Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(82)
- Akkurt, Nevzat(67)
- Güler, Ömer(66)
- Baskonus, Haci Mehmet(62)
- Bulut, Hasan(60)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(43)
- Yildirim, Numan(42)
- Yildirim, Nuran Cikcikoglu(38)
- Paksoy, Mehmet Yavuz(36)
- Serdar, Osman(36)
- Zengin, Gokhan(36)
- Ince, Muharrem(34)
- Celik, Erkan(33)
- Benzer, Fulya(32)
- Kocabaş, Mehmet(30)
- Sulaiman, Tukur Abdulkadir(30)
- Tanyol, Mehtap(29)
- Yildirim, Ozal(28)
- Aslan, Naim(26)
- Kök, Mediha(26)
- Özkul, İskender(26)
- Ates, Mehmet(25)
- Danabas, Durali(25)
- Kutluyer, Filiz(25)
- Can, Erkan(24)
- Kutlu, Banu(23)
- Onat, Onur(23)
- Demir, Veysel(22)
- Erten, Fusun(22)
- Guler, Omer(22)
- Say, Yakup(22)
- Güler, Seval Hale(21)
- Yaman, Mehmet(21)
- Baykal, Duygu Sen(20)
- Sançar, Taylan(20)
- Susam, Selim Orhun(20)
- Cakilcioglu, Ugur(19)
- Orhan, Cemal(19)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ3Eco-Friendly and Practical Electrochemical Determination of Lactic Acid in Milk Using Boron Doped Diamond Electrode
İpek, Yeliz.; Koçak, Berna; Keçeci, Ali
In this study, an economical, environmentally friendly, sensitive, selective, and rapid voltammetric quantitative analysis method was developed using a boron doped diamond electrode to determine lactic acid (LA). Two linear working ranges were determined for LA determination in phosphate buffer solution (PBS, pH of 2). The first linear working range (LR1) was between concentrations of 1.5 × 10−6–8 × 10−6 mol· L−1, with a detection limit of 1.3 × 10−6 mol·L−1, and the limit of quantification (LOQ) was found to be 4.4 µmol· L−1. The second linear working range (LR2) was determined in the concentration range of 8.0–89.2 µmol·L−1. LOD was calculated as 15.8 µmol·L−1, and the LOQ value was calculated as 52.6 µmol·L−1 in the LR2. Intraday repeatability of the BDD electrode for LA determination was (RSD) 6.8% in LR1 and 11.8% in LR2. The interday repeatabilities of the BDD electrode in LR1 and LR2 were calculated as 7.7% and 4.7%, respectively. The developed electrochemical sensor was successfully applied for the determination of LA in milk sample. The sensor exhibited a short response time of about 10 s in PBS at pH 2. The recovery values of LA in PBS and milk sample were 97.3% and 96.1%, respectively.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleYalnız künye2025Scopus SJRQ2The impact of global value chains on climate change
Ateş, Erdem; Şanlısoy, Selim
Climate change can be defined as the increase in average temperatures due to rising greenhouse gas (GHG) emissions, predominantly due to human activities. Carbon emissions have increased at an alarming rate with the emergence of globalization, with its accompanying global value chain, and the consequent increase in global production volume with its polluting sectors. To combat this alarming situation, production with environmentally friendly technologies has emerged recently, and developing countries are embracing more and more costly environmentally friendly production techniques, although they are disadvantaged when it comes to covering the costs. However, it has been observed that they stay behind in this race to adopt environmentally friendly techniques compared to developed countries. The aim of the study, which is a novel contribution to the existing literature, is to examine the relationship between the global value chain and climate change by considering the distinction between developed and developing countries. The study used the data of 156 countries from the years 2000–2018. The results obtained from the generalized method of moments (GMM) show that participation in global value chains has different effects in developed and developing countries regarding carbon emissions. When the level of participation in GVC (global value chain) and FVA (foreign value added) increases, countries’ carbon emissions decrease, and it increases when the DVA (domestic value added) level increases. As a result, in particular, developing countries should green their production methods, and for this purpose, financial support mechanisms should be established.
AtıfScopus8WoS4OpenAlex7İncele - MakaleAçık Erişim2025Scopus SJRQ1Transauricular vagal nerve stimulation suppresses inflammatory responses in the gut and brain in an inflammatory bowel disease model
Atalar, Kerem; Alim, Ece; Yigman, Zeynep; Belen, Hayrunnisa Bolay; Erten, Fusun; Sahin, Kazım; Soylu, Ayse; Dizakar, Saadet Ozen Akarca; Bahcelioglu, Meltem
Inflammatory bowel disease (IBD) encompasses Crohn's disease (CD) and ulcerative colitis (UC), is a major health problem on a global scale and its treatment is unsatisfactory. We aimed to investigate the effects of transauricular vagal nerve stimulation (tVNS) on inflammation in rats with IBD induced by trinitrobenzene sulfonic acid (TNBS). A total of 36 adult female Sprague–Dawley rats were given TNBS, or vehicle, and tVNS, or sham, every other day for 30 min for 10 days. Postmortem macroscopic and microscopic colon morphology were evaluated by histological staining. Additionally, IL-1β, IL-6, IL-10, and TNF-α cytokine levels in the colon and the brain were evaluated by immunohistochemistry and western blotting analysis. TNBS induced epithelial damage, inflammation, ulceration, and thickened mucosal layer in the colonic tissues. Administration of tVNS significantly ameliorated the severity of TNBS-induced tissue damage and inflammatory response. TNBS also alters pro-inflammatory and anti-inflammatory balance in the brain tissue. TVNS application significantly suppressed the protein levels of pro-inflammatory cytokines, namely IL-1β, IL-6, and TNF- α while augmenting the level of anti-inflammatory cytokine IL-10 in the colonic and the brain tissue. We have shown that TNBS-mediated colonic inflammation and tissue damage are associated with neuroinflammatory responses in the brain tissue. Also demonstrated for the first time that neuroinflammatory response in the gut-brain axis is suppressed by tVNS in the IBD model. Non-invasive tVNS stands out as a new potential treatment option for types of IBD.
AtıfScopus13OpenAlex12
İncele - MakaleYalnız künye2025Scopus SJRQ2Heat transfer and condensation analysis of the walls of a house built with natural andesite stone
Işik, Erdem; Kahraman, Gökhan; Atalar, Aydın
The use of natural stones in buildings is increasingly popular due to both their decorative appearance and their thermal performance. Proper use of these stones in buildings is crucial for energy conservation and preventing condensation within structural components. This study investigated heat transfer and condensation in the wall of a house made from natural andesite stone in Iğdır, Turkey, under steady-state conditions and different wall combinations. Samples were created from natural stones extracted from two different elevations in the foothills of Mount Ararat, with measured thermal conductivity values of 1.73 W/m·K (higher elevation– Haverage) and 1.31 W/m·K (lower elevation– Laverage). In the wall model using a 3-cm thick insulation board between two natural stones from the higher elevation, condensation occurred on the outer surface of the insulation layer. This can negatively impact the durability and thermal performance of the structure, and such design should be avoided. The highest heat flux of 18.27 W/m² was observed in the non-insulated wall made of higher elevation stones, while the lowest heat flux of 6.68 W/m² occurred in the model using a 3-cm insulation board between two lower elevation stones. No condensation risk was found in this configuration. The difference between the worst and best cases in terms of heat flux was approximately threefold, emphasizing the importance of proper material selection and insulation design. These findings provide guidance for energy-efficient building design using natural stone.
- MakaleAçık Erişim2025Scopus SJRQ2Synthesis and characterization of novel bis(thiosemicarbazone) complexes and investigation of their acetylcholinesterase and glutathione S-transferase activities with in silico and in vitro studies
Donmez, Melike; Sekerci, Memet; Adiguzel, Ragip; Oğuz, Ercan; Türkan, Fikret; Yildiko, Umit; Colak, Naki
In this study, firstly, bis(thiosemicarbazone) ligand [L: 2,2′-(2-(2-(4-methoxyphenyl)hydrazineylidene)cyclohexane-1,3-diylidene)bis(hydrazine-1-carbothioamide)] was synthesized by the condensation reaction of thiosemicarbazide and ketone compound (2-(2-(4-methoxyphenyl)hydrazone)cyclohexane-1,3-dione). The metal complexes were synthesized by the reaction of obtained ligand (L) with CuCl2·2H2O, NiCl2·6H2O, CoCl2·6H2O, and MnCl2·4H2O salts. The structures of synthesized ligand and their complexes were characterized using elemental analysis, IR, UV–Vis, 1H-NMR spectra, 13C-NMR spectra, magnetic susceptibility, mass spectra (LC–MS), thermogravimetry analysis-differential thermal analysis (TGA-DTA), and differential scanning calorimetry techniques. According to the results of the analysis, square plane geometry was suggested for Cu and Co complexes. However, the structures of Ni and Mn complexes were in agreement with octahedral geometry. Molecular docking analysis and pharmacological potential of the compound were evaluated to determine the inhibitory potential against acetylcholinesterase (AChE) and Glutathione-S-transferases (GST) enzymes. The compound exhibited strong binding/docking indices of − 5.708 and − 5.928 kcal/mol for the respective receptors. In addition, L–Ni(II) complex was found to be the most effective inhibitor for AChE enzyme with a Ki value of 0.519. However, with a Ki value of 1.119, L–Cu(II) complex was also found to be an effective inhibitor for the GST enzyme.
AtıfScopus21OpenAlex19İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluation of Green Deal compliance performance with a hybrid comparative multi-attribute decision model
Karadag, Mehmet; Gul, Muhammet; Yucesan, Melih; Ortiz-Barrios, Miguel; Ishizaka, Alessio; Khan, Jehangir
The environmental and economic transformation initiated by the European Green Deal is influencing not only EU member states, but also other countries engaged in trade with the EU. This transformation mandates a shift towards sustainable practices in sectors such as agriculture, industry, transportation, energy, and finance. Compliance with the Green Deal is increasingly crucial for countries, particularly those with significant commercial ties to the EU. However, differing levels of development lead to varying degrees of implementation. While studies on the Green Deal compliance of EU member states exist, an evaluation of Türkiye—a candidate EU member with substantial trade relations—would address a significant gap in the literature. This study introduces a novel hybrid comparative multi-attribute decision model that combines subjective (Best Worst Method and its derivatives) and objective (Entropy) weighting to determine the relative importance of 14 sub-criteria under three main criteria: “Reducing” the impacts of climate change, “Protecting” the planet and health, and “Enabling” a green and just transition. Using the Ratio Product Model (RPM), Türkiye's Green Deal compliance from 2017 to 2021 was evaluated. Sensitivity analysis was conducted to validate the robustness of the findings, and comparisons were made using various multi-attribute decision models, including SAW, TOPSIS, and VIKOR, as well as benchmarking against EU countries. The criteria weights, derived from a combination of subjective and objective methods, highlighted the dominant importance of the “Reducing” criterion across all methods. The “Enabling” and “Protecting” criteria showed slight variations in importance depending on the method. The RPM results indicated that 2021 was Türkiye's best-performing year in terms of Green Deal compliance, while 2017 showed the weakest performance. Despite some fluctuations between 2018 and 2019, Türkiye demonstrated significant progress overall. The study not only advances the methodology for evaluating Green Deal compliance but also provides actionable insights for policymakers and industry stakeholders, enabling more informed decision-making. By highlighting Türkiye's trajectory, the findings offer strategic guidance for non-EU countries aiming to align with Green Deal objectives, fostering sustainable development and strengthening economic ties with the EU.
AtıfScopus11OpenAlex11İncele - MakaleYalnız künye2025Scopus SJRQ3Development of alternative carbon fibre powder and rare earth element-based filler for high density polyethylene; [Entwicklung von alternativen Kohlenstofffaserpulvern und Seltene Erden-basierten Füllstoffen für Polyethylen hoher Dichte]
Ayikurt, P.; Kısmet, Y.; Dogan, A.; Höchstötter, K.H.; Fiedler, B.
This study developed alternative fillers to enhance the flowability of high-density polyethylene (HDPE). Lanthanum and cerium oxide with over 90 % purity were used as binder interfacial elements in fillers developed using both carbon fiber powder wastes and powder coating wastes. Polyethylene gel was used to make the fillers thermoplastic and homogenous. A total of six different fillers were developed and melt flow index analyses were performed. As a result of these analyses, it was found that the fluidity of high-density polyethylene improved significantly, especially with fillers containing carbon fiber powder. As a result, high-density polyethylene mixtures containing 10 %, 20 %, 30 %, 40 %, and 50% by weight of carbon fiber powder-based fillers were pressed into molds by a plastic injection molding machine, and samples were produced. According to the mechanical analysis results of these specimens, tensile and flexural strengths decreased slightly depending on the filling ratio, while the impact strengths remained constant. Differential scanning calorimetry analysis was performed to determine the glass transition temperature and melting/crystallization temperatures of the obtained mixtures, while thermogravimetric analysis was performed to determine the mass losses. At the same time, electron microscope analysis of the cross sections of the samples were performed.
- MakaleAçık Erişim2025Scopus SJRQ1Assessing Motor Performance and Ankle Mobility in Pre-Adolescent Male Fencers
Aydin, Yalcin; Tokgoz, Gurkan; Yilmaz, Nurkan; Coskun, Ilgin Ali; Beykumul, Aysegul; Colak, Enes; Aygoren, Caner; Koc, Samet; Cinarli, Fahri Safa
Ankle mobility plays a critical role in dynamic stability and propulsion during fencing-specific actions. However, its relationship to performance metrics in young athletes remains unclear. This study aimed to investigate the relationship between ankle range of motion (ROM), acceleration, and jump height in pre-adolescent male fencers, as well as to examine bilateral differences in ankle mobility between the front and rear foot. Fifteen fencers (age 10.86 ± 0.91 years) were assessed for ankle ROM (dorsiflexion, plantar flexion, inversion, eversion) using a goniometer. Performance tests included a 7 m sprint lunge (acceleration) and countermovement jump. Significantly large correlations were observed between front and rear foot ankle plantar flexion range of motion and both acceleration (r = 0.625–0.628, p < 0.05) as well as vertical jump height (r = 0.579–0.647, p < 0.05). Rear foot ankle plantar flexion range of motion significantly predicted acceleration (r2 = 0.335, p < 0.05) and jump height (r2 = 0.418, p < 0.05). In contrast, no meaningful associations were found between dorsiflexion, inversion, or eversion range of motion and performance metrics. Additionally, bilateral comparisons revealed significantly greater dorsiflexion in the front foot ankle and greater eversion in the rear foot ankle (p < 0.05). Plantar flexion ROM is a key contributor to acceleration and jump capacity in youth fencers. Incorporating ankle mobility training may support physical development in this population.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Effects of Integrated Extracts of Trigonella foenum-graecum and Asparagus racemosus on Hot Flash-like Symptoms in Ovariectomized Rats
Erten, Fusun; Er, Besir; Ozmen, Ramazan; Tokmak, Muhammed; Gokdere, Ebru; Orhan, Cemal; Morde, Abhijeet A.; Padigaru, Muralidhara; Sahin, Kazim
Vasomotor symptoms, such as hot flashes (HFs), commonly affect women during menopause, leading to a reduced quality of life. The current study evaluates the combined effect of active components Asparagus racemosus (AR) and Trigonella foenum-graecum (TFG) in a single oral formulation (IAT) for alleviating menopausal symptoms in ovariectomized rats. Following bilateral ovariectomy, the animals were randomly assigned to nine groups: (1) Control, (2) Ovariectomy (OVX), (3) OVX+TA1 (TA: Combination of Trigonella and Asparagus; TFG 30 mg/kg + AR 30 mg/kg), (4) OVX+TA2 (TFG 30 mg/kg + AR 15 mg/kg), (5) OVX+TA3 (TFG 15 mg/kg + AR 30 mg/kg), (6) OVX+TA4 (TFG 40 mg/kg + AR 30 mg/kg), (7) OVX+TA5 (TFG 30 mg/kg + AR 40 mg/kg), (8) OVX+IAT1 (IAT: Integrated Asparagus and Trigonella; TFG+AR integrated extract, 30 mg/kg), and (9) OVX+IAT2 (TFG+AR integrated extract, 60 mg/kg). On the 8th day of treatment, tail and skin temperatures were recorded every 30 min for 24 h. Ovariectomized rats exhibited menopausal symptoms, such as hormonal imbalances and elevated skin temperature. Administration of AR, TFG, and IAT significantly decreased serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and cortisol while increasing estradiol, progesterone, and dopamine (p < 0.0001), effectively alleviating hot flash-like symptoms. Additionally, they mitigated ovariectomy-induced oxidative stress by lowering malondialdehyde (MDA) levels and restoring antioxidant enzyme activity. Ovariectomized rats exhibited increased expression of a proto-oncogene (c-FOS), gonadotropin-releasing hormone (GnRH), Kisspeptin, Neurokinin B (NKB), and Transient receptor potential vanilloid 1 (TRPV1), along with reduced expressing brain-derived neurotrophic factor (BDNF) levels, which were reversed by treatment, especially with the IAT2 combination. The AR and TFG combination, particularly in IAT formulations, showed strong potential in alleviating menopausal symptoms in ovariectomized rats. These findings suggest that the combination of AR and TFG extracts could be a natural alternative for managing postmenopausal symptoms by restoring reproductive hormone levels, regulating lipid profiles, and enhancing antioxidant defense systems.
AtıfScopus8WoS8OpenAlex6İncele - MakaleYalnız künye2025Scopus SJRQ2Effects of Trace Rare Earth (TRE) additions on thermal, crystal structure, and radiation shielding properties of CuAlMn high-temperature S-M alloys: A closer look at Cerium effect
Kalay, Ece; Özkul, İskender; Karaduman, Oktay; Kızılgün, Yasin; Güler, Ömer; Canbay, Canan Aksu; Kilic, G.; Baykal, Duygu Sen; ALMisned, Ghada; Tekin, H.O.
This study systematically investigates the effect of Ce addition on the thermal, structural, and radiation shielding properties of CuAlMn-based high-temperature shape memory alloys (HTSMAs). Among the different compositions, Ce-III demonstrated the most balanced performance, exhibiting optimized phase transformation behavior, microstructural refinement, and enhanced gamma-ray attenuation. Differential Scanning Calorimetry (DSC) analysis revealed that Ce-III exhibited lower transformation temperatures, with austenite start (As) and finish (Af) temperatures of 378.13 °C and 429.75 °C, respectively, and martensite start (Ms) and finish (Mf) temperatures of 402.52 °C and 341.91 °C, suggesting improved thermal stability. Microstructural analysis indicated significant grain refinement, attributed to Ce's dislocation pinning effect, which contributed to enhanced strength and radiation attenuation. X-ray diffraction (XRD) patterns confirmed the formation of Ce-rich intermetallic phases, such as Mn1.15Cu3.85Ce and Cu8Ce4, which increased density and photon interaction probability. The Ce-III alloy exhibited superior linear attenuation coefficients and reduced half-value layer, reinforcing its effectiveness as a radiation shielding material. It can be concluded that Ce-III represents an optimal composition with a synergistic combination of structural stability, phase transformation control, and enhanced radiation shielding capabilities, making it a promising candidate for nuclear and high-radiation applications.
AtıfOpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Psychological effects of the COVID-19 pandemic on primary healthcare professionals in Turkey: One year into the pandemic
Yücel, Ummahan; Erkal Aksoy, Yasemin; Yaşar Yetişmiş, Habibe; Gök, Çiğdem
Aim and Objectives: This study aimed to determine the psychological effects of the COVID-19 pandemic on healthcare professionals working in primary care settings in the first year of the pandemic. Background: The healthcare industry has faced an unprecedented burden in the COVID-19 pandemic. Primary care professionals experienced the high level of psychological problems. Design and Methods: A total of 793 healthcare professionals from different regions of Turkey participated in this cross-sectional study. The STROBE (Strengthening the reporting of observational studies in epidemiology) checklist was used in the study. Data were collected online. Results: It has been found that more than half of healthcare professionals experienced severe depression, three-quarters experienced anxiety, and almost half experienced stress. It was also found that about half of the participants experienced a high degree of acute and chronic fatigue, and one-fifth experienced low inter-shift recovery. Conclusion: The effects of the COVID-19 pandemic on the mental health of primary care professionals, especially nurses and midwives, are alarming. The problems that arise from the flawed healthcare delivery models and gender inequality, which worsen the usual psychological effects of the pandemic on primary care professionals, should be addressed urgently. Relevance to Clinical Practice: Psychological support and rehabilitative services should be expanded to eliminate the short- and long-term psychological effects of the pandemic on healthcare professionals.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ2Response surface method (RSM) for optimization of electrical properties of polymer/CdS composites for dielectric capacitors
Torğut, Gülben; İncesu, Rabia
This paper aims to present the statistical evaluation of dielectric constant (έ) and conductivity (σ) performance of composites preparing Maleic Anhydride (MA) and Styrene (St) polymer with various amounts of Cadmium Sülfide (CdS) by analysis of variance (ANOVA) model. For this purpose, frequency, applied voltage and CdS amount at different weight percentages were selected as input factors while dielectric constant and conductivity of the composites were selected as the response. Analysis of input factors was performed, RSM method was designed and used for estimation of response factor. From the analysis results, we found that high values of dielectric constant and conductivity were strongly related to frequency and CdS amount. However, we found that applied voltage in the selected ranges did not have a significant effect on both factors. The structural properties of the composites were investigated by Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was investigated by Scanning Electron Microscopy (SEM). The presence of CdS in polymers has been proven by X-Ray Diffraction (XRD). The thermal properties of polymers were examined by thermogravimetric analysis (TGA).
AtıfScopus1WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ2Advancing Air Quality Monitoring: Deep Learning-Based CNN-RNN Hybrid Model for PM2.5 Forecasting
Utku, Anıl; Can, Umit; Alpsülün, Mustafa; Balıkçı, Hasan Celal; Amoozegar, Azadeh; Pilatin, Abdulmuttalip; Barut, Abdulkadir
Particulate matter, particularly PM2.5, poses a significant threat to public health due to its ability to disperse widely and its detrimental impact on the respiratory and circulatory systems upon inhalation. Consequently, it is imperative to maintain regular monitoring and assessment of particulate matter levels to anticipate air pollution events and promptly mitigate their adverse effects. However, predicting air quality is inherently complex, given the multitude of variables that influence it. Deep learning models, renowned for their ability to capture nonlinear relationships, offer a promising approach to address this challenge, with hybrid architectures demonstrating enhanced performance. This study aims to develop and evaluate a hybrid model integrating Convolutional Neural Networks (CNNs) and Recurrent Neural Networks (RNNs) for forecasting PM2.5 levels in India, Milan, and Frankfurt. A comparative analysis with established deep learning and machine learning techniques substantiates the superior predictive capabilities of the proposed CNN-RNN model. The findings underscore its potential as an effective tool for air quality prediction, with implications for informed decision-making and proactive intervention strategies to safeguard public health.
AtıfScopus10WoS6OpenAlex11İncele - MakaleYalnız künye2025Scopus SJRQ1Reduction of fluid forces on a circular cylinder in the laminar flow regime using a pair of airfoils
Fırat, Erhan; Oruç, Vedat; You, Rui; Biçer, Uğur; Devecioğlu, Atilla G.
Flow around the cylinder, with/without a pair of airfoils symmetrical to the cylinder's horizontal axis, was simulated for a diameter-based Reynolds number (Re) of 100. The objective of this numerical study is to simultaneously reduce the values of the time-averaged and fluctuating forces acting on a system consisting of a pair of airfoils and a cylinder below those of a single cylinder by using different combinations of the parameters chord (c), angle of rotation (β), angle of attack (α), and the shortest distance between the aerodynamic center of the airfoil and the surface of the cylinder (g). The values of these key parameters are determined primarily through two approaches. The first approach involves emulating the flow pattern surrounding the system to match the potential flow pattern. The second approach involves disrupting the interaction between the shear layers from the cylinder by stretching them in the mean flow direction. The second approach has been demonstrated to exhibit superior performance in terms of reducing both time-averaged and fluctuating forces concurrently. The second approach has been demonstrated to exhibit superior performance in terms of reducing both time-averaged and fluctuating forces concurrently. The optimal geometrical parameters that yield the desired end results are determined to be c = 0.5D, α = 0°, β = 60°, and g = 0.2D. Utilizing these parameters has been demonstrated to result in a substantial reduction in the time-averaged drag, fluctuating drag, and fluctuating lift coefficients of the system, with the respective percentage reductions reaching 14.4 %, 92.1 %, and 73 %, respectively, when compared to the values obtained for a single cylinder.
AtıfScopus4OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ2Multifunctional properties and microstructural correlations of NiCoMnTi-Based high entropy alloys with focus on magnetic, thermodynamic, and radiation shielding characteristics
Özkul, İskender; Karaduman, Oktay; Şimşek, Tuncay; Şimşek, Telem; Canbay, Canan Aksu; Güler, Ömer; ALMisned, Ghada; Baykal, Duygu Sen; Tekin, Huseyin Ozan
High-entropy alloys (HEAs) are a novel class of materials known for their complex compositions and exceptional multifunctional properties. In this study, NiCoMnTi-based HEAs were modified with Fe, Cr, and Cu as fifth elements to systematically investigate their structural, magnetic, thermodynamic, and nuclear radiation shielding characteristics. The alloys were synthesized via arc melting and characterized using XRD, SEM-EDS, VSM, and theoretical modeling methods. The findings reveal that each additional element uniquely alters the alloy’s properties. The Fe-containing alloy exhibited a well-defined lamellar microstructure, the highest saturation magnetization (10.79 emu/g), and a Curie temperature near 450 K, along with strong gamma-ray shielding performance across both low and high energy ranges. The Cr-containing alloy demonstrated soft magnetic behavior, featuring the lowest coercivity (29.64 Oe) and the highest fast neutron removal cross-section. In contrast, the Cu-containing alloy enhanced low-energy photon attenuation due to its higher atomic number but exhibited limited magnetic homogeneity. Despite these differences, all samples displayed stable thermodynamic behavior and comparable buildup factor trends. Overall, the addition of Fe led to a synergistic improvement in both magnetic and radiation shielding capabilities of the NiCoMnTi-based HEA system.
AtıfScopus3OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ3Cotton Fabric and Polypropylene Fabrics Treated with Synthesized Zinc Diborate
İpek, Yeliz; Ertekin, Özlem
Cotton fabrics and polypropylene fabrics are mostly used fabrics in many areas. Zn(B4O7) powder was synthesized with a sequential wet precipitation and sintering method. Focused ion beam scanning electron microscopy (FIB-SEM) figures and energy dispersive X-ray spectroscopy (EDS) mapping results showed that zinc diborate was highly and homogeneously adsorbed on the surface of the treated fabrics. When differential thermal analysis (DTA) results were examined, heat release seemed to decrease by 0.71 kJ g−1, 0.61 kJ g−1, and 0.46 kJ g−1for cotton fabric treated with zinc diborate (C-117-ZB), polypropylene fabric (20 g m−2) treated with zinc diborate (PP-20-ZB), and polypropylene fabric (65 g m−2) treated with zinc diborate (PP-65-ZB), respectively. According to vertical burning test, burning rates of cotton fabric (C‒117), C‒117‒ZB, polypropylene fabric (PP‒65), PP‒65‒ZB, polypropylene fabric (PP‒20), and PP‒20‒ZB were calculated as 3.25 cm s−1, 1.93 cm s−1, 0.75 cm s−1, 0.36 cm s−1, 0.88 cm s−1, and 0.71 cm s−1, respectively. Heat releases and burning rate decreases were in good agreement for all treated fabrics. Also breaking strengths of both fabric types were improved. The washing test exhibited that the amount of zinc diborate powder on the cotton fabric sample was released by 25.49% while PP-65-ZB and PP-20-ZB fabrics released about 90% by weight of adsorbed powder. Although improvement was observed in the fire resistance of PP fabrics, antibacterial activity against Escherichia coli and Staphylococcus aureus could not be achieved. However, antibacterial activity was provided only for the cotton fabric.
- MakaleYalnız künye2025Scopus SJRQ2The Discursive Foundations of Chinese Foreign Policy under Xi Jinping: A Non-Western Theoretical Analysis
Gökcan, Özkan
China’s economic rise in the 21st century has prompted analyses of how this ascent will be reflected in the political sphere. Analyses in West-ern-centric media outlets and academia have predominantly focused on the notion that China will seek hegemony and an alternative international order in parallel with its economic rise. The central claim of this study is that these analyses, primarily based on realist and liberal assumptions, are incompatible with Xi Jinping’s foreign policy discourse. Therefore, Chinese foreign policy should be analyzed from an alternative theoretical perspec-tive. Building on this claim, this study first analyses the general framework of the discourse on which Chinese foreign policy was built during the Xi Jinping era. Subsequently, this discourse is examined in Tianxia, a Chi-na-centered non-Western theory. This analysis, supported by examples of concrete foreign policy steps in the concluding section of the study, aims to provide a non-Western perspective on Chinese foreign policy.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2025Scopus SJRQ1Selection of the central composting facility for organic wastes through the Bayesian best worst method and Geographic information system incorporation: The case of Istanbul
Güler, Mustafa; Samastı, Mesut; Yücesan, Melih; Gül, Muhammet; Çelik, Erkan; Ciner, Miraç Nur; Algorabi, Ömer
The rapid increase in municipal solid waste (MSW) generation, driven by population growth and unplanned urbanization, has made the location of organic waste collection and disposal facilities a critical issue for metropolitan cities. Improper waste management practices threaten environmental sustainability, human health, and urban futures. This study applies multicriteria decision-making (MCDM) methods to identify the optimal placement for a central composting facility in Istanbul. A novel MCDM mechanism was developed, building on existing methods and addressing a gap in the literature. While determining the criteria, academic studies on this subject were researched in depth and the criteria used in these studies were brought together to obtain 28 criteria. The study assessed 28 criteria using the Bayesian Best-Worst Method (BWM) to determine their relative importance. These weights were then integrated into a Geographic Information System (GIS) to produce a suitability map, highlighting the most appropriate locations for the facility. Based on this analysis, the Çatalca Karacabey region was identified as the optimal site, ensuring reduced environmental impact and improved efficiency in organic waste management. The study contributes both theoretically and practically to the field, offering a robust framework for sustainable waste facility siting and providing actionable insights for urban governance. The study provides valuable insights for facility siting and urban governance, while highlighting areas for future research.
AtıfScopus5WoS4İncele - MakaleYalnız künye2025Scopus SJRQ1Seasonally adjusted periodic time series for Mann-Kendall trend test
Güçlü, Yavuz Selim; Acar, Ramazan; Saplıoğlu, Kemal
In this study, temperature data trend analysis is conducted, which is thought to be influenced by global warming, climate change, and local factor impacts. The main objective of this paper is to obtain an acceptable autoregressive correlation value for the MK test. For this purpose, seasonality (periodicity) especially in monthly time series is adjusted. Autoregressive correlation and homogeneity test values decrease after seasonal adjusting, but reasonable results are not achieved. Then, prewhitening procedure is also applied to the seasonally adjusted data. This process resulted in the data becoming both homogeneous and free autoregressive correlation. The final version of the time series is suitable for the MK test. Furthermore, the time series are divided into different time intervals, and the efficacy of the method is investigated. The results demonstrated that the method is suitable for time series with less than 30 years of data. The study demonstrated that the proposed method enhances the reliability of the data. Also, multiplication by 12 (months) allows the MK test with Z score in place of the Student's t-test in short-term data sets. This suggested methodology can be used to identify MK trend conditions in monthly time series. The application is based on monthly and annual average temperature data between 1957 and 2022 from three stations within the Kızılırmak basin (Çankırı, Kırşehir, Sivas stations) and one station within Seyhan Basin (Adana station) in Türkiye. The test results exhibited a significant increasing trend.
AtıfScopus37WoS34OpenAlex41İncele - MakaleAçık Erişim2025Scopus SJRQ2Comprehensive evaluation of thermal, structural, magnetic, and radiation shielding properties of CuAlNi and CuAlNi-X (X = Co, CoFe, CoFeMn, CoFeMnCr) high-temperature shape memory alloys
Özkul, İskender; Karaduman, Oktay; Şimşek, Telem; Şimşek, Tuncay; Canbay, Canan Aksu; Güler, Ömer; Şan, Mert Hüseyin; ALMisned, Ghada; Tekin, H.O.
This study investigates the thermal, structural, magnetic, and radiation shielding properties of CuAlNi-based high-temperature shape memory alloys (HTSMAs) enhanced through sequential alloying with Co, Fe, Mn, and Cr. Five different variants were produced, designated as CRef (reference CuAlNi alloy), CCo (CuAlNiCo), CFe (CuAlNiCoFe), CMn (CuAlNiCoFeMn), and CCr (CuAlNiCoFeMnCr). Differential scanning calorimetry (DSC) confirmed the presence of reversible martensitic transformations in all alloys, with Co and Mn additions significantly enhancing thermal stability. Structural analyses using X-ray diffraction (XRD) and microscopy showed significant grain refinement and phase transitions, while magnetic measurements highlighted the strong ferromagnetic response of CCo (CuAlNiCo) and the increased coercivity of CMn (CuAlNiCoFeMn) due to domain-pinning effects. Moreover, radiation shielding analyses demonstrated the critical influence of density and elemental composition, with CRef exhibiting superior linear attenuation coefficients (LAC), effective atomic number (Zeff), and energy absorption buildup factor (EBF) performance, attributed to its optimized Cu fraction and high density (7.1296 g/cm3). In contrast, CMn (CuAlNiCoFeMn) showed the weakest shielding properties due to reduced density and Mn content. Among the samples, CRef emerged as the superior alloy, demonstrating exceptional multifunctionality across all evaluated parameters, while CCr (CuAlNiCoFeMnCr) displayed synergistic properties, combining shape memory behavior with competitive shielding efficiency. It can be concluded that CuAlNi-based HTSMAs hold significant potential as multifunctional materials, particularly for nuclear safety and aerospace engineering applications, where adaptive functionality and radiation protection are critical.
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