Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(85)
- Serdar, Osman(72)
- Güler, Ömer(68)
- Akkurt, Nevzat(61)
- Baskonus, Haci Mehmet(54)
- Alataş, Mevlüt(53)
- Paksoy, Mehmet Yavuz(53)
- Yucesan, Melih(53)
- Bulut, Hasan(51)
- Tekin, H.O.(51)
- ALMisned, Ghada(48)
- Yildirim, Numan(48)
- Benzer, Fulya(47)
- Kocabaş, Mehmet(45)
- Yildirim, Nuran Cikcikoglu(44)
- Kutlu, Banu(41)
- Ince, Muharrem(39)
- Zengin, Gokhan(39)
- Batan, Nevzat(37)
- Utku, Anıl(35)
- Celik, Erkan(33)
- Topal, Murat(32)
- Ezer, Tülay(31)
- Tanyol, Mehtap(31)
- Can, Erkan(30)
- Sulaiman, Tukur Abdulkadir(29)
- Aslan, Naim(28)
- Özkul, İskender(28)
- Aslan, Alper(27)
- Cakilcioglu, Ugur(27)
- Erguven, Gokhan Onder(27)
- Kutluyer, Filiz(27)
- Kök, Mediha(27)
- Ates, Mehmet(26)
- Erten, Fusun(26)
- Kahraman, Gökhan(26)
- Onat, Onur(26)
- Dal, Nursel Alp(25)
- Danabas, Durali(25)
- Say, Yakup(25)
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ2Investigation of thermal, crystal and magnetic behavior of addition of Nd rare earth element effect on CuAlMn shape memory alloy
Kanca, Muhammed Sait
In this study, CuAlMn alloys, a popular Cu-based shape memory alloy, were chosen because they exhibit superior shape memory properties and improved ductility compared to other Cu-based SMAs. The rare earth element Nd (neodymium) was added to CuAlMn alloy at the specified atomic percentages in the composition Cu70-xAl24Mn6Ndx(x = 0,2,4,8) and their thermal behavior, crystal structure, surface morphology and magnetic properties were investigated after fabrication. As a result of the thermal analysis measurements, it was observed that for low Nd ratios, the austenite phase transformation initial temperature of the CuAlMn alloy was increased, while at high Nd ratios, a decrease in the shape memory property was detected. Martensitic phase and precipitate phase α phase were observed in the crystal structure properties of CuAlMn alloys without and with Nd doping. These results were also detected in surface morphology observations. In addition, the crystal size decreased from 135 to 105 nm with Nd doping. As a result of magnetic measurements, CuAlMn ternary shape memory alloy was found to be paramagnetic at room temperature. Magnetic susceptibility values of the alloys showing paramagnetic magnetic properties were calculated as 11.5 × 10–6, 12.5 × 10–6, 9.15 × 10–6 and 6.15 × 10–6 emu.Oe−1.g−1, respectively. According to these results, the magnetic susceptibility value decreased with increasing Nd ratio.
AtıfScopus3WoS3OpenAlex3
İncele - MakaleAçık Erişim2024Scopus SJRQ4Ginkgo biloba L. extract and flunixin meglumine attenuate sepsis– associated liver injury, oxidative stress, inflammation and apoptosis in rats; [El extracto de Ginkgo biloba L. y la flunixina meglumina atenúan la lesión hepática, el estrés oxidativo, la inflamación y la apoptosis asociados a la sepsis en ratas]
Ak, Tuba Parlak; Gul, Burcu; Yaman, Mine; Seven, Ismail; Dagoglu, Gurdal; Gul, Huseyin Fatih
Lipopolysaccharide (LPS), known as a stimulant of inflammation, causes acute liver injury by inducing the production of inflammatory mediators and oxidative stress. The purpose of this study is to determine whether of a nonsteroidal anti–inflammatory drug (NSAID) Flunixin meglumine (FM) and herbal an medicine Ginkgo biloba L. extract (GBE) show antioxidative, anti–inflammatory or antiapoptotic effects in liver tissue in LPS–induced hepatotoxicity. Animals were separated to 6 groups as control, sepsis (1 mg·kg-1, 7th day single dose, intraperitoneal (ip)), sepsis + FM (1 mg·kg-1, 7th day single dose, ip + 2.2 mg·kg-1 day, ip), sepsis + GBE (1 mg·kg-1, 7th day single dose, ip + 50 mg·kg-1 day, gavage), FM and GBE and the study continued for 7 days. Liver tissues taken from rats sacrificed were analyzed biochemically, histologically and immunohistochemically. Accordingly, LPS caused liver function markers alteration, inflammation, oxidative stress, and apoptosis, as well as histopathological changes in liver tissue. However, it was observed that LPS–induced changes were regulated by FM and GBE application. FM and GBE was demonstrated to have antioxidant, antiinflammatory and anti–apoptotic properties in LPS– induced hepatotoxicity.
- MakaleAçık Erişim2024Scopus SJRQ2Genotypic diversity and antagonistic activities of enterococci isolated from pastırma
Ertekin, Özlem; Kaban, Güzin; Kaya, Mükerrem
The biodiversity of enterococci from pastırma (a traditional Turkish dry-cured meat product) by genotypic identification and the antagonistic activities of strains were investigated. Pastırma samples taken from 20 different small-scale factories were subjected to microbiological and physicochemical analysis. A hundred enterococci isolates were identified by 16S rRNA gene sequence analysis. To determine antagonistic activity of strains, Listeria monocytogenes and Staphylococcus aureus were used. The lactic acid bacteria and Micrococcus/Staphylococcus counts were ≥ 6 log cfu/g in 55% of the samples and 75% of the samples, respectively. Enterobacteriaceae was generally below the detectable level (< 2 log cfu/g). The enterococci count was higher than 6 log cfu/g in 30–35% of the samples, depending on the medium used. The enterococci isolates (100 isolates) were identified as E. faecium (80 strains), E. faecalis (19 strains) and E. hirae (1 strain) in genotypic identification. The nine E. faecium strains showed antagonistic activity against L. monocytogenes in the well diffusion test. In contrast, in the same antagonistic activity test, all of the strains had no antagonistic activity against S. aureus. Further studies could be planned to characterize E. faecium strains that show antagonistic activity against L. monocytogenes.
AtıfScopus2WoS2OpenAlex1
İncele - MakaleAçık Erişim2024Scopus SJRQ1Ensemble Learning Framework for DDoS Detection in SDN-Based SCADA Systems
Oyucu, Saadin; Polat, Onur; Türkoğlu, Muammer; Polat, Hüseyin; Aksöz, Ahmet; Ağdaş, Mehmet Tevfik
Supervisory Control and Data Acquisition (SCADA) systems play a crucial role in overseeing and controlling renewable energy sources like solar, wind, hydro, and geothermal resources. Nevertheless, with the expansion of conventional SCADA network infrastructures, there arise significant challenges in managing and scaling due to increased size, complexity, and device diversity. Using Software Defined Networking (SDN) technology in traditional SCADA network infrastructure offers management, scaling and flexibility benefits. However, as the integration of SDN-based SCADA systems with modern technologies such as the Internet of Things, cloud computing, and big data analytics increases, cybersecurity becomes a major concern for these systems. Therefore, cyber-physical energy systems (CPES) should be considered together with all energy systems. One of the most dangerous types of cyber-attacks against SDN-based SCADA systems is Distributed Denial of Service (DDoS) attacks. DDoS attacks disrupt the management of energy resources, causing service interruptions and increasing operational costs. Therefore, the first step to protect against DDoS attacks in SDN-based SCADA systems is to develop an effective intrusion detection system. This paper proposes a Decision Tree-based Ensemble Learning technique to detect DDoS attacks in SDN-based SCADA systems by accurately distinguishing between normal and DDoS attack traffic. For training and testing the ensemble learning models, normal and DDoS attack traffic data are obtained over a specific simulated experimental network topology. Techniques based on feature selection and hyperparameter tuning are used to optimize the performance of the decision tree ensemble models. Experimental results show that feature selection, combination of different decision tree ensemble models, and hyperparameter tuning can lead to a more accurate machine learning model with better performance detecting DDoS attacks against SDN-based SCADA systems.
AtıfScopus36OpenAlex27İncele - MakaleAçık Erişim2024Scopus SJRQ1Delamination Magmatism in Eastern Anatolia: A Geochemical Perspective
Aktağ, Alican; Sayit, Kaan; Furman, Tanya; Peters, Bradley J.
The Sr-Nd-Hf-Pb isotope geochemistry of the Late Miocene Tunceli Volcanics suggests that they are the products of mixed asthenospheric and lithospheric mantle melts. The combined elemental and mineral chemistry data additionally indicate that a pyroxenite component of lithospheric origin is involved in their genesis. Calculations favor melting depths of ∼2 GPa for the Tunceli lavas, that is, deeper than the current lithosphere-asthenosphere boundary beneath Eastern Anatolia. Geochemical data suggest that during regional Neo-Tethyan subduction, dense (i.e., pyroxenite-bearing) domains formed by progressive melt intrusion into the lower lithosphere resulted in gravitational instabilities. This unstable density configuration eventually led to the foundering of the eastern Anatolian lithosphere in the Late Miocene, resulting in progressive melting of fusible pyroxenite-bearing domains at asthenospheric depths. We demonstrate that these pyroxenitic melts mixed with ambient asthenospheric melts and generated the Tunceli lavas.
AtıfScopus7OpenAlex9İncele - MakaleAçık Erişim2024Scopus SJRQ2Regional Climate Change and Drought Dynamics in Tunceli, Turkey: Insights from Drought Indices
Korkmaz, Meral; Kuriqi, Alban
Global warming and climate change are causing temperatures to rise, which is having a negative impact on water resources. Climate change is a worldwide problem that affects and will continue to affect the frequency and intensity of natural disasters in many regions of the world. Tunceli region in Turkey, which until 10 years ago was known as an environmentally friendly city with abundant water resources and frequent rainfall, is experiencing a decrease in precipitation during the snowy winter season. This situation has made the investigation of climate change impacts an important issue in the region. Therefore, effective climate change adaptation strategies need to be developed. To determine these strategies, in this study, we assessed long-term drought conditions using multiple drought indices such as Standardized Precipitation Index (SPI), Reconnaissance Drought Index (RDI), Normal Precipitation Index (PNI), and Aridity Index (AI). The SPI and RDI analyses were performed in annual reference periods on a time scale of 3, 6, 9, and 12 months using temperature, precipitation, and evaporation data. Consequently, the SPI and RDI results were compared, and both indices show similar behavior in dry, wet, and normal seasons. Nevertheless, RDI shows less variation between different time scales, which is an advantage over SPI and is probably due to the inclusion of potential evapotranspiration in RDI. The variations in PNI between humid and dry sub-humid categorizations throughout the years, combined with the AI results, indicate that the Tunceli region predominantly experiences a climate ranging from dry sub-humid to semi-arid. This study could help decision-makers take effective measures to become more resilient to climate change in temperate climate regions and take important steps toward sustainable water resources management.
AtıfScopus17WoS15OpenAlex20İncele - MakaleYalnız künye2024Scopus SJRQ2Mechanical and thermal properties of short banana fiber reinforced polyoxymethylene composite materials dependent on alkali treatment
Doğan, Akar; Güneş, Çağdaş
The present study aimed to develop a recyclable composite material based on a natural product, namely banana fiber, instead of synthetic reinforcement elements such as glass fiber or carbon fiber in thermoplastic matrix composites employed in many aspects of daily life. Polyoxymethylene (POM) thermoplastic was used as the matrix material. 3 %, 6 %, and 9 % by weight short natural banana fiber was used as reinforcement. Furthermore, the study improved the mechanical and thermal properties of the composite material with chemical improvements based on alkali treatment of banana fiber. Banana fiber and POM was initially mixed mechanically and then extruded at temperatures between 170 and 190 °C to obtain a homogeneous mixture. The mixture obtained by extrusion was initially cooled in the cooling pool and then passed through the crusher to obtain granules. These granules were pressed in plastic injection molds to obtain standard test samples. The ratio of reinforcement material and the variations in mechanical and thermal properties of the composites induced by the alkali treatment are presented in figures and tables. Furthermore, the changes in cross-sectional material images were examined with electron microscopy scans. The tensile and flexural strength of the material improved with alkali treatment.
AtıfScopus21WoS19OpenAlex20İncele - MakaleYalnız künye2024Scopus SJRQ1The effects of listening to lullabies and self-selected music at home on prenatal stress and anxiety in nulliparous pregnant women: A randomized-controlled study
Baltacı, Nazlı; Doğan Yüksekol, Özlem; Koç, Emine; Ulucan, Mihriban
To compare the effects of nulliparous pregnant women listening to lullabies and self-selected music on reducing the anxiety and antenatal stress. This was a randomized controlled study. Lullaby group (LG) (n = 40) listened to the lullaby chosen by the researcher, mixed music group (MG) (n = 40) listened to self-selected music and control group (CG) (n = 40) received general care. Post-test anxiety and stress levels was lower in two intervention groups versus CG (p < 0.01). Post-test anxiety was lower in the MG versus LG (p < 0.01), however post-test stress levels were similar. Pregnant women listening to self-selected music at home is more effective in reducing anxiety.
AtıfScopus6WoS7İncele - MakaleYalnız künye2024Scopus SJRQ2Plant extract-based biosynthesis of silver nanoparticle and silver–zinc nanocomposites-doped hydroxyapatite and its antimicrobial activity
Unal, Ilkay; Aydoğdu, Burcu; Aytar, Mehmet
Hydroxyapatite (HAp) is an essential material in the biomedical field because of its chemical composition, similar to the apatites found in bones. The lack of bactericidal properties of HAp-based materials cannot prevent the adhesion and growth of bacteria. However, it can develop composite biomaterials using nanoparticles (NPs) such as silver (Ag) and zinc (Zn), which exhibit biocidal behaviours to control resistant microorganisms. This study aimed to prepareHAp–AgNPs and HAp–Ag@ZnNPs nanocomposite and evaluate their antimicrobial properties against Gram-positive and Gram-negative bacteria. HAp powders were produced from sheep bone. An aqueous extract of Marrubium astracanicum was used as a reducing and stabilising agent for the synthesis of NPs. The composites were characterized by XRD, SEM–EDX, SEM and FTIR. In vitro biocompatibility assessment was determined by agar well diffusion tests. The HAp–Ag@ZnNPs nanocomposites showed stronger antimicrobial activity than HAp–AgNPs against bacteria and fungi, while pure HAp did not show any effect.
AtıfScopus6WoS5OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ3Exploring Sorbus torminalis Leaves: Unveiling a Promising Natural Resource for Diverse Chemical and Biological Applications
Ak, Gunes; Tüfekci, Enis Fuat; Mustafa, Ahmed M.; Caprioli, Giovanni; Altunoglu, Yasemin Celik; Baloglu, Mehmet Cengiz; Cakılcıoglu, Ugur; Polat, Rıdvan; Darendelioglu, Ekrem; Zengin, Gokhan
Sorbus torminalis (L.) Crantz has a rich history of versatile applications spanning the fields of medicine and nutrition. It is noteworthy that the decoction obtained from S. torminalis leaves is a traditional treatment method against both diabetes and stomach disorders. Phytochemical profiling determined by HPLC/MS-MS. The effects of the extracts on cell viability were investigated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method against MDA-MB-231 cell line (human breast adenocarcinoma).The ethanol/water extract contained more concentration of total phenolic (91.41 mg gallic acid (GAE) equivalent /gr) and flavanoid (29.10 mg rutin (RE) equivalent/gr) in the tested extract (p<0.05). Resulting of HPLC analysis, the chemical constituents varied depending on the solvents and chlorogenic acid, hyperoside, isoquercetin, delphindin-3,5-diglucoside, procyanidin B2, epicatechin, neochlorogenic acid, 3,5-dicaffeoylquinic acid were identified in all extracts. Overall, ethanol, n-hexane and ethyl acetate extracts showed the highest inhibition for the tyrosinase enzyme. The effect of leaf extracts of S. torminalis on antimicrobial, biofilm inhibitory, and anticancer activities was examined. Based on outcomes of our study recognize this plant as a critical source of medically active chemicals for feasible phytopharmaceutical and nutraceutical applications, providing the first scientific insight into the detailed biological and chemical profiles of S. torminalis.
AtıfScopus7OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ2Leachate treatment via electrocoagulation–coal-based powdered activated carbon process: Efficiencies, mechanisms, kinetics, and costs
Ogedey, Aysenur; Oguz, Ensar
This study aims to improve COD, NH3-N, and turbidity removal from Bingöl's leachate using a single-reactor integrated electrocoagulation (EC)–coal-based powdered activated carbon (CBPAC) process under various experimental conditions. In the EC-CBPAC process, three stainless-steel cathodes and three aluminum electrodes were connected to the negative and positive terminals of the power supply, respectively. The initial concentrations in the leachate were 1044 mg O2/L for COD, 204 mg/L for NH3-N, and 57 NTU (or 71.25-mg (NH2)2H2SO4/L) for turbidity, respectively. After a 40-min EC-CBPAC process, with a CBPAC dosage of 5 g/L and pH of 5 for COD and turbidity, and 9.5 for NH3-N, the optimum removal efficiencies for COD, NH3-N, and turbidity were achieved at 92%, 40%, and 91%, respectively. When the EC process was applied without CBPAC under the same experimental conditions, the removal efficiencies of COD, NH3-N, and turbidity were 87%, 28%, and 54%, respectively. Before and after the EC-CBPAC process, the Brunauer–Emmett–Teller (BET) surface area, pore volume, and mean pore diameter of the CBPAC were found to be (888 m2/g, 0.498 cm3/g, and 22.28 Å) and (173 m2/g, 0.18 cm3/g, and 42.8 Å), respectively. The optimum pseudo-first-order (PFO) rate constants for COD, turbidity, and NH3-N were determined to be 3.15 × 10−2, 4.77 × 10−2, and 8.8 × 10−3 min−1, respectively. With the current density increasing from 15 to 25 mA/cm2, energy consumption, unit energy consumption, and total cost increased from 68.7 to 122.4 kWh/m3, 6.948 to 15.226 kWh/kg COD, and 0.85 to 1.838 $/kg COD, respectively. Practitioner points: EC-CBPAC process has greater COD, NH3-N, and turbidity removal efficiency than EC process. COD and turbidity achieved their optimum disposal efficiencies at 92% and 91%, respectively, at pH 5 The most efficient disposal efficiency for NH3-N was observed to be 40% at pH 9.5. EC-CBPAC process increased removal efficiencies for COD, NH3-N, and turbidity by 20%, 19%, and 38%, respectively, compared with EC alone. The turbidity, NH3-N, and COD disposal fitted PSO model due to high correlation values (R2 0.94–0.99).
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Activity of nanosized copper-boron alloys against Phytophthora species
Yiğit, Uğur; Türkkan, Muharrem; İlhan, Hasan; Şimşek, Tuncay; Güler, Ömer; Derviş, Sibel
This study aimed to evaluate the antifungal activity of copper-boron (Cu-B) nanoalloys against a range of Phytophthora species, including P. capsici, P. citrophthora, P. palmivora, P. cinnamomi, P. nicotianae, P. cactorum, P. plurivora, P. inundata, and P. megasperma. The nanoalloys were synthesized via mechanical alloying under an argon atmosphere, resulting in the formation of nanocrystalline Cu-B nanoalloys with irregular morphology and particle sizes ranging from 50 to 240 nm. At a concentration of 250 µg mL−1, the Cu-B nanoalloys demonstrated complete inhibition of mycelial growth, sporangium production, and zoospore germination in all tested Phytophthora species. The EC50 values for mycelial growth ranged from 28.02 to 120.17 µg mL−1, while for sporangium production and zoospore germination, they were below 10 µg mL−1. Furthermore, the nanoalloys exhibited fungicidal activity against specific Phytophthora species, such as P. capsici, P. citrophthora, P. inundata, and P. megasperma, at concentrations of 100, 250, 250, and 250 µg mL−1, respectively. Notably, the Cu-B nanoalloys displayed significant protective and curative effects on tuber rot severity in P. nicotianae-inoculated potatoes, resulting in reductions of 94.13% and 92.61% compared to the control, respectively, at a concentration of 10 µg mL−1 (P < 0.05). These findings highlight the potential of Cu-B nanoalloys as a promising fungicide for the management of plant diseases caused by Phytophthora spp.
AtıfScopus3WoS1OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ1Work stress and obsessive-compulsive symptoms in nurses and office workers: a comparative study
Kuzu Durmaz, Ayşe; Çiçekoğlu Öztürk, Pınar; Çevik Durmaz, Yadigar
Objectives. This study aims to compare the work stress and obsessive-compulsive symptoms of nurses and office workers and to determine the relationship between work stress and obsessive-compulsive symptoms. Methods. A total of 127 nurses and 127 office workers participated in the cross-sectional study and comparative study. Data were collected using the perceived work stress scale and the Maudsley obsessive-compulsive inventory. Results. Nurses had higher work stress scores (p = 0.003) in general than office workers. In particular, nurses with a low (p < 0.039) and average (p < 0.007) economic status, nurses who had been employed for 1–10 years (p < 0.001) and nurses working 40 h per week (p < 0.042) had higher work stress scores than office workers. There was no difference (p > 0.05) between obsessive-compulsive symptom scores. There was a positive significant relationship (p < 0.001) between work stress and obsessive-compulsive symptom scores of nurses and office workers. Work stress explains 6.1% of the obsessive-compulsive symptoms in nurses and 12.4% in office workers. Conclusion. The results of this study concluded that work stress of nurses is higher than that of office workers and work stress affects the obsessive-compulsive symptoms in both groups.
AtıfScopus4WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Exploring thermodynamic, physical and radiative interaction properties of quinary FeNiCoCr high entropy alloys (HEAs): a multi-directional characterization study
ALMisned, Ghada; Guler, Omer; Ozkul, Iskender; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.
To qualify for nuclear applications, materials must meet specific criteria, including mechanical properties, high-temperature behavior, corrosion resistance, and high-temperature oxidation resistance. High Entropy Alloys (HEAs) are particularly suitable for these applications due to their unique properties. Consequently, we conducted a theoretical and simulation-based approaches to assess some critical properties including radiation shielding properties of some quinary FeNiCoCr HEAs. In this study, we focused on quinary FeNiCoCr HEAs, whose corrosion properties have been previously examined in the literature. We investigated the thermodynamic and radiation shielding properties of HEAs with sixteen different compositions. Our methodology included evaluating thermodynamic parameters such as Mixing Entropy (∆Smix) and Mixing Enthalpy (∆Hmix), as well as structural characteristics like Valence Electron Concentration (VEC) and Atomic Size Difference (δ). This allowed us to systematically deduce the phase behavior and stability of various HEAs. Through computational modeling, we assessed the radiation shielding capabilities of these alloys, particularly their effectiveness in attenuating gamma ray and fast neutrons. The results identified FeNiCoCrW as the alloy with the lowest fast neutron removal cross-section values, highlighting its potential for nuclear applications. Its high melting point and the synergistic interplay between its elemental composition and thermodynamic properties suggest broad applicability in extreme environments. Thus, FeNiCoCrW emerges as a promising HEA with multifunctional capabilities, warranting further exploration and potential integration into advanced engineering solutions.
AtıfScopus8OpenAlex10İncele - MakaleAçık Erişim2024Scopus SJRQ1Investigation of the effect of electrophoresis-assisted milling on machinability
Mahmat, Aybars
In this study, the electrophoresis-assisted milling (EAM) method, an alternative method to the conventional milling (CM) method, was proposed to increase the machinability of Ti6Al4V alloy, which is difficult to machine. The nanoparticles in the electrophoresis solution generated an electric field. This electric field collected abrasive particles around the cutting tool, and the machining quality was improved. The impacts of different cutting parameters on the performance characteristics were examined using both EAM and CM methods. The experimental results demonstrate that the proposed EAM method significantly improves these performance characteristics. In addition, increasing spindle speed increased tool wear and cutting temperature for both machining methods; It was observed that it reduced cutting force and surface roughness. It was concluded that as the feed rate increased, tool wear, cutting temperature, cutting force, and surface roughness increased. The experimental results showed that feed rate, machining method, and spindle speed affect machining quality. In conclusion, the experimental results significantly impact improving the machining performance of the EAM method.
AtıfScopus1WoS2OpenAlex2İncele - MakaleYalnız künye2024Scopus SJRQ4A parallel vector field on Riemannian manifolds admitting semi-symmetric non-metric connection
Barman, Ajit; Ünal, Inan
In this paper, we study Riemannian manifolds admitting a type of semi-symmetric nonmetric connection. By taking the characteristic vector field of this connection as a parallel vector field via the Levi-Civita connection, we examine some curvature properties of Riemannian manifolds. We discuss Ricci-semi symmetry and we consider the conformal curvature tensor. Finally, we study hypersurfaces of Riemanninan manifolds admitting a type of semi-symmetric non-metric connection with a parallel characteristic vector field. We take an example of a Riemannian manifold and we apply our results.
- MakaleYalnız künye2024Scopus SJRQ2Contact analysis in functionally graded layer loaded with circular two punches
Polat, Muhammed T.; Polat, Alper
In this study, contact analysis in a functionally graded (FG) layer loaded with two circular punches is solved using the finite element method (FEM). The problem is consisted of a functionally graded layer that resting on an elastic semi-infinite plane and is loaded with two rigid punches of circular geometry. External loads P and Q are transferred to the layer via two rigid punches. The finite element model of the functionally graded layer is created using the ANSYS package program and a 2-dimensional analysis of the problem is analyzed. The contact lengths, obtained as a result of the analysis are compared with the analytical solution in the literature. In the study, the effects of parameters such as distances between punches, loads, inhomogenity parameter on contact zones, initial separation loads and distances, normal stresses, stresses across depth and contact stresses are investigated. As a result, in this study, it can be said that the magnitude of the stresses occurring in the FG layer is less than the homogeneous layer, therefore the life of FG materials will be longer than the homogeneous layer. When the distance between the punches is 2.25, the initial separation distance is 6.98, and when the distance between the punches is 4, the initial separation distance decreases to 6.10. In addition, when the load increased in the second punch, the initial separation load decreased from 55 to 18. The obtained results are presented in the form of graphs and tables.
AtıfScopus1WoS1İncele - MakaleYalnız künye2024Scopus SJRQ2Stress–strength reliability for electricity systems based on the Bernstein copula approximation
Susam, Selim Orhun; Hudaverdi, Burcu
Electricity is a critical resource for modern society, and its availability is essential for various aspects of daily life, from powering homes to supporting industrial processes and infrastructure. Ensuring a reliable supply of electricity is vital for economic stability and the well-being of a population. As the world moves toward more sustainable and renewable energy sources, understanding the reliability of these sources compared to traditional fossil fuels is crucial. In this study, we develop a methodology that enables the measurement of stress–strength reliability when electricity consumption is considered as the strength variable, positioned between electricity generation from renewable energy sources and fossil fuels as stress variables. We achieve this using the copula-based reliability with Bernstein copula approximation. The methodology is applied to the U.S. monthly electricity data. The result shows that the current rates of electricity output from fossil fuels and renewables will not be sufficient to meet the demand for electricity.
AtıfScopus2WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Some nanotoxicity effects of copper (60-80 nm) and copper oxide (40 nm) nanoparticles on Artemia salina
Cimen, Isıl Canan Cicek; Danabas, Durali; Ates, Mehmet
In this study, nanotoxicity tests were made by exposure of Artemia salina to copper (Cu 60-80 nm) and copper oxide (CuO 40 nm) nanoparticles (NPs) at different concentrations (0.2, 1, 5, 10, 25, and 50 mg/L). The LC50 value of Cu (60-80 nm) NPs on the A. salina individuals at the beginning (0), 24th, 48th and 72nd hours and elimination period was 52.37 mg/L while the LC50 value of CuO (40 nm) NPs was 55.39 mg/L. The results of UV-Vis absorbance values showed that all statistical data revealed that maximum effect was observed between 24-30 hours and 25 ppm absorbance concentration was more effective. The multiple R, correlation coefficient (R2) and adjusted R2 values of Cu NP for the suitable Quadratic model were, respectively; 92.96 %, 86.42 % and 76.71 % while they are 98.31 %, 96.64 % and 94.25 % for CuO NP. Also, the data, was indicated effect size significantly changed based on the type and size of NP. Considering the microscope results, it was clearly noticed that A. salina organisms took the NPs in to their body. The accumulation in the gut of A. salina was observed and the images were taken with phase contrast microscope for both of NPs. The highest decrease for survival rates of A. salina individuals exposed to Cu NP was observed in the 10 ppm concentration (43.47 %) and in the 5 ppm concentration (46.20 %) for CuO NP. The results revealed that Cu and CuO NPS showed different toxic effects and that Cu NPs were more toxic than CuO.
AtıfScopus2WoS2İncele - MakaleYalnız künye2024Scopus SJRQ2Production of high entropy (FeNiMnCrV)3O4 oxide by mechanical alloying process and electrochemical performance analysis for Li-ion cells
Dogan, Ebru; Altin, Serdar; Guler, Seval Hale; Guler, Omer; Altin, Emine
In this study, a high entropy oxide material was fabricated from its alloy using mechanical alloying technique in the form of (FeNiMnCrV)3O4 with a symmetry of Fd-3m, and their structural properties were investigated by XRD, SEM-EDS dot mapping, and XPS analyses. The EDS analysis results of oxide and alloy show that Fe, Ni, Mn, Cr, and V have similar ratios for both samples. The elemental ratios were also measured by ICP-MS and the results support the EDS and XPS data. The alloy and oxide powders were used for the production of the anode materials for the half-cell configuration of the battery. The CV analysis of both cells showed that they have similar characteristic redox reactions and the main difference between the two electrodes is the current density values in the peaks. The initial capacity value of the (FeNiMnCrV)3O4 for 10 mA/g was found as 1070 mAh/g for the first cycle which is promising results as an anode material for Li-ion cells.
AtıfScopus3WoS3OpenAlex3İncele