Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Çolak, Murat(8)
- Bayram, Sinan(5)
- Öner, Erdal(5)
- Can, Zehra(4)
- Ecem Bayram, Nesrin(4)
- Kolaylı, Sevgi(4)
- Turan, Muhittin(4)
- Demirtaş, Betül(3)
- Dispinar, Derya(3)
- Erbayrak, Engin(3)
- Gumus, Beril Eker(3)
- Kamiloğlu, Aybike(3)
- Türker, Temel(3)
- Yanik, Yusuf(3)
- Yuncuoglu, Ercument Ugur(3)
- Özdemir, Akın(3)
- Şahin, Engin(3)
- Aymelek, Abdullah(2)
- Birinci, Ahmet(2)
- Dertli, Enes(2)
- Ergün, Mustafa(2)
- Eryılmaz Türkkan, Gökçen(2)
- Gerçek, Yusuf Can(2)
- Gul, Volkan(2)
- Gıdık, Betül(2)
- Kahraman, Yusuf(2)
- Kamiloglu, Aybike(2)
- Kara, Yakup(2)
- Keskin, Merve(2)
- Kul, S.(2)
- Malgaca, Levent(2)
- Nabiyev, Vasif(2)
- Oktay, Mine Gül(2)
- Sefaoglu, Firat(2)
- Turhal, Uğur(2)
- Uslu, Emin(2)
- Uyar, Mehmet(2)
- Uzun Yaylacı, Ecren(2)
- Yaylacı, Murat(2)
- Özkök, Aslı(2)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Enhanced freshwater production in prism-type solar stills using a fresnel lens system with comprehensive energy-exergy and cost analysis
Ceviz, Mehmet Akif; Köksal, Hüseyin; Afshari, Faraz; Muratçobanoğlu, Burak
This study presents the development and performance evaluation of a novel prism-type solar still integrated with a Fresnel lens concentration system designed to concentrate solar radiation on an external spiral heat exchanger. Experimental investigations were conducted under two different saline water flow rates of 0.05 and 0.1 kg/min. The performance of system was comprehensively analyzed in terms of fresh water yield, thermal efficiency, exergy efficiency, and economic viability. The heated saline water and resultant vapor were directed into the prism-shaped condensation chamber, where condensation occurred efficiently. The experimental results demonstrated that lower saline water flow rates led to higher water temperatures and enhanced evaporation rates, thereby increasing freshwater productivity. In contrast, higher flow rates resulted in greater accumulation of saline water within the basin, reducing the evaporation rate and thus lowering overall productivity. The proposed design uniquely combines geometric enhancement via a prism-shaped condensation chamber with solar concentration through a Fresnel lens, enabling a dual-effect improvement in energy absorption and condensation efficiency, an approach not previously reported in the literature for solar desalination systems. The system achieved thermal and exergy efficiencies of 22.95 and 15.50%, respectively, at a saline water flow rate of 0.05 kg/min, producing 92 g of clean water in 60 min. Furthermore, the cost analysis conducted indicated a cost of $0.2546 per liter for this scenario.
AtıfScopus1WoS2OpenAlex3
İncele - MakaleAçık Erişim2026Scopus SJRQ1Gastrointestinal stability and bioactivity of propolis from diverse origins
Can, Zehra; Çelebi, Zeynep Berin; Tunca, Erol; Kolaylı, Sevgi; Sevin, Sedat; Tutun, Hidayet
Propolis is a chemically complex bee product whose biological properties depend on its botanical and geographical origin. However, little is known about how gastrointestinal digestion affects its phenolic profile and bioactivity. In this study, twelve propolis samples from eight countries were evaluated for phenolic and flavonoid contents, antioxidant capacity (FRAP, ABTS+•), and urease inhibition before and after simulated gastric digestion. RP-HPLC–PDA identified 26 phenolic compounds showing substantial compositional diversity. Turkish Bolu propolis retained the highest post-gastric FRAP value, while several samples (BBP, AFP) maintained or enhanced urease inhibition. PCA and HCA highlighted origin-dependent differentiation, identifying digestive stability as a key variable for functional potential.
AtıfOpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ2Physical, chemical and thermal characterization of bacterial nanocellulose produced using sugar beet molasses by Komagataeibacter sp. SB2569
Kara, Adem; Bayram, Sinan
Bacterial nanocellulose (BNC) is a biopolymer synthesized by bacteria utilizing various carbon sources. The biocompatible and biodegradable nature of BNC offers considerable advantages for its application in fields such as medicine, biomedical engineering, cosmetics, food, nanocomposites, and organoelectronics. Nevertheless, the high production costs necessitate the development of more cost-effective and efficient BNC production methodologies. This study aimed to produce BNC utilizing cost-effective sugar beet molasses. To achieve this, bacteria isolated from various vinegar samples were assessed, revealing that the BNC production potential of these isolates ranged from 2.09 to 3.21 g L⁻1. The 16S rDNA gene of the strain with the highest BNC yield was amplified and sequenced, and it was subsequently deposited in the GenBank database as Komagataeibacter sp. SB2569, with the accession number PV231799.1. XRD analysis revealed characteristic diffraction peaks at 14.8°, 16.5°, 22.6°, and 34.5°, confirming the cellulose 1β crystalline structure and high crystallinity of the synthesized BNC. FTIR analysis exhibited characteristic absorption bandsthat, confirming the presence of β-1,4-glycosidic linkages and the cellulose I structure of BNC. TGA analysis showed an initial weight loss of ~ 5% between 0–100 °C, a major degradation of ~ 75% occurring at 220–350 °C with a maximum decomposition rate at 343 °C, and a residual mass of approximately 10–20% remaining above 600 °C. The findings indicate that the Komagataeibacter sp. SB2569 strain holds significant potential for BNC production using low-cost carbon sources.
AtıfScopus1WoS1OpenAlex2İncele - MakaleYalnız künye2026Scopus SJRQ1Profile of honey, bee pollen and bee bread: comparative shotgun sequencing
Morgil, Hande; Ecem Bayram, Nesrin
The plant origin of the bee products often influences their value. Here, we investigated for the first time how the content of bee bread, a functional food with high nutritional value, differs in terms of plant and bacterial taxa in comparison with bee pollen and honey samples, using shotgun sequencing analysis. Sequencing of honey, bee pollen, and bee bread samples yielded approximately 32.74 Gbp of data. Out of a total of 268,964 abundant genes, 70,280 genes (26.13%) were assigned to a taxonomic group according to the supermajority rule. These taxonomic groups were annotated as follows: Kingdom (84.99%), phylum (75.94%), class (73.26%), order (67.21%), and family (65.11%). It was determined that honey, bee pollen, and bee bread samples consisted of large plant families Poaceae, Fabaceae and Asteraceae. This indicates that these taxa are also favored by bees for visiting, and are therefore used as food sources. These differences vary according to the environmental flora of the apiary and may be site specific. Based on these results, DNA-based next-generation sequencing techniques can be successfully used to identify the plant sources of bee products. Thus, the botanical and geographical origin of bee product samples can be more accurately, reliably and in detail identified. Furthermore, this technique can be successfully used to monitor the regional flora and food safety.
- Kitap BölümüAçık Erişim2026Scopus SJRQ4Turkish Students’ Use of NotebookLM in an Online Digital Literacy Course
Kayali, Bünyami; Yavuz, Mehmet
This experimental study investigates the effects of using NotebookLM on students’ academic achievement and students’ assessment of NotebookLM in online digital literacy courses in higher education. It was conducted using an explanatory sequential mixed-methods design. A one-group pretest–posttest model was employed. During a five-week intervention, 33 Turkish students used NotebookLM for summarizing, concept mapping, and scenario-based problem-solving activities. Data was collected from a pretest, posttest, and interviews. Quantitative data was projected into SPSS 27 for analysis, and qualitative data was thematically analysed. Results reveal a significant difference between the pretest score (M = 66.90, SD = 10.26) and posttest score (M = 74.90, SD = 13.16) in terms of academic achievement, t(32) = −3.51, p = 0.001. The effect size was moderate (Cohen’s d = 0.68). Interview data shows that the students perceived NotebookLM as helpful for comprehension, time efficiency, motivation, and feedback, though constrained by language support and occasional technical problems. The findings suggest implications for using NotebookLM in online courses in higher education in Turkey.
- MakaleAçık Erişim2026Scopus SJRQ1Modal parameter determination and structural assessment of historical minaret under earthquake and wind loads
Yanik, Yusuf; Demirtaş, Betül; Yurdakul, Muhammet; Aymelek, Abdullah; Türker, Temel
This study presents a comprehensive linear time history of a historical masonry minaret called the Grand Mosque Minaret in Bayburt, employing a finite element (FE) model subjected to five distinct real earthquake acceleration records. Ambient vibration tests were conducted within the framework of operational modal analysis (OMA), utilizing enhanced frequency domain decomposition technique to estimate the experimental modal parameters. The FE model, developed under the assumption of linear elastic material behavior, was updated through a vibration-based model updating technique to accurately represent the dynamic characteristics of the structure. Each seismic record was applied as a base excitation, and the corresponding time-dependent structural responses were computed for initial and updated FE models. The analysis yielded critical engineering parameters, including maximum displacement and minimum–maximum principal stress distributions. The results obtained from the FE analyses were evaluated comparatively. Also in this study, the wind loads of the minaret were determined using the TS 498 standard, and structural wind load analyses were performed on the initial and updated FE models. Drift ratio values of the minaret were calculated for earthquake records and wind loads, and the structural performance of the minaret was evaluated comparatively for both models. It has been found that the structural behavior of the minaret was significantly affected by earthquakes. The drift ratio values remained within the controlled damage limit for wind analyses, while earthquake analyses indicated that the minaret was mostly in the collapse limit. The results show that more effective conservation and restoration strategies for cultural heritage structures can be developed by using both FE and experimental methods.
- MakaleAçık Erişim2026Scopus SJRQ2Investigation of the Effect of Niobium Addition on Fluidity and Mechanical Properties in Casting of Aluminum Alloys
Çolak, Murat; Yalçin, Önder
Aluminum and its alloys are important engineering materials widely used in the defense industry, industrial production, and machinery industry. Depending on the increase in quality expectations from aluminum casting alloys, castings are made with different alloy element additions. In the study, the effects of Nb addition to A356 aluminum alloy on casting properties were investigated with experimental studies. The Nb addition rate in the alloy was determined as 0.03%, 0.06% and 0.1%. Four-channel fluidity mold with varying section thicknesses, spiral fluidity mold and mechanical test mold were used in casting experiments. As a result, with the addition of Niobium, an increase in maximum tensile strength and % elongation was observed, while a decrease in fluidity properties was observed.
AtıfScopus4WoS5OpenAlex4İncele - MakaleAçık Erişim2026Scopus SJRQ2Investigation of structural, optical and optoelectronic properties of eumelanin pigment
Aksoy Pehlivanoglu, Seval; Bayram, Sinan
In this work, the structural, morphological and optical properties of the eumelanin film fabricated on an FTO substrate were first investigated. Then, the effects of illumination intensitiy on the optoelectronic properties of the device fabricated on p-Si substrate (Eumelanin/p-Si) were investigated. The deposited film was identified as polycrystalline from the XRD pattern. The crystallite size was found to be approximately 13 nm. Surface morphology analysis of the film was carried out using atomic force microscopy (AFM) measurements. The surface roughness value (Rq) of the film was determined to be 55.7 nm. The film’s transmittance in the visible region is approximately 83%. The average refractive index in the visible region was calculated to be 1.39. The value of the eumelanin film was determined using both the Tauc technique and the Kubelka-Munk function. The direct and indirect optical bandgaps of eumelanin were calculated using both the Tauc method and the Kubelka-Munk function. The calculated direct and indirect optical bandgap values are, respectively, 2.79 eV and 1.96 eV for the Tauc method, and 2.65 eV and 1.79 eV for the Kubelka-Munk method. The electronic parameters of Eumelanin/p-Si heterostructure were derived from its characteristics. The charge transport mechanisms controlling the diode behavior of the eumelanin/p-Si structure were investigated and analyzed using the power law relationship. measurements performed at various illumination intensities indicated that the device exhibited photoconductive behavior. All the results obtained from this study demonstrate the potential of eumelanin/p-Si device to be used in photonic applications.
- MakaleYalnız künye2026Scopus SJRQ2Frequency-Based Damage Detection with ANN and Seismic Behaviour Assessment of a Historical Masonry Tower
Demirtaş, Betül; Türker, Temel; Yanik, Yusuf; Dede, Tayfun
Nowadays, Artificial Neural Networks (ANNs) are widely used in damage detection because of their powerful computational and exceptional ability to recognize patterns in historical structures. This paper presents the seismic behaviour assessment and structural damage detection performance of the ANN trained with natural frequencies to identify the damage on the Hagia Sophia Bell Tower in Trabzon, Türkiye. Reduction in the stiffness of the structures causes changes in the structural dynamics. Natural frequencies, being key indicators in damage detection, were utilized as input parameters to train the ANN in this study. The study’s scope included updating of the initial finite element (FE) model constituted with SAP2000 software according to the experimental dynamic characteristics obtained from the Civil Engineering Vibration System developed by our work team. The seismic behaviour of the tower was also examined through time history analyses under the effect of strong earthquakes. The required data for the ANN analyses was obtained from the FE modal analysis of the tower. The ANNs dataset was generated separately by simulating both single and double damage scenarios. Possible twelve damage zones were determined according to the places where the highest stresses occurred in the earthquake analysis of the tower. The reduction in the elasticity modulus of each region defined on the tower was considered as damaging effect and used as ANN output parameter. It was shown that ANN trained with natural frequencies can effectively identify the location and severity of damage.
AtıfScopus6OpenAlex7İncele - MakaleAçık Erişim2026Scopus SJRQ3Molecular structure, spectral characteristics, and nonlinear optical properties of labetalol: an experimental and computational investigation
Çınar, Mehmet; Can, Sümeyra
Labetalol is an antihypertensive agent that possesses both α- and β-adrenergic blocking properties. This characteristic allows for its clinical use in both chronic hypertension and hypertensive emergencies. In this study, the FT-IR, FT-Raman, 1 H, 13 C, and DEPT-135 NMR spectra of labetalol hydrochloride (Labetalol HCl) were recorded and examined. Furthermore, the pharmacologically active (R, R) stereoisomer of labetalol was theoretically investigated using the B3LYP functional and the 6-311++G(d, p) basis set. The theoretically determined ground-state geometry of the molecule showed excellent agreement with experimental data reported in the literature. Using the obtained optimized structure, the vibrational spectra of the molecule were simulated, and the vibrational modes were assigned by evaluating them together with the experimental data. Nuclear Magnetic Resonance (NMR) analysis of the molecule was performed considering experimentally recorded values and calculations for gas phase, DMSO, and chloroform solvent environments, and the chemical shift values for each H and C atom were determined. Using Time-Dependent Density Functional Theory (TD-DFT) and Solvation Model based on Density (SMD) approaches, the UV-Vis spectra of the molecule were obtained in the gas phase and in four different solvent environments (ethanol, methanol, DMSO, and water). To better understand the electronic properties of the molecule, Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential Surface (MEPS), Hirshfeld surface analysis, Mulliken and Hirshfeld charge distributions, and Density States (DoS) analyses were performed. In addition, the non-linear optical (NLO) properties of the molecule were theoretically calculated, and the results showed that the molecule could be a promising NLO candidate.
- MakaleYalnız künye2026Scopus SJRQ2The Effect of Sugar Beet (Beta vulgaris L.) Varieties Grown Under Semi-Arid Conditions in Turkey’s Eastern Anatolia Region on Yield and Quality
Bagcı, Ikram; Gul, Volkan; Sefaoglu, Firat; Lan, Yuzhou; Coban, Furkan
Global climate change, which is increasingly evident today, leads to significant fluctuations in the yield and quality parameters of sugar beet varieties, particularly due to its direct impact on semi-arid regions. Therefore, the adaptation capacity of varieties especially in the semi-arid areas of eastern regions and their responses to drought and temperature stress are of critical importance. This study was conducted during the 2022–2023 growing seasons to evaluate the yield and quality performance of ten sugar beet varieties (Seranada, Lider, Mohican, Terronova, Aranka, Turbata, Bernache, Setenil, Tisserin, and Chevalier) within a continental agro-ecological zone characterized by high altitude and a semi-arid climate. The results revealed significant differences among the varieties in terms of all examined traits. The highest root yield was obtained from Chevalier (95.30 ton/ha) and Mohican (94.17 ton/ha), while Tisserin produced the lowest (71.34 ton/ha). In terms of sugar yield, Terronova ranked highest (16.18 ton/ha), whereas Tisserin (12.44 ton/ha) and Setenil (12.34 ton/ha) showed the lowest performances. The Lider variety recorded the highest sugar content (18.22%), indicating its potential as a quality-oriented genotype. Overall, Mohican and Terronova demonstrated the most favorable responses under semi-arid conditions. These findings underscore the importance of regional variety testing for identifying high-yielding and high-quality sugar beet genotypes, especially in environments affected by altitude, climate variability, and soil characteristics.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2026Scopus SJRQ2Relationship Between Aluminum Liquid Metal Quality and Defects
Kutsal, Umit; Colak, Murat; Ertugrul, Onur
Aluminum alloys are commonly used in various industries today. In order to produce defect-free high-quality alloys with sustainable processes, defects must be reduced, and liquid metal quality must be improved. There are various methods that can be used for the measurement of liquid metal quality. Some of which are density index, bifilm index, K-Mold index, PoDFA, Prefil, fluidity test, and thermal analysis. The relationship and validation between these methods are still not clear. In this study, the relationship between aluminum liquid metal quality and defects is analyzed. Three different conditions were utilized. These conditions are (1) before a controlled degassing, (2) after the controlled degassing and (3) after the liquid metal is transferred to the holding furnace. According to the results, it was observed that the reduction of bifilms index did not reduce other inclusions and did not always favorably affect other measurement methods. It was also observed that the reduction of bifilm index did not improve the porosity level. Moreover, it was found that elongation values are related to the largest defect diameters. Bifilm index are not the only factor affecting the elongation and the density index directly affects the defect distribution. K-Mold index has an impact as it shows macro-inclusions. However, bifilm index, density index, fluidity index and K-Mold index are not as sufficient as numerical calculation of defect size by computed tomography (CT). The main factor directly affecting the elongation and tensile strength was found to be the inclusion size and diameter in the CT result. Examination of the fracture surfaces revealed that oxide contents are present, and the oxygen orientations and aluminum orientations are compatible. This harmony is thought to be related to the orientation of the bifilms in the structure.
AtıfScopus8WoS8İncele - MakaleAçık Erişim2026Scopus SJRQ2Yield Performance and Oil Composition of Safflower (Carthamus Tinctorius L.) Cultivars Under Semi-Arid Conditions in Northern Türkiye
Cosar, Ibrahim; Gul, Volkan; Sefaoglu, Firat
The shortage of vegetable oil in Turkey is escalating daily. Increasing the production of safflower oil seeds, which are particularly adapted to semi-arid climatic conditions, could reduce dependence on foreign sources for vegetable oil. In this study, the yield and quality characteristics of eight safflower varieties were evaluated under semi-arid ecological conditions in northern Turkey. Field trials were conducted over two years (2020–2021) with three replications, following the ‘’Randomized Block Experiment Design’’. Significant differences were observed between the varieties in terms of the examined parameters. The highest average grain yield (1730.9 kg ha⁻¹) was obtained from the Göktürk variety, the highest oil content (30.7%) from the Balcı variety, and the highest oil yield (470.1 kg ha⁻¹) from the Olas variety. The highest oleic acid content (50.14% ± 3.9) was obtained from the Koc variety, and the highest stearic acid content (2.68% ± 0.1) was obtained from the Hasankendi variety. The linoleic acid (77.71% ± 0.4) and palmitic acid (5.92% ± 0.1) ratios were found to be higher in the Dincer variety compared to other varieties. The research highlights the importance of genotypes in asparagus. It demonstrates that the Göktürk and Olas varieties stand out in terms of yield and yield components in semi-arid ecosystems. These results provide variety-specific information for regional adaptation in safflower breeding and under challenging climatic conditions.
- MakaleAçık Erişim2026Scopus SJRQ2Experimental and Modeling Study of Fluidity in Ductile Iron (GGG40)
Coşar, Mehmet; Şüküroğlu, Ebru Emine; Güngör, Kadir; Çolak, Murat
Ductile irons (spheroidal graphite cast irons, SGI) are widely used in automotive and energy systems due to their high strength, ductility, and excellent machinability. The casting quality of these alloys largely depends on the flow and filling behavior of the molten metal, namely its fluidity. In this study, the effects of pouring temperature, filling time, and metallurgical quality on the fluidity of GGG40 ductile iron were investigated through both experimental and numerical approaches. Experimental trials were conducted at pouring temperatures of 1350 °C, 1400 °C, and 1450 °C; metallurgical quality levels of 10%, 50%, and 90%; and filling times of 5 s and 10 s. The fluidity lengths were measured and statistically evaluated. The results revealed that increasing the pouring temperature and metallurgical quality significantly improved fluidity, while shorter filling times allowed the molten metal to travel longer distances before solidification. Modeling studies performed using a commercial casting simulation software showed strong correlation with the experimental data. Microstructural examinations indicated that higher pouring temperatures and improved metallurgical quality led to a more homogeneous distribution of graphite nodules and an increased ferrite fraction in the matrix. The findings provide valuable insights into the influence of process parameters on the fluidity behavior of ductile iron and offer critical design data for enhancing casting quality and productivity in industrial foundry applications.
AtıfScopus1İncele - MakaleYalnız künye2026Scopus SJRQ2Effect of Scandium Addition on Recycled A356 Alloy: Experimental Investigation and CALPHAD-Based Thermodynamic Analysis
Kutsal, Ümit; Barutçuoğlu, Burak; Sağnak, Yiğit; Toker, Abidin; Çatar, Recep; Çolak, Murat
This study systematically investigates the influence of scandium (Sc) additions at 0.1, 0.2, and 0.3 wt.% on the melt quality, microstructural characteristics, fluidity, and mechanical performance of A356 aluminum alloy under recycling-oriented casting conditions. The alloy charge consisted of 20% primary aluminum and 80% recycled scrap, while the Fe content was maintained at 0.2 wt.%. Melt treatment was performed by rotary degassing using a commercial flux. Melt quality was assessed using the Reduced Pressure Test (RPT) and bifilm index analysis, whereas casting performance was evaluated through an eight-channel fluidity test. Mechanical behavior was characterized by tensile and Brinell hardness testing, and microstructural and phase analyses were conducted using scanning electron microscopy (SEM) and X-ray diffraction (XRD). To complement the experimental investigation and provide a thermodynamic basis for interpretation, phase stability, solidification behavior, and phase-fraction evolution were examined using Thermo-Calc within the CALPHAD framework. By combining experimental characterization with computational thermodynamic analysis, this study elucidates the effect of Sc content on the processing–microstructure–property relationships of recycled A356 alloys and provides a systematic basis for evaluating Sc modification in high-recycled-content aluminum castings.
- MakaleAçık Erişim2025Scopus SJRQ2Importance of Melt Cleaning Parameters on Reliability of Tensile Properties in A356 Alloy
Tigli, Ahmet; Uslu, Emin; Çolak, Murat; Dispinar, Derya
This study examines how melt treatment and pouring temperature affect the microstructure and mechanical properties of A356 aluminum alloy. Samples were cast under degassed, non-degassed, and upgassed conditions at 725, 750, and 775 °C. Melt quality was assessed using the reduced pressure test (RPT) and the bifilm index (BI), while microstructural features were analyzed via SEM and EDS. Tensile testing and Weibull statistics were used to evaluate mechanical performance and variability. Results showed that by improper degassing the reproducibility of mechanical properties decreased regardless of hydrogen content of the melt. When bifilm index (BI) was high (> 50 mm), the ductility was lowered and caused greater variability in strength and elongation. SEM confirmed large oxide films in samples, linked to the brittle fracture. The work also highlighted the importance of melt cleaning parameters for the reliability of cast aluminum alloys regardless of the hydrogen content.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ2A novel exopolysaccharide from cold-adapted yeast Rhodotorula glutinis, along with structural, rheological, antioxidant, and antibiofilm properties
Oztekin, Sebahat; Dikmetas, Dilara Nur; Karbancıoglu-Guler, Funda
In the present study, a novel exopolysaccharide EPS-BMD26 produced by cold-adapted yeast Rhodotorula glutinis was structurally examined, along with its rheological, antioxidant, and antibiofilm properties. High-performance liquid chromatography (HPLC) analysis revealed glucose and galactose as two monosaccharide constituents. The functional groups within the EPS-BMD26 structure were detected by Fourier transform infrared (FT-IR) spectroscopy. The 1H and 13C nuclear magnetic resonance (NMR) spectra of EPS-BMD26 also confirmed its β-D-glucan type with galactose residues with an average molecular weight of 118 kDa. Differential scanning calorimetry (DSC) analysis revealed that EPS-BMD26 had a high level of thermal stability, up to 326.16 °C. Scanning electron microscopy (SEM) analysis demonstrated that EPS-BMD26 had a porous microstructure with fissures. X-ray diffraction (XRD) analysis revealed its semi-crystalline nature. EPS-BMD26 showed moderate and concentration-dependent antioxidant potential recruiting different methods, including •OH, DPPH•, CUPRAC, and ABTS radical scavenging activities. Water-soluble EPS-BMD26 exhibited high water holding capacity of 190 ± 0.22% with a water solubility index of 60.6 ± 8.3%. At 1.25 mg mL-1, EPS-BMD26 inhibited biofilm formation of Staphylococcus aureus ATCC 25923 by 79.5%. Rheological characterization revealed that the aqueous solution of EPS-BMD26 had shear thinning and pseudoplastic behavior. Given these properties, EPS-BMD26 may be a promising bio-hydrocolloid, antibiofilm agent, and food additive for industrial applications.
AtıfScopus15WoS15OpenAlex17İncele - MakaleAçık Erişim2025Scopus SJRQ2Performance analysis of piezoelectric-based energy harvesting in reinforced concrete buildings under seismic and live loads
Ergün, Mustafa; Uyar, Mehmet; Malgaca, Levent
The demand for autonomous energy solutions in seismic regions is increasing for the uninterrupted operation of structural health monitoring systems. In this context, energy harvesting systems offer a solution for low-power devices, especially in earthquake zones where external energy sources may be interrupted. This study evaluates the energy harvesting capacity of a piezoelectric energy harvesting mechanism placed at specific locations in the columns of a reinforced concrete structure, considering both earthquake and live load conditions. A smart building model is developed by placing sensor modules with piezoelectric material on the columns of a three-story reinforced concrete building. The finite element model of the smart building, which is formed by integrating various technologies and sensors, is created in ANSYS, and specific locations on the columns are selected as sensor points. Dynamic analyses are performed under earthquake conditions by considering seismic records from the Imperial Valley, Erzincan, and Darfield earthquakes. Experimental results of a smart structure with patched piezoelectric material are used to verify the simulation results. The voltage, current, and power responses obtained from the sensor points are examined with the payload effect placed at the end point of the sensor module. When the power values collected from the sensor points are compared, it can be said that the maximum power obtained from the smart building under both earthquake and live load is 0.355 W, while the minimum power value reaches 0.168 W. The results show that the energy harvesting mechanism can provide external power to support electronic devices in regions where earthquake effects are frequent and high. Thus, this study presents an innovative contribution to smart building systems by investigating the energy harvesting potential under earthquake and live loads in a reinforced concrete structure equipped with piezoelectric sensors. The model, validated with numerical and experimental analyses, proposes a sustainable energy source for structural health monitoring systems in seismic regions.
AtıfScopus1WoS1OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ2Evaluation of Fe Content on the Fluidity of A356 Aluminum Alloy by New Fluidity Index
Durmuş, Melek; Dispinar, Derya; Gavgali, Mehmet; Uslu, Emin; Çolak, Murat
Elements that are deliberately added to aluminum alloys or are incorporated into the alloy later depending on the production process affect the final product properties. In addition, liquid metal cleaning is important in minimizing undesirable elements. Considering the production process, one of the most harmful impurities that is likely to pass into the alloy via diffusion for aluminum is the element, Fe. It is known that this is due to the fact that although Fe is highly soluble in liquid aluminum and its alloys, it has very little solubility in solids. Depending on the Fe content, mechanical properties, porosity and fluidity properties are affected in aluminum alloys. In this study, stainless and carbon steel rods were dipped into the melt at 700 °C and 750 °C for 1, 2 and 5 h. Castings were performed before and after degassing. Four-channel fluidity mold with different section thickness was used in the trials. Additionally, microstructure characterization was performed under varying casting conditions. Fluidity Index was proposed which is a single value measured from all fluidity values in different sections. When the results were examined, it was determined that the diffusion material, holding time, casting temperature and liquid metal cleanliness had an effect on the fluidity. Due to the increase in diffusion time, a decrease in fluidity was observed in both carbon steel and stainless steel. It was found that fluidity was significantly reduced when using stainless steel.
AtıfScopus14WoS14OpenAlex15İncele - MakaleAçık Erişim2025Scopus SJRQ2Determining errors in force measurements for colloids close to contact
Yücel, Harun
Due to diffraction patterns in light microscopy, the overlapping of colloid images introduces minor errors in determining particle positions, which affecting the accuracy of observing interactions between colloids near contact. This study quantitatively investigates the errors arising from the overlapping effect in force measurements between two closely positioned colloids using digital video microscopy (DVM). For this aim, computer simulations were conducted to obtain the positions of two optically trapped colloids interacting based on a force model and particle images were generated as a time series using experimental particle intensity profiles for two different particle sizes. These generated images were analyzed using tracking algorithms from the literature and the interaction forces were extracted and compared with theoretical force values. The results demonstrated that diffraction patterns significantly influence the accuracy of particle position detection and interaction force calculations. Large diffraction patterns and intensity fluctuations in an image introduce significant errors. However, these errors can become significantly smaller in the presence of large forces and may therefore be considered negligible.