Hydraulic actuators are one of the most viable choices due to their high power-to-weight ratio,low cost, robustness, fast response and great power supply. The present work focuses onbuilding an elevator prototype model simulates real hydraulic elevator. This model consists ofhydraulic parts (double-acting hydraulic cylinders, pump, valves, pipeline and filter) andelectronic parts (PLC, push-bottoms, relays and encoder). It is built with three floors in about300 cm height (total with the cylinder) to elevate a 30 kg payload and controlled by a PLCcontroller of (DELTA DVP-ES32) with 16 inputs and 16 outputs. The PLC receives input signals asorders from the operator as well as sensors and encoders. The PLC is programmed with WPSOFT2.46 Ladder diagram software to basically calling the elevator cabin through three locations andenabling its arrival at the desired floor. The cabin descent is achieved by using a proportionalcontrol valve which is controlled by the PLC. The cabin door is automatically opened and closedby DC motors. It is observed that, the application of this partnership between the PLC and theproportional valve in the build model helped to achieve excellent results in terms of systemcontrol and its efficiency, response, and smoothness.
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
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.
Serial Concatenation Convolutional Codes (SCCCs) encoder is built using a serial concatenation of two Recursive Systematic Convolutional (RSC) encoders, separated by an interleaver. These two RSC encoders depending on the trellis termination criteria are software implemented and the performance of each one of them is analyzed under different conditions and circumstances. The output data from the encoder are multiplied by an amplitude matrix (AM) at the transmitter side and the Inverse of Amplitude Matrix (IAM) at the receiver side. The reliability estimation, log-likelihood algebra, and soft channel outputs for Soft Output Viterbi Algorithm (SOVA) are examined. Then the modified Viterbi metric that incorporates a-priori information used for SOVA decoding is derived. A low memory implementation of the SOVA decoder is presented. The iterative SOVA for SCCCs is described with illustrative examples. The behavior of the SCCCs encoder-decoder scheme is tested under different circumstances with AM and without AM at the AWGN and Rayleigh fading channels with unlike frame sizes (FS) and constraint length (K). The results show that the performance of system with AM outperforms the other conventional system that worked without AM.
The thermal and acoustic isolation properties of unsaturated polyester composites reinforced by palm waste filler have been experimentally investigated. The composites have been prepared using hand lay-up technique with filler weight fraction of (0%, 3%, 5% and 7%). Three types of palm waste that (Date seed, old leaf bases and petiole) were ground and sieved separately to produce the filler with particle size ≤ 400µm. Thermal conductivity, thermal diffusivity, and specific heat capacity were examined using Hot Disk thermal analyses. The acoustic isolation property examined in a sound-insulated box. The experimental results show that the thermal conductivity and thermal diffusivity of the composite specimens reinforced by seed or old leaf bases filler increased with increasing the fillers weight fraction. While increasing the petiole filler decreased the thermal conductivity and thermal diffusivity by 19% and 40% respectively at 5% weight fraction as compared with a pure unsaturated polyester material. So, the composite reinforced with petiole filler has improved the thermal insulation properties. The composites samples reinforced with palm waste show higher sound absorption in compared to the pure unsaturated polyester material. The sound absorption properties of composite reinforced with 7% old leaf bases filler improved by 15% and 23% at low and high frequency respectively rather than of pure unsaturated polyester material.
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
Water treatment sludge (WTS) is a byproduct generated during the treatment of wastewater. In recent years, researchers have explored the potential of using WTS as a soil stabilizer to improve the geotechnical properties of soils. In this review, we will examine the current state of knowledge on the use of WTS for this purpose. The organic matter content of WTS is usually high and can range from 30% to 60%. The high organic matter content makes WTS a potential source of nutrients for plants, and it can also enhance soil structure and water retention. Another important consideration is the environmental impact of using WTS. The use of WTS can be an eco-friendly alternative to chemical stabilizers, which can have adverse effects on the environment. However, there are concerns about the potential for heavy metal contamination in WTS. To mitigate this risk, it is recommended to conduct thorough testing of WTS before using it as a soil stabilizer. Finally, the use of WTS as a soil stabilizer has the potential to improve the geotechnical properties of soils. However, it is essential to consider factors such as the type and dosage of WTS, the soil type, and the environmental impact before using it. Further research is also needed to explore the potential of using WTS in different soil types and environmental conditions.
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.
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.
A numerical investigation of mixed convection from a horizontal cylinder in a saturated porous medium is presented. The governing equations based on Darcy’s law are expressed in a body- fitted coordinate system and solved numerically by explicit method. The direction of the flow varies between the vertically up ward(assisting flow) and vertically downward(opposing flow). Results are presented for Reynolds number Re from 10 to 100 with Grashof numbers up to Gr =5Re. The Prandtl number was kept at a constant value of 0.7. results are presented for the streamlines and isotherms as well as the local and average Nusselt number at different values of governing parameters. Comparison with previous theoretical results show good agreement.
Traffic accidents and traffic delay have a negative impact on the mobility traffic flow due to their huge costs on the transport system. Thus one of the main primary aims for transport policy makers are reducing the negative effect of traffic accidents and traffic delay on the road network. In this study, fixed and random parameters Tobit models have been developed to model the accident rates from 20 intersections in Al-Karakh district in Baghdad City, Iraq. The safety significant of logarithm of annual average daily traffic, the percentage of heavy vehicles and the delay time for both major and minordirections for each intersection on the accident rates were evaluated. The main finding of this study shows that delay has an important effect on traffic accident rates of intersections. Regarding to the effect of other factors on traffic Accident rates, the result of the model shows that the logarithm of annual average daily flow, the percentage of heavy vehicles for both major and minor directions of the intersection are positively associated with more accident rates.
Reducing energy consumption and to ensure thermal comfort are two important considerations in designing an air conditioning system. The control strategy proposed is fuzzy logic controller (FLC).This paper describes the development of an algorithm for air condition control system based on fuzzy logic (FL) to provide the conditions necessary for comfort living inside a building.Simulation of the controlling air conditioning system, on which the strategy is adopted, was carried out based on MATLAB This system consists of two sensors for feedback control: one to monitor temperature and another one to monitor humidity. The controller i.e. FLC was developed to control the compressor motor speed and fan speed in order to maintain the room temperature at or close to the setpoint temperature.
In this paper, the hydraulic-thermal performance of a double-pipe heat exchanger equipped with 45°-helical ribs is numerically studied. The ribbed double-pipe heat exchanger is modelled using three heights (H = 0, 2.5, 3.75, 5 mm) of 45°-helical ribs. Two numbers (4-ribs and 8-ribs) of 45°-helical ribs are attached on the outer surface of the inner pipe of the counter-flow double-pipe heat exchanger and compared with a smooth double-pipe heat exchanger. Three-Dimensional computational fluid dynamics (CFD) model for a laminar forced annular flow is performed in order to study the characteristics of pressure drop and convective heat transfer. In addition, the influence of rib geometries and hydraulic flow behaviour on the thermal performance is system-atically considered in the evaluations. The annular cold flow is investigated with the range of Reynolds numbers from 100 to 1000, with three heights of ribs at the same width (W = 2 mm) and inclined angles of (θ = 45°).The results illustrate that the average Nusselt number and pressure drop increase with an in-creasing number of ribs, the height of ribs and Reynold number, while the friction factor decreas-es with increasing Reynolds numbers. The percentage of averaged Nusselt number enhancement for three rib heights (H = 2.5, 3.75 and 5 mm) at 4-ribs is (34%, 65% and 71%), respectively, While for 8-ribs the enhancement percentage is (48%, 87% and 133%) as compared with the smooth double-pipe heat exchanger at Re = 100. The best performance evaluation criteria of (PEC) at (8-ribs, and H = 5 mm) is 2.8 at Re = 750. The attached 45-helical ribs in the annulus path can generate kind of secondary flows, which enhance the fluid mixing operation between the hot surface of the annular gap and the cold fluid in the mid of the annulus, which lead to a high-temperature distribution. Increasing the height of 45°-helical ribs lead to an increase in the sur-face area subjecting to convective heat transfer.
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
This article presents a numerical study on forced convection of nanofluid flow in a two-dimensional channel with trapezoidal baffles. One baffle mounted on the top wall of channel and another mounted on the bottom wall of channel. The governing continuity, momentum and energy equations in body-fitted coordinates are iteratively solved using finite volume method and SIMPLE technique. In the current study, SiO2-water nanofluid with nanoparticles volume fraction range of 0- 0.04 and nanoparticles diameters of 30 nm is considered for Reynolds number ranging from 100 to 1000. The effect of baffles height and location, nanopar-ticles volume fraction and Reynolds number on the flow and thermal fields are investigated. It is found that the average Nusselt number as well as thermal hydraulic performance increases with increasing nanopartiles volume fraction and baffle height but accompanied by increases the pressure drop. The results also show that the best thermal- hydraulic performance is obtained at baffle height of 0.3 mm, locations of baffles at upper and lower walls of 10 and 15 mm, respectively, and nanoparticles volume fraction of 0.04 over the ranges of Reynolds number.
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.
This study aims to investigate the durability properties and microstructural changes of self-compacting concrete (SCC) incorporating waste polyethylene terephthalate (PET) as fibers and as fine aggregate replacement. This is after exposed to saline environment (Alkalies, Sulphates, and Chlorides). PET effect into two forms was also evaluated for routine rheological properties of SCC and mechanical strength before and after exposure to sulphate salt. Five proportions of each form of PET incorporation in SCC mixtures were utilized. The volume fractions considered for PET as fibers were (0.25, 0.5, 0.75, 1.0, and 1.25)% by volume, with aspect ratio of 28%, and (2, 4, 6, 8, and 10)% by volume for fine aggregate replacements. Results indicated that the inclusion of PET adversely affected fresh propertis especially high proportions of PET as fine aggregate. Alkali silica reaction (ASR) outcomes illustrated an enhancement in the mix containing PET fibers, while fine-PET mix was slightly enhanced. Magnesium sulphate reduced mass and compressive strength of all mixes in percentages ranging from (0.18-0.90) % for mass loss and from (0.47-55.13) % for compressive strength loss. Ultrasonic pulse velocity (UPV) and dynamic modulus of elasticity (Ed) increased due to the sulphate impact except for M0.5 and M10 which decreased in both tests. Chloride's theoretical and modelled results illustrated higher diffusion coefficients and lower surface chloride content of fiber-PET mixes as compared to fine-PET mixes. The predicted SCC cover depths for fiber-PET mixes were lower than those predicted for fine-PET mixes for 20 and 50 years of service life design.
Natural convection heat transfer in two-dimensional region formed by constant heat flux horizontal flat tube concentrically located in cooled horizontal cylinder studied numerically. The model solved using the FLUENT CFD package. The numerical simulations covered a range of hydraulic radius ratio (5, 7.5, and 10) at orientation angles from (0o up to 90o). The results showed that the average Nusselt number increases with hydraulic radius ratio, orientation angles and Rayleigh number. As well as enhancement ratio for Nusselt number at orientation angle 90o and hydraulic radius ratio 7.5 equal 24.87%. Both the fluid flow and heat transfer characteristics for different cases are illustrated velocity vectors and temperature contours that obtained from the CFD code. The results for the average Nusselt numbers are compared with previous works and show good agreement.
This study focuses on improving the thermal comfort in Mosques in Iraq. Omar bin Abdul Aziz Mosque in Baghdad is taken as a case study. In general, the weather in Baghdad is hot- dry climate during the summer. the study was conducted at the time of noon prayer on Friday where the maximum number of people can be obtained inside the Mosque about 500 worshipers and severe environmental conditions. Numerical methods (CFD) are used for the simulation utilizing the package of ANSYS (FLUENT V. 18). As the results depending on the number of elements, 4 millions elements are used for dividing the physical domain. Thermal comfort was assessed by finding the values of the predicted mean vote (PMV), predicted percentage of dissatisfied (PPD), and ASHRAE standard-55. The adaptive redistribution of the air conditioning device strategy at five cases is used to obtain the best thermal comfort. Moreover, changing the angle of air intake of space by changing the angle inclination of the access blade at three different angles of 0o, 7.5o and 15o degree, and studying its effect on the thermal comfort in breathing level. The four case is the best in terms of thermal comfort when the angle of intake air at 0o.when the PMV was 0.35 and PPD is 7.5, which is lower than the original state. The improving percentage of PPD is 10 % and PMV 14 %.
In this work, a new key exchange protocol for IP-based mobile networks is introduced. This protocol is called KEPSOM (Key Exchange Protocol Supporting Mobility and Multihoming). The goals of designing KEPSOM are to develop key exchange protocol proposal characterized by its secrecy, simplicity, efficiency, resistivity, and its ability to support mobility and multihoming. The protocol requires only two roundtrips. The design limits the private information revealed by the initiator. An old security association (SA) can be replaced with a new one by rekeying without the need of restarting the protocol with a new session. On the other hand, the changes in IP address due to mobility or multihoming need not to restart the protocol with a new SA session. The proposed protocol can also support key exchange in hybrid wireless network, in which the mobile node can operate in both Ad Hoc and Base Station-oriented wireless network environments using different transmission modes. KEPSOM has been analyzed and proven secure. Several tests have been done to measure and evaluate the performance of the protocol. In these tests, it is found that the required time for rekeying is about 27% of the total required time for exchanging the keys. And the required time to detect and update the change in IP address, which may occur due to mobility or multihoming, is less than 10% of the total required time to establish a new SA sessions.
The studying of the distribution of wetting patterns in soils having a stratified profile is of great importance due to the presence of this type of profile in abundance in agricultural lands, including greenhouses. Therefore, there was a need to develop a numerical program that predicts the dimensions of the wet area of the subsurface drip irrigation system under different operating conditions for purpose design and manage these systems properly to avoid water losses resulting from evaporation or deep penetration. The present study aims to develop a two-dimension model simulates the wetting pattern in stratified soils using (HYDRUS-2D) software and study the effect of soil hydraulic properties and different operating conditions on the progress of the wetness pattern and the interference pattern between two wetting fronts. Laboratory experiments were carried out for the system of subsurface drip irrigation in stratified soils that consisted of three layers (silty clay loam soil, loamy sand soil, and sand soil) arranged from bottom to up. Three different emitter flow rates 0.5, 1, and 2 l/h were tested, as well as three different initial moisture contents for each soil layer were considered. The interference pattern between two wetting fronts of two emitters with different spacing between emitters 30, 40, and 50 cm was studied. A numerical model was developed to guess the horizontal and vertical dimensions of the wetting zone for the single emitter and the pattern of interference between the two wetting fronts of two emitters. The predicted values obtained from the numerical model were compared with those obtained from laboratory experiments. Statistical analysis of the obtained data showed that the developed numerical model has a good ability to guess the dimensions of the wet pattern of the single and the two emitters and there were good agreements between the predicted and the experiments results and minimum values of RMSE ranged between 0. 5 and 3.6 were achieved.
TMF (thermomechanical fatigue) damage model devoted to prediction of the high temperature fatigue lifetime of navel copper alloy (C46400) , was proposed .This model was built on the basis of the stress –number of cycles curve responsible for damage due to interaction of high temperature and fatigue. This obtained prediction compared was very favorably with the cumulative experimental TMF results.
This research focuses on studying the impact of different sources of wastewater, such as do-mestic, industrial, agricultural, etc. upon groundwater. The swamp of contaminated water collec-tion within the Al-Anbar University area was taken as a case study for this research. This swamp has a pond that works as a collection basin for different sources of wastewater mainly domestic waste coming from leakage of contaminated water from the septic-tank of the residential com-plex of students. This contaminated water will leak over time within the folds of soil due to per-meability and the effect of land attraction and reach the levels of groundwater.The presence of polluted water near groundwater is an environmental hazard and harmful because this leakage water has different diseases and germs, which could pose a danger to human health. Different samples of these sources were taken from different places at different times and some physical, chemical, and biological tests were then conducted. Wastewaters characterization was also investigated in this study to make an assessment for water quality and find out a proper treatment method. Data obtained from this study show different levels of pollutants, which could highly affect groundwater quality. A proper and advanced treatment method was also proposed in this study, depending on the wastewater characterization results. The purpose of this research is wastewater treatment using the physical method with coagulation and Flocculation processes with local coagulants to reduce pollutants impact on groundwater.The results showed the addi-tion of alum at 35 mg/l increased the removal efficiency by 80.7% at the settling time of 60 min, and the addition of 35 mg/l of the lime increased the removal efficiency by 63.9% at the same settling time.It has been proven that the use of alum is more effective than lime for sedimenta-tion suspended matter. The optimum dosage and settling time are 20 mg/l and 60 min respec-tively.
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.
Prefabricated schools are educational structures of great significance and utility, especially given our country's current challenges. They expedite construction, reduce environmental impacts, and enhance educational activities with strong structural integrity and comfortable, flexible, and healthy design. A compelling comparison can be made with traditional concrete schools. With advancements in technology and information in engineering and the construction industry, Building Information Modeling (BIM) technology has emerged, playing a vital role in prefabricated concrete engineering through 3D modeling simulations.Numerous challenges are encountered, such as meeting client requirements, project delays, cost overruns, quality issues, stakeholder conflicts, labor shortages, safety concerns, increased change orders, material wastage, and project complexity. Developed countries utilize BIM to mitigate these challenges and profoundly improve the AEC industry's performance. BIM tools provide a comprehensive building visualization, empowering stakeholders to make informed decisions that ensure efficiency, sustainability, and cost savings. These features motivate engineers and contractors to rely on them as essential engineering applications.This research involves modeling a school building in the Revit program, studying work flow between Revit and ETABS program, and conducting a dynamic analysis of the model from Revit. It also emphasizes the benefits of prefabricated construction and BIM technology, facilitated by Revit. The study emphasizes how important it is to visualize the building's actual form before beginning the design and decision-making processes.in summery, this study provides the possibility of growth and application in the industrialization of the construction industry and raise the project's overall quality. The development of tools and plugins programmed to reduce interoperability problems between various software packages allows for integrating all design activities.
In this paper, turbulent forced convection of nanofluid flow in channel with isoscelestriangularbaffles is numerically investigated over Reynolds number ranges of 5000-10000.One baffle mounted on the bottom wall of channel and another mounted on the top wall.Al2O3-water nanofluid with nanoparticles volume fraction of 4% and nanoparticles diametersof 25 nm is used. The governing continuity, momentum and energy equations as well as thelow Reynolds number k-ε model of Launder and Sharma have been solved using finitevolume method. The effect of baffle height, baffle distance as well as Reynolds number onthe flow and thermal characteristics have been presented and discussed. It is found that theenhancement ratio of the average Nusselt number as well as the fraction factor increase withincreasing in the baffles height. It is also found that the enhancement ratio of the averageNusselt number increases as the distance of top baffle decrease. Furthermore, the bestthermal-hydraulic performance of channel with triangular baffles using nanofluid can beobtained at baffle height of 2.5 mm, distance of the top baffle of 40 mm and Reynoldsnumber of 5000.
Designing an integrated communications system with efficient features is important to researchers and designers. This paper deals with a review of the most important technologies and applications that combine solar cells and communication systems such as Li-Fi technology and its principle of operation, which is a wireless system in which the optical signal is used as a carrier signal as an alternative to the traditional radio frequencies used in Wi-Fi networks, where Li-Fi relies on LED to transmit data, and at high speeds that exceed Wi-Fi technology. Solar Power Satellite (SPS) technology where the satellite is placed in a geostationary orbit in the equatorial plane. As well as the application of photovoltaic solar cells in the SOLPLANT planar antenna, and the replacement of the radiating element of the antenna with a solar cell. The solar cell can transmit and receive electromagnetic signals as well as generate direct current and can be used as antennas either as a single solar cell or group cells and has wide applications in wireless, mobile, Bluetooth and satellite systems. The solar cell has also been applied in Micro strip antenna called Solan , where the solar cell antenna can be considered as a platform for many communication applications and can also be adopted as a radio frequency transmitter and receiver. As well as the design of many antennas integrated with solar cells and compatible with the 5G communication system , in addition to the presence of many applications that combined smart phones and solar cells. This study showed that these technologies and applications provided clean, safe, high-efficiency, high-speed, data-transferring communication systems with low cost.
This paper specifies a proposed improvement model of Data Encryption Standard (DES) which may be used to protect sensitive data. Protection of data during transmission may be necessary to maintain the confidentiality and integrity of the transformation represented by data. Instead of expansion step in each round which made by copying 16 bit from 32 bits data in each right side of the standard algorithm, the unused 8-bits as a key (sometimes it is used for error detection and correction purposes, or it is possible to generate an additional 8-bits with the 56-bits standard key) in the first starting round with the other 8-neglected bits from each of 16 round in the key algorithm will be used, and take the same locations of the expanded data. As a result, the complexity to cryptanalysis of the secured data has been increased. The proposed method was more active and reliable than standard conventional DES, where it can be switched to the system at any round for working with original DES algorithm, which means that an additional security has been added
The published studies about the water quality of Euphrates River in Iraq till now have been reviewed critically. The revision of the published researches depend upon several bases including the period of samples collection, the number of sampling stations, water samples collection method, the analytical techniques employed to measure and analyze the results. This critical study concluded that the need to follow a specific protocol in selection sampling sites, how the samples are collected, how samples are analyzed, and pay attention to quality assurance and quality control during sample collection, preservation and analytical procedures.
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.
This paper presents the experimental results of composite slabs under static and impact loading. Total of six specimens classified one specimen test under static loading and the remaining five were tests under impact dynamic loading with different parameters as type of connections and degree of interaction of composite slab. Low - velocity impact test was adopted by select the falling mass (4 kg) made from steel material and formed as ball shape without nose. The ball dropped freely from height of (2.4 m) and strikes the top of composite slab. The designed dimensions of specimens is (500×500×60 mm) as reinforced concrete slab that reinforced by mesh of (RBC) and the steel plate is (3 mm) in thickness. Deflection due to first crack is recorded, number of blows caused first crack and failure were counted. The test results showed that the welded stud connectors gives high strength capacity and resistance under static and impact dynamic loadings than other than type of connections, also, full interaction as degree of interaction is better than others
Modeling and simulation are indispensable when dealing with complex engineering systems. It makes it possible to do essential assessment before systems are built, Cantilever, which help alleviate the need for expensive experiments and it can provide support in all stages of a project from conceptual design, through commissioning and operation. This study deals with intelligent techniques modeling method for nonlinear response of uniformly loaded paddle. Two Intelligent techniques had been used (Redial Base Function Neural Network and Support Vector Machine). Firstly, the stress distributions and the vertical displacements of the designed cantilevers were simulated using (ANSYS v12.1) a nonlinear finite element program, incremental stages of the nonlinear finite element analysis were generated by using 25 schemes of built paddle Cantilevers with different thickness and uniform distributed loads. The Paddle Cantilever model has 2 NN; NN1 has 5 input nodes representing the uniform distributed load and paddle size, length, width and thickness, 8 nodes at hidden layer and one output node representing the maximum deflection response and NN2 has inputs nodes representing maximum deflection and paddle size, length, width and thickness and one output representing sensitivity (∆R/R). The result shows that of the nonlinear response based upon SVM modeling better than RBFNN on basis of time, accuracy and robustness, particularly when both has same input and output data.
In this paper, a proposed model based on phase matrix rotation was suggested to improve the performance of Multicarrier-Code Division Multiple Access (MC-CDMA) lies in Fast Fourier Transform (FFT) algorithm under the Additive White Gaussian Noise (AWGN) and frequency selective fading channel. This model is used to reduce the effect of multipath fading. The results extracted by a computer simulation for a single user, then it compared with the original technique for MC-CDMA based on FFT for both systems. As a result, it can be seen from the proposed technique that a high performance improvement was obtained over the conventional MC-CDMA, where the Bit Error Rate (BER) is widely reduced under different channel characteristics for frequency selective fading and the AWGN channel
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.
This research includes the study of bending strength for the polymer composite materials. The first of all, the hand lay-up technology is used to prepare slates of the composite materials, epoxy resin was used as matrix for the reinforced materials that consist of artificial powders (aluminum oxide and copper) for reinforcing. The slates made of composite materials for both volume fractions 20% and 40% from the reinforced materials; all these slates were cut into samples with measurement (10x 100 mm) in order to carry out the bending strength test for samples by using cantilever bending test for both volume fractions 20% and 40%. The results and laboratory examinations for these samples shows increase in the bending strength and modulus of elasticity for composite materials when the volume fraction increase from 20% to 40% for reinforced materials, and these values decrease when the samples were immersion in distilled water for (30) days.
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).
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.
The behaviour of multiple cracked cantilever composite beams is studied when subjected to moving periodic force. In this investigation a new model of multiple cracked composite beams under periodic moving load is solved. Three cracks are considered at different position of the beam for numerical solution. The results from experimental work compared to numerical solution. The multiple cracks are identified easily from the deflection graphs at different force speed. Influences of crack depth at different load speed are investigated
The convergence of cloud and edge computing in smart manufacturing offers significant potential for improving efficiency in Industry 4.0. However, task scheduling in this context remains a complex, multi-objective challenge. This study introduces a novel Cloud-Edge Smart Manufacturing Architecture (CESMA), leveraging a hybrid approach that integrates NSGA-II and the Improved Monarch Butterfly Optimization (IMBO) algorithms. The combination utilizes NSGA-II's global search and non-dominated solution capabilities with IMBO's fine-tuning and local optimization strengths to enhance task scheduling performance. Where CESMA combines the scalability and analytics power of cloud computing with edge-based real-time decision-making to address the dynamic demands of smart manufacturing. Through extensive simulations and experiments, the feasibility and effectiveness of CESMA are validated, showing improved task scheduling quality, resource utilization, and adaptability to changing conditions. This research establishes a robust platform for managing the complexities of task scheduling in cloud-edge environments, advancing intelligent manufacturing processes, and contributing to the integration of evolutionary algorithms for real-time industrial decision-making
In this work, a Fuzzy Model Reference Adaptive Controller FMRAC is presented for the speed control problem of a DC motor. The proposed controller is designed in two phases. In the first phase, the model reference input-output data is used to obtain the fuzzy rules. Then the effective rules are chosen to be used in the second phase. In the second phase, the obtained controller is applied in two conditions; the non fuzzy rules or adjusting the center of output membership functions. The simulation results shows a good speed motor tracking to the model reference in the word of the step response coefficients.
This research represents part of the current attempts to employ remote sensing data in the scopes of the civil engineering and the geotechnical engineering applications. There is great need to know the kinds of soil and their geotechnical properties, to create recent maps which have the capability and high flexibility to deal with them in digitizing way. Therefore GIS techniques are employed in the soil of area of study . By using ArcView software, a geographical database and information about soil chemical properties analysis have been registered and constructed digitally to represent the geotechnical soil characteristics maps . The work includes the digital image processing ( digital classification techniques) by using ERDAS, ver.,8.4 package, and classify the soil of study area by using the supervise and unsupervised techniques . The geotechnical maps by using GIS techniques depend on remote sensing data are the better to represent the ground truth regarding the characteristics of soil , in comparison with the traditional method, because they are easy way to produce, use, store and update, in addition they save in efforts, time and cost . The results of this study have shown that the soil of study area is gypsum where it ratio exceeded the allowable ratio ( 10.75 % ) for all samples . In addition the total Soluble Salts ratio and SO4 ratio high compared to allowable ratio (10 % , 5 %) respectively .
This research paper is an attempt to reuse plastic waste fibre resulting from plastic sections industry as an additive to concrete matrix. The relationship between fibre volume fraction and mechanical properties of concrete and re-inforced concrete tiles was investigated. Three volume fractions of fibre ( 0.5 % , 1 % and 1.5 % - by volume of concrete ) were used through the experi-mental program. Tests’ results proved a slight decrease in concrete compres-sive strength as plastic fibre was added compared with the reference mix. Flexural behaviour of concrete tiles was enhanced as adding fibres. Adding fibre to Concrete results in a negligible reduction in concrete density. Fibre with high volume fractions improved Splitting tensile strength compared to the reference mix.
This paper deals with a numerical investigation of natural convection of heat transfer in a horizontal eccentric annulus between a square outer enclosure and a heated circular inner cylinder. The governing equations are expressed by the term of the stream function-vorticity with dimensionless temperature. The body fitted coordinate system (BFC) was used to stretch over the physical domain of the presented problem. The Poission's equation of stream function is solved by successive over relaxation (SOR) method, while time marching technique was the best choice to solve both vorticity and energy equation.The results are presented for the streamlines and isotherms as well as the average Nusselt number at different eccentricities and angular positions. Comparison with previous theoretical results shows good agreement.
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.
Portland cement consists of major oxides which include CaO, SiO2, Al2O3 and Fe2O3 as well as minor oxides which include: SO3 , MgO, Na2O and K2O, the last two oxides are called alkalis oxides. The research aims to study the effect of alkalis oxide ( Na2O+ K2O) on some physical properties of ordinary Portland Iraqi cement (type I) and sulfate - resisting Portland Iraqi cement (type V) provided from (Taslooja Factory) are used in the experimental work. The physical properties of the two types above , which are used in the experimental work, are initial and final setting time, soundness and compressive strength at (3, 7 and 28)days. The results show that the values of physical properties of type I and type V increase when the alkalis percentage increases up to 0.6 percent, while the value of the physical properties of the two types of cement mentioned above begins to reduce even when the percentage of alkalis still increases. Through the use of the ordinary Portland cement (type I) and the sulfate resisting Portland cement (type V), it is found that there is a little difference in the value of the physical properties.
Indeed, there are many hydrology variables influence on the operating of dam and reservoir system. Thus, modelling of dam operation is a complicated issue due to the nonlinearity of such hydrological parameters. Hence, the identification of a modern model with a high capacity to cope with the operation of the dam is extremely important. The current research introduced good an optimization algorithm, namely Genetic Algorithm (GA) to find best operation rules. The main aim of the suggested algorithm is to minimize the difference between irrigation demand and water release value. The developed algorithm was applied to find operation rules for Timah Tasoh Dam, Malaysia. This research used significant evaluation indexes to examine the algorithms' performance. The results indicated that the GA method achieved low Vulnerability, high Resilience and Reliability. It has been demonstrated that the GA method will be a promising tool in dealing with the problem of dam operation.
The Digital control systems for substations have been installed in different areas of Iraq in the recent years. Most of these techniques used a Supervisory Control And Data Acquisition (SCADA) with Remote Terminal Unit (RTU) for monitoring the metering devices for incoming and outgoing feeders, while the other system used a Programmable Logic Control (PLC) technique for controlling and monitoring the system inside substations by professional engineers. A practical monitoring system of SCADA with RTU has been introduced in this paper for Falluja substation. There are 3 devices of RTUs are used to collect data from ION 6200 devices installed inside incoming and outgoing panels for low Voltage (LV 380V), 33KV and 11KV, then the data from each RTU will be send to the SCADA (main Computer) via special router, the SCADA system used ION enterprise software supplied by AREVA company in addition to all panels which supplied by the same company. Many difficulties were appeared during the work, such as mistakes of IPs, setting parameters, selection of protocols, and matching of devices have solved until the normal work was obtained to the substation.
The impact resistances of concrete slabs have a different volume fraction replacement of waste plastic aggregate has been examined in this study as a fine aggregate as: 0% (reference), 10%, 20% and 30%. These tests include the splitting tensile, density, compressive strength. Also, the (ultrasonic pulse velocity tests) was carried out. Repeated falling mass was used in order to carry out the low-velocity impact test in which a 1300 gm steel ball was utilized. From a height of 2400mm, the ball falls freely on concrete panels of (500×500×50 mm) with a network of waste plastic aggregate. As per the results, a prominent development was seen in the mechanical properties for mixes involving polyethylene aggregate up to 20% as compared to the reference mix. A significant development was seen in low-velocity impact resistance of all mixes involving waste plastic fine aggregate as compared to reference mix. As per the results, the greater impact resistance at failure is offered by the mix with (20%) waste plastic aggregate by volume of sand than others. The reference mix increased by (712.5%).
Turbo codes have been deployed in many cutting-edge technologies because they can achieve very high coding gains. Turbo decoders deploy at least two Soft-Input-Soft-Out (SISO) decoders, which operate iteratively to incorporate their results to conclude the output. The soft outputs from the used constituent SISO decoders develop gradually along the iterations. This development is studied and analyzed in this work to understand the dynamics leading to the results. Histograms statistically group and visualize the soft results for further analysis and study. A method is proposed to evaluate the decoding performance based on the density of the values of the soft outputs within the histogram. Results show that the performance is inversely related to the ratio of the values of the soft outputs within the near-zero bins within the histogram. The proposed method can be deployed at the decoder to provide an early indication of the reception and whether it has the potential to be correctly decoded or not. This early decision can save the decoding resources.
The scientific paper examined the possibility of developing an advanced healthcare management system in Iraq through the use of Cisco Packet Tracer software. The article stated that the aforementioned software has the potential to speed up network management operations and reduce expenses incurred in maintenance and repair activities. In addition, the article explained several challenges that may arise during the implementation of the smart hospital management system, including providing the required technical expertise, infrastructure provisions, and procedural measures necessary to protect the confidentiality of patient and employee information. The study confirmed that implementing an intelligent hospital management system in Iraq has the potential to improve healthcare quality, mitigate medical errors, enhance employee communication, and reduce disturbances within the hospital setting. Furthermore, this intervention is expected to enhance the efficiency of resource and inventory management and increase patients' experience and satisfaction with healthcare services. The article concludes that achieving the desired results in implementing a smart hospital management system using Cisco Packet Tracer software depends on the collaborative contributions of employees, managers, and technical professionals. This initiative is expected to enhance the hospital's ability to provide medical services of exceptional quality and effectively meet the diverse needs of patients.
Using three-phase synchronous generators basic units in power plants, the main source for feeding alternating current. The electromagnetic force (e.m.f) given by these generators depend mainly on the number of pairs of poles in the Member excitement and speed of rotation cycles of the generator. Since the number of pairs of electrodes are part of the structural arrangement of generator will not change due to overload, but it will be the adoption of frequency only on the speed with which revolves where the generator. The power transformers are the heart's main power plants and power transmission and delivery to the consumer and based on the work of the converted electric depends on electromagnetic induction, so the performance of work directly related to the frequency in which they operate. It is through this research will be identified on the behavior of each of the born Synchronous and transferred electrical in the case of low frequency. This is done checks of laboratory and compared to examine the system simulation through the language of MATLAB has been done to change the frequency and noting the effect on each of the power factor, efficiency and organization of voltages for each of the converted and born Synchronous and show results in the form of charts.
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.
Numerical solutions are presented for mixed convection from an array of circular cylinders embed in a saturated porous medium. The cylinders are at constant temperature(isothermal) and arranged in a staggered tube bank. Both aiding and opposing flow conditions are considered. Numerical calculations using finite difference method with body-fitted coordinates have covered a wide range of governing parameters(i.e.,10 ،ـ Re ،ـ 100, 0 ،ـ Gr ،ـ 400 and Pr = 0.7). Results are presented for streamline, isotherms and the local and the average Nusselt number at different values of the governing parameters. The present results are compared with previous theoretical results and show good agreement
The goal of the current investigation is to construct an artificial neural network (ANN) to estimate the ultimate capacity of the composite columns consisting of a rectangular steel tube filled with concrete (RSTFC) under concentric loads. The experimental results of (222) samples collected from previous researches were used in constructing the proposed network. Totally (45) specimens were randomly chosen for network testing while the remaining (177) speci-mens were used to train the network. The information used to create the ANN model is ar-ranged into (6) variables represents the different dimensions and properties of the RSTFC col-umns. Based on the input information, a formulated network was used to estimate the columns' ultimate capacity. Results obtained from the formulated network, available laboratory tests, and Eurocode 4 and AISC equations were compared. The network values were closer to the laboratory values than the calculated values according to the specifications of the mentioned codes. It has been shown that the formulated ANN model has a high ability to estimate the RCFST ultimate capacity under concentric loads
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.
This study aims to improve different properties of sustainable self-compacting concrete SCC containing treated and modified polyethylene terephthalate PET fibers. For this purpose, gamma ray surface treatment and geometric modification were utilized for the used PET fibers. Concrete fresh properties include slump flow, T500mm, L-box and sieve segregation while mechanical properties include compressive, split tensile strength, flexural strength, static modulus of elasticity and impact strength. Further, physical properties and related durability properties comprise dry density, ultrasonic pulse velocity, porosity and water absorption. The results obtained demonstrated that the treatment and the modification used for the PET fibers slightly reduced the fresh properties of produced sustainable SCC (slump flow, T500 mm, L-Box and sieve segregation). However, they were within the limits of the SCC specification as reported in EFNERC guidelines. Further, concrete hardened properties in terms of compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, impact strength, ultrasonic pulse velocity, decrease in the dry density, decrease in porosity and water absorption increased significantly.
In satellite communications with frequencies above 10GHz the major problems in radio-wave propagation is signal level attenuation caused by tropospheric scintillation, together with signal level attenuation by rain. There are several methods to measure the magnitude of scintillation. The equations of most of these methods do not include meteorological element. In meantime we can not measure the magnitude of scintillation with elevation angle 5¢ھ-10¢ھ. A prediction method is suggested to measure tropospheric scintillation on earth-space path. It would apply this method to standard atmosphere and we studied the effect of meteorological conditions, frequency, antenna diameter and elevation angle on the magnitude of scintillation.
The problem of the spread of landmines and their remnants of war in Iraq in general and in the province of AL-Basrah is one of the existing issues that did not find successful solutions and steps to eliminate them and minimize the adverse effects and damage caused by them on the human and material property. This research aims to identify the areas of contamination by landmines and war debris to reach a clear vision that facilitates the development of solutions by the competent authorities through the preparation of a geographic database and a spatial database. All data and maps are collected, digitize them, conduct a range of statistical and spatial analyzes possible, and produce thematic maps
This work presents a compact reconfigurable antenna based on fractal geometry. The investigation discusses the challenges of lower antenna gain and bandwidth, critical for efficient data propagation in 5G systems, particularly for low-profile devices. Its goal is to develop a small, multiband antenna capable of operating in all current and future 5G bands and improve bandwidth and gain for mm-wave and sub-6 GHz applications. The proposed design covers the sub-6 band (2.8, 3.9, 4, 6.2) GHz and the mm-wave band (24.4, 27.1, 28.5, 29.3, 30.6, 33.9, 34.6, 35.2, 38.8, 44.4, 45.1, 59.7, 61.5, 62.3, 65.2, 67.4 and 69.5) GHz with S11 less than -10 dB. A maximum gain of 12.8 dB and a radiation efficiency of 94% are achieved. A partial ground plane with a 50 Ω feed line is used in this design. The antenna is printed on a Roger RT 5880 substrate with a relative dielectric constant 2.2 with a total dimension of 35×32.5×0.8 mm³. The proposed design is simulated using CST software, ensuring accurate calculations and performance evaluation.
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.
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
This paper offers the linear analysis of the static behavior of two directional functionally graded(2D-FG) cylindrical panels under the effect of internal symmetric loads. The mechanicalproperties of the cylindrical panel are given to be changed simultaneously through the thicknessand longitudinal directions as a function to the volume fraction of the constituents by a simplepower-law distribution. Based on Sander’s first order shear deformation shell theory (FSDT), theequations of motion for (2D-FG) panels are derived using the principle of minimum totalpotential energy (MPE). The finite element method (FEM) as an effective numerical tool isutilized to solve the equations of motion. The model has been compared with those available inthe literature and it observed good correspondence. The influences of the material variationalong the thickness and longitudinal directions, geometrical parameters, boundary conditionsand load parameters on the panel deformation are studied in detail.
The Cooper-Harper rating of aircraft handling qualities has been adopted as a standard for measuring the performance of aircraft. In the present work, the tail plane design for satisfying longitudinal handling qualities has been investigated with different tail design for two flight conditions based on the Shomber and Gertsen method. Tail plane design is considered as the tail/wing area ratio. Parameters most affecting on the aircraft stability derivative is the tail/wing area ratio. The longitudinal handling qualities criteria were introduced in the mathematical contributions of stability derivative. This design technique has been applied to the Paris Jet; MS 760 Morane-Sualnier aircraft. The results show that when the tail/wing area ratio increases the aircraft stability derivative increases, the damping ratio and the natural frequency increases and the aircraft stability is improved. Three regions of flight conditions had been presented which are satisfactory, acceptable and unacceptable. The optimum tail/wing area ratio satisfying the longitudinal handling qualities and stability is (0.025KeywordsLongitudinal Handling---Stability---Tail Design
The present research aimed to study the effect of distilled water on impact strength for unsaturated polyester composites reinforced with E-glass fibers with volume fraction 35%, all samples were prepared by using hand lay up technique. Unsaturated polyester resin was used as matrix for the reinforced materials that consist of artificial glass fibers (woven roving) with directional (0,90) and chopped glass fibers with the random direction. The samples were cutting with measurement (60 x 6) mm and the sample thickness dependent on the number of layers of glass fibers. The impact tests are carried out on samples under the influence of normal conditions (laboratory temperature). The results and examinations for these samples shows acceptable improvement in impact strengths of the matrix was observed after addition of glass fibers, to explain the effect of water on impact properties, the samples immersion in water for (50) days. The results show that as the exposure time increased the impact strength of samples increase.