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Go to Editorial ManagerUtilization of additives can be an effective way to improve the durability and performance of HMA, making them more resistant to Moisture and deformation. Plus, they can reduce the need for maintenance and repairs, saving you time and money in the long run. In this study, CKD was used in place of limestone as a filler in the asphalt mixture in proportions of 0%, 25%, 50%, 75%, and 100%, and polymer SBS 4%by weight of asphalt. According to the findings, replacement-content CKD had the highest asphalt content. When the CKD is between 25% and 50%, Stability, Flow, and Indirect Tensile Strength are improved, while the density of the asphalt mixture decreases and the amount of air voids increases at higher ratios. While SBS leads to an increase in the hardness of the adhesives. As a consequence, the stability of the SBS-containing mixes resulted in higher values than the control and additive-containing mixtures (CKD), as well as a decrease in the number of air voids. According to the results, CKD should not constitute more than half of the filler weight in the asphalt mixture.
Most of the soils suffered from significant geotechnical problems dependent on factors like the type of soil, soil composition and mineralogy. Specifically, the problems related to mechanical and physical properties of soils. Several studies have been used to mitigate the adverse effects of soils through using either additive conventional materials such as cement, lime or these soils blending with produced material and chemical materials. This paper focuses on stabilizing or improving different soils using sustainable materials. These materials provided environmental and economic benefits while mitigating a health hazard, storage problems, and a potential pollution source. They can be classified according to these sources into four groups: industrial waste (by-products), agriculture waste, domestic waste and mineral waste. According to the results of this review, compaction characteristics, California bearing ratio and unconfined compressive strength have been studied and discussed in this paper.
Openings in reinforced concrete (RC) slabs are usually created as a result of variations in construction function, architectural or mechanical necessities. Heavy equipment loads resulting from mechanical system of any building are often carried by RC slabs. Even the static analysis and design of RC slabs with opening is not clearly stated in the available international Codes, dynamic analytical solution for such structure is complex._x000D_ In this paper, numerical analysis based on finite element approach is utilized to implement the modal analysis of RC slabs. Opening size and position was parametrically studied. Slab natural frequency or periods in addition to, the mode shape were registered. The results showed that the opening size and position involved in RC slab had a significant change in the value of natural frequency and period for the high level modes. The material nonlinearity affect on free vibration analysis of RC opening slab with different levels of stiffness modifiers was taken into account. The dynamic characteristics of RC opening slab as a function of stiffness modifier degree was numerically measured for six mode shapes. The paper found that a reduction in stiffness modifier value greatly reduce the .natural frequency of RC opening slab.
Due to the instability and irregular of national electric power supplied to residence sector in Iraq for long term history, attracted researchers interest to strive for solutions, and associated challenge dry and very hot summer season in Iraq on air conditioning application, A test room full size prototype was constructed in Baghdad, its size 33.5m3, the room is built from very good thermal insulation Autoclave Aerated Concrete AAC with white panted Concrete roof, test room is exposed to solar radiation during entire day, thermal energy shifted by time using thermal energy storage TES containing PCM, PCM is soft paraffin its phase inversion temperature (29 to 27)°C, thermal energy was shifted from night timing by cooling down TES (Discharging PCM) to peak time 11:00 am to 02:00 pm, the testes were carried out over entire summer season April to October, the results showed thermal energy can shift to by any quantity and time based on mass of PCM and enthalpy, electrical energy saved at peak time 52.5% of total power spent over season 2.7KW/day, Only 27% of electric energy utilized to discharge PCM during night, about 43% of heat lose is sourced from exposed roof, melting and solidification of PCM temperature must be within indoor comfort range 23 to 28 ?C to release or absorb the latent heat 41kJ/kg.
Shear walls are effective structural elements used mainly in multi-story buildings to provide resistance against lateral loadings such as earthquake and wind loadings. There are several types and shapes of shear walls depending mainly on geometry and height of the building. Both type and shape of the shear wall affect the efficiency of resisting lateral loadings. In this study, fifty six building models have been analyzed using the finite element method by using the SAP2000 V14 computer program. Each model have ten stories, subjected to earthquake loadings, with various numbers of bays, and with three types of shear walls, namely: side shear walls, middle shear core, and double shear cores, provided that each type of the shear walls (or cores) has the same material volume. The analysis outputs have been investigated to select the appropriate type and location of the shear walls (or cores) for the multi-story buildings subjected to earthquake loadings. Specified conclusions have been presented to obtain the optimum behavior for the multi-story buildings under the effects of earthquake loadings.
Desired mechanical properties like microstructure, micro hardness and wear resistance are the key parameters for which low carbon steel (AISI 1006) are widely selected. Surface heat treatment applied to improve these properties; traditionally surface heat treatments like induction hardening, in recent time’s laser surface hardening. In this work, thermochemical treatment (liquid nitriding) by using mixture from 61% NaCN, 15% K2CO3 and 24% KCL and followed by Nd:YAG laser surface treatment was done . The laser parameter were energy (0.89, 2, 4 and 9) J, spot diameter (0.790 ,0.33, 0.283 and 0.224) mm, pulses duration (1, 2.33, 4.47 and 9.87) ms with fix wavelength 1604nm. Laser surface treatment cycle was melting the layer surface, holding and rapid cooling in air medium. Optical microscopy (OM) and scanning electron microscope (SEM) has been used to study the microstructures and cross-sectional of molted and heat affected zones respectively. The wear test was done to measure the wear rate by using pin -on-disk principles were satisfied. The result shown that increasing in laser energy effects to increase in the area of melted and heat affected zones of nitriding steel. Also increasing in laser energy led to increase micro hardness about 61%, while wear rate decrease about 40 % and increased depth of molted zone.
The 3-D numerical simulations of the thermal collectors in solar heating systems were conducted to simulate the conventional solar heating system, multipurpose solar water heater (MPSWH), and multipurpose solar air heater (MPSAH). The commercial computational fluid dynamics (CFD), AVL Fire ver. 2009.2 was used to solve and investigate the temperature distributions in the absorber plate and riser tube of both solar water and air heater during summer and winter seasons. The RNG k -turbulence model was employed for this CFD study. The present paper was to provide a good understanding of thermal performance for the solar collector at different operating conditions. The experimental setup and physical data of Venkatesh, R. and Christraj, W. [15] were employed as geometric parameters and initial boundary conditions to model and to validate the predicted numerical values. Comparing to the values of temperatures for the conventional SWH and SAH, the predicted results of the MPSWH and the MPSAH showed a good improvement on the thermal performance. These enhancements on the temperature may have been due to the new design adopted in the multipurpose solar heating systems by using riser tubes and headers to the original design of the thermal systems. Additionally, the thermal performance of solar collectors increases with increasing the mass flow rates and thermal conductivity of absorber plate. For validation aspect, the predicted results of all cases examined showed a good agreement against the measured results in terms of temperature distribution levels and thermal efficiencies.
The aim of this study was to support surgeons to decide where to place the screws in order to achieve an optimal fracture healing and to prevent implant failure after a femoral shaft fracture So this paper focus on the analysis of bone-plate construct by using Finite element Analysis (FEA), comminuted femur fractured bone fixed with Dynamic Compression Plate (DCP) 16 holes by 4.5 Cortex screws, to investigate the effects of screws configuration on the mechanical behavior of different seven model as Interfragmentary strain which is the most important factor for femur fracture healing. The results state the relationships between the Von-Mises stress, Total deformation and Interfragmentary strain with respect to the screws configuration. The study shows the regions of maximum stress from stress distribution and also founded that we can decrease the Interfragmentary strain by increasing the number of screws.
In Iraq some pavements of the newly constructed highway appear precocious distresses with unfavorable implications especially on the safety and the frugality. Cracking and permanent deformation are main types of these failures. The filler is doubtful to be a master contributor to these failures where its content has a significance effect on the mixture stiffness, and thereby affect the HMA pavement performance. The main objective of this research is to appreciate the influence of different contents of filler on the volumetric properties of asphaltic mixtures thus performance of asphalt mixtures through Comparative Evaluation between conventional Marshall Method and Super pave system. The implementation of a detailed experimental work is carried out to achieve the study objectives through the preparation of asphalt concrete samples using aggregate from Al-Nebaie quarry, (40-50) asphalt cement from Dourah refinery and limestone dust filler with four different contents of (0%, 4%, 8%, and 12%) by weight of the total aggregate. The volumetric properties for each mix design method are evaluated using Marshall Test and the Super pave Gyratory Compacter. The influence of filler contents on the rendering of these mixtures was evaluated.
Türkiye possesses abundant geothermal resources. It is ranked seventh globally for this particular energy resources and grade among the first 5 in utilizing geothermal and thermal springs for various purposes such as electricity generation, residential cooling and heating, greenhouse operations, desiccating processes, thermal recreation, therapeutic applications, mining, agricultural uses, and aquaculture. The government's endorsement from renewable power sources is fueling growing interest on this particular energy sector. This article provides a comprehensive analysis of geothermal energy in select locations of Türkiye, including an assessment of its potential and various applications. The study seeks to provide a valuable involvement to the future advancements of a geothermal technology on Türkiye.
Consider polymers and polymer matrix composite are the basis of the most prevalent material in all industrial and medical fields because of its properties qualify to occupy an advanced position among other engineering materials because of its good properties._x000D_ Therefore, This work focuses on the preparation of base polymer matrix composite materials and study non-saturated polyester as matrix has been strengthened by zeolite particles different grain sizes (25 - 65 - 75) µm and different volume fractions (1,5 - 3 - 4,5 - 6 - 7,5 - 10) % was strengthened by Carbon short fibers and constant volume fraction (8%),the tests tensile and bending according to ASTM specifications, respectively. Through the results it was observed that the maximum tensile strength improved through hybrid reinforcement when reached the maximum value when the grain size (25 µm ) and at volume fraction (7.5%), reaching ( 94 N/mm2 )compared with the rest of sizes and at the same volume fraction reaching (78 N/mm2 for 65 µm , 69 N/mm2 for 75 µm), As for the bending test has been getting maximum Flexural resistance at grain size (25 µm) at volume fraction ( 6%) reached to(111 N/mm2) ,if compared with the rest of sizes at the same volume fraction reaching (100 N/mm2 for 65 µm,79 N/mm2 for 75 µm) while was obtained on the maximum bending modulus at grain size (25 µm) and at volume fraction (10%) reach to (8099 N/mm2) if compared with the rest of sizes at the same volume fraction reaching (7466 N/mm2 for 65 µm, 6666 N/mm2 for 75 µm ). Through the results we note that for the particle size and fiber effect in improving the mechanical behavior of the composite material prepared.
In this work, nine types of laminated composite materials used for experimental study to investigate the tensile and fatigue properties of partial foot prosthetic socket which fabricated by using vacuum pressure system . The composite material matrix were Lamination 80:20and reinforced with nine types of laminations (perlon, n-glass, fiber glass and carbon) by variation of thickness according to lamination. Results show that the mechanical properties were improved by increasing the two layers of carbon fiber, fiber glass and n-glass layers instead of zero layer with six layers of perlon lead to the increased in(yield strength ?y, ultimate tensile strength ?ult and modules of elasticity E with (71% ,76% and 58%) respectively for carbon fiber, (20% , 19% and 40%) for fiber glass and ( 22% , 5.5% and 29% ) for n-glass. Results show that (3perlon+2carbon fiber+3perlon) gives the best value of mechanical properties and has higher Endurance limit stresses (?e) which increase lifetime for the patient . It is recommend to use this type of lamination for the layup partial foot prosthetic socket because it meets the demand lamination layers for acceptable mechanical properties and its minimizing the cost of socket lamination to suitable costing value.
Additionally, it has been demonstrated that osseointegrated implantation offers superior proprioception and control over the prosthesis, enabling more natural movement and improved functional results. Additionally, it lowers the chance of falling and increases energy transfer efficiency, making it simpler for amputees to engage in physical activity. Furthermore, as compared to conventional socket prosthesis attachment, osseointegrated implantation has been linked to higher patient satisfaction and quality of life._x000D_ It is crucial to remember that osseointegration is a surgical operation with risks including infection and implant failure. Additionally, for effective implantation, it needs a specific amount and quality of bone, which may restrict its usage in some individuals. Furthermore, osseointegrated implantation could be more expensive than conventional socket prosthetics._x000D_ Understanding the efficacy and safety of this method requires research on complication rates and outcome metrics in patients having osseointegrated prosthesis implantation. You may acquire information on things like infection rates, implant failure, patient satisfaction, and functional results by studying original research papers. Clinical decision-making can then be improved with the use of this information._x000D_ In transfemoral amputees, osseointegration has showed promise as a powerful substitute for socket prostheses. A growing corpus of research has shown that osseointegrated implantation provides advantages in terms of increasing mobility, decreasing discomfort, and improving general quality of life. The efficiency of osseointegration for transtibial and upper extremity implants has received little attention._x000D_ Minor soft tissue infections are the most frequent consequences, although they are manageable with the right treatment and monitoring. To further reduce the risk of problems and improve the overall success of osseointegrated implantation, research and development are ongoingly focused on enhancing surgical methods and implant design._x000D_ Although osseointegration has a lot of potential, not all amputees may be good candidates for it. Considerations for osseointegrated implantation must take into consideration elements including the degree and nature of the amputation, the quality and density of the bone, and the desires of the patient.
In this study a Nickel-Titanium-Cupper shape memory alloys was manufactured by powder metallurgy (PM) technique, powder mixture of 50% Ti , 47% Ni and 3% Cu was prepared by mixing for two hours and compacted in a press machine using various compacting pressure (600, 700 and 800) MPa , sample was then sintered for 5 hrs in an electrical tube vacuum furnace using sintering temperature of (850?C, 900?C and 950?C) .phase analysis of samples was conducted by X-ray diffraction test, the effect of different sintering temperature and compacting pressure on the porosity, microhardness ,compression strength and the shape memory effect (SME) was studied, the result showed decrease in the porosity and increasing in the shape recovery ,compression strength and microhardness with increasing compacting pressure and at lower sintering temperature and hence the best results was at 800MPa compacting pressure and 850?C sintering temperature.
The objective of this paper is to develop an efficient P-wave detection algorithm based on the morphology characteristics of arrhythmias using time domain analysis.ECG from normal subjects, and patients with atrial fibrillation were studied. After baseline wander cancellation, power line interference filtration, the step of QRS detection using the pan- Tompkins algorithm is utilized to calculate R peak which represent the reference point to detect P peak.The algorithm was tested with experiments using MIT-BIH arrhythmia database which included Paroxysmal Atrial Fibrillation PAF prediction challenge, Massachusetts Institute of Technology MIT-BIH normal sinus rhythm, long term Atrial Fibrillation AF and MIT-BIH atrial fibrillation where every P-wave was extracted.The results reveal that the algorithm is accurate and efficient to detect and classify arrhythmias resulted from atrial fibrillation.