Due to the significant share of the building sector in total energy consumption, investigating innovative methods to reduce energy use and enhance energy efficiency in this sector is of particular importance. One of the effective approaches in this regard is the use of phase change materials (PCMs) to improve the thermal performance of the building envelope. In this study, the performance of six types of phase change materials with five different thicknesses (ranging from 0.01 m to 0.05 m) was simulated using EnergyPlus software for a 48 m² residential building located in Kermanshah, during the period from November to March. The results showed that the building’s heating load, which was 3914.38 kWh in the reference case, decreased to 3601.94 kWh after incorporating PCM. The highest reduction in heating load, equal to 312.43 kWh, was achieved with paraffin RT21, which has a melting temperature of 21 °C, corresponding to 7.98% energy savings. Furthermore, it was found that increasing the PCM layer thickness beyond 4 cm had no significant effect on improving thermal performance, and the greatest impact of PCM occurred when it was applied to the inner layer of the building envelope.

Abstract Hydrogen production as a clean and sustainable energy source, particularly through water splitting, is considered one of the fundamental challenges in the field of renewable energy. In this study, the process of hydrogen production through photocatalytic water splitting using photocatalysts Bi?WO? and CuBi?O? with different weight ratios is investigated and analyzed. The two photocatalysts, CuBi?O? and Bi?WO?, were synthesized via a hydrothermal method and subsequently combined in various weight percentages. Due to their unique properties in light absorption and charge transfer enhancement, these photocatalysts have the potential to exhibit high efficiency in hydrogen production from water. To characterize the Bi?WO? and CuBi?O? photocatalysts, several analytical techniques were employed. Subsequently, the impact of forming a heterogeneous junction between these two materials on water splitting performance was examined. All reactions were conducted under UV-Visible light in a 160 mL quartz reactor. Experimental results indicate that although the pure Bi?WO? and CuBi?O? photocatalysts produce hydrogen at rates of 131.87 ?molg?¹ h?¹ and 165.56 ?molg?¹ h?¹, respectively, the heterogeneous Bi?WO?/CuBi?O? junction in the optimized sample significantly increases the hydrogen production rate to 341.25 ?molg?¹ h?¹ compared to the individual photocatalysts. This enhancement in efficiency is attributed to improved light absorption, increased electron and hole lifetimes, and reduced electron recombination.   Keywords: Photocatalyst, CuBi?O?, Bi?WO?, Water Splitting, Heterojunction

   Abstract Oxidative desulfurization (ODS) is a promising method for replacing the traditional hydrogenation desulfurization process. High selectivity in removing refractory organic sulfur compounds, low cost, and milder operating conditions are the most important advantages of this desulfurization method, which has attracted the attention of many researchers in recent decades. In this research, a 3%Mn-15%MoO3/?-Al2O3 bimetallic catalyst along with H2O2 as an oxidizing agent and DMF as a solvent were used to remove organic sulfur compounds by oxidative desulfurization. For this purpose, the mesoporous 3%Mn-15%MoO3/?-Al2O3 catalyst was synthesized using the wetness impregnation method. The synthesized catalyst was characterized using XRD, FTIR, FESEM, EDS-MAPP, and BET tests, showing that the catalyst with 15%Wt MoO3 (as the active metal) and 3%Wt Mn (as the promoter metal) exhibited the best performance for oxidative desulfurization. Subsequently, the operating conditions were optimized using Design Expert 11 software and the CCD(central composite design) method to achieve the highest desulfurization efficiency. The highest desulfurization efficiency was achieved at an O/S molar ratio of 3.4, a catalyst loading of 1.1 grams for 3%Mn-15%MoO3/?-Al2O3, a reaction temperature of 60.2°C, and a reaction time of 30 minutes. Additionally, under these optimized conditions, the ODS process was performed on sour gas oil and fuel oil cuts produced by the Lavan oil refinery, resulting in desulfurization efficiencies of 58% and 44%, respectively. These efficiencies were expected due to the higher concentration and complexity of sulfur compounds present in these cuts. Finally, the 3%Mn-15%MoO3/ ?-Al2O3 catalyst underwent five regeneration cycles, and the results demonstrated that the catalyst maintained its activity well and can be reused after five regeneration cycles.    Keywords: desulfurization, Oxidative desulfurization, Bimetallic Catalyst, Wetness Impregnation,   Modeling And Optimization.   

In this research, desulfurization through an adsorption method using activated carbon derived from oak seed husk was investigated for a model fuel consisting of n-hexane solvent and the sulfur compound dibenzothiophene. The activation process utilized chemical activation with phosphoric acid. The adsorption process was conducted in a batch system, and the nitrogen adsorption-desorption isotherm for the synthesized sample was >  

   In the characterization of C7+ fractions with wide boiling ranges, measuring distributed properties such as molecular weight (MW), specific gravity (SG), and true boiling point (Tb) can be time-consuming and expensive. This thesis aims to analyze oil data using Solver in Excel and neural network in Matlab to improve the accuracy of oil properties prediction. The data consists of 68 oil samples. The data were divided into two groups: black oil and condensate gas. the Solver tool in Excel to determine the parameters A, B, and P0 for each property P such as SG, MW and Tb in Riazi distribution model Solver program was also used to analyze the data and find the average percentage of the average absolute deviation (AAD%) for both black oil and condensate gas and for each property of SG, MW and Tb. The neural network was then trained using the bulk inputs of MW and SG, along with XC values ranging from0.1 to0.99. By fine-tuning the neural network, the distributed properties of SG, MW, and Tb could be predicted with high accuracy. The study aimed to reduce the complexity and cost associated with measuring distributed properties by utilizing computational tools like Solver and neural networks. So, it was possible to predict the distributed properties of heptane plus fractions with minimal empirical data. The results showed that the neural network model achieved a mean square error ·   (MSE) of (0.0258) for the gas condensate ·   (MSE) of (0.0976) for the black oils. This indicates a high level of accuracy in predicting the distributed properties of SG, MW, and Tb based on the bulk properties. In addition, a second neural network was used to verify the accuracy of the prediction made by the first network with inputs MWb,SGb,XC and outputs (Predicted outputs in the first network) and the mean square error was calculated for both condensate gas and black oil.    ·   (MSE) of (0.003746) for the gas condensate ·   (MSE) of (0.009242) for the black oils. Overall, the utilization of neural networks for the characterization of heptane plus fractions represents a promising approach to streamline the characterization process and reduce time and cost. By leveraging computational tools and machine learning techniques, researchers can enhance the efficiency and accuracy of characterizing complex hydrocarbon fractions.

  synthesis of supported Monolith with Honeycomb method and Characterize Structural investigation

The goal pursued in this research is to increase the photocatalytic performance of Ag2CrO4(ACO) under visible light irradiation to remove alizarin red (AR) color pollutant. Due to the narrow energy gap and also the recombination rate of this photocatalyst, its photocatalytic performance decreases. To solve this problem, NiFe-LDH photocatalyst, which is a member of the double-layer hydroxide family, was used along with ACO. Three composites with different molar percentages (AN1-1: AN2-1: AN1-2) were prepared, among which composite (AN1-1) Ag2CrO4@50% NiFe-LDH50% was the best sample with a removal rate of 97.1% in AR degradation. . Also, the properties, structure and characteristics of pure Ag2CrO4 and NiFe-LDH and their composites were determined by XRD, FESEM, FTIR, EDX mapping and UV-Visible analyses. It was found that Ag2CrO4@NiFe-LDH composites with the Z design structure, in addition to increasing the active sites and increasing the specific surface area, reduce the recombination rate of pure Ag2CrO4 and NiFe-LDH. From the technique of designing Box Behnken experiments, which is one of the most commonly used designs in response surface methodology (RSM), to optimize operating conditions and investigate the effect of 4 independent parameters: catalyst amount (0.5-1.5 g/L), solution concentration (5 -20 mg/L), pH (12-4) and light intensity (52-13 W) were used. The importance of independent parameters and their interaction was determined using ANOVA. Using numerical optimization, the optimal values of the selected parameters equal to 1.34 g/L of catalyst, solution concentration of 16.45 mg/L, pH = 10.74 and light intensity of 15.53 W were obtained as optimal conditions with a desirability coefficient of 1.00 and an absorption value of 95.71%. The closeness of adjusted R2 (0.9838) and predicted R2 (0.9507) values show that this model can be successfully used for prediction. Also, after 3 cycles, the degradation efficiency of AN1-1 decreased by only 8.16% and no significant deactivation was observed, indicating the high stability and remarkable reusability of the photocatalyst; Therefore, the prepared composite can be suitable for the photocatalytic removal of wastewater containing colored pollutants.  

In thisstudy, the efficiency of an advanced photocatalytic oxidation process for theremoval of Methylene Blue (MB) dye from synthetic wastewater wasinvestigated.     composiwas used, and the process was examined under visible light irradiation. Tooptimize the conditions for photocatalytic decomposition, the Box-Behnkendesign method was employed. -   compositeswith different molar ratios (1:2, 1:1, 2:1) were synthesized using thehydrothermal method. The highest photocatalytic removal efficiency in theinitial experiments was found to be 85%, attributed to the BC-2:1 composite.XRD, FTIR, FESEM, EDX, and UV-Vis analyses were employed to identify thestructural and optical properties of the synthesized photocatalysts.FE-SEMshowed relatively uniform distribution of copper oxide (CuO) nanoparticles onbismuth chromate ( ) nanotubes. UV-Vis analysisindicated that the highest photocatalytic performance was achieved by theBC-2:1 composite, with a band gap of approximately 1.73 eV compared to thelower performance under visible light irradiation of pure CuO and . This enhanced photocatalyticactivity can be attributed to the heterogeneous p-n synergistic effect. Pure   and CuO samples individually were not capableof effectively performing the photocatalytic reaction for Methylene Blue (MB)removal. However, the composite samples exhibited highly desirablephotocatalytic activity. Photodegradation experiments were conducted with theproposed optimal parameters, including an initial MB concentration of 18.89mg/L, a pH of 11, a catalyst dose of 0.99 mg/L, and a light intensity of 29.2W. The suggested system's response (percentage removal) was 91.97%.The averagepercentage removal of the dye, based on three repeated measurements, was90.06%, indicating the applicability of the proposed model. Furthermore, the -

   Currently, removing sulfur from gas or liquid fuels is one of the most important tasks of the oil refining industry. Sulfur compounds such as mercaptans, thiophenes, benzothiophenes, and dibenzothiophenes can be converted into SOx during gas or liquid combustion. Various physical, chemical and biological methods have been investigated in order to remove sulfur impurities from petroleum compounds, which include HDS, ADS, BDS, EDS and ODS. In this research, the oxidative desulfurization process of simulated oil cut containing 1000ppm di-benzothiophene using heterogeneous catalysts with loading of potassium tungsten oxide based on natural kaolin zeolite along with hydrogen peroxide as oxidizing agent and acetonitrile as solvent. The extraction was done in which catalysts with 5, 10, 15, 20% by weight of potassium tungstate based on metakaolin were made by dry inoculation method. After testing the %W catalyst /metaKaolin 15 was chosen as the best catalyst in this research . Then, using Design Expert version 11 software, the experiments were designed and the optimal operating conditions (t=60min, T=60Co, O/S=12, cat=0.04g) were determined and the amount of desulfurization from the model oil in these conditions 98.9% was obtained. Also, the corresponding catalyst still had an acceptable performance after five recovery steps.

   Gas refineries after sweetening and dehumidification processes, with the problem of presence of mercaptans in the gas stream. are facing considering the importance of separating mercaptans from natural gas flow due to the harmful environmental effects and Improving the quality of products of gas refineries, the mercaptan removal process of one of the most important refinery units. is counted The removal of mercaptans from gas streams is done by various methods that use Surface adsorption processes are among the most widely used methods. In this research, simulation of mercaptan removal unit Phase one of the South Pars gas company, which uses surface absorption technology, has been completed. In this unit, from The surface adsorption operation is done by alternating pressure-temperature method (PTSA) using 13X and 3A zeolite adsorbents. The importance of the mercaptans removal process is clear and any increase in separation efficiency will lead to improved unit performance. Therefore, in this research, a new process cycle, which includes two stages of temperature equalization to reduce temperature and pressure equalization to increase pressure, was presented in order to improve the performance of the process, and the effect of effective parameters on the quality of the output product was also investigated. . The simulation of the unit was done using Aspen Adsorption software. The values ??of the mole fraction of the components in the output flow of the simulated model were compared with the real data and the average relative error was 1.23%. The results of the simulation showed that in the studied operation, cyclic dynamic conditions occur after five consecutive cycles from the beginning of the process. The concentration of methylmercaptan and water decreases from the input values ??of 1100ppm and 30ppm to the final values ??of less than 9ppm in dynamic cyclic conditions (DCS). In addition, using the new proposed cycle reduces the power consumption of the unit. . so as to reduce the energy consumption of the existing unit by 35.43%. The effect of the effective parameters on the quality of the output product, including the flow rate of the input feed as well as the temperature of the second heating stage was investigated on both the existing and improved cycles and the results showed that by reducing the temperature of the second heating stage to 175°C and reducing the feed flow rate Input at the rate of 2.3 kmol/hr achieves the highest separation benefit for both cycles.         

  فرآيند كاتاليزوري   با استفاده ازتترا كلريد تيتانيوم   وديگر تركيبات وابسته، رايج ترين پروسه توليدي براي چرخه زيگلر ناتااست.روش هاي ديگري در اين چند وقت اخير ابداع شده اند كه همگي منتج به توليد وپليمريزاسيون گشته است ولي رايج ترين و در دسترس ترين روش و بومي سازي شده ترينروش، همين روش مي باشد.اين روش با توجه به تثبيت شدن در تمام جهات اكنون روشياقتصادي مي باشد و از همه لحاظ توجيه پذيري اقتصادي دارد كه مي توان   به بومي سازي شرايط آزمايشگاهي،به وفور در دسترس بودنتجهيزات آزمايشگاهي ،ساخت پلنت هاي متعدد توليدي ،بازدهي بالاي توليد محصول وپليمريزاسيون و... نام برد ولي با توجه به ماهيت پژوهشي علم و اينكه هميشه بهدنبال راهي براي بهبود يافته ها و دستاوردهاي قبلي مي باشد سعي شده كه نقاطضعف   يافته هاي قبلي پوشش داده   شده و به بهبود و خلق پيشنهادات جديد بپردازد.در ابتدا با اضافه كردن كردن عناصر فلزي مانندFeCl3   و SiCl3 در فاز گازي[22] ،كاتاليزورهايي را ساخته و به وسيله روش ودستگاههاي آزمايشگاهي از قبيل SEM،   ETو EDX تاثير اينعناصر بر افزايش فعاليت كاتاليست مورد بررسي قرار گرفتند.سپس در فاز دوغابي واكنش مورد بررسي قرارگرفت.در انتهاي نتايج بررسي در جدولي مقايسه ايگردآوري و جمع بندي گرديد.بحث پاياني كه مهمترين و اصلي ترين موضوع اينپژوهش و شاكله اصلي آن مي باشد به اصلاح و افزايش واكنش پذيري كاتاليست هاي زيگلرناتا مي پردازد.با توجه به وجود الكل و حلال هگزان در چرخهواكنش و توليد كاتاليست ، وجود آلودگي ها و آلكوكسي ها در واكنش اجتناب ناپذير ميباشد.آلكوكسي ها باعث تخريب واكنش اصلي و انجام واكنش كاذب و متعاقبا عدم ايجادزنجيره پليمريزاسيون و توليد پليمر ميگردند.لذا بايستي آلكوكسي ها   به حد قابل قبولي كه نقطه تعادلي بين واكنشپذيري و اقتصادي بودن واكنش باشد كاهش يابند.براي اين منظور روش جديد شستشوي كاتاليستابداع گرديده است.ابتدا با نمونه گيري 6 متر مكعب از پايه كاتاليستمحلول در هگزان شروع به تعيين دماي نقطه ابتدايي آزمايش   است مي نماييم.اين دما اندكي كمتر از نقطه جوشهگزان است. نمونه گرفته شده را به آزمايشگاه منتقل كرده و مو پس از تهيه سياليكدست و كاملا حل شده ، پس از تبخير حلال ،آن را به پودر كاتاليست تبديل مي نماييم.پودرحاصله را پس از تبديل به قرص به دستگاهIR جهت تشخيص ميزان آلودگي به آلكوكسي ها منتقل مي نماييم ونتايج حاصل را ثبت و ضبط مي نماييم. سپس بطور متوالي 14 مرحله ديگر را همين ترتيبكه نمونه را در بازه دمايي بعدي تا توليد قرص كاتاليست پيگيري نموده و جهت تست واندازه گيري آلكوكسي به آزمايشگاه ميفرستيم.با آناليز نتايج حاصله دستگاه IR   مشاهده ميشود كه نرخ كاهش از مرحله پنجم به بعدبشدت كاهش يافته زيرا اغلب آلودگي آلكوكسي ها  در همان پنج مرحله ابتدايي كاهش يافته و نرخ كاهش بعد از مرحله پنجم باتوجه به مقدار هگزان مصرفي و مقوله اقتصادي آن قابل اعتنا نمي باشد.لذا شرايط فرآيندي مرحله پنجم شستشو كه دماي55 درجه و ميزان مجاز الكوكسي 100PPM     مي باشد را به عنوان مبنا انتخاب نموده و از اينبه بعد براي رسيدن به ميزان100 PPM تا پنج مرحله شستشو مي دهيم.  

  Abstract

پارامتر بسيار حائز اهميت است.   

   سوخت­هاي بيوديزل به علت خاصيت تجديدپذيري و آلايندگي كمتر امروزه در معرض توجه بسياري از كشورهاي دنيا و علي الخصوص كشورهايي كه با بحران منابع سوختي درگير هستند مي­باشد. اين سوخت ها كه از منابع متنوعي همچون روغن­هاي گياهي، چربي­هاي حيواني و جلبك ها به دست مي­آيند، با ديزل معمولي تركيب شده و در موتور خودروها مورد استفاده قرار مي­گيرند. با توجه به تنوع تركيب ديزل/بيوديزل نيازمند توسعه مدل­هايي براي اندازه­گيري خواص اين مخلوط ضروري مي­نمايد كه اين مدل مستقل از نوع بيوديزل باشند. يكي از بهترين روش­هايي كه امروزه براي توصيف روابط رياضي پيچيده و يا پارامترهايي كه داراي رابطه رياضي خاصي نمي­باشند، استفاده از شبكه­هاي عصبي مي­باشد. عدد ستان و ويسكوزيته، دو مورد از خواص بسيار مهم بيوديزل هستند كه جز شاخصه‌هاي اصلي كيفيت سوخت به شمار مي‌روند؛ بطوريكه هر چه عدد ستان بيشتر باشد، كيفيت سوخت بيشتر بوده و هر چقدر مقدار ويسكوزيته آن كمتر باشد، سوخت به سهولت در موتور خودرو جابجا شده و بازدهي آن بالاتر خواهد بود. در اين پايان­نامه با استفاده از ساختارهاي متفاوتي از شبكه­هاي عصبي شامل الگوريتم­هاي آموزش مختلف (لونبرگ ماركوات، كاهش گراديان، BFGS، گراديان مزدوج)، توابع فعال ساز گوناگون (logsig، tansig، radbas، purelin) و تعداد نورون­هاي متغير از 1 تا 20 به محاسبه مقادير ويسكوزيته سينماتيك و عدد ستان مخلوط ديزل/بيوديزل پرداخته مي­شود. در اين پايان­نامه از 6 نوع بيوديزل مختلف استفاده شده است كه خواص درصد حجمي بيوديزل، عدد ستان بيوديزل ، دماي جوش، دماي تبخير، دماي فلش، دماي ريزش، گرماي احتراق، دماي ابري شدن، ويسكوزيته سينماتيك و وزن مخصوص آن­ها در دسترس مي­باشد. براي محاسبه ويسكوزيته سينماتيك و عدد ستان مخلوط، از تركيب­هاي متنوعي از ورودي­ها (دومتغيره و سه متغيره) استفاده شد تا بهترين آن­ها به دست آيد. نتايج نشان داد كه يك شبكه عصبي با الگوريتم لونبرگ ماركوات، تابع فعال ساز purelin، تعداد نورون 7 و با دو ورودي درصد حجمي بيوديزل خالص و ويسكوزيته سينماتيك بيوديزل خالص داراي مقادير ضريب همبستگي 9957/0 و ميانگين مربعات خطاي 0054/0 بيشترين برازش را با داده­هاي آزمايشگاهي ويسكوزيته سينماتيك مخلوط دارد. همچنين با در نظر گرفتن سه متغير ورودي درصد حجمي بيوديزل، ويسكوزيته سينماتيك و وزن مخصوص بيوديزل ميزان ضريب رگرسيون برابر 9947/0 و ميانگين مربعات خطا برابر 0063/0 به دست مي­آيد كه مدل مناسبي به شمار مي­رود. نتايج محاسبه عدد ستان مخلوط نيز نشان داد كه در حالت ورودي دو متغيره (درصد حجمي بيوديزل و عدد ستان بيوديزل)، يك شبكه عصبي با الگوريتم لونبرگ ماركوات، تابع فعال ساز tansig و تعداد 10 نورون و مقدار ضريب رگرسيون 9803/0 و ميانگين مربعات خطاي 4247/0 بيشترين سازگاري را با داده­هاي آزمايشگاهي دارد. با اين حال با فرض ورودي سه متغيره (درصد حجمي بيوديزل، عدد ستان و دماي ابري شدن) و با الگوريتم آموزش لونبرگ ماركوات، تابع فعال ساز tansig و تعداد 8 نورون و مقدار ضريب رگرسيون برابر 9903/0 و ميانگين مربعات خطا برابر با 2968/0 مي­باشد كه بيانگر مدل بهتري نسبت به حالت ورودي دو متغيره مي­باشد. نتايج ساير ورودي­ها در خلال پايان­نامه آورده شده است.    كليدواژه‌ها: شبكه عصبي، مخلوط ديزل/بيوديزل، مدل سازي، پيش‌بيني خواص.   

Managing the disposal of waste hydrocarbon gases in industrial complexes is one of the most important issues for industrial units due to global warnings to reduce the long-term dire consequences for the ecosystem and its economic losses. A significant portion of the waste gases sent to the burner are light gaseous compounds such as methane, ethane, propane and four carbon and hydrogen inclusions, which by recovering them, not only the release of combustion products into the environment and its harmful consequences can be avoided, but also global warming and over-consumption of economic resources can be prevented. In the present study, GTL process simulation and optimization are investigated among other burner gas recovery methods due to the production of more high-quality products and better process economy. In this method, in addition to recovering heavy hydrocarbons, methane gas is converted into valuable materials such as gasoline, LPG or LNG with a lower sulfur content than usual. This process was further enhanced by the addition of a membrane unit, which increased hydrocarbon production by 13% to justify the increased fixed and operating costs of the membrane unit. Also, by returning the water leaving the membrane to the reforming reactor, the amount of water vapor requested from the water, electricity and steam unit is reduced by 92%. Furthermore, carbon dioxide produced by GTL reactor in reforming reactor is used to increase the production of synthesized gas by up to 7%.   

AbstractToday, the issue of pollutants in water resources such as organic matter and minerals is of great importance. Among the available water pollutants, paints, which are a group of organics with a complex structure and enter the environment through various processes such as dyeing, can be considered as the main sources of water pollution.According to research on the removal of dyes from water sources, photocatalytic degradation (a branch of the advanced oxidation process) is an efficient and low-risk method or the so-called green. Among the photocatalytic compounds developed, the two compounds zinc oxide and titanium dioxide are known to be more widely used, so-called more industrial, because of their cost-effectiveness, high jump, no pollution, and low energy requirements. Zinc oxide compound, which is white and environmentally friendly, is a non-toxic compound with high stability, high light sensitivity, wide energy gap and photocatalytic properties and high efficiency, which has attracted much attention in electron production.Pure photocatalysts such as ZnO have disadvantages such as rapid electron-hole recombination rates and low photocatalytic efficiencies in aqueous media, which can be improved by a variety of methods. Is another photocatalyst. In this way, the photocatalytic property of the host semiconductor is significantly increased. In recent years, studies have been conducted on the positive effect of ZnO on the photocatalytic process, which include increasing the specific surface area, coupling ZnO with other semiconductors, correcting ZnO with metals and non-metals, reducing particle size, and sensitizing zinc oxide. Due to the importance of dye removal from wastewater of various industries such as textiles, in this study, the efficiency of the photocatalytic process of perovskites with ABO3 structure such as LaNiO3 has been investigated. LaNiO3 perovskite has good photocatalytic properties and is one of the semiconductors with limited band gap that is activated when exposed to visible light, the synthesis of which is also investigated in this study.  

در اين مطالعه كاتاليست نيكل-آهن بر پايه آلومينا در ريفرمينگ خشك متان در ميكرو راكتورها به منظور بررسي نحوه عملكرد كاتاليست و دستييابي به نقطه بهينه كاتاليست انجام گرفته است. 

   در اين پروژه اثر پيش پليمريزاسيون بر روي هموپليمريزاسيون اتيلن با كاتاليزور زيگلر-ناتاي صنعتي      TiCl4/MgCl2 مورد مطالعه قرار گرفت، وثوابت سينتيكي هموپليمريزاسيون اتيلن در شرايط مختلف      پيش پليمريزاسيون (دما، مقدار اتيلن ، فشار هيدروژن و نسبت Al/Ti ) محاسبه شد ، كه مشخص شد ثواب    سينتيكي شروع واكنش (Ka)، انتشار(kp) و غيرفعال شدن(kd) به شرايط پيش پليمريزاسيون بستگي    دارد. در حقيقت نشان داده شد با انجام پيش پليمريزاسيون مي توان رفتار كاتاليزوردر همو پليمريزاسيون    اتيلن تحت كنترل داشت. و با انجام پيش پليمريزاسيون به خواص پليمر و مورفولوژي مورد نظر رسيد و    شرايط را بهبود بخشيد. در اين پروژه اثر پيش پليمريزاسيون بر روي هموپليمريزاسيون اتيلن با كاتاليزور زيگلر-ناتاي صنعتي      TiCl4/MgCl2 مورد مطالعه قرار گرفت، وثوابت سينتيكي هموپليمريزاسيون اتيلن در شرايط مختلف      پيش پليمريزاسيون (دما، مقدار اتيلن ، فشار هيدروژن و نسبت Al/Ti ) محاسبه شد ، كه مشخص شد ثواب    سينتيكي شروع واكنش (Ka)، انتشار(kp) و غيرفعال شدن(kd) به شرايط پيش پليمريزاسيون بستگي    دارد. در حقيقت نشان داده شد با انجام پيش پليمريزاسيون مي توان رفتار كاتاليزوردر همو پليمريزاسيون    اتيلن تحت كنترل داشت. و با انجام پيش پليمريزاسيون به خواص پليمر و مورفولوژي مورد نظر رسيد و    شرايط را بهبود بخشيد.

Analysis of wire drawing process with free deformation zone

  In this study, the catalyst of Mn-Na2WO4/H-ZSM-5 with the percentage of 2% and 5% for Mn and Na2WO4 used as co catalyst in the process of oxidation coupling of methane fabricated. Selectivity, methane conversion and yield process were analyzed in several temperatures. The H_ZSM5 using as support, fabricated using hydrothermal method. The SEM, TGA and EDX were used to analyze catalyst properties. The results of experiments show that the selectivity was improved by 53%, the methane conversion reached 51% and the yield process of C2 reached 27% at 800 C.

  AbstractDuring the rolling process, the thickness of the metal sheet decreases through the space between the two rolls. Depending on the geometric and physical conditions, this process is categorized in both symmetric and asymmetric rolling. In the asymmetric rolling process, rolls radiuses, their environmental velocity, or frictional conditions between the upper and lower roll of the metal sheet may not be the same. The most important advantage of this process is that of symmetrical mode, reducing torque and reducing the force between rolls, and the most important adverse effect that may occur in this process is the curvature exiting and bending of the sheet when leaving the deformation region. In this thesis, the process of asymmetric cold rolling metal sheet has been studied analytically and numerically. In the analysis, the upper bound method is used. The rigid plastic material has been assumed and the contact arches of the rolls by a sheet have been replaced with a chord like them. The deformation area is divided into three regions and by providing a velocity field for each region, Shear, friction, internal deformation and total power are calculated. The effect of asymmetric factors such as the   roll radius ratio, the different angular velocities of the rolls, the non-uniformity of the friction conditions of the sheet with the upper and lower rolls on the total power and torque, the rolls separating force, and the radius of curvature of the output sheet have been investigated. Numerical analysis of the asymmetric cold rolling process has been done with the help of Deform software, which is very efficient in the field of forming. In order to optimize the process, in the software environment, a program has been written that minimizing the total power of the process and after implementation of the optimal parameters of the process in this process, which is optimized for these optimal solutions, the amount of rolling power is minimized. In the end, the results of the analysis were compared with the analytical and experimental results of other researchers, and the results of the simulation of finite element as well as experimental results. Comparisons of this analysis with experimental values indicate that the analysis carried out in this thesis, in most cases, predict the problems better than those of other researchers. Finally, with the confidence of the present method, the role of the above mentioned parameters is investigated with the aid of upper bound analysis and the effect of angular velocity, rolls radius, and upper and lower rolls friction factor, the percentage reduction of thickness and initial thickness of the input sheet are investigated.Keywords: Asymmetric rolling, upper bound analysis, plain strain.

Solar water splitting in the absence of sacrificial agent has been identified as a promising approach to produce green hydrogen. In this work, for the first time we report the photocatalytic activity of BiFeO3/g-C3N4 composite in hydrogen production. For this purpose we synthesized various BiFeO3/g-C3N4 composite samples with different mass ratio of g-C3N4 and investigated the as-prepared photocatalysts activity for hydrogen production during the overall water splitting reaction.The composite samples exhibits remarkably enhanced photocatalytic performance in comparison with the bare BiFeO3 and g-C3N4. The highest hydrogen production rate obtained is ? 160.75 µmol. h-1. g-1 under UV irradiation ( ? ? 250 nm) and ?23.31   µmol/h-1 g-1 under visible light irradiation ( ? ? 400 nm). This enhanced photocatalytic activity of BiFeO3/g-C3N4 heterojunction should be attributed to the synergistic effect of junction and the complementary advantages between BiFeO3 and g-C3N4, which can efficiently accelerate the separation of photogenerated electron-hole pairs and also capability to perform water reduction and oxidation reaction simultaneously.  

  Today, nanotechnology research is underway at a fast pace, and day by day various applications of this technology in various areas of life are made clear to humans. In the case of nanofibres, this is the case, and is used as one of the most important nanotechnology products in many areas. Nano fibers have attracted particular attention in recent decades due to their mechanical, physical and chemical properties, such as the high surface area, the bond between the fibers, the microfacial space between the fibers, and high porosity. Among the many available techniques for the preparation of nanofibres, the electrospinning method is a simple and efficient method that, with precise control of the operating conditions and the characteristics of the polymer solution, results in the production of more uniform nanostructures. In this study, the application of polyacrylonitrile / Schiff base alumoxane nanofibers was tested by electrospining and applied to experimental studies of the effects of conductivity properties and the removal of heavy metals from aqueous solutions using polyacrylonitrile / Schiff base alumoxane nanofibers. First, the Schiff base alumoxane and 2-mercaptoacetic acid alumoxane were synthesized first, and Schiff base alumoxane nanoparticles were investigated in a nanofibre structure to remove heavy metals from aqueous solutions using Design expert7 software. The polyacrylonitrile/Schiff base alumoxane nanocomposites were highly efficient in removing 97% of lead and 94% cadmium ions from aqueous solutions. To test the conductivity of nanofibres, 2-mercaptoacetic acid alumoxane nanoparticles have also been used with palladium nanoparticles in nanofibers with copper electrolytes and silver electroplating. Based on the results, the highest conductivity of 316.45(s/m) is about 2.5% of the 2-mercapto-acetic acid alumoxane nanoparticle and 0.03% of palladium.  

  هدف از انجام اين پژوهش بررسي رفتار استاتيكي و ديناميكي يك استوانه‏ پيزوالكتريك تحت بارگذاري‏ها و شرايط مرزي متنوع مي‏باشد. كه فرض شده است خواص اين استوانه با استفاده از قانون تواني توزيع مواد به صورت تدريجي و پيوسته هم در راستاي شعاعي و هم در راستاي محوري تغيير مي‏كند. پيزوالكتريك‏هاي PZT-4، PZT-8، PZT-5A و PZT-5H به عنوان پايه‏هاي تشكيل دهنده اين استوانه در نظر گرفته شده‏اند. منظور از تحليل رفتار استاتيكي بررسي كمانش سازه تحت بار حرارتي مي‏باشد و منظور از تحليل رفتار ديناميكي بدست آوردن فركانس‏هاي طبيعي و مود شيپ‏ها تحت ارتعاشات آزاد و بدست آوردن ميدان جابجايي و الكتريكي استوانه تحت ارتعاشات اجباري مي‏باشد. در اين پژوهش براي استخراج معادلات ديناميكي حاكم بر ارتعاشات استوانه از اصل هميلتون و براي حل معادلات و بدست آوردن ميدان جابجايي و پتانسيل الكتريكي از تركيب روش تحليلي و روش المان محدود طيفي استفاده شده است. بدين صورت است كه براي تغييرات در راستاي   از بسط فوريه به عنوان يك روش تحليلي و براي تغييرات در راستاي   و   از روش المان محدود طيفي به عنوان يك روش عددي استفاده شده است. اين روش امكان تحليل سه‏بعدي سازه را فراهم كرده است. علاوه بر اين با وجود بزرگ نبودن تغيير شكل‏ها، براي ديدن اثرات حرارتي در ماتريس سختي از تئوري الاستيسيته سه بعدي غيرخطي براي بيان رابطه بين كرنش و ميدان جابجايي استفاده شده است. و براي حل معادلات ديفرانسيلي مربوط به ارتعاشات اجباري نيز از روش نيومارك استفاده شده است كه در مساله ارتعاشات اجباري، دمپينگ رايلي براي سازه در نظر گرفته شده است. در نهايت نيز در هر مرحله تاثير پارامترهاي مختلفي مانند ضخامت استوانه، شاخص‏هاي قانون تواني مواد، بار حرارتي و انواع مختلف شرايط مرزي بر رفتار ارتعاشاتي سازه بررسي شده است. نتايج بدست آمده نشان مي‏دهند كه با افزايش شاخص‏هاي قانون تواني فركانس‏هاي طبيعي سازه افزايش مي‏يابد و با افزايش ضخامت سازه نيز سختي سازه و فركانس‏هاي طبيعي آن بيشتر مي‏شود. بيشتر شدن سختي سازه موجب افزايش دمپينگ رايلي مي‏گردد و بيشتر شدن دمپينگ رايلي نيز باعث كوچكتر شدن زمان نوسانات مي‏شود. از طرف متغير بودن خواص در طول سازه، موجب مي‏شود كه منحني‏هاي جابجايي و پتانسيل الكتريكي ديگر به شكل متقارن نباشند. علاوه براين نتايج نشان مي‏دهند كه اگر بارگذاري از حالت متقارن خارج شود، مودهاي پادمتقارن نيز در سازه به وجود خواهند آمد و حتي ممكن است كه سازه دچار پيچخوردگي شود و تاب بردارد. نمودارهاي مربوط به اثر بار حرارتي نيز نشان مي‏دهند كه با افزايش دما سازه، فركانس‏هاي طبيعي آن كاهش مي‏يابند.

شبيه سازي فرآيند نورد نامتقارن ورق هاي فلزي به روش اجزائ محدود

     In this study, MoO3 metal oxide was loaded by mechanical and wet impregnation methods on nano structure g-C3N and SBA-15 supports, respectively. After finding the optimum amounts of metal oxide loading, 10%MoO3/g-C3N4 and 5%MoO3/SBA-15 nano catalysts were used in the oxidative desulfurization (ODS) process. For investigation the performance of the synthesized nano catalysts in the ODS process, Dibenzothiophene (DBT), H2O2, and acetonitrile were selected respectively   as the target compound in 1000ppm model oil, oxidant, and solvent. In order to optimize the operating conditions including temperature, amount of catalyst, H2O2/DBT molar ratio and time reaction, Response surface methodology based on Box-Behnken Design of Expert (DOE) software was applied for each nano catalyst. Among the various models, DOE proposed the Quadratic equation model because of good accordance with experimental data for each catalysts (R-Squared=0.9831%, Adj R-Squared=0.9707 for 5%MoO3/SBA-15 and R-Squared=0.9569%, Adj R-Squared=0.9240 for 10%MoO3/g-C3N4, respectively). The results of optimization for 5%MoO3/SBA-15 nano catalyst were T=55 ?C, 0.02g amount of catalyst, H2O2/DBT=9 and 49 min reaction time and for 10%MoO3/g-C3N4 nano catalyst optimum condition were T=70 ?C, 0.04g amount of catalyst, H2O2/DBT=8.44 within 55min reaction time. The efficiency of the 5% MoO3/SBA-15 and 10% MoO3/g-C3N4 nano catalysts were predicted to be 100% and 97.7% in optimal operating conditions, respectively.     To evaluate the performance of the synthesized nano catalysts in the removal of other sulfur compounds in the optimal conditions expressed by DOE, two other model oils, 1000ppm Benzothiophene (BT) and Thiophene (Th), were applied in the ODS process, and the   removal efficiency of sulfur compounds was in order of   DBT > BT > Th. Also, the regeneration of the nano catalysts was evaluated four times, showing yield decreases of 5% and 6% for 5%MoO3/SBA-15 and 10% MoO3/g-C3N4, respectively. Finally, the performance of the   ano catalysts in the removal of sulfur compounds of gasoline and gas oil from the Kermanshah Oil Refining & Distribution Company was investigated, and the obtained efficiencies of sulfur removal were 69.73% and 49% for 5%MoO3/SBA-15   and 58.35% and 41% for 10%MoO3/g-C3N4 respectively.

<  gt;شبيه سازي كامپيوتري ديوار ترومپ براي گرمايش ساختمان مسكوني</P>

  The photocatalytic CO2 reduction has attracted more attention owing to the increasing global energy crisis and environmental contamination. In this work, BaTiO3 nanoparticles decorated with Fe2O3 nanoparticles were successfully prepared by hydrothermal method for efficient visible-light photocatalytic CO2 reduction, and successfully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), FT-IR spectroscopy, UV-visible and photoluminescence spectroscopy (PL) techniques. UV-visible and PL analyses showed the higher response of composites, in visible region and higher efficiency of charge separation, respectively. The FESEM illustrated the well crystalline particles of BaTiO3 and Fe2O3, and the BF31 (BaTiO3:Fe2O3 with 3:1 molar ratio) image shows a good dispersal of BaTiO3 and Fe2O3. Compared to bare BaTiO3, Fe2O3 and other different molar ratio composites, the BF31 composite photocatalysts exhibited strongest enhanced photocatalytic CO2 reduction activity under visible light irradiation. The photodegradation percentage of CO2 for BF31 composite could reach 22%, which was much higher than those of bare BaTiO3, Fe2O3 and other different molar ratio composite samples. The enhanced photocatalytic CO2 reduction activity could be attributed to the formation of heterojunction at the interface between BaTiO3 and Fe2O3 in the composite, which would facilitate the photo-generated electron-hole separation and thus improve the photocatalytic activity.

Recently, in the oil and refining industry, due to improving product quality and the decrease of environmental pollution, purification of fossil fuels from sulfur compounds is very important. Therefor, in this study we investigated performance of ZSM-5 supported molybdenum oxide catalyst in oxidative desulfurization. The main purpose of this research is study of support structure, molybdenum loading and operating conditions. we synthesized   ZSM-5 by two different methods, direct and seed silicate-1 by varying the Si/Al molar ratio at a constant Mo concentration of 3wt%.   The catalysts were characterized by XRD, N2-physisorption, FT-IR, FESEM. Our results indicated that   3% molybdenum oxide  upported  on ZSM-5 with Si/Al molar ratio of 15 and 20 compared to other catalysts are very active in oxidative desulfurization .The conversion percentage of these catalysts are nearly%80.Then,we investigated a series of zeolite supported molybdenum  oxide catalysts with Mo loading ranging from 3 to 15 wt% and Si/Al molar ratio of 15,20. Among Synthesized catalysts 6% molybdenum oxide  upported  on ZSM-5(15) and 10% molybdenum oxide  upported  on ZSM-5(20) have a high performance. eventually, 6% molybdenum oxide  upported  on ZSM-5(15) was investigated by Box-Behnken design. The Box-Behnken design showed that the optimum values for the conversion of DBT were 67?C (oxidation temperature), 0/04g (catalystamount),8 (O/S molar ratio) and 41/78 (Reaction time)   respectively. In addition, the catalyst shows excellent reusing ability. The results shawed slight decrease in performance of catalyst after four times regeneration.   

چكيدهدر اين پايان نامه از يك كاتاليست ناهمگن بازي برايتوليد بيوديزل استفاده شد و بهينه سازي صورت گرفت.براي تهيه كاتاليست   از   بوهميت به عنوان پايه استفاده شد و 10 فلز مختلف( كلسيم، منيزيم، روي، منگنز،كبالت،باريم،نيكل، استرانسيم، لانتانيوم، سريم) رويپايه قرارگرفت.10 كاتاليست سنتز شده تحت شرايط يكسان(6درصد وزني كاتاليست، نسبتمولي متانول به روغن 15:1، دماي 65 درجه سلسيوس و زمان 8 ساعت) تست شدند.از ميانآنها CaO/AlOOH داراي بالاترين بازده بود.براي بهينه كردن بازدهبيوديزل از روش سطح پاسخ با باكس بنكن استفاده شد.شرايط بهينه به دست آمده درواكنش تبادل استري شامل 75/3 درصد وزني كاتاليست،نسبت مولي متانول به روغن 33/8،102 دقيقه زمان انجام واكنش و دماي واكنش c°65   مي باشد.بازدهبيوديزل تحت شرايط بهينه % 2/99   به دستآمد.اين كاتاليست 4 بار قابليت بازيابي دارد و  بازده بيوديزل با كاتاليست بازيابي شده، بيشتر از 75 درصد است.واژه هاي كليدي :بيوديزل، تبادلاستري، بهينه سازي،كاتاليست ناهمگن بازي     

abstractRolling is a process in which one or more metal sheets are inserted into the space between two rollers and are affected by the thickness of the roller bearings. Among the methods used to analyze the shaping processes, the upper bound is analytical and well-considered. This dissertation deals with the upper boundary analysis with respect to the free zone of deformation and simulation of finite parts of rolling process. It is assumed that this process is performed under strain strain conditions. By analyzing the upper process boundary, the torque and the force of the rollers are calculated. For this purpose, firstly, the velocity field is obtained for different distortion regions. The internal power, shear power and frictional power are then calculated with respect to the effect of the hardness of the material, and calculated using the upper boundary method of the applied torque. At the end, the results of the analysis are compared with the results of testing other articles and the results of finite element. In the first step, the regions of the deformation are specified, then the velocity field in the deformation region is determined. After that, the field of strain rate and finally calculate the power, the total power is calculated. Friction power is also calculated at friction boundaries. In the frictionless boundaries where deformation has begun, shear power is available. After collecting all calculated power, the total power will be calculated. In the rolling process, the angular velocity of the roller is constant; by dividing the term calculated on the angular velocity, the torque required to start the process will be calculated. After calculating the torque, the force applied to the roller is calculated. The effect of friction on the results obtained and its comparison with the finite element components and its effect on the neutral point, including analyzes. It should be noted that the neutral point is the point at which the linear velocity of the roller is equal to the speed of the rolling sheet. The sheet is lowered to the deformation region at a speed less than the linear velocity of the roller and is extracted at a faster rate. At a particular point, the metal sheet adheres to the roller and its speed equals.The rolling process that is analyzed in this dissertation is rolling single-layer sheet. In this analysis, the results are compared with the experimental values ??of the previous investigators who have a good accuracy.The finite element analysis is performed by Abacus software and can be extracted after simulating the process, torque and force of the roller and speed, as well as other required results. This software is able to plot the charts of all parameters over time.In the end, it should be noted that the upper bound   and finite element analysis methods have a good accuracy for analyzing metal forming problems and can be used in industrial applications to design power supply transformers. Key words: rolling, upper bound, finite element

  AbstractIn this study, it was investigated the use of nano-silica heterogeneous catalyst in biodiesel production from canola oil. This catalyst was synthesized from wheat bran during acidic processing under controlled conditions. Wheat bran is an agriculture by-product which its burning is accompanied by environmental pollutants. This by-product contains high much amorph silica. Acidic processing of wheat bran and then thermal treating under controlled conditions in 700 C caused to nano-silica production with high area and with amorph structure. Nano-silica had high amount acidic sites. XRD analysis approved the synthesized nano-silica structure. The results for SEM showed that particles had spherical structure, regular and homogenous. The effects of four parameters including reaction temperature, catalyst concentration, molar ratio of methanol/oil and reaction time on biodiesel conversion was evaluated by response surface method. Molar ratio of methanol/oil was 99.01% under optimum conditions including 70 C, 3% catalyst weight and for 5 hours. The data for catalyst recovery showed that the prepared catalyst has renewability for 5 times which can be used as sustainable and economical catalyst for biodiesel production. Key words: wheat bran, nanosilica, biodiesel, canola oil, RSM optimization       

High-value chemical production using nanostructure catalysts

In this study titania-supported tungsten catalyst for oxidative desulfurization of model oil containing dibenzothiophene, using hydrogen peroxide as an oxidant and acetonitrile as a solvent extraction, over 90 min was investigated. Response surface methodology based on Box–Behnken design was used to evaluate the main operating parameters, including temperature, Amount of catalyst, oxygen to sulfur molar ratio, extraction phase to oil phase ratio. The optimum operating conditions had been attained at temperature of 80C, 0.04gr of catalyst, oxygen to sulfur molar ratio of 12.4, extraction phase to oil phase ratio of 0.68, respectively with the highest conversion of 97%.

Biodiesel is a clean and renewable energy, that using as a substitute for diesel fuel is growing worldwide. In this study, safflower seed as a convenient and cheap raw material for the direct production of biodiesel using contraction processes of extraction and transesterification in the presence of lime was chosen as a natural catalyst. For this purpose on a stage in process conditions similar to extract the maximum amount of oil from safflower seeds at different temperatures and times were investigated. Then, again given the choice of a suitable solvent, time and temperature optimum, biodiesel production was carried out with the catalyst of lime. In order to select a suitable solvent, at first the extraction by solvents such as methanol, hexane and acetone were evaluated and the results showed that the mixture of methanol - hexane (volume ratio 2:1) was the highest extraction efficiency. Then, for investigation of simultaneous transesterification, lime was used as a natural and economical catalyst for the transesterification process synthesis. During the experiment, the volume of solvent 300 ml and 60gr safflower seeds comminuted with 1.6% moisture selected also process time 8 hours and constant temperature 65°C and agitation 750 rpm was considered.