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Gazi University Journal of Science
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2147-1762
Published by Gazi Üniversitesi Homepage  [9 journals]
  • The Effect of Annealing Technique on ZnO Film Properties

    • Authors: Meryem POLAT GÖNÜLLÜ
      Abstract: ZnO films deposited on glass substrates by ultrasonically chemical spray pyrolysis technique have been investigated to establish the effect of the annealing technique on film properties. For this purpose, films have been exposed to standard thermal annealing and microwave annealing in an air atmosphere. It has been determined that the structural, morphological, compositional, and optical properties of the ZnO films correlate with each other. X-ray diffraction analyses have been revealed the highest crystallization level and changing preferred orientations for microwave annealed films. It has been identified that the optical band gap values of the films decreased from 3.27 eV to 3.23 eV and 3.21 eV after the standard and microwave thermal annealing, respectively. Scanning electron microscope images have been revealed homogeneous morphology at plan-view images of all films. Also, it has been determined that the root-like morphology from the higher magnification scanning electron microscopy images. Thicknesses of the films have been also determined from cross-sectional scanning electron microscope images as 1.04m, 0.92m, and 0.92m for ZnO, standard thermal annealed and microwave annealed ZnO films, respectively. Also, the O/Zn ratio revealed improved stoichiometry for annealed films according to as-deposited film for investigated regions. The dependence of photoluminescence intensity on annealing technique has also been investigated in the current study.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Structures of Spermatheca and Eggs of the Red Firebug, Pyrrhocoris apterus
           (L. 1758) (Heteroptera: Pyrrhocoridae), Based on Optical and Scanning
           Electron Microscopy

    • Authors: Selami CANDAN; Nurcan ÖZYURT KOÇAKOĞLU
      Abstract: In this study, spermatheca and eggs of Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae were examined by light microscope and SEM. The eggs have ~1.30 mm length and 0.94 mm width. Newly laid eggs turn from white to yellow as soon as embryonic differentiation. P. apterus egg surface shows polygonal (usually hexagonal and pentagonal) shapes. The eggs have pipe shaped 6-7 micropylar projections. The egg-burster which is a dark T-shaped or triangular pattern, explosive becomes visible when the embryo is well developed. The nimph, which has completed its embryonic development, comes out of the egg with peristaltic movements. The spermatheca of P. apterus consists of a bulb, a pump, a flange of pump, and duct. The morphology of the egg and spermatheca is useful for classification, because they show a great diversity among species and genera. 
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Carbon Dioxide Capture Properties of MgCl2 Templated Microporous Carbon
           from p-toluenesulfonic Acid

    • Authors: Ali Can ZAMAN
      Abstract: Herein, porous carbon materials were prepared using p-toluenesulfonic acid (TsOH) as a carbon source with (TsOH-STC) and without (TsOH-C) presence of MgCl2.6H2O. The products were evaluated in terms of CO2 (carbon dioxide) adsorption performance, texture and surface chemical structure. Both samples contain oxidized sulfur on their surface according to X-ray photoelectron spectroscopy (XPS). TsOH-STC has a 3D porous network, but TsOH-C consists of a dense structure. It was understood that TsOH-C is not suitable to be analyzed with N2 adsorption at cryogenic temperatures probably due to restricted access to narrow pores due to lack of external surface. The CO2 uptakes are 0.78 mmol g-1 for TsOH-C and 0.67 mmol g-1 for TsOH-STC at flue gas conditions (0.15 bar and 298 K) of coal fired power plants, which is a projection of ultramicropore (pores smaller than 0.7 nm) volume in 0.5 nm range. TsOH-C has CO2 uptake capacity of 2.21 mmol g-1 and TsOH-STC reaches 2.47 mmol g-1 at 1 bar at 298 K. Maximum CO2 adsorption enthalpy (Qst) value for TsOH-C is 24.9 kJ mol-1 and that of TsOH-STC is 25.7 kJ mol-1. IAST (ideal adsorbed solution theory) selectivities (CO2:N2 = 15:85) of the samples are 13.5 for TsOH-STC and 19.7 for TsOH-C at 1 bar. It was shown in this study that salt templating with MgCl2 does not influence ultramicroporosity development and provide moderate level CO2 capture performance. However, templating induces formation of supermicropores (micropores larger than 0.7 nm), large mesopores and macropores on TsOH derived carbons.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Spectroscopic and Quantum Chemical Studies on the Structure of
           3-chloro-2-{(2Z)-2-[1-(4 methoxyphenyl)ethylidene]hydrazinyl}pyridine

    • Authors: Tufan TOPAL
      Abstract: 3-chloro-2-{(2Z)-2-[1-(4-methoxyphenyl)ethylidene]hydrazinyl}pyridine (HL) was prepared and its structure elucidated by LC/MS-MS, 1H and 13C-NMR, UV-Vis, elemental analysis, FT-Raman and FT-IR. All theoretical calculations and optimized geometry were obtained from the 6-31G(d,p) basis set calculations. Calculated and scaled data of the molecule were compared with the observed FT-Raman and FT-IR spectroscopic data. The theoretical chemical shifts of the HL were performed in chloroform by using the same level with the GIAO method. The UV-Vis analyses of the HL were carried out at three different concentrations in chloroform and ethanol solvents and between 240-440 nm; the calculations of UV-Vis spectra analyses were performed via the TD-DFT method. The charge transfer and hyperconjugative and conjugative interactions were analyzed using the NBO analysis. Furthermore, frontier molecular orbitals (FMOs) and molecular electrostatic potential (MEP) were also measured using the same method. This work provides a comprehensive electronic properties, vibration analysis and structural information of the title compund.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Combination of the Bipolar Soft Set and Soft Expert Set with an
           Application in Decision Making

    • Authors: Orhan DALKILIÇ; Naime DEMİRTAŞ
      Abstract: In this paper, we propose a novel concept of the bipolar soft expert set by combining the soft expert set and the bipolar soft set. Then, we define its basic operations such as complement, union, intersection, AND and OR for bipolar soft expert sets with illustrative examples. Then, using this set theory, an algorithm is proposed to express an uncertainty problem in the best way. Finally, we exemplify an uncertainty problem on how the proposed algorithm can be applied against uncertain situations that may be encountered in any field and we give its implementation in detail.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Investigation of Microwave Drying of a Firefighting Hose

    • Authors: Merve DAĞLI; Soner ÇELEN
      Abstract: The hoses used for fire extinguishing must be dried and stored after use in order to be cleaned, maintained and long-lasting. For this purpose, microwave energy which is a fast drying technology, was applied at power values of 2450 MHz and 120 W, 350 W and 460 W. The aim here is to dry the hoses quickly and show the effect of microwave energy by looking at SEM images and taking thermal photographs. In addition to it, nine drying models were compared with each other in order to determine the moisture content of the hose. The performances of these models were compared according to the correlation coefficient value (r), the estimated standard error (es) and the sum of squares of the residuals (χ2). According to the results, it was determined that the Logarithmic model for all drying conditions explains the drying behavior of the products better than the others. In addition, the effect of microwave drying did not cause a change on the internal structure of the sample but in consequence of thermal analysis, a fast rising was observed in the sample’s temperature with the energy rise.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Robust Group Identification and Variable Selection in Sliced Inverse
           Regression Using Tukey's Biweight Criterion and Ball Covariance

    • Authors: Ali ALKENANİ
      Abstract: The SSIR-PACS is a group identification and a model-free variable selection method under sufficient dimension reduction (SDR) settings. It combined the Pairwise Absolute Clustering and Sparsity (PACS) with sliced inverse regression (SIR) methods to produce solutions with sparsity and the ability of group identification. However, the SSIR-PACS depends on classical estimates for dispersion and location, squared loss function, and non-robust weights for outliers. In this paper, a robust version of SSIR-PACS (RSSIR-PACS) is proposed. We replaced the squared loss by the criterion of Tukey's biweight. Also, the non-robust weights to outliers, which depend on Pearson’s correlations, are substituted with robust weights based on recently developed ball correlation. Moreover, the estimates of the mean and covariance matrix are substituted by the median and ball covariance, respectively. The RSSIR-PACS is robust to outliers in both the response and covariates. According to the results of simulations, RSSIR-PACS produces very good results. If the outliers are existing, the efficacy of RSSIR-PACS is considerably better than the efficacy of the competitors. In addition, a robust criteria to estimate the structural dimension d is proposed. The RSSIR-PACS makes SSIR-PACS practically feasible. Also, we employed real data to demonstrate the utility of RSSIR-PACS.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Investigation of Laser Polishing on the Surface of the Parts Produced
           Using Powder Bed Fusion

    • Authors: Safak NESLİ; Oğuzhan YILMAZ
      Abstract: Additive manufacturing (AM) offers high design flexibilities and challenging approaches to produce highly complicated and intricate parts, which could not be possible to be produced with traditional manufacturing methods. However, one of the significant drawbacks of AM processes is, certainly, poor surface qualities, which are not acceptable for end products. Laser polishing (LP) offers an innovative surface-finishing technique that could be used to reduce the surface roughness. This research presents the fundamentals of the LP process, experiments on the additive manufactured part surfaces and the roughness reduction. An INCONEL 625 part produced by selective laser melting (SLM) was selected as the sample for the LP experiments. The results showed that laser polishing is able to enhance the surface finish and the reduction in surface roughness can become from Ra = 10.91 µm to Ra = 2.347 µm.  
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Some fixed point results via γ-contraction in non-Archimedean fuzzy
           metric spaces

    • Authors: Müzeyyen SANGURLU SEZEN
      Abstract: As other authors have been very interested in the topic of fixed points, we have obtained some results in this study that emphasize the importance of the fixed point theory. Kannan described a more general contraction than the Banach contraction that took its name and later Reich generalized this contraction further in metric spaces. In this paper, we have introduced some new contractions called Reich type γ-contraction and Kannan type γ-contraction which are generalization of γ-contraction and we have obtained some fixed point results for Reich type γ-contraction in non-Archimedean fuzzy metric spaces. We have presented a result about Kannan type-contraction. Furtermore, we have established an example about our main result.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • A New Multi-Target Compiler Architecture for Edge-Devices and Cloud
           Management

    • Authors: Erhan GÖKÇAY
      Abstract: Edge computing is the concept where the computation is handled at edge-devices. The transfer of the computation from servers to edge-devices will decrease the massive amount of data transfer generated by edge-devices. There are several efficient management tools for setup and connection purposes, but these management tools cannot provide a unified programming system from a single source code/project. Even though it is possible to control each device efficiently, a global view of the computation is missing in a programming project that includes several edge-devices for computation and data analysis purposes, and the devices need to be programmed individually. A generic workflow engine might automate part of the problem using standard interfaces and predefined objects running on edge-devices. Nevertheless, the approach fails in fine-tuning each edge-device since the computation cannot be moved easily among devices. This paper introduces a new compiler architecture to control and program edge-devices from a single source code. The source code can be distributed to multiple edge-devices using simple compiler directives, and the transfer and communication of the source code with multiple devices are handled transparently. Fine-tuning the source code and code movement between devices becomes very efficient in editing and time. The proposed architecture is a lightweight system with fine-tuned computation and distribution among devices.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Design and Fabrication of Compact Microstrip Low-pass Filter with Thin
           Film Technique for Wideband Applications

    • Authors: Reşat TÜZÜN; Nursel AKÇAM, Tayfun OKAN
      Abstract: This paper introduces a compact microstrip low-pass filter (LPF) with a very sharp rejection. The proposed LPF is designed to be used for electronic warfare in defense industry. It has 62 dB/GHz attenuation rate, 10 GHz of stopband width and 48.6 dB of stopband attenuation. Moreover, it also has a wide passband and has a high cut-off frequency (f_c) of 6 GHz. The designed filter has been fabricated using alumina (Al2O3) substrate and titanium-gold (Ti-Au) coating on top of that with thin film technique in a clean room. The experimental measurements of the proposed LPF show great agreement with the simulation results, which validates that the presented filter is convenient to be used for applications up to C-band in electronic warfare systems.  
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Wind Speed Analysis for Coastal Regions of Pakistan using Extended
           Generalized Lindley Distribution

    • Authors: Rana USMAN; Muhammad AHSAN-UL-HAQ, Nurbanu BURSA
      Abstract: The wind energy potential of a specified area can be estimated using wind speed distribution. In this study, the selection of probability density functions is used to model wind speed data recorded at two stations in Pakistan. The suitability of fitted distributions is evaluated using the goodness of fit criterion, power density error, log-likelihood, root mean square error, coefficient of determination, AIC, and BIC. The wind speed data are obtained from two coastal regions of Pakistan at 10m/s average rate for session 2017-2018. Findings indicated that the extended generalized Lindley distribution provide generally the best fit to the wind speed data for both stations. However, it is also observed that power Lindley and extended generalized Lindley distributions have better performance based on power density error criteria in Gwadar and Haripur, respectively. 
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Investigation of Thermomechanical Processing of Nb Microalloyed Steel
           Produced by Powder Metallurgy

    • Authors: Demet TAŞTEMÜR; Süleyman GÜNDÜZ, Mehmet Akif ERDEN
      Abstract: One of the most important properties of microalloyed steels is the different microstructures which are obtained by changing the thermomechanical processing parameters and steel composition. The control of microstructure such as grain size, precipitates, dislocation structure and inclusions are highly effective to determine the mechanical properties of microalloyed steels. The strengthening of mechanical properties can be done by thermomechanical processesing due to increase of nucleation sides via maximizing the austenite boundary and density of the deformation band. In this study, the unalloyed steel and microalloyed steel containing 0.15% Nb were produced by powder metallurgy and hot deformed to reduce the thickness by 40% and 75%. EDX analyzes, density, hardness and grain size measurements were also performed on specimens. According to the SEM microstructure results, the grain size gradually decreased with respect to the deformation rate in both steels. It was observed that small grains occurred due to a complete recrystallization process at 75% deformation rate which were supported by grain size analysis. The density and hardness values increased by the increase in deformation rate. While the density and hardness of microalloy steel under sintered conditions was 89.46% and 75 Hv, respectively, 75% deformed condition was 98.51 % and 231 Hv.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • A Fuzzy Logic Approach on the Evaluation of Driving Styles and
           Investigation of Drivability Calibration Effects

    • Authors: Samet AKSIT; Akif YAVUZ, Osman Taha ŞEN
      Abstract: Increased customer expectations lead the automobile manufacturers to develop innovative solutions, such as mode selection functions that provide different performance and comfort settings for the drivers. Almost all brands have different types of driving modes installed on their vehicles, such as sport mode, economy mode, off-road mode, etc. In the current technology, the mode selection is manually done by the driver. Thus, no effort is taken to match the driver style with available driving modes. However, driving mode selection should be done through an intelligent system such as vehicle control unit, in order to optimize customer expectations related to vehicle performance, driving comfort, and fuel consumption. This can be achieved by the analysis of all drivability maneuvers during any driving cycle. Based on the results of these analyses, drivability calibration settings of the vehicle can be adjusted depending on driver behaviors. In addition, fuel consumption can be improved using suitable calibration for each driver type. In this study, an experimental investigation is carried out in which vehicle data is collected for eleven different drivers at three different drivability calibrations. Furthermore, fuzzy logic algorithms are utilized in order to distinguish the driver characteristics. First, data from nine drivers are used in order to train the fuzzy logic approach. Then, the trained fuzzy logic scheme is used to assess the characteristics of two other drivers, who were left out in the training data set. Hence, it is aimed to obtain an intelligent prediction procedure that can estimate the characteristics of a driver based on their driving styles.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Parameter Estimation Methods and Applications of the Power Topp-Leone
           Distribution

    • Authors: Mohammed ELGARHY; Amal SOLİMAN, Heba NAGY
      Abstract: We display the power Topp-Leone (PTL) distribution with two parameters. The following major features of the PTL distribution are investigated: quantile measurements, certain moment’s measures, residual life function, and entropy measure. Maximum likelihood, least squares, Cramer von Mises, and weighted least squares approaches are used to estimate the PTL parameters. A numerical illustration is prepared to compare the behavior of the achieved estimates. Data analysis is provided to scrutinize the flexibility of the PTL model matched with Topp-Leone distribution.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Decolorization of Reactive Black 5 Using N-Doped TiO2

    • Authors: Aslı BERKTAŞ; Özlem Esen KARTAL
      Abstract: Decolorization of Reactive Black 5 (RB5) was investigated by heterogeneous photocatalysis using N-doped TiO2. N-doped TiO2 photocatalysts were synthesized by means of a sol-gel process. X-ray diffraction performed the characterization of synthesized samples, scanning electron microscopy and X-ray photoelectron spectroscopy measurements. Photocatalytic activity of N-doped TiO2 samples was assessed by following decolorization and degradation efficiency of RB5. N-TiO2(3) sample yielded the highest decolorization efficiency. The apparent first-order rate constants for decolorization of RB5 with N-TiO2(X) samples followed the order of N-TiO2(3) > N-TiO2(2) > N-TiO2(4) > N-TiO2(1). Improvement of decolorization efficiency of TiO2 was observed doping with nitrogen. The effect of actual sunlight on decolorization efficiency was also investigated. 96% and 49% of decolorization efficiency levels were attained within 60 minutes of reaction time with outdoor sunlight and fluorescent daylight lamps, respectively. 
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Development of a Hybrid Radio Frequency Identification (RFID) and
           Biometric Based Library Management System

    • Authors: Ayodeji OKUBANJO; Alexander OKANDEJİ, Ositola OSİFEKO, Ayoola ONASOTE, Mufutau OLAYEMİ
      Abstract: This paper presents a smart library management system based on the combination of RFID technology and biometric recognition system to improve the efficiency of conventional library management. In particular, the proposed design combines radio frequency identification (RFID) and Biometric technology to enhance user processing time, improve user service, curtail book theft, and maintain continuous update of new books and to further increase the biometric security of the system against an imposter. Using MySQL, internet of things (IoT), and Java programming, we design a system that provides the user with unrestricted access to online library facilities with a personal computer or mobile devices. For improved efficiency, the proposed design is integrated with an SMS and email alert notification system. The proposed design thus allows the user to access books and course materials from a remote location in an authenticated and secured manner. The system performance was compared with the manual method in terms of book positioning function, false rejection rate, false acceptance rate, counting efficiency, average time spent in booking searching and the result show that the proposed system outperforms the conventional (manual) library system
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Dimeric aza-BODIPY and Dichloro-aza-BODIPY: A DFT Study

    • Authors: Mehmet Emin ÇINAR
      Abstract: Density functional theory (DFT) computations were performed to unveil the electronic structures and the Kohn-Sham Molecular Orbitals (MOs) of the dimeric aza-BODIPY molecule and its chlorinated form. The optimized conformation of dimers is well in alignment with the one provided in the literature. The HOMO LUMO gap of dichloro-derivative is smaller than that of the dimeric aza-BODIPY molecule by 35.0 meV. The predicted HOMO energies of -6.40 and -6.60 eV point out the good stabilities of both compounds. They were reported to demonstrate bathochromic shifts of 40 and 57 nm compared to their monomers substituted by H and Cl, respectively. The intriguing photophysical behaviors of these molecules were investigated by conducting the Tamm-Dancoff density functional theory (TDA-DFT) calculations. The max values emerge from the HOMO-1 -> LUMO+1 (83-86%) transitions, whereas the low energy transitions arise from HOMO -> LUMO (89%). Therefrom predicted ELUMO->HOMO of the dimeric aza-BODIPY and dichloro-derivative are 1.89 and 1.87 eV, respectively, which are matching well with the reported literature values.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • An Efficient Hybrid Algorithm with Particle Swarm Optimization and
           Nelder-Mead Algorithm for Parameter Estimation of Nonlinear Regression
           Modeling

    • Authors: Aynur YONAR; Harun YONAR
      Abstract: Nonlinear regression analysis is an important statistical method widely used in many fields of science to model the complex relationships between variables. Therefore, many studies have been conducted to estimate the parameters of nonlinear regression models using various iterative techniques. In this study, an efficient hybrid algorithm, namely PSONM, by combining the exploration capability of Particle Swarm Optimization (PSO) and the exploitation capability of the Nelder-Mead (NM) algorithm is proposed to obtain parameter estimates of nonlinear regression models. To show the performance of the proposed hybrid algorithm, 20 nonlinear regression tasks with various levels of difficulty, and real data sets in the agriculture field have been tested. The experimental results indicated that the suggested hybrid algorithm provides accurate estimates, and its performance is much superior to those of NM and PSO algorithms.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Industrial Digitalization with Four Dimensional (4D) Printing - Novel
           Technology: Brief Review on Developments, Challenges and Applications

    • Authors: Reddy SREENIVASULU
      Abstract: The latest advances in additive manufacturing methods (AMM) generally called as three- dimensional (3D) printing permitted to design and generate complicated profiles which are not possible with regular fabrication methods. A branch of new fabrication technique initiated from three dimensional (3D) printing further it is called as four dimensional (4D) printing with self healing materials that can react to outer stimuli by subjecting external pressure on it. Also, day to day advancements in fashion in the lifestyle of public, industries are not capable to satisfy their requirements with conventional manufacturing techniques with conventional materials because of increased cost to alter the design, manufacture and process layout for each fashion style. It is impossible to satisfy with conventional materials as well as processing methods, so more competition existed in the present industrial sectors according to market demands as per customer requirements. Advancements in additive manufacturing techniques covered this gap by day-to-day developments in materials and their methods, provide a variety of designs and fabricate them with a short time by sustaining less investment. In this article, recent developments of smart materials discussed and innovations in 4D printing and challenges which are faced in the research and development divisions also described about a variety of application areas almost in all fields. This paper provides basic information data to the young researchers who are interested to do their work in this area and also discussed with the latest available data pertaining to 4D printing globally.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Performance Analysis of Burst Traffic Awareness Based Mobile Sink Routing
           Technique for Wireless Sensor Networks

    • Authors: Sercan YALÇIN; Ebubekir ERDEM
      Abstract: In wireless sensor networks (WSNs), it is vital to adopt a suitable mobile routing algorithm between sensor nodes and mobile sinks (MSs) for data gathering efficiently. In WSNs, random mobility of the MSs increases the mobile path length in the network when data traffic bursts. Therefore, the focus of this study is to overcome burst traffic in an energy-efficient way using the MSs in the network. In this study, a new burst traffic awareness adaptive mobile routing scheme based on heterogeneous WSNs has been developed. The network area is divided into two cluster groups in the proposed scheme, each with a certain number of clusters. In the network, a MS of each cluster group acts. The MSs gather all data in a single-hop attitude as soon as they arrive at the clusters. In this way, the energy load is distributed evenly among the network. Once a burst data is detected in the routing model, a MS updates its trajectory to the cluster head (CH) where the burst occurs. The performance results validate that the proposed methodology outperforms recent studies based on the network lifetime, average energy consumption, and average mobile path length. Also, the effect of the burst traffic situations on network efficiency is analyzed with simulation.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • A Symmetrical-Asymmetrical Fault Characteristics Analysis within
           Cogeneration Power Plant in Izmir, Turkey: An Experimental Assessment

    • Authors: Hacer OZTURA; Sezai POLAT
      Abstract: The analysis of the short circuit should be understood very well in order to make correct designs in the power systems such as the safety of the personnel and the equipment, the selection of the safety relays, the circuit breaker selection and the selection of the appropriate conductor section. In this study, the parameters about the short circuit and the techniques of calculating the faults in system and the necessary theoretical knowledge for the short circuit fault to be understood better have been given. The effect on the distributed generation and the grid which is caused by the possible short circuit faults have been simulated by being modeled in PSS/Sincal and by using the real grid parameters with cogeneration power plant in Izmir, Turkey. The real short circuit fault results measured from the power plant and the grid and the results obtained from the software program have been compared and it has been determined that there is not a significant difference between them. Thus, it has been emphasized that it is correct to simulate before investing in a power system in for the purpose of restrain the faults during the designing and working before the application. It allows the designer to design new power plant as good as plan expansion of existing power plants with higher degree of precision. Considering the prices of protection equipment, which has a large part in system design, this way would allow designer to reduce the cost of the protective equipment and remaining stability.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • A Comprehensive Thermophysiological Comfort Analysis of Breathable
           Membrane Laminated Fabrics

    • Authors: Çağlar SİVRİ
      Abstract: In this study, the comfort properties of water-proof but breathable (water vapour permeable) textile fabrics having the composite structure containing a membrane layer or a coating layer are examined. In the present study, parameters such as ambient conditions, the air gap between body and garment, thickness of materials used in the production of garments and composite structure affecting the comfort properties of the structures mentioned above were examined. After the selection and obtaining the samples; water vapour permeability, air permeability, waterproofness tests were respectively applied and the results were interpreted in a way that producers and related scientists could benefit. The most important results achieved here are that the water vapour permeability decreases as the thickness of the membrane/coating in which the fabrics are coated/laminated increases, the air gap between the body and the garment reduces the water vapour permeability greatly, the membrane character (microporous / non-porous) has different effects on the water vapour permeability in different ambient conditions. These results sound promising for future studies.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • An Effective Image Encryption Algorithm Using Bit Reversal Permutation and
           a New Chaotic Map

    • Authors: Hidayet OĞRAŞ; Mehmet Rıda TÜR
      Abstract: In this paper, a different approach to create a new chaotic model and an effective image encryption structure using Bit reversal permutation are proposed. Compared to most frequently used and well known chaotic maps, such as Logistic map, Sine map or Tent map, a new chaotic system based on Logistic map with Sine map is designed and used as an encryption key generator in the proposed algorithm. The new map has increased initial value sensitivity according to the results of Lyapunov analysis and shown better randomness output according to the chaotic trajectory analysis. In cryptography, a good key should be a stochastic and supposed to be sufficiently random and uniformly distributed with equal probability for an effective encryption. The designed chaotic map provides these properties very well. Before the basic encryption process, the Bit reversal method makes all pixel positions of input image rearranged in order to reduce the strong relation of adjacent pixels for higher encryption strength, which will enable strategic information sharing for production planning when this method analyzes a wind energy map in power plants. Other experimental results confirm that the proposed image encryption scheme has sufficient security, an effective encryption capability and can be transferred between power systems, keeping energy planning secret strategically. 
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Quantum dot Cellular Automata based Fault Tolerant Fingerprint
           Authentication Systems using Reversible Logic Gates

    • Authors: Suhaib AHMED; Syed NAZ, Sparsh SHARMA
      Abstract: The limits and difficulties looked by CMOS innovation in the nano system has prompted the exploration of other potential advancements which can work with same functionalities anyway with lower power scattering and higher speed. One such technology is Quantum dot Cellular Automata (QCA). In this paper, QCA is explored to design the authentication system. This paper first presents the basic operating principle of a Fingerprint Authentication System (FAS) followed by fault tolerance analysis of four efficient XOR gate designs in the literature. The XOR gate is then used in the proposed four fault tolerant designs of reversible FAS in QCA, which are based on different reversible gates. Based on the evaluation of different performance parameters, it is seen that the proposed FAS designs are cost efficient and achieve improvement up to 59.46% in terms of number of cells, 67.16% improvement in cell area, 67.14% improvement in total area, 66.67% improvement in latency and 90.51% improvement in terms of circuit cost from the existing design Furthermore, the energy dissipation examination of the proposed designs is also additionally introduced. Subsequently, the proposed designs can be effectively used in biometric applications demanding ultra-low power consumption, higher operating speed and minimal area utilization.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Direct Displacement Based Design for Reinforced Concrete Framed Structures
           with Seismic Isolation

    • Authors: Channabasaveshwar CHIKMATH; Ankit SODHA, Sandip VASANWALA
      Abstract: Direct displacement-based design is a nonlinear static procedure and has to check the suitability of the method against different types of ground motions namely far field, near field forward directivity and near field fling step. The method is applied for the buildings supported on a fixed base and hysteretic isolation bearings. Seismic isolators are provided between the foundation and the superstructure to minimize the influence of ground motion on the superstructure. The method is applied for four, eight and twelve storey reinforced concrete frame structures equipped with and without seismic isolators. Lead rubber bearing is used as seismic isolators. An equivalent damping ratio, derived from the particular characteristics of buildings supported on isolation bearings, is suggested. The energy dissipation mechanism in the isolators controls the displacement of the structure within acceptable limits at the level of the isolator. The results were validated with nonlinear time history analysis and were found to be in good agreement with the Direct displacement-based design methodology for far field ground motions. The performance of the building was measured for interstorey drift ratio, time period, acceleration of top floor, base shear, isolator displacement. This is an attempt to link the direct displacement-based design of the reinforced concrete building with seismic isolators subjected to the far field, near field forward directivity, near field fling step ground motions.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Best Proximity Point Results For Multivalued Cyclic Mappings On Partial
           Metric Spaces

    • Authors: Mustafa ASLANTAŞ
      Abstract: Let ∅≠Ŕ,Ś be subsets of a partial metric space (Ω,ϑ) and Ψ:Ŕ→Ś be a mapping. If Ŕ∩Ś=∅, it cannot have a solution of equation Ψς=ς for some ς∈Ŕ. Hence, it is sensible to investigate if there is a point ἣ satisfying ϑ(ἣ,Ψἣ)=ϑ(Ŕ,Ś) which is called a best proximity point. In this paper, we first introduce a concept of Hausdorff cyclic mapping pair. Then, we revise the definition of 0-boundedly compact on partial metric spaces. After that, we give some best proximity point results for these mappings. Hene, our results combine, generalize and extend many fixed point and best proximity point theorems in the literature as properly. Moreover, a comparative and illustrative example to demonstrate the effectiveness of our results has been presented.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Application of Grey Wolf Optimization Algorithm: Recent Trends, Issues,
           and Possible Horizons

    • Authors: Emmanuel DADA; Stephen JOSEPH, David OYEWOLA, Alaba Ayotunde FADELE, Haruna CHİROMA, Shafi'i Muhammad ABDULHAMİD
      Abstract: The development of Grey Wolf Optimisation (GWO) Algorithm was motivated by the biological behaviours of swarm of wolves hunting for prey. This paper presents recent progress on Grey Wolf Optimization (GWO) algorithm, its variants and their applications, issues, and likely prospects. The review revealed that opportunities still exists for development of more robust and stable variants of GWO that will overcome the shortcomings of existing variants. This review has the potential to stimulate researchers in the area of nature-inspired algorithms to further advance the effectiveness of the GWO and its ability to solve problems. Such problems can be real-life, complicated and nonlinear optimization problems in different domain of human endeavour. Suggestions for new research directions that have the capacity to increase the performance of GWO are presented. It is expected that this paper will serve as reading material for beginners whereas experienced researchers can also use it as an article yardstick for further development of GWO algorithms. 
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Theoretical Determination of Corrosion Inhibitor Activities of Naphthalene
           and Tetralin

    • Authors: Rebaz OMER; Pelin KOPARIR, Ibrahim QADER, Lana AHMED
      Abstract: Quantum mechanical methods were used to investigate the corrosion inhibitor activities of tetraline and naphthalene compounds. In this study, some parameters were estimated, including, the energy of the highest occupied molecular orbital (EHOMO), the energy of the lowest occupied molecular orbital (ELUMO), the energy bandgap (ΔE = ELUMO - EHOMO), and the dipole moment (μ). The aforementioned parameters give information about the corrosion efficiency of organic compounds. Furthermore, the density functional theory (DFT) was handled to determine the geometry of the molecules and electronic characteristics of the compounds. B3LYP/6-31G (d, p) was utilized to determine physical parameters such as hardness (ɳ), softness (σ), and electronegativity (χ). We also evaluated quantum chemistry characteristics including the fraction of electrons transported (ΔN) between the iron surface and our title compounds. This study also discusses which parameters have a significant linear relationship with inhibitory performance. The findings suggest that the behavior of organic-based corrosion inhibitors is correlated with the effectiveness of good corrosion inhibitors and the quantum chemical parameters measured from this process. As a result, the behavior of corrosion inhibitors can be determined without the need for an experiment.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
  • Statistically optimized adsorption of Pb(II) ion on Corn Husk activated
           carbon – An application of Response Surface Method

    • Authors: Agha Arslan WASİM; Muhammad NASIRUDDIN KHAN, Saba FAZAL-UR-REHAMAN
      Abstract: In this study, the Response Surface Method statistically optimized Pb(II) adsorption on activated carbon prepared using corn husk. The full central composite design was the statistical method selected for optimization using adsorption capacity as a response factor. The quadratic model best explained the process. Adsorption parameters optimized were solution pH, contact time, temperature, and adsorbent dose. The respective optimum values were 4.5, 64 min, 50°C, and 0.4 g L-1. Adsorption isotherm and kinetics studies evaluated the data obtained at different temperatures using different isotherm and kinetics models. The non-linear curve fitting method determined the model with the best fit. Freundlich’s model best accommodated the isotherm data, whereas the pseudo-second-order kinetic model best modeled the kinetics data. Weber-Morris intraparticle diffusion model revealed the existence of multiple rate-controlling processes. The activation energy for the adsorption of Pb(II) ions was 30.17 kJ mol-1. The thermodynamics studies showed that the process was an entropy-driven endothermic process. Gibb’s free energy (ΔG) values were negative at the studied temperatures, and the spontaneity increased with the increase in temperature. The enthalpy (ΔH) and entropy change (ΔS) was 43.78 kJ mol-1 and 154.2 J mol K-1. The study concluded that the statistical method simplified the optimization of the adsorption process and produced an efficient adsorbent from corn husk.
      PubDate: Wed, 01 Jun 2022 00:00:00 +030
       
 
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