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.

   Abstract Two-phase matrix carbide ductile irons are a new idea i  ired by the processes of producing two-phase matrix ductile irons and producing austempered carbide ductile irons containing free carbide. As an emerging align="left" dir="LTR" >Keywords: Intercritical austenite, carbide ductile iron, austemper temperature, corrosion behavior, two-phase contex.

In this thesis, a novel artificial intelligence-based method is proposed for fast and accurate fault detection in three-phase three-level inverters. This approach analyzes current and voltage signals, extracts key features, and employs machine learning algorithms such as Random Forest and SVM to learn the system’s behavior under both normal and faulty conditions, enabling effective fault identification. To evaluate performance, simulations were carried out in the MATLAB/Simulink environment, and the resulting data were used for training and testing the model. The results indicate that the SVM model outperforms the other models used in this study in terms of speed. It is noteworthy that, in addition to achieving high accuracy, the proposed method also demonstrates good generalization capability, which enhances system reliability and reduces maintenance costs in power systems. Furthermore, the method can be further improved in the future through the integration of deep learning and reinforcement learning algorithms.   

   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.

   Insert text here. Fatigue cracking is one of the main problems of asphalt pavements that affects the durability of the pavement. Self-healing ability is one of the factors that can lead to asphalt resistance against fatigue cracks caused by traffic loading and ultimately increase the fatigue life of asphalt pavement. Every year, a large part of road maintenance and repair costs are spent on fixing the damages caused by these cracks. Therefore, researchers are looking for ways to recognize and increase the use of self-healing capabilities to increase pavement life and reduce road maintenance costs. This research examines the effects of styrene-butadiene-styrene (  ) and carbon fibers (CF) on asphalt self-healing ability through the three-point bending test, and the effect of    and carbon fiber on the microwave heating process. Also, in this research, the temperature of the surface and inside of the asphalt samples has been investigated.   In line with this research, four types of asphalt samples were made, including asphalt without additives, asphalt with    additives, asphalt with CF additives, and asphalt with both    and CF additives. In this research, in order to evaluate and compare the self-healing in different asphalt samples, the ratio of secondary resistance to primary resistance is defined as healing index (HI). The results showed that carbon fibers cause a more uniform distribution of temperature and increase the heating speed of asphalt, but it has reduced the primary and secondary resistance of asphalt to a great extent compared to asphalt without additives.    improved the strength performance of asphalt samples to a great extent, so that the average initial flexural strength of samples made with    is about 180% of the average initial flexural strength of samples made without additives. Also,    decreased the average temperature of the surface and inside of the asphalt samples and made the temperature distribution weaker. These two additives did not increase the asphalt healing index compared to the asphalt without additives.   

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  In this research, the effects of sandblasting variables, including mesh size, pressure, distance and time of particle spraying, on the hydrophilicity and roughness of titanium samples were investigated. For this purpose, the desired surface properties were obtained by cleaning the samples through two-step acid washing. After each step, the samples were tested in terms of roughness and hydrophilicity. Also, the surface morphology of the samples was analyzed by scanning electron microscopy (FESEM) in order to determine the best acid washing time. Various biological tests including cell culture, cell toxicity, antibacterial, and protein adsorption were also performed on the samples. SEM images obtained from the sandblasted samples showed that increasing the acid washing time from 5 min to 10 min in the second acid solution results in a rough titanium surface with smaller surface pores. In order to enhance the hydrophilicity of the surface and thus, to reduce the stabilization time of the implants in the dental cavity, the samples were exposed to various surface treatments such as nitrogen plasma, liquid nitrogen washing, visible light irradiation, and hydrothermal treatment. Then the samples were stored in 5X    solution in nitrogen atmosphere for 5 months. After that, hydrophilicity, protein absorption, cell culture, MTT, and antibacterial tests were performed on the samples. XRD analysis performed after hydrothermal treatment also showed that the structure of titanium has changed to anatase phase. Hydrophilicity tests showed that the wetting angle of all the samples is less than 10?. Therefore, it can be concluded that superhydrophilic properties have been achieved in all the titanium samples. Nitrogen plasma and hydrothermal treatment showed the most effect on the superhydrophilic properties. In addition, the highest protein adsorption (0.110) and cell adhesion was achieved after hydrothermal treatment. The results of antibacterial test also showed that surface activation methods have no significant effect on antibacterial properties.

   پيشرفت در صنعت ساخت و افزايش ميل مردم به سكونت در مراكز متراكم شهري ، همواره مهندسين را به سمت ساخت     سازه هايي با حداكثر زير بناي مفيد سوق داده است كه اين كار تنها با افزايش طبقات روسازه و زير سازه امكان پذير خواهد شد . روش نوظهور ساخت سازه از بالا به پايين[1] به دو صورت متداول جهاني و رايج در ايران در حال توسعه مي باشد كه اختلاف عمده آن در شيوه اجراي ديوار حائل پيراموني است . در اين پايان نامه با مدل سازي يك سازه مناسب به دو شيوه نام برده شده به صورت محاسبات عددي و روش اجزاي محدود ، در برنامه پلكسيس سه بعدي[2] ، بررسي هاي لازم پيرامون ايمن بودن و اختلاف در مقدار تغيير شكل ديواره گود به دو روش رايج در ايران و متداول جهاني صورت گرفته است . از نتايج حاصل برداشت شد كه جابجايي ديواره گود در سازه هاي ساخته شده به روش   نام برده شده رايج در ايران بيشتر از سازه هاي ساخته شده به روش متداول جهاني مي باشد و اين اختلاف در همه مراحل گود برداري و تمام تراز هاي منفي ( زير سطح زمين ) پا برجاست . با تغيير نوع خاك از درشت دانه به ريز دانه تر مي توان متوجه اين نكته شد كه اين اختلاف براي خاك هاي ريز دانه كمتر و براي خاك هاي درشت دانه بيشتر مي باشد   . براي تمام مدل ها مي توان گفت جابجايي ديواره گودبرداري شده براي روش ايراني تقريبا در حدود مجاز آيين نامه هاي معتبر و مبحث هفتم مقررات ملي ساختمان مي باشد اما به دليل نزديك بودن به حدود مجاز مي توان جهت افزايش ايمني از تمهيداتي همچون افزايش ضخامت ديوار حائل اجرا شده استفاده كرد . لازم به ذكر است ساير تغيير شكل هاي محتمل نظير نشست در زمين هاي اطراف و نشست قائم ديوار حائل اجرا شده به روش رايج در ايران بيشتر از روش متداول جهاني بوده كه به دليل حاشيه امن و فاصله زيادي كه از مقادير مجاز ايين نامه اي خود دارند ، اين اختلاف قابل چشم پوشي و ناديده گرفتن است .    [1] Top-down construction [2] Plaxis 3D

The current research is to present a new model for low noise amplifier design in wireless local area networks. For this purpose, we consider a low noise amplifier with cascode technique and then modify the cascade. The results of this study show that the modified cascade stage has high gain and optimal noise figure. The LNA will be designed to be stable in the 3.1 to 10.6 GHz range. The results of this study can be widely used in medical devices. The results of this research showed that the amount of noise in the designed circuit has been reduced by 45.57%. Also, the amount of gain in the circuit designed by the author has also increased by 20.5%. Therefore, it can be said that in the current research, satisfactory results have been obtained regarding reducing noise and increasing gain.   

  This research aimed to investigate the effect of graphene oxide on rheological properties of recycled vegetable oil-modified bitumen. Graphene oxide was added to pure bitumen PG 64-22 mixed with recycled vegetable oil in different concentrations of 0%, 0.3%, 0.6%, and 1%. Then, the rheological properties of the mixtures, including viscosity parameters, softening point, penetration, dynamic shear rheometer (DSR) test, direct tension test, and flexural beam rheometer (BBR) test were examined using laboratory tests. The results of the tests showed that adding graphene oxide to recycled vegetable oil-modified bitumen had a positive effect on its rheological properties. Based on the results, it can be concluded that graphene oxide can be used as an effective additive in improving the rheological properties of recycled vegetable oil-modified bitumen. Therefore, improving the rheological properties of recycled vegetable oil-modified bitumen using graphene oxide is proposed as a sustainable and economical method for improving the performance and durability of road paving.

A microelectromechanical switch is an electronic device that disconnects or connects electric current by changing the position or shape of its microscopic structure. These switches consist of micro and even nanometer structures and are used as an alternative to conventional electromagnetic switches in electronic devices. With the change the dimensions, the characteristics of the switch change. For example, by reducing, the response time is improved, as well as an increase in sensitivity to electric current occurs. Also, with the change, the application frequency was higher. Microelectromechanical switches are used in many electronic applications, including memories, sensors, electronic chips, and communication devices. It is also used in the automotive, medical and industry. In this thesis, the basic structure of switches based on micro-electromechanical systems for use in radio frequency has been investigated and analyzed, and the design challenges of different analyzes have been investigated in the analysis. Then, by evaluating the previous switches and previous examples, their results and the weak and strong points of each have been analyzed. Finally, a new microelectromechanical switch for high frequency applications has been designed and simulated using polysilicon material. The presented structure is operated with 5V voltage and its switching time is less than 38 microseconds. COMSOL version 6.1 software is used to simulate the proposed structure. One of the most prominent features of the provided switches is its size, which is only 60?m × 220?m, and this value is much smaller compared to other articles and designed switches. Also, one of the other terms in the design of high frequency switches is the value of capacitor at the time of the switch, or in other words, high capacitor and low capacitor, which is referred to as the capacitor ratio. This parameter for the presented switch is 65, which is very ideal and provides various applications for the switch. At the end, the presented switch structure has been modified and with the help of twisted anchors and different structures, different switches have been presented under the title of the first and second modified structure. Each of these structures moves with the same voltage of 5 volts, and for each of these structures, the structures of switching time, capacitance ratio, displacement, and the effect of contact force have been simulated and analyzed at the level of the switch. Also, the type of material in the function of the switch has been investigated and by changing the material to gallium arsenide, it is found that the contact forces on the surface of the switch are much less and the switching time increases.   

Due to their favorable biocompatible properties, titanium and its alloys are used as popular raw materials for making all kinds of implants. Therefore, the efficiency of the implant is always being developed in order to better adapt to the biological tissue and increase its retention time in the place of cultivation, in different ways that lead to the creation of an oxide layer on the surface. The aim of this research is to investigate the biocompatibility of titanium in different morphologies obtained from anodizing in alkaline and acidic electrolytes.  

   In this research, the influence of the design of openings and canopy on the energy consumption of residential buildings is investigated. First, the climate of Kermanshah city (place of building design) is analyzed using Climate Consult software and the available climate data, and an appropriate decision is made regarding the effect of orientation, color and other effective factors in design on reducing energy consumption. After defining the general strategies for the design in Kermanshah city, the focus is on radiation and shading, and using Design Builder and Ecotect software, the appropriate geometry of the window is selected in terms of natural light absorption. The dimensions of the windows should be such that it does not cause a lot of heat loss from the building. After determining the appropriate dimensions of the window, the location of the openings is determined according to the high-pressure and low-pressure areas of the building, so that in this way natural ventilation can be carried out in a desirable way in the building. In the continuation of the research, the design of the canopy is carried out, for this purpose Sun Tools software is used. The use of canopies is such that by reducing the cold load of the building, they will not cause shading in the cold days of the year and the heating load will not increase.

   Owing to the vital role of electrical energy in the daily lives of people, the stability of distribution networks after natural crises such as earthquakes is of particular importance. Aerial substations are among the most important equipment in distribution networks, and their proper seismic performance plays a significant role in the continuity of electricity flow during an earthquake. A review of the damage caused to the distribution networks by past earthquakes shows that the mentioned substations sometimes lack good seismic performance owing to design and construction weaknesses. In this thesis, the performance of distribution network aerial posts in previous earthquakes and existing standards in this field were reviewed and assessed. The objective of this thesis is to evaluate the seismic behavior of one of the aerial substations of the Kermanshah Province Electricity Distribution Company using finite element analysis. For this purpose, a 12 m long reinforced concrete pole with a nominal strength of 400 kgf was modeled using the finite element method in the Abaqus software. In the finite element model, the nonlinear stress–strain behavior of concrete is defined with the possibility of determining its damage index, and the stress-strain behavior of steel is introduced into the software with a bilinear curve. The finite element model was validated using the results of the static loading test of a 12 m long pole (available in the literature). Next, an aerial substation, a 315 kVA transformer (with a total weight of 1210 kgf) that was installed at a level of approximately 5 m from the ground level on a metal platform connected to two 9 m and 12 m long reinforced concrete poles, was introduced and modeled using Abaqus software. The transformer platform was connected to the 12-meter concrete pole of the post through two short C-sections that transferred the weight of the transformer to the pole by relying on the frictional resistance. Therefore, the contact surfaces between the concrete pole and the C-sections (as the support of the platform beam), which are prone to relative slip during earthquakes, were modeled in the finite element analysis. Considering that the studied aerial substation is located at the end of the line, the tensile force of the conductor wires connected to the concrete pole is applied as a static force in the finite element model on the 12 m pole of the substation. Finite element analysis includes a nonlinear time history dynamic analysis under the effect of the scaled accelerometer of the 2017 Sarpol Zahab earthquake, Iran, to document the weak point of the friction support of the transformer platform in transmitting seismic loads to its 12-meter base. The results of the analysis show that as a result of the relative slip at the contact surfaces of the C-sections and the 12 m long concrete pole, the transformer experiences significant rocking motions that could cause the risk of breaking the bushings and power outages during an earthquake. By examining the concrete poles of the post, it was observed that cracks and minor concrete crushing failures occurred at the base of the pole. Despite the damage to the concrete in this area, the pole maintained its stability and did not fail.

      In recent years and with the increase in the number of elderly people in different countries, the supply and demand for the use of titanium and its alloys in the manufacture of implants used in the human body such as hip joint prosthesis, joint replacement, knee replacement, fracture fixation and dental implants have increased.   has increased widely.   In medical applications, in addition to the usual properties of alloys, other factors such as topography and surface energy are also considered, which play an important role in the adhesion of bone cells to the implanted surface.   As a result, the surface of the material plays an important role in the body's response to the implantable material.   The purpose of this research is to investigate the effect of some variables of the sandblasting process, acid washing and heat treatment on the surface characteristics and cellular response of titanium.   In order to modify the surface of the titanium substrate, first the samples were sandblasted using alumina powder, then they were etched in a solution containing nitric acid and sulfuric acid for the necessary time.   After that, the samples were placed in the oven at temperatures of 300, 400, and 500 degrees Celsius for one hour. A group of samples were left without heat treatment.   In order to measure roughness, hydrophilicity, investigate surface morphology, investigate phase compounds, cytotoxicity and biocompatibility of substrates, various tests and equipment including roughness meter, water contact angle measurement system, XRD, cytotoxicity and SEM were used to investigate cellular morphology.   The results of the X-ray diffraction test showed that the dominant phase formed is the Ti6O phase.   Of course, a small amount of Ti2O3 was also formed.   The above groups cause better calcium deposition through reaction with body fluids.   And the results of the hydrophilicity test showed that the amount of wetting angle ?m decreased with increasing sandblast pressure and especially with heat treatment compared to the control samples.   However, in most of the samples, by increasing the temperature of heat treatment to 500 degrees Celsius, the contact angle has increased and the wettability has decreased.   Regarding the evaluation of cell viability, the produced levels did not show any signs of cytotoxicity.   In fact, the roughness of the surfaces obtained after sandblasting and acid etching were able to strengthen the attachment and proliferation of MG-63 cells on their surfaces.

Aluminum 3819 due to its good corrosion resistance and high strength-to-weight ratio in marine, military, pipe- It is widely used in pressure vessels, shipbuilding, refrigeration industries, oil rigs and gas transmission lines. among All aluminum alloys, alloy 3819 for all welded assemblies, tanks with the highest welding efficiency and maximum strength, connection of marine equipment, bridges, cargo ships, heavy ships and marine organizations, TV masts, grinding equipment, recycling machine body transfer equipment and wherever needed Corrosion resistance equipment is widely used. A Ag/Sn/Ag system to Shar et al connected with ultrasonic assistance and concluded that the acceleration of Ag atomic penetration with ultrasonic assistance is 6 3 times faster - - than the traditional TLP connection. Gio et al. fine-grained 4897 aluminum alloys with zinc interlayer TLP method with the help of ultrasonic bonding and reported that long ultrasonic time increases Zinc penetrates into aluminum. Li et al. for bonding Ag/Mg using ultrasonic assisted TLP method used and obtained the optimum shear strength of 68 MPa in a short period of 7 seconds. At This research has examined the TLP connection with the help of ultrasonics. This type of connection can not only connect with It provides high mechanical properties but also acts as a low temperature joining method. TLP with help Ultrasonic does not need shielding gas and can accommodate complex structures. Until today TLP It is used to connect different materials with the help of ultrasonic.  

Review : There are various methods of surface coating to deal with corrosion and wear and other surface damage. One of the easiest and most economical coating methods is electroplating or electroplating. In the past, the best element for electroplating coating was chromium, but today, due to the toxicity of the ions obtained from the chrome plating bath, nickel is used instead of this element. Nickel coating is alloyed with elements such as tungsten, molybdenum, cobalt, etc. for better properties. One of the innovations that has led to the production of coatings with better properties and performance is composite coating through the deposition of base and reinforcing nanoparticles. TiO2 and SiC hard nanoparticles are among the most widely used nanoparticles for creating composite coatings. The simultaneous presence of these Nanoparticles in the coating, if they are properly dispersed, can give the coating good chemical and physical properties. In this research, nickel-tungsten coating along with TiO2 and SiC nanoparticles were applied with direct plating current on the substrate of low carbon steel and their wear and corrosion behavior was investigated. The effect of variable Ph parameters, plating time, plating current density, the amount of nanoparticles in the plating bath, and the presence of ultrasonic waves during plating were investigated. In order to check the wear resistance of the pin on the disk, the corrosion resistance of the polarization test was used to determine the existing phases as well as the grain size by X-ray diffraction patterns (XRD) and to check the microstructure of the coating by field emission scanning electron microscope (FESEM). The results showed that for nickel-tungsten coating, the optimal pH is 7.5 ± 0.5 and the optimal current is 200 mA/cm2. Adding TiO2 nanoparticles to the plating bath increased the wear and corrosion resistance as well as the hardness of the coating and reduced the size of the crystals. Adding SiC nanoparticles to the bath led to an increase in hardness and wear resistance, as well as a decrease in crystal size and corrosion resistance. Coating in the presence of ultrasonic waves with powers of 40 and 60 led to an increase in the abrasion properties and hardness of the coating, but the increase in the power of the ultrasonic waves led to a decrease in these properties, which is due to the distortion and removal of particles from the surface of the coating due to the high power of the ultrasonic waves. is. In all the powers of the ultrasonic waves, the corrosion resistance decreased due to the cracks in the microstructure.   

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The stability of seismic earth dams is particularly critical to the integrity of downstream areas. This thesis describes a numerical study related to both the seismic response and the analysis of earth dams using the finite element method. In this thesis, we will study the effect of the hydrodynamic stresses of an upstream reservoir on the elastic seismic response of dams. A methodology will be proposed in which the reservoir field is modeled with a particular focus on the accurate prediction of the hydrodynamic pressures on the upper dam face. The main part of the thesis is related to the study of the design of the Shehabi dam under study and their hydrological and historical seismic data, which will be analyzed in order to validate the numerical model and get a good agreement between the recorded and projected data. Obtaining dam response during an earthquake with different acceleration and duration using Geo-Studio Seep/w and Quake/w software. Subsequently, using as a reference the calibrated model, parametric studies are performed in order to obtain a better insight into the dynamic response and analysis of the response of the embankment of the dam under consideration during an earthquake with different acceleration, duration and water reservoir level. It is better that we will conduct a three-dimensional seismic analysis of the Shehabi dam by adopting the initial values of the shear stiffness. This will enable insight into the effects of the dam-valley interaction it will confirm whether the \\amount" of stiffening adopted in this study is appropriate.

باكاهش منابعآب قابل مصرف و تنش آبي رو به افزايش درساير نقاط جهان ، توسعه روش‌هاي مختلف  جهت مديريت كارآمد اين ماده حياتي، اهميت ويژه‌اي پيدا كرده است. كاهش حجم آب به حساب نيامده از مهمترين روش‌هاي مديريت مصرف آب محسوب مي‌شود. نشت كه به عنوان اصلي‌ترين موئلفه آب به حساب نيامده شناخته شده است،   نه تنها يك مساله اقتصادي، بلكه مساله‌اي زيست ‌محيطي و به طور بالقوه يك مساله بهداشتي و ايمني مي‌باشد كه كاهش ميزان آن در سيستم‌هاي آب‌رساني را مي‌توان يكي از اهداف عمده سازمانهاي تأمين و توزيع آب به‌ شمار آورد. در تحقيق حاظر از يك تكنيك هوش مصنوعي تحت عنوان ماشين يادگيري افراطي (ELM) جهت يافتن محل و ميزان نشت در شبكه توزيع آب استفاده شده كه با توسعه اين روش برخي از   محدوديت‌هاي استفاده از تكنيك‌هاي هوش مصنوعي منجمله تعداد خروجي مدل‌هاي‌ يادگيري ماشيني رفع شده و همچنين فرآيند اجرا كه در اكثر اين تكنيك‌ها در مواجه با داده‌هاي با ابعاد بزرگ امري نسبتا زمان‌بر است در مدل   ELM بكار رفته كاهش يافته است. در اين تحقيق همچنين از يك مدل شبكه عصبي پرسپترون چند لايه MLP جهت مقايسه نتايج و عملكرد آن با مدل ELM   استفاده شده است. روش‌ها بر روي يك شبكه توزيع   آب فرضي و كاملا حلقوي موسوم به شبكه توزيع آب پولاكيس اعمال شدند. نتايج بدست آمده نشان مي‌دهد روش بكار رفته كه در آن ماهيت وابسته به فشار نشت حفظ شده است، با حداقل برداشت اطلاعات هيدروليكي از نوع فشار گرهي، علاوه بر شناسايي موقعيت گره‌هاي نشت‌دار، محل و ميزان نشت گرهي كه نشت كمتري را دارد با دقت بالايي پيش‌بيني كند.  

   Abstract Today, pollution of aquatic ecosystems with a wide range of organic and inorganic pollutants has become one of the biggest human challenges, so that research studies examining techniques and the use of effective attractants in reducing and Or the elimination of some of these harmful pollutants, including arsenic, has many study priorities. The aim of this study was to optimize the adsorption conditions of arsenic heavy metal from water using magnetite-chitosan composite nanosorbent. The advantage of using chitosan coating is higher adsorption capacity and higher stability of adsorbent nanoparticles and its easy separation from aqueous solution. In this study, first magnetite nanoparticles were synthesized by co-precipitation method of iron (II) and (III) chloride ions and the obtained nanoparticles were first identified by FT-IR spectrum, then UV-Visible spectrum, TEM, XRD, VSM. , DLS, Zeta potential were obtained. After reviewing the results and obtaining the result, carboxymethylcytosans were sonochemically bonded to the surface of the modified magnetite nanoparticles and the surface of the magnetite nanoparticles was coated with carboxymethylcytosane. Magnetite-chitosan composite nanoparticles were taken by material analyzers, first FT-IR, UV-Visible, XRD which showed the presence of magnetite with chitosan coating, then TEM, VSM images, magnetic saturation change of nanoparticles after coating Delivery, DLS particle size distribution and Zeta potential surface load were investigated. Then, the adsorption test was performed using Design Expert software and the experiment was designed with Taguchi model from four factors: adsorbent dose, pH, temperature and time, and arsenic solution with an initial concentration of 1 ppm. Residual arsenic concentration was measured by ICP-Mass and statistical operations were performed on the test results and the effect of various factors on the adsorption efficiency was shown as contours so that the adsorption efficiency increased with increasing adsorbent dose and with increasing pH of The adsorption efficiency increased from 3.5 to 8.5 at a certain dose and the increase in temperature and time also increased the adsorption. Dose was 0.0300 g and pH = 3.5, contact time was 1440 min and temperature was 35 ° C. The optimal absorption point with 99.3% yield was obtained at a dose of 0.0283 g and pH = 6.4, and the contact time was 976 min and the temperature was C38, and the validation test showed a value of 99.4%. The weight ratio of chitosan to magnetite was synthesized in four different ratios of 1: 1, 2: 1, 3: 1 and 4: 1, and in optimal adsorption conditions, a test was performed. . Using the linear, nonlinear Langmuir equations and then the linear and nonlinear Friendlich isotherms, the isotherm that was consistent with the adsorption process and showed the highest correlation coefficient was the linear Langmuir and Friendlich isotherms, which obtained the maximum absorption capacity from the equation. The magnetite-chitosan composite was calculated to show 313.57 mg / g. According to the obtained results, the synthesized nanocomposite can be used for water filtration and arsenic adsorption under optimal conditions.

  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.   

synthesis and Characterization of core-shell nanoparticles(YSZ@Ni nanoparticles)

study

بررسي كارايي حرارتي مبدل صفحه ايي با استفاده از نانو سيال

  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  

  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.  

طراحي يك تقويت كننده كم نويز و بهينه سازي تابع نويز توسط الگوريتم هاي بهينه سازي در متلب