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.

  Given the global energy crises and the importance

With the growth of urbanization and the increasing demand for cooling in high-rise buildings, energy consumption associated with cooling systems has become one of the major challenges in the building sector. Studies indicate that the use of mechanical cooling equipment accounts for a significant share of energy consumption and greenhouse gas emissions, a trend expected to accelerate by 2050. Therefore, adopting innovative strategies to reduce cooling loads—particularly the integration of passive cooling systems—appears to be a sustainable and cost-effective approach. Numerous studies have investigated passive cooling systems, including the enhancement of traditional systems and their integration with phase change materials (PCMs). In recent decades, PCMs have been recognized as one of the effective elements in building cooling. Beyond their direct application in architectural and structural components (such as walls), PCMs have demonstrated remarkable performance when combined with passive cooling systems. In this thesis, with a focus on residential and non-residential high-rise buildings, a passive cooling–based approach was designed and presented, aiming to reduce energy consumption while maintaining indoor thermal comfort. However, challenges such as excessive weight, occupation of usable building space, and the possibility of independent cooling for individual spaces are also critical, yet often overlooked in previous studies. Based on the literature review, the following research questions were formulated: 1.   How can the integration of passive cooling systems with phase change materials and forced airflow ensure thermal comfort for occupants in high-rise buildings? 2.   To what extent does the proposed system contribute to reducing cooling load and maintaining indoor comfort conditions? The research method was experimental, relying on field testing. In the first stage, following a review of previous studies and identification of knowledge gaps, a passive cooling system was designed and constructed with the objectives of reducing energy use, weight, and space occupation compared to conventional systems, while enabling independent thermal comfort control in each space. The experimental tests were conducted at the Faculty of Arts and Architecture, Razi University, Kermanshah. A controlled office room was considered as the outdoor environment, and a test chamber was built as the indoor space. The cooling system prototype, measuring 55 × 21.80 × 95 cm and weighing 19.45 kg (lighter than comparable systems), was installed inside the test chamber (122 × 106 × 170 cm). To evaluate the system’s performance, three experimental scenarios were tested on consecutive days. The first scenario (07/04/1404) employed an organic Bio-PCM with a melting point of 22–23 °C. The second and third scenarios (08/04/1404 and 09/04/1404) used mixtures of 60% organic Bio-PCM + 40% coconut oil (melting point 20–21 °C), and pure liquid paraffin (melting point 20 °C), respectively. The PCMs were embedded in 15 copper tubes, each 50 cm long. Data were recorded at one-hour intervals between 9:00 a.m. and 3:00 p.m. using a hot-wire anemometer, a dual-channel data logger, and temperature-humidity sensors.

  در سال‌هاي اخير، تغيير الگوي زندگي شهري و افزايش تراكم در بافت‌هاي مسكوني، منجر به كاهش حضور فضاهاي باز و نيمه‌باز در آپارتمان‌ها شده است. در حالي‌كه در معماري سنتي ايران، فضاهاي نيمه‌باز همچون ايوان، حياط و رواق، نقشي اساسي در شكل‌دهي به كيفيت زيست، تعاملات اجتماعي و آسايش حرارتي ايفا مي‌كردند، در معماري معاصر اين نقش به‌تدريج كمرنگ شده است. پژوهش حاضر با هدف بررسي نقش تناسبات، نحوه‌ي دسترسي و همجواري فضاهاي داخلي در ميزان استفاده از فضاي نيمه‌باز در آپارتمان‌هاي مسكوني شهر خرم‌آباد انجام گرفته است.زندگي در ميان ساختمان¬هاي بلند نه تنها نياز به فضاهاي باز و نيمه¬باز را كم نكرده¬است، بلكه به علت كم شدن ارتباط انسان با طبيعت و محيط بيرون، بايد مورد توجه بيشتري قرار¬بگيرد. يكي از راه¬هاي انعطاف¬پذير كردن يك فضا، چند¬عملكردي بودن آن است. هدف از انجام اين پايان¬نامه طراحي آپارتمان مسكوني با تاكيد بر فضاي نيمه¬باز انعطاف¬پذير است، به گونه¬اي كه، استفاده كاربران از آن فضا افزايش يابد. پرسش اصلي مطرح شده اين است كه آيا قرارگيري تراس در جوار دو فضاي آشپزخانه و پذيرايي به صورت همزمان استفاده از آن را افزايش مي دهد؟ چگونه؟ اين تحقيق از نظر هدف، كاربردي و از نظر روش، تركيبي از تحليل محتواي كيفي با رويكرد همبستگي است. در مرحله‌ي نخست، مطالعات نظري و كتابخانه‌اي با هدف شناسايي مباني مفهومي و شاخص‌هاي مؤثر بر طراحي فضاهاي نيمه‌باز انجام شد. سپس در مرحله‌ي دوم، با استفاده از مصاحبه‌هاي هدفمند و پرسشنامه‌ي بسته، داده‌هاي ميداني از ساكنان محله‌ي كوي گلستان شهرستان خرم‌آباد گردآوري گرديد. جامعه‌ي آماري شامل ???? نفر از ساكنان اين محله بود كه بر اساس فرمول كوكران، حجم نمونه ??? نفر تعيين شد. داده‌هاي گردآوري‌شده با روش تحليل محتواي كيفي بررسي، كدگذاري و دسته‌بندي شدند تا عوامل مؤثر در نحوه‌ي استفاده‌ي كاربران از فضاهاي نيمه‌باز شناسايي گردد. يافته‌ها نشان دادند كه سه عامل اصلي شامل تناسبات تراس، نحوه‌ي دسترسي و نوع فضاهاي همجوار بيشترين تأثير را بر ميزان استفاده و رضايت ساكنان از فضاي نيمه‌باز دارند. تحليل پاسخ‌هاي پرسشنامه آشكار ساخت كه دسترسي مستقيم از آشپزخانه و پذيرايي به تراس، موجب افزايش دفعات استفاده، بهبود تهويه طبيعي، تسهيل فعاليت‌هاي روزمره (مانند پخت‌وپز، خشك‌كردن لباس يا دورهمي خانوادگي) و تقويت تعاملات خانوادگي مي‌شود. همچنين شكل تراس‌هاي تركيبي (تركيب مربع و مستطيل) با درصد بالاتري از آرا به‌عنوان تناسب مطلوب فضايي شناخته شد، زيرا امكان تفكيك عملكردي و در عين حال استفاده‌ي چندمنظوره از فضا را فراهم مي‌سازد. نتايج تحليل‌ها بيانگر آن است كه طراحي هوشمندانه‌ي فضاهاي نيمه‌باز، به‌ويژه در مجاورت فضاهاي پركاربردي همچون آشپزخانه و نشيمن، مي‌تواند كاركرد اين فضاها را از حالت تزئيني و غير‌فعال به عنصري پويا و مؤثر در كيفيت زيست آپارتمان تبديل كند. افزون بر آن، اين نتايج نشان مي‌دهد كه در بافت شهري خرم‌آباد، كاربران ترجيح مي‌دهند فضاي نيمه‌باز از نوع انعطاف‌پذير و قابل استفاده در تمام فصول سال باشد. داده-هاي حاصل از مطالعات و پژوهش¬هاي ميداني اين پايان¬نامه، پس از تحليل در طراحي آپارتمان مسكوني در شهرستان خرم¬آباد مورد استفاده قرار گرفته¬اند. از منظر كاربردي، يافته‌هاي تحقيق مي‌توانند مبنايي براي طراحي آپارتمان‌هاي مسكوني با فضاهاي نيمه‌باز انعطاف‌پذير در مناطق شهري مشابه فراهم كنند. نتايج اين پژوهش علاوه بر غني‌سازي مباني نظري طراحي فضاهاي نيمه‌باز در معماري معاصر ايران، راهنمايي عملي براي معماران و برنامه‌ريزان شهري محسوب مي‌شود تا بتوانند در قالب طرح‌هاي جديد يا بازآفريني بافت‌هاي موجود، كيفيت زندگي، تعاملات اجتماعي و آسايش محيطي ساكنان را ارتقا دهند. كليدواژه¬ها: طراحي، آپارتمان مسكوني، فضاي نيمه باز، انعطاف¬پذيري، خرم آباد

   اين رساله به بررسي نقش انرژي خورشيدي در كاهش مصرف انرژي ساختمان پرداخته است، در قدم اول اين پژوهش به بررسي روشنايي طبيعي ساختمان پرداخت شد و با اختصاص دادن 30 درصد بازشو به پوسته هاي خارجي بنا مقدار روشنايي طبيعي مطلوبي كه در حد استاندارد LEED باشد براي ساختمان تامين گرديد. در قدم بعدي عايق كاري جدارهاي خارجي انجام گرديد و مشخص شد استفاده از عايق هاي حرارتي مي توانند نياز ساختمان به انرژي را كاهش دهند در همين راستا پنجره هاي ساختمان نيز از حالت تك جداره به دو جداره تغيير كرد و با احداث دو مدل سايبان بر روي پنجره ها تلاش شد كه مصرف الكتريسيته كه جهت خنك سازي بنا استفاده مي شد با اين راهكار كاهش يابد. همچنين با استفاده از ديوار ترومب و ايجاد تهويه طبيعي در ساختمان مقداري ديگر از انرژي مصرفي در ساختمان كاهش يافت و در آخر با هوشمند سازي تجهيزات الكتريكي ساختمان، استفاده از تاسيسات سرمايي و گرمايي با راندامان بالا و جايگزين كردن آنها با سيستم ها با كارايي كمتر مقدار مصرف انرژي را كاهش داد. در نهايت با قرار دادن سلول‌هاي خورشيدي بر روي بام بخش زيادي از انرژي مورد نياز ساختمان تامين و مقدار توليد كربن دي‌اكسيد بنا نيز منفي شده است. در انتهاي رساله اعتبارسنجي طراحي پژوهش صورت گرفت و ساختمان طراحي شده با ساختمان واقعي كه هر دو در يك اقليم و شهر قرار داشتند مقايسه شدند و نتايج نشان داد كه با استفاده از راهكارهاي استفاده شده در اين پژوهش مي توان مصرف برق ساختمان را 3 درصد افزايش و مصرف گاز را 86 درصد كاهش داد. كاهش كلي ساختمان با استفاده از راهكارهايي گفته شده 75 درصد مي باشد. اين رساله به بررسي نقش انرژي خورشيدي در كاهش مصرف انرژي ساختمان پرداخته است، در قدم اول اين پژوهش به بررسي روشنايي طبيعي ساختمان پرداخت شد و با اختصاص دادن 30 درصد بازشو به پوسته هاي خارجي بنا مقدار روشنايي طبيعي مطلوبي كه در حد استاندارد LEED باشد براي ساختمان تامين گرديد. در قدم بعدي عايق كاري جدارهاي خارجي انجام گرديد و مشخص شد استفاده از عايق هاي حرارتي مي توانند نياز ساختمان به انرژي را كاهش دهند در همين راستا پنجره هاي ساختمان نيز از حالت تك جداره به دو جداره تغيير كرد و با احداث دو مدل سايبان بر روي پنجره ها تلاش شد كه مصرف الكتريسيته كه جهت خنك سازي بنا استفاده مي شد با اين راهكار كاهش يابد. همچنين با استفاده از ديوار ترومب و ايجاد تهويه طبيعي در ساختمان مقداري ديگر از انرژي مصرفي در ساختمان كاهش يافت و در آخر با هوشمند سازي تجهيزات الكتريكي ساختمان، استفاده از تاسيسات سرمايي و گرمايي با راندامان بالا و جايگزين كردن آنها با سيستم ها با كارايي كمتر مقدار مصرف انرژي را كاهش داد. در نهايت با قرار دادن سلول‌هاي خورشيدي بر روي بام بخش زيادي از انرژي مورد نياز ساختمان تامين و مقدار توليد كربن دي‌اكسيد بنا نيز منفي شده است. در انتهاي رساله اعتبارسنجي طراحي پژوهش صورت گرفت و ساختمان طراحي شده با ساختمان واقعي كه هر دو در يك اقليم و شهر قرار داشتند مقايسه شدند و نتايج نشان داد كه با استفاده از راهكارهاي استفاده شده در اين پژوهش مي توان مصرف برق ساختمان را 3 درصد افزايش و مصرف گاز را 86 درصد كاهش داد. كاهش كلي ساختمان با استفاده از راهكارهايي گفته شده 75 درصد مي باشد.

Abstract    This thesis examines the performance of double-skin façade systems equipped with phase change materials (PCM) and thermal absorbers in enhancing natural ventilation and reducing internal temperature fluctuations. The primary objective of this research is to analyze the impact of using PCM and thermal absorbers on increasing the thermal efficiency of the system, improving the chimney effect, and optimizing the internal temperature of the building.    To this end, three experimental scenarios were designed and executed over consecutive days: - Day One: Double-skin façade system without PCM and thermal absorber. - Day Two: System equipped with PCM. - Day Three: System equipped with PCM and thermal absorber.    The data collected on airflow, airspeed, the temperatures of the upper and lower vents, and internal temperature indicated that the use of PCM and thermal absorbers had a significant impact on improving the system's performance. The airflow and airspeed on Day Three reached their optimum levels, with the temperature difference between the upper and lower vents reaching its highest point, indicating an increase in the chimney effect and natural ventilation. Additionally, internal temperature fluctuations were minimized, resulting in a more stable internal temperature.    Analysis of the numerical values showed that on Day Two, airflow and airspeed increased by 25% and 20%, respectively, compared to Day One, and on Day Three, these values further increased by 15% and 10% compared to Day Two. Furthermore, the temperatures of the upper and lower vents on Day Two increased by 30% and 25%, respectively, compared to Day One, and on Day Three, these values were further elevated by 12% and 10%.    The results of this research indicate that the combination of phase change materials and thermal absorbers can be an effective solution for enhancing the performance of double-skin façade systems and reducing energy consumption. It is recommended that this technology be utilized in future designs across various climates, and intelligent control systems be implemented to optimize performance.    Keywords: double-skin façade, phase change materials (PCM), thermal absorber, natural ventilation, chimney effect, internal temperature optimization.   

Lithium-ion batteries have a high energy density, but heat production due to electrochemical reactions and the internal resistance of the batteries increases their temperature. Battery thermal management system plays an important role in maintaining the performance of lithium-ion batteries. Phase change materials (PCM) are widely used in battery thermal management systems due to their low energy consumption, high temperature uniformity, and affordable price, but the low thermal conductivity of PCMs has made their use a challenge. One of the ways to increase the thermal conductivity of PCMs is to insert carbon-based materials such as carbon nanotubes and graphene in PCMs. Due to their high thermal conductivity, these materials lead to strengthening the heat transfer of PCMs.Carbon quantum dots are one of the carbon-based materials that are in the nano-size range and have features such as high surface area to volume, excellent electrochemical activity and the ability to precisely adjust the electrical structure. Therefore, in the present study, a heat management system based on PCM reinforced with carbon quantum dots was presented. The phase change agent consisting of beeswax and coconut oil with different weight ratios was prepared and their physicochemical properties were investigated. Carbon quantum dots were also synthesized by hydrothermal and heating methods using citric acid carbon source and their physicochemical properties were investigated using different methods. Physical and chemical characterization of carbon quantum dots was performed using infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques.Then, the effect of PCMs reinforced with quantum dot carbon on lowering the battery temperature was investigated. The results showed that the addition of quantum dot carbon to PCM leads to a decrease in temperature in the optimal range of battery performance (less than 40 ?C)  

Theenergy-related crises in the global community have gained attention in recentyears, and over these years, numerous studies in various scientific fields haveproposed solutions to address these crises. The building sector, alongside theindustry and tra  ortation sectors, is among the largest energy consumers,particularly of fossil fuels and electricity. After residential spaces, schoolsare the second environment where people spend a significant portion of theirlives. This thesis aims to examine the energy consumption of a six-classroomschool in the city of Kermanshah, using an active solar system. The researchmethod employed in this thesis is descriptive-analytical, and for this purpose,computer modeling tools have been utilized.In the first step, the currentenergy consumption status, physical facilities, and energy needs of the schoolwere assessed. The school building is designed as a two-story structure, withthe physical program and activity schedule considered based on standards. Bysimulating the energy structure of the school, the annual energy consumption,including heating, cooling, and electricity needs of the building, wascalculated. In the next step, five changes were applied to the buildingenvelope, and the energy demand variations in response to each parameter changecompared to the initial state were simulated and analyzed.In the final step,the impact of adding an active solar system on the building's energyconsumption was calculated. The final simulation results showed that the optimaluse of insulation in walls and roofs, the optimal type of window glazing, thedimensions of shading devices, and the reduction of the window-to-wall arearatio significantly reduced the building's annual energy consumption whencompared to the initial simulation state using all optimization tools.Thecomparison between the initial and final simulation results highlighted thatoptimization had the greatest impact on the building's heating demand. On theother hand, the use of these optimization tools slightly increased thebuilding's cooling demand, primarily due to changes in the thermal propertiesof the building envelope. Additionally, the optimization tools led to anincrease in the net annual electricity demand, mainly due to the reliance on electricityfor meeting the building's cooling needs. The active solar system contributedto approximately 22.79% of the annual electricity demand, but the system doesnot achieve a return on investment over a ten-year period.

در بسياري از صنايع مهندسي ذرات جامدي كه همراه سيالات حمل مي¬شوند، توانايي آسيب سايش به خطوط لوله و خصوصاً اتصالات را دارند و آن¬ها را در معرض نشت و شكست قرار مي¬دهند. در واقع سايش يك مكانيسم مكانيكي است كه سبب جداشدن مواد از سطح به دليل برخورد مكرر ذرات جامد است و خسارت¬هاي مالي و جاني در پي دارد. به همين سبب باعث شده است كه اين موضوع اهميت پيدا كند و روش¬هايي در جهت كنترل سايش پيشنهاد شود. يك روش مناسب براي پيش¬بيني نرخ سايش حل ديناميك سيالات محاسباتي است كه در سال 1990 امكان استفاده از اين روش فراهم شد. پژوهش حاضر سعي در استفاده از رويكرد اويلر - لاگرانژ با نرم‌افزار انسيس فلوئنت دارد بدين منظور كه شبيه‌سازي جريان سيال (فاز پيوسته) در ديدگاه اويلري و شبيه‌سازي رديابي ذرات جامد (فاز گسسته) در ديدگاه لاگرانژي صورت مي¬گيرند. در ادامه فرايند استقلال از شبكه و ذرات براي جريان دوفازي گاز - جامد در هندسه زانويي 90 درجه استاندارد انجام مي¬شود. همچنين اعتبارسنجي داده¬هاي عددي حاضر مساله با داده¬هاي تجربي ديگر مقالات تحت شرايط يكسان، براي جريان تك¬فاز و دوفاز مقايسه مي¬گردند تا نتايج قابل‌قبولي لحاظ گردد. در همين راستا سبب شد مدل آشفتگي از نوع تنش رينولدز، كوپل يك¬طرفه، مدل سايش اوكا، مدل ضريب بازگشت ذرات گرانت و تاباكف و نيروهاي وارده بر ذرات شامل پسا، جرم مجازي، شناوري و گرانش در حل عددي اين پايان‌نامه انتخاب شوند. پارامترهاي زيادي در ميزان سايش دخيل هستند كه در اين پژوهش برخي پارامترها شامل سرعت جريان، اندازه قطر ذرات، نرخ ورودي ذرات و تأثير زبري سطح ديواره مورد بررسي عددي قرار داده شدند. در بين اتصالات، زانويي¬ها در معرض خطر جدي¬تري هستند. با پيشنهاد جايگزيني اتصالات ديگر كه هدف و ماهيتي شبيه به كارايي زانويي دارند، انتخاب مي¬شوند و سايش را نسبت به زانويي 90 درجه استاندارد كاهش مي¬دهند. اتصالات شامل دو نوع خم مايتر، سه نوع اتصال كور، زانويي كاهنده و دو نوع زانويي كروي شكل هستند. شرايط حل عددي براي تمام اتصالات جهت مقايسه نتايج با يكديگر به¬صورت مشابه تنظيم مي¬گردند. سپس نتايج عددي نهايي پايان‌نامه بيان مي¬كند كه در سرعت جريان و قطر ذرات يكسان براي بحراني‌ترين حالت، اتصالات ذكر شده مقاومت سايشي را 22/5% تا 39/6% نسبت به زانويي 90 درجه استاندارد افزايش مي¬دهند.

Cooling of electronic equipment is a fundamental challenge in the electronics industry, so the development of new electronic systems depends on solving this challenge. In a Core I7 processor, more than 731 million transistors are accumulated in an area of 270 square millimeters, and their design thermal power reaches 140 watts. Removing this thermal load requires new methods. In recent years, the use of phase change materials in these systems has shown that these materials are effective in improving the thermal performance of heat sinks. Due to the increasing use of these materials, it is necessary to examine their thermal behavior in different conditions and to study the conditions where the presence of these materials leads to the improvement of the performance of heat sinks. These conditions depend on the geometry and materials of the heat sink components as well as its functional conditions. In this thesis, the thermal efficiency of a thermal heat sink equipped with a phase change material is investigated. The type of phase change material and its mass fraction in the presence of vanes and the arrangement of vanes are among the parameters that are studied. In addition, the efficiency of the heat sink may change over time depending on the amount and type of PCM, and therefore it is necessary to study this parameter over time. The results of this study can determine the conditions in which the presence of PCM leads to the improvement of the efficiency of the heat sink and introduce the appropriate limit for the use of PCMs. Also, in this study, it has been investigated that the presence of the valley in which wall of the heat sink has improved the performance of the heat sink in terms of cooling.  

Abstract Due to population growth and the industrialization of today's societies, the global demand for energy is continuously increasing. Fossil fuel sources, including crude oil, coal, and natural gas, are among the most important sources of energy in Iran. In this regard, the extraction of natural resources and the excessive consumption of fossil fuels not only lead to the depletion of these natural gifts, but also cause irreparable impacts to the environment such as the destruction of the ozone layer, air pollution, and global warming. do In such a way that human environmental effects have caused the earth to warm by 2 degrees Fahrenheit as a result of the heating related to carbon dioxide caused by the burning of fossil fuels and natural gases. Since the industry sector has a significant contribution to the country's final energy consumption, reducing energy consumption in this sector is an effective step towards optimizing energy consumption and reducing greenhouse gas emissions and environmental pollution, because the world Today, it is facing an energy crisis and very dangerous environmental challenges. Therefore, this thesis aims to design a building model for industrial poultry farms in Hersin city so that it can reduce the amount of energy consumption in these units by using appropriate solutions. In this regard, by using a field research field, receiving information in the form of a library, reading books, theses, and receiving scientific and research articles via the internet, it has been compiled and studied. Therefore, using the obtained information, an industrial unit with the use of meat poultry has been designed and simulated by computer and DesignBuilder software. Based on this, by applying energy consumption optimization solutions and the results obtained from it, the energy consumption compared to the simulated building has been investigated and compared, so that the optimized building has been able to The rate of electricity consumption and the rate of gas consumption have been reduced. Keywords: energy, poultry farming, environmental pollution, industrial architecture  

   Abstract The increase in population and the advancement of technology in the 20th century has accelerated the process of industrialization in countries. This increase required a lot of energy supply, and for this reason, industrial societies have increasingly used fossil fuels. Indiscriminate use of this type of fuel has led to destructive environmental effects and extensive changes in weather and climate worldwide. The concentration of greenhouse gases such as carbon dioxide, methane and other greenhouse gases is increasing due to human activities. This issue has raised concerns about the increase in the earth's temperature. According to research, it is likely that the Earth's temperature will increase by 1 to 5 degrees Celsius during the current century, which is a trend in the global average temperature that is outside the natural variation of temperature changes in the last thousand years. In this thesis, a theoretical research has been conducted in which simulation has been used and through that, the required information has been obtained through library resources, climate data, weather information and so on, Collected. This information has been simulated by computer using Designbuilder and Polysun software, and using the obtained results, a low-energy industrial unit (zero energy) has been designed in the textile industry. This building has been able to meet its energy needs using renewable energy. And it has also had zero annual results in energy consumption and production. The results obtained from the simulations showed that after applying energy consumption optimization strategies, the building consumption in the areas of cooling, heating, lighting, hot water consumption and equipment used for a full year, decreased by 61.35 percent compared to the reference building and has reached 68.45 KWh/m2. Also, by the solar system installed on the roof of the building, this system has been able to produce 76.70 KWh/m2 of electrical energy. According to the results, the difference between the amount of energy consumed and the amount of energy produced showed that in addition to confirming the achievement of a zero energy building, the solar system produced 8.25 KWh/m2 in excess of the energy requirement. Keywords: Architectural Design of Industrial Units, Textile Industry, Zero Energy, Kermanshah

Today, buildings consume 40% of the world's energy, which will increase with population growth in the future. Due to the technological development in recent decades, various and efficient tools have been invented to simulate the thermal behavior, energy consumption in relation to the heating and cooling load and to check the lighting of buildings in the planning and design stages. The use of these tools includes shortcomings such as: the presence of too many parameters and inputs as software regulator inputs; The time-consuming nature of each simulation is due to the extensive basic physics calculations and the effectiveness of the user experience on the accuracy of the output. The aim of this thesis is to present a new method to evaluate and compare the effect of different shades on the illumination of the interior spaces of buildings using the pix2pix model from the subsets of the adversarial generative network algorithm. The research method in this simulation-analytical proposal was through the use of image input information as a dataset and the production of corresponding output information indicating the lighting conditions of the interior of the building in different scenarios. The dataset used in this thesis was generated through data simulated by Rhino, Grass Hopper, Ladybug Tools and TT Toolbox software, and Python language was used for dataset preprocessing, model development and evaluation. The efficiency of the proposed method in relation to the reduction of simulation time, the accuracy of the simulations carried out using the trained model and the reduction of the regulator inputs of the proposed tool were investigated in comparison with the existing methods, including the simulation method by basic physics software such as Radiance. The results stated that in the evaluation of the speed of the model, 281.94 times increase in speed compared to the radiance has been achieved. Radiance is obtained. The result of this thesis was to create a developed and trained model to predict the effect of different shades on the amount of daylight. The obtained model is the innovation of this thesis, which can use higher speed, acceptable accuracy, and fewer parameters in daylight forecasting than basic physics software.   

Abstract: Due to the limitations of mineral resources on the earth and the distant horizon for long-term life on this planet, preservation and maintenance of materials against damage and destruction becomes very important in industrial societies. On the other hand, the growing process of industrialization of human life has increased the share of industrial sectors in the financial portfolio of governments, and governments are forced to send a large amount of their financial resources to the industrial market every year in order to reach the desired level of industry. Abrasion is one of the main destructive events in the fluid transfer sector in industries. Especially when two-phase and multi-phase fluid flows are involved. Obviously, the countries where the transfer of refinery, power plant, oil and gas fluids is considered their vital artery are more involved in this phenomenon in their industries than others. Today, software simulations compete strongly with laboratory research. Because laboratory research, despite all its inherent advantages and advantages, has disadvantages such as high costs. On the other hand, the increasing power of computer systems for analysis and simulation is a powerful support. This research is a simulation with the help of numerical methods, in which a 90 degree elbow is considered as a sample piece (which is one of the most damaged industrial connections). To carry out the desired simulation, a computational fluid dynamic model has been used along with the discrete cell method. The continuous fluid and the particles injected into the flow at the elbow inlet were simulated in different geometries. The final simulation model includes McLaury's Erosion model based on the validation results. Particles are tracked by Lagrangian method along with random collisions of Grant-Tabakoff recursive model. To ensure the correctness of this choice, another validation has been used in this section. Considering that particle momentum plays an important role in Erosion, in this research, it has been tried to make the injected particles lose their momentum by rotating the water flow lines. Therefore, changes were made in the same direction in the knee geometry. The result of this research shows that changing the geometry of the elbow reduces the momentum of the particles when they collide with the internal surfaces to the extent that it increases the life of the elbow by about 8 times in the case of using internal spiral blades. Key word: Erosion, elbow, helical blades, computational fluid dynamics, Euler Lagrange, particle tracking   

   As one of the most basic urban infrastructures, water distribution networks are very important for human society, especially in Iran, and considering the water supply in the country in the past few years, it needs to design basic networks. Economy is needed in the country. Therefore, the improvement of water distribution networks is not a step towards the management of water resources and also the basic design of water distribution networks. So that the optimization takes into account economic limitations and water resources and maintenance of the network, etc. Since one of the important factors in the control and management of the network is the application of optimal pressure in the network, and it is also another factor for planning the economic plan or reducing the costs of construction and maintenance of water networks, in this thesis, locating the optimal position of pressure relief valves in the network as a supplier The goal has been to reduce the costs in the network, and the pressure is another goal, taking into account the provision of the desired pressure. Also, the NSDE multi-objective algorithm is used as an optimization model in this research, and the commercial and free EPANET software is used for the hydraulic simulation of the water distribution network. A case study in this research is for Khorramshahr water distribution network. In this research, it has been shown that after the implementation of the model, the results obtained in the improved model are completely superior to the current state, that is, the state without valve breaker. So that for one pressure relief valve, the pressure is 8.616% and for 2 pressure relief valves, this amount of pressure reduction is equal to 39.64%. 39.642% pressure reduction in three pressure relief valves in Khorramshahr water distribution network, 39.839% pressure reduction in 4 pressure relief valves, 55.262% pressure reduction in the network and for 6 and 7 pressure valves a pressure reduction equivalent to 55.287 and 55.456 It was very useful and practical to consider the scenario of firefighting in the network to evaluate the target. On the other hand, it can be said that adjusting the pressure relief valve in accordance with the positions and output options of the proposed models is a significant improvement in the issues, i.e. the pressure is in the desired range and the costs are reduced.

  Given the high seismicity of many regions in Iran,

The rapid economic growth in the world has led to anincrease in energy consumption during the last decades. According to recentstudies, the energy consumption of cooling and heating systems in buildings isabout 60%. As a result, any development in thermal system technology to lessenenergy consumption, especially in buildings, is welcomed. Phase changematerials (PCM) with high density for energy storage are one of the mosteffective ways to reduce energy consumption in buildings. In this thesis, usingDesign Builder version 7 software, heat transfer of a 4x4x3 electrical facilityroom located in Tehran city is simulated. Throughout these simulations, thethermal behavior of wall equipped with PCM layers has been examined. The various parametersof wall and PCM considered in the simulations include the thickness,conductivity coefficient, melting temperature of PCM material, and also heatgeneration within the room. The results showed that by increasing the thicknessof PCM, the amount of daily thermal load of the building decreases and as aresult, the thermal performance of the room is improved. By changing thethickness of PCM from 5 to 10 cm, the thermal performance coefficient of PCMincreases by 20-25% depending on the melting temperature of PCM. It is foundthat there is an effective thickness for PCM, after which increasing thethickness has a negligible effect on reducing the thermal load. As anotherresult, it was found that the conductivity coefficient has a small effect on thethermal performance coefficient so that for all the studied cases, the effectof conductivity changes in the range of 0.2 to 2 W/m2 °C on the thermalperformance coefficient is less than 13%. Also, the results showed that anincrease in the internal production of heat, leads to a decrease in the valueof the thermal performance coefficient, and in this case, the phase changematerial has a poor performance.  

  In this research, the effect ofroughness on thermal creep flow in microchannels has been investigated. Forthis purpose, a planar microchannel is considered in which a linear temperaturegradient is applied on the walls. In order for the wall temperature gradient tobe the only factor for creating the flow, the pressure at the inlet and outletof the microchannel is assumed to be the same. The dimensions of the channelare 0.2 x 1.2 µm, and different linear temperature gradients are applied to itswall. The flow is in the range of 0.002 ? Kn ? 0.2, that is, the slip flowregime. The governing equations, including continuity, Navier-Stokes and energyequations along with the velocity slip and temperature jump boundaryconditions, have been solved in the COMSOL Multiphysics software environment.Roughness is modeled using W-M fractal function, which is a completely randommodel. The effect of various fractal roughness parameters on thermal creep flowhas been investigated in detail, including relative roughness, 0 ? ? ? 4,fractal dimension, 2 < D < 1, and roughness density 1 ? Rd ? 5. Theresults show that the mass flow rate in rough microchannels is lower than thesmooth ones; And this decrease is more noticeable in higher Knudsen numbers.Therefore, in small Knudsen numbers and close to the continuum flow regime, theroughness effect is less important. For example, a high relative roughness of4% in near continuum flow with Kn = 0.002, leads to 15% decrease in mass flowrate; While the relative roughness as small as 0.5% in the Knudsen number of0.2 causes the mass flow rate to decrease by more than 27% compared to thesmooth channel. In general, it was observed that in different conditions, themass flow rate increases with the decrease of relative roughness, but there isa limit beyond which the flow behavior becomes independent of the roughnessheight, that is ? = 1%. So that, in the relative roughness of less than 1%, theflow is independent of the roughness parameters and the mass flow rate remainsalmost constant. In addition, it was found that the increase in roughnessdensity strongly reduces the mass flow rate, so that at high densities (Rd =5), the effect of thermal creep flow almost disappears. These last two featuresare specific to thermal creep flow and are not seen in pressure-driven andshear-driven flows.

Controlling the heat generated by electronicequipment and microelectromechanical systems at high capacities is importantfor optimal performance and greater reliability. Open microchannel heat sinksare a new geometry of microchannels heat sinks that are important due to theirlower manufacturing cost and better heat transfer performance. In this research, heat transferand fluid flow characteristics of open microchannel heat sink in 17 differentgeometries, which includes 3 main shape of rectangular fins, plano convex fins andplano concave fins, that variable fins base heights varied from 0.4-0.7 mm, andin 2 shape of plano convex fins and plano concave fins on the same variablecurve range coefficients 0.20-0.5 for plano convex fins shape and 0.35-08 Forplano concave fins shape   on an equal finsbase height which the convective surface area and the materials that arerequired to build a heat sink are equal have been investigated. Openmicrochannel heat sink cooled by water fluid in   a laminar flow and single phase flow   that Reynolds number varied from 100-600 andheat flux 100-600 kWm2   that numericallyand in a three-dimensional geometry analyzed by Ansys Fluent software. At thesame heat flux, Reynolds number and fins base height, the Nusselt number of therectangular fins shape is less than the two shapes of plano convex fins andplano concave fins.in Comparison of two shapes of plano convexfins and plano concave fins in the lower fins height, the Nusselt number of theplano concave is more than plano plano convex and in the higher fins height,the Nusselt number of the plano convex is more than the plano concave. Despite the fact that at high heightsin the fins, where the Nusselt number of the plano convex fins shape is greaterthan the rectangular and plano concave   shape,but the plano convex pressure drop is less than these two shaps. The results show that at the end of the path, where theheat sink temperature is higher, in the plano concave model due to the moreconvective surface area at the end of the path has a lower critical temperatureand temperature non-uniformity. Despite the higher Nusselt number in plano convex finsshape in the curve coefficient of 0.80, 0.65 and 0.50 Compared to other plano concavefins shape in curve range coefficients of 0.35 and0.20, have a lower pressure drop than the above shapes.  

Abstract In recent years, microfluidic technology has been considered by many researchers in various fields of biology, chemistry and medical engineering due to its many advantages such as reducing the sample size, producing less waste, saving time and money. One of the main parts of laboratory processes is cell isolation. In laboratories, different methods are used to isolate or count cells; One of the main disadvantages of these methods is the high volume of the prototype, and the process of testing by these methods requires a lot of time and money. The use of dielectric force has become one of the most popular manipulation methods in microsystems due to its favorable effects such as laboratory scale, simplicity of instrument, ability to induce positive and negative forces and, most importantly, ineffective particle structure. Today, with technologies such as on-chip laboratories and dimensional shrinkage (nano and micro), all of these experiments can be performed in less time, with greater accuracy, and with smaller sample sizes. With the development of on-chip laboratory technology, the tendency to use this technology for cell isolation for cell counting or diagnostic applications in micro-dimensions has increased. Since the electrophoresis force allows us to use laboratory technologies on the chip to count or separate, and has the ability to shrink in micro and nano dimensions, more attention has been paid. What is discussed in this dissertation is the effect of different electrode shapes, different frequencies, fluid properties, channel dimensions, electrode dimensions and electrode spacing in applying dielectric force in cell separation. Since the main purpose is to isolate biological cells and these cells are strongly dependent on temperature, after comparing electric fields, field gradient, fluid conductivity and dielectric force, the effect of changes in these elements on temperature should be investigated. The sensitivity of biological cells to temperature is such that if the temperature rises above a certain value, these cells will die. Then the effect of changes in voltage and fluid conductivity is investigated and finally its effect on the process of separation of living cells from non-living cells.

Choosing an optimal filteration system can reduce operating, repair and breakdown costs in many industries. If the suspended particles in the fluid are magnetic ones, magnetic filters can be used to separate them. Since internal magnetic filters are not able to separate FeS particles and other sub-micron particles, the use of high gradient magnetic filters is suggested as a solution. An important parameter in evaluation of these filters is the rate of adsorption of suspended particles in the liquid. Therefore, in this research, with the aim of COMSOL simulation software, the amount of particle adsorption and the effect of effective parameters on this parameter have been investigated. In both two-dimensional and three-dimensional simulations, a transverse configuration with a constant matrix diameter and a constant magnetic flux density is used. Important parameters of this research are the Reynolds number of the flow, the transverse distance of the rod matrices and the particle diameter. In three-dimensional analysis, according to the given variable parameters, the horizontal distance of the matrices and Reynolds number play an important role in the amount of particle adsorption, so that for horizontal distances greater than H = 1.4, the particle adsorption rate is significantly reduced, and the percentage Particle absorption is below 27%. It was observed that changing the particle diameter has less effect on the particle adsorption rate. The highest particle adsorption in the fluid occurs with the magnetic field strength of 1 Tesla with a rectangular arrangement for the horizontal distance H = 1.4 and the Reynolds number Re = 2, which has an adsorption rate of about 35%. The absorption rate of particles in the three-dimensional state is approximately one-half that of the absorption in the two-dimensional state. This can be explained due to the fact that all variables in two-dimensional and three-dimensional simulation were the same. Therefore, the same number of particles is considered in both geometries leading different values of adsorption.   

underground dam 

Abstract : Every year, human losses and irreparable economic catastrophes caused by earthquakes in different parts of the world are imposed on nations. Population growth and improved quality of life have led to an increase in the number of buildings and urban infrastructure, as well as an increase in public demand, which directly and indirectly increases the likelihood of various damages due to major earthquakes. In the meantime, the excavations located in the city and the effects of their existence on other adjacent structures are not ineffective in increasing the probability of various damages. The aim of this study was to investigate the two-dimensional combination of topographic effects and soil characteristics on the seismic response of excavations and adjacent structures. For this purpose, 48 hollow models with different geometric conditions of rectangular and trapezoidal shape located on the bedrock as well as a layer of sediments with 4 different impedance ratios were evaluated. The geometry of the rectangular pits was considered in 5 aspect ratios and the trapezoidal pits were considered in 5 different angles. It should be noted that parametric studies have been performed using two softwares. First, hybrid software is used to evaluate the seismic response of the structure by combining the finite element method in the near field and the boundary component method in the distant field Then, using Abacus software, the accuracy of the results is checked. In each of the excavation models, first the critical points were determined under the influence of the various factors mentioned and then the behavior of these points were analyzed and evaluated more and more comprehensively. Finally, practical diagrams for engineering uses are presented so that the spectral response of the pits can be estimated in a simple way Also, in order to improve seismic regulations in order to reduce the damage caused in the known conditions, the results can be used to complete seismic geotechnical studies.   

در اين مطالعه عددي، اثر شكل نانوذرات بر روي عملكرد حرارتي-هيدروليكي نانوسيال آب-آلومينا در هيت سينك داراي ريز مجراها با هندسه­هاي مختلف براي خنك كاري پردازشگرهاي الكترونيكي مورد مطالعه قرار گرفته است. اين مطالعه، براي پنج شكل نانوذره پلاكتي، تيغه­اي، مكعب مربع، بيضوي و استوانه­اي در چهار عدد رينولدز 400، 800، 1200 و 1600 در چاه گرمايي داراي ريزمجرا­ها با چهار مقطع دايروي، مثلثي، بيضوي و شش ضلعي انجام شده است. غلظت نانوسيال ثابت و مقدار آن برابر با 1% در نظر گرفته شده است. در اين مطالعه مشاهده شد كه هيت سينك با مقطع مثلثي بيشترين ضريب انتقال حرارت جابجايي را ايجاد مي­كند، و پس از آن، هيت سينك با مقاطع بيضوي، شش ضلعي و دايروي به ترتيب موجب ضرايب انتقال حرارت بزرگ­تري مي­شوند. همچنين، نانوذرات با شكل پلاكتي بيشترين افت فشار را ايجاد مي­كنند، و پس از آن، نانوذرات با شكل­ها­ي استوانه­اي، تيغه­اي، مكعب مربع و بيضوي به ترتيب موجب افت شار بزرگ­تري مي­شوند. در نهايت با ارائه يك پاراكتر مناسب (FoM) كه معرف نسبت افزايش نرخ انتقال حرارت جابجايي به افزايش افت فشار است، ميزان بهره­وري انرژي مورد ارزيابي قرار گرفته است.   

  شبيه­سازي جريان­هاي چند فازي و مطالعه نشست ذرات

چكيده در مطالعه حاضر به بررسي عددي انتقال حرارت جابجايي طبيعي در حفره مربعيمتخلخل اشباع شده از نانوسيال آب اكسيد آلومينيوم پرداخته شده است. هندسه موردبررسي شامل يك حفره مربعي با دو دايره داخلي است . دماي دايره ­هاي داخلي ثابت،گرم و سرد مي­باشد. دماي ديواره هاي عمودي به صورت سينوسي تغيير مي­كند هاي افقي نيز عايق مي­باشند. نانوسيال به صورت تك فاز مدل سازي شده است. برايجريان سيال در محيط متخلخل نيز از مدل دارسي برينكمن فورچهيمر استفاده شده است. نتايجتحقيق شامل بررسي اثرات پارامترهاي عدد رايلي، عدد دارسي، درصد حجمي نانوذرات،عدد ناسلت ميانگين، عدد ناسلت محلي، پروفيل­هاي سرعت و دماي بي بعد و خطوط جريانفاصله بين مركزهاي دايره­هاي داخلي، و استفاده از نانوذرات مختلف و همچنين اختلاف فاز ديواره­ها بر رويجابحايي طبيعي   خطوط جريان و دماي بي بعد به سمت نيمه بالايي ديواره سرد و نيمه پاييني ديواره گرم متمايل مي­شود.مي­باشد. نتايج نشان داد افزايش عدد رايلي و دارسي سبب بهبود انتقال حرارت جابجايي و به تبع آن باعثافزايش عدد ناسلت و سرعت جريان در محفظه مي­شود. با افزايش عدد رايلي و بهبود افزايش كسر حجمي نانوذرات باعث افزايش لزجت نانوسيالو كاهش سرعت نانوسيال در محفظه مي­شود و افزايش نيروي شناوري مي­شود. افزايكسر حجمي نانوذرات در اعداد رايلي و دارسي تاثيرات متفاوتي بر روي عدد ناسلتميانگين دارد در اعداد رايلي كوچك و دارسي بالا افزايش كسر حجمي نانوذرات سببافزايش عدد ناسلت مي­شود اما با افزايش عدد رايلي از تاثير افزايش كسر حجمي نانوذرات كاسته شده و در برخي از اعداد رايلي و دارسي مختلف تاثير متفاوتي بر انتقال حرارت و عدد ناسلت دارد.افزايشو دارسي سبب كاهش عدد ناسلت مي­شود. افزايش فاصله بين دايره­هاي داخلي در اعداداختلاف فاز ديواره سرد سبب افزايش عدد ناسلت ديواره گرم مي­شود. از بين نانوذراتاستفاده شده نانوذرات مس به دليل داشت هدايت حرارتي بيشتر، عملكرد بهتري در بهبودانتقال حرارت دارند  

  In the polymer modified concrete, polymer is added to the concrete as the main component to enhance adhesion, ductility and durability. The joint performance of 3D polymer film in conjunction with the materials produced by cement hydration, improves some concrete properties. In this research, experimental studies to investigate the effect of three polymer of methyl methacrylate (MMA), pure acrylic (PA) and styrene butadiene rubber (SBR) with 3, 5, 8 and 10 percent cement replacement on polymer modified concrete containing 5% micro silica was made. The reduction of compressive and tensile strength causes the use of micro silica. To investigate the physical and mechanical properties of concrete, the specimens were tested to slump tests, air ratio of fresh concrete, compressive strength, tensile strength and water absorption.   Also, by drawing stress-strain diagram of all specimens, energy absorption capacity, modulus of elasticity, strain and ductility coefficient were also investigated. The results showed that by adding these three polymer to the concrete, in all specimens, reduced the compressive strength, tensile strength, water absorption, elasticity modulus. The air ratio, the ratio of tensile strength to compressive, energy absorption capacity, strain and ductility coefficient increased. The slump values also increased with the addition of styrene butadiene rubber (SBR) and decreased with the addition of methyl methacrylate (MMA) and pure acrylic (PA).

Thermodynamic and Physical Properties Prediction of Natural Gas using AGA8 Standard- Gross Characterization Method and Modifying it with Artificial Intelligent-Based Techniques

  AbstractAdvances in Internet technologies have led to the popularity of technology-based self-services, with the design of such services becoming increasingly important. This thesis identified the key service attributes driving adoption and use of transactional e-government services, and citizens’ preference structures across these attributes by using technology-based services in the public sector. An unsolved quest still however is how to categorize such e-services. Stage-models are today dominating for pinpointing high-range  characteristics of e-services. The classification of the services helps in understanding their importance. As a conceptual category, one can distinguish between economic and information services. At the same time there is a flaw that there are no good models for categorizing services. Efforts have been made to use such models as the Classification Diamond for electronic services. Hence, the main purpose of this thesis is to introduce a new and easy-to-use and well-form model for the classification of e-government services. In this thesis, a review was initially carried out on the most popular models of e-government services categorization. In the research that took place, the ESI model has a more coherent structure for classifying e-government services. In contrast, the rhombus model is a graphical model that has a well-formed character. Then, a classification model was first introduced for the Iraqi government services using the ESI model. This model is then upgraded in the form of a Diamond model. So, in the rhombus model, classification information is filled in from the table ESI. Presence, Non-Presence, Government performative, Citizen informative, and Financial and Non- Financial. Within each of these categories sub categories such as separate vs. compound, and individual vs. general is used for the purpose of make an even more fine-grained classification.  

  Drug delivery within the human body has a significant role in the treatment of many diseases. There are different methods for tra  orting a pharmaceutical compound to a specified part of the body among which magnetic drug targeting is of great attention.   A magnetic drug delivery system utilizes the magnetic field to tra  ort the magnetic nanoparticles as a means of a delivery vehicle. Therefore, it is possible to control the delivery of the drug in such a way that the particles of the drug to be focused adequately where necessary. This will accelerate the recovery of the disease and also prevent the destruction of healthy tissues by the drug. Cardiovascular diseases are one of the major causes of deaths of women and men in recent years which have different types. One of the most common cardiac diseases is abdominal aortic aneurysm. In this disorder, due to the weakening of the vessel wall and blood pressure, the aortic vessel in the abdominal region expands and may lead to tearing of the vessel. Usually, treatment of this disorder is aggressive and has a high risk. But an alternative approach based on embolization of aneurysm, brought up recently seems to be a cure for this disease. In this method, aneurysm region will be targeted by particles of demanded drug, using an external magnetic field. So the pressure on targeted vessel wall will reduce. In this thesis, the three-dimensional transient flow of blood and transfer of drug are simulated with Eulerian-Lagrangian approach in the region of abdominal aorta vessel suffering from an aneurysm. According to the physics of the problem, the oscillating velocity at the inlet with non-Newtonian fluid are considered for the blood flow and the effect of aneurysm geometry, magnetic field and specifications of drug particle are studied. The results indicate that an increase in the size of an aneurysm, vertical distance between aortic vessel and magnetic source and Reynolds number leads to a decrease in the efficiency of drug absorption. At the other hand increasing the strength of magnetic field, size of particles and magnetization of nanoparticles leads to increase in the capture efficiency. These findings can be used to design and develop the drug targeting systems for the human body.Keywords: Magnetic drug targeting, abdominal aortic aneurysm, magnetic nanoparticles, Eulerian-Lagrangian approach, non-newtonian fluid

  This thesis examines the numerical and experimental performance of a metal foam heat sink in the free convection heat transfer. Metal foams are porcelain materials that used recently in the wide range application. This welcome is due to the appropriate thermo physical properties such as high volume ratio and high thermal conductivity. They are very lightweight because of their high porosity (0.9 and further).   The specimen used in this experiment is an aluminum foam (13 mm × 40 mm × 40 mm) of 92% porosity with 10 ppi. The experiments were carried out for heat sink inclination position of 0 °, 30 °, 60 °, 90 ° and 4, 8, 12, 16 watt power input. Numerical simulation was performed by finite element method and commercial software Comsol Multiphysics5.2. The heat transfer and fluid flow in the metal foam is expressed in terms of the macro volume theory based on the local thermal non-equilibrium condition (LTNE) for the energy equation. In this work, effect of foam geometric parameters, foam height, heat sink inclination angle and base temperature on the thermal performance of metal foam was investigated. The experiments results, show that the thermal performance of heat sink with increasing input heat flux decreases. For power input of 16 watts, the highest Nusselt number belong the inclination of 60 degrees (25.75).Comparison of thermal performance between horizontal and vertical heat sink indicates that the performance of horizontal heat sink is better than the vertical. The results of the numerical model show that the highest mean Nusselt number for all foam samples are in the horizontal position. It can be concluded that the average Nusselt number decreases with increasing porosity, and increases with decreasing in pore density. Influence of metal foam pore density of on the Nusselt number shows that in the samples with a 10 ppi and ppi 20 do not differ greatly, but the specimen with ppi 5 has a better performance. Comparison of Nusselt number in vertical(25.29) and horizontal(30.94) heat sink with 0.92% porosity and 5 ppi show that the mean Nusselt number in the horizontal position is %22.34 more than the vertical position. Comparison of Nusselt number of a metal foam heat sink ( 0.92% porosity and 10 ppi) with a flat plate in the horizontal position at the same base temperature (97.7 ?) indicated that the Aluminum metal foam increasing Nusselt number by %62.59. mean Nusselt number in the horizontal upward position is %29.52 more than the horizontal downward position

  AbstractBitumen and asphalt self-healing is present as an intrinsic property in bitumen and asphalt, and asphalt and bituminous asphalt researchers seek to recognize, expand, and ultimately make practical use of this feature. Self-resiliency is different from thixotropy, and unlike thixotropy, it is related to the repair of crack cracks caused by the loading and it can be considered as a reversible fatigue phenomenon. Self-resurfacing depends on factors such as temperature, rest time, crack width and features of bitumen and asphalt, and is activated by temperature rises, so scientists are looking for the best and most economical way to create heat in asphalt, from The suggestion of these innovative methods can be found in the method of heating through electromagnetic waves and the heating method through microwave waves. Researchers have used various methods to assess the quality and quantity of self-defense, most notably fatigue-based tests, rupture tests, and non-destructive tests.In this dissertation, the ability to repair three types of modified asphalt with additives with a non-additive asphalt type (for comparison) was investigated through rupture-based experiments (three-point bending test), for which the semi-cylindrical samples The Marshall was repaired by a three-point bending device and then warmed up by microwave irradiation and after a 24-hour period. After repair, the samples were restored by three-point bending test to determine the degree of repair. On the other hand, the temperature created on the surface and in the asphalt samples was investigated and according to the results of the experiments, the asphalt made with two The additive of nanosecotherm and Fortah fibers has the highest initial resistance and secondary resistance to the other three types of asphalt, and the uniformity of temperature in this type of asphalt was more evident than other asphalt.

  در اكثر محاسبات مهندسي مكانيكبراي جريان­هاي در ابعاد معمول به­جاي تحليل پيچيده­ي اثرات واقعي ملكول­ها از يكفرض توزيع پيوسته ماده استفاده مي­شود و محاسبات جريان با اين فرض پيوستگي انجاممي­شود. اگرمتوسط مسير پويش آزاد ملكولي با كوچكترين طول مسأله هم­مرتبه باشد فرضپيوستگي ماده صادق نيست. براي تحليل اين جريان بايد از روش­هاي پايه­اي­تر مانندروش­هاي ملكولي استفاده كرد. در چندسال اخير با گسترش زمينه­هاي مكانيك سيالاتجريان در ابعاد ميكرو و نانو بيشتر مورد توجه محققين قرار گرفته است. جريان­هايگازي ميكرو و نانو به­واسطه­ي طول مشخصه كوچك­شان معمولا در محدوده­ي ناپيوستگيجريان قرار دارند. يكي از پركاربردترين روش­ها براي حل اين جريان­ها استفاده مي­شودروش ذره­مبناي شبيه­سازي مستقيم مونت­كارلو (DSMC) مي­باشد.اين روش در جريان­هاي با عدد نودسن بالا به­خوبي عمل مي­كند.اما مشكل اين روش در جريان­هاي كم­سرعت مشاهده مي­شود. نوسانات آماري موجود در روشDSMCمانع از شكل­گيري درست جريان در مواردي كه سرعت پايين است مي­شود. يكي از روش­هاييكه براي رفع اين مشكل ارائه شده است روش ذره­مبناي نگه­داري اطلاعات(IP) مي­باشد. در اين روش قوانين بقا (بقاي جرم، بقاي مومنتوم و بقايانرژي) مشابه تحليل­هاي ماكروسكوپي، در خصوص اطلاعات IPپياده مي­شود. در اين پايان­نامه اساس روش­ DSMC-IPبه­عنوان ابزار عددي و ذره­مبنا براي حل جريان­هاي گازي رقيق­شده ارائه شده است.كد DSMC2 توسعه داده شده و روش IP بهآن اضافه شده است. هندسه­ي مورد مطالعه ميكرومحفظه­ي مربعي با ديواره­ي متحرك مي­باشد.اين جريان به واسطه­ي گردابه­هاي موجود در آن جرياني پيچيده است.برهم­كنش بينملكولي با استفاده از مدل كره­ي سخت متغير مدل­سازي شده و همچنين از طرح برخورد SBT براي انتخاب جفت برخوردي استفاده شده است. جريان دما ثابت است وگاز تك اتمي آرگون به­عنوان سيال مدل­سازي شده است. نتايج به­دست آمده موفقيت روش IP را در رفع نوسانات چگالي، سرعت، تنش برشي و... را نشان مي­دهد.همچنين علاوه­بر رفع نوسانات موجود در جريان­هاي سرعت پايين، نوساناتي كه در جريان­هايبا نودسن كوچك ايجاد مي­شود را نيز برطرف مي­كند. روش IPعلاوه­بر رفع نوسانات، در كاهش هزينه­ي محاسباتي نيز بسيار مؤثر است. نتايج حاصلاز حل IP نشان مي­دهد كه موقعيت مركز گردابه­ي اصلي با افزايش سرعت ديوارهدر جهت حركت ديواره جابه­جا مي­شود و همچنين با كاهش عدد نودسن جريان مركز گردابهبه سمت بالا جابجا مي­شود.

Aerosols are very small solid particles or liquid droplets suspended in a gas phase. It is very important to study aerosols evolution and its relevant processes including coagulation, deposition, condensation, and source reinforcement. It seems even more essential in issues such as nuclear reactor containments contamination and its environmental effects. On the other hand, Analytical solution of the governing aerosol evolution equations is not possible except in some limited cases. In this research direct simulation Monte Carlo (DSMC) method is employed to develop a numerical computer code which simulates coagulation and deposition processes in multicomponent aerosols with different densities. The coagulation and deposition processes are simulated based on Brownian motions and diffusion of particles, respectively. The effects of gravity are considered for both processes as well. Sectional method, which is the common technique in simulation of aerosols evolution, is used to validate the ability of our DSMC code in modeling coagulation and deposition processes. The comparison results in a well agreement between two methods. Furthermore, the evolution of nuclear aerosol of Uranium dioxide enriched with water particles is investigated using the validated DSMC code. The Uranium dioxide particles, ranged from 0.01 to 0.04 micrometers in diameter, are distributed in a cubic repository of one meter edge length. Then water particles are added to the aerosol and the evolution of Uranium dioxide particles including mass distribution variations as well as deposition and coagulation of suspended particles are studied. The water particles, which have the same size in each study, are ranged from 0.012 to 0.551 micrometers in diameter. It is observed that increasing the water particles diameter results in decrease of uranium dioxide particles deposition; such that for water particles with mean diameter 0.55 micrometers, the uranium dioxide particles are mainly suspended. On the other hand, due to coagulation of small particles over the time, remaining suspended particles have much larger diameters (70 times greater than initial size in average). These features can be beneficial in many ways such as tra  orting and deposition controlling of aerosols as well as using larger hole filters (less flow restriction) in case of air purification of nuclear repositories. Finally, taking a closer look at the deposition process, an estimated relation is used to improve the simulation of the coagulation. We call this method modified deposition rate DSMC in contrast to common DSMC. This modification results in more realistic simulation with completely different results compared to common DSMC. Another disadvantage of the prevalent DSMC is using estimated deposition rates in modeling diffusional deposition which does not take advantage of the prominent feature of the DSMC method that is particle tracking. However, simulating diffusional deposition by means of estimated deposition rates fail to use the ability of DSMC method in particle tracking. Therefore, a new scheme for simulation of diffusional deposition is proposed which is based on movement and position of particles and hence more accurate. The results of this method are close to modified deposition rate DSMC.

New modern world intensively needs high quality and reliable electricity energy. Distributed Generation (DG) resources are one of the best choices for electricity energy provision. Whereas use of distributed generation resources provides feasibility of implementation of hierarchical control on small grids alike big grids, electrical energy distribution grids that comprising distributed generation resources are known as Microgrids. Microgrids usually are used in grid connected mode but if fault occurs in grid or when improvement of load power’s quality is need, they can work in islanded mode. Because of presence of 1 phase loads and 1 phase resources such as solar cells, microgrids’s voltage aren’t balanced. Voltage unbalancing causes decrease of electrical energy’s quality, increase of losses and decrease of microgrids’s stability. So proposition of suitable control solution for unbalancing voltage compensation is very important. In this thesis we want to compensate voltage unbalancing in Point of Common Coupling (PCC) in presence of 1 phase unbalanced load for both grid connected and islanded modes because voltage unbalancing might causes diturbtion and makes problems for sensitive loads. For voltage unbalancing compensation usually two decoupled control loop are used for positive and negative sequences. This structure is known as Double Synchronous Reference Frame (DSRF). In this thesis for improvement of current and voltage DSRF controller’s performance and elimination of oscillations in unbalanced voltage condition, Decoupled Double Synchronous Reference Frame (DDSRF) has used. The method is in such a way that oscillation’s amplitude and phase is estimated and implemented to DSRF. So oscillating couple between positive and negative current control loops and between positive and negative voltage control loops are eliminated and it causes of unbalancing voltage of PCC in both grid connected and islanded modes.

  Micro-grid is a small local network and consist of distributed generation resources and loads that is used to enhance the power quality and reliability for consumers in the functions that are connected or separated from the main network. Today, with the increase of small and big single-phase loads, the quality of the voltage in the Micro-grid is more importance than before. One of the common issues in analysis of voltage quality is unbalanced voltages. Unbalanced voltages has several factors, most of these factors occur due to unbalance loads. In this research, the voltage unbalanced factor and their effects on the micro-grid facilities is described. Then, in order to voltage unbalance intensity evaluation, various indices and standards of voltage unbalanced are considered. The proposed scheme in this thesis, describes the voltage balancing and analysis of inverter- based distributed generation systems. The control scheme used to compensate unbalanced voltage due to unbalanced load in three-wire three-phase micro-grid is an extraction of positive and negative components of both voltage and current using d-q axis for inverter-based voltage sources during the occurrence of unbalance in the micro-grid. This scheme is used to compensate unbalanced voltages in the point of common coupling. The purpose of this design is to control the positive and negative components of the voltage separately and generate reference currents. Because micro-grid are used in the grid-connected and island mode, so their controller method is considered in this two mode too. The control of output power of each of dispersed generation units in the both grid-connected and island mode is done with the Droop Control. At the end, in order to improve the performance of the controllers, the coefficients of these controllers are optimized so as to minimize the current error using the online Particle Swarm Optimization (PSO) algorithm. That one of the benefits online method is to resolve the uncertainty problem of system parameters. In order to verify the proper performance of the control system, a micro-grid with two voltage source converters (VSCs), unbalanced local load and network are simulated with the MATLAB/SIMULINK and grid-connected and island mode are investigated.

In this study, natural convection flow in a micro enclosure is investigated using direct simulation Monte Carlo (DSMC) method. Argon molecules are used for gaseous medium. The sidewalls of the enclosure are subjected to various boundary conditions including adiabatic, constant temperature and symmetry where symmetry boundary condition simulates the flow in a long channel. The aspect ratio of the enclosure is set to AS = 2. The lower wall is heated to temperature TH and the upper wall is cooled to TL while the thermal ratio is preset to rT = TH/TL= 0.1. Similar problem for macro-scale channels which is known as Rayleigh-Benard problem is widely investigate. However, the micro enclosure problem which classified as rarefied flow is still under study. The Knudsen number is assumed in the range 0.001 ? Kn ? 0.12 and a wide range of 0.2 ? Fr ? 10000 is studied for Froud number. The results show that the thermal creep effect has an important role in formation of convective rolls in the enclosure. Unlike the channel flow where no vortex will appear in adequate low or high Froud numbers (based on Knudsen number), in enclosures we have vortexes in all Froud numbers at all Knudsen numbers due to thermal creep phenomenon.   It is shown that the heat transfer rate is the same for channel and enclosure at very small or very high Froud number. However, for mediate Froud numbers heat transfer rate decreases in enclosure as where the side walls resist against convective rolls. The bounds for the values of high or low Froud number depend on the Knudsen number. Finally, the ability of SBT collision scheme in simulation of Rayleigh-Benard convective flow is evaluated in this study. Comparing to NTC scheme which is conventional collision scheme for DSMC method, it is shown the SBT scheme is accurate enough to simulate the Rayleigh-Benard instability flow.

In this work the thermal performance of a two-stage DX-SAHP for high temperature condensing in the rang of 60-100 °C with considering the effects of he pressure drop associated with the flow of R134a refrigerant through the condenser,collector/ evaporator and connection pipe is analyzed numerically.the Homogeneous method for two phas pressure drop inside horizontal pipes is used to calculate the two phase refrigerant pressure drop.This system employs a bare flat plate solar collector with a surface area of 5.5 m2 ,a hot water tank with the volume of 150 L,two rotary-type hermetic compressors,two thermostatic expansion valves and a flash chamber.The effect of various parameters, including solar radiation, ambient temperature, collector surface area, compressor speed,wind speed and number of collector cover has been studied on the thermal performance of the system.The results show that the hours of system operation, during different months in the climate of Kermanshah, vary between 44 to 144.4 hours and the monthly average COP and the solar collector efficiency vary between 4.4 to 7.66 and 55.1 to 79.63 percent respectively.also the thermal performance is compared for two-stage and single-stage DX-SAHP at the Kermanshah climate. the results show that the performance of two-stage DX-SAHP is better than that of single-stage system.monthly average COP and the solar collector efficiency for the two-stage DX-SAHP vary between 4.389 to 7.768 and 71.44 to 100.3 percent respectively and for single-stage vary between 3.92 to 6.05 and 66.25 to 96.12 percent respectively.also the hours of system operation, during different months for two-stage DX-SAHP is less than that of single-stage system

In recent years, studies on microelectromechanical systems have shown that there are considerable opportunities for microsensors based on mechanism like piezoelectric. Microelectromechanical systems objective in miniaturization, multiplicity, creation and integration of microelectronic systems. Today microelectromechanical systems have numerous application in vehicles, military industries, medicine, sensors and actuators. New technologies have led to increase in use of piezoelectric materials. One of the recent changes is using piezoelectric materials as sensors and microsensorS in microsystems. Piezoelectric are a category of smart materials which can be used in electric energy harvesting from environment. Using these materials as sensors has grown popular due to lack of need for an external source. These materials can be used frequently in strain gauges, active biomedical materials, switches, pressure and vibration sensors, accelerometers, flow detectors and vibration and ultrasonic controllers. In the present thesis, speed sensor design and manufacture using piezoelectric polymer and wind energy harvesting via these materials are studied. Piezoelectric polymer is used as cantilever beam inside the low-speed wind tunnel. Standard DC circuit is used to convert piezoelectric alternating voltage to direct voltage using an operational amplifier too boost the piezoelectric output voltage. By performing various tests on the sensor, the relationship between piezoelectric output voltage and wind speed was obtained. The result of sensor tests indicated this relationship can be approximated with a first degree function. The amount of harvested energy from wind is also tested in different speeds. Peak power and power density were obtained with speed of 15m/s and optimal resistance of 2200 as 7.38 mW and 134.2 mW/cm3 respectively. Finally, the produced voltage and harvested energy can be used for wireless sensor networks, sensors and also for place in which changing batteries are not possible.