PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8650
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Article Citation - WoS: 1Citation - Scopus: 1A Novel Hole Performance Index To Evaluate the Hole Geometry and Drilling Time in the Electrochemical Drilling Process(Public Library Science, 2024) Tosun, N.; Ozerkan, H. B.; Cogun, C.; Cep, RobertElectrochemical Drilling (ECD) is an unconventional method aimed at creating holes in metallic workpieces characterized by high hardness and complex structures. This study analyzes the influence of process variables, including machining voltage, electrolyte concentration, electrode rotational speed, electrolyte flushing pressure, and workpiece material, on the novel hole performance index (HPI) in electrical discharge machining (ECD). The HPI was identified as a suitable metric for simultaneously evaluating hole geometry and drilling time across various machining parameters and workpiece materials. The analysis of variance (ANOVA) method was employed to determine the significance of each machining parameter and workpiece material on the HPI. The research employed signal-to-noise ratio analysis to identify the optimal machining parameters. The findings demonstrated that the workpiece material and machining voltage were significant factors influencing HPI. The validation tests demonstrated that the proposed statistical method can significantly reduce HPI.Article Citation - WoS: 1Citation - Scopus: 1A Novel Fractional Model for the Projection of Households Using Wealth Index Quintiles(Public Library Science, 2022) Javeed, Shumaila; Raza, Saqlain; Baleanu, Dumitru; Ahmad, ShakoorForecasting household assets provides a better opportunity to plan their socioeconomic activities for the future. Fractional mathematical models offer to model the asset-holding data into a piece of scientific evidence in addition to forecasting their future value. This research focuses on the development of a new fractional mathematical model based on the wealth index quintile (WIQ) data. To accomplish the objective, we used the system of coupled fractional differential equations by defining the fractional term with the Caputo derivative and verified it with the stability tests considering the steady-state solution. A numerical solution of the model was obtained using the Adams-Bashforth-Moulton method. To validate the model, we used real-time data obtained from the household series of surveys in Punjab, Pakistan. Different case studies that elucidate the effect of quintiles on the population are also presented. The accuracy of results between real-world and simulated data was compared using absolute and relative errors. The synchronization between the simulated results and real-time data verifies the formulation of the fractional WIQ model. This fractional model can be utilized to predict the approximation of the asset-holding of the households. Due to its relative nature, the model also provides the opportunity for the researchers to use the WIQs of their respective regions to forecast the households' socioeconomic conditions.Article The first observation of memory effects in the infrared (FT-IR) measurements: Do successive measurements remember each other?(Public Library Science, 2014) Nigmatullin, Raoul R.; Osokin, Sergey I.; Baleanu, Dumitru; Al-Amri, Sawsan; Azam, Ameer; Memic, AdnanOver the past couple of decades there have been major advances in the field of nanoscience and nanotechnology. Many applications have sprouted from these fields of research. It is essential, given the scale of the materials, to attain accurate, valid and reproducible measurements. Material properties have shown to be a function of their size and composition. Physiochemical properties of the nanomaterials can significantly alter material behavior compared to bulk counterparts. For example, metal oxide nanoparticles have found broad applications ranging from photo-catalysis to antibacterial agents. In our study, we synthesized CuO nanoparticles using well established sol-gel based methods with varying levels of Ni doping. However, upon analysis of measured infrared data, we discovered the presence of quasi-periodic (QP) processes. Such processes have previously been reported to be tightly associated with measurement memory effects. We were able to detect the desired QP process in these measurements from three highly accurate repetitive experiments performed on each Ni (1-7%) doped CuO sample. In other words, successive measurements performed in a rather short period of time remember each other at least inside a group of neighboring measurements.Article Citation - WoS: 37Citation - Scopus: 46Dynamic Linkages Between Renewable Energy, Carbon Emissions and Economic Growth Through Nonlinear Ardl Approach: Evidence From Iran(Public Library Science, 2021) Karimi, M. S.; Ahmad, S.; Karamelikli, H.; Dinc, D. T.; Khan, Y. A.; Sabzehei, M. T.; Abbas, S. Z.This study examines the relationship between economic growth, renewable energy consumption, and carbon emissions in Iran between 1975-2017, and the bounds testing approach to cointegration and the asymmetric method was used in this study. The results reveal that in the long run increase in renewable energy consumption and CO2 emissions causes an increase in real GDP per capita. Meanwhile, the decrease in renewable energy has the same effect, but GDP per capita reacts more strongly to the rise in renewable energy than the decline. Besides, in the long run, a reduction of CO2 emissions has an insignificant impact on GDP per capita. Furthermore, the results from asymmetric tests suggest that reducing CO2 emissions and renewable energy consumption do not have an essential role in decreasing growth in the short run. In contrast, an increase in renewable energy consumption and CO2 emissions do contribute to boosting the growth. These results may be attributable to the less renewable energy in the energy portfolio of Iran. Additionally, the coefficients on capital and labor are statistically significant, and we discuss the economic implications of the results and propose specific policy recommendations.Article Citation - WoS: 8Citation - Scopus: 10The First Observation of Memory Effects in the Infrared (ft-Ir) Measurements: Do Successive Measurements Remember Each Other(Public Library Science, 2014) Osokin, Sergey I.; Baleanu, Dumitru; Al-Amri, Sawsan; Azam, Ameer; Memic, Adnan; Nigmatullin, Raoul R.Over the past couple of decades there have been major advances in the field of nanoscience and nanotechnology. Many applications have sprouted from these fields of research. It is essential, given the scale of the materials, to attain accurate, valid and reproducible measurements. Material properties have shown to be a function of their size and composition. Physiochemical properties of the nanomaterials can significantly alter material behavior compared to bulk counterparts. For example, metal oxide nanoparticles have found broad applications ranging from photo-catalysis to antibacterial agents. In our study, we synthesized CuO nanoparticles using well established sol-gel based methods with varying levels of Ni doping. However, upon analysis of measured infrared data, we discovered the presence of quasi-periodic (QP) processes. Such processes have previously been reported to be tightly associated with measurement memory effects. We were able to detect the desired QP process in these measurements from three highly accurate repetitive experiments performed on each Ni (1-7%) doped CuO sample. In other words, successive measurements performed in a rather short period of time remember each other at least inside a group of neighboring measurements.Article Citation - WoS: 9Citation - Scopus: 32Investigation of Dual-Mode Microstrip Bandpass Filter Based on Sir Technique(Public Library Science, 2016) Mezaal, Yaqeen S.; Ali, Jawad K.In this paper, a new bandpass filter design has been presented using simple topology of stepped impedance square loop resonator. The proposed bandpass filter has been simulated and fabricated using a substrate with an insulation constant of 10.8, thickness of 1.27mm and loss tangent of 0.0023 at center frequency of 5.8 GHz. The simulation results have been evaluated using Sonnet simulator that is extensively adopted in microwave analysis and implementation. The output frequency results demonstrated that the proposed filter has high-quality frequency responses in addition to isolated second harmonic frequency. Besides, this filter has very small surface area and perceptible narrow band response features that represent the conditions of recent wireless communication systems. Various filter specifications have been compared with different magnitudes of perturbation element dimension. Furthermore, phase scattering response and current intensity distribution of the proposed filter have been discussed. The simulated and experimental results are well-matched. Lastly, the features of the proposed filter have been compared with other designed microstrip filters in the literature.Article Citation - WoS: 13Citation - Scopus: 15New Operational Matrices for Solving Fractional Differential Equations on the Half-Line(Public Library Science, 2015) Taha, Taha M.; Alzahrani, Ebrahim O.; Baleanu, Dumitru; Alzahrani, Abdulrahim A.; Bhrawy, Ali H.In this paper, the fractional-order generalized Laguerre operational matrices (FGLOM) of fractional derivatives and fractional integration are derived. These operational matrices are used together with spectral tau method for solving linear fractional differential equations (FDEs) of order. (0 < v < 1) on the half line. An upper bound of the absolute errors is obtained for the approximate and exact solutions. Fractional-order generalized Laguerre pseudo-spectral approximation is investigated for solving nonlinear initial value problem of fractional order.. The extension of the fractional-order generalized Laguerre pseudo-spectral method is given to solve systems of FDEs. We present the advantages of using the spectral schemes based on fractional-order generalized Laguerre functions and compare them with other methods. Several numerical examples are implemented for FDEs and systems of FDEs including linear and nonlinear terms. We demonstrate the high accuracy and the efficiency of the proposed techniques.Article Citation - WoS: 5Citation - Scopus: 6Towards a Process Management Life-Cycle Model for Graduation Projects in Computer Engineering(Public Library Science, 2018) Gulec, Ulas; Sopaoglu, Ugur; Yilmaz, Murat; Tasel, Faris SerdarGraduation projects play an important role in computer engineering careers in which students are expected to draw upon their knowledge and skills that were acquired since admission. To manage the activities of graduation projects, an iterative and incremental approach which aims continuous improvement is proposed as an alternative to a controversial delivery model. However, such integration brings up a set of challenges to be taken into account: e.g. multiple project deliveries, more labor-intensive effort from instructors, and ultimately continuous learning for all participants. One promising way to achieve such an integrated and continuous deployment velocity is to eliminate potential bottlenecks by giving student teams to receive early and continuous feedback. To this end, we propose a continuous feedback and delivery mechanism for managing the life-cycle of a graduation project through draft proposal, literature review, requirements gathering, design, implementation and testing which should produce intermediate outputs at predefined intervals. Most importantly, our approach makes it possible to quantify most of the activities involved in life-cycle process with various rubrics (i.e. measurement scales) that have been purposefully developed. The proposed model promotes the fact that all improvements should be monitored, evaluated and documented. The results of this study indicate that students who were managed using this approach produced better project deliverables and ultimately have delivered better and successful projects.Article Citation - WoS: 12Citation - Scopus: 33Investigation of New Microstrip Bandpass Filter Based on Patch Resonator With Geometrical Fractal Slot(Public Library Science, 2016) Mezaal, Yaqeen S.; Eyyuboglu, Halil T.A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of epsilon(r) = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d). Also, a full comparative study of this filter as compared with traditional square patch filter has been considered.Article Citation - WoS: 10Citation - Scopus: 34Wide Bandpass and Narrow Bandstop Microstrip Filters Based on Hilbert Fractal Geometry: Design and Simulation Results(Public Library Science, 2014) Mezaal, Yaqeen S.; Eyyuboglu, Halil T.; Ali, Jawad K.; Zhang, FuliThis paper presents new Wide Bandpass Filter (WBPF) and Narrow Bandstop Filter (NBSF) incorporating two microstrip resonators, each resonator is based on 2nd iteration of Hilbert fractal geometry. The type of filter as pass or reject band has been adjusted by coupling gap parameter (d) between Hilbert resonators using a substrate with a dielectric constant of 10.8 and a thickness of 1.27 mm. Numerical simulation results as well as a parametric study of d parameter on filter type and frequency responses are presented and studied. WBPF has designed at resonant frequencies of 2 and 2.2 GHz with a bandwidth of 0.52 GHz, -28 dB return loss and -0.125 dB insertion loss while NBSF has designed for electrical specifications of 2.37 GHz center frequency, 20 MHz rejection bandwidth, -0.1873 dB return loss and 13.746 dB insertion loss. The proposed technique offers a new alternative to construct low-cost high-performance filter devices, suitable for a wide range of wireless communication systems.