Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 2Citation - Scopus: 1Cross-Linked Carboxymethyl Cellulose Biosorbent for Zinc Removal: a Sustainable Remediation of Heavy Metal-Polluted Waters(Springer Heidelberg, 2025) Celgan, Dilber; Karadag, Asiye; Karim, Barna Jalaluddin Mohammad; Recepoglu, Yasar Kemal; Arar, OzgurThis study focuses on the preparation and characterization of cross-linked carboxymethyl cellulose (CMC) biosorbent for efficient removal of Zn2(+) ions from aqueous solutions. The microstructural features of the biosorbent were examined using scanning electron microscopy (SEM), while elemental analysis was conducted using an elemental analyzer to determine carbon (C), hydrogen (H), nitrogen (N), and sulfur (S) content. Fourier transform infrared (FTIR) spectroscopy was employed to identify functional groups within the biosorbent. Sorption experiments revealed that increasing the biosorbent dose led to higher Zn2(+) removal rates until equilibrium was reached. The optimal pH for Zn2(+) removal was determined to be >= 5, attributed to the conversion of acetate group to its ionic form. Rapid kinetics were observed, with 99% removal achieved within 5 min. The biosorbent exhibited a maximum sorption capacity of 10.809 mg/g and a removal rate of 99% at pH 5. Desorption studies demonstrated efficient Zn2(+) recovery using 0.25 M HCl solution, with a total desorption rate exceeding 99%. The findings indicate the potential for cost-effective regeneration of the biosorbent using dilute acid solutions, enhancing its sustainability and practical applicability in water purification processes. Additionally, the biosorbent's selectivity for Zn2(+) ions over competing ions and its effectiveness in treating real water samples, including those containing Na+, K+, Ca2(+), and Mg2(+), highlight its suitability for practical water purification applications.Article Numerical Study of Breaching at Upper Parts of Homogenous Earthen Dams(Springer Heidelberg, 2025) Dumlu, Emre; Guney, Mehmet Sukru; Okan, Merve; Ozden, Guerkan; Tayfur, GokmenIn this study, time-dependent finite element analyses of the breaching process in two homogenous earth-fill dams were performed using the finite element method. Breaching was initiated at the middle and corner sections of the upper part of the dam bodies. The numerical results were compared with the findings of the experiments realized on dams 60 cm high, 2 m wide at bottom, 20 cm wide at crest with 1 V:1.5H side slopes at upstream and downstream faces. This numerical study combines time-dependent hydraulic gradient distributions and groundwater flows to assess breach areas, velocities, and flow rates. A Python algorithm was integrated with the Jupyter console, allowing the simulation of the breach mechanism in multiple runs to determine breach parameters. Both numerical and experimental analyses revealed that the dams were exposed to backward erosion, starting at the downstream side of the dam and progressing inward. The compatibility between experimental and numerical results was sought by means of the parameters RMSE, MAE and the statistical performance of the numerical approach was evaluated by using RSR, NSE, and PBIAS. A fairly good agreement was obtained between the experimental and numerical results.Article Citation - WoS: 1Citation - Scopus: 1Abnormally Accumulated Gm2 Ganglioside Contributes To Skeletal Deformity in Tay-Sachs Mice(Springer Heidelberg, 2024) Demir, Secil Akyildiz; Seyrantepe, VolkanTay-Sachs Disease is a rare lysosomal storage disorder caused by mutations in the HEXA gene, responsible for the degradation of ganglioside GM2. In addition to progressive neurodegeneration, Tay-Sachs patients display bone anomalies, including kyphosis. Tay-Sachs disease mouse model (Hexa-/-Neu3-/-) shows both neuropathological and clinical abnormalities of the infantile-onset disease phenotype. In this study, we investigated the effects of GM2 accumulation on bone remodeling activity. Here, we evaluated the bone phenotype of 5-month-old Hexa-/-Neu3-/- mice with age-matched control groups using gene expression analysis, bone plasma biomarker analysis, and micro-computed tomography. We demonstrated lower plasma alkaline phosphatase activity and calcium levels with increased tartrate-resistant acid phosphatase levels, indicating reduced bone remodeling activity in mice. Consistently, gene expression analysis confirmed osteoblast reduction and osteoclast induction in the femur of mice. Micro-computed tomography and analysis show reduced trabecular bone volume, mineral density, number, and thickness in Hexa-/-Neu3-/- mice. In conclusion, we demonstrated that abnormal GM2 ganglioside accumulation significantly triggers skeletal abnormality in Tay-Sachs mice. We suggest that further investigation of the molecular basis of bone structure anomalies is necessary to elucidate new therapeutic targets that prevent the progression of bone symptoms and improve the life standards of Tay-Sachs patients.Article Citation - WoS: 3Citation - Scopus: 2Development of Transition Metal Oxide Platforms for Aptasensing of Psa in Cell Cultures(Springer Heidelberg, 2024) Kirlangic, Irem Aydin; Uner, Goklem; Kara, Pinar; Kirmizibayrak, Petek Ballar; Ertas, Fatma NilIn this study, a novel aptasensor based on a transition metal oxide-modified pencil graphite electrode (PGE) was developed for the diagnosis of early-stage prostate cancer (PCa) via monitoring the prostate-specific antigen (PSA), which is the main biomarker for PCa. Single-use PGEs modified with pulsed deposited manganese oxide (MnOx) film were used to attach the amino-terminated aptamer specific to the PSA via carbodiimide chemistry. The designed aptasensor was placed in an electrochemical cell containing ferri/ferrocyanide ions as a redox probe to measure the charge transfer resistances (Rct) of the electrode surface by electrochemical impedance spectroscopy (EIS) to follow the response of each modification step. The effect of the medium pH on the ionic structure of the aptamer molecule according to its pI value and, thus, the reversing of the direction of the response (Delta Rct) by the pH change was also discussed. The level of PSA secreted from PCa cells was investigated using impedimetric transduction. The specificity of the aptasensor was validated through selectivity studies against non-specific tumor markers like VEGF and different cancer cell lines including breast cancer and androgen-insensitive prostate cancer. The developed system showcases a label-free, fast, specific, and cost-effective approach for PSA detection, highlighting the importance of medium pH and the electrostatic environment on the aptamer's response. Our work emphasizes the potential for such aptasensors in clinical diagnostics and paves the way for further exploration into using transition metal oxides in biosensing applications.Article A Methodology Providing New Insights Into the Flow Patterns of Karst Aquifers: an Example From Sw Türkiye(Springer Heidelberg, 2024) Maramathas, Athanasios; Katsanou, Konstantina; Sagir, Cagdas; Baba, Alper; Lambrakis, NikolaosThis paper presents a new and innovative methodology for the investigation of karst systems using spring discharge. The behaviour of springs in phase space is investigated by plotting the measurements of spring discharge versus the measurements of the water level at the spring's outlet. Such a diagram reveals new features of the function of the karst system and the discharge pattern of the spring that are not captured by common research methods. The application of this method to the Azmak Spring in southwestern T & uuml;rkiye revealed the existence of five distinct discharge subsystems that operate alternately and never simultaneously. They have a specific connection between them, while the transition from one to another is not random but follows a pattern. An attempt was made to interpret these features using concepts from percolation theory.Article Citation - WoS: 13Citation - Scopus: 17Convenient Site Selection of a Floating Pv Power Plant in Türkiye by Using Gis-Fuzzy Analytical Hierarchy Process(Springer Heidelberg, 2024) Karipoglu, Fatih; Koca, Kemal; Ilbahar, EsraFloating photovoltaics (FPVs) are appearing as a promising and an alternative renewable energy opinion in which PV panels are mounted on floating platforms in order to produce electricity from renewable energy on water such as seas, dams, rivers, oceans, canals, fish farms, and reservoirs. So far, such studies related to the body knowledge on financial, technical, and environmental aspects of installation of FPV have not been performed in Turkey while expanding steadily in other countries. In this study, suitable site selection for installation of FPV power plants on three lakes in Turkey was studied by performing geographic information system (GIS) and the fuzzy analytic hierarchy process (FAHP) as multi-criteria decision-making (MCDM) method. This detailed study revealed that the criterion of global horizontal irradiance (GHI) was determined as the most crucial criterion for the installation of FPV on Beysehir Lake, Lake of Tuz, and Van Lake. Additionally, it was clearly seen that the Beysehir Lake had the highest value approximately 52% among other lakes for installation, that is why Beysehir Lake is selected as the best option for installation of an FPV system with this multi-criteria approach.Article Citation - WoS: 4Citation - Scopus: 6A Sustainable Clean Energy Source for Mitigating Co<sub>2</Sub> Emissions: Numerical Simulation of Hamit Granitoid, Central Anatolian Massif(Springer Heidelberg, 2024) Ayzit, Tolga; Singh, Mrityunjay; Chandrasekharam, Dornadula; Baba, AlperT & uuml;rkiye relies on coal-fired power plants for approximately 18 GW of annual electricity generation, with significantly higher CO2 emissions compared to geothermal power plants. On the other hand, geothermal energy resources, such as Enhanced Geothermal Systems (EGS) and hydrothermal systems, offer low CO2 emissions and baseload power, making them attractive clean energy sources. Radiogenic granitoid, with high heat generation capacity, is a potential and cleaner energy source using EGS. The Anatolian plateau hosts numerous tectonic zones with plutonic rocks containing high concentrations of radioactive elements, such as the Central Anatolian Massif. This study evaluates the power generation capacity of the Hamit granitoid (HG) and presents a thermo-hydraulic-mechanical (THM) model for a closed-loop geothermal well for harnessing heat from this granitoid. A sensitivity analysis based on fluid injection rates and wellbore length emphasizes the importance of fluid resident time for effective heat extraction. Closed-loop systems pose fewer geomechanical risks than fractured systems and can be developed through site selection, system design, and monitoring. Geothermal wellbore casing material must withstand high temperatures, corrosive environments, and should have low thermal conductivity. The HG exhibits the highest heat generation capacity among Anatolian granitoid intrusions and offers potential for sustainable energy development through EGS, thereby reducing CO2 emissions.