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.
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.
ORE addresses various kinds of losses associated with manufacturing system which can be targeted for initiating improvements. Evaluating ORE will is helpful to the decision maker(s) for further analysis and continually improves the performance of the resources. Overall Resource Effectiveness (ORE) encompasses seven factors are; performance, quality rate, readiness, changeover efficiency, availability of material and availability of manpower. In this research Job shop production of General Company for hydraulic industries, with focus on Damper and Tasks Factory (DTF)is tested as a case study for two of the most customer demand rear dampers (Samaned and Nissan). Data are collected and analyzed for years 2016-2017 to evaluate of ORE values. Results show that process performance factor among other seven factors have the less value causing the highest loss in ORE decrease. Where the highest ORE value is (58.6%) for Nissan and (69.3) for Samaned rare production. Also, time loss due to set up time is detected where it ranges from 3% to about 13% per month for the above mentioned two tested dampers. Results are generated employing Minitab Version 17, Quality Companion Version 3 soft wares. It is recommended to introduce SMED (Single Minute Exchange of Dies) concept that could decrease losses in set up time .Also improvements in maintenance programs are vital, and above all improving process performance values is essential by employing lean manufacturing that result in fast outcomes ,and TQM process improvement strategy for long term outcomes these two process performance strategies may enhance ORE values therefore, decrease losses, and consequently increase quality and productivity.
RSM and DOEs approach were used to optimize parameters for hypoeutectic A356 Alloy. Statistical analysis of variance (ANOVA) was adopted to identify the effects of process parameters on the performance characteristics in the inclined plate casting process of semisolid A356 alloy which are developed using the Response surface methodology (RSM) to explain the influences of two processing parameters (tilting angle and cooling length) on the performance characteristics of the Mean Particle Size (MPS) of α-Al solid phase and to obtain optimal level of the process parameters. The residuals for the particle size were found to be of significant effect on the response and the predicted regression model has extracted all available information from the experimental data. By applying regression analysis, a mathematical predictive model of the particle size was developed as a function of the inclined plate casting process parameters. In this study, the DOEs results indicated that the optimum setting was approx. (44) degree tilt angle and (42) cm cooling length with particle size (30.5) μm
The Cross-Rolling (CR) process is a severe plastic deformation technique that was used to roll aluminum alloy 6061. However, this process is accompanied by many disadvantages, such as spring back due to elastic recovery. This research aims to investigate the effect of cross-rolling on the spring back phenomenon by examining the main parameters that affect the forming process. Two different routes of cross-rolling were used: the first route, called two-step cross-rolling (TSCR), and the second, multi-step cross-rolling (MSCR), were employed to achieve high deformation and superior mechanical properties. The samples were bent using the V-bending process at three different speeds (5, 10, and 15 mm/min). The results showed that the rolling route and the change in cutting direction led to increased plastic deformation, thus increasing the spring-back factor. The type of route and cutting direction significantly impacted both the maximum load and the springback results.
Lean is a powerful process improvement strategy that is widely used to improve different processes. In this Paper, lean manufacturing as process improvement strategy is employed throughout relative tools and techniques as VSM, 5S, and standard work. These tools and techniques are employed to identify measure and evaluate processes. Job shop production of General Company for hydraulic industries, with focus on Damper and Tasks Factory (DTF) is tested as a case study for the two most customer demanded rear dampers of Samaned and Nissan. Data analysis shows different issues Work-In-Process (WIP) issues causing under/ over and production discrepancy. Improvements are introduced throughout WIP developments and 5S techniques. Results show that these developments may result in reduction of 65% WIP waiting time for Nissan and 58% of Samaned rear dampers. An increase in Overall Work Efficiency (OWE) could result in by 10% for Nissan, and 2% for Samaned dampers While 5S may result in improvements by 50% production processes and 43% assembly processes for Set in order , and by 33% in both production and assembly processes for standardize. Data where analyzed and further results are generated using software's are; Minitab Version 17, Quality Companion Version 3, and Edraw-Max Version 7.
The quality of the built environment could highly impact our state of wellbeing, by affecting our stress and exposure within the building environment. Scientific studies linked stress to depression, diabetes, obesity, and cardiac disease. Hospitals considered as stressful places due to their inconvenient experiences. The theory of Salutogenic design aims to reduce stress through the implementation of an interdisciplinary design study to enhance the sense of coherence ( SOC) for any individual to be able to adapt himself to the overall life challenges. Salutogenic defines several factors which can affect an individual’s state of well-being in any space. This research limited on two of these design factors (daylight, colour) within three selected hospital through a critical methodology using a sample questionnaire of 15 questions headed to 90 from all three hospitals. the second part of the methodology using a Light-meter device for calculating the amount of Lux in actual hospital conditions, the third part of research methodology is a simulation program (Ecotect) to have an adequate daylight calculation in the wards of all three hospitals as well as the lighting distribution with (daylight factor) to evaluate the efficiency of wards in Erbil city. The last part of the study is by a field investigation by the researcher for the implementation of Salutogenic Colours. through a critical methodology approach.The research results shows that wards of three hospitals has a poor natural daylight to penetrate the building, and hospitals depends mainly on artificial light which causes uncomfortability and inconsitnecy in treatment process. Patients prefrences are twords new colours such as turquoise, palepink, and blue rather than the tradtional colours used in Erbil governmental hospitals. using light meter as assessment tool to compare between the Ecotec Lux measurement and the actual condition of lighting in hospital. The evaluation of three Wards within hospitals shows clearly the un sufficiency of natural lighting which leads to needing of artificial daylight. And might delay the process of recovery. Ecotect calculates the most suitable design condition in any city and finds other suitable orientations for buildings.
Productivity improvement in the manufacturing industry of piping is a key challenge facing manufacturers in today's competitive markets. Improving productivity in the pipe manufacturing companies by implementing manufacturing principles that utilize simulation modeling was the purpose of this study. To improve productivity, an approach that focuses on the workstations and workforces process was suggested. The suggested approach’s goal was to increase productivity by providing customer prerequisites and leaving some products for other customers in the store. Based on the data has been gathered from the company of steel pipes, Bansal Ispat Tubes Private Limited in India, a simulation model was utilized to enhance its performance of operational. The investigation methodology consists of a simulation model, acceptable distribution, and data investigation. By simulating individual workstations and evaluating all relevant processes according to the data collected, the simulation model was built. Actual employment data were gathered from the line of manufacturing and supervisory workers, with observations carried out throughout the process of manufacturing. The used method involves videotaping of the process and interviewing workers using a video-camera. The superior continuous distributions were picked to fulfill a convenient statistical model. The results could be helps to ameliorate the manufacturing industry productivity. Furthermore, the outcomes could assist to solve the problems of scheduling in pipe manufacturing "simulating and modeling" which reveals active ways in enhancing pipe manufacturing productivity. Consequently, the findings might support well competition among companies.
The status of the infrastructure of the transport system and then mobility in the governorate of Anbar is deplorable. Therefore, it requires two types of solutions in two phases. This study concerned with the first phase, which is represented by solving the problem of the inadequacy infrastructure in terms of availability between the cities, and work to develop it toward being maximally connected. So, generally speaking this study aimed to facilitate mobility through this network, by improving the accessibility in term of connectivity. The analysis process in this study, have twin objectives: first, to determine how much new linkages we need for our network to be maximally connected as a first stage? Second, Building a legislative framework lends the weight for decision makers in transport agency to take tough decision built up on ranking the new proposed linkages according to their relative values in providing access to the network, and the increment in comparable nodal accessibility due to the new additions. So, there is need for more sensible decisions based on more accurate analysis for deciding the optimum priorities for the new linkages to take place in the stage of development implementation via legislative framework. Therefore, the analysis will deal with topological characteristics for a number of aspects by expressing the simple graph of the network in a matrix format. These aspects are simulated and measured through the matrices powering process and the principles of graph theory. However, in addition to reducing the time the vehicles stays on the road, the study results will assist to divert a large proportion of the traffic volumes concurrently with the implementation process, and this in turn will pave the way to precede the solution of the second phase inside the cities. Not to mention, the legislative framework will bases for the financial framework of the transport agency. Keywords: infrastructure inadequacy& development, accessibility and connectivity, graph theory, matrix representation &powering, new linkage, nodal accessibility , relative value ,optimum priorities (ranking) and Decision making(legislation).
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.
Is the refrigerant of the important factors affecting the cutting process as the use of fluids and in different proportions with water used in the cutting process has a clear influence on both the roughness of the surface of the metal to be used and the age of many because of that importance was the use of neural networks to predict the impact of the proportion of mixtures of different and find the best rate of mixing terms of access to the best surface roughness and longer life for many
Utilizing of subsurface water retention technology is a modern technique to retain and save the application water for sustainability of agricultural production through scheduling and management the irrigation processes. The goal of this paper is to evaluate the effect of the supplementary irrigation and rainfed water on improvement of economic water productivity for winter wheat. The experiment was conducted in open field, within Joeybeh Township, located in east of the Ramadi City, in Anbar Province, for the growing season 2018-2019. Two plots were used for comparison process, the first plot where membrane trough below the root depth was installed and supplementary irrigation system was conducted beside the rainfed water and according to scheduling the irrigation process as checkbook method. While in second plot, the membrane trough was installed and only rainfed water was depend on. Cultivated date of winter wheat was December, 20th, 2018, and the harvest date was May, 10th, 2019. The obtained result was showed that the crop yield and economic water productivity from the first plot and the second plot were equaled to 0.52 kg/m2 and 0.35 kg/m2, and 930 ID/m3 and 800 ID/m3, respectively. The increasing value of crop yield and economic water productivity in the first plot was more than that in the second plot by 49 % and 16 %, respectively. The benefits of applying supplementary irrigation system with installing the new techniques of retaining the applied water were sufficient in improvement the crop yield and accordingly improved value of the economic water productivity.
Better understanding the innovative process of renewable energy technologies is important for tackling climate change. Concentrated solar power (CSP) is a method of electric generation fueled by the heat of the sun, an endless source of clean, free energy. Commercially viable and quickly expanding, this type of solar technology requires strong, direct solar radiation and is primarily used as a large, centralized source of power for utilities. This study has focused on the feasibility of improving concentrating solar power (CSP) plant efficiency, by manufacturing a diminished prototype. Three states were studied, coloring the central target with a selective black color, fixing a reflector with arc form behind the target, and using these two changes together. The results showed an improvement in the thermal storage varied form month to month. The maximum stored energy was gained at August with increments about 56.1%, 58.63%, 62.23 and 64.69% for ordinary target, black painting, using reflector alone and black target with reflector together, respectively compared with stored energy for March.
This study aims to investigate the impact of various construction methods on labor productivity in Iraq, focusing on traditional, prefabricated steel structures, precast concrete, and mechanical or self-build construction techniques. The research employs a descriptive-analytical methodology, utilizing a structured survey distributed to 200 participants from different construction industry sectors, including engineers, contractors, and field workers. The survey examines key indicators of labor productivity, such as task completion speed, work quality, labor costs, safety, and project cost.The findings reveal significant differences in labor productivity across the construction methods. Traditional construction methods moderately impacted task completion speed and work quality but were less efficient in terms of cost reduction and safety. On the other hand, prefabricated and precast concrete methods demonstrated improvements in work quality, safety, and cost efficiency, although with some limitations regarding flexibility. Steel structures offered enhanced durability and faster construction times, while mechanical and self-build methods utilizing automation significantly reduced labor costs and accelerated the construction process.Based on these results, the study recommends incorporating modern construction methods, such as prefabricated and mechanical techniques, to improve overall productivity in the Iraqi construction sector. Additionally, it emphasizes the importance of training and adapting to these advanced methods to ensure long-term efficiency, safety, and cost-effectiveness in construction projects.
In this paper, a proposed structure was suggested by replacing the blocks of the fast Haar Wavelet Transform (WT) with a two dimensional wavelet transform at the transmitter and the receiver sides in the Orthogonal Frequency Division Multiplexing (OFDM) model. This can be done by converting a 1-Dimensional vector into a 2-Dimensional matrix and process it by 2-Dimensional Wavelet Transform (2D-WT). The proposed method was applied on the OFDM in Additive White Gaussian Noise (AWGN) and flat fading channel. It was concluded that the proposed method gives much better Bit Error Rate (BER) performance than the conventional OFDM model based on WT. The simulation results showed that the proposd structure outperforms the other scheme in the carried tests at the AWGN and flat fading channels.
The antenna is a Modified Broadband Butterfly Antenna (MBBA). The technical parameters of such systems are heavily influenced by the qualities of the antenna feed devices. The aperture theory of antennas uses the representation of the radiation field of the antenna as a superposition of the fields of elementary sources, characterized by their type and amplitude-phase spatial distribution. The radiation field of an antenna of finite dimensions is a superposition of inhomogeneous spherical waves emitted by the antenna elements. This paper is primarily the study process, Radiation models were calculated using the model of the cavity plates, Simple Green model, and the strict commercial Electromagnetic Simulator. The modified active rectangular patches with the Gann diode were combined into arrays of E and H plane. Calculated and measured results for these two active arrays the beam scanning, the possibilities have been demonstrated for both arrays. The results of an electrodynamics numerical simulation were obtained. Broadband and multiband radio systems have already found widespread practical applications by utilizing basic antenna parameters and characteristics.
The purposes of planning for housing and solve the housing problem of the most important topics in studies of housing also it is one of the topics broad and complex, and that the planned housing in accordance with the cost and social benefit is the solution to reduce the heights fantasy of the costs of housing. Also its negative effects on the process of housing where most of Iraq's society of the middle class is needed to adequate housing with income, especially if we consider that there is a deficit of housing dramatically in Iraq. Which is estimated at more than three million housing units and offset by a significant decrease in the rates of housing construction, also which are led to the worsening problem of housing in the country, especially those with low income, so it requires the parties responsible speed up the adoption of the strategy to solve the problem of housing in the country adopt the principle of the establishment of residential low-cost through the adoption of residential buildings, multistorey (3-4) stories as characterized by the buildings of the densities of housing appropriate of effective use with economic land and reduce the costs of housing to meet the large deficit and demand residentialdemand. In order to reach the desired goal has been studied and the reality of the housing in Ramadi in the, Ta'meem, 5 km and the 7 km areas and limited the problems of constraints related with planning housing also its components as well as access to some of the experiences of countries in planning, housing and solving the housing crisis within finding the alternatives to some traditional building materials with finding teams cost whenusingthesealternatives. Also supports research field study of three residential compounds, which aims at evaluating the appropriateness of such style housing and how to achieve social benefits and meet the standards of planning and design proposed in the scheme of public housing in Iraq which have been using the method (analysis of cost - benefit) for the trade-off to choose the best alternative of residential complexes three (and low cost, Ta'meem, the 7 km), which achieves less expensive and better utility.
CAPTCHA, which stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart, is a commonly employed security measure to distinguish between humans and computers. The Turing Test, designed to guarantee network security, is the foundation of this security technique. Usability is a crucial concern that can prevent human users from engaging in laborious and time-consuming tasks. When designing CAPTCHA, security and usability must be addressed simultaneously. When designing CAPTCHA, it is crucial to address security and usability simultaneously. A concerted effort is required to protect online data and guarantee privacy and security. The personal information of Internet users remains susceptible to theft. This study uses an information extraction technique called CAPTCHA to investigate the hazards associated with violating user privacy. It is a highly harmful process due to hacking, theft, unauthorized reuse, and the breach of user information. This study proposes a privacy preservation system employing concurrent encryption techniques, multilateral security computing, and zero-knowledge proof. The objective is to create a system that allows for uncomplicated and secure puzzle-solving using dice gas. CAPTCHA limits access to users' information. In the overview and application of evidentiary measurable methods, we can draw significant conclusions about the more extensive client group's discernments and encounters with CAPTCHA as a privacy-preserving component.
The reliability of water supply system is a critical factor in the development and the ongoing capability to succeed in life and people's health. Determining of its, with high certainty, for performance of water supply system is developed to ensure the sustainability of system. Reliability (Re) plays a great role in evaluation of system sustainability. The probability approaches have been used to evaluate the reliability problems of systems. The probability approach is failed to address the problems of reliability evaluation that comes by subjectivity, human inputs and lack of history data. This research proposed two models; I) traditional model: fuzzy reliability measure suggested by Duckstein and Shresthaand then developed by El-Baroudy; and II) developed model: fuzzy reliability-vulnerability model. The two models implemented and evaluation of water supply system by using two hypothetical systems (G and H). System (G) consists of a single pump and System (H) consists of a two parallel pumps. Triangular and trapezoidal membership functions (MFs) are used to investigate of the reliability measure to the form of the membership function. The results agree with expectations that the reliability of parallel component system {ReH (0.53)} is higher than the reliability of single component system {ReG (0.47)}. Moreover, the result by using fuzzy set reduces the effect of subjectively in process of decision-making (DM). The fuzzy reliability vulnerability is able to handle different fuzzy representations and different operation environment of system
The standard concrete mixing procedures indicate that during concrete mixing process, it is recommended to use fully saturated- dry surface course aggregates (FSDCA). It is clear that the exact application of this rule will produce a concrete of a good quality. But in practice, course aggregates are exposed to weather changes. This actual situation will lead to dry the course aggregates in summer and to over wet it during winter. To investigate the effect of using different moisture content course aggregates on concrete product in work site an experimental program had been done. This program consists of testing 54 concrete samples (27 cube +27 prism). The samples were divided into three groups (a, b, and c). The second group (b) was a concrete mix containing dry aggregates, while the third group (c) contained over wet aggregates and the first group (a) was the basic standard mix using (FSDCA). One third of the samples were tested in the age of 7 days, while the other third was tested in the age of 14 days and the rest after 28 days. Test results show that there are reduction in compression and flexural strengths of concrete due to the use of different moisture content course aggregates. Finally, new recommendations were concluded to be used in practice to overcome the mentioned repetitive error and to be more close to the theoretical recommendations in order to get better concrete properties.
Milling includes a variety of different tasks and tools, ranging from small individual pieces to large, powerful group processes. It is one of the most commonly used techniques for producing custom parts with exact tolerances. Surface roughness of machined parts has a significant impact on the finished item's quality, which may have an impact on its tolerance and performance. This paper studies the prediction of the values of surface roughness of low-carbon steel AISI 1015 in milling operations. Three different machining parameters with nine variable samples are selected to investigate the resultant surface roughness of the AISI 1015 low-carbon steel samples, including different spindle speeds, feed rates, and depths of cut. The results revealed that the feed rate of 100 mm/min at a spindle speed of 930 rpm and a depth of 1.5 mm produced the lowest surface roughness (Ra) value of 1.170 µm, while the feed rate of 300 mm/min at a spindle speed of 1100 rpm produced the greatest surface roughness value of 2.605.
Heat exchangers are considered essential parts in many industrial applications. The construction process for heat exchangers is completely complex because accurate measurements of the penalty of pressure-drop and the rate of heat transfer are needed. Designing a compact heat exchanger with a high heat transfer rate, while utilizing the least amount of pumping power, is the main design challenge. The most recent investigations (including experimental results, numerical models, and analytical solutions) in the field of circular tube heat exchangers in general, and twisted tapes and wire coils in particular, are covered in this review article, which has more than 90 references. The enhancement techniques in heat exchangers tubes can generally be separated into three groups: active, passive, and hybrid (compound) approaches. This article reviews the literature on advancements made in passive enhancement approaches, with a specific focus on two types of passive promoters that employ twisted tapes and wire coils. The main contribution of this research is to highlight the behavior and structure of fluid flow and the heat transfer features for the twisted tapes and the wire coils. It also explains how these passive promoters can be used in circular tube heat exchangers to improve hydrothermal performance. Where, the installation of wire coils and twisted tapes considerably alters the flow pattern and aids in the improvement of heat transfer. Where, comprehending the behavior of fluid flow is crucial and contributes to the enhancement of heat transfer. Twisted tapes are less effective in turbulent flow than wire coils because they obstruct the flow, which results in a significant pressure reduction. When it comes to turbulent flow, the thermohydraulic performance of twisted tapes is lower to that of wire coils.
Designing large structures like dams requires carefully selecting various geometric, hydraulic, and structural characteristics. The required structural design and performance criteria are considered when selecting these characteristics. In order to find the best solution, a variety of restrictions must simultaneously be carefully taken into account. This study presents an effective method for determining the optimal shape design for concrete buttress dams. The research was divided into two crucial phases. The dam's initial design and subsequent modeling were mostly done using DIANA FEA and traditional design and stability analysis. After that, a genetic algorithm was used on the MATLAB platform to control optimizing the dam's shape. Three design factors were used in this phase to alter the goal function and to reduce the amount of Concrete used, which decreased project costs. These variables covered three areas of the buttress's cross-section. Two important limitations were scrutinized during this optimization process: establishing a safety margin against overtopping and preventing sliding. The analysis included a detailed assessment of Shear friction stability to complete a thorough stability study. The optimization efforts had a spectacular result, resulting in a significant 52.365% reduction in the total volume of Concrete used, dropping from 19147.5 cubic meters to 9122.55 cubic meters. This decrease was made possible by reducing three distinct components (X1, X2, X3), with respective proportions of 37.5%, 13.33%, and 30%, including two segments related to the buttress and the final segment linked (slab) to the strip footing.
In this study, yttrium and aluminum were simultaneously co-deposited by diffusion into austenitic stainless steel (AISI 316L) substrates, by a single-step pack cementation process. Cyclic oxidation tests were conducted on the aluminide coating and on the yttrium modified aluminide coating of stainless steel in air under atmospheric pressure at temperatures 700 C° and 800 C° for 100h at 10h cyclic. Optical metallography and X-ray diffraction (XRD) techniques were used to characterize the changes in scale morphology and to identify the phases and oxidation products. The yttrium modified aluminde coating showed very good cyclic oxidation resistance compared to aluminide coating
In recent years, the elastomer forming technique has found acceptance on the shop floor and is used increasingly as a pressure- transmitting medium for various metal-forming operations. This is due mainly to the introduction of a new range of materials and of new concepts in tooling, which have served to kindle industrial interest in the process. The purpose of this paper is to study the sheet formability with compressible die (natural rubber). The forming was occurred using hemi-spherical punch and rubber die. Experimental tests were used to know the mechanical properties for rubber and sheet materials which were brass and aluminum. After that several forming processes were prepared with a 58 mm diameter steel ball as a punch to form 0.5 thickness brass and aluminum dishes with different diameters (15-40 mm). Force-stroke history was plotted through forming to find the stiffness of formed plate with rubber die and later to compare this parameter for different diameters. Wrinkling and springback were pointed for the formed dishes. It was found that the stiffness of the formed dish increases with diameter until reaching to the diameter at which wrinkling will takes place (about 33 mm for aluminum and 28mm for brass), and then the stiffness will decreases with diameter above this value. It was found that the springback ratio (ratio of final high to the stroke) was increased with diameter until wrinkling takes place, and this ratio is greater for aluminum than that for brass. The results show that it is able to use natural rubber as a die for sheet metal forming with limitation of using small sheet thickness
In this article, an experimental study of the single-pass hybrid (PV/T) collector is conducted in the climatic conditions of Fallujah city, where the experimental results are compared with a previous research to validate the results. The effect of changing the angle of inclination of the hybrid collector (PV/T) and its effect on the electrical power in the range (20°-50°) is studied. The optimum angle of the collector is found to be 30°, which gives a maximum electrical power of 58.8 W at average solar radiation of 734.35 W/m2. In another experimental study with different air flow rates ranged from 0.04 kg/s to 0163 kg/s, where it is found that the maximum electrical power of 57.66 W at an air flow rate of 0.135 kg/s, while the maximum thermal efficiency reaches 33.53% at an air flow of 0.163 kg/s at average solar radiation of 786 W/m2.
Solar cells play a vital role in renewable energy systems, and ongoing research is dedicated to enhancing their power efficiency and longevity. Advancements in perovskite solar cells, particularly in power conversion efficiency (PCE), have shown significant progress, confirming its viability as a technology. Perovskite solar cells have achieved power conversion efficiency (PCE) levels of up to 25.5%, comparable to conventional photovoltaic technologies like silicon, gallium arsenide, and cadmium telluride. The substantial enhancement in power conversion efficiency figures over the last decade has shown a remarkable advancement in the efficiency of perovskite solar cells. This study examines the trajectory of perovskite solar cells in becoming economically feasible and generally embraced as a critical renewable energy technology. The advancement of flexible and wearable solar cells, together with miniature solar-powered sensors, has increased the efficiency of solar cell power production. Perovskite solar cells have shown a specific power of 23 W/g, much higher than traditional silicon or gallium arsenide solar cells. Further research is needed to address the challenges related to perovskite solar cells' stability and power conversion efficiency. Perovskite solar cells integrated with energy storage units have the potential to enhance the overall efficiency of the system. This study discusses an approach to improve the efficiency of novel solar cells, specifically focusing on lead-free tin-based perovskite solar cells and tandem solar cells. The advancement of technology in thin films, such as hybrid nanocomposite thin films and quantum dot-sensitive solar cells, has the potential to improve the efficiency of solar cells. The primary outcome of this study is derived from the following inference: incorporating plasmatic nanostructures into thermal energy systems will enhance their efficiency and sustainability by integrating solar energy.
In this study, silicon and yttrium were simultaneously co-deposited by diffusion into austenitic stainless steel (AISI 316L) substrates, by a single-step pack cementation process. Cyclic oxidation tests were conducted on the siliconized coating and on the yttrium doped siliconized coating of stainless steel in CO2 atmospheric pressure at temperatures 800° C and 900° C for 100h at 10h cyclic. The results show that the initial weight gain is rapid and increased as the temperature increased. The oxidation resistance of the yttrium doped siliconized of stainless steels was significantly improved as compared with the siliconized stainless steels. The scale formed on coated stainless steel after oxidation in CO2 environment was thick and consisted of Y2O3, SiO2, Fe2O3 and chromium oxide. Optical metallography (LOM) and X-ray diffraction (XRD) were used to characterize the resulting coating and cyclic oxidation structures.
This new methodology utilizes Quality Function Deployment (QFD) with Analytic Hierarchical Process (AHP) together for improving product planning stage, hence, the product development, because this stage precedes the manufacturing stage and is regarded as an important stage in the product development. The proposed methodology consists of two models; namely: (1) Curent QFD Model. (2) Current AHP Model. It was applied practically to demonstrate the models' applicability and suitability, and develop liquid Gas Cylinder Valve produced at Al-Ikhaa General Company (IGC) for Mechanical Industries. "Thus it was possible to find out the critical and important specifications for improving product planning which should be considered in product development". These specifications have high ranking and Scaled Value Technical Ratings (SVTR) of over (50%). SVTR have values as follows: (1) (1.0000) for Pad (H1), then (2) (0.9270) for piston (H4), (3) (0.9195) for gasket (H12), (4) (0.8236) for safety valve (H6), (5) (0.8156) for sealing 1 (H5), (6) (0.6935) for sealing 2 (H9), (7) (0.5441) for installing the regulator with valve (H10) and (8) (0.5220) for spring2 (H7). When applying AHP method, various results were obtained. Based on the final score of Al-Ikhaa Company, where the highest defects value was (45%) was reported in the production processes. Also, values of maintenance dismantling 23%, Product assemblage 12% and maintenance assemblage 9% of the Product values.
The increase in traffic volumes at intersections is one of the important problems that makes difficulties in the traffic movement then leads to traffic congestion in these facilities.The objective of the present study is improvement the traffic operation of the selected intersection (Al-Zeoat intersection) in Al-Ramadi city by analysis and evaluation this intersection and using accepted solutions to improve the traffic operation of Al-Zeoat intersection under local exist conditions and present a best proposal to enhance the performance at the intersection.To achieve these objectives, the traffic volumes data collection and geometric layout for Al-Zeoat intersection that required for the traffic and geometrical analysis were gathered manually, while SIDRA traffic program is used for the requirements of traffic analysis process.
The most common type of abrasive water jet is known as a valuable and advanced non-traditional machining operation due to its no heat-affected zone, best in removing material, very environmentally friendly, and no mechanical stresses. This paper gives an idea about Abrasive water jets in terms of applications, advantages, and limitations. Also illustrates the influence of the parameters on the material removal rate. The effect of feed rate, pressure, and stand-off distance were worked, at three levels for material removal rate (MRR) to machining Aluminium alloy type-5083 by using a tool consisting of a mixture of 70% water and 30% abrasives of red garnet. The distance of the standoff has the most significant impact on the rate of material removal, which is subsequently followed by the feed rate and finally the pressure. The findings demonstrated that the Taguchi model is capable of making accurate predictions regarding the machining reactions, with a rate of material removal of 93.3%.
Responding quickly and economically to the diversification of customer needs has forced manufacturing companies adopting approaches to delivering low cost, high quality sustainable products based on finding a link between the design or the manufacturing processes and other key elements of sustainability; economic, environmental, and social. However, these approaches had limited success. The most likely reason for the lack of integration between the design and manufacturing stages of the product and complexity of addressing the above mentioned three key elements of sustainability due to existing of many variables in relation to design, manufacturing, locations, logistic operations and so on. Taking into account the required integration as well as the associated complexity of considering sustainability elements can lead to large space alternative solutions and it is more difficult to use only exact methods to the optimization of such problem. This paper presents a genetic algorithm (GA) approach aiming to optimize a high sustainability performance by designing a product and the corresponding manufacturing processes for that product. Process optimization is carried out in terms of the highest fitness function achieved where different objectives are to be optimized simultaneously. The proposed GA approach is applied to the industrial case example. The proposed approach can assist decision makers to help explain when justifying their decision on what are the best product design and its manufacturing processes to obtain high sustainability performance.
A new technique is presented by which lateral outflows of material , from an oblique impact collision between wax projectile and a rigid surface , are collected to form a high speed single jet. This jet has been shown to be capable of producing cavities in semi-infinite target of wax in a manner similar to that produced in a hypervelocity impact situation. The produced jet capability of penetration is found to be maximum at higher velocities of impact , lower values of standoff and with projectiles having angle of obliquity in the range (â=20-25o). A preliminary theoretical model is also presented in an attempt to describe the process of jet creation and jet characteristics. The present technique is proved to be promising in simulating penetration of semi-infinite targets by the impact of high speed jet .
The feasibility of using an Artificial Neural Network (ANN) for controlling time- varying dynamical system is presented. The direct adjusting of neural controller by direct adaptive control (DAC) is available, by using the error between output of plant and desired input. The finite recurrent back propagation (FRBP) is used in the learning process, because the ability of this method to capture the nonlinearly and overcome the problem of time varying system. Hybrid controller structure used in this paper, where the parameters of classical controller are adjusted with time at specified freezing points for time varying dynamical system, and summed the outputs of two controllers and enter to the plant, identify of system by ANN to get the optimal initial condition for neuro controller. A single channel for Spacecraft model is used as an example in this paper, satisfactory results are obtained, which explain the ability of recurrent neural network (RNN) to identify time varying dynamical system and overcome for all its problem and explain the ability of this structure of hybrid neuro controller to use with time varying dynamical system.
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.
In this study , Silicon and Aluminum with and without cerium were simultaneously co-deposited by diffusion into austenitic stainless steel (AISI 316L) substrates, by a single-step packcementation process. Cyclic hot corrosion tests were conducted on coated and uncoated austenitic stainless steel alloy with 50wt.% NaCl+50wt.%Na2So4 deposits at 750C° for 120h at 10h cycle. The results show that the hot corrosion resistance of both coated stainless steels, was significantly improved as compared with the uncoated steels. The scale formed on coated stainless steel after oxidation in mixture environment was consisted of NiAl2O4, NiFe2O4 and NiCr2O4. Optical metallography (LOM) and X-ray diffraction(XRD) was used to characterize the resulting coating and cyclic hot corrosion structures.
The field of image processing has several applications in our daily life. The image quality can be affected by a wide variety of deformations during image acquisition, transmission, compression, etc. Image compression is one of the applications where the quality of the image plays an important role since it can be used to evaluate the performance of various image compression techniques. Many image quality assessment metrics have been proposed. This paper proposes a new metric to assess the quality of compressed images. The principle idea of this metric is to estimate the amount of lost information during image compression process using three components: error magnitude, error location and error distribution. We denote this metric as MLD, which combines the objective assessment (error magnitude) and the subjective assessment (error location and error distribution). First, the metric is used to estimate the quality of compressed images using the JPEG algorithm as this is a standard lossy image compression technique. Then, the metric is used to estimate the quality of compressed images using other compression techniques. The results illustrate that the proposed quality metric is correlated with the subjective assessment better than other well-known objective quality metrics such as SSIM, MSE and PSNR. Moreover, using the proposed metric the JPEG2000 algorithm produces better quality results as compared to the JPEG algorithm especially for higher compression ratios
The dynamics of wind turbine has to be studied carefully to avoid unpredictable outputs and to make sure that consistent and efficient power is supplied according to the load requirements. There is a great and urgent necessity to increase the efforts in the development of the researches of the renewable energy to decrease the dependency on the conventional ones. The objective of this research is to make a contribution to the ongoing wind turbine research in the area of modeling, which is the first step required for the control and implementation of wind turbines. The wind turbine transfer function is derived and its performance has been established using the MATHLAB Software. This research provided a different approach to wind turbine modeling methodology. The results of this research may be used in another step for completing the control process of the wind turbine.
A Numerical study has been conducted to clarify the effect of the buoyancy forces on the thermal development through a horizontal annulus sector heated with constant surface temperature. The study includes the solution of governing equations for the flow and heat transfer of different sections along the channel. Theoretically these governing equations were reduced to four, which are continuity equation, radial and tangential momentum equations, axial momentum equation and vorticity equation in which the variables were the temperature, vorticity, stream function and axial velocity. These equations were reduced to dimensionless equations in which Rayleigh, Prandtl and Reynolds numbers were presented. They were numerically solved by using the marching process explicit finite difference method and Gauss elimination technique. Numerical results for annulus sector heated by constant surface temperature for different values of Rayleigh numbers and total sector angles and diameters ratio were obtained and represented by stream function contours and isotherms and circumferential distribution of local Nusselt number. Also the results include the values of friction factor and average Nusselt number for the pure forced convection. Comparisons are made between the computed results and the analytical or numerical results available in the literature, for all cases compared, satisfactory agreement is obtained. The results include a survey of annulus sector surface in many sites of channel flow, whereas it is apparent that the buoyancy force causes the secondary flow to behave non uniformly at the entrance and then the average heat transfer will increase with the increasing both of diameter ratio and total annulus sector angles. A correlation relationship is extracted to find an average change of Nusselt after the stability of the flow in the fully developed region for the studied ranges of annulus sector angles and diameters ratio.
Hilla cities center of province Babil is one of the most important cities in Iraq 100 km (62 mi) south of Baghdad .its relate the Governorate Baghdad with Governorates south Al-Thawra signalized intersection is one of the most important intersections in AL-Hilla city Being a major crossing point to the governorates of holy Karbala and Baghdad.The excessive traffic volumes, during the peak periods (at morning and evening), of vehicles that entering the intersection increase traffic density, reduce travel speed, increase travel time, and increase the delay values This paper aims to assess the traffic performance of Al-thawra signalized intersection in Babil city that is consistent with the existing conditions and intersection's geometric properties. For all approaches, video recording has been used to collect traffic volume data. These data are taken out of videos from Babil police cameras (department of communications and information systems)..The intersection was evaluated and analyzed using the SYNCHRO 10.0 software, and the best option was selected. The outcome of the evaluation process indicated that the intersection is operated at the level of service (LOS F) and with a control delay of 162.5 seconds.by recommending a variety of strategies, ranging from signal optimization to geometric enhancements. The suggestion of widening the pavement in the north-south direction was found to be the best solution. resulting in a decrease in vehicle delays from 162.2 seconds to 95.4 seconds and the level of service remains constant (LOS F) considered an acceptable and cost-effective solution to the intersection's problems.