Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Akkurt, Nevzat(24)
- Gul, Muhammet(11)
- Yucesan, Melih(9)
- Alataş, Mevlüt(8)
- Aslan, Naim(8)
- Batan, Nevzat(8)
- Ezer, Tülay(8)
- Utku, Anıl(8)
- Erata, Hüseyin(7)
- Xu, Qian(7)
- Dal, Murat(6)
- Etli, Serkan(6)
- Konurhan, Zekeriya(6)
- Topal, Murat(6)
- Yeşiltepe, Akgün(6)
- Yüksekol, Özlem Doğan(6)
- Şahal, Hakan(6)
- Şahin, Aykut(6)
- Cihangir, Salih(5)
- Ding, Yulong(5)
- Işık, Erdem(5)
- Kaya, Sema Kayapinar(5)
- Kök, Mediha(5)
- Orhan, Cemal(5)
- Sengur, Abdulkadir(5)
- Serdar, Osman(5)
- Uyan, Umut(5)
- Zengin, Gokhan(5)
- Öbek, Erdal(5)
- Aslan, N.(4)
- Baltacı, Nazlı(4)
- Baş, Kazım(4)
- Başkutlu, Salih(4)
- Boyali, Handan(4)
- Eldin, Sayed M.(4)
- Erdemoğlu, Murat(4)
- Erten, Fusun(4)
- Gürler, Nedim(4)
- Hudaverdi, Burcu(4)
- Kanca, Muhammed Sait(4)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ1Analysis of unsteady thermo-solutal MoS2-EO Brinkman electro-conductive reactive nanofluid transport in a hybrid rotating Hall MHD generator
Shamshuddin, M.D.; Bég, O. Anwar; Akkurt, Nevzat; Leonard, Henry J.; Bég, Tasveer A.
MHD rotating generators offer a plausible renewable energy mechanism. New designs are emerging in which nanotechnology is contributing. Such systems are increasingly deploying more complex functional fluid materials such as base fluids containing magnetic nanoparticles which constitute electromagnetic nanofluids and can be tuned to enhance efficiencies. Motivated by these developments, a mathematical model is presented for the combined effects of Hall current, heat source, chemical reaction and radiative flux on the unsteady rotating thermo-solutal magnetohydrodynamic transport of a Molybdenum disulphide (MoS 2)-EO oil electroconductive Brinkman nanofluid to study the boundary layer characteristics in the vicinity of the side wall of an MHD generator system. The governing dimensional conservation equations are scaled using appropriate transformations into a system of dimensionless coupled partial differential equations. Under appropriate initial and boundary conditions, solutions are derived using the Laplace Transform Method (LTM) and complex variables. The physical impacts of the magnetic, nanoscale, thermal and species control parameters on primary and secondary velocity, temperature and concentration are visualized graphically. The judicious doping of the base fluid with MoS 2 nanoparticles is shown to achieve superior thermal performance for MHD rotating energy generators.
AtıfScopus38OpenAlex24
İncele - MakaleAçık Erişim2023Scopus SJRQ3Production of SBS Reinforced Polyester Composite: Characterization of Physical and Chemical Properties
Şahal, Hakan; Aydoğmuş, Ercan
In this study, dissolved styrene butadiene styrene (SBS) copolymer is homogeneously reinforced into orthophthalic unsaturated polyester (UP) resin. Polyester composite production is carried out with the help of methyl ethyl ketone peroxide (MEKP) and cobalt octoate (Co Oc) catalysts. The density, Shore D hardness, thermal conductivity coefficient, thermal stability, morphological surface structure, and chemical bond structure of the obtained composite have been examined. According to the results, SBS reinforcement decreases the density of the composite and increases the thermal conductivity coefficient. The addition of SBS at different weight ratios (1%, 3%, 5%, 7%, and 10% w/w) reduces both the hardness and thermal stability of the polyester composite. According to the test and analysis results, 5 wt.% SBS reinforced polyester composite production is determined as the optimum ratio. 7 wt.% and above SBS reinforcement negatively affect the physical and chemical properties of the obtained composite. For example, when 10 wt. % SBS reinforced composite is examined by scanning electron microscope (SEM), and irregular pores are observed in the surface morphology. Also, it is understood by Fourier transform infrared spectroscopy (FTIR) that there is a physical interaction between SBS and polyester and that no chemical bond is formed. The thermal decomposition behavior of the composite has been determined according to the decrease in the activation energy. As SBS ratio increases, it is understood that the thermal stability of the product obtained with the decrease in the activation energy of the polyester composite weakens.
AtıfScopus2
İncele - MakaleAçık Erişim2023Scopus SJRQ1Lutein/Zeaxanthin Isomers and Quercetagetin Combination Safeguards the Retina from Photo-Oxidative Damage by Modulating Neuroplasticity Markers and the Nrf2 Pathway
Sahin, Emre; Orhan, Cemal; Sahin, Nurhan; Padigaru, Muralidhara; Morde, Abhijeet; Lal, Mohan; Dhavan, Nanasaheb; Erten, Fusun; Bilgic, Ahmet Alp; Ozercan, Ibrahim Hanifi
Exposure to light-emitting diode (LED) light is a primary cause of retinal damage, resulting in vision loss. Several plant-derived substances, such as lutein and quercetagetin (QCG), show promise in supporting eye health. In this study, the impact of lutein/zeaxanthin (L/Z, Lutemax 2020) and QCG were evaluated individually and together in a rat model of LED-induced retinal damage. A total of 63 Wistar rats were allocated into nine groups (n = 7). For 28 days, the rats received L/Z (10 or 20 mg/kg BW), quercetin (QC, 20 mg/kg BW), QCG (10 or 20 mg/kg BW), or a mixture of different lutein and QCG dosages, after which they were exposed to LED light for 48 h. LED exposure led to a spike in serum malondialdehyde (MDA) and inflammatory cytokines, as well as an increase in retinal NF-κB, ICAM, GFAP, and MCP-1 levels (p < 0.0001 for all). It also reduced serum antioxidant enzyme activities and retinal Nrf2, HO-1, GAP43, NCAM, and outer nuclear layer (ONL) thickness (p < 0.0001 for all). However, administering L/Z and QCG, particularly a 1:1 combination of L/Z and QCG at 20 mg/kg, effectively reversed these changes. The treatment suppressed NF-κB, ICAM, GFAP, and MCP-1 while enhancing Nrf2, HO-1, GAP43, and NCAM and preventing ONL thickness reduction in LED-induced retinal damage rats. In conclusion, while LED light exposure caused retinal damage, treatment with L/Z, QC, and QCG, particularly a combined L/Z and QCG regimen, exhibited protective effects on the retina. This is possibly due to the modulation of neuroplasticity markers and nuclear transcription factors in the rats’ retinal cells.
AtıfScopus22OpenAlex22
İncele - MakaleAçık Erişim2023Scopus SJRQ4New Approaches to Predict the Sperm Quality by the Spermatozoal miRNA Content in Fish: A Review
Kocabaş, Filiz Kutluyer; Kocabaş, Mehmet
The survival of the progeny and fertilization success depend on high-quality mature spermatozoa containing DNA and coding and non-coding RNAs besides the female gamete quality. Sperm cells and gonads in fish contain different RNA classes. It is possible that the development of fish could be affected by miRNA and/or other non-coding RNAs being abundant in Teleost fish and having important functions. Studies about the presence of miRNA in some fish species (e.g. Danio rerio, Salmo salar, Carassius auratus, Cyprinus carpio) showed that sperm motility is regulated by miRNA. Nevertheless, limited knowledge and several hypotheses have been presented about classes and content of RNAs in fish spermatozoa. More research about the effects of miRNA on fish reproduction and sperm quality are needed for population, aquatic ecosystems, and broodstock management, and the evaluation of molecular sperm quality parameters with miRNA could be used together with traditional techniques.
AtıfScopus4İncele - MakaleYalnız künye2023Scopus SJRQ2Novel electrochemical sensor of nebivolol drug used for treatment of hypertension and chronic heart failure
İpek, Yeliz; Koçak, Berna
Nebivolol is a beta-blocker used to treat high blood pressure and heart failure. Nebivolol is a cardiovascular drug in the group of selective beta-blockers (with selective action on the cardiovascular system). It prevents the increase in heart rate and controls the pumping power of the heart. It also has a dilating effect on blood vessels and helps to lower blood pressure with this effect. The ability to analyze nebivolol quickly, simply, economically and reliably is of high importance in two cases. The first is to adjust the drug dosage to be used by the patients, and the second is to provide fast intervention in the drug production process as a result of fast and accurate quality control in drug production and to provide quality control of produced tablets. Since, the boric acid has a good catalytic activity and enhances the peak current intensity, a boric acid‒glutardialdehyde-modified glassy carbon electrode was designed for investigation of electrochemical behavior and quantitative determination of nebivolol (NBV) in this study. Electrochemical reaction peak and the peak current intensity changes with changing NBV concentration provide detection of NBV. The role of glutardialdehyde was to immobilize the boric acid on the electrode surface with its crosslinking ability. The designed electrode was achieved by dropping boric acid‒glutardialdehyde mixture on glassy carbon electrode and drying it at room conditions. By using boric acid‒glutardialdehyde-modified glassy carbon electrode (BA‒GA2/GCE), quantitative analysis of the active drug ingredient (NBV), which is widely used in the treatment of hypertension and chronic heart failure, was carried out sensitively, selectively and at low detection limits with low cost. This electrode exhibited good repeatability and stability for detection of the oxidation peak of NBV. In addition, the working ranges and detection limits of NBV were determined in the optimum experimental conditions. SWV technique was used and according to the results obtained, LOD values for NBV in BR buffer (pH 9) and in urine samples were 1.0 × 10−7 mol L−1 and 4.12 × 10−7 mol L−1, respectively. The feasibility of the developed novel sensor was demonstrated by performing recovery studies with tablet and urine samples containing NBV. The recovery results were 93.10% and 58.16% for urine and tablet samples, respectively. Graphical abstract: [Figure not available: see fulltext.]
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3Mapping Tendencies in Curriculum Research on Physical Education and Sports: A Bibliometric Analysis
Şahin, Aykut; Karakaya, Yunus Emre; Dikmen, Melih
This study aims to investigate previous curriculum research on physical education and sports using the bibliometric mapping method. A systematic map was created for the research tendencies in physical education and sports curricula studies conducted between 1975 and 2021. Accordingly, the intention is to fill a gap in the literature by conducting a general situation analysis about the present status of curriculum studies in physical education and sports based on the publication and citation data obtained from the Web of Science (WoS) database. The software VOSviewer was utilised for the bibliometric analysis. After scanning the studies in the database, 454 studies were accessed at the initial stage. A total of 114 studies were covered in the analysis by following certain exclusion criteria. The findings suggested that curriculum studies in physical education and sports were conducted in association with numerous multidisciplinary research areas. Furthermore, in recent years, a linear increase in curriculum studies has occurred on this subject matter. It was also found that scientists from universities in the United States of America were at the centre of the studies. Another striking result was the limited number of journals specialising in sports and education. The results of the bibliometric maps also demonstrated that the researchers in this field investigated a variety of subjects that can be grouped under four main disciplines: ‘health and physical education,’ ‘curriculum reform,’ ‘contents,’ and ‘pre-service teachers.’ Addedl the results revealed that studies on physical education and sports curricula were conducted with a focus on current developments.
AtıfScopus3OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ4Individual and Combined Toxicity of Polycyclic Aromatic Hydrocarbons Phenanthrene and Fluoranthene in Freshwater Amphipod Gammarus pulex (L., 1758) (Amphipoda: Gammaridae)
Yildirim, Nuran Cikcikoglu; Serdar, Osman; Derman, Taner
The combined toxicity of polycyclic aromatic hydrocarbons on freshwater amphipod Gammarus pulex was investigated. The 14-day LC50 values of fluoranthene, phenanthrene and their combination for G. pulex were determined as 5.88±0.23, 8.31±0.57 and 7.00±0.33 mg/L, respectively. To evaluate the single and combined toxicity, sublethal concentrations of fluoranthene, phenanthrene and their combination were exposed to G. pulex for 14 days. Acetylcholinesterase, glutathione-s-transferase and cytochrome P450 1A1 enzymes were measured as biomarkers. Acetylcholinesterase activities showed significant inhibition at the end of 7 and 14 days. No statistically significant change was observed in cytochrome P450 1A1 levels at the end of the 7th day, but a significant increase was detected at the end of the 14th day. A significant inhibition was observed in glutathione-s-transferase activities at the end of the 7th and 14th days. Statistically significant changes were observed in all parameters when the application times are compared. It was determined that G. pulex exposed to different concentrations of phenanthrene and fluoranthene individually and in combination caused significant changes in activites of the all measured enzymes. It was concluded that the cytochrome P450 1A1, glutathione-s-transferase and acetylcholinesterase enzymes in G. pulex are useful biochemical markers for the determination of polycyclic aromatic hydrocarbon toxicity.
AtıfScopus3İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of metal pollution related to human health risk in freshwater snail Viviparus contectus (Millet, 1813) as a potential bioindicator species in Lake Habitat (Turkey)
Kutluyer Kocabaş, Filiz; Göktürk Aksu, Emsiye; Kocabaş, Mehmet
Freshwater mollusks are employed as bioindicators for the assessment of water quality in biomonitoring studies since the water quality of natural resources is crucial for humans. The freshwater snail species known as Viviparus contectus (Viviparidae: Gastropoda) is one that people eat. Here, the levels of heavy metals (Cd, Cr, Pb, As, Zn, and Cu) in water and V. contectus samples were determined. An Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES, Spectro Arcos, vertical plasma) was used for the analysing the heavy metal concentrations in water and freshwater snail samples. The results of the current investigation demonstrated that freshwater snails accumulated metals in their water and soft tissues in the following orders: Pb > Cr = Zn = Cu = Cd = As and Zn > Cu > Pb > Cd > As = Cr. Autumn was the time of year when higher amounts of heavy metals (As, Cr, Cu, Zn, and Hg) were found. Pb content in the freshwater snail samples was strongly impacted by seasonal fluctuations (P 0.05). For adults, the EDI (estimated daily intake) values were lower than the TDI (tolerable daily intake) values, and the HI (hazard index) values were below 1. Freshwater snail samples had Zn and Pb levels that were over the FAO/WHO, Turkish Food Codex, JECFA, and EC limit values. Except for Pb, the water study shows mean metal concentrations below the USEPA, Turkish Pollution Control Regulation, and World Health Organisation maximum allowed levels. Aquatic ecosystems were negatively impacted by anthropogenic activities overall, and this study can provide a helpful data set for investigations on metallic contamination in water bodies and biomonitoring in freshwater ecosystems.
AtıfScopus7WoS6OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ4Nurses’ Opinions About Patient Restraint Methods in a Psychiatric Hospital and Their Ethical Sensitivity
Durmaz, Yadigar Çevik; Ersöğütçü, Filiz
Methods of restraint can be used to prevent hospitalized psychiatric patients from injuring themselves or others, but use of restraints causes various ethical problems in psychiatric nursing. This study examined the relationship between nurses’ sociode-mographic characteristics, types of restraint methods used, nurses’ opinions about those methods, and their level of ethical sensitivity toward their use. We found the moral sensitivity of our participants to be moderate, and sta-tistically significant differences were found related to marital status, shift type, and restraint method used. Based on our results, we recommend improving nurses’ working conditions, increas-ing their level of ethical knowledge, and expanding the number of stud-ies on these issues.
AtıfScopus1WoS1OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ1A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory
Fan, Huanbao; Feng, Junxiao; Bai, Wei; Wang, Hui; Akkurt, Nevzat; Li, Weidong; Gao, Jun; AliAkbaria, Omid; Xu, Qian
Based on the theory of moderate or intense low-oxygen dilution (MILD) combustion, a 3D steady-state CFD model coupling dual flue gas recirculation and dispersion combustion was developed to describe the flow field, combustion temperature field, wall temperature distribution, and NOx concentration field during the operation of a novel U-type radiant tube (N-URT). A user-defined function (UDF) method was implemented to simulate the dilution of O2 concentration in the combustion air due to external flue gas recirculation (E-FGR). The effects of the E-FGR ratio on combustion characteristics and NOx emission were evaluated. The simulated results were consistent with experimental results. The simulated NOx concentration at the outlet was reduced to 105.5 mg/m3 at 8% O2, which was about 35.2% lower than the conventional combustion method. The study found that when the E-FGR ratio was increased from 0 to 25%, the standard deviation of wall temperature decreased from 30.3 °C to 23.3 °C, and the non-uniformity coefficient decreased from 0.2598 to 0.2183, indicating an improvement in temperature uniformity. However, the thermal efficiency decreased from 82.1% to 76.2%. Moreover, at higher E-FGR ratios, the volume of the high-temperature region (above 1500 ℃) gradually decreased, and both the maximum flame temperature and the outlet NOx concentration decreased sharply. Regression equations for the E-FGR ratio (β) on the maximum combustion temperature (Tmax) and the outlet NOx concentration (CNOx) were obtained, and an E-FGR ratio greater than 13.4% was recommended to meet the emission requirements.
AtıfScopus14OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ1Deep learning based hybrid prediction model for predicting the spread of COVID-19 in the world's most populous countries
Utku, Anil
COVID-19 has a disease and health phenomenon and has sociological and economic adverse effects. Accurate prediction of the spread of the epidemic will help in the planning of health management and the development of economic and sociological action plans. In the literature, there are many studies to analyse and predict the spread of COVID-19 in cities and countries. However, there is no study to predict and analyse the cross-country spread in the world's most populous countries. In this study, it was aimed to predict the spread of the COVID-19 epidemic. The motivation of this study is to reduce the workload of health workers, take preventive measures and optimize health processes by predicting the spread of the COVID-19 epidemic. A hybrid deep learning model was developed to predict and analyse COVID-19 cross-country spread and a case study was carried out for the world's most populous countries. The developed model was tested extensively using RMSE, MAE and R2. The experimental results showed that the developed model was more successful in predicting and analysis of COVID-19 cross-country spread in the world's most populous countries than LR, RF, SVM, MLP, CNN, GRU, LSTM and base CNN-GRU. In the developed model, CNN performs convolution and pooling operations to extract spatial features from the input data. GRU provides learning of long-term and non-linear relationships inferred by CNN. The developed hybrid model was more successful than the other models compared, as it enabled the effective features of the CNN and GRU models to be used together. The prediction and analysis of the cross-country spread of COVID-19 in the world's most populated countries can be presented as a novelty of this study.
AtıfScopus23WoS20OpenAlex31İncele - MakaleAçık Erişim2023Scopus SJRQ2Binary PCL–waste photopolymer blends for biodegradable food packaging applications
Gürler, Nedim; Pekdemir, Mustafa Ersin; Torğut, Gülben; Kök, Mediha
The aim of this study is to prepare waste photopolymer (WPP) / poly ɛ-caprolactone (PCL) blends that can be used in food packaging with different ratios (5%, 10%, 20% and 30%) WPP. The structural properties of the blend films were characterized by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Opacity, surface color, water vapor permeability and shape memory properties of these films were examined. Pure PCL film exhibited more thermal stability compared to PCL/WPP blend films. Therewithal, the glass transition temperature of the pure PCL film showed a shift. Water vapor permeability improved with the addition of WPP. L*, a* and transmittance values reduced with increasing WPP, but b* value increased. It was thought that these polymer blends would enable to be used as packaging material in terms of compatibility and waste evaluation.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ2Shape Memory Polymer-Based Nanocomposites Magnetically Enhanced with Fe3O4 Nanoparticles
Pekdemir, Mustafa Ersin; Aydin, Derya; Selçuk Pekdemir, Sibel; Erecevit Sönmez, Pınar; Aksoy, Edanur
This work aimed to investigate the effect of magnetic Fe3O4 nanoparticles (MNP), which are known to have a wide range of applications in recent years, on nanocomposite films prepared with shape memory polymers. Herein, PLA–PEG blend nanocomposite films were prepared by solution casting method using MNP at different ratios. PLA–PEG Blend/MNP nanocomposite films were characterized with Attenuated total reflection infrared spectroscopy (ATR-IR) to determine the –C=O stretching of PLA and Fe–O stretching signals of Fe3O4. The thermal stability, morphology, and magnetic behavior were studied by comparing the results among PLA–PEG blend, PLA–PEG blend/MNP nanocomposite with thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and a vibrating sample magnetometer (VSM), respectively. The effect of MNP on the shape memory properties of PLA/PEG blend was investigated. Moreover, the comparison of antimicrobial activity between PLA/PEG blend and PLA–PEG blend/MNP nanocomposite films were conducted by the disk diffusion method. The results showed that MNP increased the thermal stability of the PLA/PEG blend and the nanocomposites inhibited the growth of C.albicans microorganism. Graphical Abstract: [Figure not available: see fulltext.].
AtıfScopus41WoS39OpenAlex42İncele - MakaleAçık Erişim2023Scopus SJRQ1DEEP LEARNING BASED AN EFFICIENT HYBRID PREDICTION MODEL FOR COVID-19 CROSS-COUNTRY SPREAD AMONG E7 AND G7 COUNTRIES
Utku, Anil
The COVID-19 pandemic has caused the death of many people around the world and has also caused economic problems for all countries in the world. In the literature, there are many studies to analyze and predict the spread of COVID-19 in cities and countries. However, there is no study to predict and analyze the cross-country spread in the world. In this study, a deep learning based hybrid model was developed to predict and analysis of COVID-19 cross-country spread and a case study was carried out for Emerging Seven (E7) and Group of Seven (G7) countries. It is aimed to reduce the workload of healthcare professionals and to make health plans by predicting the daily number of COVID-19 cases and deaths. Developed model was tested extensively using Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and R Squared (R2). The experimental results showed that the developed model was more successful to predict and analysis of COVID-19 cross-country spread in E7 and G7 countries than Linear Regression (LR), Random Forest (RF), Support Vector Machine (SVM), Multilayer Perceptron (MLP), Convolutional Neural Network (CNN), Recurrent Neural Network (RNN) and Long Short-Term Memory (LSTM). The developed model has R2 value close to 0.9 in predicting the number of daily cases and deaths in the majority of E7 and G7 countries.
AtıfScopus9OpenAlex11İncele - MakaleAçık Erişim2023Scopus SJRQ3Statistical Analysis and EEG Signal Filtering Using Design of Window Function Based on Optimization Methods
Serbet, Fatmanur; Kaya, Turgay
The window functions, which are widely used in Finite Impulse Response (FIR) digital filter design with the Fourier Series Methods, aim to eliminate the oscillations adversely affecting the filter performance that occur during the filter design. Window functions, which were developed with different methods in the literature, were designed with three different optimization techniques in this study. By using Particle Swarm Optimization (PSO), Grey Wolf Colony Optimization (GWCO), Cuckoo Search Optimization (CSO) algorithms, which are among current metaheuristic optimization methods, new window functions are designed for FIR digital filter design such that the designed new window functions have different window coefficients and design parameters. The difference of the designed window functions was analyzed with the Friedman and Wilcoxon tests, which are statistical data analysis methods, and the originality of the designed window functions was proven. FIR digital filters that can perform the same operation as the designed window functions have been produced and the results obtained by performing the filtering application of the EEG signal with the produced filters are presented in the study.
AtıfScopus9WoS6OpenAlex7İncele - MakaleYalnız künye2023Scopus SJRQ2Silver-Doped Diamond-Like Carbon (DLC:Ag) Nanocomposite Films for Solar Tracking Applications
Aslan, Naim; Kurt, Mustafa Şükrü; Koç, Mümin Mehmet
Diamond-like carbon (DLC) films are often investigated for their mechanical properties. In this report, we assessed the electrical and photovoltaic characteristics of DLC:Ag composite films produced for solar tracking and/or photodetector device purposes. We used the magnetron sputtering technique to prepare DLC:Ag thin films where DLC and Ag were co-deposited on Si wafers. Structural characterization of the thin films was performed using AFM, EDX, and Raman spectroscopy. Current–voltage, capacitance–voltage and conductance–voltage characterizations were employed to assess the electrical characteristics and photovoltaic characteristics of the DLC:Ag thin films. I–V characteristics were characterized under various illumination intensities to assess the effect of light intensity on the DLC:Ag composite films. We found that silver-doped DLC composite thin films are responsive to light and exhibit detector-like behaviour. Barrier height was found to be between 0.55 eV and 0.81 eV while the ideality factor was calculated to be between 1.94 and 7.11. It was found that photovoltaic and diode properties were affected by applied illumination intensities. C–V characteristics indicated that the electrical properties of the thin films are responsive to the signal frequency. The density of interface states was calculated which was thought to be a factor related to this behaviour.
AtıfScopus17WoS16OpenAlex14İncele - MakaleYalnız künye2023Scopus SJRQ2Microplastic pollution in two remote rivers of Türkiye
Gündoğdu, Sedat; Kutlu, Banu; Özcan, Tahir; Büyükdeveci, Ferhat; Blettler, Martin C. M.
Microplastic pollution in aquatic ecosystems presents an emerging environmental threat that can have adverse effects on ecology, endanger aquatic species, and result in economic damage. Despite the numerous studies reporting the presence of microplastics in marine environments, research into their presence in freshwater systems or inland waters remains limited. This study aimed to assess the level of microplastic pollution transported by the Munzur and Pülümür Rivers and some small rivers that flow into the Uzunçayır dam lake, which is the confluence of the Munzur and Pülümür Rivers in Türkiye. Samples were collected from 23 stations, with the concentration of microplastics ranging from 0.01 MP/m3 at P-4 station to 28.21 MP/m3 at P-10, a station located near a city. Microplastics comprise four types: fiber, film, fragment, and glitter. The average size of microplastics was 1.46 ± 0.05 mm, with the average size of fibers, films, fragments, and glitter-type microplastics being 1.58 ± 0.07 mm, 1.23 ± 0.10 mm, 1.21 ± 0.11 mm, and 0.78 ± 0.16 mm, respectively. The most frequent polymers were polyethylene (31.8%), polystyrene (21.1%), and polypropylene (10.5%). Despite being considered remote and less populated rivers compared to other river systems in Türkiye, all sampling sites showed varying concentrations of microplastics.
AtıfScopus34OpenAlex37İncele - MakaleYalnız künye2023Scopus SJRQ1Cytoprotective, antimutagenic/antirecombinogenic and antibacterial properties of Lallemantia iberica extracts
Yilmaz Kardas, Begumhan; Diken, Mehmet Emin; Bayhan, Hamza; Acar, Mikail; Dogan, Serap
BACKGROUND: Plants have important chemical compounds to protect organisms from many mutagens but they may also have dangerous toxic substances that must be tested before use. Lallemantia iberica has been used by local people for treatment of some diseases but it was never tested for its cell protective and antimutagenic/antirecombinogenic properties. In this study, it was aimed to determine the cytoprotective, antimutagenic/antirecombinogenic, antibacterial, antioxidant and phenolic profile of L. iberica by MTS assay, micronucleus test/somatic mutation recombination test (SMART), disc diffusion method, ABTS/DPPH tests and liquid chromatography (LC), respectively. RESULTS: MTS assay results showed that both of the extracts supported the normal growth of healthy human lymphocytes and there was no significant difference between extracts. Although there was no significant increase in micronucleus concentration (‰) of the cultures treated with ethanol or methanol extracts, methanol extract caused slightly lower micronucleus concentration (12.64 ± 3.65‰) than the ethanol extract (24.46 ± 4.50‰). SMART results showed that ethanol and methanol extracts prevented harmful mitotic recombination. Lallemantia iberica also showed antibacterial activity against all of the strains tested, and the largest inhibition zones were observed with Pseudomonas aeruginosa (17.9 mm) and Enterobacter aerogenes (13.8 mm). Methanol extracts showed better antioxidant activities (ABTS IC50: 104.07 μg mL−1, DPPH IC50: 58.8 μg mL−1) than ethanol extracts (ABTS IC50: 344.03 μg mL−1, DPPH IC50: 233.7 μg mL−1). According to the LC results, the most abundant phenolic compounds were rutin hydrate (1796.4 ± 62.9 mg kg−1) and p-coumaric acid (228.1 ± 7.60 mg kg−1). CONCLUSION: Lallemantia iberica extracts had cell-protective, antimutagenic/antirecombinogenic, antibacterial and strong antioxidant characteristics in relation to their rich phenolic content.
AtıfScopus7WoS5OpenAlex9İncele - MakaleAçık Erişim2023Scopus SJRQ2Prediction of Paleoclimate of Eocene Salt, Kohat Basin, Khyber Pakhtunkhwa, Pakistan
Ahmed, Noor; Kashif, Muhammad; Dou, Bin; Tariq, Muhammad; Sami, Muhammad; Ullah, Zahid
Fluid inclusion analysis is a significant tool to evaluate the paleoclimate reconstruction of ancient evaporite precipitation. The current study is a significant research to evaluate the ancient climate of Eocene salt. The thin sections petrography, XRD, SEM, Laser raman spectroscopy, and Microthermometric analysis have been used to evaluate the prediction of paleoclimate of Eocene salt. Two sections were measured and samples were collected for thin sections analysis. Under thin section, halite is mainly cubic shape euhedral form and also consists of other minerals like gypsum, anhydrite, polyhalite, sylvite, and dolomite. Geochemical data obtained from XRD, indicates the presence of Na and Cl as major ions, with subordinate Ca, SO4, Mg, etc. Laser raman spectroscopy analysis reveals that water and CO2 fluids are trapped within the inclusions. Generally, fluid inclusion analysis and geochemistry are useful tools to evaluate the origin and paleoclimate of Eocene Salt. Geochemical data shows that the Eocene salt is not a product of marine water but it also consists of meteoric and surface water. Low concentration of Br- and presence of SO4 shows that halite is precipitated from SO4 type water. Homogenization temperature (Th) ranges from 14°C to 43°C. Microthermometric data shows that fluids were entrapped during and after salt precipitation. Histogram of fluid inclusions also shows that primary and secondary inclusions have discontinuous behavior that shows inclusions were not trapped at the same time of deposition. Some are formed at the time of precipitation and some are formed after precipitation. The presence of impurities like Fe, Mg, Ca, and other ions within the halite show that halite was exposed to the atmosphere by tectonic activities and meteoric water/surface water percolates through fractures and is trapped as inclusion along with the micro fractures. So the Th variation indicates that fluid was trapped at various seasons. Low temperature show inclusions were trapped in winter/spring seasons and high temperatures indicates inclusions were trapped in the summer season. The maximum homogenization temperature of fluid inclusions in halite is 43°C which is closed to the maximum climatical temperature of the present summer. The result shows that Eocene salt has been deposited in hot, arid, and dry conditions during Eocene time. The alternating period of desalination and evaporation is responsible for the formation of soluble halite.
AtıfScopus3WoS3OpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ1Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties
Güler, Ömer; Kavaz, E.; Güler, Seval Hale; Almisned, Ghada; Özkul, İskender; Basgoz, Oykum; Tekin, H.O.
The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.
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