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Koleksiyondaki öğeler
- MakaleAçık Erişim2024Scopus SJRQ2RECONSTRUCTION OF POTENTIAL OF DISCONTINUOUS STURM — LIOUVILLE OPERATOR FROM SPECTRAL DATA
Akcay, O.
We deal with the inverse spectral problem of the discontinuous Sturm — Liouville operator. The aim is we to determine the potential q(x) and the boundary constant ℎ by a given spectral data. We provide the algorithm for reconstructing the potential q(x) from the spectral data.
- MakaleYalnız künye2025Scopus SJRQ2A flexible parameter estimation method for the Farlie-Gumbel-Morgenstern copula: a simulation study
Susam, Selim Orhun
This research presents a minimum distance method based on the Bernstein empirical copula process for estimating the dependence parameter of the Farlie-Gumbel-Morgenstein copula. Also, this study examines its performance through a comprehensive Monte Carlo simulation study. The findings in this paper demonstrate that selecting the optimal degree of the Bernstein empirical copula has a significant impact on the performance of the new estimation method. The proposed estimator achieves optimal performance in terms of mean squared error (MSE) for the parameter range (Formula presented.) in small sample sizes, while outside this range, its performance varies depending on the degree of the Bernstein empirical copula. Finally, we apply the new method to real data for illustrative purposes.
AtıfScopus3WoS4OpenAlex3
İncele - MakaleYalnız künye2023Scopus SJRQ1A data-driven evaluating method on the defrosting effect of the air source heat pump system in Beijing
Guo, Yanhua; Shao, Shuangquan; Geng, Xudong; Li, Hao; Wang, Zhichao; Akkurt, Nevzat
The current demand-based defrosting initiation strategies of air source heat pumps (ASHPs) faces difficulty in achieving a balance between cost and robustness. Therefore, an efficient and innovative demand-based defrosting initiation strategy is proposed in this paper, based on the learned the degradation of heating capacity (DHC) method using data-driven model. Firstly, the DHC method is developed using the initially installed sensors without additional sensors to identify the frosty state. Subsequently, the fully connected neural network (FNN) model is established for predicting frosty state using field measured data from the ASHP system. Finally, the effectiveness of the defrosting initiation strategy is further validated through practical testing. The results demonstrate that the DHC method provides a reliable database for training the FNN model, resulting in an impressive accuracy of 91.43% for predicting the frosty state in the testing set. By adopting the innovative demand-based defrosting initiation strategies, the defrosting frequency, heating loss, and power consumption are respectively decreased by 66.3%, 2.1%, and 6.0% with the SCOP enhanced by 8.6% during a heating season. The promising results highlight that the proposed strategy effectively reduces costs while ensuring the efficiency of demand-based control.
AtıfScopus23WoS22OpenAlex27İncele - MakaleAçık Erişim2025Scopus SJRQ2Evaluation effect of physicochemical properties of deep eutectic solvents on phenolic compounds extraction yield from Kultik seed
Aydin, Çağlar Mert
The aim of this study is to achieve maximum phenolic component extraction efficiency by using deep eutectic solvent, and to gain higher extraction efficiency than that obtained using conventional solvent from fruit waste, namely Kultik seed (Cucumis melo L.). Six DES (deep eutectic solvent) combination were formed using zinc chloride, ethylene glycerol, lactic acid, choline chloride, sorbitol and glucose. The evaluated DES properties were viscosity, pH, %brix and refractometric index, and their effect on phenolic extraction. Overall, the forming components significantly influence DES properties, indicating importance of choosing proper components in DES formation to receive desired extraction result. There was a correlation between extraction yield and DES properties (brix%, pH and viscosity), showing adjusting these properties are crucial in yield of desired phenolic extraction yield, r > 0.5. Alcohol based DESs had lower viscosity, higher brix% and pH in the range of 3–5. Sugar based DESs had higher viscosity, lower brix% and pH other than the range of 3–5. The highest phenolic extraction efficiency was obtained in extraction using alcohol based DESs as solvent, while the extraction using sugar and carboxylic acid based DESs underperformed. Furthermore, the extractions using some DES types (zinc chloride: ethylene glycerol (149.5 mg GAE 100 g−1), choline chloride: ethylene glycerol (161.5 mg GAE 100 g−1)) achieved better phenolic yield than that obtained using conventional solvents (water (7,6 mg GAE 100 g−1), methanol (80.2 mg GAE 100 g−1), ethanol (138.7 mg GAE 100 g−1)). These results indicate that DESs, as a green solvent, provide excellent alternative to organic solvents for green chemistry, and have a great potential to use in industrial applications involving extraction of bioactive compounds from plant sources.
- MakaleYalnız künye2024Scopus SJRQ2Insight into novel inhibitors from Sterculia urens against Cholera via pharmacoinformatics and molecular dynamics simulation approaches
Rahman, M. Oliur; Ahmed, Sheikh Sunzid; Alqahtani, Ali S.; Cakilcioğlu, Uğur; Akbar, Mohammad Ahsanul
The underdeveloped countries with large populations are facing a grave global threat in the form of cholera. Vibrio cholerae, the etiologic agent of Cholera has drawn attention recently due to antimicrobial resistance and resulting outbreaks that necessitates establishment of novel medications to counteract virulence and viability of the pathogen. Sterculia urens Roxb. (Malvaceae) is an ethnomedicinally important tree, which harbors a good number of bioactive phytocompounds. In the present study, 53 phytocompounds of S. urens were screened against the promising target ToxT of V. cholerae employing structure-based drug design approach that revealed three lead compounds, viz., 4,4,5,8-Tetramethylchroman-2-ol (−8.2 kcal/mol), Beta-Bisabolol (−8.2 kcal/mol) and Ledol (−8.7 kcal/mol) with satisfactory ADMET properties. Molecular dynamics simulation for 150 ns unveiled notable compactness and structural stability for the lead compounds considering RMSD, RMSF, Rg, MolSA, PSA and protein-ligand contacts parameters. Molecular mechanics-based MM/GBSA binding energy calculation revealed Beta-Bisabolol (−66.74 kcal/mol) to have better scores than 4,4,5,8-Tetramethylchroman-2-ol (−47.42 kcal/mol) and Ledol (−65.79 kcal/mol). Enzymes were mostly found as drug target class, and Nabilone was found as a structurally similar analog for 4,4,5,8-Tetramethylchroman-2-ol. These discoveries could aid in revealing new antibacterial medications targeting ToxT to combat Cholera. Communicated by Ramaswamy H. Sarma.
AtıfScopus8OpenAlex8
İncele - MakaleYalnız künye2024Scopus SJRQ2Effects of mutation in myostatin exon 3 on growth and carcass characteristics of Savak Akkaraman sheep
Kar, Bulent; Bahar, O.Z.; Yazdic, Ferit Can; Karaman, Altug
The myostatin gene (MSTN) is one of the main regulatory genes involved in muscle growth and development in many animals. This study aims to determine the variations in the exon 3 region associated with MSTN expression in Savak Akkaraman sheep and analyze their relationship with growth characteristics. Molecular analyses (RLFP, Real-Time PCR and DNA sequencing) were performed using DNA and RNA isolations from 70 different sheep blood and meat samples. As a result of the study, exon 3 region analysis was performed using NgomIV, AluI, DraI, HaeIII and MspI restriction endonucleases to determine the genetic diversity in Savak Akkaraman sheep breed. Two genotypes (MM and Mm) were detected for MSTN/MspI and a monomorphic mm genotype indicating the conserved exon 3 region for MSTN/HaeIII. Additionally, four new Single Nucleotide Polymorphisms (SNPs) were detected at different positions (164th, 204th, 347th, and 441th) in the working exon region. Two of these SNPs (204th T→G: isoleucine→ methionine and 347th C→A-G: proline→glutamine-arginine) caused amino acid changes. In expression studies, it was determined that MSTN gene expression was higher in female sheep than in male sheep (p<0.05). The MM genotype (MSTN/MspI) was significantly associated with increased weight gain and MSTN expression, while TT genotype at SNP 204 and GG genotype at SNP 347 was found to be associated with meat yield and growth traits (p<0.05). As a result, the genetic differences and functional effects of the new genotypes determined in this study may shed light on breeding strategies aiming to increase meat production.
AtıfScopus3WoS3OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ2Seismic Resistance and Performance Evaluation of Masonry Dwellings After the February 6, 2023, Kahramanmaraş Earthquake Sequence in Türkiye
Onat, Onur; Yön, Burak; Uslu, Ali; Öncü, Mehmet Emin; Varolgüneş, Sadlk; Karaşin, I.B.; Gör, Mesut
On February 6, 2023, two catastrophic earthquakes occurred on the East Anatolian Fault. The earthquakes had magnitudes of Mw = 7.7 and 7.6 and struck Kahramanmaraş-Pazarclk and Kahramanmaraş-Elbistan, respectively. The Kahramanmaraş-Pazarclk earthquake was triggered at 04:17 local time on the Dead Sea Fault (a branch of the East Anatolian Fault). The last earthquake on the addressed fault occurred about 500 years ago. The recorded peak ground acceleration (PGA) at the Pazarclk station reached 2.05g. In addition, the Pazarclk earthquake triggered two independent earthquakes, the Nurdaǧl and Islahiye earthquakes, which occurred 10 min later than the Pazarclk earthquake. However, the last earthquake, with its epicenter in Kahramanmaraş-Elbistan, struck at 13:24 local time. The recorded PGA for the Elbistan earthquake is 0.68g. This study aims to present the fault rupture mechanism of the February 6, 2023, Kahramanmaraş earthquakes, earthquake characteristics, and to evaluate the performance of masonry dwellings during the Kahramanmaraş earthquake doublet, which affected 10 provinces and numerous towns and villages. This paper also aims to illustrate the damage and failure mechanisms of the masonry dwellings, despite unexpectedly high accelerations that exceeded the design spectrum in the field, specifically in Kahramanmaraş, Gaziantep, Hatay, and Malatya, according to the current earthquake code in use.
AtıfScopus16OpenAlex22İncele - MakaleAçık Erişim2024Scopus SJRQ2Titanium alloys: A closer-look at mechanical, gamma-ray, neutron, and transmission properties of different grade alloys through MCNPcode application
ALMisned, Ghada; Guler, Omer; Sen Baykal, Duygu; Kilic, G.; Tekin, H.O.
Titanium alloys play a vital role in optimizing the effectiveness and security of nuclear reactors, strengthening structural durability, and facilitating the effective handling of nuclear waste. The aim of this study is to investigate the gamma-ray, neutron, and transmission properties of four common titanium alloys through the examination of the deposited energy amount in the liquid sodium coolant material, in relation to the mechanical properties of these alloys. MCNP (version 6.3) is utilized for designing the titanium pipes. Next, the pipes were re-designed considering the elemental mass fractions and densities of the investigated titanium alloys. Grade 26 sample is reported with the highest values of mass attenuation coefficients and the lowest HVL values among those investigated alloys. Grade 26 is reported to have the lowest TF value, whereas Grade 12 demonstrated the highest TF value. The highest Effective Removal Cross Section (ΣR, 1/cm) value against fast neutrons is reported for Grade 26. The utilization of Grade 26 sample as pipe material resulted in the lowest deposited energy amount (MeV/g) and subsequent lowest contamination in the coolant material. Out of the alloys that were chosen for analysis, it has been determined that Grade 26 exhibits the highest level of strength. It can be concluded that the Grade 26 alloy exhibits desirable characteristics for applications in nuclear technologies that require superior gamma-ray and neutron absorption properties, as well as exceptional mechanical properties. Nevertheless, it is essential to emphasize the importance for ongoing studies to enhance the existing material properties of Grade 26, with the aim of achieving improved safety and efficacy in nuclear applications.
AtıfScopus11OpenAlex11İncele - MakaleAçık Erişim2025Scopus SJRQ3“Social Relations between the Sexes in Athena Farrokhzad’s Morals According to Medea”
Özger, Pelin Doğan
This paper explores how patriarchal power relations construct the idea of “nature” in Athena Farrokhzad’s Morals According to Medea (Moral enligt Medea, 2022), an adaptation of Euripides’ classic play Medea (431 BCE). The analysis will concentrate on Medea’s subversion of patriarchal “appropriation” tactics from a feminist perspective, particularly through ideological codes embedded in the dialogues between Medea and Morality, the only other character in the play. By doing so, it seeks to understand women’s position in relation to patriarchy through a materialist feminist lens, with particular attention to the conflict between Medea and Morality. The focus will also be on how Medea challenges traditional discourses of motherhood, constructed within male-dominated societal structures. The study will further discuss the ways in which she raises her voice in resistance, both as a local and as a refugee, within the spaces where she is either confined or expelled. The discussion will be framed within the context of the theory of social relations between the sexes highlighting the specific impact of women’s resistance and militancy in examining the mechanisms of sovereignty.
- MakaleYalnız künye2024Scopus SJRQ1Assessment of short and long-term pozzolanic activity of natural pozzolans using machine learning approaches
Khatti, Jitendra; Polat, Berivan Yılmazer
This investigation introduces the optimal performance models for predicting the compressive strength (CS) and pozzolanic activity index (PAI) by comparing the machine learning models. The machine learning models, i.e., multilinear regression (MLR), support vector machine (SVM), gaussian process regression (GPR), decision tree (DT), random forest (RF), and gene expression programming (GEP) have been trained (TRN) and tested (TST) by 28 and 7 data points. For the first time, the SiO2, Al2O3, Fe2O3, SiO2 +Al2O3 +Fe2O3, reactive SiO2, Blaine specific surface area, and specific gravity have been used as input variables to compute the CS, and 28 days PAI (28PAI), and 90 days PAI (90PAI) of the natural pozzolans. The multicollinearity analysis showed the SiO2, Al2O3, Fe2O3, SiO2 +Al2O3 +Fe2O3, reactive SiO2, and specific gravity have problematic multicollinearity (variance inflation factor – VIF > 10). Therefore, the root mean square error (RMSE), mean absolute error (MAE), correlation coefficient (R), performance index (PI), and variance accounted for (VAF) metrics have been implemented to evaluate the model's performance and multicollinearity impact. From the comparison of models, it has been recorded that model GPR outperformed the MLR, SVM, DT, RF, and GEP models in predicting CS (PI = 1.29, VAF = 71.31, R = 0.8473, MAE = 0.9390 MPa), 28PAI (PI = 1.87, VAF = 94.88, R = 0.9744, MAE = 0.7295 %), and 90PAI (PI = 1.72, VAF = 88.11, R = 0.9393, MAE = 1.2444 %) in the TST phase, close to ideal values. The score, generalizability. Wilcoxon test, uncertainty analysis, Anderson-daring test, and accuracy metrics have confirmed the superiority of GPR models in predicting CS, 28PAI, and 90PAI of natural pozzolans.
AtıfScopus28WoS25OpenAlex28İncele - MakaleAçık Erişim2021Scopus SJRQ1Assessment of potential health risk associated with the use of Cladophora fracta as mulch
Öbek, Erdal; Topal, E. Işıl Arslan; Topal, Murat
In this study, cadmium, copper, nickel, zinc, chromium, manganese and lead were determined in Cladophora fracta present in Lake Hazar (Turkey). The health risks (non-carcinogenic and carcinogenic) of heavy metals associated with the use of Cladophora fracta as mulch were also determined. Bioconcentration factor (BCF) and metal pollution index (MPI) were calculated. When compared with reference value (1.5 mg/kg for Cr and 200 mg/kg for Mn), the highest accumulation by Cladophora fracta was seen in the month of June as 1442 ± 7.2% (23.13 mg/kg) for Cr and the lowest accumulation calculated in the month of July as 5 ± 0.2% (210 mg/kg) for Mn. In our study, the highest MPI value was 13.69 in September. The magnitude of MPI values of heavy metals determined during April to September appeared in the following order September > August > July > June > May > April. The HQing (hazard quotient due to ingestion) and HQinh (hazard quotient due to inhalation) in all months were chidren > female > male while the order of HQder (hazard quotient due to dermal) was determined as male > female > children. Non-carcinogenic risk (HQ) and Hazard Index (HI) values in terms of ingestion, inhalation and dermal ways were lower than 1. Also, total HI values were < 1. As a result, there was not non-carcinogenic and carcinogenic risks associated with usage of Cladophora fracta as mulch.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2021Scopus SJRQ1A scaling procedure for straightforward computation of sorptivity
Lassabatere, Laurent; Peyneau, Pierre-Emmanuel; Yilmaz, Deniz; Pollacco, Joseph; Fernández-Gálvez, Jesús; Latorre, Borja; Moret-Fernández, David; Di Prima, Simone; Rahmati, Mehdi; Stewart, Ryan D.
Sorptivity is a parameter of primary importance in the study of unsaturated flow in soils. This hydraulic parameter is required to model water infiltration into vertical soil profiles. Sorptivity can be directly estimated from the soil hydraulic functions (water retention and hydraulic conductivity curves), using the integral formulation of . However, calculating sorptivity in this manner requires the prior determination of the soil hydraulic diffusivity and its numerical integration between initial and final saturation degrees, which may be difficult in some situations (e.g., coarse soil with diffusivity functions that are quasi-infinite close to saturation). In this paper, we present a procedure to compute sorptivity using a scaling parameter, cp, that corresponds to the sorptivity of a unit soil (i.e., unit values for all parameters and zero residual water content) that is utterly dry at the initial state and saturated at the final state. The cp parameter was computed numerically and analytically for five hydraulic models: Delta (i.e., Green and Ampt), Brooks and Corey, van Genuchten-Mualem, van Genuchten-Burdine, and Kosugi. Based on the results, we proposed brand new analytical expressions for some of the models and validated previous formulations for the other models. We also tabulated the output values so that they can easily be used to determine the actual sorptivity value for any case. At the same time, our numerical results showed that the relation between cp and the hydraulic shape parameters strongly depends on the chosen model. These results highlight the need for careful selection of the proper model for the description of the water retention and hydraulic conductivity functions when estimating sorptivity.
AtıfScopus14OpenAlex17İncele - MakaleYalnız künye2024Scopus SJRQ2On β-titanium alloys: tailoring gamma-ray, and neutron transmission properties for nuclear and biomedical applications
Almisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Güler, Ömer; Kilic, Gokhan; Mesbahi, Asghar; Tekin, Huseyin Ozan
This study explores the gamma-ray and neutron transmission properties of β-Titanium alloys pivotal for their performance in nuclear and biomedical applications. Utilizing the Monte Carlo N-Particle (MCNP 6.3) simulations, we analyzed a spectrum of Ti-based alloys modified with elements like molybdenum (Mo), zirconium (Zr), niobium (Nb), and hafnium (Hf) to determine their radiation attenuation properties. Key parameters such as mass and linear attenuation coefficients, half-value layers, exposure buildup factors, and fast neutron effective removal cross-section values were computed, revealing significant enhancements in attenuation with the addition of high-Z elements. Specifically, alloys like Ti50Hf50 and (TiZr)40Cu60 exhibited superior photon and fast neutron attenuation due to their high-Z constituents. For instance, Ti50Hf50 showed a mass attenuation coefficient of 0.217 cm2/g and a half-value layer of 2.97-cm at 0.1 MeV photon energy, while (TiZr)40Cu60 demonstrated similar performance with a mass attenuation coefficient of 0.198 cm2/g and a half-value layer of 3.26-cm. These alloys also exhibited effective neutron removal cross-section values of 0.115 cm-1 and 0.130 cm-1, respectively. Alloys with lower-Z elements showed less attenuation, which may be beneficial in scenarios requiring reduced radiographic contrast in biomedical applications. The MCNP outcomes were in strong agreement with standard data, affirming the accuracy of computational methods in predicting material behavior. In conclusion, tailored alloy development is crucial for improving radiation shielding and diagnostic visualization, with broader implications for patient safety and treatment efficacy.
AtıfScopus3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Recycling Ti1.0Nb0.3Ta0.07Zr0.05 Conventional Alloys: Production of Non-equimolar TiZrCrNb0.3Ta0.07 Medium Entropy Alloys with the Addition of Cr for Improved In Vitro Corrosion Resistance
Guler, Omer; Say, Yakup; Dikici, Burak; Ozkul, Iskender; Niinomi, Mitsuo
A non-equimolar TiZrCrNb0.3Ta0.07 medium entropy alloy (MEA) was successfully designed as theoretical and produced by arc-melting method from Ti1.0Nb0.3Ta0.07Zr0.05 (TNTZ) scraps for possible usage in biomedical applications in this study. The main aim of this study is to find an alternative way to recycle with a reduced carbon footprint the available TNTZ conventional alloy and convert it to a value-added product during this recycling such as medium entropy alloys (MEAs) via using less energy. To examine the microstructural changes induced by the annealing process, scanning electron microscopy was employed. The chemical composition of the HEAs was assessed using energy-dispersive spectroscopy and x-ray photoelectron spectroscopy. Additionally, x-ray diffraction analysis was used to determine the crystallographic structure and phase composition of HEAs. Furthermore, in order to evaluate the electrochemical corrosion performance of the alloys, comprehensive in vitro corrosion tests were conducted in a simulated body fluid solution, specifically Hanks's Balanced Salt Solution. Some elemental segregation has been observed after the annealing process. A big migration of Zr and Cr elements was observed in the samples from the interdendritic region to the dendritic area during the annealing process. This segregation resulted in approximately 1.4 times increase in the hardness of the MEA. The electrochemical corrosion results showed that the in vitro resistance of the MEAs was higher than that of its conventional scraps.
AtıfScopus5OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ1A Novel Secure S-box Design Methodology Based on FPGA and SHA-256 Hash Algorithm for Block Cipher Algorithms
Aydin, Yilmaz; Garipcan, Ali Murat; Özkaynak, Fatih
In this study, a novel robust design methodology that successfully meets the performance and security criteria for substitution-boxes (s-boxes), critical component in block cipher systems, is proposed. Unlike traditional methods providing low-level randomness, the proposed method utilizes physical true randomness as the entropy source, significantly improving the robustness and effectiveness of the s-box design. Phase noise (jitter) occurring on ring oscillators (ROs) is used for true randomness inputs with high security and unpredictability properties in the proposed method. The success of the proposed method is evaluated by considering key performance metrics of s-boxes such as bijectivity, strict avalanche criterion (SAC), bit independence criterion (BIC), nonlinearity (NL), and differential probability (DP). In the novel method, including the integration of the secure hashing algorithm (SHA)-256 hash function for cryptographic usage adequacy of the noise signal, 106.75 NL, 0.4995 SAC, and 105.7 average BIC-NL values can be obtained for s-boxes without any additional optimization process. Considering the low DP value, the analysis results confirm that the s-boxes produced by the proposed method can provide remarkable resistance against linear and differential cryptanalysis scenarios. Numerical findings also show that the proposed s-boxes are competitive and superior compared to other s-box designs in the literature. In conclusion, we believe that the methodology producing robust and reliable s-box solutions for block cipher systems contains important contributions inspiring future research regarding design principles.
AtıfScopus23WoS27OpenAlex20İncele - MakaleYalnız künye2024Scopus SJRQ3Powder coating waste filler in high-density polyethylene – Variations in morphology, mechanical and thermal performance; [Variationen in Morphologie, mechanischer und thermischer Leistung von Pulverlackrecyclaten als Füllstoff in Polyethylen mit hoher Dichte]
Kısmet, Y.
In the present study, electrostatic powder coating waste was recycled and employed to reinforce high-density polyethylene. The hydrolysis method was preferred to modify the powder coating waste of various systems, and they were mixed with high-density polyethylene at various weight ratios. The mixtures were prepared in a mechanical mixer and then in an extruder to obtain a homogeneous mixture. This homogeneous structure was pressed into molds with a plastic injection device to obtain standard tensile samples. Mechanical and thermal tests were conducted on the samples. It was determined that the tensile stress of the sample decreased with the increase in filler content. The changes in sample tensile strength were investigated after the samples were aged. Three-point bending strength of the samples was also investigated and it was observed that they became more resistant to vertical loads as the filler content increased. The Izod impact strength of the samples differed based on the filler type and weight ratio. Furthermore, mass loss in the produced mixtures was determined with thermogravimetric analysis. The matrix and filler bonding mechanisms were observed under an electron microscope.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ1Radiation shielding properties of composites of TiZrNbHfTa refractory high entropy alloy reinforced with TiZrNbHfTaOx high-entropy oxide
Güler, Ömer; Yılmaz, Demet; Kanca, M. Sait; Edalati, Kaveh; Taşgın, Yahya
Radiation shielding materials play a critical role in advancing the next generation of nuclear reactors. Among these, high-entropy materials with refractory properties emerge as a new category for radiation shielding applications. This study introduces TiZrNbHfTa-TiZrNbHfTaOx composites tailored for such purposes. Initially, a TiZrNbHfTa refractory high-entropy alloy (RHEA) is synthesized via mechanical alloying, followed by the oxidation of the alloy to obtain its refractory high-entropy oxide (RHEO), TiZrNbHfTaOx. Composites are then prepared by blending 5%, 10%, and 20% weight fractions of RHEO with RHEA using mechanical alloying. Comparative analysis of shielding properties reveals a decrease in mass attenuation coefficient and effective atomic number with increasing RHEO content. While RHEA exhibits superior shielding performance against gamma photons and neutrons, the composite containing 20% RHEO emerges as the optimal shield against alpha and proton irradiations. The equivalent neutron dose rate and removal cross-section values are obtained 49.8% and 0.142 for the composite with 20% RHEO, respectively. These findings, supported by computational simulations in this study, contribute valuable insights for the advancement of novel shielding materials crucial for future nuclear reactor technologies.
AtıfScopus24WoS22OpenAlex24İncele - MakaleAçık Erişim2025Scopus SJRQ2Geochronological and isotopic data from the adakitic Dodurga Pluton (Central Pontides, N Türkiye): new insights for the geodynamic evolution of the northern Neotethys
Çimen, Okay; Gücer, Mehmet Ali; Simonetti, Antonio; Karaoğlan, Fatih
The Dodurga Pluton is located within the Central Pontides (northern Türkiye), has a SW–NE elongation, and consists of granodiorite and dacite porphyry. Previous studies have suggested that this pluton is Triassic in age, and its whole-rock geochemical systematics is consistent with that from adakitic magmatic occurrences rather than the classic arc granitoid suite. This study reports for the first time in situ/whole-rock radiogenic isotopic (Sr, Nd, and Pb) and mica/amphibole Ar–Ar age data to evaluate better its petrogenetic/geodynamic evolution and the chemical nature of mantle source(s). Unlike previous data, combined new in situ zircon U–Pb yield Late Cretaceous crystallization ages of 84.2 ± 0.9 Ma and 86.9 ± 0.9 Ma, and the Ar–Ar age data along with apatite fission track measurements suggest magma cooling extending to 82.3 ± 0.4 Ma and 85.4 ± 0.4 Ma, respectively. The apatite fission track (AFT) dating results also reveal that this pluton was buried at a depth of 2.5–3 km following a fast-cooling period during the Late Cretaceous and cooled/exhumed over ~2 km during the Middle–Late Miocene (15–10 Ma) in a slow cooling phase. The overall data reported here suggest that the Dodurga Pluton represents melts derived from an enriched/metasomatized mantle source that interacted with lower crustal mafic rocks in an active continental margin as a result of northward subduction of the northern branch of the Neotethys Ocean.
- MakaleYalnız künye2023Scopus SJRQ2Investigation of Antimicrobial, Anti-Quorum Sensing, and Cytotoxic Activities of Flavonoids Isolated from Pulicaria armena Boiss. & Kotschy ex Boiss. (Asteraceae)
Başpınar, Yasemin; Gürbüz, Perihan; Dilem Doğan, Şengül; Gözde Gündüz, Miyase; Aleksic, Ivana; Vojnovic, Sandra; Nikodinovic-Runic, Jasmina; Yavuz Paksoy, Mehmet
This is the first report on the separation and biological assessment of all metabolites derived from Pulicaria armena (Asteraceae) which is an endemic species narrowly distributed in the eastern part of Turkey. The phytochemical analysis of P. armena resulted in the identification of one simple phenolic glucoside together with eight flavon and flavonol derivatives whose chemical structures were elucidated by NMR experiments and by the comparison of the spectral data with the relevant literature. The screening of all molecules for their antimicrobial, anti-quorum sensing, and cytotoxic activities revealed the biological potential of some of the isolated compounds. Additionally, quorum sensing inhibitory activity of quercetagetin 5,7,3’ trimethyl ether was supported by molecular docking studies in the active site of LasR which is the primary regulator of this cell-to-cell communication system in bacteria. Lastly, the critical molecular properties indicating drug-likeness of the compounds isolated from P. armena were predicted. As microbial infections can be a serious problem for cancer patients with compromised immune systems, this comprehensive phytochemical research on P. armena with its anti-quorum sensing and cytotoxic compounds can provide a new approach to the treatment.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ1Novel formulations ameliorate osteoarthritis in rats by inhibiting inflammation and oxidative stress
Erten, Fusun; Ozdemir, Oguzhan; Tokmak, Muhammed; Durmus, Ali Said; Ozercan, Ibrahim Hanifi; Morde, Abhijeet; Padigaru, Muralidhara; Sahin, Kazim
The study tested new oral plant-based formulations (F) on rats with monosodium iodoacetate (MIA)-induced osteoarthritis, measuring inflammation, antioxidant levels, paw size, stride, and analyzing knee joint images. Fifty-six female Sprague Dawley rats were allocated into 8 groups: (1) Control, (2) MIA (OA induced with MIA), (3) MIA + F1 [curcuminoids+gingerols+acetyl-11-keto-β boswellic acid (AKBA)], (4) MIA + F2 (curcuminoids+Withania glycosides+AKBA), (5) MIA + F3 (curcuminoids+total withanolides+AKBA), (6) MIA + F4 (curcuminoids, AKBA), (7) MIA + UCII (type II collagen), and (8) MIA + GCHON (Glucosamine Chondroitin). Treatments F1 to F4 reduced right joint diameter and improved stride length and paw area in OA rats. Despite improvements with treatments F1 to F4, there was no significant difference between these groups (p >.05). In OA animals, F1 to F4 treatments decreased MDA levels and increased antioxidant enzymes activities (p <.001). This was done by reducing levels of inflammatory markers and enzymes like IL-1β, IL-6, MMP-8, TNF-α, CRP, COMP, and LOX-5, while increasing the anti-inflammatory cytokine IL-10. In conclusion, these plant-based treatments significantly reduced osteoarthritis severity, slowed disease progression by reducing inflammation, and protected joints from damage, showing a protective effect in rats with induced osteoarthritis, likely due to their anti-inflammatory and antioxidant properties.
AtıfScopus14WoS11OpenAlex10İncele
