sphalt is the most recycled materials around the world and the amount of RAP materials can be significantly increased with the application of good RAP management applications. In Iraq, the real inclusion of RAP materials in asphalt mixtures has not been applied yet in the field. It is therefore that there is a need to characterize the effect of inclusion RAP materials in asphalt mixtures with particular reference to permeant deformation/rutting resistance. The aim of this study is to evaluate the best layer of pavement structure; base, binder, and surface layers for inclusion (RAP) materials. In addition, highlight the best percentage that can be added from RAP to achieve positive results and better than that associated reference mixture in terms of rutting resistance. RAP materials collected from different sources Karbala and Fallujah, were adopted in this study at percentages of 20%, 30%, and 40% by weight of the asphalt mixture. Two scenarios of incorporating RAP materials have been adopted. The first is considered that RAP as a black rock in which the effect of aged binder surrounding the aggregate of RAP is neglected while, the letter is not considered RAP as black rock and the influence of aged binder in RAP materials has been taken into consideration. Dora bitumen has adopted in the current study which is used in common in Iraq. It has been highlighted the best layer in which RAP can be incorporated is the base layer, with a percentage up to 40% that RAP without considering RAP black rocks regardless the sources of RAP.
Since FGM orthotropic structures have such striking qualities as high strength, exceptional stiffness, stiffness-to-weight ratio, reduced cost, and high strength-to-weight ratio, they are employed extensively in the mechanical, aerospace, and civil engineering sectors. Thick plates and shells have more noticeable shear deformation effects. Therefore, in recent years, there has been a lot of interest in the vibration and buckling investigation of FGMs orthotropic plates and shells. Moreover, researchers have developed a variety of approaches and procedures for the examination of orthotropic FGM plates and shells. The majority of the literature review in this publication is focused on orthotropic FGMs plate and shell buckling and linear and nonlinear free vibration. In engineering practices, it is customary to use material-oriented or orthotropic materials in several domains to optimize the structures and maximize material properties, which is especially crucial for FG constructions. Solutions for the orthotropic FGM structure are studied analytically and numerically with different plate and shell theories.
Reverse osmosis (RO) is a membrane filtering system that uses a semipermeable membrane to remove contaminants from water before sending the purified water on to be used in a number of settings, such as households and factories. The goal of this study is to investigate the process of reverse osmosis as well as the current status of the membrane materials that are used in the process. These membrane materials are the driving elements in the process. This review also includes a discussion on the cleaning of membranes, the utilization of RO systems for a number of applications, and new advancements in the field of reverse osmosis. In the process of cleaning water, reverse osmosis, also known as RO, is a potent technique that makes use of a semi-permeable membrane to remove hazardous bacteria as well as dissolved particles. This technique is utilized on a regular basis for the purpose of desalinating seawater for use in drinking, agricultural, and industrial applications.
This study aims to examine the relationship between the corrosion rate of longitudinal tensile steel bars and the maximum flexural strength of reinforced concrete RC beams. The study's methodology is designed to show the structural behavior of corroded and non-corroded RC beams, such as ultimate load, deflection, stiffness, crack patterns, and failure mode. Three rectangular beams were cast with dimensions (150× 200 ×1200) mm, and all specimens have the same amount of longitudinal and transverse reinforcement and the same concrete strength. The major parameter is the theoretical mass loss level due to corrosion (0, 10, 15) %. Electrochemical technique was used to accelerate the corrosion in the longitudinal tensile bars. All RC beams were tested under four-point monotonic loading. The test results confirm that the cracking load in corroded beams decreased by 25% comparative to the non- corroded beam. The increase of the percent of corrosion experimental mass loss by 8.25 and 14.15 % decreased the ultimate load by about 14 % and 27%, respectively. This reduction coincided with the decrease in deflection values in mid-span for the ultimate load, which decreased by 53.9% and 46.3%. However, the flexural stiffness was reduced by 13.4 and 15.6% for corroded beams with mass loss (8.25 and 14.15), respectively, compared to the control beam (non-corroded RC beam).
Concrete structures suffer from the impact of many harmful attacking materials that affect theproperties of the main material in them, which is concrete. These structures are also, exposedto the negative impact of many hostile environments such as soils containing harmful salts andharmful acids. A number of precautions should be considered in order to protect the concreteused in such structures. Adding polymer to concrete components as a percentages weight ofcement is one of the methods for producing polymer-modified concrete, which has lowpermeability, better mechanical properties and is more resistant to the negative effects ofharmful environmental factors. The utilization of polymers could help in protecting structuresand enhancing concrete strength. In this study, concrete mixes were prepared with inclusion ofstyrene butadiene rubber (SBR) polymer at four percentages (0%, 5%, 7% and 10% by cementweight). Co-polymers of butidine with styrene (styrene-butadine rubber (SBR)), are a group oflarge-volume synthetic rubbers. High adhesion occurs between the polymer films that formand cement hydrates. This action gives improves the properties of concrete such as flexuraland compressive strength and gives also a higher durability. The investigation was extended toevaluate the compressive strength of the SBR concrete mixes immersed in three types ofwaters: tap, drainage and ground water, at three different ages. The results showed that SBRpolymer enhanced the compressive strength of concrete significantly. A comparison betweenreduction in strength of concretes immersed in these three types of waters was also presented.Moreover, the presence of SBR polymer led to reduced loss in strength of concrete specimensimmersed in drainage and ground water. A proposed model to determine the compressivestrength of concrete specimens immersed in drainage and ground waters was deduced. Thismodel could be a helpful tool for rapid and easy estimation of the strength of concretespecimens immersed in drainage and ground water at different contents of SBR polymer. Theresults showed the highest improve in compressive strength to be associated with 7% SBRmixes at the three tested ages. The increases in this strength at days 7, 28 and 56 with inclusionof 7% SBR polymer were 112.8%, 113.9% and 116%, respectively, compared to OPC mix.
Recently, the sustainability issue has become crucial to operation, which motivates researchers to search for naturally generated, sustainable materials, especially in automotive applications outside of reduced prices and enhanced performance. Glass-linen/Polyvinyl Butyral hybrid composites' mechanical characteristics were examined in relation to the effect of linen fiber loading. The composite and hybrid composite samples of linen/glass fiber reinforced PVB film were created using a hot press with various layering patterns. The results were high impact values with increased both tensile and flexural strength values. Compared to other hybrid composites, the mechanical behaviors of the H1 (Glass / Linen) hybrid have a greater tensile strength measuring 401.30 MPa, while, H2 (Glass / Linen/ Glass) hybrids are found to have the highest flexural strength, measuring 160.80 MPa. An optical and scanning electron microscope morphological analysis on linen hybrid composites revealed good results. This indicated decreased rates of delamination between the fibers and matrix layers. The loading of the fibers was shown to have varying effects on the composite's mechanical behaviors. The linen/glass composites also demonstrated strong interfacial adhesion, which enabled the PVB-phenolic resin to penetrate the fiber bundles and produce a matrix with the good interlocking of the fibers
Friction welding method is one of the most efficient and effective techniques for joining similar and dissimilar materials. The AISI 304 austenitic stainless-steel is a most common type of austenitic stainless steel which is used in various practical applications like automotive, food manufacturing, chemical applications, etc. Therefore, the impact strength and microstructure behavior of friction welded AISI 304 austenitic stainless-steel joints were investigated. The specimens were divided into two groups, the surface of the first group was flat while the interface of the second group was designed by fabricating a pin and hole. The effect of different forging pressure (192.4, 240.5, 288.6 and 384.8 MPa) on impact toughness and microstructure behavior of AISI 304 were examined using Charpy impact tester and optical microscope, respectively. The minimum impact strength was observed at 240.5 MPa for flat interface samples whereas, the maximum impact strength value (0.5675 J/mm2) was at 388.6 MPa forging pressure for pin interface samples. In addition, the ductile mode in pin type for all cases while both, brittle and ductile mode in the flat joint was noticed. Finally, it was concluded that the impact strength improved with designing a pin and hole shape at the joint interface.
Problematic soils, especially clayey soil, are problematic for engineering projects in their natural state because of clay's swell-shrinkage phenomenon. Numerous methods and stabilizer materials have been used to enhance clay's geotechnical properties and make them appropriate for construction. One of the significant methods of stabilization of problematic soil is using waste materials like waste glass, waste stone, waste plastic, etc. Due to the waste stone's consistency reducing water content and increasing the soil's strength, it has been employed in many civil engineering studies. Waste stone is available in various forms, including waste stone powder (WSP). WSP is produced by blasting tunnels or cutting huge stone blocks. Hence, the main aim of this study is to review the influence of WSP on improving the geotechnical properties of problematic soils treated with WSP, for this purpose, the treated problematic soils with various percentages of WSP are compared with natural soils. This study evaluates physical properties (i.e., Index properties, linear shrinkage/swelling, optimum moisture content, and maximum dry density) and mechanical properties (i.e., unconfined compressive strength and California bearing ratio). Also, the effect of WSP on decreasing the thickness of pavement layers was reviewed
These systems show great promise by converting waste heat from photovoltaic modules into additional electrical power. The study analyzes the performance and efficiency of the hybrid PV-TEG systems under varying conditions, such as different solar concentration ratios, cooling methods, and materials. While these innovations promise to improve system efficiency, the review also identifies several challenges, including increased thermal resistance, higher system costs, and the minimal temperature difference across the TEG, which significantly limits its performance. This limitation, where the temperature differential is often too small to be effectively harnessed, reduces the TEG's overall efficiency and hinders the integrated system's potential gains. The review underscores the need for urgent and extensive research to develop optimized design configurations, durable mathematical models, and further experimental validation to ensure the practical viability of these systems under diverse environmental conditions. Despite these challenges, the potential of PV-TEG systems to revolutionize solar energy technologies is undeniable.PV-TEG performance is intricately linked to environmental conditions: higher solar radiation boosts efficiency, but increased ambient temperatures reduce it. TEGs often hinder PV cooling, yielding minimal efficiency gains. Non-uniform heat and low-temperature differences across TEGs further decrease performance. While hybrids can improve power conversion, high costs limit feasibility. However, with strategies such as enhancing solar concentration, using effective cooling methods like water or nanofluids, and advanced materials like phase change materials, the efficiency and reliability of these systems can be significantly improved
The aim of this article is to investigate the properties for joints of welded martensitic stainless steel (MSS) by ER 309 L filler wire, using tungsten arc welding (Tig). The regions of the base and welded materials were investigated by means of SEM, EDS, OP and HV were conducted to calculate the properties of the welded specimens. The influence of heat and cryogenic treatments also investigated, The best results from microstructure side occurrence epitaxial grains growth which was observed along the interface of weld-metal region, the maximum hardness was (414 HV) in conventional heat treated samples that tempered at 200°C, precipitation of small carbides were observed that this is responsible for the improvement in the mechanical properties of the material. Hardness at the HAZ region in state of DCT in all weldments was reduced as compared to hardness of HAZ region of CHT. The microhardness was at the highest value in the fusion zone
The term "fire safety engineering" refers to the process of applying scientific and engineering principles to the effects of fire in order to lessen the number of deaths and property damage caused by fire. This is done by determining the risks that are involved and providing the most effective method for implementing measures of prevention or protection. The paper showing experimental results of ordinary concrete columns made of "NSC" subjected to axial load and cyclic firing is presented in this study. the bearing capacity of the column decreased. all samples have been loading an eccentric load with "e = 75 mm" ,"e / h = 0.50," and the ratio Celsius (30%Pu) continuously through the burning period. The first column(C1) was the sample control with out exposure cyclic fire , and the second column was subjected to four burning cycles over the course of four days, with a duration specific of "45 minutes" for each cycle, at a temperature of "400 °C", and the third column was subjected to four burning cycles over the course of four days, with a duration longer amount of "75 minutes" for each cycle, at a temperature of "400 °C, ", the four column was subjected to four burning cycles over the course of an of four days, with a duration specific of "45 minutes" for each cycle, at a temperature of "600 °C " , the bearing capacity of the column decreased. that to be amount losses (C2,C3 and C4) comparison to (C1) equile ( 27.20 , 29.12, and 36.40)% respectively. the fracture load of the experimental columns varied by decreasing with these variables. Additionally, the depth and spread of the cracks increased with the increase in burning duration and target temperature.
Advanced prosthetics are a crucial aspect of rehabilitation technology and are receiving increased attention globally. Approximately 2 million people require prosthetic limbs, presenting opportunities for enhancing their quality of life. State-of-the-art technologies such as realistic arms and myoelectric prostheses are gaining popularity. Progress in sensor technology, artificial intelligence, and materials has driven the field forward. Various types of controllers, including direct, pattern recognition, and proportional-derivative, have been developed. Integration of material science, computer science, artificial intelligence, and neurology has facilitated controller advancements. Techniques like targeted muscle reinnervation and Osseo integrated prostheses offer improved surgical options. Gesture recognition technologies and intelligent sensors are enhancing hand control. Future advancements will involve machine learning, artificial intelligence, and sensing techniques, while ethical concerns must be addressed. Advanced myoelectric prostheses, also known as myocontrolled or lower-limb micromod investigative prostheses, have a patient acceptance rate of 75% to 80%. However, while these methods offer advantages, there are also drawbacks. Integrating different types of controllers for these smart prostheses and enhancing the overall device's strength and robustness will have a significant impact. This discussion focuses on various types of smart prosthetic controllers, dividing muscle activity into extracellular myoelectric potential and EEG signals
Recently, the use of sandwich panels has become increasingly important. This is due to its good mechanical properties and high strength-to-weight ratio. It is used in many fields, especially in aviation, construction and aerospace. It is necessary to know the behavior of the materials used, especially the free vibrations, to know the effect of external factors on the sandwich panels. The honeycomb core sandwich panel was studied. A model for analysis and modeling is proposed. A previous model was chosen for analysis and comparison. Hoff theory was applied to convert honeycomb sandwich panel into equivalent sandwich panel to facilitate the solution and save time. The limits were considered fixed on the one hand and moving on the other hand, and the ANSYS program was used to analyze and extract the results, and the results were compared and were promising and accurate, which proves to us the validity and accuracy of the proposed theoretical results
The porous Titanium is characterized by high permeability which can assure the ingrowth of bone tissues, and consequently results in a good bonding between the metallic implant and the bone. In this work, Silicon element was added to the Commercially Pure Titanium at different weight percent of (2, 4, 6, 8 and 10) to investigate its effect on the porosity percentage, mechanical properties of the resulted samples. XRD analysis stated that at (Si) content lower than (2 wt%) the alloy is single phase (α- Ti alloy), as the Silicon content increased, in addition to (αphase), (Ti5Si3) intermetallic compound developed in the alloy. Porosity measurement results showed that the porosity percentage increases with the increase in Silicon content. Wear results stated that the wear rate increases with the increase in silicon content due to the increase in porosity percentage while the hardness results stated that there is no significant effect for Ti5Si3 intermetallic compound on improving the hardness of the samples. This is attributed to its low percent and the major effect of porosity on hardness which declined the effect of Ti5Si3 by reducing the hardness of the alloy compared with the master sample. The obtained results of the (yield strength, ultimate compressive strength and Young’s modulus) were within the values that match bone’s properties. This means these materials are suitable for biomedical application
In recent decades, functionally graded porous structures have been utilized due to their light weight and excellent energy absorption. They have various applications in the aerospace, biomedical, and engineering fields. Therefore, the balance between material strength and light weight is the goal of the researchers to decrease the cost. Samples of PLA material were designed and manufactured using a 3D printer according to international standard specifications to study the effect of porosity gradient through thickness. An experimental three-point bending test was performed, and then simulations were performed using ANSYS 2022 R1 software on samples with functionally gradient different porosity layers to verify the experimental results. The results from the experiment and the numerical values were in excellent alignment with an error rate of no more than 13%. The maximum bending load and maximum deflection of the beam were specified experimentally and compared with the numerical solution. The maximum bending and the maximum deflection When the porosity layer in the middle of the beam, matched the ideal maximum bending load (190,194) N experimentally and numerically, respectively. The maximum deflection (5.9,6.4) mm experimentally and numerically, respectively was obtained in samples with varying porous layers.
Since concrete is one of the most popularly utilized building mixtures in construction, a high demand of natural resources is significantly emerged. Therefore, a skyrocketed attention has been paid to create new opportunities for the use of recycle materials to develop a new construc-tion substance with more satisfactory properties. The use of waste products in concrete is not only economical, but it helps in solid waste management as well. Among various properties of concrete, thermal conductivity is a crucial factor that plays an important role in in building insu-lation by evaluating a material's capacity to transfer heat. This paper aims to review the potential application of waste materials in concrete as additive ingredients and investigate the effect of this waste material on thermal conductivity of concrete. The review of literature revealed that the application of most of the waste materials exhibited an obvious potential as thermal insulator. However, further investigated work is needed to highlight the advantages of utilizing waste mate-rials in concrete containing various type of waste materials
Density separation has many applications in metallurgy, medicine, clinical chemistry, microbiology, and agriculture. This study investigates the factors' effects on density separation in order to benefit from this technique. The separation quality depends on the velocity of particles because as the velocity of particles increases, the mean separation needs less time so it gives better separation, so the parameter effect on the value of the velocity is studied. These parameters were volume fractions, the diameter of the sphere, the density of the sphere, and the viscosity of the fluid. Each parameter was studied by calculating the velocity of particles using Stokes' law. The velocity of particles is directly proportional to some properties of particles. These properties are the diameter and density of a particle because as these properties increase, the mass of particles increases, which leads to increased kinetic energy, which increases turbulence. Turblance's velocity is increasing. The volume fraction of spheres is another property of particles' effects on density separation. This parameter is inversely proportional to velocity because a collision between particles increases, which decreases turbulence. Fluid properties also have an impact on density separation. This property is viscosity. Its effect deteriorates the efficiency of separation because viscosity is the resistance of the fluid to flow that serves to displace the particle, which leads to a reduction in the velocity of the particle. The maximum separation happens when the sink and float particles separate at the same time. That happens when the sink and float particles have the same velocity in the opposite direction. That means when the sum of velocities equals zero. In this research, the maximum separation was derived when the sum of velocities equaled zero.
Turning is the most popular machining operation. The quality of the product may be determined using a variety of metrics, such as the surface generation method and the surface roughness of the product. This work uses cutting variables to obtain the best surface quality through a mathematical model. The suggested surface generation in this work results from deriving it using the Bezier technique, with degree (5th) having six chosen control points. One of the critical indicators of the quality of machined components is the surface roughness created during the machining process. Surface roughness improvement via machining process parameter optimization has been extensively researched. The Taguchi Method and actual tests were employed for evaluating the surface quality of complicated forms; regression models with three different variables for the cutting process, such as cutting speed, depth of cut, and feed rate, were also used. According to the experimental findings, the most significant effect of feed rate on the surface roughness is approximately (40.9%), and the more minor effect of depth of cut on the surface roughness is almost (16.23%). In addition, the average percentage error is 4.93%, the maximum error is 0.14 mm, and the minimum error is -0.143 mm for the prediction using the regression equation.
The extensive global competition between companies and the development of new industrial technologies have greatly contributed to the current competitive conditions Like industrial companies, customers demand high quality products, low prices and better performance. This fierce competition has led to concerns about improved product design. This development is based on GQFD. Model of this developed Water pump is employed by CAD solid model (version 7). In order to achieve competition and high quality and high performance in the Iraqi market. GQFD demonstrates the balance between product development and environmental protection. Used a water pump for a home air cooler as a case study. Data is collected and distributed using personal interview methods and questionnaire forms to indicate customer requirements. The data is then analyzed using Pareto chart and AHP to prioritize customer needs. These priorities are then placed in house of quality and matrix of relationships between customer requirements and technical characteristics is established. The product has been developed from electrical to mechanical, in addition to using accumulated, stored and recycled materials; it also saves 20% of energy, thereby combining energy reduction with the use of damaged materials and their re-entry into work. As a result, the cost of pump manufacturing will decrease
Scientists have recently started looking for new ecologically friendly and sustainable materials. Construction materials are among the numerous widely employed materials, and it is normally acknowledged that they have an apparent detrimental influence on the environment. Thus, the contribution of this paper is to describe the palm frond natural fibers' effect on concrete's mechanical characteristics. Since concrete is a brittle material, the goal of this research is to increase the tensile strength of concrete by using organic fibers (palm frond fibers), a waste product. In order to determine the ideal percentage of fibers, the following percentages were tested: 0.25, 0.5, 0.75, and 1% by volume of concrete. On dry density, compressive strength, and tensile strength, the impacts of fibers were investigated. The density of concrete decreased with increasing fiber ratios. The compressive strength slightly decreased, while the splitting strength significantly improved. According to the results, the best amount of palm frond fibers that can be add to concrete is 0.75% by volume.
Deep mixing technology is used to improve the engineering properties of soil. In this review, previous studies on the properties and problems of weak soils were collected and explained, focusing on silty soils found globally and locally. The study also includes a discussion of physical and chemical improvement methods, specifically (cement columns). The advantages of deep mixing technology are also covered from an engineering and economic point of view, as well as its relationship to the environmental impact, as it is one of the sustainable development techniques due to its use of environmentally friendly materials. In addition, one of the objectives of this research is to study the methods of adding cement, whether in the form of powder (dry method) or mortar (wet method). A comparison was made between them to clarify the advantages and disadvantages. It was found that what distinguishes the use of the dry method from the wet method is that the former is more common. The method's effectiveness depends on the soil's moisture content, so the technique is ineffective in soils with less than 30% water content. As cement hydration produces a cementitious gel (CSH) that binds soil particles together, leading to early strength gain, pozzolanic reactions cause increased shear strength and decreased soil compressibility. Finally, some recommendations are included in this article to understand the behavior of cement columns in improving soil and avoiding problems
A finite element method for free vibration analysis of generally laminated composite plateswith central crack and clamped edges have been studied using ANSYS 5.4 program. The fiber-reinforced composite materials are ideal for structural applications where highstrength-to-weight and stiffness-to-weight ratios are required, where structures must safelywork during its service life. But damages initiate a breakdown period on the structures.Cracks are among the most encountered damage types in the structures. The non-dimensionalfundamental frequency of vibration decreases with presence of cracks because, therigidity of cracked plate decreases. The natural frequency of plates depends on size andshape of the cracks, the effect of number of layers is found to be insignificant beyond fourlayers and the change of fiber orientation increasing the fundamental frequency of vibration.The results obtained have been compared with the available published literature with goodagreement results
The concrete members several blessings over steel beam, like high resistance to prominent tem-perature, higher resistance to fatigue and buckling, high resistance to thermal shock, fire re-sistance, robust resistance against, and explosion. However there are some disadvantages as a result of exploitation totally different materials to product it. The most downside of structural concrete member is its deprived the strength to tensile stresses.The bond mechanism between steel bars and concrete is thought to be influenced by multiple parameters, like the strength of the encompassing media, the prevalence of cacophonous cracks within the concrete and therefore the yield stress of the reinforcement. However, properties of concrete mass has significantly effect when it was subjected to elevated temperature.The objective of this paper presents the results that allocating with the bond behavior of the rein-forcement of steel bar systems below static pull-out loading tests subjected to elevated tempera-tures. This numerical technique relies on relative slip and therefore the stress of bond distribu-tions done the embedded length and size of the bar within the concrete cylinder specimens. The obtained results square measure given and commented with the elemental characteristics of ferroconcrete members. The comparison showed smart agreement with experimental results
Hydraulic structures are structures submerged or partially submerged in water, they’re used to retain or divert natural water flow. Any hydraulic structure that retains water is faced with seep-age problems as the water seeks the path with the least resistance through or under the hydraulic structure. If the water carries materials as it flows or exerts high pressure on the floor of the structure, it will cause failures such as piping and cracks and there are many ways to prevent that, including cutoffs. In this paper, seepage is analyzed for different cases by using the empirical method (Khosla’s theory) and the numerical method by using computer software (SEEP/W). The results had some slight differences between the two methods as a result of not taking into ac-count the effect of soil characteristics of the empirical method. However, the water pressure heads underneath the impervious floor that calculated by the numerical method were greater
Agricultural, industrial, and household debris can be employed as biosorbents to extract heavy metals from water that has been contaminated. Kitchen waste includes, among other things, peels from promotional gates, lemons, avocados, apples, kiwis, watermelons, and onions. Moreover, coffee and tea grounds are considered to be household refuse. This review illustrates the scholarly investigations that explored the potential of various waste materials as adsorbents for wastewater treatment. An extensive array of experiments was conducted to determine the variables that influence the capacity of these materials to adsorb heavy metals. To undertake the experiments above, different concentrations of biosorbent were introduced into the effluent at various contact times and pH levels. The researchers investigated the effects of varying these parameters and found that the biosorbent's ability to adsorb heavy metals is directly proportional to these factors. The results and conclusion indicated that the impact of biosorbent concentration and contact duration on the pH of contaminated water was assessed. To encourage the incorporation of industrial, agricultural, and household refuse into water treatment processes rather than permitting it to accumulate as an environmental hazard.
Materials selection is a multi-criteria decision-making (MCDM) problems because the large numberof factors affecting on decision making. The best choice of available material is critical to thecompetitiveness and success of the manufacturing organisation. The analytical hierarchy process(AHP) is an important tool to solve MCDM problems. The choosing process of suitable material(such as a refrigerant fluid) for the Air Condition System (ACS) is faced with challenges such aslack of a systematic approach in setting the optimal performance in terms of its impact on theenvironment and operation. Selecting process for the one refrigerant from a range suitable ofsuitable refrigerant is complex process. The study presents a comparative performance analysisof ACS for using four alternative refrigerants R290, R410, R404 and R22. Then, one of these suitablerefrigerant is selected. The comparison is based on three criteria system operation, environmentand maintenance.Novels ACS performance assessment model is proposed based on an analytical hierarchy process(AHP). The model is based on two main criteria of ACS, quantitative criteria, cooling capacity(CC), coefficient of performance (COP), etc.).And qualitative criteria (Ozone Depletion Potential (ODP), Global Warming Potential (GWP) andmaintenance cost (MC)). It is necessary to look for new technique help decision making to selectalternative refrigerants, to fulfill the goals of the international protocols (Montreal and Kyoto)and optimum operation, to satisfy the growing worldwide demand, in addition the increase outdoortemperature in some countries.This study provides a developed methodology for evaluating ACS performance. Moreover, it helpsto select a robust decision. The results obtained from AHP process that the best rank of the suitablerefrigerant was R404 (0.3763) followed by R22 (0.3657) and so on for the other. Therefore,the proposed methodology can help the decision maker to select the best alternative for bothcriteria (qualitative and quantitative) in complex selecting process.
Due to the expansion of industrial operations globally in recent years, waste output has risen. So these wastes must be reduced by recycling and reusing to achieve environmentally friendly buildings and find various alternative materials in critical cases. The statistical indicators are used as practical study including Multiple linear regression (MLR) and artificial neural network (ANN) models. The study's goals were to assess the effectiveness of granite waste (GW) as a replacement for cement, sand, plastic, and binder in specific building applications and the relationships between MLR and ANN approaches. Results show the efficiency of adding granite waste to some construction stages and replacing it with cement in the mixture and examining its strength, it gave excellent results in addition to good results for its use as a binder in cement mortar, while the results were weak when used as a substitute for sand and plastic in insulator because it's classified as fine sand, Therefore, it cannot be used as a substitute for sand in the construction. The statistical models give an effective indicator to use GW as an alternative material ( binder and cement) based on the coefficient of correlation (R2) for the two models MLR and ANN equal to 83.4 % and 80 % respectively.