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Koleksiyondaki öğeler
- MakaleAçık Erişim2024Scopus SJRQ2External oxide layers formed by the oxidation procedure in FeMnSi and FeMnSiCr shape memory alloys and their effects
Tatar, Cengiz; Kök, Mediha; Kanca, M Sait; Tatar, Beyhan
Shape memory alloys are exposed to high temperatures to improve their properties and functionality. Through this process, oxidation inevitably occurs due to the presence of oxygen in the environment, which interacts with the alloying elements. Oxidation adversely affects the hardness of alloys, leading to a decline in their overall quality. In this study, the oxidation behavior parameters of FeMnSi and FeMnSi-Cr alloys and the oxide layers formed during this process were investigated in Fe-based alloys with high usage potential. Both non-isothermal and isothermal oxidation processes were applied to alloys and the oxidation parameters were determined. Subsequently, the changes in the crystal structure, microstructure, and magnetic properties of the alloys subjected to isothermal oxidation at 400-500-600-700-800 °C were investigated. It was found that the oxidation behavior of both alloys intensified with rising oxidation temperatures, as evidenced by crystal structure and microstructural analyses, which indicated deeper penetration into the alloys at elevated temperatures. Furthermore, an increase in magnetization values was noted alongside the oxidation process. A comparison of the oxidation characteristics between FeMnSi and FeMnSi-Cr alloys revealed that the oxidation parameters for the chromium doped FeMnSi alloy were comparatively lower.
AtıfScopus2OpenAlex2
İncele - MakaleYalnız künye2024Scopus SJRQ2Effect of repair patch nature on J-integral reduction in notched plates
Houari, Amin; Kouider, Madani; Polat, Alper; Amroune, Salah; Mohamad, Barhm Abdullah; Chellil, Ahmed; Campilho, Raul
Purpose: The purpose of this research is to evaluate the effectiveness of different repair patch materials in reducing the stresses at the crack tip of a 2024-T3 aluminum plate. This involves a numerical analysis using the finite element method (FEM) to estimate the reduction in the J-integral value, with the goal of identifying how various parameters related to the patch materials, adhesive properties and loading conditions influence the structural integrity of the repaired plate. Design/methodology/approach: The methodology of this research involves conducting a numerical analysis using the FEM to estimate the reduction in the J-integral value at the crack tip of a 2024-T3 aluminum plate. Three types of patches – metal, composite and functionally graded material (FGM) – were examined under tensile loading conditions, and Adekit-A140 adhesive was used to bond these repair patches to the aluminum plate. Findings: The analysis considered various parameters, including crack length, the nature of fibers in the composite material, the gradation exponent for FGM patches and the nature of the face in contact with the adhesive for the FGM patch. Additionally, stress analysis was conducted, examining the J-integral values for the plate, shear stress in the adhesive layer and peel stress in the composite patch. The findings highlight that modifying the nature of the repair patch used can significantly enhance the structural integrity of the repaired plate. Originality/value: The study analyzed J-integral values, shear stress in the adhesive and peel stress in the composite patch. Various parameters, including crack length, fiber type, gradation exponent and adhesive contact face nature, were considered. Results demonstrate that the J-integral value can be significantly reduced by altering the repair patch type, highlighting the effectiveness of customized patch materials in enhancing structural integrity.
AtıfScopus4OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ4Experimental Study on Engineering Properties of Recycled Olivine Aggregate Filled CF Reinforced Electrically Conductive Mortars
Dehghanpour, Heydar; Doğan, Fatih; Subaşı, Serkan; Maraşlı, Muhammed
Electrically conductive concretes produced for different purposes were introduced years ago and since then, intensive scientific research has been going on. Studies in the literature have generally been carried out on conventional concretes with electrical conductivity for floor applications. The current study investigates carbon fiber reinforced mortars filled with fine olivine aggregate. Fine aggregate filled mortars are generally produced for building facade applications. Within the scope of the study, the mechanical, electrical, dynamic and microstructural properties of cementitious mortars containing 0.5%, 0.75% and 1.0% carbon fiber and 100% recycled olivine aggregate were investigated. The purpose of performing dynamic resonance tests was to investigate the effect of carbon fiber on damping ratio. 28-Day compressive, flexural, dynamic resonance, ultrasonic pulse velocity (UPV), Leeb hardness and dry density tests of conductive mortar samples obtained from four different mixtures were performed. In addition, 2, 14, 28, 90 and 180 days electrical conductivity tests were carried out to determine their resistivity in different time intervals. The purpose of performing dynamic resonance tests was to investigate the effect of carbon fiber on damping ratio. While a significant positive effect of CF on electrical conductivity and damping ratio was observed, a negligible decrease in mechanical results was observed. Calcium silicate hydrate (C-S-H) structure formed by hydration using olivine filler in the cement mixture confirmed the binding formations.
AtıfOpenAlex1TR Dizin1
İncele - MakaleAçık Erişim2024Scopus SJRQ3ENHANCING MILLING PERFORMANCE OF 6061 ALUMINUM ALLOY WITH NANOCUTTING FLUID AND MQL
Tosun, Nihat; Rasul, Sleman Yahya; Mahmat, Aybars; Tosun, Gul
During the machining of aluminum alloys, the adhesion of chips to the tool affects the performance characteristics. Today, different cooling systems are used to eliminate these negativities. In this study, the effects of end milling using HSS and carbide cutting tools of 6061-T6 aluminum alloy on surface roughness, chip thickness ratio and tool wear were examined using different cooling techniques (dry, minimum quantity lubrication (MQL) and nanocutting fluid). Different cutting speeds (180, 200, 220 m/min) and different feed rates (0.05, 0.06, 0.07 mm/rev) were used in the experiments. According to experimental findings, tool wear and surface roughness decreased at low cutting speed and feed rate by using nanocutting fluid with carbide cutting tools. It has been observed that the chip thickness ratio increases with high cutting speeds using nanocutting fluid and decreases with dry machining and high feed rates. The best milling performance of the aluminum alloy was achieved in experiments using carbide cutting tools and nanocutting fluid.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ4Investigation of the Spectrum of Nonself-Adjoint Discontinuous Sturm-Liouville Operator
Akçay, Özge; Koşar, Nida Palamut
In this paper, we study nonself-adjoint Sturm-Liouville operator containing both the discontinuous coefficient and discontinuity conditions at some point on the positive half-line. The eigenvalues and the spectral singularities of this problem are examined and it is proved that this problem has a finite number of spectral singularities and eigenvalues with finite multiplicities under two different additional conditions. Furthermore, the principal functions corresponding to the eigenvalues and the spectral singularities of this operator are determined.
- MakaleAçık Erişim2024Scopus SJRQ1Influence of Plastic Deformation and Hydroxyapatite Coating on Structure, Mechanical, Corrosion, Antibacterial and Cell Viability Properties of Zinc Based Biodegradable Alloys
Aksakal, B.; Isın, Ege; Aslan, N.; Cihangir, S.; Sezek, S.; Yilmazer, Yasemin
Zinc (Zn)-based biodegradable alloys have been at the forefront of absorbable biomaterial research in recent years due to their high biocompatibility and corrosion rates. The arc melting process was used to produce the Zn–1Cu–1Ag biodegradable alloy. The influence of different plastic deformation rates on the microstructure of the material was examined after the cold rolling at deformation rates of 47% and 61%. The undeformed and deformed alloys have been hydroxyapatite-coated using the electrophoretic deposition process to improve its surface, corrosion, and bioactivity properties. Optical, XRD, SEM, and EDS examinations were used to analyze the samples’ uncoated, coated, and rolled-unrolled forms. The nucleation of the (Ag, Cu)Zn4 secondary phase was formed during the rolling process. Hardness and compression tests were used to determine the mechanical properties of cast and rolled alloys, and in vitro corrosion tests were carried out in simulated body fluid. Antimicrobial and cell viability tests are executed to demonstrate the biocompatibility of the deformed and HA-coated Zn–1Cu–1Ag alloy. The mechanical properties were improved after the rolling process, with the highest results found in 47% of the rolled samples exhibiting a compressive strength of 412.65 ± 0.5 MPa and 61% of the rolled samples exhibiting a hardness value of 88.1 ± 0.5 HV. The samples that were rolled (61%) and coated with hydroxyapatite (HA) exhibited the highest level of corrosion resistance. The antimicrobial tests revealed that the rolled and HA coated Zn1Cu1Ag groups exhibited greater inhibition rates (47 and 61%) compared to the other groups when tested against E. coli. The HA-coated groups exhibited good cell viability ratios, with the maximum viability seen in the rolled and HA-coated group at 47%.
AtıfScopus4WoS5OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ1Case study of thermal and solutal aspects on non-Newtonian Prandtl hybrid nanofluid flowing via stretchable sheet: Multiple slip solution
Shamshuddin, MD.; Raizah, Zehba; Akkurt, Nevzat; Patil, Vishwambhar S.; Eldin, Sayed M.
The effect of multiple slip boundary conditions is one more important physical parameter on the flow investigation and have been studied in this analysis. Further, the effect of Ohmic heating and varying chemical reaction on non-Newtonian Prandtl hybrid nanofluid with water based nanofluids to an extending of leading edge was also investigated to this current analysis. An inclined magnetic field is introduced to fluid flow to regulate the fluid stream. Hybrid nanomaterial is synthesized by the dispersion of Cu and Cofe2O4 nanoparticles in Prandtl fluid. All chemical science specifications of nanofluid are measured as constant. Due to the nanofluid particles motion, the fluid concentration is inspected underneath chemical implications. A mathematical model is developed by assuming the flow as incompressible and purely cartesian coordinate system and appropriate non-dimensional variables are introduced for problem simplifications and dimensional analysis. The scheme for semi analytical study named Homotopy Analysis Method (HAM) is implied to get solutions to the equations. The procedure is then displayed pictorially where fluid velocity, temperature and concertation against various pertinent parameters are examined. It was found that, the Concentration field profiles have been shown to deteriorate because molecule diffusivity reduces as the chemical reaction parameter rises in both cases. In order to maintain thermal balance management in tiny heat density equipment and gadgets, current research may also be helpful in enhancing the thermal efficiency of heat exchangers.
AtıfScopus41WoS38OpenAlex44İncele - MakaleYalnız künye2023Scopus SJRQ2Computer-aided Optimization of Geopolymer Mortars
Gülmez, Nihan; Koçkal, Niyazi Uğur
The optimum mix design of geopolymers involves the purpose of determining which mixture will have high engineering properties without compromising the importance of each variable. This experimental study aimed to investigate the effects of some critical geopolymer mixture parameters on engineering properties by using historical data design in response surface methodology (RSM). Statistical models were developed between factors (binder and aggregate content, curing conditions and aggregate type) and their response surfaces (oven dry (OD) bulk density, water absorption, compressive strength and flexural strength). The final mathematical models for the response surfaces were constructed in terms of coded factors defined as dimensionless. In addition, a multipurpose optimization technique was used to achieve the desired design with the desired maximum strength.
- MakaleAçık Erişim2024Scopus SJRQ1Enhanced photocatalytic abilities of innovative NbTaZrMoW high-entropy alloys (HEAs): a comparative analysis with its high entropy oxide (HEO) counterpart
Zakir, O.; Guler, O.; Idouhli, R.; Nayad, A.; Khadiri, M.E.; Guler, S.H.; Abouelfida, A.; Dikici, B.
The photocatalytic performance of high entropy alloy (HEA) and its oxide form (high entropy oxide, HEO) have been evaluated in this study. The HEA, composed of Nb, Ta, Zr, Mo, and W powders, was synthesized through a mechanical alloying process for 120 h. This process was carried out under a high-purity Ar atmosphere to prevent oxidation. Subsequently, the HEA was converted into HEO via a mechano-thermal oxidation method 900 °C for 12 h. The photocatalytic activity of both oxidized and non-oxidized samples was systematically evaluated by degradation of methyl blue (MB) under UV irradiation. Electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to investigate the structural and chemical features of the alloys. Furthermore, BET surface area analysis and Zeta potential measurements were conducted to understand the alloys’ surface properties and stability in aqueous solutions. The results showed that the HEA has a remarkable photodegradation performance of around 58.77% which is two times higher than that observed with the HEO. Graphical abstract: (Figure presented.)
AtıfScopus31WoS30OpenAlex28İncele - MakaleYalnız künye2025Scopus SJRQ1Airbnbfication and gentrification from the perspective of rent gap theory: the case of Beyoğlu, Istanbul
Çobangil, Orçun; Ateş, Erdem
This paper examines how Airbnbification affects the rental market in Istanbul's historic Beyoğlu district using rent gap theory. Given Turkey's recent soaring inflation rates, special emphasis is placed on inflation, aligning with Neil Smith's focus on its impact on rent gap formation. Beyoğlu's history and urban development in the context of neoliberalisation of Istanbul are considered, highlighting why it alone hosts 15.36% of Turkey's Airbnb listings. The analysis proceeds in four stages: first, by comparing long-term rental incomes with Airbnb revenues; second, by assessing inflation and rental growth rates; third, using Pearson correlation to analyse inflation and Airbnbification; and finally, employing the Vector Error Correction Model (VECM) to explore both short- and long-term relationships and Granger causality. These findings suggest Airbnb listings, rising rents, and inflation contribute to the ongoing rent gap, positioning Airbnbification as the latest phase of Beyoğlu's gentrification.
AtıfScopus4WoS3OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2ZrN and ta-C coatings on titanium for biomedical applications: Improved adhesion, corrosion, antibacterial activity, and cytotoxicity properties
Aslan, Naim; Aksakal, Bünyamin; Cihangir, Salih; Cetin, Fadime; Yilmazer, Yasemin
Commercially pure titanium (CP-Ti) is extensively used in biomedical applications. However, numerous qualities, including mechanical strength, corrosion resistance, and wear resistance, must be established for long-term performance as an implant material. This study investigates the enhancement of surface properties of CP-Ti through physical vapor deposition (PVD) with ZrN and ta-C (tetrahedral amorphous carbon). Among the coatings, ZrN revealed best overall results, such as adhesion, corrosion, microhardness, and wettability, excluding cell viability when compared to ta-C. E. coli and S. aureus were employed for antibacterial activity and MTS cell viability experiments. Compared to α-titanium, hardness tests revealed 91% increase in ZrN coating, and %22 increase in ta-C coating. Super-hydrophobicity and excellent antibacterial activity were found for ZrN coatings in comparison to ta-C. These findings emphasize the potential of ZrN and ta-C coatings to improve the surface properties of titanium, encouraging it to be used in biomedical devices. Graphical abstract: [Figure not available: see fulltext.].
AtıfScopus16WoS16OpenAlex19İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigation of fundamental electrical and optoelectronic properties of an organic- and carbon-based MnPc/GC photodiode with high photosensitivity
Aktas, Sitki; Unal, Fatih; Kurt, Mustafa Sukru; Koç, Mümin Mehmet; Arslan, Tayfun; Aslan, Naim; Coşkun, Burhan
The aim of this work is to provide an alternative to optoelectronic devices that use carbon and organic materials. To achieve this, we coated a modified MnPc organic semiconductor compound onto a graphite-like carbon (GC) thin film using the thermal evaporation technique, and fabricated an organic-based, highly light-sensitive MnPc/GC hybrid heterojunction. The heterojunction had a transmittance of approximately 60% in the visible region, an absorption coefficient of ∼106 m−1, and an energy band gap of 2.6 eV. Subsequently, Ag contacts were grown on the surface of each layer, and the Ag/MnPc/GC/Ag photodiode was subjected to fundamental electrical analysis at various light intensities and a ±3 V applied potential. Analysis in a dark environment revealed that the photodiode had a rectification ratio of 2.59 × 103, a series resistance of 28 Ω, and a shunt resistance of 4.17 × 104 Ω, as calculated from Ohm’s law. The diode ideality factor and barrier height of the photodiode were determined from thermionic emission theory to be 5.60 and 0.71 eV, respectively, and it was observed that these decreased with increasing light intensity. The photodetector parameters of the MnPc/GC hybrid photodiode were determined under positive and negative applied potentials at various light intensities. The highest photocurrent, photoconductive responsivity, photosensitivity, and specific detectivity were determined to be 1.512 × 10−1 A, 11.52 A.W−1, 9.83 × 105, and 2.48 × 1012 Jones, respectively, which were significantly higher than those reported in literature for organic and inorganic-based photodiodes. Based on the findings, it was concluded that the Ag/MnPc/GC/Ag photodiode holds promise as an alternative for sensors, solar cells, photodetectors, and optoelectronic communications applications.
AtıfScopus10WoS9OpenAlex14İncele - MakaleAçık Erişim2024Scopus SJRQ2Physical and shielding properties of Er2O3 rare earth oxide compound content on PCL/PEG blend
Taşgin, Yahya; Pekdemir, Mustafa Ersin; Yilmaz, Mücahit; Kanca, Muhammed Sait; Kök, Mediha
Rare earth elements (RRE), due to their unique magnetic, electrical, and optical properties, are an important group of elements demanded in many application areas from machine technology to the health industry. In this study, new composites were obtained by mixing Erbium oxide (Er2O3), one of the rare earth element oxides, into PCL–PEG blend, which is also an important material group, in different ratios. The characteristic functional groups of the obtained polymer blend/Er2O3 nanocomposites were determined by the ATR-IR, and as the erbium oxide ratio increased, characteristic peaks of the polymers in the blend as well as characteristic signals of the Er–O–Er bond were found. When the thermal behavior of the obtained composites was examined, it was observed that the polymer blend exhibited miscible blend properties and the melting temperature of the polymer blend increased as the Er2O3 ratio increased. In addition, it was determined that the thermal stability of the composite increased significantly. X-ray measurements of composites at room temperature support other measurement results. It was determined that the presence of Er-RRE oxide increased the crystal structure feature in the polymer blend composite. Gamma radiation shielding capabilities of polymer materials containing different erbium ratios were investigated by calculating shielding parameters such as half value layer (HVL), radiation protection efficiency (RPE), and mean free path (MFP). Cs-137 and Co-60 radioactive sources were used as gamma sources. According to the obtained measurement results, Erbium oxide increased the absorption property of the polymer composite material. Graphical abstract: [Figure not available: see fulltext.].
AtıfScopus26WoS28OpenAlex29İncele - MakaleYalnız künye2023Scopus SJRQ2Energy-momentum localization in rainbow gravity
Korunur, Murat; Korunur, Sibel
Theoretical physicists generally prefer to modify the general theory of relativity rather than avoiding the successful approaches that have been offered to us. Hence, the rainbow formalism of gravity, which is one of the most studied quantum gravity candidates in literature, has recently gained importance in the field. In this study, the energy-momentum localization problem is discussed for the Taub universe within the framework of rainbow gravity. To achieve this goal, energy and momentum components are calculated by making use of diverse values of rainbow functions in the Einstein, Bergmann-Thomson, Landau-Lifshitz, and the Papapetrou prescriptions for the geometry under consideration. Except for the Landau-Lifshitz prescription, all prescriptions depend on the rainbow functions and the momentum components vanish. Graphical analysis is performed for all the energies obtained. Also, it is shown in limiting condition f1(x) → 1; f2(x) → 1 that the results are compatible with the ones obtained in the general relativity.
AtıfOpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ2Genotoxic effects of copper nanoparticles on Vicia pannonica Crantz. root meristem cells
Tasar, Neslihan
With the increasing use of metal nanoparticles, their access to the food chain has become the main concern for scientists. The present study sheds light on the copper nanoparticles (Cu NPs), which are widely used in many industries today. For this purpose, Vicia pannonica Crantz., a common fodder plant, was used and exposed to metal-based Cu NPs. To determine the genotoxic effects on root meristem cells, total of 3 different concentrations (50 ppm, 150 ppm, and 300 ppm) of Cu NPs and the control in deionized water solutions were prepared. The determination of the accumulation and elimination of Cu NPs in Vicia pannonica used in the study was carried out using with X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM element mapping, and energy dispersive X-ray diffraction (EDS) characteristic spectrum analysis. All doses of Cu NPs caused significant decreases in the Mitotic index of V. pannonica meristem cells compared to the control. Multiple analyzes carried out in the study showed that Cu NPs caused abnormalities in cell division such as C-metaphase, polar aberration, deconstructed anaphase, chromosome breakage, loss of genetic material, failure to assemble in the metaphase plate, deconstructed metaphase, asynchronous division remaining chromosome in metaphase, adhesion, deconstructed prophase, advanced chromosomes, and chromosome bridges in anaphase. Results support that Cu NPs have a genotoxic effect on V. pannonica.
AtıfScopus5WoS2OpenAlex6İncele - MakaleYalnız künye2023Scopus SJRQ1Ultrasound assisted adsorptive removal of Cd+2 ions from the water system using Bi2S3 nano/micro flowers
Kurnaz Yetim, N.; Aslan, N.; Özcan, C.; Koç, M.M.
Heavy metal ions threaten public health and marine life; thus, removal of heavy metals is essential for the environment. Bi2S3 nanostructures are active materials which used in various applications. In this work, we produced Bi2S3 nanoflowers using hydrothermal synthesis and assessed their Cd2+ ions removal capability. Structural properties of the Bi2S3 nanoflowers were assessed by various like scanning electron microscopy, X-ray diffraction. Chemical characteristics of the materials were confirmed using energy dispersive X-ray spectra. Different parameters affecting the Cd2+ ion recovery was worked some of which are adsorbent amount, Cd2+ ion concentration, pH, adsorbent time, eluent type and amount, etc. For cadmium, the optimum pH was determined 8.0 for 1 M HNO3 eluent. Optimum adsorbent amount was determined as 150 mg while optimum recovery duration was found as 30 min. Bi2S3 nanoparticles managed to achieve 99.3% Cd2+ recovery rate in 5 mL eluent volume, for optimum condition. The adsorption capacity of the Bi2S3 nanoflowers was found to be promising and therefore, it was illustrated that Bi2S3 nanoflowers are good candidates as sorbent for water remediation applications.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ2Strong s-box construction approach based on Josephus problem
Artuğer, Fırat
There are two basic requirements for symmetric encryption algorithms. The first of these is diffusion. The second and most important is confusion. In these algorithms, this requirement is usually met by s-box structures. Therefore, s-box structures must be strong. So, a cryptographically good s-box will make the encryption algorithm difficult to crack. However, obtaining a strong s-box is a rather difficult problem. In this study, Josephus circle logic is used to solve this problem. Initially, with a random s-box structure, the elements are replaced according to their Josephus positions, and the s-box is made stronger. In the proposed algorithm, according to the Josephus logic, the elements that kill each other are replaced and this process continues until one element remains. The last 30 surviving elements are replaced with all elements. In this way, three different s-boxes were obtained. In two of them, the nonlinearity value was 110.5, and in one of them, the nonlinearity value was 110.75. Fixed points in the proposed s-box structures were identified and eliminated. In addition, it has been proven because of the analysis that the obtained s-box structures also meet other cryptographic requirements. In addition to leaving behind most studies in the literature, the proposed method will also provide strong s-box structures for encryption algorithms to be built in the future.
AtıfScopus15OpenAlex12İncele - MakaleYalnız künye2024Scopus SJRQ1Effect of boron on microstructure, thermal, and mechanical properties of Ni–B matrix diamond cutting tools
Islak, Serkan; Çelik, Ertuğrul; Houssain, Hasaneen; Danacı, Hacer Cemre
This study examines the impact of adding boron on the microstructural, thermal, and mechanical properties of Ni–B alloy matrix diamond cutting segments, which are created using the hot pressing process. Microstructure was investigated using SEM-EDS and XRD analysis. The high-temperature oxidation behavior of the samples was determined by thermogravimetric analysis. The hardness was quantified employing Vickers hardness testing, as well as, sample densities were derived based on Archimedes' principle. The wear resistance was evaluated using the reciprocating wear test method. A three-point bending test was used to examine how the diamond grains were retained inside the Ni–B matrix. The XRD investigations identified the formation of Ni, Ni3B, and Ni2B phases. The thermogravimetric analysis results showed that Ni–B alloys were exposed to oxidation at elevated temperatures as the B content increased, However, a hardness improvement was observed as the B content increased due to the formation of borides. Furthermore, the tribological investigation reveals that adding the B as reinforcement has a positive effect at a specific amount, where the optimal wear resistance and minimal friction coefficient were evident at 6% B contained sample.
AtıfScopus10WoS10OpenAlex10İncele - MakaleAçık Erişim2025Scopus SJRQ1Enhanced radiation shielding via incorporating europium oxide in 316L stainless steel: Synthesis, physical, microstructural, shielding, and mechanical properties
Tekin, H.O.; Yayla, Nihal; Albayrak, M.Gökhan; Güler, Ömer; Baykal, Duygu Sen; Alkarrani, Hessa; ALMisned, Ghada
316L stainless steel is widely utilized in various industries due to its excellent corrosion resistance, mechanical strength, and biocompatibility, making it a preferred material for applications in nuclear filed. However, enhancing its radiation shielding and mechanical properties through reinforcement strategies, such as the addition of high-Z materials like Europium(III) oxide, is crucial for extending its functionality in high-radiation environments, where improved performance is essential for safety and durability. In this study, 316L stainless steel composites reinforced with varying amounts of Eu2O3 (1%, 5%, 10%, and 20%) were synthesized and investigated for their structural, mechanical, and radiation shielding properties. X-ray diffraction (XRD) analysis revealed that the face-centered cubic (FCC) structure of the steel matrix was preserved up to 5% Eu2O3 reinforcement, while higher concentrations led to phase formation and crystallographic changes. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed uniform element distribution at low reinforcement levels, with particle clustering at 20% Eu2O3. Transmission factors (TFs) were evaluated using PHITS simulations for photon energies of 0.662 MeV, 1.1732 MeV, and 1.3325 MeV. The 20% Eu2O3 composite exhibited the lowest TF and highest attenuation properties, confirmed by mass and linear attenuation coefficients. Elastic modulus values decreased from 224.46 GPa in pure 316L to 189.26 GPa with 20% Eu2O3 reinforcement, reflecting the inverse relationship between mechanical stiffness and radiation shielding performance. Benchmarking against other shielding materials demonstrated superior performance of the Eu2O3-reinforced steel in gamma-ray attenuation. The 20% Eu2O3 composite shows strong potential for applications in nuclear radiation shielding where attenuation efficiency is prioritized over mechanical properties.
AtıfScopus13OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ2Application of the deep transfer learning framework for hydatid cyst classification using CT images
Gul, Yeliz; Muezzinoglu, Taha; Kilicarslan, Gulhan; Dogan, Sengul; Tuncer, Turker
Hydatid cyst, which causes important public health problems, is a disease frequently reported by radiologists. Classification of hydatid cyst types is very important to give the most suitable cure to patients. In order to decrease the misclassification rates of these cysts, machine learning is a good solution to create intelligent medical assistants. The primary objective of this work is to develop a new image classification framework to classify hydatid cyst types. Firstly, we collected a computed tomography (CT) image dataset. This CT image dataset consists of 2416 CT images with five classes (hydatid cyst types). We proposed a new deep feature engineering dataset framework for this dataset. This framework consists of (i) deep feature extraction by deploying transfer learning, (ii) iterative feature selection using INCA (iterative neighborhood component analysis), and (iii) classification. In the first phase—the feature extraction phase—we extracted deep features by deploying ten pretrained convolutional neural networks (CNNs). The used CNNs are commonly used CNNs, and the deep features have been extracted using the last pooling and fully connected layers of these networks. INCA has been applied to the generated deep features by each feature vector. k-nearest neighbors (kNN) classifier has been utilized to generate predicted values of these 10 CNNs using the selected features by INCA. Our proposed INCA-based deep feature extractor attained over 92% classification accuracy for each pretrained model. Our proposed framework reached over 92% classification accuracies, clearly demonstrating that our proposed framework is good image classification.
AtıfScopus10WoS5OpenAlex8İncele
