Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(24)
- Cuce, Erdem(18)
- İspirli, Hümeyra(14)
- Cuce, Pinar Mert(13)
- Alım, Bünyamin(12)
- Mercan, Emin(12)
- Sert, Durmuş(12)
- Şenay, Volkan(12)
- Tozlu, Alperen(11)
- Artar, Musa(10)
- Korkmaz, Şadan(10)
- Pat, Suat(10)
- Yilmaz, Mustafa Tahsin(10)
- Özen, Soner(10)
- Gökçe, H.S.(9)
- Sagdic, Osman(9)
- Şakar, Erdem(9)
- Bayram, Ozkan(8)
- Demirtas, M.(8)
- Purcek, G.(8)
- Ergün, Mustafa(7)
- Yanar, H.(7)
- Demir, Lütfü(6)
- Taylan, Osman(6)
- Abdioglu, M.(5)
- Abdioglu, Murat(5)
- Alim, Bünyamin(5)
- Carbas, Serdar(5)
- Guclu, Tamer(5)
- Gökçe, H. Süleyman(5)
- Sayyed, M.I.(5)
- Han, İbrahim(4)
- Ozturk, K.(4)
- Zhang, Z.F.(4)
- Zhang, Z.J.(4)
- Özahi, Emrah(4)
- Şahin, Engin(4)
- Abusoglu, Aysegul(3)
- Andiç-Çakır, Özge(3)
- Baltakesmez, Ali(3)
Yayınlar
- MakaleAçık Erişim2025Scopus SJRQ1Experimental and numerical investigation of flux trapping in bulk YBCO under different permanent magnet configurations
Uzun, Oguzhan; Abdioglu, Murat; Ozturk, U. Kemal
This study investigates flux trapping in bulk YBaCuOx (YBCO) high-temperature superconductors (HTS) under various permanent magnet configurations (PMCs) through both experimental and numerical methods. A finite element method (FEM) based on the H-formulation of Maxwell's equations is employed to simulate the HTS-PM interaction, showing good agreement with experimental results in peak trapped flux density values. The maximum trapped flux densities for PMC-1, PMC-2, PMC-3, and PMC-4 were measured as 207 mT, 359 mT, 392 mT, and 478 mT, respectively, demonstrating the significance of PMC design in optimising flux trapping in HTS materials. Enhanced flux trapping was observed with configurations including additional permanent magnets, such as PMC-2 and PMC-4, yielding trapped flux efficiencies of 77.5 % and 55.0 %, respectively. Obtained results in trapped flux efficiency are very impressive as compared to a value of 23 % trapped flux efficiency in literature in which a solenoid magnet with a 3 T peak value of magnetic flux density is used to trap a magnetic field in the HTS. The magnetic flux trapping methodology of this research is very effective for magnetic bearing applications with self-stabilisation in which high magnetic fields are not needed since it doesn't need any magnetic field sources with complex structures, such as coils, to facilitate the magnetic field trapping in the HTSs.
AtıfScopus3WoS3OpenAlex2
İncele - MakaleAçık Erişim2025Scopus SJRQ1Joule heating of carbon fiber in hybrid composites with glass fibers: Investigation of electro-thermal and vibration characteristics
Uslu, Emin; Yilmaz, Galip; Uyar, Mehmet
This study explores the innovative dual-purpose use of carbon fiber, functioning both as a structural and a heating element, expanding its potential in hybrid composites. A prototype composite was fabricated using the vacuum infusion process, featuring a single carbon fiber layer at the core for dual-purpose and two outer layers of glass fiber. Electrical heating tests revealed a stable relationship between voltage, resistance, power, and temperature, demonstrating efficient heat generation as the voltage increased. Thermal imaging confirmed uniform heat distribution with minor variations. Free vibration tests evaluated the composite's dynamic behavior under various electro-thermal conditions. Results showed that increasing temperature reduced the natural frequencies, particularly in the second vibration mode. Changes in Rayleigh damping coefficients at higher temperatures highlighted the composite's sensitivity to thermal inputs. These findings underline the potential of hybrid composites for advanced applications like turbine blades and aerospace components, where multifunctionality, self-heating, and vibration control are critical.
- MakaleYalnız künye2025Scopus SJRQ1Eco-friendly reduction of graphene oxide using urea: An optimized approach for high-performance rGO
Ucuncuoglu, Didar; Bektaş, Enes; Karakaş, İbrahim Hakkı; Amin Bhuiyan, Mohammad Ruhul; Korucu, Haluk
The growing demand for environmentally friendly and cost-effective approaches has accelerated the development of sustainable methods for the synthesis of reduced graphene oxide (rGO). In this study, urea was utilized as a green reducing agent for rGO synthesis, offering an alternative to conventional toxic chemicals. The synthesized rGO was comprehensively characterized using FTIR, SEM-EDS, Raman spectroscopy, XRD, BET analysis, zeta potential, and conductivity measurements. These analyses revealed key functional, structural, and morphological properties, including surface functional groups, elemental composition, carbon-to-oxygen (C/O) ratio, particle size (PS), crystallite size (CS), specific surface area (SSA), zeta potential (ZP), thermal conductivity (TC), and electrical conductivity (EC). Process optimization was performed using the Taguchi L4(23) orthogonal array design across nine quality parameters. Under optimal conditions, notable enhancements were achieved: C/O ratio increased by 108%, ID/IG ratio by 164%, I2D/IG ratio by 26%, CS by 75%, and SSA by 134%, while PS was reduced by 37%. Furthermore, ZP and TC increased by 58% and 33%, respectively, whereas EC was reduced by 97%. These findings demonstrate the potential of urea as a sustainable and effective reducing agent in the production of high-performance rGO materials.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1The impact of osmotic dehydration and microwave drying process conditions on the quality characteristics of celery roots (Apium graveolens l. Subsp. rapaceum)
Kutlu, Naciye
In this study, celery roots were dried by the osmotic dehydration-assisted microwave drying method, and both osmotic dehydration (OD) and microwave conditions were optimized using response surface methodology (RSM). Utilizing a Box–Behnken experimental design, the drying time was minimized while maximizing the total phenolic compounds (TPC) in dried samples at different OD salt concentrations (10, 20 and 30 %), OD temperatures (30, 45 and 60 °C), OD durations (1, 2 and 3 h) and microwave powers (210, 350 and 490 W). The optimal drying conditions were identified as 15.05 % for OD salt concentration, 42.5 °C for OD temperature, 1.6 h for OD duration and 489.7 W for microwave power. Under these optimal conditions, the predicted values for time and TPC were 10 min and 104.38 mg GAE/100 g, respectively. The composite desirability value was 0.99 as a result of optimization. The experimental values for time and TPC were measured as 11 min and 97.45 mg GAE/100 g, respectively. The predicted and experimental values were found to be statistically similar to each other. A comparison with control groups designed to assess the effects of OD and microwave processes revealed that these processes significantly influenced both quality (TPC, antioxidant activity, color) and drying characteristics (drying time, rehydration rate). The greenness assessment value was calculated as 78 using the MoGAPI tool. Consequently, the application of OD pretreatment and use of the innovative microwave drying method as a final drying step in vegetable drying was successfully implemented to enhance the properties of the final product.
AtıfScopus3WoS3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ1Multi-input hybrid face presentation attack detection method based on simplified Xception and channel attention mechanism
Günay Yılmaz, Asuman; Turhal, Uğur; Nabiyev, Vasif
Currently, biometric recognition systems, especially facial recognition systems, are frequently used for person authentication. Increasing facial image and video sharing on social media makes these systems vulnerable to attacks. For this reason, there is an increasing need for sensitive face presentation attack (FPA) detection systems. In this paper, a lightweight multi-input hybrid deep convolutional neural network model was proposed for FPA detection. For this purpose, a simplified version of the widely used Xception network was developed. This model was extended via squeeze and excitation blocks to weight the data in the feature encoding channels. In addition, a simple residual network architecture with attention blocks was designed. The FPA detection performances of these models were subsequently examined in cases where the input data consisted of the raw images or cropped facial images. According to the results, a deep learning architecture with three parallel connections was proposed. The raw images, cropped facial images, and face-weighted multi-color multi-level local binary pattern features were given as inputs to the proposed model. Therefore, a multi-input hybrid FPA detection model was created using both hand-crafted features and deep features. The proposed architecture has approximately 82% fewer parameters than the original Xception network does. The experimental results on the benchmark CASIA and REPLAY-ATTACK datasets demonstrate the model's effectiveness, achieving a 1.53% equal error rate (EER) on the CASIA dataset and 0.00% EER with a 0.07% half total error rate (HTER) on the REPLAY-ATTACK dataset. These results outperform many state-of-the-art methods while requiring significantly fewer computational resources, making the approach suitable for deployment in resource-constrained environments.
AtıfScopus5WoS4OpenAlex2İncele - Derleme MakaleAçık Erişim2025Scopus SJRQ1Effects of plant-derived antioxidants to the oxidative stability of edible oils under thermal and storage conditions: Benefits, challenges and sustainable solutions
Yildiz, Aysun Yurdunuseven; Öztekin, Sebahat; Anaya, Katya
The stability of edible oils significantly influences their quality, safety, and shelf life. While synthetic antioxidants have traditionally been used, the growing consumer interest in food safety and sustainability has shifted focus towards natural alternatives. Plant-derived antioxidants offer a promising solution, enhancing oxidative stability while meeting clean-label demands. This review examines recent advancements in using plant-derived antioxidants, such as extracts, essential oils, and agro-industrial by-products, to inhibit lipid peroxidation and improve edible oils' oxidative and thermal stability. Natural antioxidants from peels, seeds, spices, fruits, and vegetables effectively reduce hydrolysis, polymerization, and secondary oxidation products. Despite their potential, challenges remain, including impacts on sensory attributes, regulatory compliance, and the need for standardized extraction and application protocols. Addressing these limitations can advance sustainable food preservation and encourage the integration of natural antioxidants in the food industry, contributing to a more sustainable economy and shelf life.
AtıfScopus51WoS51
İncele - MakaleYalnız künye2025Scopus SJRQ1Optimized model updating and site-specific seismic assessment of a historical masonry bridge
Tayfur, Bilal
This study comprehensively evaluates an 800-year-old masonry bridge using advanced non-destructive testing techniques, an innovative model update process, and site-specific ground motion analysis. Employing Operational Modal Analysis, Ultrasonic Pulse Velocity, and Schmidt Hammer tests, the research meticulously characterized the structural dynamic properties. The preliminary finite element model was rigorously refined utilizing the Tabu Search optimization algorithm by minimizing discrepancies between numerical and experimental modal parameters. Site-specific earthquake records, carefully selected and prepared in accordance with the Turkish Building Earthquake Code, were applied to conduct detailed time-history analyses across 11 distinct ground motion records. Despite experiencing stresses approaching critical thresholds, the bridge demonstrated remarkable structural integrity. While the findings indicate the bridge’s structural soundness under current seismic hazard analysis criteria, the results notably emphasize that the frequency content similarities between the structure and ground motion are more critical for seismic performance assessment than peak ground acceleration (PGA) values, underscoring the importance of continuous monitoring given the region’s complex tectonic characteristics.
AtıfScopus5WoS3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ1Evaluation of the optical, structural, and morphological characteristics of a Sn-doped α-Fe2O3 thin film fabricated using RF and DC magnetron Co-sputtering technique
Salari, Maryam Abdolahpour; Şenay, Volkan; Muğlu, Günay Merhan; Sarıtaş, Sevda; Kundakçı, Mutlu
In this research, a Sn-doped hematite (α-Fe2O3) thin film on a glass substrate was synthesized using DC and RF magnetron sputtering techniques, and the physical features of the film were analyzed in detail. This study, conducted to investigate the effects of Sn doping on the hematite structure, evaluated the optical and morphological attributes of the thin film using advanced characterization techniques such as UV–VIS spectroscopy, Raman spectroscopy, XRD, SEM, EDS, and AFM. The optical band gap was determined from absorption measurement and calculated to be 2.12 eV. Raman spectroscopy results revealed various characteristic peaks between 100 cm−1 and 1500 cm−1. A strong (214) diffraction peak confirms the enhanced hematite phase formation in the thin film. The crystallite size of the Sn-doped thin film, calculated via Scherrer's formula, is 20 nm. SEM images showed that the thin film exhibited a smooth and homogeneous surface morphology on the glass substrate. According to the EDS results, the atomic doping ratio of Sn in Fe2O3 is 2.84 %. Additionally, AFM analysis confirmed that the Sn-doped α-Fe2O3 thin film had a smooth surface, as indicated by a low RMS (Root Mean Square) roughness value of 8.11 nm. These properties suggest that the thin film could be suitable for optoelectronic applications. The study emphasizes the potential of Sn-doped α-Fe2O3 thin films, particularly for optoelectronic and photocatalytic devices, and underscores the need for further investigation of these materials. Furthermore, it was concluded that these materials should be considered in a broader context for their potential use in various technological applications.
AtıfScopus23WoS22OpenAlex25İncele - MakaleYalnız künye2025Scopus SJRQ3Inorganic CNTS as a potential hole-transport material for extremely stable and effective perovskite solar cells
Sari, Fahriye; Ozel, Sultan Suleyman; Ozel, Faruk; Bersani, Massimo; Kus, Mahmut
In view of these distinctive properties, chalcogenide materials have attracted attention in response to the growing need for sustainable energy sources, with a particular focus on the efficient utilization of solar energy. One of the principal challenges associated with PSCslies in addressing the fill factor (FF) deficit and resolving stability concerns. Band alignment and resistance at the interface further reduce the fill factor, thereby limiting device performance. This research demonstrates that Cu2NiSnS4 (CNTS) can serve as an effective hole transport material for perovskite solar cells, offering an enhanced stability. In this study, kesterite-based CNTS is utilized as a hole-selective interlayer in inverted CH3NH3PbI3 perovskite solar cells (PSCs) on ITO/CNTS substrates. CNTS was selected due to its numerous advantages, including the abundance of their constituent elements in nature, non-toxicity, cost-effectiveness, appropriate band gap and absorption coefficient for photovoltaic (PV) applications, as well as their tunable band gap properties. Deposition of CNTS onto ITO glass alters the substrate's work function, resulting in open-circuit voltages exceeding 1.0 V. Solar cells on ITO substrates without a metal oxide layer demonstrated an exceptional power conversion efficiency (PCE) of 10.6 %. This highlights the potential of PSCs for high performance with a single selective contact. Our findings reveal that these cells retain over 93 % of their initial efficiency after 720 h, demonstrating improved stability. Replacing p-type organic materials with inorganic counterparts offers a promising avenue for further research.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1Comparative quality assessment of plant-based kefir as a vegan alternative to traditional kefir
Meral-Aktaș, Hacer; Bazu-Çırpıcı, Burcu; Aktaș, Haktan; Kadi̇roğlu, Hafsa; Çeti̇n, Bülent
Plant-based milk is emerging as a promising alternative for vegan and vegetarian diets and for people who are allergic to animal products. In this study, kefir was produced using hazelnut, walnut, and cashew milk, and fermented with a combination of Bifidobacterium longum (human origin) and selected autochthonous microbial strains with probiotic potential found in traditional kefir. Significant variation was identified in the physicochemical, microbiological and sensory analyses of kefir produced with plant-based milk and cow milk kefir as a control. In particular, phenolic compound and total phenolic contents were found to be greater in plant-based kefir than in cow milk kefir. Notably, walnut kefir exhibited the highest total phenolic content at 843 mg GAE/L, compared to 83 mg GAE/L in cow milk kefir, highlighting a significant increase in antioxidant potential. On the other hand, the sensory properties of cow milk kefir were rated higher than those of kefir made with plant-based milk. These findings suggest that plant-based kefir can serve as a vegan beverage alternative, although further development is needed to improve flavour acceptability.
AtıfScopus5WoS5OpenAlex8İncele - MakaleAçık Erişim2025Scopus SJRQ3The performance of Ag2S/X (X: Co and Ni) nanocrystals as counter electrodes in dye-sensitized solar cells
Ozel, Sultan Suleyman; Bulucu, Esen Dagasan; Sarilmaz, Adem; Ozel, Faruk
In the present study, Silver sulfide (Ag2S)-based nanocrystals (NCs) were synthesized by employing a facile hot injection method. These NCs are utilized as counter electrodes on dye-sensitized solar cells (DSSCs), representing a smart approach that utilizes these NCs as catalysts instead of platinum (Pt) for the first time. The study provides a comparative analysis of the performance of Ag2S-based counter electrodes (CEs) in DSSCs technologies the traditionally compared Pt-based electrodes under identical conditions. The findings showed that the Ag2S-based DSSCs exhibited a power conversion efficiency (ƞ) that was approximately 5.2 % higher than that of the platinum-based DSSCs. Consequently, the results of this study demonstrate that Ag2S-based NCs possess the potential to function as novel counter electrode materials for low-cost, Pt-free solar cells. Moreover, the results of this study bear considerable implications for the development of cost-effective and sustainable solar energy solutions. The advent of Ag2S-based NCs signifies a significant milestone in the quest for sustainable and efficient energy solutions. This study also invites further exploration into other potential material combinations and synthesis methods that could enhance the properties and performance of DSSCs.
AtıfScopus4WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1The prebiotic potential of alternansucrase-based glucooligosaccharides: the effects on short-chain fatty acids production and microbiome diversity
Ozulku, Gorkem; Harris, Hannah C.; Savva, George M.; Ahn-Jarvis, Jennifer H.; İspirli, Hümeyra; Dertli, Enes; Warren, Frederick J.
Glucooligosaccharides (GLOS) produced by glucansucrases via acceptor reactions are oligosaccharides that transit upper intestinal tract and evade digestion and may be considered to be a prebiotic. The prebiotic function of GLOS can be dictated by the type of acceptor sugar used during its production. Therefore, the prebiotic effect on the gut microbiome and short chain fatty acids (SCFAs) production can be used to inform the selection of acceptor sugars. In this study, alternansucrase-based GLOS derived from different acceptor sugars (melibiose, cellobiose and lactose) and inulin (positive control) were investigated using in vitro colon model fermentation to examine their prebiotic effect and SCFAs production. Microbiome composition was determined using shotgun metagenomics. SCFAs and lactate formation was determined using 1H NMR spectroscopy. Fusicatenibacter saccharivorans and Bacteroides uniformis appeared to increase in abundance after 24 h following fermentation of all three GLOS. The highest abundance for Bifidobacterium longum was seen after supplementation with lactose derived GLOS. Fermentation of GLOS appeared to produce around twice as much acetate than fermentation with inulin, while similar amounts of other SCFAs and lactate were produced. Melibiose derived GLOS supplementation in healthy 3 donors increased F. saccharivorans while inulin supplementation promoted Lactobacillales in order level. This study suggests that there may be beneficial effects of GLOS's on gut microbiome composition and metabolite composition, relative to the effects seen for inulin.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Sensitive and selective nitrite sensor based on CuCo2O4-rGO nanocomposite synthesized by one-pot electrochemical method in pastırma
Anlar Daldal, Pınar; Öztürk Doğan, Hülya; Cinar Topcu, Kübra
In this study, CuCo₂O₄-rGO nanostructures were synthesized by a one-pot electrochemical method on the surface of Pencil Graphite Electrode (PGE) for nitrite determination in pastırma, a traditional meat product. The developed modified electrode was used to determine the amount of nitrite in pastırma samples obtained from three different brands in the Turkish market. When the nitrite values obtained by the electrochemical method were compared with the spectrophotometric method, they showed 91.20 % to 100 % agreement. In addition, the physicochemical properties of pastırma samples, such as pH, moisture, protein, fat, and ash, were analysed, and it was determined that pH and moisture values are critical parameters for product quality. These results show that the developed electrode provides a practical and sensitive method for nitrite sensing.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Experimental performance assessment of two-stage thermoelectric system in a closed-cycle drying process
Osta, Muhammet Harun; Yakut, Kenan; Köksal, Hüseyin
Traditional drying systems suffer from several limitations, including high energy consumption, insufficient hygienic control, and the inability to maintain precise temperature regulation. Although alternative drying systems have been developed to address these issues, they often encounter practical challenges due to their complex structures and the need for numerous external components. To overcome these limitations, this study proposes and experimentally evaluates a novel, independently operating, two-stage thermoelectric module (TEM) system integrated into a closed-loop drying setup that eliminates the need for external heating and dehumidification components. The proposed system addresses the efficiency and hygiene problems observed in conventional dryers by simultaneously performing air heating, cooling, and dehumidification functions through compact thermoelectric devices. The drying process consists of two stages: the first involves air pre-conditioning (heating/cooling), while the second is dedicated to dehumidification. The performance of the system has been evaluated based on key metrics such as cooling and heating capacities, the coefficients of performance (COP) for both stages, moisture removal rate (MRR), and moisture removal rate effectiveness (EffMRR). Experimental studies were conducted under input voltages ranging from 3 to 7 V, relative humidity levels between 60 % and 90 %, and varying airflow rates. Under 90 % relative humidity conditions and a 7 V input voltage, the system achieved a maximum moisture removal rate of 13.1 g/h. The first-stage TEM reached a heating capacity of 68.81 W and a cooling capacity of 26.34 W, while the second stage provided 21.17 W of cooling capacity.
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ1Optimum steel frame design through ultimate seismic energy dissipation of double diagonal friction dampers
Carbas, Serdar; Artar, Musa
In this paper, a creative design methodology is exhibited to attain seismic design optimization of steel frames that are equipped with double diagonal braces on which Pall friction dampers (PFDs) are mounted. The PFDs supply highest seismic energy dissipation to a structure for restricting destructive structural responds. Hence, the PFDs provide elastic movement to the steel frames to avoid the damaging consequence of an earthquake. To achieve this, the seismic energy dissipation over PFDs mounted on double diagonal brace members are tried to be maximized in this study. The Kobe earthquake record is used for conducting nonlinear dynamic time-history analyses to acquire structural responses of the steel frames. The Jaya algorithm (JA) that is a gradient- and parameter-free metaheuristic optimization technique is selected as an optimizer. The design algorithm encoded in MATLAB is integrated with SAP2000 structural analysis program through inbuilt open application programming interface (OAPI) functions to achieve simultaneous structural seismic responses. In proposed design methodology, firstly the optimal designs of steel frame structures without implementing double diagonal friction dampers are accomplished under effect of seismic loading exposed to structural design constraints of stress, displacement, drift, and geometric taken from AISC-ASD structural specifications. Then, the double diagonal friction dampers are implemented in the optimally sized frames to determine optimum yield strengths which are frictional slip loads. Hereby, the JA makes certain the dissipated seismic energy as maximum by checking the yield strength between the frame stories. In the end, it is verified that the PFD mounted double diagonal friction dampers provide maximum seismic energy dissipation throughout the steel frame structures for optimal sizing.
AtıfScopus8WoS7OpenAlex5İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ1Enhanced thermal and angular velocity-induced hybrid piezoelectric energy harvesting of smart turbine blades
Uyar, Mehmet
In this study, an approach is proposed to examine hybrid piezoelectric energy harvesting performances from vibrations induced by thermal and angular velocity loads in order to generate energy from the smart turbine blade. In the proposed method, a smart turbine blade is formed by patching the piezoelectric material to the root surface of the turbine blade. A finite element (FE) model of the smart turbine blade is established and then it is validated with a smart blade model in a reference study to test the reliability and accuracy of the FE method. The defined loads are applied to the smart blade to obtain energy from mechanical vibrations induced by thermal and angular velocity loads. Temperature distribution, voltage, and vibration results obtained from energy harvesting analysis under different thermal and angular velocity loads are presented. In order to investigate the energy conversion efficiency of the energy obtained from the system, the energy harvesting circuit is tested in terms of battery discharge times and power output values. The results show that while the maximum energy conversion in the thermally induced smart turbine blade is 11.9 W, a power output of 12.3 W is obtained from the hybrid energy harvesting mechanism under angular velocity and heat flux loads.
AtıfScopus5WoS5OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ1District heating based on exhaust gas produced from end-of-life tires in Erzincan: Thermoeconomic analysis and optimization
Güngör, Osman; Tozlu, Alperen; Arslantürk, Cihat; Özahi, Emrah
This paper presents the thermoeconomic analysis and optimization of the Erzincan Waste Tire Recycling and Power Plant (EWTRPP) in Turkey and its waste heat-based district heating (DH) system. A thermoeconomical method, namely the specific exergy costing (SPECO), is applied to allocate cost flows through subcomponents of an actual existing plant. Besides, the obtained thermoeconomic results are improved by using an optimization method, namely non-dominant sorting genetic algorithm (NSGA-II), considering the temperature of the exhaust gas discharged to the atmosphere (T25), the thermal conductivity value of the insulation material (ki) and pipe roughness value (s). The energy and exergy efficiencies of the existing plant are found to be 27.37% and 35.57%, respectively, considering the data of the actual plant. Moreover, the energy and exergy efficiencies of the waste heat-based DH system are found to be 43.08% and 55.99%, respectively. The total cost rate of the overall system is deduced 13.98 $/hby means of SPECO method. According to the results of the NSGA-II optimization method, the exergy efficiency and total cost rate of the overall system are evaluated as 6.93% and −2.51 $/h, respectively. Furthermore, it is also proposed that 1304 dwellings can be heated owing to the DH system utilizing the existing exhaust gas.
AtıfScopus9WoS8OpenAlex7İncele - MakaleYalnız künye2024Scopus SJRQ1Effect of oxidation on radiation shielding capacity of ZrNbTaMoW Refractory High Entropy Alloys (RHEA) for nuclear reactor applications: Experimental and theoretical assessment
Sakar, E.; Guler, O.; Alim, B.; Guler, S.H.; Dikici, B.; Lampke, T.
This study presents the production and comprehensive assessment of a Refractory High Entropy Alloy (RHEA) with a ZrNbTaMoW composition for possible usage nuclear reactor applications. The alloy was synthesized using the mechanical alloying (MA) method, and its radiation properties were examined. Elemental powders of Zr, Nb, Ta, Mo, and W were utilized in equimolar quantities during the 120-hour MA process, conducted under a high-purity Ar atmosphere to prevent oxidation. The obtained HEA was then subjected to a mechano-thermal process to transform it into Refractory High-Entropy Oxide (RHEO) for comparing their radiation-shielding performance under oxide conditions. The characterization of the produced alloys through X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron dispersive spectroscopy (EDS). The photon shielding parameters of the alloys were experimentally obtained for various energies emitted from a 133Ba radioactive source, employing a Canberra UltraLEGe semiconductor detector. Furthermore, theoretical calculations were performed to validate the experimental data and to evaluate the alloys' photon shielding capabilities comprehensively. For this purpose, Phy-X/PSD software was employed to determine mass attenuation coefficients, half-value layer, effective atomic number, and effective electron density. Fast neutron absorption capabilities were determined through the calculation of average absorption cross-sections in the 2–12 MeV energy range. The results showed that the oxidation process significantly diminished the photon absorption capacity of RHEA.
AtıfScopus34WoS33OpenAlex37İncele - MakaleAçık Erişim2024Scopus SJRQ1Investigation of temperature effect on the optimal weight design of steel truss bridges using Cuckoo Search Algorithm
Keleş, Meryem; Artar, Musa; Ergün, Mustafa
In this article, the optimum weight design of steel truss bridges is carried out by considering the effect of temperature. One of the most significant issues such structures may encounter throughout their service life is the extreme temperature changes that can occur for various reasons. If a steel bridge is designed without considering this unfavorable scenario that might arise in the future, significant damage could happen in terms of the usability limit state, and it might even collapse by exceeding its carrying capacity before reaching its service life. Therefore, this study aims to conduct weight optimizations of steel truss bridges, considering the effect of temperature. Thus, it has been revealed how high-temperature variations alter material properties and affect the overall optimum weight of the structure. For this purpose, the minimum-weight designs of three planar steel truss bridges previously analyzed by other researchers have been re-evaluated using the Cuckoo Search Algorithm. The main program containing the flow steps of the algorithm based on the finite element method is coded in MATLAB. Stress and displacement limit values are used as constraints in solving the problems. The optimum weight results for each structure in the case of temperature effect not being considered are relatively similar. Thus, it has been demonstrated that the Cuckoo Search Algorithm can optimize such problems by comparing its results with similar studies in the literature. Then, the analyses are renewed by incorporating the temperature effect using this proven method. When the findings of both cases are examined, it is observed that the optimum weight values for all structures under the influence of temperature increase. This is due to the decrease in the material's modulus of elasticity because of the high-temperature change. In this case, the cross-section is insufficient owing to the loss of rigidity, and larger profiles are needed. The structure's weight tends to increase depending on the severity of the temperature. Also, numerical simulations of the structures under the same conditions are carried out with SAP2000 software to supplement the design optimization analyses detailed above and enrich the research content.
AtıfScopus16WoS13OpenAlex11İncele - MakaleYalnız künye2024Scopus SJRQ2The wound healing effect and DNA damage repair of exopolysaccharide extracted from Weissella cibaria MED17
Kahraman-Ilıkkan, Özge; Akad Dinçer, Selin; Bağdat, Elif Şeyma; Çağlar, Işılsu; Dertli, Enes; İspirli, Hümeyra; Şahin, Feride İffet
Lactic acid bacteria can synthesize exopolysaccharides (EPSs), and some of these EPSs have pharmaceutical or medicinal properties. However, the wound healing capacities of EPSs have rarely been reported. In this study, EPS extracted from Weissella cibaria MED17 was used to investigate wound healing capacity. MED17 EPS was previously characterized and antioxidant capacity was also demonstrated. The application dose of the compound was determined by the MTT assay. The comet assay was applied to reveal the free radical scavenging activity and protection capacity of MED 17 against DNA damage by inducing oxidative stress and DNA damage with Mitomycin-C (MMC) in the cells. The comet assay showed that 15 mg/ml MED 17 EPS could ameliorate DNA damage by 50%. Moreover, the scratch test investigated the wound-healing effect of MED 17 EPS on HT-29 colon cells. MED 17 EPS could stimulate the migration of HT-29 and ameliorate MMC-induced DNA damage. However, further studies need to be conducted to clarify the mechanisms of the wound-healing process of MED 17.
AtıfScopus5WoS5OpenAlex5İncele