Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Akkurt, Nevzat(15)
- Sayyed, M.I.(8)
- Askin, A.(6)
- Güler, Ömer(6)
- Yildirim, Ozal(6)
- Tekin, H.O.(5)
- Zengin, Gokhan(5)
- ALMisned, Ghada(4)
- Ak, Gunes(4)
- Aslan, Naim(4)
- Gul, Muhammet(4)
- Kök, Mediha(4)
- Lassabatere, Laurent(4)
- Paksoy, Mehmet Yavuz(4)
- Stewart, Ryan D.(4)
- Yilmaz, Deniz(4)
- Çimen, Okay(4)
- Abou Najm, Majdi R.(3)
- Ali, Shahbaz(3)
- Artuğer, Fırat(3)
- Baloglu, Ulas Baran(3)
- Bayrakdar, Cihan(3)
- Dere, Ayşegül(3)
- Di Prima, Simone(3)
- Erguven, Gokhan Onder(3)
- Ilik, E.(3)
- Karataş, Mehmet(3)
- Kavaz, E.(3)
- Kaya, Mehmet(3)
- Keserci, Ferhat(3)
- Kilic, G.(3)
- Mahomoodally, Mohamad Fawzi(3)
- Nadeem, Sohail(3)
- Rodrigues, Maria João(3)
- Serdar, Osman(3)
- Simonetti, Antonio(3)
- Talo, Muhammed(3)
- Xu, Qian(3)
- Zheng, Qiang(3)
- Çılğın, Zeynel(3)
Yayınlar
- MakaleYayıncıda açık erişim2023Scopus SJRQ1Geochemical and radiometric data for mafic rocks from the Guleman Ophiolite (SE, Turkey): New insights on the geodynamic evolution of the southern Neo-Tethyan ocean
Sapancı, Özgür; Tokat, Gürkan; Eraslan, Nuh Kadri; Karakaya, Abdullah Onur; Gücer, Mehmet Ali; Çimen, Okay
The Guleman Ophiolite is located in the southeast of Turkey and mainly consists of harzburgites and dunites hosting economically viable chromitite bodies, and lesser amounts of cumulate and isotropic gabbro, diabase dykes, pyroxenite and locally plagiogranite. This study reports the combined whole-rock geochemical and radiogenic isotope (Sr and Nd) data for gabbro and diabase dykes, and in-situ zircon U-Pb geochronological data for plagiogranite and gabbro from the Guleman Ophiolite. Two different geochemical groups were determined based on immobile minor and trace elements, and radiogenic isotope characteristics of gabbro and diabase dykes investigated here. The first group is represented by boninites and displays highly depleted elemental patterns compared to NMORB, and spoon-shaped rare earth element profiles. Contrarily, the second group resembles back-arc basin basalts and is characterized by NMORB-like rare earth element patterns associated with negative Nb anomalies. The boninitic samples are characterized by less radiogenic 143Nd/144Nd(i) (0.51229 to 0.51267; ƐNd = −4.8 to +2.7) and more radiogenic 87Sr/86Sr(i) (0.70549 to 0.70758) isotope compositions compared to the back-arc basin basalt-like samples (143Nd/144Nd(i) = 0.51289 to 0.51296; ƐNd = +7.0 to +8.4; 87Sr/86Sr(i) = 0.70496 to 0.70629), indicating derivation from distinct and/or heterogeneous mantle source regions within a supra-subduction zone. The LA–ICP–MS zircon U-Pb analyses yielded concordant late Cretaceous ages for gabbro (82 ± 2.9 Ma) and plagiogranite (79.9 ± 0.8 Ma) samples. The overall geochemical, isotopic and geochronological data presented here suggest that the Guleman Ophiolite consists of forearc and initial back-arc spreading sections of oceanic crust, which may have been formed in an intra-oceanic subduction zone within the Berit Ocean (northern branch of the southern Neo-Tethyan ocean). Moreover, the generation of continental arc magmatism (i.e. Baskil and Esence Granitoids) was well-documented on the active margin of the Malatya-Keban Metamorphics to the north. Therefore the closure of this oceanic basin should have resulted in multiple coeval northward subduction events during the late Cretaceous.
AtıfScopus8WoS7OpenAlex9
İncele - MakaleYalnız künye2023Scopus SJRQ1In-vitro corrosion and surface properties of PVD-coated β-type TNTZ alloys for potential usage as biomaterials: Investigating the hardness, adhesion, and antibacterial properties of TiN, ZrN, and CrN film
Ali, L.A.; Dikici, B.; Aslan, N.; Yilmazer, Y.; Sen, A.; Yilmazer, H.; Niinomi, M.
In this study, the corrosion and surface properties of non-toxic and non-allergenic β-type Ti–29Nb–13Ta–4.6Zr alloys (TNTZ) coated with TiN, ZrN, and CrN layers using the PVD technique were investigated under in-vitro conditions. The coatings' hardness, adhesion resistance, and antibacterial properties were also studied, with a focus on their potential usage as biomaterials. The corrosion tests were conducted using potentiodynamic polarization, the hardness tests were conducted using the Knoop method, and the adhesion tests were conducted using pull-off tests. The wetting properties of the coatings were examined through contact angle and 3D morphological analysis. The coatings were characterized using SEM-EDS and XRD. The results showed that the adhesion resistance of all coatings was significantly higher than the expected adhesion strength for biomaterial coatings, while their corrosion resistance was higher compared to the uncoated alloy. Besides, the study demonstrates the potential of TiN, ZrN, and CrN coatings on β-type TNTZ for use as a biomaterial with desirable surface and antibacterial properties.
AtıfScopus29OpenAlex27İncele - Derleme MakaleYalnız künye2023Scopus SJRQ1A review of advances in mechanical behaviors of the underground energy transmission pipeline network under loads
Zheng, Qiang; Xu, Qian; Shu, Zekai; Yang, Di; Chen, Weiwang; Akkurt, Nevzat; Zhang, Hui; Lin, Lin; Zhang, Xinxin; Ding, Yulong
The safety of underground energy transmission pipeline network is threatened by traffic, earthquakes, explosions, and other stresses. To solve the problem of damage to the underground energy transmission pipeline networks by external loads, this study analyzed the mechanical properties of the Pipe-Soil Coupling System (PSCS) under external loads from a mechanical perspective. The pipeline constitutive model, the soil constitutive model, the internal effect of the PSCS, the influence of external stresses on the PSCS, and the dynamic response of the PSCS under various research methodologies were all studied. First, different mechanical features of the pipes and soil were employed to investigate the pipe and soil constitutive models. Second, based on the different force directions within the PSCS, the earth pressure and axial friction of the PSCS were investigated to clarify the interaction between the pipe and soil. For the purpose of to better understand the degradation of the underground pipeline state, the impacts of man-made and natural stresses on the PSCS failure were explored. Finally, the results of the investigation of the dynamic response of the PSCS were examined for their applicability using three research methods: theoretical analysis, numerical simulation, and experimental analysis. It is found that the existing constitutive models of pipeline and soil are lack of basis, which increases the difficulty of the selection of constitutive models in the process of research. In the analysis of load effect, earth pressure plays a dominant role in affecting the local stability of pipeline, but the calculation accuracy of soil pressure needs to be improved. Due to the lack of experimental guidance for complex damage phenomena under external loads, it is impossible to accurately determine the limit state parameters of pipelines under complex damage modes. It is critical to create and refine the theory underpinned by numerous experimental data in order to address the issue of pipeline dynamic response under multi-field coupling, including explosion and earthquake. This work is critical for analyzing existing research findings, identifying future research problems, and enhancing buried pipeline safety management.
AtıfScopus15WoS13OpenAlex14İncele - MakaleYalnız künye2023Scopus SJRQ1A long short-term memory-based hybrid model optimized using a genetic algorithm for particulate matter 2.5 prediction
Utku, Anıl; Can, Ümit; Kamal, Mustafa; Das, Narasingha; Cifuentes-Faura, Javier; Barut, Abdulkadir
Beijing, Shanghai, Singapore, and London are regions with high population density and industrial activities. In this sense, accurate prediction of the rate of particulate matter 2.5 (PM_2.5), one of the most important air pollutants, is very important for creating a healthy ecological system. This study proposes a hybrid method to predict PM_2.5 with high success. This method aims to optimize the Long Short-Term Memory (LSTM) deep learning model, which successfully solves time series problems with a Genetic Algorithm (GA). Here, the hyperparameters of the LSTM model, such as the number of layers, number of neurons, number of epochs, and kernel size, are optimized to achieve the highest prediction rate. Against this backdrop, the present study uses for the first time a hybrid GA-LSTM model to predict PM_2.5 concentrations in Beijing, Shanghai, Singapore, and London. The Beijing dataset consists of 13 attributes, the Shanghai dataset consists of 10 attributes, the London dataset consists of 5 attributes, and the Singapore dataset consists of 7 attributes. In this study, input variables such as PM_2.5, DEWP, TEMP, PRESS, WS, WD, PRE, Snowfall hours, Rain hours, and Season were used. To assess the effectiveness of this hybrid method, the developed GA-LSTM model was compared with k-Nearest Neighbors (kNN), Random Forest (RF), Support Vector Regression (SVR), Extreme Gradient Boosting (XGBoost), Convolutional Neural Networks (CNN), LSTM, and Gated Recurrent Units (GRU). Experimental results showed that GA-LSTM outperformed the compared models. In addition, one of the best results was obtained compared to other models in the literature.
AtıfScopus17OpenAlex18İncele - MakaleAçık Erişim2023Scopus SJRQ1Magneto-couple stress of tri-hybrid metallic oxide nanomaterials in porous media with nonlinear properties for thermal technology advancement
Salawu, S.O.; Obalalu, A.M.; Fatunmbi, E.O.; Disu, A.B.; Akkurt, Nevzat
The rising industrial demand for technological advancement in improving their working fluids and thermal augmentation has prompted studies on various non-Newtonian fluids and nanofluids. These play momentous role in many engineering devices and electronics development. Therefore, this study seeks to examine the thermal performance of ternary hybridized magneto-couple stress nanofluids in permeable media with nonlinear thermofluidic properties. The dispersion of suspended cobalt ferrite CoFe2O4, titanium dioxide TiO2 and magnesium oxide MgO nanoparticles occurs in H2O conventional solvent. With isothermal energy, the tri-hybrid nanofluid is controlled by stretchy velocity, magnetic field, gravity and Ohmic heating. An invariant transmutation of the partial derivative model is offered using similarity variables. The complete solutions to the model are obtained via Chebyshev technique coupled with integrated collocation method. From the graphically presented results, it is revealed that strong heat transfer is provided by ternary CoFe2O4+Ti02+MgO nanofluids compared to CoFe2O4+Ti02 and CoFe2O4 nanofluids. Also, the nanofluid concentration volume fraction enhanced thermal distribution and performance in the system.
AtıfScopus26WoS26OpenAlex27İncele - MakaleYalnız künye2023Scopus SJRQ1Energy, exergy and cost analysis of different hemispherical solar distillers: A comparative study
Hadi Attia, Mohammed El; Hussein, Ahmed Kadhim; Radhakrishnan, Ganesh; Vaithilingam, Sivakumar; Younis, Obai; Akkurt, Nevzat
The experimental study of the results of reflective aluminum foils, metal sheets, and phosphate granules on the productivity and efficiency of hemispherical solar stills was given throughout this work under the solar conditions of the city of El-Oued (Algeria). Solar stills were designed, manufactured, and tested in August 2020. A standard hemispherical solar still was made of wood and coated with black silicon. It was considered a traditional solar still. Although it was compared to traditional solar stills, it was improved by covering its side walls with reflective aluminum foil, zinc metal sheets, and copper sheets. It had been found that the productivity of the modified still was 8.67%, 29.08%, and 42.35%, respectively, on top of that of the traditional solar still. This could be due to the activity of the foils and metals, which reflect more radiation and store energy, increasing the temperature of the salt water in the basin. In the second experiment, three modified solar stills in line with aluminum foil and phosphate granules (30 g/L), zinc metal sheet and phosphate granules, and copper metal sheet and phosphate granules were collectively used. It had been found that the productivity of the modified solar still with aluminum foil and phosphate granules (the improvement rate is 30.61%) was on the far side of that with zinc metal sheets and phosphate granules (the improvement rate is 49.961%) and copper metal sheets and phosphate granules (the improvement rate is 62.24%).
AtıfScopus37OpenAlex34İncele - MakaleAçık Erişim2023Scopus SJRQ1Analysis of unsteady thermo-solutal MoS2-EO Brinkman electro-conductive reactive nanofluid transport in a hybrid rotating Hall MHD generator
Shamshuddin, M.D.; Bég, O. Anwar; Akkurt, Nevzat; Leonard, Henry J.; Bég, Tasveer A.
MHD rotating generators offer a plausible renewable energy mechanism. New designs are emerging in which nanotechnology is contributing. Such systems are increasingly deploying more complex functional fluid materials such as base fluids containing magnetic nanoparticles which constitute electromagnetic nanofluids and can be tuned to enhance efficiencies. Motivated by these developments, a mathematical model is presented for the combined effects of Hall current, heat source, chemical reaction and radiative flux on the unsteady rotating thermo-solutal magnetohydrodynamic transport of a Molybdenum disulphide (MoS 2)-EO oil electroconductive Brinkman nanofluid to study the boundary layer characteristics in the vicinity of the side wall of an MHD generator system. The governing dimensional conservation equations are scaled using appropriate transformations into a system of dimensionless coupled partial differential equations. Under appropriate initial and boundary conditions, solutions are derived using the Laplace Transform Method (LTM) and complex variables. The physical impacts of the magnetic, nanoscale, thermal and species control parameters on primary and secondary velocity, temperature and concentration are visualized graphically. The judicious doping of the base fluid with MoS 2 nanoparticles is shown to achieve superior thermal performance for MHD rotating energy generators.
AtıfScopus38OpenAlex24İncele - MakaleAçık Erişim2023Scopus SJRQ2Binary PCL–waste photopolymer blends for biodegradable food packaging applications
Gürler, Nedim; Pekdemir, Mustafa Ersin; Torğut, Gülben; Kök, Mediha
The aim of this study is to prepare waste photopolymer (WPP) / poly ɛ-caprolactone (PCL) blends that can be used in food packaging with different ratios (5%, 10%, 20% and 30%) WPP. The structural properties of the blend films were characterized by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Opacity, surface color, water vapor permeability and shape memory properties of these films were examined. Pure PCL film exhibited more thermal stability compared to PCL/WPP blend films. Therewithal, the glass transition temperature of the pure PCL film showed a shift. Water vapor permeability improved with the addition of WPP. L*, a* and transmittance values reduced with increasing WPP, but b* value increased. It was thought that these polymer blends would enable to be used as packaging material in terms of compatibility and waste evaluation.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ2Stress analysis of the contact problem in a functionally graded layer loaded with a distributed load and two rigid circular punches resting on an elastic two quarter planes
Kaya, Fatih; Polat, Alper
In this study, the solution of the contact problem in a functionally graded (FG) layer resting on elastic two quarter planes was done using the finite element method (FEM). The contact problem consists of two rigid circular punches loaded FG and two elastic quarter planes. P and Q loads are transmitted to the FG layer by two rigid circular punches. All surfaces in the problem were considered as frictionless and the weight effect is also taken into account. The two-dimensional model of the contact problem was created with the ANSYS package program based on FEM and the stress analyzes were performed. All operations of quarter planes and circular punches are done with standard ANSYS menus. However, defining the material properties of the FG layer and dividing into meshes in finite elements cannot be done with standard menus. For this reason, a special macro was added to the program in order to define the material properties of the FG layer and to perform the mesh division, and the necessary parameters were applied to the layer by this macro. In the study, the effects of external load, stiffness parameter (βh), density parameter (γh) and contact stresses of distributed load change, normal stresses, and stresses along the depth were investigated.
AtıfScopus6WoS6OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ1A novel radial basis Bayesian regularization deep neural network for the Maxwell nanofluid applied on the Buongiorno model
Sabir, Zulqurnain; Akkurt, Nevzat; Ben Said, Salem
The aim of this work is to provide the numerical solutions of the fluid model by using the stochastic computing paradigms. The linear/exponential stretching sheets on magneto-rotating flow based on the Maxwell nanofluid have been provided using the Buongiorno model with the impacts of uneven heat source/sink, varying thermal conductivity and reactive species. The solutions of this transformed ordinary differential exponential stretching sheet model have been presented using a novel ‘radial basis’ (RB) activation function together with the Bayesian regularization deep neural network (BRDNN), i.e., RB-BRDNN. The deep neural network is presented into two hidden layers, while thirteen and twenty-five numbers of neurons have been used in the first and second layer. A reference dataset is proposed using the Runge-Kutta scheme for the model. The correctness of the stochastic RB-BRDNN procedure is examined through the comparison of proposed and database results, whereas minimal absolute error values provide the accuracy of the scheme. The reliability and competence of the computing RB-BRDNN solver is authenticated using the state transitions, correlation, regression, and error histograms.
AtıfScopus33WoS30OpenAlex36İncele - MakaleYalnız künye2023Scopus SJRQ1The structure, optical basicity, ligand field strength and shielding parameters of alkali/alkaline borate glasses doped with V2O5
Sayyed, M.I.; Abdel-Ghany, A.M.; Askin, A.; Sedqy, E.M.; Sadeq, M.S.
In this work, we study the structural, optical and radiation shielding properties of Na2O–CaO-borate glass doped with different amounts of V2O5. A glass system with the composition (10.5CaO+ 16.5Na2O+ (73-x)B2O3+ xV2O5; where x = 0, 2.5, 5 and 10.5 mol%) was produced following the melt quenching technique. The molar volume and density of glasses both increase with the increase in V2O5:B2O3 ratios. Moreover, the average ligand field strength reduced from 2.32 to 2.15 × 1016 cm2 with the increase in V2O5:B2O3 ratios, which correlates with the increased values of molar volume and interatomic separations. Furthermore, the optical basicity of the glass samples increased from 0.601 to 0.666 with increasing V2O5:B2O3 ratios. The optical absorption spectra are studied for further investigation of the optical features. To extract the absorption edge and the absorption bands, a deconvolution process was applied to the absorption spectra. The obtained bands from this deconvolution process confirmed the presence of vanadium in its oxidation states V3+, V4+ and V5+. Furthermore, more additions of V2O5 produced an obvious reduction in Eg values from 3.69 to 3.08 eV along with a redshift in the fundamental absorption edges. These results were attributed to the further creation of nonbridging oxygens within the glass matrix. Furthermore, the addition of V2O5 rather than B2O3 enhances the radiation shielding parameters. Accordingly, the CaNaBV10.5 glass sample is the best attenuator among the fabricated CaO–Na2O–B2O3–V2O5 glasses due to the highest mass attenuation coefficient and lowest half-value layer. Moreover, the half-value layer values of the present glasses were compared to some common materials in the radiation shielding field. From this comparison, we concluded that all glass samples are better than commercial glass windows and ordinary concrete.
AtıfScopus19OpenAlex21İncele - MakaleYalnız künye2023Scopus SJRQ2Ag seed layer effects on SnO2 thin films for triboelectric devices
Yüzüak, E.; Yüzüak, G. Durak
Materials with triboelectric properties are critical to boosting the efficiency of triboelectric nanogenerators (TENG) by gathering power from waste force and mechanical movement. In this study, we explored tin-oxide (SnO2) thin films with silver (Ag) seed layer properties for friction surfaces at TENGs. Investigation of the triboelectric behavior of semi-conductor/polymer coupling structured TENGs formed by thin films with and without Ag seed layer after heat treatment was explored by X-ray diffraction (XRD), electron microscopy (SEM), atomic force microscopy (AFM), and semi-logarithmic current-voltage measurements. Similar structural characterization studies were carried out in indium tin oxide coated polyethylene terephthalate film (PET/ITO) for the polymer friction layer. Semiconductor/polymer coupling structured TENG efficiency was evaluated in contact-separation mode and the output voltage-current was enhanced to 80 V, 4 μA, and 210 μW of output power calculated by depositing a SnO2 thin film on an Ag seed layer, respectively. Our findings offer a different perspective for synthesizing the semi-conductor/polymer coupling structured TENGs for promising applications in a range of application technologies.
AtıfScopus2WoS2OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ1Investigation of surface morphology, optical properties and the gamma radiation effect on selenium coated glass substrate containing rare earth oxide
Taşgin, Yahya; Kanca, Muhammed Sait; Kök, Mediha
In this study, in order to add different properties and functions to inorganic amorphous glasses, the applicability and effects of the thin film coating produced by thermal evaporation method were examined by metallographically imaging the effects of 3%–5% CeO2 and Tm2O3 rare earth elements (REE) oxide added to selenium to change the morphology of the glass surface. As a result of the study, it has been proved that CeO 2 and Tm2O3 added to selenium can be coated by thermal evaporation method with AFM images taken from the glass surface and metallographic analyses (SEM, EDX, Mapping). The lowest roughness value was observed in 95Se–5CeO2 coating glass substrate. In all coatings, selenium, which is the main sample, was found to be active, and XRD measurements showed that the thin films were formed by agglomeration on the (101) plane. According to UV-VIS measurements, the lowest optical band energy range was observed in the 95Se–5CeO2 coating.
AtıfScopus11WoS10OpenAlex12İncele - MakaleAçık Erişim2023Scopus SJRQ1Modeling and numerical simulation of non-Newtonian arterial blood flow for mild to severe stenosis
Nadeem, Sohail; Ali, Shahbaz; Akkurt, Nevzat; Ben Hamida, Mohamed Bechir; Almutairi, Shahah; Ali Ghazwani, Hassan; Eldin, Sayed M; Khan, Zareen A.; Al-Shafay, A.S.
The fundamental cause of coronary heart disease is thought to be atherosclerosis. Blood flow in arteries under plaque formation is widely studied using both experimental and theoretical methods in literature. This paper presents a comprehensive study on the mathematical modelling and numerical simulation of non-Newtonian blood flow in an idealized stenosed artery. Non-Newtonian behavior of blood flow is assumed by Casson and Quemada fluid models. An analysis is performed for four forms of stenosis, 50%, 60%, 70%, and 80%, which are defined by a narrowing of the artery's diameter. The mathematical model for non-Newtonian fluid transport is presented in the form of highly nonlinear coupled partial differential equations. A finite-volume approach is used to solve the system of equations numerically. The solutions are obtained using a hybrid mesh with hexahedron and tetrahedron control volumes. Numerical solutions are validated first with experimental results from the literature for a Newtonian fluid, and then the results are extended to non-Newtonian fluid models. It can be observed that the non-Newtonian nature of the fluid model influences flow dynamics and is a significant aspect to consider for arteries with small diameter. The velocity and pressure drop rise as the degree of stenosis develops. Wall shear is substantially larger in stenotic passages and severity of stenosis is directly related with this increasing behavior.
AtıfScopus32OpenAlex33İncele - MakaleYalnız künye2022Scopus SJRQ1Dynamic response model and equivalent solution method of large-diameter buried energy transportation pipeline under moving load
Xu, Qian; Yang, Gang; Li, Zhuorui; Zou, Zhenwei; Zheng, Qiang; Zhong, Liqiong; Chen, Xingli; Akkurt, Nevzat; Du, Yanping; Xiong, Yaxuan
Long-distance energy pipeline pass under roads, subjecting them to repeated stress and posing pipeline safety problems. To simulate the effects of vehicles driving over energy transmission pipeline, this paper examines large-caliber buried pipelines in the suburbs. In this study, a mechanical action model of vehicle-soil-pipeline (VSP) interactions to transform the process of a vehicle driving into the dynamic process of a load changing with time in the specified area was created. The VSP model was used to analyze the influence of moving load and position on the structural characteristics of the pipeline section. An equivalent solution method with high precision and high calculation efficiency was proposed. The results showed that as the loading position approaches the pipeline or the load increases, the stress value at the top of the pipeline gradually exceeded the stress value at the bottom of the pipeline and became the area with the maximum stress value. The minimum stress location also changed from the lower half near the pipeline bottom (Point D-135°) to the upper half near the pipeline top (Point B-45°or Point H-315°). Using the polynomial fitting method, the stress values of the maximum points were equivalently converted. Under the premise of considering pipeline safety, the most suitable functional relationship for the moving load equivalent model was obtained.
AtıfScopus16OpenAlex13İncele - MakaleAçık Erişim2022Scopus SJRQ1A method for generation of substitution box based on random selection
Artuğer, Fırat; Özkaynak, Fatih
Two basic requirements must be met to encrypt data. These requirements are confusion and diffusion properties. In particular, block cipher algorithms are based on a cryptographic component known as substitution-box to provide the need for confusion. Therefore, attack scenarios generally focus on this cryptographic component. There are alternative design approaches for substitution-box design. It is known that each design approach has several advantages and disadvantages. In this study, an alternative method is proposed to address the problems of the substitution-box design approach based on random selection. The success of the proposed method has been tested in three different scenarios. Analysis results for these three scenarios showed that generated substitution-box provides performance increase for nonlinearity criterion from s-box design criteria. Successful results achieved; It points out that improvement cryptographic components can be used in a variety of practical applications such as block ciphers, masks to prevent side-channel attacks, random number generators, and image encryption algorithms.
AtıfScopus29WoS25OpenAlex35İncele - MakaleYalnız künye2022Scopus SJRQ2Thermal analysis of a radiative nanofluid over a stretching/shrinking cylinder with viscous dissipation
Alqahtani, Aisha M.; Riaz Khan, M.; Akkurt, Nevzat; Puneeth, V.; Alhowaity, Awatif; Hamam, Haneen
This study explores the impact of thermal radiation and viscous dissipation on the stagnation point flow of a copper–water nanofluid across a convective stretching/shrinking cylinder. The copper suspension in the base fluid water enables the fluid to conduct more heat by increasing its thermal conductivity. The mathematical model that governs the flow of Cu-H2O nanofluid is formulated by the system of partial differential equations (PDEs) which are then subjected to transformation by introducing suitable similarity variables so the system is transformed to the Ordinary Differential Equations (ODEs). These equations have been solved numerically via the bvp4c package in MATLAB. The outcomes have been signified graphically in the form of heat transfer rate, temperature, skin friction and velocity which are dependent on the concerning flow parameters. For each of these result, dual solutions have been produced which are conditional on the shrinking of cylinder. These results declare that the skin friction increases for the shrinking cylinder and decreases for the stretching cylinder whereas an opposite trend is seen for the rate of heat transfer. Similarly, heat transfer is found to be decreasing for the increase in both Biot and Eckert number. Meanwhile, the existence of greater values of curvature parameter causes to enhance both first and second solution of velocity as well as the temperature is augmenting with the increase in Eckert number and volume fraction of nano particles.
AtıfScopus38OpenAlex39İncele - MakaleAçık Erişim2022Scopus SJRQ1A multicriteria approach to integrating occupational safety & health performance and industry systems productivity in the context of aging workforce: A case study
Ortiz-Barrios, Miguel; Silvera-Natera, Esnela; Petrillo, Antonella; Gul, Muhammet; Yucesan, Melih
Aging represents one of the greatest challenges that mankind will have to face in the 21st century. In this regard, there is a need to deepen the technical and organizational aspects for rebalancing the job/employee relationship. Nevertheless, there are no robust approaches assisting decision-makers in the effective management of Occupational Safety & Health Performance (OSHP) and Industry Systems Productivity (ISP) convergence with a focus on Aging Workforce (AW). There is no single and unique solution. Therefore, in a win-to-win logic that favors the characteristic of the reference scenario, the aim of this paper is to propose a multicriteria approach to integrate OSHP and ISP in the context of AW. More specifically, Intuitionistic Fuzzy Analytic Hieararchy Process (IF-AHP) was used to elicit the criteria and sub-criteria under uncertainty considering degree of belongingness and non-belongingness. Decision Making Trial and Evaluation Laboratory (DEMATEL) was applied to evaluate the presence and strength of the interrelations and feedback among OSHP and ISP criteria and sub-criteria. Finally, Combined Compromise Solution (CoCoSo) was implemented to calculate a Working Suitability Index (WSI) per aging. Based on this index, interventions on each worker are proposed to underpin redesign of the company while to provide a flexible management propelling high performance in terms of OSHP and ISP. A real case study in Colombia is presented. The results revealed that Efficiency and Quality with 0.162 were found to be the most important factors in evaluating the performance of aging electrical engineers while Psychosocial risk and Occupational Safety were concluded to be the main drivers for a joint OSHP-ISP aging workforce management. The model can be an useful tool for policy and business decision-makers from the electrical sector and can be replicated with slight changes in other industries.
AtıfScopus17WoS11OpenAlex23İncele - MakaleYalnız künye2022Scopus SJRQ1Morpho-structural and optoelectronic properties of diamond like carbon–germanium (DLC-Ge) composite thin films produced by magnetron sputtering
Aslan, Naim; Kurt, Mustafa Şükrü; Mehmet Koç, Mümin
Diamond-like carbon films have found various areas of application due to their particularly durable characteristics. To enhance the electrical and optoelectronic characteristics of the material, diamond-like carbon was co-deposited with Ge on p-type Si wafer using the DC magnetron sputtering technique, from which diamond-like carbon-germanium nanocomposites were obtained. The structural properties of the nanocomposites were assessed using electron microscopy techniques. The chemical structure of the nanocomposite films was confirmed using energy dispersive spectroscopy and Raman spectroscopy. The electrical properties of the nanocomposite films were investigated via various electrical parameters as determined through current-voltage, capacitance–voltage, and conductance–voltage graphs. Photoresponsive and photosensitivity properties were also assessed using a solar simulator at various illumination intensities. It was concluded that nanocomposite thin films were responsive to light, where photosensitivity and photoresponsivity increased with increasing illumination intensity. The electrical characteristics of the nanocomposite films were associated with the frequency of the AC voltage applied.
AtıfScopus27WoS23OpenAlex27İncele - MakaleYalnız künye2022Scopus SJRQ3Examining the perspectives of textile workers on organ donation and related factors
Yeşiltepe, Akgün; Bulbuloglu, Semra; Aslan, Sinan
Objective: In this study, we aimed to examine the perspectives of textile workers on organ donation and related factors. Method: The sample of this descriptive and cross-sectional study consisted of employees of a textile factory located in eastern Turkey (n = 166). The data were collected using the forms Personal Information and determining Knowledge, Awareness, and Willingness regarding Organ Donation and Transplantation. Data collection forms were prepared by researchers based on the literature and taking expert opinion. In the analysis of the study data, number-percentage, chi-square test and Cramér's phi correlation analysis were used. Results: The mean age of the participants was 21.10 ± 2.53, and the numbers of men and women were equal. It was determined that 63.3% of the participants needed education related to organ donation, and 57.8% were willing to donate their organs. There is a correlation the high levels of knowledge, awareness, and willingness regarding organ donation and transplantation with the participant's levels of thinking about donating their organs. Conclusion: Our results supported the view that high levels of knowledge and awareness increased willingness about organ donation. In increasing the number of organ donors, high levels of knowledge and awareness are highly important, all parts of society should be provided with education on this issue, and it should be considered that workers of all sectors, especially textile workers, constitute a significant proportion of most societies in terms of numbers.
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