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Shotcrete, a pneumatically sprayed concrete mixture, has gained significant popularity in the construction industry due to its versatility and adaptability. However, the demand for high-strength shotcrete has intensified, driven by advancements in equipment and admixtures. Fiber-reinforced high-strength shotcrete (FRHSS) offers enhanced quality, adhesion, and construction speed, making it ideal for stabilizing excavations and slopes, strengthening masonry and concrete structures, and reinforcing underground structures. Additionally, the increased strength allows for reduced section dimensions, leading to more economical designs.

This research investigates the effects of aggregate gradation and admixtures, including micro silica, superplasticizer, accelerator, and micro recycled steel fibers (MRSFs), on the strength and performance of FRHSS. The study employs wet-mix and dry-mix shotcrete methods, examining the properties through laboratory and field experiments.

The results demonstrate that achieving high-strength shotcrete is more feasible with the wet-mix method. Fiber-reinforced wet-mix shotcrete attained a 28-day compressive strength of 987 kg/cm², representing an 80% and 77% increase in compressive strength and energy absorption, respectively, compared to conventional fiber-reinforced wet-mix shotcrete. Furthermore, fracture toughness tests revealed that MRSFs effectively prevent microcrack propagation and control deformations. FRHSS incorporating MRSFs exhibited a 28% and 97% increase in compressive strength and energy absorption, respectively, compared to the corresponding mix without fibers.
 

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In order to facilitate the release of floods from the dams and to prevent their damage or collapse, a structure called a spillway is used. Due to the natural and variable flow of the input to the reservoirs of the dams, there are times when the river inflow exceeds the consumption amount in the downstream agricultural lands. In these cases, excess water is discharged over the crest of the weir and flows towards the spillway, which causes high velocities. This high velocity creates low pressure areas on the spillway concrete surface, which can cause major damage to the spillway or even endanger the integrity of the dam structure. Therefore, the dam spillway must safely dissipate the kinetic energy. One of the types of weirs is the stepped spillway to facilitate the passage of the flow over the dams. One of the most obvious practical features of stepped spillways compared to other spillways is the considerable energy dissipation along the spillway. Care should be taken in designing and selecting the type of spillway to prevent potential erosion and reduce kinetic energy as the water flow passes over the spillway. One possible solution is to use a stepped spillway instead of a smooth spillway. In this study, a numeral model of a stepped spillway with different steps and slopes is used. For this purpose, ANSYS software is used for modeling free surface with application of k-ε turbulence model. In the present study, numerical simulation using the Volume of Fluid (VOF) model was used to investigate the mixing phenomenon of two phases of air and water of the free surface flow. The flow field was continued until the residuals reached 10^-7. Compared to simpler models such as Mixture, which operates solely on the basis of averaging the properties of two phases, the VOF model, is separating the phases and considering the effects of the interface. The VOF model, is capable of more accurate simulation of phenomena such as fluid mixing, turbulent flows, and heat transfer in multiphase flows. A number of hydraulic specifications which are considered in designing the stepped spillways are the pressure on the surface of the steps, velocity distribution and energy dissipation. The results from the numerical models were compared with experimental studies. They showed acceptable agreement with physical simulations. Results show that discharge and spillway slope increment reduces the amount of energy loss. In the spillway with 5 steps, for a discharge of 0.063 m³/s, the amount of energy dissipation at a slope of 26.6 degrees changes from 85 to 82% at a slope of 45 degrees, which shows a decrease of 3%. With the increase in discharge, the flow depth increases and reduces the effect of the roughness of the steps on the upper layers of the flow. Increasing the height of the steps increases the rate of energy dissipation and also increases the occurrence of negative pressures in stepped spillway. In this case, the contact surface between the main flow and the eddy currents increases. With the increase in the height of the steps, the dimensions of the rotating vortices also increase and cause a larger radius of rotation on the steps. The presence of these large rotating vortices separates the flow from the bottom of the steps and reduces the pressure on the surfaces. The number and dimensions of steps can alter the energy dissipation rate. Increase in the number of steps in a spillway with constant height, reduces the energy loss as the result of steps dimensions being shrunk

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Steel plates are widely used in various industries, especially in civil engineering. Low cost in implementation and reduction of seismic mass are the advantage of steel shear wall system compared to other structural systems. The goal of a good design is that along with following the existing guidelines and achieving the desired seismic resistance of the structure, the structure is affordable in terms of weight and cost. Considering that according to the design, it is not possible to achieve the optimal use of the structure's capacity by force control method, the theory of uniform deformations was proposed with the assumption of a constant performance level. The subject of design based on performance increase the safety of the structure against earthquake force and design with optimal seismic performance during the useful life of the structure in seismic areas. Also, compared to the design method based on force control, it can lead to a lighter and economical design.
One of the significant ways to reduce the weight and stiffness of shear walls and boundary elements connected to them is to limit the connection of filler plates to boundary elements. In this method, limiting the length of the connection reduces the force on the beams and columns, and as a result, smaller sections can be used.
In this research, in order to achieve the optimal performance level, two concrete frames with steel shear wall resistant system are subjected to nonlinear analysis. Then, the initial evaluation of the behavior and the correctness of the used method are checked. After that, the effective factors in achieving uniform stress in the height of the structure will be investigated. For this purpose, by using the effect of the thickness parameter and the appropriate pattern of connection of the shear steel plate to the surrounding elements, the way of changing the performance and behavior of the structure will be investigated. For this purpose, 3- and 4-story concrete frames with steel shear wall systems were modeled using ABAQUS^TM finite element software. The steel used in the steel shear wall system is ST37. First, the connection of steel shear plates to floor beams was considered and then the influence of the partial connection pattern on the seismic performance of the steel shear wall system was investigated. The modeled frames were subjected to dynamic analysis, linear and nonlinear buckling analysis, and cyclic analysis. Based on the obtained results, the property of energy dissipation in the frame with a steel shear wall system with partial connection has increased significantly. Changing the partial connection pattern led to changing the maximum in-plan relative displacement. Also, the surface of the stress distribution shows that in the partial connection, the stress concentration mainly occurred in the place of the steel shear plate connections. In addition, according to the results of cyclic analysis, considering the partial connection of the steel shear wall has led to a decrease in the average energy absorbed in the structure and an increase in its ductility. Also, changing the connection pattern has affected the average amount of absorbed energy in different loading cycles.

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A numerical model for two-phase debris flows is developed in this paper, on the basis of understanding of the physical characteristics of debris flows from field investigations and experiments. Employing a moving coordinate, the kinetic energy equation of gravel particles in unit volume in debris flow is developed by considering the potential energy of the particles, energy from the liquid phase, energy consumption due to inner friction-collision between the particles, energy dispersion through collisions between particles, energy for inertia force, energy consumption due to the friction with the rough bed and energy consumption at the debris front. The model is compared with measured results of two-phase debris flow experiments and the calculated velocity profiles agree well with the measured profiles. The gravel’s velocity at the debris flow head is much smaller than that of particles in the following part and the velocity profile at the front of the debris flow wave is almost linear, but the profile in the main flow shows an inverse ‘s’ shape. This is because the gravel particles in the main flow accelerate as they receive energy from the gravitational energy and flowing liquid and decelerate as they transmit the energy to the debris flow head and consume energy due to collision with the channel bed.

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Nowadays, investigating and researching on energetic polymers in order to increase mechanical, thermodynamic, and detonational properties of them have been highly regarded. One of these energetic polymers is GAP. In this paper, molecular dynamics simulation has been used to compare the properties of GAP and GTP energetic polymers. GTP, in principle is the modified form of GAP, in which functional group of triazolium methyl nitrate has been added instead of azide. The mechanical properties of GAP is a challenging topic in the field of energetic materials. Due to the attributes of the 3 azoliom methyl nitrate ring, the mechanical and thermodynamic properties of GTP are expected to be higher than GAP. The results obtained by molecular dynamics simulation showed that GTP is a stable material and its mechanical properties such as Young, and shear modulus compared to GTP have been decreased 27% and 32% respectively, and bulk modulus, Poisson coefficient, and K/G ratio compared to GTPhave been increased 17%, 42%, and 71% respectively. It was also found that the detonation speed, detonation pressure, and oxygen balance of energetic polymer compared to GAP, have been increased 5%, 14%, and 21% respectively. As a result, usage of GTP will increase as a modified GAP material in applications such as clean and chlorine-free propellants for the solid propellant rockets and also safety systems of automobiles.

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Today, carbon dioxide emission is one of the concerns of all countries in the world, so in this paper, we examine the effect of export quality, energy efficiency, and economic complexity on CO2 emissions per capita during the period of 1990 to 2014 in emerging economies. For this purpose, first, energy efficiency is calculated using mathematical programming methods (DEA). Then, the effect of export quality, energy efficiency, and economic complexity on per capita carbon dioxide emissions in the panel of emerging economies is investigated using panel quantile regression. The energy efficiency results show that the average energy efficiency of the studied countries had been increasing from 1990 to 2014. The lowest efficiency score among the studied countries is related to China. The results of quantile regression indicate that the export quality and consumption per capita of fossil fuels have a positive and significant effect on CO2 emissions per capita in all quantiles. The results also show that the coefficient increases by moving in the level of quantiles, so that, the highest effect coefficient of export quality on CO2 emission is related to the quantile 90th and about 0.874. Energy efficiency has a negative and significant effect in all quantiles except 90th, and the highest coefficient of influence (0.133) is related to quantile 10th. The increase in economic complexity increases the co2 emissions in all quantiles except 10th, and the highest coefficient (about 0.487) is related to quantile 90th. 

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Asbads are a type of windmill with vertical axis which are considered as the oldest windmills in the world. These mills have been constructed in pre-Islamic eras in Sistan and southern part of Khorasan. From a long time ago, Sistan has been considered as the Iran’s store of wheat. Climate and appropriate soil along with the water of big Hirmand River have provided an appropriate situation for agricultural farms and particularly for wheat. As said, Sistan had been known as a wheat store of Iran. 120-day wind of Sistan is a natural feature of Sistan region. In this region, in the second half of warm season, when wheat is being harvested, vigorous winds start to blow. All of these characteristics provide the situation for constructing the Asbads which are considered as a great innovative production. In this regard there are different evidences which show that the oldest windmills are built at the east of Iran and in Sistan area. Main building of Asbad includes a two-storey building in which upper storey is usually open-ended. Moreover half of the building which is subjected to the wind is constructed completely open and the other half is completely enclosed. The part which is behind the wind side is also entirely open. Asbads have had an important role in past people’s livelihood and also is a sample of combination of traditional architecture with the needs of ecology which is considered as eco-friendly energy. Regarding to the Asbads’ unique characteristic, functional and esthetics features, recognizing them is of special importance. The concern in this research is to know how many groups traditional windmills or Asbads in Sistan are divided to, where they spread in Iran and what are the different types of them? More of the Asbads of Iran have been located in east and south-east of Iran where valuable winds blow during the whole year. Different types of 120-day winds blow in north of Sistan and south of Khorasan in second half of warm season. Asbads with traditional and domestic style provide opportunity for residents to utilize renewable energies. Different types of Asbads have spread all over “big Sistan” which are constructed differently according to the circumstances and ability of residents. Due to this fact, some of them have simple and rural forms and the others are more complicated. However, their functions are the same but their sizes and their efficiencies are different. Studies show that we can break Asbads down into the three groups such as simple Asbads, cylinder Asbads and corridor ones.

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In the last decade, there has been more attention towards the assessment and improvement of construction  phase embodied energy. In addition to buildings maintenance energy, large amounts of energies are consumed in construction process which is called embodied energy. This research results from recording all types of energies used in construction phase and presenting a numerical calculation method to assess the embodied energy of area unit and also decreasing this energy to its lowest possible limit. In order to achieve the minimum embodied energy, three energy consuming phases are calculated for 1400 square meter case study; which are material embodied energy, transportation energy and erection and on-site energy. Deviation of total embodied energy for the area shows 795.14 GJ/M2 as embodied energy. This digit is a reliable benchmark for comparing these three energy consuming phases and also comparing this construction system with other ones. Total embodied energy it the result of all three parts. But analysis of them shows that it's necessary to substitute some materials with more optimized ones. The result of this substitution decreased the embodied energy to 12.75 GJ/M2 and which is about 1.6% of the first measured embodied energy.

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The growth of energy consumption in modern societies has confronted world with threatening changes along with the peril of depletion of fossil resources. Therefore, exploiting the methods of sustainable design has found a high status in international planning and policy making.The most energy consumptions are happening in the building industry, about 40%, and the major part of which is spent for cooling, heating and ventilation. Therefore, using suitable measures to reduce energy consumption has a great influence on energy balance of building. Solar energy for natural ventilation has been used for centuries. Air ventilation is necessary for removing or depleting pollution that can be supplied through solar chimney. Solar chimney is a simple idea to increase natural ventilation in surrounding spaces by using solar energy and chimney effect in an air gap. The driving force in solar chimney is buoyancy force. The solar energy absorbed by chimney causes heat up the air in the chimney so that the air flows upward because of the stack effect. That can be a driving force to enhance natural ventilation. Therefore, the breeze inside the space lets the fresh air enter the space through window. There are a lot of cases which show the use of solar energy for ventilation by some absorption effect in building. The commonest design of solar chimney for ventilation is in vertical form. In the present study, the effect of solar chimney on ventilation rate has been examined in four cities of Iran with different climates. The cities were Rasht (moderate and humid climate), Tabriz (cold climate), Isfahan (hot and dry climate), Bandar Abas (hot and humid climate). Due to the lack of access to the implemented samples, the computerized simulation was used as an alternative method for field studies, the results of which by Energy Plus software in four cities of different climates show that the most suitable city is Isfahan (hot and dry climate) and the maximum ventilation is obtained there. There are also other factors that impacts solar chimney efficiency. Three cities (Isfahan, Yazd, Shiraz) of hot and dry climate were investigated to define their impact of latitude on ventilation rate.

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The objectives for this study were first to understand and estimate energy consumption in each stage of production and processing of milk using regional data and second, suggesting improvement opportunities. A cradle to gate assessment of market milk was performed by separating the system into three stages: agronomy, animal farm and processing plant. Data were collected from multiple sources e.g. questionnaire, published papers, national and international databases, and the processing plant database. Throughout the study, ISO framework and International Dairy Federation guideline on life cycle assessment were used. The functional unit (FU) was one liter of pasteurized milk packaged in plastic pouch at the processing plant gate. The average energy demand for producing 1 kg of fat-protein corrected milk at farm-gate was 10.8 MJ, although for the final packaged milk, it was 12.5MJ. Main stages in overall energy use of FU were agronomy 68 %, animal farm 19 % and processing plant 13%. The average energy use for raw milk production was 2-5 times higher than previous European reports. To enhance efficiency in this sector, we need to assess other regions’ potentials for feed and milk production and then to focus on agronomy stage for lower energy use by optimization of irrigation, or even importing energy intensive feed such as barley and alfalfa from other countries.

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There is a close relationship between economic growth and energy consumption. Price is one of the most important parameters which affect energy demand and consumption. Thus, investigating the factors which affect the pricing of different forms of energy is very important. The purpose of this study is to identify and rank the most important factors that influence the pricing of renewable energy in Iran. In this study, we use Analytic Network Process to combine social, economic and environmental aspects in order to provide a comprehensive view about the most important factors affecting renewable energy pricing in Iran. The results show that in 1392, economic, financial & technical factors are respectively the most important factors in pricing of renewable energies in Iran.    

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RNAs play a fundamental role in many biological and medical processes and the activity of RNA is directly dependent to itsstructure. Designing RNA structures is a basic problem in biology that is important in the treatment and nanotechnology. In this regard, some algorithms have been formed to predict RNA secondary structure. In this paper, we present an algorithm to accurately predict RNA secondary structure based on minimum free energy and maximum number of adjacent base pairs. This algorithm stands on a heuristic approach, which employs a dot matrix representation of all possible base pairs in RNA. Afterward, stems are extracted from the dot matrix and decreasingly sorted based on their length. Then the stems with equal length are increasingly sorted according to the free energy. Finally, the stems are orderly selected to form RNA secondary structure. The proposed algorithm is performed on some datasets containing CopA, CopT, R1inv, R2inv, Tar, Tar*, DIS, IncRNA54, and RepZ in the bacteria. Experimental results showed high accuracy of 95.71% of the proposed algorithm. This algorithm is run in lower computational time in comparison to the other similar approaches.

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Presently, energy suppliment is considered as a pivotal economic and political characteristic in government; so that, an increasing trend in energy price appears in countries namely Iran due to energy resources limitation and increasing costs in extraction and exploitation. Therefore, parallel to efforts made to tackle the energy upgrading costs and lackness, improving energy efficiency and conservation in buildings are considered as main solutions to address the problem. Addition to applying thermal insulation in buildings, it is extremely significant to emplement energy-efficient strategies and approaches to decrease energy transfer rate in construction sector. Undoubtedly, following approaches positively influence buildings energy balance over a year. Directly influenced by climatic condition, building elements specifically, roofs, play an important role in heat transfer rate in a structure There are thermal exchange between roof and ambient temperature including: 1) Heating ignorence 2) Heating absorption 3) and finally solar reflectance). Furthermore, roof coverings compose a large area of buildings envelope; accordingly, it has a major impact on energy consumption and thermal comfort even considering construction roofs area in urban scale. Regarding to previous research experiences, there is a large scope of data on buildings envelope details to level down energy consumption; however, less studies are devoted to building elements shape to formally analyze energy consuming. The following paper develops the studies on roofs shape thermal behavior based on building heating load; while it uses a computerized simulation methodology as an alternative to field-based research. The simulation weather date is based on Isfahan city, in Iran. Modeled and analysed four roof covering types (flat roof, domed roof, pitched roof (30°-60°), pitched roof 45°), the final result shows that however the flat shape roof appears in an appropriate thermal performance, (30°-60°) pitched covering (mostly faced to the south in terms of surface) is regarded as the most energy-effecient form in Isfahan hot and dry climate area while domed shape roof appears in mostly inefficient sample to apply as covering in the area owing to most surface area. Moreover, the graphs show that applying thermal insulation as a layer in different roof shapes, remarkably decreases heating load over a montly simulation.

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Statement of Problem: In dealing with the wonders of creation in nature and its elements, the primitive man considers himself insignificant and inferior in front of the world and its vastness. Man considers nature to be alive and imagines a supernatural force for each manifestation of existence. Totems are inanimate. Totemism is related to systems derived from symbols or representations of human affiliations to animals, plants, and fundamental and human belief objects based on totems. Objectives: Investigating totem and totemism from a psychological point of view and finding a unique method to explore the human mind and the effects left in the design of built spaces. Research Method: It is based on analytical and descriptive studies and it has been investigated and analyzed by studying library sources and it has been compiled based on mutual relationships and comparison between independent variables and theories and totems in different religions and dependent variables. Findings: In the knowledge of totem and totemism, understanding many amazing aspects of animals, plants and objects seemed to be impossible for humans and this led to their sanctification; Of course, the holiness that followed fear and respect. Such a view and thought caused the emergence and spread of beliefs such as animism, reincarnation and totemism. Conclusion: Totemism and belief in totems and taboos was one of the ancient beliefs and a topic related to the history of early humans, which is considered one of the early examples of human religions. The practical consequences of these beliefs in the lives of early humans led to the emergence of rituals and practices in which the importance of animals and plants was emphasized, whose effects on the design of spaces and beliefs of the current generation are clearly evident.

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The building sector is responsible for one-third of global final energy consumption and thus environmental damage, carbon dioxide production. Some reasons for ever increasing building energy consumption : climate change, increase in household electricity load , the growth of real estate, fast-growing household electrical appliances, changes in industrial structure, huge energy consumption of the existing buildings, and the lack of strict government supervision. The world's total energy requirements are mostly used in sectors such as transportation, industry, residence, commerce, etc.. Although most of the energy consumption during the period 1973 to 2009 belonged to the industrial sector, it can be said that the proportion of residential buildings is very high and is increasing rapidly.. World Statistics published by the Department of Energy, United States of America in March 2010 shows that most houses widely use energy for heating and hot water and then cooling and lighting. Therefore, the revision of quality architectural design of buildings, based on the climatic principles , will be very effective in optimizing fuel consumption so that the energy consumption can be controlled wisely and optimally. On the other hand the use of renewable energy technologies can provide energy surplus of buildings and eliminate the problems associated with fossil energy in great extent.Adopting conservation measures on a large scale does allow reducing both electricity and total energy demand from present day levels while the building stock keeps growing. They simulate climate-dependent hourly building energy demands at user-defined scales, typically an individual state or utility zone. Due to the effective role of energy in economic development and its increasing consumption in parallel with the growth of human communities , considering resource constraints and preventing from facing with an energy crisis, the need for conservation through management application is necessary which demands new strategies and approaches in both environmental and architectural revisions for design and building. In particular, the high energy consumption especially in buildings is a major problem in developing countries which has economic and environmental impacts of prime importance while it is considered to be the most significant cornerstone of growth in different dimensions. Buildings , it is statistically shown, account for a third of total global energy consumption. Energy consumption in buildings is increasing due to several factors including climate change, increasing electrical energy consumption in households, real estate development, diversity of modern appliances, changes in industry structure, very high energy consumption in existing buildings and the lack of adequate supervision of the state.. Therefore, efforts must be focused on the control and management of energy consumption . The purpose of energy management is reducing energy consumption in a way that is logical and economical and can cause no negative effects on welfare and thermal comfort. So, a focus for building energy consumption efforts is of great importance. The occupant behavior and building manner can both increase the building energy consumption, especially residential ones.In the building quality part, there are many techniques affects on building energy consumption, which divide to passive and active. The passive ones are the techniques that related to the body and design of a building as material, utilization of solar radiation on the bodies, length and width of building, insulation, window, and so on without electrical or other energy portfolio, but the effect of these parameters was not equal. Therefore, this study presents an approach to determine the effect of main parameters of some of the building techniques on energy consumption. In this study, these parameters were identified and evaluated and finally were Prioritized. Not all of the parameters has equal role on energy consumption, which the mentioned weights indicated. The remainder of the paper organized as follows. Firstly, the parameters were identified by research and interview. The effective parameters recognized as the alternatives of the mentioned hierarchy3 step trees, which can be listed as follows: occupants; built area; Step No.; Proximity degree; Window to wall ratio; Length to width ratio; Side. Secondary, the questionnaire performed and completed by experts as architects, mechanical engineers and energy engineers. Analytic hierarchy process (AHP) and its applications in surveys related to buildings were presented. Up to now, the AHP method has been widely applied in the general policymaking in buildings. Next, the effective parameters on energy consumption evaluated, and in next section the AHP for the approach concernedexplained and resultsoffered. Finally, the last Section includes the concluding remarks. The weights and priorities of the effective parameter are illustrated. As a result, considering weight of factors in building designing process, the different parameters of BO can be classified and evaluated: First, the main effective parameter is window to wall ratio. Depends on the weight of this parameter (0.36), the window area and materials are important for building designers. Another main parameter is side no., if a building has 1 or 2 or 3 or 4 side, its energy consumption differs fundamentally. Choosing the main direction, side and the side no. are all associated. One of the main results is about the building area depending on energy consumption, which considers having the main role, but in present survey concluded that the third effective parameter is area. The least effective parameter is occupant number, due to energy load of building space and quality, not building occupant. Urban designers and Architects considering Building Orientation (BO) and its parameters can design buildings that are energy efficient. If building orientation )BO( is considered, solar radiation absorbed by the surface structure of the building will become more favorable, and consequently the energy consumption will be reduced. However, if the building orientation (BO) is considered along with climatic factors, there will be direct effect of increased energy costs. In addition , urban designers must greatly pay attention to building sides while determining the building blocks as the transmitting surfaces are from outdoor to indoor in summer and vice versa in winter. Architects must also pay attention to different ratios of windows to create the proper ratio of heat transfer in the buildings. The materials used in the buildings are of great importance.

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Pinch technology used as a tool for energy calculation and target design in context of energy optimization. In 2004, After enthalpy-exergy analysis for Chahar mahal beet sugar factory and applying some changes in heat transfer system, the steam consumption per beet decreased by 34% compared previous year. To enhance the efficiency of energy utilization, pinch analysis was employed to get a better insight into the energy situation in 2004. Based on the results obtained, three tubular heat exchangers were added to the heat exchanging system at a position which by exergy analysis was founded tobe the best, The results showed that the steam consumption per unit weight of beet sugar decreased from 54% in 2004 to 46% in 2005.

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Hypothesis: The aim of this research was the investigation on kinetic of curing reaction of polyurethane binder based on hydroxyl terminated polybutadiene (HTPB). This reaction is of particular interest in advanced polyurethane composite materials.
Methods: HTPB diol was dynamically cured using differential scanning calorimetery (DSC) at different heating rates (5, 10, 20 and 40° C/min) with curing agents of Toluene Diisocyanate (TDI) and Isophorone Diisocyanate (IPDI) in presence and absence of Dibutyltin Dilaurate (DBTDL) catalyst. Kinetic parameters were calculated using Kissinger, Ozawa and isoconversion models. Urethane formation and viscosity build-up during cure reaction was studied by Fourier Transform Infrared Spectroscopy (FT-IR) and rotational visocmetery (RV) methods.
Findings: Results showed that activation energy, enthalpy, progress and the rate of reaction were influenced by type of curing agent and the presence of catalyst. Kinetic models showed activation energy was reduced about 1 kJ/mol at each 0.05 unit increase in the degree of cure. The activation energy of HTPB-TDI-DBTDL binder system versus degree of cure was reduced slower in comparison to HTPB-IPDI-DBTDL binder system. Decrease in activation energy at degrees of cure higher than 90% was intensified as probable diffusion of low molecular weight molecules into polymer chains. Enthalpy of reaction in HTPB-TDI-DBTDL binder system at heating rates of higher than 10° C/min was independent of heating rate, whereas in HTPB-IPDI-DBTDL binder system the enthalpy of reaction is highly dependent on heating rate. Chemorheological results showed that rate of curing reaction for binder systems are in the order of HTPB-TDI-DBTDL>HTPB-IPDI-DBTDL>HTPB-TDI.

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Research subject: Solar cells has gained a great attention as a green, renewable and cheap energy resources. To overcome the challenging technical problems and improve their competitiveness with silicone solar cells, the design, synthesis and development of new materials with engineered band gap energies has found an undeniable importance.
Research approach: Herein, the synthesis of a polymer with donor-acceptor structure based on polyaniline grafted to ZnO nanoparticles at one end and naphthalene moiety at the other end of chains, and investigation of their chemical structure, composition, morphology, optical and electrochemical properties is reported. The chemical structure of the materials were analyzed by FT-IR and ¹H NMR spectroscopy. The organic and inorganic contents of materials were determined by thermal gravimetric analysis (TGA) and atomic absorption spectroscopy (AAS) techniques. The morphology and size of nanoparticles were observed by scanning electron microscopy (SEM). The optical and electrical band gap energy of the samples were measured by ultraviolet visible-diffuse reflectance (UV-Vis-DRS) spectroscopy and cyclic voltammetry (CV) diagrams.
Main results: The chemical structure of designed materials has been successfully confirmed by the results of FT-IR and ¹H NMR spectra. TGA and AAS analysis have indicated that the synthesized final material has contained about 10% of ZnO and 90% of organic parts including toluene-2,4-diisocyanate, 2,4-diaminotoluene, polyaniline and naphthalene groups. An almost highly uniform spherical nanoparticles with sizes about 70 nm has been observed by SEM images. UV-Vis-DRS spectroscopy and CV diagrams have revealed that by grafting ZnO nanoparticles and naphthalene moiety to the polyaniline chain ends, the optical and electrical band gap energy of the sample were lowered to 1.19 and 0.95 eV, respectively. It was concluded that the grafted groups to chain ends has increased the length of conjugated system, lowering the energy level of lowest unoccupied molecular orbital (LUMO) and increasing the energy level of highest occupied molecular orbital (HOMO). Detailed analysis of CV diagrams has indicated that the effect in lowering of LUMO has been a bit more pronounced than the increasing of HOMO energy level.

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