their synthesis as thin-film coatings. In this study, a CoCrNiCuZn high-entropy alloy coating was synthesized via direct current (DC) electrochemical deposition in a chloride-based electrolyte onto a 304 stainless steel substrate. The deposition parameters were systematically examined to analyze the coating’s morphology, chemical composition, and crystallographic structure. Characterization was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and grazing incidence X-ray diffraction (GIXRD). The results indicated that under constant current conditions, the synthesized coating exhibited a smooth, dense, and crack-free surface. Thermodynamic calculations using the HEAPS software predicted the formation of a solid solution phase with a face-centered cubic (FCC) structure, which was consistent with the GIXRD data. The agreement between experimental observations and thermodynamic predictions validated the accuracy of the modeling approach. Corrosion resistance evaluation revealed that the CoCrNiCuZn coating possessed favorable anti-corrosive properties. The sample with a corrosion current density of 3.07 µA/cm² and a corrosion rate of 1.31 mpy was identified as optimal, whereas the sample with a corrosion rate of 23.99 mpy demonstrated inferior performance. The formation of a passive Cr?O? oxide layer by chromium, the stabilizing effect of nickel, and the presence of copper oxides (Cu?O) in the synthesized coating contributed to the mitigation of pitting and galvanic corrosion. Moreover, the homogeneous elemental distribution within the HEA structure reduced susceptibility to intergranular corrosion. The antibacterial properties of the synthesized coating were also investigated. The results demonstrated that leveraging the synergistic effects of the high-entropy alloy enabled exceptional antibacterial efficacy against planktonic bacteria and biofilms, achieved through the integration of antibacterial elements into the final CoCrNiCuZn coating. This study enhanced the antibacterial performance of HEAs through advanced fabrication techniques and assessed their feasibility as biomedical and corrosion-resistant materials with antibacterial functionality. Overall, this research presents a one-step, scalable, and cost-effective approach for synthesizing nanocrystalline HEA coatings, offering substantial potential for industrial and academic applications in materials science and metallurgy.

   This research investigates the transient liquid phase bonding process assisted by electric current for joining thin sections. The simulation of this process was conducted using COMSOL software in two systems: copper-carbon steel-copper and copper-tin-copper, with varying layer thicknesses. The primary objective was to analyze temperature distribution and atomic diffusion during the bonding process. The results showed that in the copper-carbon steel-copper system, the temperature at the center of the piece reached approximately 1590°C, sufficient to melt the interlayer. It was also observed that increasing the base layer thickness from 1 mm to 5 mm resulted in a higher final bonding temperature. Atomic diffusion analysis revealed that the maximum diffusion depth occurred with a base layer thickness of 1 mm and an interlayer thickness of 0.02 mm, reaching a depth of 0.252 mm. In the copper-tin-copper system, the center temperature of the sample reached approximately 766°C, adequate for melting the tin layer. Modeling indicated that in both systems, the sample remained at the final bonding temperature for over 95% of the bonding time, highlighting a unique advantage of this method. The results were validated by comparing them with experimental data available in the literature, showing good agreement. This research's findings can contribute to the optimal design of transient liquid phase resistance bonding processes for industrial applications, particularly in microelectronics.

   Dental implants are subject to complex mechanical and biological conditions. On the one hand, it is under cyclic pressure and corrosive environment, and on the other hand, chemical reactions occur on the surface of the implant with the biological environment. Therefore, not only surface conditions and topography, but also strength, fatigue resistance and biocompatibility will be important in the implant placement process. Currently, some grades of titanium such as grade 2, 4 and 5, as well as some alloys such as Ti-6Al-4V alloy and Ti-Ni duplex alloy are used by different manufacturers to make dental implants. Considerable information on the properties of these materials can be found in scientific sources, however, it is difficult to compare these materials in order to select appropriate materials for biological applications. Because the different working conditions for using these materials, as well as the history of the operations performed on these materials, make it difficult to compare them. In this research, the surface properties, corrosion, and biocompatibility of some titanium alloys will be studied after acid washing and surface modification under the same conditions.   Keywords: implant - fatigue - titanium zirconium alloy.

In recent decades, we have seen a rapid increase in population growth. For this reason, the high combination of social and economic activities in large urban areas has led to the emergence of different services and tra  ortation methods. Urban traffic congestion has become a challenge for cities around the world. Excessive delays, slow travel speeds, increased travel costs, increased driver anxiety and frustration, high fuel consumption, and air pollution are just a few of the consequences of traffic congestion. Traffic demand fluctuates significantly throughout the day, especially during peak traffic hours, which is one of the main causes of traffic congestion. The reduction of travel time when considered overall and at the network level shows very important results. One of the main ones is economic issues. Reducing travel time is a win-win equation for the user and the provider. The users are the passengers and users of the tra  ortation network of the cities, and this will reduce their costs for tra  ortation. On the other hand, when the travel time of the entire network is reduced and the number of traffic jams per day is reduced, the need to spend large amounts of money on improving road infrastructure and tra  ortation services will be reduced, which is economical. The savings will be enormous. This research was done with the aim of determining the impact of using the routing program on reducing the travel time of the entire network. For this purpose, Aimsun software was used and a part of Kermanshah city was modeled in this software. The percentage of 0, 25, 50, 75 and 100 of the users who use the router program is defined and at the end the results for these five modes are compared. It has decreased by 25%.   

Currently, heavy machinery is used in the world to tra  ort and construct roads. To speed up the implementation of road construction, fabric concrete was investigated. One of the ways to speed up the implementation of asphalt is to use fabric concrete, which is easier to carry, higher transfer speed, and does not require a lot of time to gain strength, making fabric concrete more attractive than other methods and materials. In this research, using the software analysis method, it has been tried to investigate the effect of using fabric concrete on asphalt tensile strength and pavement strains. This research is expected to reduce the thickness of the asphalt layers, the base and sub-base and the use of fabric concrete, the cost and time of the projects will be reduced and it will also increase the tensile strength of the asphalt. On the other hand, this change will increase the pavement life and reduce Damages and settlement of the asphalt layer. Research methodology: In the current research, the analysis method is finite elements using ABAQUS software. Now we intend to reduce the thickness of the asphalt layer, base and sub-base by using fabric concrete reinforced with aramid fibers and adding it with asphalt. And increase the tensile strength of the asphalt pavement, which our modeling has been done using the available past articles and researches. In this research, we have made 8 pavement models, one without fabric concrete and four other models It is with fabric concrete with different thicknesses and three end models by reducing the thickness of the asphalt and removing one of the base and sub-base layers, and we compare the results and analyzes obtained from the Abaqus software with each other. Conclusion: According to the obtained results: with the addition of fabric concrete, the tensile strength of asphalt is increased and the thickness of the base and sub-base layers can be reduced, and the strains created in these layers experience a significant reduction. Reducing the strain and increasing the tensile strength of the layers has reduced the damage caused to the surface of the pavement and controls the settlement of the asphalt layer and has created roads with higher safety and less risk of accidents.   

Developing the scope of application of new material depends on understanding the behavior of these in different environments and also gaining knowledge on the effect of various factors such as heat treatment parameters on their properties.   With regard to this issue we focused on the investigation the effect of partial austenitizing duration on creating a matrix with a dual structure of ferrite-ausferrite, corrosion resistance, bending strength, time to failure in crosive media under applied bending loads and stress corrosion threshold stress of a carbidic austempered ductile iron (CADI) which has been known as new family of ADI. In this regard, cast parts from a non-alloy carbidc cast iron were first subjected to ferritizing annealing to obtain full ferritic matrix. Then, the samples were partially austenitized at 870 ?C for 10, 15, and 20 minutes, followed by austempering in a molten salt bath at 350 ?C for one hour. After it, samples microstructures were examined with an optical microscope. In the next step, electrochemical corrosion tests were performed with Tafel polarization method. Then, by preparing notched and smooth C-ring samples, the loads leading to their failure were determined under the bending tests in air. Finally, the behavior of C-ring samples in corrosive caustic soda solution were investigated under bending loads. According to the obtained results, with the increase of the partial austenitizing time, the ausferrite phase fraction increased according to the JMAK equation. The creation of dual matrix structure of ferrite-ausferrite caused the corrosion resistance of the samples to be weakened compared to the samples with fully ferritic matrix and conventional ADI. As the partial austenitizing time increased, the corrosion resistance, bending tensile strength in air and time to failure in corrosive media under constant load, increased. The bending loads leading to the failure of notched samples in air were significantly lower than those of smooth samples. The results of stress analysis in C-ring samples under bending test in air showed that the reduction of cross-sectional area, change the outer effective radius and neutral radius of the samples, and stress concentration are three contributing factors in reducing the tolerable bending load without occouranse failure with the contribution of 35%, 35% and 30%, respectively. The notch strength ratio (NSR) was independent of the effect of partial austenitizing time and it was about 0.87. All the smooth samples endured 100 hours of stress-corrosion testing under maximum applied loads (equivalent to 85% of failure load in air) without occurrence of failure. By decreasing the applied load in the corrosive environment, the time to failure of all samples increased greatly. There was a power relationship between the stress-corrosion threshold stress and the ultimate tensile strength of the samples. Also, during stress-corrosion testing the gradual fracture along with growth of cracks was not observed and failure of all samples in both environments air and caustic soda occurred via very rapid crack propagation in a completely brittle mode over the whole range of the applied loads.   

   Due to the presence of impurities in liquid toluene as a feed for industrial units, these units witness a significant drop in the quality of their products. The mono- and multi-component adsorption of organic impurities from toluene, as an organic phase, was carried out using granular activated carbon (GAC). Ethylcyclopentane (ECP), Methylbenzothiophene (MBT) and Xylene (XYL) were considered as the main components of synthetic solution representative the non-aromatic, sulfur, and aromatic impurity groups in real feed-stock, respectively. Continuous experiments on a packed column under the different bed height (60-120 cm), liquid flow rate (1-3 L/min) and adsorbate initial concentration (200-400 mg/L) were evaluated on breakthrough curves. Breakthrough curves are considered as basic tools in the design and construction of surface adsorption system on an industrial scale. Also, the performance and efficiency of adsorption to remove pollutants and impurities from the flow in a fixed-bed column is usually evaluated by Breakthrough curves. The GAC successfully adsorbates ECP, MBT and XYL from toluene. Among the various breakthrough models available in literature, the Thomas model had a well correlation (R2 >0.93) with all three adsorbates. As well as, the results showed that increasing the depth of the adsorbent improved the removal of ECP, MBT and XYL, while increasing the flow rate and the concentration of adsorbates reduced the removal of ECP, MBT and XYL. Experimental results in mono- and multi-component systems reveal the order of these compounds in term of adsorption affinity onto GAC as MBT > ECP > XYL. Besides, a computational fluid dynamic (CFD) simulation model was developed to simulate and analyze the adsorbates concentration inside of the adsorption column. The simulated breakthrough curve had a good reproducibility with experimental data (R2 >0.97). In addition, the CFD model shows a high mass transfer zone and a slow adsorption rate in all tests of adsorbates adsorption; as well as, the mass transfer zone grew as the bed height increased.

با توجه به نياز روز افزون منابع انرژي، سطح مصرف انرژي در جهان افزايش يافته است. از اين رو دسترسي كشورهاي درحال توسعه به انواع منابع جديد انرژي بويژه انرژي هاي پاك اهميت اساسي دارد و با توجه به كم شدن ذخاير محدود انرژي فسيلي و همچنين دلايل زيست محيطي ديگر نمي توان به آن متكي بود. از اين رو استفاده از انرژي هاي پاك مانند انرژي باد مي تواند جايگاه ويژه اي داشته باشد. در اين بررسي عملكرد انواع توربين هاي بادي، بويژه توربين هاي بدون پره و آشنايي با پديده جريان هاي گردابي كه اساس توربين هاي بدون پره را تشكيل مي دهد ارائه شده است. از اين رو در اين راستا طراحي، مدلسازي و شبيه سازي اين نوع توربين هاي بدون پره انجام شد .ابتدا شبيه سازي دو بعدي سيستم هاي گردابي در حالت استوانه ساكن در رينولدز هاي 60 و 40 انجام شد. در ادامه چهار نوع هندسه ي مختلف دايره، نيم دايره، قيف و نيم دايره-مربع طراحي و شبيه سازي دو بعدي گردابي نوساني VIV آن، در اين چهار هندسه ها در رينولدز 51600 انجام و مقادير جابجايي در جهت عرضي، نيرو هاي درگ و ليفت و ضرايب آنها و همچنين الگوي جريان گردابي پشت اين اجسام بررسي شد. مشخص شد كه هندسه ي نيم دايره-مربع بيشترين مقدار فركانس رابا مقدار 5.747 هرتز نسبت به ساير هندسه ها دارد.   در ادامه مهمترين پارامتر تاثير گذار عدد بدون بعد رينولدز بر عملكرد اين نوع هندسه در سه محدوده ي 30000 ، 51600 و 100000 بررسي و مشخص شد هندسه ي مورد نظر در محدوده ي رينولدز 100000 بيشترين تعداد نوسان جابجايي و سرعت و ضريب ليفت را دارد.

Implant Insertion is not always successful, Because of inappropriate stability of implant-bone intersection. It seems implant geometrical including length, diameter, Number and depths flutes are affected on stresses and mechanical stability. The purpose of this research is study of implant geometrical variable such as numbers, angle and length of vertical grooves (Flute) on stress distribution and the amount of the implant displacement during static and periodic loads using finite elements Method (FEM) according to ISO 14801 international Standard. founded, that the effect of geometrical variables such as the length of the groove on the implant stem, the angles and Flute’s Number on the overall life of the dental implant and the amount of displacement after implantation has been very effective, so that the diagonalization of the groove has increased the tension better and its length is also more optimal in the original implant. Convergence of geometric variables such as alpha 6 degrees, beta 12 degrees, three grooves, with a fixed groove length will increase the life and stability of the implant by reducing the displacement of the implant in the anchor(bone). Since creating the final torque on the abutment causes the mechanical stability of the dental implant, the torque and loading couple will also stabilize the implant in the bone and increase its lifelog. When the abutment in the implant is tightened with a torque of 35 newton.mm. It causes more stability through more engagement with the surrounding bone.

  self-healing is related to the repair of cracks due to loading and it can be considered as a reversible fatigue phenomenon. Asphalt mix is ??a self-healing material and has the ability to automatically repair damage when exposed to rest periods. This phenomenon depends on various factors such as temperature, rest time, crack width and bitumen and asphalt properties. The rate of repair at ambient temperature, especially at low temperatures, is slow and the flow of traffic on the road can not be blocked to achieve sufficient repair. On the other hand, self-healing of asphalt concrete is significantly dependent on temperature and when the pavement is exposed to higher temperatures, the amount of repair also increases. Self-healing has been studied in two areas of rejuvenation and rapid heating Is. To investigate the effects of temperature on self-healing, we are looking for the best and most economical means and method for generating heat in the asphalt mixture. Among the heating methods, we can mention heating by electromagnetic waves and microwave. Microwaves raise the internal temperature of the asphalt in a short time, which helps in self-healing. There are several methods for evaluating the quality and quantity of self-healing, such as fatigue-based tests, rupture-based tests, and non-destructive tests. In this study, the behavior of graphite nitride carbon additives and polyaniline nanofibers on nanosilica-modified hot asphalt self-healing was investigated by three-point bending test. First, the flexural strength of the samples was obtained by a three-point bending device, then the samples were repaired by heating by a microwave device for 24 hours, then the degree of improvement was determined. In evaluating the self-healing process in the hot asphalt mixture modified with nanosilica, the analysis of the results showed that by adding nanosilica, the negative effect of zeolite on the self-healing asphalt used to produce hot asphalt is compensated and the self-healing rate of asphalt increases. On the other hand, two additives of graphite nitride carbon and polyanylene nanofibers have a positive effect on self-healing and even improve the self-healing of asphalt mixture up to 80%.

  Color is one of the most important quality properties of the product that is first visible to the consumer. Color is an effective factor in attracting attention and selecting the food that is received through the sense of sight, and its presence in the rapid diagnosis and final acceptance of each product will be due to its attractiveness. According to the FDA (Food and Drug Administration) definition, food coloring is: "A color additive contains any dye, pigment, or other substance made by a synthetic process or similar method, or from a plant, animal, "Minerals and other sources or intermediates have been extracted, isolated and derived, and when used for food, medicine, cosmetics or any other part, can create and add color to it." Which will be added to food, beverages and cosmetics for human consumption in order to create color. According to this definition, colors are divided into two categories: licensed for consumption (ie, for food consumption, a license is required, such as dyes of natural origin) and non-licensed for consumption (ie, it is not necessary to obtain a license for consumption). Fabrics and carpets are used) are divided. With the passage of time and the increasing need of various cosmetic, health, textile, food, etc. industries for more and more diverse colors, humans began to prepare and mass-produce dyes in an industrial way, the production and consumption of which in non-food industries caused Air pollution, groundwater aquifers, running water, pollution of agricultural lands and pastures in the food, cosmetics and health industries have caused deep concern about the safety of chemical or synthetic dyes in the health of the body (1). Due to the allergic effects of some artificial colors in foods such as azerobin or tartrazine, their use in various food industries is limited (8). Some synthetic dyes also show carcinogenic and mutagenic effects, for example dye used in the meat industry to form nitrosamines. This substance combines with nitrate and nitrite to form an amino agent (9) in order to To counteract these harmful effects, there is a global trend towards the production of pigments from natural sources. Natural dyes are derived from two important sources of plants and microorganisms. In the meantime, dyes derived from fungal sources have wide and very important applications in the nutrition and economy of human society and are able to create a profit of about $ 30 billion per year in the industrial process. The number of different colors in fungi is more than a thousand species that are not found in other organisms or are very small (1). Permissible edible and natural pigments of plant origin will cause many problems such as instability against light, heat, low or high acidity, low solubility and often lack of easy access throughout the year (2).

  According toforecasts, the world will face an energy crisis and issues related togreenhouse effects and environmental pollution in the near future. Therefore,the use of environmentally friendly vehicles, such as electric vehicles, aswell as the trend towards renewable energy in the future, will be inevitable.According to statistics, 83% of electric vehicles use permanent magnetsynchronous motors. Also in wind turbine applications, the approach of largecompanies in the world such as Siemens and General Electric, is to use largegenerators with high power density and reliability. The share of permanentmagnet synchronous machines (PMSM) is higher than other electric machines. Thereason is the significant improvement in the properties of permanent magnetsand significant reduction in their price in recent years. Due to the popularityof PMSM in the new energy industry, research has started on the design andconstruction of well-functioning drives for these machines. In thisdissertation, the torque control of this machine has been done using the modelpredictive control (MPC) method. The aim of this dissertation is to provide amethod for simultaneously reducing torque ripple and switching frequency with asmaller computational burden than the previous methods. By reducing the torqueripple, the performance of the drive and motor is improved and by reducing thecomputational burden, it is possible to implement this method on a variety ofmicrocontrollers.Keywords: Model PredictionTorque Control, Discrete Space Vector Modulation, Switching Frequency,Permanent Magnet Synchronous Motor

   Abstract:    Ti-6Al-4V alloy with good tribological properties, low elastic modulus, high strength to weight ratio and Co-Cr-Mo alloy with excellent corrosion and abrasion resistance are used as metal biomaterials in artificial joints. In this study, the biocompatibility of the bimetallic system of Co-Cr-Mo and Ti-6Al-4V alloys, which are connected to each other through the transient liquid phase (TLP) process was evaluated. In this study, samples without coating and with hydroxyapatite coating were evaluated. The Phase composition, coating microstructure, corrosion resistance, metal ion release rate and cytotoxicity of samples were examined by using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Polarization, Inductively Coupled Plasma (ICP) and MTT tests. The results showed the presence of uniform and nanometer coating on the coated samples. Examination of corrosion resistance in SBF solution and blood serum showed that CT1 sample without coating had optimal resistance (icorr = 1.01 ?Acm?2 in serum solution and icorr = 1.25 ?Acm?2 in body simulation solution) and also the resistance of coated samples It is much more desirable than uncoated samples and the best result was related to HAp-CT1 sample (icorr = 0.1 ?Acm?2 in serum solution and icorr = 0.08 ?Acm?2 in body simulation solution). The results of ICP test showed that the release rate of ions in 7, 14, 28 days was less than the allowable limit. By performing cytotoxicity test, it was observed that the death rate of cultured cells on the samples within 3 days was a desirable value and close to the control sample and had a significant difference of p <0.05. In addition, cell growth on CT1 sample increased during 3 days, which indicates the optimal biocompatibility of CT1 sample compared to other samples. The results of tests performed in this study showed that the samples have good biocompatibility and the best result is related to CT1 sample. It was also observed that the hydroxyapatite coating applied on the samples significantly increased the biocompatibility rate. Key Words: TLP bonding, Biocompatibility, Corrosion Resistance, Metal Ion Release, Cytotoxicity.

  Abstract Images are the most important and widely used digital data used in computer systems. A digital image is made up of a set of objects or areas, so one of the efficient techniques for extracting features from images with respect to their constituent objects is the image segmentation technique, which delimits objects or areas. Highlights the image with high accuracy due to its texture and features. Using image segmentation, image pixels are placed next to each other in specific areas due to common features and generally similarity to each other. Multi-level image thresholding is one of the most popular and at the same time the simplest and most efficient methods of image segmentation. The most important issue in this method is the selection of the value of the relevant thresholds. In such a way that by determining the appropriate thresholds, the desired image can be more accurately zoned. Atsu method is one of the thresholding methods that has a good performance in determining two-level thresholds, but when increasing the number of thresholds, Atsu performance decreases in terms of time and segmentation accuracy. Therefore, it is combined with optimization algorithms to achieve better performance in terms of time and segmentation accuracy. In this research, an improved Grasshopper optimization algorithm is also proposed to increase the accuracy of finding answers and increasing the accuracy of segmentation, as well as to increase image quality. In this method, Atsu evaluation function is proposed for the image segmentation process in optimization algorithms. According to experiments and results, the improved Grasshopper algorithm is performs better compared to the optimization algorithms for Grasshopper, whale, firefly and bee colony. Keywords: Image segmentation, Improved Grasshopper Optimization Algorithm, Grasshopper Optimization Algorithm, Firefly optimization algorithm, Artificial Bee colony algorithm and Whale optimization algorithm. Abstract Images are the most important and widely used digital data used in computer systems. A digital image is made up of a set of objects or areas, so one of the efficient techniques for extracting features from images with respect to their constituent objects is the image segmentation technique, which delimits objects or areas. Highlights the image with high accuracy due to its texture and features. Using image segmentation, image pixels are placed next to each other in specific areas due to common features and generally similarity to each other. Multi-level image thresholding is one of the most popular and at the same time the simplest and most efficient methods of image segmentation. The most important issue in this method is the selection of the value of the relevant thresholds. In such a way that by determining the appropriate thresholds, the desired image can be more accurately zoned. Atsu method is one of the thresholding methods that has a good performance in determining two-level thresholds, but when increasing the number of thresholds, Atsu performance decreases in terms of time and segmentation accuracy. Therefore, it is combined with optimization algorithms to achieve better performance in terms of time and segmentation accuracy. In this research, an improved Grasshopper optimization algorithm is also proposed to increase the accuracy of finding answers and increasing the accuracy of segmentation, as well as to increase image quality. In this method, Atsu evaluation function is proposed for the image segmentation process in optimization algorithms. According to experiments and results, the improved Grasshopper algorithm is performs better compared to the optimization algorithms for Grasshopper, whale, firefly and bee colony. Keywords:

One of the most important issues in welded parts is the existence of residual stress due to the heat distribution. In this research the effect of residual stress on the energy absorption of steel tubes due to spiral welding, using various parameters such as the number of spirals and welding current intensity, in the manner of experimental/simulation has been studied. The compressive test has been used in order to determine the amount of energy absorption in the welded tubes. Also in the numerical simulation, the spiral welding process, heat distribution, residual stress distribution, tube folding and the force-displacement diagrams has been investigated. At the end, the results of experimental tests and numerical simulation has been compared and analyzed.   

Solution to increase and decrease the radiation of radio signals in buildings

Abstract    In this study, in order to investigate the effect of iron additive on the heat transfer coefficient as well as the dynamic properties of unsaturated polyester resin, pure iron particles in powder form with a size of 45 microns have been used. For this purpose, in the continuation of the research, samples of unsaturated polyester resin containing iron particles with weight percentages of one, three, seven and fifteen weight percent were made and thermal conductivity measurement tests and dynamic properties measurement test (DMTA) were made. Also, to investigate the effect of modified iron particles on the properties of the composite, four samples of unsaturated polyester resin with similar weight percentages containing modified iron particles were tested.    Examination of the results of measuring the thermal conductivity of the samples, it was observed that in general, the addition of iron powder to the polyester resin improved by about 30 Percentage the thermal conductivity of the samples and also the addition of modified iron powder to the polyester resin by about 70 Percentage, its thermal conductivity has increased. Also, by observing the change curve of the thermal conductivity of the samples in different weight percentages, it was found that adding iron particles from one to three weight percent increased the thermal conductivity of the resin and adding more values ??up to fifteen wt %, the thermal conductivity. It has reduced. The reason for this could be the increase in the contact surface of iron particles with the resin and, of course, the increase in interfacial thermal resistance in samples above 3 % by weight. It should be noted that this trend is also repeated in the diagrams of samples containing modified iron particles.    Examination of the dynamic measurement test results showed that the amount of storage modulus increased with the addition of iron particles to the polyester resin and indicates that the unsaturated polyester resin containing iron particles has a higher strength during heating than pure polyester resin. Observation of the change curves of the storage modulus with temperature shows that this increase of the storage modulus did not have a constant trend with increasing the weight percentage of the samples, so that, for example, the storage modulus in the sample was 7 % by weight higher than other samples.    Keywords: Unsaturated polyester resin, Iron microparticles, Modified Iron Particle, Thermal conductivity, Physical and Mechanical Properties.   

  In recent years, due to the expansion of cities, today urban tra  ortation has become important and at the same time has many special complexities and cities are facing increasing population density and activities. This increase has various adverse effects and consequences, including air pollution, noise pollution and environmental pollution. Kermanshah, the ninth most populous city in Iran and the second most populous city in the west of the country, is after Tabriz. One million people will pass. Given the volume of intercity travel in the city of Kermanshah, the need to provide and review efficient forecasting methods for tra  ortation and the number of intercity trips and other influential parameters for the future has become increasingly apparent. In a way, this improves the conditions, including employment and economic and social investments, and increases the quality of life. The purpose of this research is descriptive, mathematical and innovative analysis using artificial intelligence, mlp neural network. The purpose of this study is to present a model using artificial intelligence to study and distribute population and urban employment and its relationship with the number of intra-city trips in different areas in Kermanshah. In such a way that according to these changes, necessary and appropriate management actions and planning are done. In this study, the independent variables are demographic information, employees, vehicles and number of students, while the dependent variables are tra  ortation and number of trips produced. Each of these parameters was examined in Kermanshah and then compared to the conventional model of exponential growth rate. Been paid. Finally, mlp neural network has been used to analyze the data using significant variables. The results show the appropriate efficiency of the neural network in analyzing and predicting the number of future city trips compared to other conventional methods.

Spent caustic is one of the polluted effluents of oil refineries and petrochemical companies, that has a very unpleasant and pungent odor and high amount of COD due to the high content of pollutants such as sulfides, mercaptanes, naphthenic and cresylic acids. because of the type of chemicals, contained in the spent caustic, it can be environmentally hazardous and difficult to treat conventional treatment. In current experimental study, wet air oxidation as an efficient method in this field, is used to treat merox unit spent caustic. the experiments were performed under different condition of temperature, pressure and gas/liquid ratio. The effect of temperature on COD reduction was investigated for first feed. The results showed in three different temperature 130, 145, 160 C the COD reduction is equal to 32%, 36.8% and 46.3% respectively.

  First, by reviewing the scientific literature, suitable conditions for the electrodeposition of nickel-tungsten nano-coatings are determined, and after preparing a suitable coating, nitriding operations are performed on the samples. Further erosive corrosion of pure steel, nickel and tungsten nickel coating were investigated .The electron microscope and X-ray diffraction studies are performed at each step.   

سوپرآلياژها،آلياژهايي پركاربرد در صنايع استراتژيك هستند كه سختي و مقاومت بالا،ماشينكاري آنها را با مشكلاتي همراه كرده است.ارايه شيوه اي تركيبي براي پرداخت نهايي سطح سوپرآلياژها و رسيدن به صافي سطح مناسبتر، هدفي است كه به آن پرداخته شده است.

  In this research, the AISI304 steel was bonded successfully with MBF-15 and MBF-80 interlayers by Transient Liquid Phase [1]method. Then friction stir process[2] was performed on the bond region and the effect of the process on microstructure and mechanical properties was investigated. The base metal and each of interlayers separately was assembled and the bonding operation was done in 11350c temperature for 20 min in a semi-vacuum environment furnace. Afterward Friction Stir process applied with using a designed tool made from tungsten carbide material. The process was accomplished with a milling machine. Rotating speed of tool was 600 Rpm/min and traverse speed was 10 mm/s. the process was applied at two side of the bond line. Processed and not processed samples were prepared and investigate with optical and scanning electron microscope. The microstructure of samples compared with each other. To analyze the composition and phase recognition energy dispersive spectrometry[3] and XRD was used. To evaluate the mechanical properties and the effect of FSP on it shear strength test and micro hardness performed. The microstructure evaluation showed that before FSP for each of interlayers, there were some eutectic phase in center of bond and residual phase in the diffusion zone of TLP. Before FSP, for MBF-15 interlayer, the central phase is Ni-Si, Fe-B, Ni-B and CrB4 in DAZ of TLP. The eutectic phases in the central zone of bond by MBF-80 interlayer are Fe-B-Ni-B and brittle Cr5B3 in DAZ. These eutectic and residual phases reduce the mechanical strength of the joint.FSP was applied as a technique to modify the distribution of alloying elements and intermetallic phases. Underneath of FSP route, 3 zones were formed: 1. Nugget zone that distribution of intermetallic is perfect. 2.Thermo Mechanically Affected Zone[4]. and. 3. Heat Affected Zone [5]that the quantity of intermetallic phases is reduced because of dissolution of eutectic and residual phase. The shear strength and hardness of the nugget zone after FSP will be better than before FSP for both interlayers. This improvement for joint with MBF-15 interlayer is better than MBF-80.   And shear strength of joint with MBF-15 interlayer is close to base metal shear strength after the process.1-TLP2-FSP3-EDS

  this present literature investigates the thermal buckling and vibration of functionally graded porous nanocomposite beam reinforced by graphene platelets based on Timoshenko beam theory . This study focuses on the effect of the porosity distribution , porosity   coefficient and the effect of the variou   GPLs dispersion pattern , size and geometry of GPLs ,as well as the influence of   eam boundary conditions ,slenderness ratio and the thermal gradient   . Because of the negative thermal expansion coefficent of graphene , the critical thermal buckling gradient is in a high range. the numerical results suggest that introducing the little amount of GPLs enhances remarkably the stiffness of the present structure ,on the   other hand ,due to negative thermal expansion coefficient of nano fillers ,the studied beam acceptably behaves in high thermal gradient .Both porosity distribution and GPLs pattern obviously affect on frequency increment   although the effect of GPLs pattern is more .In a certain ,when the porosity coefficient increases ,the frequency increment decreases , though this decrease is much less . the effect of   oundary conditions on frequency increment is not so much. According to the results ,the relation between slenderness ratio and frequency is inverse.  Analyzing the effect of   increase on beam frequency suggests that increasing thermal gradient , the beam frequency lessens. Meantime The effect of   increase on frequency increment is different in beams with various porosity distributions and GPLs pattern.

  In this research, utilizing transient liquid phase (TLP) joining for bio as-cast Co-28Cr-6Mo alloy similar bonding was investigated. Due to the good abrasion resistance, high mechanical properties, adequate corrosion resistance, high biocompatibility, as well as lower prices than gold base alloys, these alloys are the most suitable for biomedical applications. To this end, the TLP connection was performed using a MBF-100 cobalt-based and MBM-60 nickel-based interfacial layer with a thickness of 25 microns under argon gas atmosphere conditions at 1175 ?C and 15 min, and 1160?C and 60 min, 1170?C and 30 minutes , 1170 ?C and 60 min, and 1170 ?C and 120 min. The MBF-60 nickel base MBF-60 interface was also subjected to ambient atmospheres and vacuum of   torr at 950, 1000, 1050, 1100, 1170 and 1240 ?C.In order to test the mechanical properties of bonding, the bonded specimens were subjected to cutting tests. The results showed that the bond strength of MBF-100 interlayer at 1170 ° C and 2 h had the highest shear strength. The strength of sample bonding was reached 81% of base metal. Also, the effect of complete thermal solvent treatment at 1240 ° C and 4 h on shear bond strength was investigated. It was observed that at the same temperature and time, the complete solution sample had a higher strength than the bonding of as-cast samples in similar conditions. The highest bond strength was   for MBF-60 at 1000 ° C and 2 h.Investigation of microstructural analysis of the bonding was done using optical microscope and scanning electron microscopy (SEM) and SEM-EDS analysis results. The results of the bonding samples of 1175?C and 15 min using MBF-100 interlayer indicated that the melting was done on the boundaries at a bonding. By increasing the bonding time to 2 h at 1170?C, the penetration rate expanded, resulting in uniformity of the bonding region compounds and reduction of the phases present in the bonding region, indicating the expansion of the isothermal solidification zone. Boride compounds were also found in this sample indicate their stability.In joining studies conducted with the MBF-60 interlayer, it was found that in the bonding sample at 1000 ° C and 2 h, according to the EDS analysis the compounds were isolated as Cr3P3, Crp, Cr12P7, and CoP, and the phases Spherical is also seen in the DAZ zone. At temperatures, 1170° C was also observed continuous eutectic compounds at the center of the joint. The standard homogenization carbides dissolution process was carried out at 1240 ° C for 4 h the temperature for 4 hours. According to the microstructure bonding, the undesired phases of the bonding zone were significantly reduced and the homogeneity was observed. At this temperature, the carbides were completely dissolved and the granularity formed in the bonding zone.  

  The Ti-6Al-4V alloy with good tribiological characteristics, low elastic modulus, high strength to weight ratio and the Co-Cr-Mo with excellent resistance to corrosion and erosion, are practical as metal bio-materials in artificial joints. The Co-Cr-Mo alloy leads to reduced corrosion in the thigh joint and the Ti-6Al-4V alloy easily pairs up with surrounding bones and is therefore preferred for thigh stem. To build such a bimetal system, given the disparity of welding parameters, connection is a big hurdle. Different welding methods such as fusion welding, laser welding, hard and soft soldering, and penetration bonding for simillar and disimillar bonding of these alloys have been used. In this study, the transient liquid phase   rocess has been used for the Ti-6Al-4V/Co-Cr-Mo dissimilar system in order to address the shortcomings of other welding methods and access mechanical properties comparable with base metal. In this method, samples were cut as cylinders with 8 mm in diameter and 5.7 mm in height and their surfaces were prepared for bonding. An copper interlayer was placed between the two surfaces as covering on cobalt sample, and a constant pressure of 1 MPa was applied to the samples using fixture. Next, the bonding set was exposed to heating in under-pressure stove with the different temperatures of 925, 950 and 975, considering the eutectic temperature of Ti-Cu (about 875 °C), for 5 to 120 minutes. On the connected samples, cross section cut was performed and the substructure was studied using optical microscope. Results suggested that as a result of the bonding, 3 zones of DAZ (diffusion-affected region), ASZ (athermally solidified zone), and ISZ (isothermally solidified zone) appear in the bonding point, with the length of these zones differing depending on conditions of performing the bonding, and as joint temperature and duration increases, the athermally solidified zone can be removed, thus leading to progressed isothermally solidification during the bonding. Cut test was used to investigate mechanical strength of the samples, with the maximum shear strength equal to 350 MPa, which is around 50% of the base metal, obtained for the bonding made at 950 °C and in duration of 2 hours. Also, the failure level of the samples was identified with the X-ray diffraction test and failure level combination was considered. Type of failure and elements present in different phases of sample cross-sections were investigated using scanning electron microscopy. Elements constituting present elements were identified via the EDS test, and element changes in the sample were obtained with linear analysis. Keywords: transient liquid phase (TLP), Ti-6Al-4V, Co-Cr-Mo, evaluation of microstructure, mechanical properties, copper interlayer  

Abstract:  The pipelines that are used in the petroleum industry tra  ort gas and oil with content of sulfidric gas that intensifies the adsorption of hydrogen in the metallic surface provoking the absorption of hydrogen in the wall of the pipe, what can flow in a embrittlement processThe welding process and the manufacturing process can also facilitate entry of hydrogen into the steel.The work done by other researchers suggest several parameters in the hydrogen losses had an impact. For example, have shown that the microstructures ferritic microstructure of ferrite needle more resistant to damage by hydrogen. Also tempered martensite microstructure bainite structures to very fine particles, perlite and martensite shows better behavior. Impurities and inclusions as trapping hydrogen in steels resources to act. Manganese sulfide is known as a harmful impurities.In this project, API 5L X60 pipes used in oil refineries Ntg Bijar area Kermanshah related to oil and gas companies have been defeated West under analysis. It was found that impurities MnS significant role in the formation of cracks were HIC. So that all EDS analysis show the presence of these impurities left in the region. Studies also show that the microstructure of the steel microstructure ferrite - pearlite with a hardness of 210 Vickers is that in some parts of needle ferrite and ferrite Weidman Ashtatn was observed in some areas.