The White Cement Kiln Dust (WCKD) is a byproduct material, formed in cement factory during the operation of cement production. In highway construction, the WCKD can be used in different ways such as stabilizing the subgrade of highway embankment and as mineral filler in Hot Mix Asphalt (HMA); the latter usage will give clean and healthy environment in addition to more economy. In Iraq, there are two common types of fillers, Portland cement and lime stone powder. In this research, WCKD taken from Fallujah cement plant used as mineral filler in addition to two common types. Various percentages , such as 100%WCKD, 50%WCKD + 50%Cement(C) ,100%C , 50%WCKD+50%Limestone (L), and 100% L, were used to prepare asphaltic concrete mixes. In general, five tests were used to evaluate the performance of these mixes. Standard Marshall Test procedure was applied under three different conditions, two of them at two temperatures at 60 OC and 70 OC and in the third one it was used to test samples immersed in water, at room temperature(24 OC), for four days. Indirect Tensile Strength Test (ITST) was used to evaluate conditioning and un-conditioning samples. All test results, when compared with controlled asphalt concrete sample (Sample contained 100% limestone as filler), were acceptable and within the AASHTO and Iraqi Standard Specifications of Roads & Bridges 2003. Stability values, at standard condition test, of samples containing 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L are 11.9kN, 13.2kN, and 14.0kN respectively, while for controlled sample was 9.0kN. The Marshall stiffness values showed similar trends, for samples having 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L giving 3.22kN/mm, 3.38kN/mm, 3.5kN/mm respectively but for controlled sample was 2.43 kN/mm. Same trends of results gained in ITST .The results showed the beneficial using of WCKD as filler that will conserve the environment and encourage the HMA producers to use this inexpensive material in their works.
Previous studies showed that fire incidents cause a considerable deterioration of limestone samples' engineering and physical properties. Various laboratory tests were used in previous studies to investigate the properties of limestone. These tests included destructive and non-destructive tests like the hammer test, ultrasonic pulse velocity test, water-capillary rise test, and water transfer properties test, as well as destructive tests like the unconfined compression test and Brazilian tensile test. The stones of buildings exposed to fire are occasionally assessed on the site. This study analysed the physical and mechanical changes that occurred to the limestone samples when subjected to high temperatures, the damage mechanism, and laboratory or field damage assessment. This study also includes a review of the most significant studies that looked at how alternative cooling techniques—rapid water cooling or gradual air cooling—affect stone samples subjected to high temperatures and compared the behaviour of the samples in each scenario
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
One way of obtaining information about reliability of units is to accelerate their life by testing at higher levels of stress (such as increasing elevated temperatures or voltages). Predicting the lifetime of a unit at normal operating conditions based on data collected at accelerated conditions is a common objective of these tests. Different models of accelerated life testing are used for such extrapolations. Two statistical based models are widely used: parametric models which require a prior specified lifetime distribution, and nonparametric models that relax of the assumption of the life time distribution. The proportional odds model is a nonparametric model in accelerated life testing based on the odds function and show that it gives a more accurate reliability estimates than proportional hazard model. This paper will concentrate on the models of proportional odds nonparametric accelerated life test for reliability prediction.
The white cement Kiln dust (WCKD) is a secondary production from the cement industry through its production operation. Environmentally, it is considered as an unwanted waste because it causes air pollution and ground congealment, and it is needed great efforts and financial support to disposal it. In this study, the WCKD was used partially instead of limestone as a filler in the asphalt mix, where it was used by ratios of 0%,25%,50%,75% and 100% from the weight of limestone. An evaluation of the mechanical characteristics was conducted by carrying out Marshall test and Indirect Tensile test, and the results showed that the increase in the WCKD percent reduces the asphalt mix density and increases the percentage of air voids, while the other characteristics (stability, Marshall Stiffness, flow and Indirect Tensile Strength) increase when the WCKD ratio is 25% and 50%. These those characteristics start decreasing when the WCKD ratio was 75% and 100%. The study showed that the optimum ratio of the WCKD is 50% from the limestone weight, and the WCKD cannot be used as a filler entirely in asphalt mix, but it can be used partially.
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 research investigates the impact resistace of reinforced high strength concrete slabs with steel meshes (BRC) modified by styrene butadiene rubber (SBR) with different weight ratios of polymer to cement as follows: 3%, 5% and 7%. Reference mix was produced for comparison of results. For all selected mixes, cubes (100×100×100mm) were made for compressive strength test at (365) days. In conducting low-velocity impact test, method of repeated falling mass was used: 1400gm steel ball falling freely from height of 2400mm on reinforced panels of (50×50×800 mm) reinforced with one layer of (BRC). The number of blows causing first crack and final perforation (failure) were calculated, according to the former results, the energy of each case was found. Results showed an improvement in compressive strength of polymer modified high strength concrete (PMHSC) over reference mix; the maximum increase being of it were (3.93%-11.96%) at age of (365) days. There is significant improvement in low-velocity impact resistance of all polymer modified mixes over reference mix. Results illustrated that polymer modified mix of (3%) give the its higher impact resistance than others, the increase of its impact resistance at failure over reference mix was (154.76%) while, for polymer modified mix (5%) it was (30.95%) and it was (14.28%) for polymer modified mix of (7%).
This paper is aimed to study the effect of SiC addition as reinforcement to 6061 T6 alloy. Al 6061 T6 alloy SiC composites were prepared by melting the alloy in a vortex and adding 4 % and 10% weight fractions of SiC. Then pouring the mixture into a mould to obtain a bar of 12 mm diameter and 150 mm length. Wear specimens were manufactured in dimensions of 20mm x 10mm according to ASTM to the base alloy and the cast matrix alloy. Microstructure have been carried out to understand the nature of structure and Hardness test also implemented to specimens. Adhesive wear test have been conduct both on the alloy and composites at different parameters (time, load and velocity). From the obtained results, it was found that wear resistance improved during the carbide addition comparing with the base alloy as a result of SiC addition which contributed in improving the hardness of the alloy that reflects to the wear resistance and these properties were improved as the increasing of the carbide silicon percentage.
In this study the effect of sodium hydroxide on the strength of clayey soil-cement mixtures was investigated. Clay soils from three various locations of Kirkuk governorate namely Erbil, Laylan and Hawija check points were used. The effect of cement content, curing age, curing temperature and concentration of sodium hydroxide on the strength of soil-cement mixtures were investigated, through carrying out unconfined compressive strength, Triaxial compression and C.B.R tests. It was found that the use of sodium hydroxide markedly improves the strength of soil-cement mixtures. The addition of about 1% of sodium hydroxide by weight of soil could reduce about 5% of cement content by weight of soil required to stabilize the soils effectively.
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.
This study is the second stage of the paper “Studying the Effect of Rubber- Silicone on Physical Properties of Asphalt Cement”. The present study examines the effect of additives on asphalt mixture performance. Asphalt mixture has been designed by Marshall Method for determining the optimum asphalt content and geophysical properties of mix according to ASTM (D-1559). Rubber-silicone at different percentages (1%, 2%, 3% and 5%) was added to asphalt binder. Six specimens of asphalt rubber silicone mixture (ARSM) for each percentage are prepared and evaluated according to Marshall method. Diametric tensile creep test ASTM (D-1075) at 60 Co was used to evaluate permanent deformation and modulus of elasticity for ARSM. The study showed that the Rubber-Silicone has more effects on performance of asphalt mixture by increasing the Marshal stability, air voids, and reducing the flow and bulk density compared with the original mix. It also increases the flexibility properties of the mix and this appears from reducing the permanent deformation at test temperature (60C), the reduction percent is about (30 to 70) %.
Some mechanical properties of mortar (compressive strength and hardness) with sawdust replacement of sand were investigated. Cubes of 50 mm × 50 mm were prepared, the compressive strength tests were done for a replacement levels ranging (5, 10, 15, 25, 50, 75) % by volume a reference mix were also prepared for comparison this test was done after 7, 14, and 28 days while hardness test were done after 28 day for a replacement levels (0, 5, 10, 15, 25) % by volume. Result showed that the compressive strength of the specimen were decreased with higher sawdust content, hardness values were decreased slightly in the replacement levels 0, 5, 10 % while the values began to decrease noticeably in the replacement levels 15 and 25 % the hardness values were (59, 57.5, 56, 47.77 , 45.2) N/mm2 respectively A cost analysis was done, this analysis was based on a unit of mortar (1.0 m3) made from conventional materials and a modified concrete made by substituting materials with sand using sawdust
An experimental investigation is performed to study the friction factor ( f ) and convection heat transfer coefficient (h) behavior in an asymmetrically heated equilateral triangular duct by using delta–winglets vortex generators which are embedded in a turbulent boundary layer. Two side walls of the heated test section are electrically heated with a constant heat flux, whereas the lower wall is indirectly heated. Reynolds number (Re) is ranged from (23,000) to (58,000). Two sizes and three attack angles of vortex generators are studied here for three cases; single, double, and treble pairs of generators. Each pair was supported in one wall of the test section at the various locations from the leading edge. The indicated results that friction factor ( f )and Nusselt number (Nu) are relatively proportion with the size, number and the inclination angle of the generators. The ( f ) decreases as airflow rate increases whereas Nu number increases. The present data of ( f ) is less than the data of Chegini by about (6.5 %) and overpredicts the data of Altemani by about (1.7 %).
Ten simply supported deep beams with high strength concrete (C55 MPa) have been casted and subjected to a four-point loading test. Different parameters were examined for their influence on specimen behavior. These parameters were the shear span to overall depth ratio (a/h), the overall depth of deep beams (h), and additional anchorage length beyond the centerline of support (la). The experimental results show that the beam capacity decreases as the shear span to the overall depth ratio increases, and the overall depth and embedment length decrease. The major effect of anchorage length on the shear strength is studied. Different failure modes were observed which do not match strut-and-tie failure modes. The shear compression and anchorage failures were con-trolled in the high compressive concrete deep beams due to bottom steel yielding. Finally, the ex-perimental test results are compared with predictions of the strut-and-tie method according to the ACI 318-14 and a good agreement was found.
The aerodynamic characteristics of forward swept wing were studied theoretically and experimentally .In the present work, theoretically a computer program was constructed to predict the pressure distribution about surface of the wing using three dimensional Low Order Subsonic Panel method. The aerodynamic coefficients of the wing were calculated from the pressure distribution which gained from tangential velocities Experimentally ,test were carried out by designing and manufacturing a wing model with special arrangement for pressure tapping, suitable for low wind tunnel testing. The entire wing was rotated rotate about an axis in the plane of symmetry and normal to the chord to produce different sweep and incidence angles for wing, by using rotating mechanism. Wind tunnel test was carried out at (Uپ‡=33.23m/s) for different swept angles and angles of attack.Comparisons were made between the predicted and experimental results. It is good and gave reasonable closeness. It was clear from the present investigation that the lift and drag characteristics for the forward swept wing are less in values compared with the swept back wing, therefore a forward swept wing can fly at higher speed corresponding to a pressure distribution associated for lower speed.
In recent decades, functionally graded porous structures have been utilized due to their light weight and excellent energy absorption. They have various applications in the aerospace, biomedical, and engineering fields. Therefore, the balance between material strength and light weight is the goal of the researchers to decrease the cost. Samples of PLA material were designed and manufactured using a 3D printer according to international standard specifications to study the effect of porosity gradient through thickness. An experimental three-point bending test was performed, and then simulations were performed using ANSYS 2022 R1 software on samples with functionally gradient different porosity layers to verify the experimental results. The results from the experiment and the numerical values were in excellent alignment with an error rate of no more than 13%. The maximum bending load and maximum deflection of the beam were specified experimentally and compared with the numerical solution. The maximum bending and the maximum deflection When the porosity layer in the middle of the beam, matched the ideal maximum bending load (190,194) N experimentally and numerically, respectively. The maximum deflection (5.9,6.4) mm experimentally and numerically, respectively was obtained in samples with varying porous layers.
Deep beams with rectangular cross-sections are widely used in concrete structures. In the present study, reinforced concrete rectangular deep beams cast with self-compacted concrete (SCC) which contains recycled concrete as coarse aggregate (RCA) were tested under directly and indirectly loading conditions. In the experimental work, fifteen deep beams were investigated, the first parameter considered in this study was the shear span to effective depth (a/d) ratio. The other variable is the replacement ratio by which the normal coarse aggregate is replaced by RCA. The beams were cast without the use of shear reinforcement. During the tests, the response of the beams including the cracking load, the ultimate load, concrete strain, and mid-span deflection were recorded. Test results indicate that the presence of RCA caused a reduction in the values of cracking and ultimate loads. For instance, the cracking load was reduced by 9%, 23%, and 50% and the ultimate load was reduced by 2% , 23%, and 25% as RCA replacement increased by 25%, 50%, and 75% respectively for a/d ratio equals 1.0. Further, by increasing the a/d ratio, the ultimate load was decreased due to the lower contribution of arch action shear transfer in the beam with a higher (a/d) ratio.
The detection of faults in electronic circuits is crucial to ensure the proper performance and reliability of electronic applications that utilize these devices. This work discovers, for the first time, that a direct tester board for fault diagnosis can be used not only for the intended measurement of current and voltage but also for studying the potential development of these magnitudes in inaccessible locations, as it detects register transfer level signals through oscilloscopes with low acquisition speeds. The experimental analysis carried out combines the use of commercial software with spatial distribution tracking and the exploitation of the sizes of network links in their computer graphical representation. The proper detection of malfunctions in electronic systems is crucial for enhancing their performance and reliability. We intend to explore the troubleshooting of analog electronic systems, for which we use wide-band direct tester boards. To evaluate its performance in routine practice, we perform experimentation using two different analog circuits designed. They consist of conventional operational amplifiers and element modeling based on equivalent resistance-capacitance networks. Given the procedure followed, commercial programs were used. Special mention should be made of the conclusion matrix, which is interesting when selecting suitable diagnostic parameters. The effectiveness of direct measurement based on integrated probes in the two projects, which allowed for fault insertion, was also confirmed. The results and discussions were enriched by the summarized experimental test report. The work concludes with a reflection on the relationship between this work and the existing state of the art, as well as the new challenges posed by international researchers.
The concrete members several blessings over steel beam, like high resistance to prominent tem-perature, higher resistance to fatigue and buckling, high resistance to thermal shock, fire re-sistance, robust resistance against, and explosion. However there are some disadvantages as a result of exploitation totally different materials to product it. The most downside of structural concrete member is its deprived the strength to tensile stresses.The bond mechanism between steel bars and concrete is thought to be influenced by multiple parameters, like the strength of the encompassing media, the prevalence of cacophonous cracks within the concrete and therefore the yield stress of the reinforcement. However, properties of concrete mass has significantly effect when it was subjected to elevated temperature.The objective of this paper presents the results that allocating with the bond behavior of the rein-forcement of steel bar systems below static pull-out loading tests subjected to elevated tempera-tures. This numerical technique relies on relative slip and therefore the stress of bond distribu-tions done the embedded length and size of the bar within the concrete cylinder specimens. The obtained results square measure given and commented with the elemental characteristics of ferroconcrete members. The comparison showed smart agreement with experimental results
The presented work investigates the effect of addition admixture (cement kiln dust) to concrete as a partial replacement of cement weight. Cement kiln dust was added by (10,30,50)% of cement weight.Four mixes were selected, three of them contain cement kiln dust (CKD) and one reference mix without any admixture for ages (7,28,90) days. Compressive strength ,flexural strength, ultra-sound velocity (UPV), slump, splitting tensile strength and static modulus of elasticity were tested.The test results indicated that the use of (CKD) led to significant decreasing in concrete strength in general and this decreasing increases with the increasing of (CKD), for example at 28 day the compressive strength of reference concrete (A) was 35 MPa, while the compressive strength of (B,C,D) contain (10,30,50)%CKD were (28,25,22) MPa respectively.
Cosmetic surgery is more prevalent in the world in recent years. A beautiful and flawless face is everyone's dream. Aging, environmental factors, disease, or poor diet are among the factors that influence body wrinkles. Various methods are used to reduce these lines. It can be said that the simplest and most effective solution is to inject cosmetic fluids into these areas. But, due to the increase in facial injections using cosmetic fluids, which are considered toxins, the risk of injury to the surrounding facial nerves and injury to one of the main facial nerves is increasing, creating a catastrophe or deformation in the face irreversibly. Deep learning algorithms have been used to determine whether cosmetic fluids are injected or not. Deep Convolutional Neural Networks (CNNs), VGG16, ResNet....etc deep learning algorithms have demonstrated excellent performance in terms of object detection, picture classification, and semantic segmentation. all the suggested approach consists of three stages: feature extraction, training, and testing/validation. Deep learning technology is used to train and test the system with before and after photographs. Numerous investigations have been carried out using various deep learning algorithms and databases the main goal is to attain maximum accuracy to ensure that injected cosmetic fluids by specialists have been injected in safe areas in addition to facial recognition and determining whether or not the person received an injection. The most used databases are IIITD plastic surgery and HDA_Plastic surgery.
The present research is devoted to solve the problem of high energy consumption by air conditioners in summer. In order to eliminate domestic electricity for cooling purposes and rely directly on solar energy isolated from the grid connection and increases the performance of the solar panel by using front water spray cooling system for the panel, and by using Adruino as controller to control the cooling system. The experimental system setup arranged in Iraq at Al-taje site during the summer season at a room. The proposed system consists of an array of photovoltaic, battery used to store power, PWM charge controller, and DC air cooler, Adruino. During the examination of the system, The enhancement of the solar panel has a positive effect on long-term batteries and improves the battery life by which the charge and discharge when combined with a direct photovoltaic air conditioning system without refrigeration. Excess power generated from the PV panels is storage in the batteries, which make the system is the most familiar with Iraq's summer conditions
The performance of electronic devices, especially computers, depends on the efficiency of the electronic chips and Computer processing units, which are mainly made of semiconductors, so their working efficiency is inversely proportional to their working temperature. Therefore, this paper presents an experimental investigation of the design, implementation, and testing of three cooling systems to maintain the temperature of the processing unit as minimum as possible. The first is a traditional system dissipates heat from the working fluid to the air through a finned tube heat exchanger. The second successive hybrid system was designed to integrate with the first one in addition to a thermoelectric cooling system to cool the working fluid. The third system included in addition to the traditional heat dissipation one, an intercooler cylinder with a large quantity of the working fluid in the main system beside a separate system for cooling the working fluid using thermoelectric cooling to ensure sufficient cooling of the processing units when working at high frequencies by providing a large capacity of working fluid pre-cooled to a low temperature. Comparing the experimental results of the cooling systems with the traditional one under the same test conditions showed that the second system led to a reduction in the temperature of the processing unit by 5.2%, while employing the third system reduced the temperature to 11.3%., When the thermoelectric cooling unit operates at a performance factor of about 1.76.
In this work the effect of degassing on hardness and microstructure of aluminum recycled cans using aluminum beverage cans scrap from different locations in Baghdad wastes had been studied. Aluminum cans were shredded and ground into small pieces. It was processed through a gas fired to eliminate the coated layer (paint or lacquer on the metal). Generally the scrap is divided into two groups before charging to the furnace, one without adding degassing and the other degased with (Ar-N2). When temperature exceed 690C° molten aluminum was pour into two molds, after cooling. The two ingots were expose to porosity test, hardness, and microstructure. It was found from recycled cans ingot behave like short freezing range alloys. The main form of shrinkage porosity is localized external sink, appeared at the heat centers or at last region to be solidify. This had been verified clearly by microstructure of many regions of the ingot without adding a degasser. Either defect or decrease in hardness was clearly seen in the ingot without degassing addition. In addition to oxides, a number of additional compounds could be considered inclusions (intermetallic phase particles) in cast structures. Where the main conclusion was to remove gases without using a degassing to ingot decadence on the first gas fire on the cans to remove all paint or lacquer on the metal, but this was not sufficient and properly we need to add degassing to ingots. Finally this was clearly shown from the results of the ingot with adding a degassing had 89 kg/mm2 HV rather than 61 kg/mm2 for ingot without degassing
Experiments were carried out on natural convection heat transfer from longitudinal trapezoidal fins array heat sink subjected to the influence of orientation. A trapezoidal fins heat sink with various orientations tested under a controlled environment. Test results indicate that the sideward horizontal fin orientation yield the lowest heat transfer coefficient. However the sideward vertical fin orientation gave the best performance on the natural cooling. From the experiments Nu is determined as a function of Ra at Pr=0.7 for each orientation with Ra ranging between (1400 and 3900).From the results; Heat transfer coefficient of the sideward vertical fins is higher by (12%) than the heat transfer coefficient of the upward while it is higher than the heat transfer coefficient of the downward by (26%) and by (120%) with the sideward horizontal fins. Orientation affected the temperature distribution along the fins, therefore the temperature along the sideward vertical fins have the best performance with uniform distribution, while in sideward and downward the temperature increased in the positions near the base plate surface because of the complication in moving the heated air.
Switched reluctance motor (SRM) is an electric motor works based on the reluctance torque produced due to the variation of the rotor pole position with respect to stator poles. This paper adopts a thermal analysis on a 4-phase, 8/6 pole, 550W, SRM. Lumped parameters thermal network method(LPTN) is used in this analysis based on a combination of RMXprt/Motor-CAD software, in two- dimensional(2D), steady-state, with different cooling methods, and with different loading conditions. Motor losses like core losses, copper losses, and mechanical losses are regarded as the heat sources in SRM which are calculated by RMXprt software. The thermal analysis achieved by Motor-CAD includes displaying the temperature distribution on different motor parts like stator winding, stator poles, stator yoke, rotor poles, rotor yoke, shaft, covers, and housing. The analysis results showed the increasing temperature distribution on different motor parts with increasing motor loading conditions. Also, this temperature distribution is recorded using three different cooling methods. The comprehensive thermal analysis applied in this work will assist the motor designer in choosing a better motor thermal design without needing to produce and test costly prototype motors.
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%).
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.
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).
sphalt is the most recycled materials around the world and the amount of RAP materials can be significantly increased with the application of good RAP management applications. In Iraq, the real inclusion of RAP materials in asphalt mixtures has not been applied yet in the field. It is therefore that there is a need to characterize the effect of inclusion RAP materials in asphalt mixtures with particular reference to permeant deformation/rutting resistance. The aim of this study is to evaluate the best layer of pavement structure; base, binder, and surface layers for inclusion (RAP) materials. In addition, highlight the best percentage that can be added from RAP to achieve positive results and better than that associated reference mixture in terms of rutting resistance. RAP materials collected from different sources Karbala and Fallujah, were adopted in this study at percentages of 20%, 30%, and 40% by weight of the asphalt mixture. Two scenarios of incorporating RAP materials have been adopted. The first is considered that RAP as a black rock in which the effect of aged binder surrounding the aggregate of RAP is neglected while, the letter is not considered RAP as black rock and the influence of aged binder in RAP materials has been taken into consideration. Dora bitumen has adopted in the current study which is used in common in Iraq. It has been highlighted the best layer in which RAP can be incorporated is the base layer, with a percentage up to 40% that RAP without considering RAP black rocks regardless the sources of RAP.
The universal motor, versatile and capable of running on both AC and DC sources, is utilized in various household appliances and power tools. This paper presents a featured methodology for analyzing a universal motor (UM) that does not have design data by extracting it via reverse engineering. These gained data were used to model the motor by Maxwell program and analyzing it by finite element method (FEM). Adopting the Maxwell program's drawing capability to design the square-shaped stator of a universal motor not part of the program library will also enable the Maxwell program to be widely used and unrestricted to use with particular motor designs. After modeling and solving the motor model, the performance characteristics of UM when operated with alternating current (AC) and direct current (DC) power supplies were investigated. The UM simulation results were compared with test results with good agreement. The success of a proposed methodology paved the way for the analysis of any electric motor included in the Maxwell program, even if this motor does not have design data.
The direct sequence (DS) spread spectrum communication technique is widely regarded as one of the most effective methods of mitigating the effects of a repeating jammer in military communications systems. The proposed system coupled DS with multiple frequency shift keying (DS/MFSK). It is comprised of a transmitter and a receiver. Non-coherent demodulation is examined, as are the spreading sequences in question. The effect of AWGN and Rayleigh fading channels on the proposed approach's bit error rate (BER) is examined. The investigation demonstrates that even with an 8 dB signal-to-noise ratio, superior outcomes can be achieved; this study's suggested endeavor is to create a novel transceiver system built on the DS/MFSK modular architecture. MFSK modulation prevents multiple-access interference, while DS is typically employed to boost system efficiency across erratic fading. Test results show that reliability on the AWGN channel decreases a little while reliability is greatly enhanced by Rayleigh fading. Moreover, notable improvements in bandwidth efficiency are achieved.
This research, an attempt is carried to explain the use of new products of superplasticizers type (Glenium) locally recent period used in normal concrete strength,espeacailly in precast concrete. and the effect of medium hot weather climates on compressive strength of normal concrete made with various percentages of Glenium dosages , and to evaluate the dosages on workability of fresh concrete. Concrete mixes with two types containing of Glenium, G51 and G21. and different dosages of Gelnium, namely 0.8 and 1.2 liter per 100 kg of cement and reduction in water quantity about 25% Five mixes are made with 90 specimens, each mix contains 18 cubes ,half of specimens are cured by moist curing in normal condition, the other half of specimens are exposed to temperatures of 40oC.which is transferred to moist medium of hot water. The properties which are covered in this work consist of workability which represented by slump test, and strength represented by compressive strength and ultrasonic pulse velocity(UPV) tests. It is obtained that using the two types of Gelnium will improve the slump about (157% to 183%) compared with reference mix .The concrete cured at medium hot weather condition, show improves in compressive about (19.2 to38.12%) at 3 days age. The use Glenium type 51 is to be more suitable for normal concrete works in medium hot weather .
The presented work investigates the effect of addition admixtures (superplasticizer and polymer) to Chopped Worn-Out Tire concrete as a partial replacement of cement weight. Superpasticizer was addition by 4% and polymer (SBR) by 15%. The Chopped Worn-Out Tire (Ch.W.T.) addition to reference concrete with the three proportions as a Partial Replacement Ratio (PRR) of (25,25),(20,30),and (30,20) by volume of (sand and gravel) respectively. Three mixes were selected with above PRR for each type of admixture in additional to three mixes for Ch.W.T. concrete without admixtures and three reference mixes with admixtures without Ch.W.T. Thus, twelve mixes could be used in this investigation. Compressive strength and modulus of elasticity (static and dynamic) were tested. The test results indicated that the use of admixture led to significant improvement in concrete properties in general. Superplasticizer gave best results comparative with polymer, for example at 28 day the compressive strength of superplasticizer Ch.W.T. concrete Csp25,25 was 32.5 MPa, while compressive strength of polymer modified Ch.W.T. concrete CB25,25 was 28 MPa and compressive strength of Ch.W.T. concrete C25,25 was 21.2 MPa.
This paper contributes to the field of improving the performance of heat exchangers using metal foam (MF) full-filled and partially/periodically-filled within the gap between the two pipes. The effect of configuration and arrangement of copper MF (15PPI and porosity of 0.95) installed on the outer surface of the inner pipe of a counter-flow double-pipe heat exchanger on the thermal and hydraulic performance was studied experimentally. The test section consisted of concentric two pipes; the inner pipe which was made of copper while the outer pipe was a Polyvinyl chlo-ride. Air was used as a working fluid in both hot and cold sides. A wide cold air flow rate range was covered from 3 to 36 m3/h which corresponds to Reynolds number (Re) range from 2811 to 31,335. The hot air flow rate was kept constant at 3m3/h. The temperature difference (ΔT) be-tween the inlet hot air and inlet cold air was adopted to be (20°C, 30°C, 40°C, and 50°C). The re-sults revealed that the higher Nusselt number (Nu) was at ΔT= 50°C and the thermal performance of the heat exchanger with the MF for all the arrangements was greater than the smooth heat exchanger. The highest and lowest friction factor was 1.033 and 0.0833 for the case 1 and 8, re-spectively, and the optimal performance evaluation criteria (PEC) was 1.62 for case 7 at Re = 2800. The Nu would be increased with a moderate increase in the friction factor by optimizing the arrangement of the MF. The two essential parameters that played an important role for in-creasing the PEC were the MF diameter and the MF arrangement along the axial length of the cold air stream.
This research focuses on studying the speed flow density relationships which are considered the fundamental traffic flow relationships. The objective of the present study is to predict statistical models represent these relationships depending on a field survey data collected from Al-Thirthar road in Falluja city.Data were collected by using video-recording technique. The required data were abstracted, analyzed, grouped, and processed using computer programs developed for this purpose. Standard statistical analysis techniques were used to examine and analyze the observed data.FWASIM simulation traffic software program was used to verify the predicted traffic stream models, while the obtained results were presented in this research. To test the validity and reliability of the model, the output results of the predicated model were compared with the output data obtained from FWASIM model using similar input data and segment geometry. The comparison leads to consider that the developed regression model may be used to evaluate the performance of urban streets in Falluja city.
Pile foundations are typically employed when top-soil layers are unstable and incapable of bearing super-structural pressures. Accurately modeling pile behavior is crucial for ensuring optimal structural and serviceability performance. However, traditional methods such as pregnancy testing, while highly accurate, are expensive and time-consuming. Consequently, various approaches have been developed to predict load settlement behavior, including using artificial neural networks (ANNs). ANNs offer the advantage of accurately replicating substrate behavior's nonlinear and intricate relationship without requiring prior formulation.This research aims to employ artificial neural network (ANN) modeling techniques to simulate the load-settlement relationship of drilled piles. The primary aims of this study are threefold: firstly, to assess the effectiveness of the generated ANN model by comparing its results with experimental pile load test data; secondly, to establish a validation method for ANN models; and thirdly, to conduct a sensitivity analysis to identify the significant input factors that influence the model outputs. In addition, this study undertakes a comprehensive review of prior research on using artificial neural networks for predicting pile behavior. Evaluating efficiency measurement indicators demonstrates exceptional performance, particularly concerning the agreement between the predicted and measured pile settlement. The correlation coefficient (R) and coefficient of determination (R^2) indicate a strong correlation between the predicted and measured values, with values of 0.965 and 0.938, respectively. The root mean squared error (RMSE) is 0.051, indicating a small deviation between the predicted and actual values. The mean percentage error (MPE) is 11%, and the mean absolute percentage error (MAPE) is 21.83%.