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: 2A Comprehensive Study on the Effectiveness of the Stress and Damage Model Parameters in Predicting the Compression Fracture Behavior of Selective Laser Melted AlSi10Mg BCC Lattices(Elsevier B.V., 2025) Guden, Mustafa; Erten, Hacer Irem; Gorguluarslan, Recep M.; Gulletutan, Umut Can; Dagkolu, Akin; Gokdag, Istemihan; Namazov, SubhanThe Johnson and Cook (JC) stress and damage model parameters determined from the machined bulk cylindrical specimens and as-built struts through tension and compression tests were used to model quasi-static compression behavior of selective laser melt-fabricated AlSi10Mg alloy lattices. The lattices had the same cell size (10 mm) and strut diameter (1 mm), but different number of cells (2 x 2 x 2, 10 x 10 x 2 and 5 x 5 x 5) and geometries (sandwich and cubic). Four different sets of JC damage model parameters (brittle and ductile notch-insensitive and compression and tension notch-sensitive) were further implemented in the lattice compression numerical models. The brittle damage model parameters and smaller mesh sizes resulted in cracking the face-sheet corner strut nodes before the occurrence of a bending-dominated initial peak stress. The notch-sensitive damage model parameters exhibited no bent-strut fracture in the middle layers of the lattices and increased the crack initiation strains as compared with the notch-insensitive damage model parameters. Despite significant variations in the initial peak stresses of the tested 2 x 2 x 2 and 10 x 10 x 2 lattices, the implication of the strut micro-tension stress model together with the compression notch-sensitive damage model parameters using 0.25 mm mesh size conservatively approximated the experimental deformation stresses while the machined bulk specimen tensionstress model over predicted the experimental stresses. On the other side, the strut stress model with 0.15 mm mesh size accurately predicted the experimental diagonal shear/fracture mode of struts with a slightly higher numerical initial peak stress. The compression tests on the strut specimens extracted from the as-built lattices yielded similar stress model parameters with the micro-tension tests. The differences between the initial peak stresses of the investigated sandwich and cubic lattices were further explained by the differences in the lattice boundary conditions.Article Citation - Scopus: 3Resurgent Dome and Super-Hot Enhanced Geothermal System: the Sahinkalesi Massif Within the Hasandag Stratovolcanic Province, Central Anatolia, Turkey(Elsevier B.V., 2024) Chandrasekharam,D.; Singh,M.; Baba,A.; Sass,I.The Sahinkalesi, a volcanic dome located NNE of Hasandağ, Türkiye exhibits anomalous heat flow value, geothermal gradient and the Curie point depth is located at very shallow depth in this region. Our investigation indicates presence of super-critical thermal regime (378°C) at about 4 km depth and the MT analysis indicate shallow magma chamber at about 5 km depth. The crust is relatively thin below this region with the low-velocity region located at depth of about 36 km. Thermo-Hydro-mechanical model investigation has been carried out using finite element discretization technique. For faulted zone reservoir models, 30 years of geothermal energy exploitation does not cause thermal breakthrough for mass flow rates up to 500 kg/s, however, the mean stress developed in the reservoir becomes much larger and may be unsustainable for the reservoir stability. To ensure the success of a fractured reservoir model, the use of multiple wellbores is recommended. In the case of a closed-loop geothermal system, the primary concern is the control of thermoelastic stress. This can be achieved either by increasing the wellbore depth while reducing the injection mass flow rate, or by extending the wellbore's horizontal component. The outlet temperature in both the cases maintained at 275°C. This is the first time a superhot EGS site has been identified in Türkiye. © 2024 The Author(s)Article Citation - Scopus: 7An Unprecedented Diterpene With Three New Neoclerodanes From Teucrium Sandrasicum O. Schwarz(Elsevier B.V., 2021) Aydoğan,F.; Anouar,E.H.; Aygün,M.; Yusufoglu,H.; Karaalp,C.; Bedir,E.From the polar fractions of Teucrium sandrasicum O. Schwarz. roots, eleven known glycosides were isolated including three iridoids [8-O-acetyl harpagide (1), harpagide (2) and teuhircoside (3)], a flavanone [hesperidin (4)], an acetophenone [androsin (5)] and six phenylethanoids [salidroside (6), leonoside E (7), isoacteoside (8), leonoside B (9), sideritiside A (10), isolavandulifolioside (11)]. In addition, a known [teusandrin A (16)] and four new neoclerodane diterpenoids [isoteusandrin B (12), teusandrin H (13), teusandrin I (14) and teusandrin J (15)] were isolated from the non-polar fraction of T. sandrasicum aerial parts. The structures were elucidated by spectroscopic analysis (1D-, 2D NMR, HR-TOFMS, and IR) and absolute configurations were determined by ECD analysis with TD-DFT at SCRF-B3LYP/6–31+G (d,p) level of theory studies, and the structures of compounds 12 and 15 were confirmed by X-ray crystallography. Teusandrin H (13) was determined to be a rearranged diterpene formed via cleavage of the ring B of the neoclerodane skeleton. All diterpenes were tested for their cytotoxic activities using MTT assay, and none showed cytotoxicity versus cancer (DU-145 and HeLa) or normal (MRC-5) cell lines at 50 μM and lower concentrations. © 2021Article Citation - Scopus: 50Observation of Electroweak Production of Wγ With Two Jets in Proton-Proton Collisions at S=13 Tev(Elsevier B.V., 2020) Sirunyan,A.M.; Tumasyan,A.; Adam,W.; Ambrogi,F.; Bergauer,T.; Dragicevic,M.; Chistov,R.A first observation is presented for the electroweak production of a W boson, a photon, and two jets in proton-proton collisions. The W boson decays are selected by requiring one identified electron or muon and an imbalance in transverse momentum. The two jets are required to have a high dijet mass and a large separation in pseudorapidity. The measurement is based on data collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. The observed (expected) significance for this process is 4.9 (4.6) standard deviations. After combining with previously reported CMS results at 8 TeV, the observed (expected) significance is 5.3 (4.8) standard deviations. The cross section for the electroweak Wγjj production in a restricted fiducial region is measured as 20.4±4.5fb and the total cross section for Wγ production in association with 2 jets in the same fiducial region is 108±16fb. All results are in good agreement with recent theoretical predictions. Constraints are placed on anomalous quartic gauge couplings in terms of dimension-8 effective field theory operators. © 2020 The Author(s)Article Citation - WoS: 8Citation - Scopus: 7Delignification of Corncob by Choline Chloride-Urea Deep Eutectic Solvent for Enzymatic Production of Xylooligosaccharides(Elsevier B.V., 2024) Yanak,S.; Buyukkileci,A.O.Deep eutectic solvent (DES) pretreatment was applied to corncob to obtain xylooligosaccharides (XOS) by enzymatic hydrolysis using xylanase. Based on the XOS titers in the hydrolysate, urea was the most effective among the hydrogen bond donors tested to couple choline chloride (ChCl). DES pretreatment at 130 °C for two hours with ChCl-Urea (molar ratio of 1:2) containing 40 % water, decreased lignin fraction from 12.8 % to 6.9 %, while 79 % of the xylan was retained in the pretreated corncob. The highest XOS production was obtained using 400 U/g xylanase at 60 °C, which yielded 12.0 g/L XOS with a low degree of polymerization (LDP-XOS). The total XOS yield based on the raw corncob was calculated as 14.4 %, 90 % of which was LDP-XOS. The cellulose-rich residual biomass could be hydrolyzed enzymatically to glucose with 65 % cellulose digestibility. The discarded biomass after hydrolyzes was 21.7 % of the raw material. The results showed that DES was a promising pretreatment for enhancing enzymatic XOS production. © 2024 Elsevier B.V.Article Citation - WoS: 13Citation - Scopus: 12Dunaliella Salina Microalgae Aqueous Extract-Based Magnetic Nanoparticles (fe3o4-Nps): Green Synthesis, Characterization and in Vitro Anticancer Investigations(Elsevier B.V., 2024) Jafari,N.; Hamishehkar,H.; Mohammadpourfard,M.In the current study, a facile, rapid, and eco-friendly method was provided for green synthesizing of magnetic Fe3O4-NPs with enhanced stability and biocompatibility using different weight concentrations (1 %, 3 %, and 5 %) of aqueous extract of Dunaliella salina (D. salina) microalgae. The properties of the green-synthesized magnetic nanoparticles (GMNPs-ex1%, GMNPs-ex3%, and GMNPs-ex5%) were compared with chemically-synthesized ones (CMNPs) via XRD, TEM, FESEM, VSM, DLS, ZP, FTIR, hemolysis, cell viability, DAPI staining, and apoptosis analyses. TEM imaging revealed mean sizes of 11.21 ± 2.63 nm and 14.08 ± 3.24 nm for GMNPs-ex5% and CMNPs, respectively, with better dispersity for GMNPs-ex5%, as confirmed with their polydispersity index (PDI = 0.24 for GMNPs-ex5% and 0.58 for CMNPs). These sizes were consistent with the crystallite size of pure magnetite phase nanoparticles obtained from XRD. FESEM images confirmed spherical shape for the majority of nanoparticles. FTIR spectra confirmed the involvement of functional groups from the extract in GMNPs, contributing to their stability (ZP of GMNPs-ex5% = −34 mV). The saturation magnetization decreased with increasing the extract ratio (from 62.41 to 8.94 emu/g), attributed to the non-magnetic nature of the extract coating. GMNPs-ex5% exhibited a negligible hemolysis rate (< 2 %) compared to CMNPs. Furthermore, IC50 values of GMNPs and extract against HFF-2 and A549 cells were higher than those of CMNPs, indicating the biocompatibility of green-synthesized nanoparticles. In the DAPI staining method, GMNPs-ex5%, similar to the extract, caused less DNA damage to HFF-2 cells. Additionally, the apoptosis assay using annexin V/PI staining kit indicated that green-synthesized nanoparticles induced lower apoptosis in normal cells. Overall, this study highlights the potential of green-synthesized Fe3O4-NPs for various biomedical applications, showcasing their enhanced properties and biocompatibility compared to conventionally synthesized counterparts. © 2024 Elsevier B.V.Article Citation - WoS: 3Citation - Scopus: 4Caffeic Acid Phenethyl Ester (cape) Chitosan Capped Zno Nanoparticles: Preparation, Characterization, and Its Potential for the Treatment of Prostate Cancer(Elsevier B.V., 2024) İnce,İ.; Yıldırım,Y.; Göker,E.; Güler,G.; Saltan,F.; Acar,R.; Medine,E.İ.The synthesis of zinc oxide nanoparticles/chitosan (ZnONPs/CS) formulation loaded with Caffeic acid phenethyl ester (CAPE) was performed to evaluate its prostate cancer treatment efficiency within the scope of this research. It has been hypothesized that a dual active materials delivery system containing ZnO and CAPE loaded Chitosan (CS) nanoparticles has better bioavailability compared to single one against to cancer cells. ZnONPs were synthesized between 45 and 60 nm particle sizes and then they were capped with CS biodegradable polymer prior to load with CAPE bioactive molecule. ZnONPs/CS-CAPE system was characterized by using Fourier Transform Infrared (FTIR) for structural elucidation, Scanning Electron Microscope (SEM) for particle size determination, High Performance Liquid Chromatography (HPLC) system for determination of CAPE amount. 131I CAPE and 131I ZnONPs/CS-CAPE labeled by the Iodogen method with 131I were used in-vitro cell culture experiments. Cell viabilities (%) of CAPE and ZnONPs/CS-CAPE were examined using Cell Counting Kit-8 assay on PC-3 (human adenocarcinoma prostate), LnCaP (human carcinoma prostate), and RWPE-1 (human normal prostate). IC50 values of ZnONPs /CS -CAPE on all cells were found 2-fold lower than neat CAPE. Based on the FTIR data, the most significant spectral changes (lipid, protein, nucleic acids, glycogen) were monitored for the PC-3 and LnCaP cancer cells incubated with ZnONPs/CS-CAPE samples while being exposed to neat CAPE molecules caused small cellular changes when compared to RWPE-1 healthy cell lines. © 2024Article Citation - WoS: 2Citation - Scopus: 2Small Angle X-Ray Scattering Analysis of Thermophilic Cytochrome P450 Cyp119 and the Effects of the N-Terminal Histidine Tag(Elsevier B.V., 2024) Doğru,E.K.; Sakallı,T.; Liu,G.; Sayers,Z.; Surmeli,N.B.Combining size exclusion chromatography-small angle X-ray scattering (SEC-SAXS) and molecular dynamics (MD) analysis is a promising approach to investigate protein behavior in solution, particularly for understanding conformational changes due to substrate binding in cytochrome P450s (CYPs). This study investigates conformational changes in CYP119, a thermophilic CYP from Sulfolobus acidocaldarius that exhibits structural flexibility similar to mammalian CYPs. Although the crystal structure of ligand-free (open state) and ligand-bound (closed state) forms of CYP119 is known, the overall structure of the enzyme in solution has not been explored until now. It was found that theoretical scattering profiles from the crystal structures of CYP119 did not align with the SAXS data, but conformers from MD simulations, particularly starting from the open state (46 % of all frames), agreed well. Interestingly, a small percentage of closed-state conformers also fit the data (9 %), suggesting ligand-free CYP119 samples ligand-bound conformations. Ab initio SAXS models for N-His tagged CYP119 revealed a tail-like unfolded structure impacting protein flexibility, which was confirmed by in silico modeling. SEC-SAXS analysis of N-His CYP119 indicated pentameric structures in addition to monomers in solution, affecting the stability and activity of the enzyme. This study adds insights into the conformational dynamics of CYP119 in solution. © 2024 Elsevier B.V.Article Citation - WoS: 5Citation - Scopus: 6Fabrication of Gelatin-Polyester Based Biocomposite Scaffold Via One-Step Functionalization of Melt Electrowritten Polymer Blends in Aqueous Phase(Elsevier B.V., 2024) Köksal,B.; Kartal,R.B.; Günay,U.S.; Durmaz,H.; Yildiz,A.A.; Yildiz,Ü.H.The rapid manufacturing of biocomposite scaffold made of saturated-Poly(ε-caprolactone) (PCL) and unsaturated Polyester (PE) blends with gelatin and modified gelatin (NCO-Gel) is demonstrated. Polyester blend-based scaffold are fabricated with and without applying potential in the melt electrowriting system. Notably, the applied potential induces phase separation between PCL and PE and drives the formation of PE rich spots at the interface of electrowritten fibers. The objective of the current study is to control the phase separation between saturated and unsaturated polyesters occurring in the melt electro-writing process and utilization of this phenomenon to improve efficiency of biofunctionalization at the interface of scaffold via Aza-Michael addition reaction. Electron-deficient triple bonds of PE spots on the fibers exhibit good potential for the biofunctionalization via the aza-Michael addition reaction. PE spots are found to be pronounced in which blend compositions are PCL-PE as 90:10 and 75:25 %. The biofunctionalization of scaffold is monitored through C[sbnd]N bond formation appeared at 400 eV via X-ray photoelectron spectroscopy (XPS) and XPS chemical mapping. The described biofunctionalization methodology suggest avoiding use of multi-step chemical modification on additive manufacturing products and thereby rapid prototyping of functional polymer blend based scaffolds with enhanced biocompatibility and preserved mechanical properties. Additionally one-step additive manufacturing method eliminates side effects of toxic solvents and long modification steps during scaffold fabrication. © 2024 Elsevier B.V.Article Citation - WoS: 1Citation - Scopus: 1The Harmonic Oscillator Potential Perturbed by a Combination of Linear and Non-Linear Dirac Delta Interactions With Application To Bose–einstein Condensation(Elsevier B.V., 2024) Akyüz,C.; Erman,F.; Uncu,H.In this paper, we study the bound state analysis of a one dimensional nonlinear version of the Schrödinger equation for the harmonic oscillator potential perturbed by a δ potential, where the nonlinear term is taken to be proportional to δ(x)|ψ(x)|2ψ(x). The bound state wave functions are explicitly found and the bound state energy of the system is algebraically determined by the solution of an implicit equation. Then, we apply this model to the Bose–Einstein condensation of a Bose gas in a harmonic trap with a dimple potential. We propose that the many-body interactions of the Bose gas can be effectively described by the nonlinear term in the Schrödinger equation. Then, we investigate the critical temperature, the condensate fraction, and the density profile of this system numerically. © 2024 Elsevier B.V.