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Öğe A comparative performance evaluation for hybrid parallel adders in terms of delay, area, power, and energy(Gazi Univ, Fac Engineering Architecture, 2023) Avcl, Isa; Ozarpa, Cevat; Aydln, Muhammed AliIn the era of developing technology, faster applications in modern electronic systems increase the demands for less energy consumption, area, power, and delay. This research paper presents various classes of parallel adders and hybrid parallel adders in academic studies. In this study, hybrid parallel collector performance criteria for the delay, area, energy, and power consumption of the proposed models were investigated comparatively. In addition, the performance results of the hybrid parallel adder tools investigated in this study regarding certain criteria are shared. According to the comparative results obtained, hybrid parallel adder circuits with less delay, area, power, and energy consumption can be designed. By looking at these results, it will be possible to make hybrid model selections by considering the data in terms of collectors of the processors to be designed for the areas to be studied. The comparative results are given in Table 1. which shows the results obtained by the researchers by conducting experiments. In this research on hybrid parallel adders, bits of all lengths were generally tried to be considered. According to the research on these parallel adders, the experimental results of hybrid parallel adders in terms of different delay, area, power, and energy are brought together and their comparative analyzes are given.Öğe Dynamics of perforated higher order nanobeams subject to moving load using the nonlocal strain gradient theory(Techno-Press, 2021) Abdelrahman, Alaa A.; Esen, Ismail; Ozarpa, Cevat; Shaltout, Ramy; Eltaher, Mohamed A.; Assie, Amr E.The goal of this manuscript is to develop a nonclassical size dependent model to study and analyze the dynamic behaviour of the perforated Reddy nanobeam under moving load including the length scale and microstructure effects, that not considered before. The kinematic assumption of the third order shear deformation beam theory in conjunction with modified continuum constitutive equation of nonlocal strain gradient (NLSG) elasticity are proposed to derive the equation of motion of nanobeam included size scale (nonlocal) and microstructure (strain gradient) effects. Mathematical expressions for the equivalent geometrical parameters due to the perforation process of regular squared pattern are developed. Based on the virtual work principle, the governing equations of motion of perforated Reddy nanobeams are derived. Based on Navier's approach, an analytical solution procedure is developed to obtain free and forced vibration response under moving load. The developed methodology is verified and checked with previous works. Impacts of perforation, moving load velocity, microstructure parameter and nonlocal size scale effects on the dynamic and vibration responses of perforated Reddy nanobeam structures have been investigated in a wide context. The obtained results are supportive for the design of MEMS/NEMS structures such as frequency filters, resonators, relay switches, accelerometers, and mass flow sensors, with perforation.Öğe Dynamics of perforated nanobeams subject to moving mass using the nonlocal strain gradient theory(Elsevier Science Inc, 2021) Abdelrahman, Alaa A.; Esen, Ismail; Ozarpa, Cevat; Eltaher, Mohamed A.In the present manuscript, based on the nonlocal strain gradient theory, a nonclassical dynamic finite element model is developed to study and analyze the dynamic behavior of perforated nanobeam structures under moving mass/load. In the context of nonclassical continuum mechanics and Timoshenko beam theory, dynamic equations of motion of perforated nanobeams are derived including both size scale (nonlocal) and microstructure (strain gradient) effects. The modification of the geometrical parameters due to the perforation process is included in the equations of motion for squared holes arranged in the arrayed form. The effect of the moving mass (the inertia, Coriolis and centripetal forces, and the gravity force) or moving load are included in the proposed model. To remove shear locking problem in slender nanobeams, finite element model on nonclassical shape function basis is developed. Elements stiffness and mass matrices and force vector including the nonlocal and strain gradient effects are derived. The proposed model is verified and checked with previous works. Impacts of perforation, mass/load velocities, inertia of mass, microstructure parameter and nonlocal size scale effects on the dynamic and vibration responses of perforated nanobeam structures have been investigated in a wide context. The following model is beneficial for the design of MEMS/NEMS structures such as frequency filters, resonators, relay switches, accelerometers, and mass flow sensors, with perforation. (c) 2021 Elsevier Inc. All rights reserved.Öğe Free vibration of a cracked FG microbeam embedded in an elastic matrix and exposed to magnetic field in a thermal environment(Elsevier Sci Ltd, 2021) Esen, Ismail; Ozarpa, Cevat; Eltaher, Mohamed A.A mathematical model is developed, though this article, to investigate a vibrational behaviour of functionally graded (FG) cracked microbeam rested on elastic foundation and exposed to thermal and magnetic fields. The model includes a size scale effect and temperature dependent material properties, for the first time. The crack is modelled as a rotating spring, that is connecting the two parts of the microbeam at the crack's position. The equation of motion of the FG microbeam is obtained by using the Euler-Bernoulli beam theory for kinematic assumption and nonlocal elasticity theory for size- dependency effects. The transverse Lorentz force induced from the magnetic field is derived using Maxwell's equations. By adding the effects of thermal loading and foundation parameters on the cracked micro beam, the motion equation of the entire system is obtained using the Hamilton's principle and then solved with a Navier type solution method. Eight constraints equations are used to derived the frequency equation, which are boundary conditions at the end points and the displacement, slope, bending moment and transverse force continuity in the section where the crack is located. The resulting system of equations is solved sequentially, and natural frequencies and vibration modes of the cracked microbeam are obtained. The model is verified with previous published work. Numerical results are presented to illustrate influences of temperature, material composition, foundation parameters and magnetic field on the dynamics of the cracked FG microbeam.Öğe Impact of Covid-19 Pandemic on Smart Natural Gas Grids and Infrastructure Companies(Springer International Publishing Ag, 2022) Ozarpa, Cevat; Avci, Isa; Kinaci, Bahadir Furkan; Yetik, Hamza; Arapoglu, SuatThe global economy was adversely affected due to the contraction in international trade volume during the epidemic. The health systems of many countries are on the verge of collapse. In the study, phone calls were made with the managers of 5 companies providing natural gas and mechanical infrastructure services in Istanbul, and the multi-criteria decision-making method was used. As a result of the findings, it was determined that companies operating simultaneously in many sectors with different customer types were not affected by the epidemic. In contrast, companies serving individual customers in a single area were negatively affected by the Covid-19 global epidemic, and one of the companies stopped its activities. While there is no shrinkage in industrial customers' demands, companies serving only individual customers faced great challenges. This study aims to determine how the Covid-19 global epidemic affects companies providing natural gas and mechanical infrastructure services in Turkey. In this context, from the study, it was concluded that companies operating in the mechanical and natural gas infrastructure sector, which concentrate on a single field, were adversely affected by the global epidemic.Öğe Investigation of corrosion behavior of boron carbide reinforced AA7075 powder composites(Elsevier Science Sa, 2023) Kara, Seyit Ali; Ozarpa, Cevat; Esen, Ismail; Ahlatci, Hayrettin; Turen, YunusThis study was carried out in order to provide an example for the composite materials produced using powder metallurgy, which is frequently employed in the automotive and aerospace fields. In this study, powder metal matrix composite specimens were produced by using unreinforced AA7075 alloy, 10%B4C reinforced AA7075 alloy and 20% B4C reinforced AA7075 alloy with powder metallurgy method. The density of AA7075 is 2.78, the density of %10 B4C + AA7075 is 2.67, the density of %20 B4C + AA7075 is 2.62 g/cm3. The hardness value of the unreinforced AA7075 samples was 45.56 before the heat treatment and 63.2 after the heat treatment; the hardness value of the 10% B4C reinforced AA7075 sample was 79.42 before the heat treatment and 87.24 after the heat treatment; and the hardness value of the 20% B4C reinforced AA7075 sample was 95.34 before the heat treatment and 102 after the heat treatment. Corrosion resistance of composites was investigated with potentiodynamic polarization. As a result of the corrosion test, the best corrosion resistance was measured in the 20% B4C reinforced AA7075 sample, and the lowest corrosion resistance was measured in the unreinforced AA7075 sample.Öğe Investigation of fatigue life of draw hook equipment used in freight wagon: Miscellaneous result(Pergamon-Elsevier Science Ltd, 2024) Kinaci, Bahadir Furkan; Botsali, Huseyin; Ozarpa, Cevat; Esen, Ismail; Ahlatci, HayrettinThe coupling set, exposed to multi-directional severe dynamic loads, is a vital part that connects the wagons in rail system vehicles. These loads are usually transferred through the hook body in the draw hook coupler variant. Recently, some researchers have suggested that draw hook equipment suffers from fatigue damage if periodic maintenance is not performed correctly. For this reason, transportation safety is in danger. This study investigated fatigue occurring in the draw hook body and other metallurgical and mechanical properties affecting fatigue experimentally and numerically. The microstructure characterisation of the material was made using optic microscopy, electron spectrometry and scanning electron microscopes. The Brinell hardness and tensile test examined the material's mechanical properties. The fatigue behaviour rotating bending test and the complex S-N curves were obtained. For the computer validation of fatigue behaviour, stress life and strain life fatigue analyses were carried out using a commercial ANSYS program package. The high and low cycle fatigue regions are highlighted in the S-N curves. The endurance limit for the stress of 424.6 MPa was determined at 1.3 x 107 cycles.Öğe Investigation on the mechanical properties of X42N, grade A and grade B steel pipes joined by shielded metal arc and TIG welding(Gazi Univ, Fac Engineering Architecture, 2023) Ozarpa, Cevat; Akkus, Ahmet; Kinaci, Bahadir FurkanPurpose: The aim of this study is to investigate the effect the joining method on the mechanical properties of X42N, grade A and grade B pipes joined by TIG welding and shielded metal arc welding methods. Theory and Methods: The samples that were found the successful in the radiographic examination were then subjected to nick break, root bend, macro structure and hardness tests according to the API 1104 standard. The strength of the material against the applied impact was examined with the nick break and root bend tests. With the macro structure analysis, the joint conditions and material amounts in the weld area were examined. Results: All specimens passed root bending tests. In the notched fracture test, the X42N pipe, which was joined by shielded metal arc welding, was broken in the weld zone while the other 5 specimens were broken from the base metal. In macrostructural examination, it was determined that the welding zone was no defect, the weld penetration was good, there were no discontinuities and defects in the base metal and weld zone. Hardness measurements revealed that the hardness was increased both in the HAZ and in the weld zone due to the heat input during welding. Conclusion: It was shown the TIG welding method adopted on all materials yielded successful joints when compared with the shielded metal arc welding method. The X42N pipe was broken in the welding zone when the shielded metal arc welding method was applied. This shows that the mechanical properties of X42N pipe are superior to that for grade A and grade B pipes.Öğe Mitigating global warming in smart energy grids via energy supply security for critical energy infrastructures(Inderscience Enterprises Ltd, 2021) Avci, Isa; Ozarpa, Cevat; Aydin, Muhammed AliProblems in energy supply security threaten smart grids and cities, critical infrastructures and industrial control systems, and directly affect the economy. This study aims to examine the increase in energy supply, energy supply security risks, global warming, the importance of renewable energy sources, and environmental factors in energy infrastructure security. Also, a security framework has been proposed for critical energy infrastructures such as electricity, water, natural gas, coal, oil, renewable energy, and nuclear energy sources, taking into account the key risk factors of energy supply security and environmental impact sources. In the proposed framework, 17 different types of risks have been defined due to the reasons for natural gas, electricity, coal, oil, nuclear, and renewable energy sources. Risks concerned energy supply security and environmental impacts are calculated according to energy sources and it is determined that renewable energy sources have less risk (9%) than other energy types, electricity (13%) and natural gas (15%).Öğe Modelling the dynamics of a nanocapillary system with a moving mass using the non-local strain gradient theory(Wiley, 2020) Ozarpa, Cevat; Esen, IsmailIn this study, the dynamic behaviour of a Timoshenko nanobeam (a nanocapillary system) exposed to a moving mass is modelled by using the non-local strain gradient theory. Equations of motion of the Timoshenko nanobeam exposed to the moving mass are obtained by considering the strain gradient elasticity effect that provides toughening and the non-local elasticity effects that provide softening. These equations are converted to the weak form finite element equation by applying the full shape functions of the two-node Timoshenko beam element together with the Galerkin's method. The effects of the amount of different non-local parameters and the mass ratio and velocity of the moving mass on the dynamics of the nanobeam are presented. The frequency change of the nanotube due to the interaction with the moving mass is highlighted, and it has been shown that when the effect of the mass considered, the fundamental frequency has dropped about 55% when the mass ratio of the moving mass and the beam is 0.5. Moreover, the amount of the velocity and the mass of the moving load change the dynamic response of the tube.Öğe A Novel Technique for Identification of Wear Values at Different Lengths after Multiple Clinical Use of Different File Systems(Mdpi, 2022) Cirakoglu, Neslihan Yilmaz; Cicek, Ersan; Ozarpa, Cevat; Ozbay, Yagiz; Ozdemir, OlcayIntroduction The purpose of this research is to assess the wearing of the rotary file system (Protaper Next) and reciprocating file systems (Reciproc Blue and WaveOne Gold) at different lengths using a novel technique after in vivo clinical use. Materials and Methods Twelve different unused samples from each brand were accepted as reference values. For three different brands, the diameters of the files were measured by taking 12 samples used once, 12 samples used twice, and 12 samples used three times. Images were taken with a USB Micron Microscope, and file diameters were measured by determining limit values with Autocad. Result Reciproc Blue system was the most worn at apical 1 mm, and WaveOne Gold system was the most worn at apical 3 mm. PTN system exhibited the least wearing at any length. Moreover, less wearing was observed in the rotation motion than in the reciprocating motion. Conclusion In clinical practice, for the guttapercha to be fully adapted to the apical construction prepared according to the determined WL, the file should not undergo any wearing and volume reduction. Wearing-especially in the apical parts of the file-causes less preparation, and this situation could lead to apically obturation failure.Öğe Safety Calculation Model of Grade Crossings with Automatic Barrier System(Univ Osijek, Tech Fac, 2023) Kinaci, Bahad Furkan; Ozarpa, CevatRail transportation systems are among the types of transportation that are used extensively for reasons such as transportation safety and efficient structure. One of the most important parameters in rail transportation systems is the infrastructure systems used. Infrastructure systems used in areas where rail system lines intersect with highway systems can be listed as underpasses, overpasses, and grade crossings (GC). Although their use is risky, grade crossings continue to be used because underpasses and overpasses cannot be established for all intersections. Among the grade crossings, automatic barrier grade crossings appear as the safest structures. When grade crossings with automatic barriers are examined, it is observed that different parameters affect safety, and it is possible to make predictions for crossing safety. It has been observed that basic grade crossing features, location, physical structure, human and environmental factors, and signboards are effective while performing the safety assessment. In this study, the safety calculation model created for the safety calculation of grade crossings with automatic barriers has been transferred.
