Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Ayhan, Nagihan Karaaslan(2)
- Torgut, Gulben(2)
- Acikses, Aslisah(1)
- Akça, Muhammet Esat(1)
- Aydin, Ayşe Nur(1)
- Ayikurt, P.(1)
- Demir, Ferhat(1)
- Dogan, A.(1)
- Doğan, Fatih(1)
- Duru, Erhan(1)
- Erdemoğlu, Murat(1)
- Erust, C.(1)
- Fiedler, B.(1)
- Höchstötter, K.H.(1)
- Incesu, Rabia(1)
- Kanca, Muhammed Sait(1)
- Karacahan, M.K.(1)
- Karaman, Altuğ(1)
- Kök, Mediha(1)
- Kısmet, Y.(1)
- Pekdemir, Mustafa Ersin(1)
- Pıhtılı Yıldız, Güzin(1)
- Serdar, Osman(1)
- Sis, Hikmet(1)
- Tanyol, Mehtap(1)
- Taşgin, Yahya(1)
- Torğut, Gülben(1)
- Uysal, T.(1)
- Uysal, Turan(1)
- Yazdıç, Ferit Can(1)
- Yilmaz, Mücahit(1)
- Ünal, Ceren Erust(1)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ3Investigation of Dielectric Constant and Electrical Conductivity of Poly(MA-co-MMA)/Ce(NO3)3 Composites by Response Surface Methodology for Advanced Dielectric Applications
Torgut, Gulben; Incesu, Rabia
In this study, poly(maleic anhydride-co-methyl methacrylate) [poly(MA-co-MMA)] copolymer and their Ce(NO3)3-filled composites were synthesized and systematically investigated. The copolymer was prepared via free radical polymerization using azobisisobutyronitrile (AIBN) as the initiator in 1,4-dioxane medium. Poly(MA-co-MMA)/Ce(NO3)3 composites were fabricated through a solution mixing technique in accordance with the response surface methodology (RSM) design. Fourier transform infrared spectroscopy (FTIR) results indicated that no significant chemical interaction occurred between the polymer molecule and Ce(NO3)3 particles. Scanning electron microscopy (SEM) images revealed a relatively uniform dispersion of Ce(NO3)3 particles within the polymer, resulting in a rougher surface with increasing filler content and that aggregation occurs at 20 wt%. The presence of Ce(NO3)3 particles in the polymer was confirmed by x-ray diffraction (XRD) analysis. The effects of frequency, applied voltage, and Ce(NO3)3 content on dielectric constant (epsilon) and electrical conductivity (sigma) were optimized using RSM, and the significance of these parameters was evaluated by analysis of variance (ANOVA). An increase in Ce(NO3)3 content significantly enhanced the electrical conductivity, while the applied voltage exhibited no statistically significant effect on dielectric properties. ANOVA results identified Ce(NO3)3 content as the most influential parameter in the developed model.
- MakaleAçık Erişim2026Scopus SJRQ3Determination of Oxidative Stress Responses Induced by the Combination of 4 Different Rare Earth Elements in Dreissena polymorpha; [Determinacija odgovorov na oksidativni stres, ki ga povzroča kombinacija 4 različnih redkih zemljinskih elementov v Dreissena polymorpha]
Serdar, Osman; Aydin, Ayşe Nur
Rare Earth Elements (REE), whose usage areas are increasing day by day, are increasing in the amount of mixing with the environment, causing changes in antioxidant enzyme activities by causing oxidative stress in living organisms. In this study, it was aimed to examine the oxidative stress responses induced by the mixture of 4 different REEs (terbium, gadolinium, Lanthanum, Praseodymium) in Dreissena polymorpha. For this purpose, sublethal concentration values were determined by literature review. Experimental application was carried out within 24 and 96 hours. In the analyzes performed to determine biomarker responses, samples taken from living organisms were weighed and homogenization processes were performed for the analysis of samples taken from the experimental groups, including the control group. After homogenization, samples were centrifuged at 4.000 rpm for 15 minutes. Supernatants were kept at -86 °C until measurements were made. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, and glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) levels were determined using ELISA kits. Statistical analyses were performed using SPSS. One-way ANOVA (Duncan’s multiple range test; p < 0.05) was used for comparison of measured parameters among groups. As a result of the application, a decrease in CAT activity and GSH level and an increase in TBARS levels were observed after 96 hours compared to the control group, while no statistically significant difference was detected in SOD and GPx activities.
- MakaleYalnız künye2026Scopus SJRQ3Optimization and Modeling of Brilliant Yellow Removal Via Neodymium-Infused Polymeric Hydrogel: A Central Composite Design Study
Pıhtılı Yıldız, Güzin; Tanyol, Mehtap; Demir, Ferhat
This study investigates the adsorption performance of a neodymium (III)-reinforced Poly(acrylamide-co-N-vinylimidazole) hydrogel composite [P(AAm-co-NVI)/Nd3+] for the removal of brilliant yellow (BY) dye from aqueous media. The hydrogel structure and metal–polymer interactions were characterized using FT-IR, TGA, SEM, and XRD analyses. The adsorption process was systematically optimized using a central composite design (CCD) approach combined with response surface methodology (RSM). The CCD-RSM second-order model exhibited a good fit to the experimental data (R2 = 0.9350), as supported by ANOVA. Numerical optimization revealed a maximum removal efficiency of 99.13% at a hydrogel dosage of 0.08 g/100 mL, an initial BY concentration of 81.68 mg/L, and a contact time of 61.73 min. Langmuir and the Freundlich isotherms were used in modeling the adsorption data. When the correlation coefficients of both models were compared, it was observed that the Langmuir isotherm provided a better fit for adsorption. The enhanced adsorption performance is attributed to the presence of Nd3+ ions, which promote additional electrostatic interactions and coordination sites between the hydrogel matrix and anionic dye molecules. The results demonstrate that Nd3+-reinforced hydrogels can serve as efficient and tunable adsorbent systems, particularly when process parameters are optimized statistically.
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İncele - MakaleAçık Erişim2025Scopus SJRQ3Optimization of rare earth elements recovery from Kızıldag (Karaman-Türkiye) shale ore using response surface methodology
Uysal, Turan; Ünal, Ceren Erust; Akça, Muhammet Esat; Sis, Hikmet; Erdemoğlu, Murat
In this study, the usability of bauxite-related shale ore, rich in Rare Earth Elements (REEs), to produce REEs, which have high added value and critical importance, was investigated. In this context, Kızıldag (Karaman-Türkiye) shale ore, was prepared for tests through size reduction and sampling processes. HCl leaching was performed at different acid concentrations, leaching times, leaching temperatures, and liquid/solid ratios to determine the optimum leaching conditions for the milled ore. The modeling and optimization parameters related to leaching recovery were investigated using the response surface method (RSM). The results were evaluated using analysis of variance, three-dimensional graphs were drawn, and the accuracy of the models was discussed. Accordingly, optimum values were found, and the REE leaching recovery corresponding to these optimum values was 49.13%. It was concluded that the optimization results were compatible with the experimental results, and the average error rate (6.35%) was low.
AtıfScopus3OpenAlex4İncele - 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 SJRQ2A Novel CuAlMnFe/CeO2 Composite Alloy: Investigating the Wear and Corrosion Features
Doğan, Fatih; Duru, Erhan
Shape memory alloys (SMAs) are known for their exceptional mechanical properties, particularly their superior wear resistance compared to conventional alloys with similar surface hardness. Rare earth oxides are often used as additives to further improve these characteristics. This study investigates the effects of different CeO2 (cerium dioxide) concentrations (0.01 wt.%, 0.1 wt.%, 0.5 wt.%, and 1.0 wt.%) on the properties of CuAlMnFe alloys produced via powder metallurgy (PM). Various analyses were performed, including scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD), as well as hardness, wear, and corrosion tests. The increase in wear rate is closely related to the formation of precipitates from CeO2 addition. Improvements in wear resistance and hardness are attributed to the effects of grain refinement and solid solution strengthening due to CeO2. Specifically, the wear rate increased from 1.5 × 10−3 mm3/(Nm) to 3.4 × 10−3 mm3/(Nm) with higher CeO2 content. Additionally, the friction coefficient of the CuAlMnFe alloy was reduced with CeO2 addition, indicating enhanced frictional properties. The optimal CeO2 concentration of 0.5% was found to improve grain uniformity, resulting in better wear resistance. Incorporating CeO2 particles into CuAlMnFe alloy enhances hardness and reduces wear rate when used in appropriate amounts. Additionally, it exhibits superior corrosion resistance, as evidenced by a positive shift in corrosion potential in Tafel measurements in solutions and a decrease in corrosion current density. The C0.5 specimen showed the highest corrosion potential (Ecorr, −588 V) and the lowest corrosion current density (icorr, 6.17 μA/cm2) during electrochemical corrosion in 3.5 wt.% NaCl solution.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ2Physical and shielding properties of Er2O3 rare earth oxide compound content on PCL/PEG blend
Taşgin, Yahya; Pekdemir, Mustafa Ersin; Yilmaz, Mücahit; Kanca, Muhammed Sait; Kök, Mediha
Rare earth elements (RRE), due to their unique magnetic, electrical, and optical properties, are an important group of elements demanded in many application areas from machine technology to the health industry. In this study, new composites were obtained by mixing Erbium oxide (Er2O3), one of the rare earth element oxides, into PCL–PEG blend, which is also an important material group, in different ratios. The characteristic functional groups of the obtained polymer blend/Er2O3 nanocomposites were determined by the ATR-IR, and as the erbium oxide ratio increased, characteristic peaks of the polymers in the blend as well as characteristic signals of the Er–O–Er bond were found. When the thermal behavior of the obtained composites was examined, it was observed that the polymer blend exhibited miscible blend properties and the melting temperature of the polymer blend increased as the Er2O3 ratio increased. In addition, it was determined that the thermal stability of the composite increased significantly. X-ray measurements of composites at room temperature support other measurement results. It was determined that the presence of Er-RRE oxide increased the crystal structure feature in the polymer blend composite. Gamma radiation shielding capabilities of polymer materials containing different erbium ratios were investigated by calculating shielding parameters such as half value layer (HVL), radiation protection efficiency (RPE), and mean free path (MFP). Cs-137 and Co-60 radioactive sources were used as gamma sources. According to the obtained measurement results, Erbium oxide increased the absorption property of the polymer composite material. Graphical abstract: [Figure not available: see fulltext.].
AtıfScopus26WoS28OpenAlex29İncele - MakaleYalnız künye2023Scopus SJRQ1Improving dielectric properties, electrical conductivity, and thermal properties of biodegradable polymer composites prepared with lanthanum
Torgut, Gulben; Ayhan, Nagihan Karaaslan; Acikses, Aslisah
The precipitation method was adapted to synthesize the poly(ε-caprolactone-copolymer- ethylene oxide) (ε-CL-co-EO) composite with the salt of lanthanum (La), a rare earth element. This salt was incorporated into the polymer of different weight percentages to study how it affects the thermal and dielectric properties of the polymer. The resulting products were characterized by Fourier Transform Infrared Spectroscopy, X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and thermogravimetric analysis. XRD and SEM data show that the polymer mixes homogeneously with the metal salt. Thermal degradation data show that the thermal stability of composites synthesized with La is lower than that of pure polymer. The dielectric properties and A.C conductivity measurements of the composites were investigated by using impedance analyzer in the frequency range (100 Hz to 20 kHz) at room temperature. The electrical property results of (ε-CL-co-EO)/La composites displayed that dielectric constant (έ), dielectric loss (ε"), tan delta (tan δ) and A.C electrical conductivity (σac) increase with increasing La content. The largest conductivity of (ε-CL-co-EO)/La composite filled with 20 wt% La was 8.80 × 10−8 S/cm, which was 162% times pure (ε-CL-co-EO). In addition, impedance (IZI) of composites was evaluated from the dielectric data. This procedure is eco-friendly and easy to handle, which provides a promising route to polymer composites in the application of the conductivity field.
AtıfScopus6WoS6OpenAlex7İncele - Derleme MakaleYalnız künye2023Scopus SJRQ1Hydrometallurgical Roadmaps and Future Strategies for Recovery of Rare Earth Elements
Erust, C.; Karacahan, M.K.; Uysal, T.
Increasing demand for low carbon technologies and renewable energy sources requires our resources and economies to be circular. Many countries agree that the responsible consumption, production, and recycling of rare-earth-containing products is essential as a way to achieve the sustainable development goals also set out in the European Green Deal. Sustainable sourcing is targeted with carefully designed roadmap for cost efficient REE production from end-of-life products (EoLs) in addition to mining activities as providing primary sources. Hydrometallurgical methods, such as roasting, leaching, precipitation, crystallization, solvent extraction, and ion exchange includes fast developing, selective, eco-friendly, and cost-effective technologies especially for the extraction of REEs. This article provides an overview of primary and secondary resources and summarizes presents case scenario of studies carried out on the use of some promising methods, which could serve as an economical means for recovering REEs.
AtıfScopus46WoS46OpenAlex51İncele - MakaleYalnız künye2023Scopus SJRQ2Antibacterial activity of novel synthesized chitosan-graft-poly(N-tertiary butylacrylamide)/neodymium composites for biomedical application
Yazdıç, Ferit Can; Karaman, Altuğ; Torğut, Gülben; Ayhan, Nagihan Karaaslan
In this present study, composites of chitosan-graft-poly(N-tertiary butylacrylamide) (CH-graft-poly(N‑tert‑BAAm)) copolymer, with Neodymium (Nd), an important rare earth element, were prepared by precipitation technique. Nd was successfully incorporated into the polymer of different weight percentages (0.5%, 1%, and 2%) without any degradation. The effect of neodymium additives on the structural, morphological, and antibacterial activities against gram-positive bacteria and gram-negative bacteria of the polymer was analyzed using various instrument techniques. X-ray diffraction (XRD) results together with Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) studies confirmed the morphology of Nd-doped CH-graft-poly(N‑tert‑BAAm) composites without any other impurities. The antibacterial effect of Nd was studied by adding it to the copolymer in a weight ratio of 0.5%–2%. The antibacterial effect of neodymium concentration on four different strains of bacteria was investigated: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (DSM 50071) (P. aeruginosa), Bacillus subtilis (DSM 1971) (B. subtilis), and Staphylococcus aureus subsp. aureus (ATCC 25923) (S. aureus). The antibacterial activities of the obtained composites were determined using the Agar Well Diffusion Assay Method. Experimental results show that Nd binds well to CH-graft-poly(N‑tert‑BAAm). Activity against E. coli, P. aeruginosa, B. subtilis, and S. aureus subsp. aureus creates a potential for pharmaceutical and biomedical applications.
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