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
- DüzeltmeYalnız künye2023Scopus SJRQ1Corrigendum to “A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory” [Fuel 346 (2023) 128321] (Fuel (2023) 346, (S0016236123009341), (10.1016/j.fuel.2023.128321))
Fan, Huanbao; Feng, Junxiao; Bai, Wei; Wang, Hui; Akkurt, Nevzat; Li, Weidong; Gao, Jun; AliAkbaria, Omid; Xu, Qian
The authors regret to inform that Table 1 in the final (citable) version of our article [Fuel 346 (2023) 128321] published in Fuel has a serious error; some key data in Table 1 (page 4, Section 2.2) corresponded incorrectly to variables. This was mainly due to our carelessness and was not caught in time while reviewing proofs for our publications. The correction is necessary to improve the academic accuracy of the article and for ease of reference for the readers. We are therefore publishing this correction. Specifically, the pre-exponential factor Ar and activation energy Ea of 2CO + O2 → 2CO2 should be 2.239 × 1012 1/s and 1.7 × 108 J/kg·mol, respectively. The pre-exponential factor Ar and activation energy Ea of 2H2 + O2 → 2H2O should be 9.87 × 108 1/s and 3.1 × 107 J/kg·mol, respectively. Thank you for your understanding and the previous efforts of all the reviewers and editors. Reference [1] Huanbao Fan, Junxiao Feng, Wei Bai, Hui Wang, Nevzat Akkurt, Weidong Li, Jun Gao, Omid AliAkbaria, Qian Xu, A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory, Fuel 346 (2023) 128321. DOI: https://doi.org/10.1016/j.fuel.2023.128321. The correct version of Table 1 is as follows: The authors would like to apologise for any inconvenience caused.
- MakaleYalnız künye2023Scopus SJRQ3Trematodon and Ptychostomum Species New to Turkey and South-West Asia
Erata, Hüseyin; Batan, Nevzat; Alataş, Mevlüt; Ezer, Tülay
Abstract: During the recent bryofloristic studies in the Karçal mountain of the Artvin region (Caucasus), north of Turkey’s East Black Sea region, Trematodon ambiguus and Ptychostomum cyclophyllum were found as new species to Turkey and Southwest Asia. Descriptions, illustrations, new localities, geographic distribution, ecological characteristics, and comparisons with morphologically similar taxa were provided.
AtıfScopus3OpenAlex8
İncele - MakaleYalnız künye2023Scopus SJRQ1Sustainability performance analysis of micro-mobility solutions in urban transportation with a novel IVFNN-Delphi-LOPCOW-CoCoSo framework
Ecer, Fatih; Küçükönder, Hande; Kayapınar Kaya, Sema; Faruk Görçün, Ömer
Almost all megacities worldwide are under pressure from environmental pollution and excessive resource usage due to rapid urbanization and increasing urban population. Within this scope, micro-mobility solutions (MMSs), an extension to the primary urban transportation network, have become even more critical recently. However, when we executed a preliminary investigation concerning MMSs' sustainability, we noted some critical theoretical and managerial gaps: (1) the number of studies assessing MMSs using decision-making approaches is excessively scarce, (2) no paper in the literature deals with the MMSs' sustainability performance, and (3) there are no commonly accepted criteria set to assess the sustainability of the MMSs in the literature. The current study aims to present a practical and robust decision-making framework that can overcome excessively complicated uncertainties to evaluate the sustainability performance of MMSs. Further, it suggests a novel methodological framework, i.e., Delphi, Logarithmic Percentage Change-Driven Objective Weighting (LOPCOW), and Combined Compromise Solution (CoCoSo) methods with interval-valued fuzzy neutrosophic number (IVFNN) information, which can be defined as a reconciliation tool to set the criteria affecting the assessment processes. Findings present that computing time, scenic adoption, and accidents are the foremost criteria, whereas mini-electric VH, powered standing scooter, and powered seated scooter are the most promising MMSs, respectively. Findings reveal that computing time, scenic adoption, and accidents are the critical factors for the sustainability assessment of MMSs, whereas mini-electric VH, powered standing scooter, and powered seated scooter are the most promising MMSs, respectively. The current paper's overall outcomes and findings can assist practitioners and policy-makers in the urban transportation industry in setting sustainability policies and investing in the more rational and sustainable MMSs.
AtıfScopus104WoS91OpenAlex112İncele - MakaleYalnız künye2023Scopus SJRQ1Carbide slag recycling to fabricate shape-stable phase change composites for thermal energy storage
Xiong, Yaxuan; Wang, Huixiang; Ren, Jing; Nevzat, Akkurt; Xu, Qian; Nie, Binjian; Li, Chuan; Ding, Yulong
The mining and processing of traditional skeleton materials inevitably generates carbon emissions and pollutes the surrounding environment. To make full use of industrial solid waste, this work innovatively used carbide slag as skeleton material and Na2CO3 as phase change material (PCM) to fabricate shape-stable phase change composites (SSPCCs) via the cold-compression & hot-sintering method. Seven SSPCCs were fabricated with different mass ratios of carbide slag to Na2CO3. Then, the thermal energy storage (TES) performance, mechanical property, micromorphology, chemical compatibility as well as thermal cycling stability were investigated. The results showed that the carbide slag could combine with Na2CO3 to fabricate SSPCCs; Sample CN5 achieved the optimal performance with the mass ratio 52.5:47.5 of carbide slag to Na2CO3; Sample CN5 achieved a TES density of 993 J/g in the range of 100 to 900 °C, a compressive strength of 22.02 MPa and a maximal thermal conductivity of 0.62 W/(m·K); Both carbide slag and Na2CO3 were distributed uniformly in sample CN5, while good thermal stability after the 100 heating/cooling cycles and good chemical compatibility between the carbide slag components and the Na2CO3 were observed.
AtıfScopus34OpenAlex30İncele - MakaleYalnız künye2023Scopus SJRQ2Contribution of Mechanical Activation for Obtaining Potassium Chloride from Microcline
Alyosif, Bahaa; Uysal, Turan; Aydemir, Muhammet Kürşat; Erdemoğlu, Murat
The effect of intensive milling on the conversion of microcline (KAlSi3O8) to potassium chloride (KCl) occurred during the chlorination roasting process for artificial KCl production was investigated. A feldspar ore with 10.89% K2O grade and containing microcline was dry milled by a planetary ball mill for mechanical activation. Milled ore mixed with calcium chloride was roasted at temperatures between 500 and 1000 °C to get the chlorination roasting process. The product was then leached in water to dissolve KCl occurring during the roasting, which will be precipitated from the pregnant leach solution by evaporation. Results showed that potassium recovery from the unmilled ore increased rapidly up to 800 °C, and dramatically decreased at higher temperatures due to the removal of KCl from the furnace by means of evaporation. A potassium recovery of 31.95% was achieved by the unmilled ore, whereas it was 88.43% when 15 min milled ore was roasted at 750 °C. It was concluded that intensive milling caused mechanical activation of microcline to reduce the roasting temperature of the chlorination roasting process.
AtıfScopus12WoS11OpenAlex10İncele - MakaleYalnız künye2023Scopus SJRQ1The relationship between unemployment anxiety, job satisfaction and migration attitude among the next generation of Turkish nurses: A cross-sectional study
Öncü, Emine; Köksoy Vayısoğlu, Sümbüle; Karadağ, Gülendam; Şahin Orak, Nuray; Selçuk Tosun, Alime; Yüksekol, Özlem Doğan; Çatıker, Aslıhan; Yalçın, Gülcan Çiftçioğlu
Background: The global nursing shortage is complex and multifaceted. Despite the policy of increasing the number of nurses, concerns about the sustainability of the nursing workforce in Turkey continue. Aim: To evaluate the relationship between unemployment anxiety, job satisfaction, and migration attitudes among Turkish nursing candidates. Methods: A cross-sectional study was conducted with 1100 nursing candidates between April and June 2022. The data gathered from the “Personal Form, Job Satisfaction, and Brain Drain Attitudes Scale” were analyzed using logistic regression and decision tree analysis. Results: Of the participants, 67.1% were female, and the mean age was 22.6 ± 1.7 years. Being male (OR = 1.317, 95% Cl 0.994–1.743) having a low income (OR = 1.754, 95% Cl 1.334–2.306), feeling insecure about the future (OR = 2.340, 95% Cl 1.312–4.175), expecting a lower wage than desired (OR = 2.015, 95% Cl 1.132–3.586), and employment precariousness (OR = 1.786, 95% Cl 1.355–2.353) increase the possibility of experiencing high unemployment anxiety. On the other hand, family support for living abroad (OR = 0.579, 95% CI 0.408–0.821) and job satisfaction (OR = 0.799, 95% CI 0.692–0.921) decrease unemployment anxiety (p < 0.05). According to the results of the decision tree analysis, the host country's pull factors are the best predictors of the nursing candidates' intention to work abroad as nurses (p < 0.05). Conclusion: The increasing prevalence of unemployment anxiety and migration tendencies among nursing candidates requires the evaluation of policies aimed at increasing the number of nursing graduates in Turkey.
AtıfScopus9OpenAlex16
İncele - MakaleAçık Erişim2023Scopus SJRQ1A Multi-Input Convolutional Neural Networks Model for Earthquake Precursor Detection Based on Ionospheric Total Electron Content
Uyanık, Hakan; Şentürk, Erman; Akpınar, Muhammed Halil; Ozcelik, Salih T. A.; Kokum, Mehmet; Freeshah, Mohamed; Sengur, Abdulkadir
Earthquakes occur all around the world, causing varying degrees of damage and destruction. Earthquakes are by their very nature a sudden phenomenon and predicting them with a precise time range is difficult. Some phenomena may be indicators of physical conditions favorable for large earthquakes (e.g., the ionospheric Total Electron Content (TEC)). The TEC is an important parameter used to detect pre-earthquake changes by measuring ionospheric disturbances and space weather indices, such as the global geomagnetic index (Kp), the storm duration distribution (Dst), the sunspot number (R), the geomagnetic storm index (Ap-index), the solar wind speed (Vsw), and the solar activity index (F10.7), have also been used to detect pre-earthquake ionospheric changes. In this study, the feasibility of the 6th-day earthquake prediction by the deep neural network technique using the previous five consecutive days is investigated. For this purpose, a two-staged approach is developed. In the first stage, various preprocessing steps, namely TEC signal improvement and time-frequency representation-based TEC image construction, are performed. In the second stage, a multi-input convolutional neural network (CNN) model is designed and trained in an end-to-end fashion. This multi-input CNN model has a total of six inputs, and five of the inputs are designed as 2D and the sixth is a 1D vector. The 2D inputs to the multi-input CNN model are TEC images and the vector input is concatenated space weather indices. The network branches with the 2D inputs contain convolution, batch normalization, and Rectified Linear Unit (ReLU) activation layers, and the branch with the 1D input contains a ReLU activation layer. The ReLU activation outputs of all the branches are flattened and then concatenated. And the classification is performed via fully connected, softmax, and classification layers, respectively. In the experimental work, earthquakes with a magnitude of Mw5.0 and above that occurred in Turkey between 2012 and 2019 are used as the dataset. The TEC data were recorded by the Turkey National Permanent GNSS Network-Active (TNPGN-Active) Global Navigation Satellite System (GNSS) stations. The TEC data five days before the earthquake were marked as “precursor days” and the TEC data five days after the earthquake were marked as “normal days”. In total, 75% of the dataset is used to train the proposed method and 25% of the dataset is used for testing. The classification accuracy, sensitivity, specificity, and F1-score values are obtained for performance evaluations. The results are promising, and an 89.31% classification accuracy is obtained.
AtıfScopus27OpenAlex19İncele - MakaleAçık Erişim2023Scopus SJRQ1Greening Industrially Applied Toxic Cadmium Plating with γ-Ni2Zn11 Alloy in Deep Eutectic Solvents: Promising Electroplating Efficiency and Chemical Corrosion Resistance
Cihangir, Salih
Cadmium is an industrially applied plating metal used in aerospace applications, but electrodeposition of cadmium is toxic, and current production method will soon be banned. Therefore, electrodeposition of alternative alloys in environmentally friendly solutions is an attractive research area. An additive-free, nonaqueous, deep eutectic solvent (DES) containing Ni and Zn halide salts is developed in a greener environmental method. Gamma-phase nanocrystalline Ni2Zn11 is coated onto hot-rolled mild steel via pulse reverse current (PRC) in the developed nonaqueous solvent. The employed DES’ relatively low viscosity and sufficient conductivity enable the simultaneous reduction of Ni2+ and Zn2+ cations on microelectrode. Electrochemical quartz crystal microbalance (eQCM) analysis proves the absence of the commonly reported problem of electrode blocking during electrodeposition, revealing an efficiency of 86.07%. Appropriate PRC parameters are applied for scaled macroelectrode deposition. The plating profile exhibits 20 μm-thick alloy deposition without cracks around 3 h. Scanning electron microscopy–electron-dispersive spectroscopy and X-ray diffraction analyses reveal that 15.5 wt% Ni is in the nanograin phase, and all crystal planes belong to the γ-Ni2Zn11 phase, which is needed as an alternative to cadmium plating. Hardness and corrosion tests performed on the γ-Ni2Zn11 coating reveal better hardness and corrosion resistance with supporting morphological evidence.
AtıfScopus14WoS13OpenAlex16İncele - MakaleYalnız künye2023Scopus SJRQ2Genotoxic effect of iron oxide (Fe2O3) nanoparticles on Triticum aestivum (wheat)
Tasar, Neslihan
Industrial activities and unconscious consumption of natural resources cause environmental pollution with the rapid increase in the world population. As a result of the widespread use of iron oxide nanoparticles (Fe2O3 NP) with nano-industrial activities, it is predicted that this NP will accumulate in the air, water, and soil. In the present study, the purpose was to find out the genotoxic effects on root meristem cells of the Triticum aestivum L. plant, which is an indicator organism exposed to 20–40 nm Fe2O3 NPs at different concentrations (100, 200, and 400 ppm). The amount of Fe2O3 NP accumulated in T. aestivum used in the study was determined with x-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), SEM element map, and EDS characteristic spectrum. All concentrations of Fe2O3 NP caused significant decreases in the mitotic index. Fe2O3 NPs significantly increased the frequency of mitotic abnormalities in T. aestivum root tip cells at all treatment times and all concentrations when compared to the control. Fe2O3 NPs were formed by various mitotic abnormalities such as loss of genetic material, deconstructed prophase, adhesion, chromosome groupings in metaphase, deconstructed metaphase, C-Metaphase, chromosomal loss, chromosomal fracture, polyploidy, deconstructed anaphase, lagging chromosome, fragment, polar deviation, bridging, propagation, asynchronous division, star anaphase, multipolarity, and deconstructed telophase. All these results show that Fe2O3 NPs are genotoxic and clastogenic and may also cause DNA damage. Briefly, these data show that Fe2O3 NPs taken by organisms may pose a danger to the organism and the upper consumer. These findings also show that the production and use of Fe2O3 NPs, which affect organisms, must be controlled, and ultimately, be safely disposed of to reduce their bioaccumulation. Research Highlights: In the present study, the purpose was to find out the genotoxic effects on root meristem cells of the Triticum aestivum L. (bread wheat) plant, which is an indicator organism exposed to 20–40 nm Fe2O3 NPs at different concentrations (100, 200, and 400 ppm). The amount of Fe2O3 NP accumulated in T. aestivum used in the study was determined with x-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), SEM element map, and EDS characteristic spectrum. The mitotic index was calculated to reveal the genotoxic effect. “Loss of genetic material, deconstructed prophase, adhesion, chromosome groupings in metaphase, deconstructed metaphase, C-Metaphase, chromosomal loss, chromosomal fracture, polyploidy, deconstructed anaphase, lagging chromosome, fragment, polar deviation, bridging, propagation, asynchronous division, star Chromosomal abnormalities such as anaphase, multipolarity, and deconstructed telophase” were visualized. Fe2O3 NPs are genotoxic and clastogenic and may also cause DNA damage.
AtıfScopus10WoS7OpenAlex11İncele - MakaleYalnız künye2023Scopus SJRQ1Buoyancy-driven flow and thermal activity of nano-enhanced phase change material in inversed U-shaped chamber
Younis, Obai; Abderrahmane, Aissa; Laidoudi, Houssem; Akkurt, Nevzat; Fadhl, Bandar M.; Guedri, Kamel
This work aims to contribute to the positive evolution towards a green world and green energy by studying the natural convection of Nano-Enhanced Phase Change Material NEPCM in an inverted U-shaped cavity. The side walls of the cavity are kept at a cold temperature, while the upper corrugated wall and the lower wall are insulated with the expectation of the hot square body. The governing equations were solved numerically using the Galerkin finite element method (GFEM). The effects of the following factors on the heat transfer rate are presented and discussed: Rayleigh number (Ra = 103–106), number of ripples of the upper wall (N = 1–4), position of the square body (left, centre, and right), volume fraction of nanoparticles (ϕ = 0–0.08), and magnetic field strength (Ha = 0–100). It was found that the effect of N on the heat transfer rate was insignificant, while increasing ϕ reduced the heat transfer rate. In addition, placing the square body near the cold sidewalls (left or right position) improved the averaged Nusselt number (Nuavg), especially at low values of Ra. At the highest Ra studied, increasing Ha reduced the Nuavg by 15 %.
AtıfScopus11OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ1The structure, optical basicity, ligand field strength and shielding parameters of alkali/alkaline borate glasses doped with V2O5
Sayyed, M.I.; Abdel-Ghany, A.M.; Askin, A.; Sedqy, E.M.; Sadeq, M.S.
In this work, we study the structural, optical and radiation shielding properties of Na2O–CaO-borate glass doped with different amounts of V2O5. A glass system with the composition (10.5CaO+ 16.5Na2O+ (73-x)B2O3+ xV2O5; where x = 0, 2.5, 5 and 10.5 mol%) was produced following the melt quenching technique. The molar volume and density of glasses both increase with the increase in V2O5:B2O3 ratios. Moreover, the average ligand field strength reduced from 2.32 to 2.15 × 1016 cm2 with the increase in V2O5:B2O3 ratios, which correlates with the increased values of molar volume and interatomic separations. Furthermore, the optical basicity of the glass samples increased from 0.601 to 0.666 with increasing V2O5:B2O3 ratios. The optical absorption spectra are studied for further investigation of the optical features. To extract the absorption edge and the absorption bands, a deconvolution process was applied to the absorption spectra. The obtained bands from this deconvolution process confirmed the presence of vanadium in its oxidation states V3+, V4+ and V5+. Furthermore, more additions of V2O5 produced an obvious reduction in Eg values from 3.69 to 3.08 eV along with a redshift in the fundamental absorption edges. These results were attributed to the further creation of nonbridging oxygens within the glass matrix. Furthermore, the addition of V2O5 rather than B2O3 enhances the radiation shielding parameters. Accordingly, the CaNaBV10.5 glass sample is the best attenuator among the fabricated CaO–Na2O–B2O3–V2O5 glasses due to the highest mass attenuation coefficient and lowest half-value layer. Moreover, the half-value layer values of the present glasses were compared to some common materials in the radiation shielding field. From this comparison, we concluded that all glass samples are better than commercial glass windows and ordinary concrete.
AtıfScopus19OpenAlex21İncele - MakaleYalnız künye2023Scopus SJRQ1Heat loss optimization and economic evaluation of a new fourth generation district heating triple pipe system
Chen, Xingli; Ren, Ling; Zheng, Qiang; Yang, Gang; Akkurt, Nevzat; Liu, Lin; Liu, Zhiwei; Qiang, Yujie; Yang, Huachao; Xu, Qian
In response to the heat loss caused by the temperature difference between the heating pipes and external environment during the pipe transportation, heat contradiction between the total heat loss of the piping system and heat transfer between tubes, as well as economic balance between the cost of heat loss and cost of material loss. Based on TOTS (Two-supply/One-return, triple pipe structure) heat loss theory of the fourth-generation district heating system, this paper optimizes structure of pipes by setting dimensionless characteristic parameters θ and β. Finally, a mathematical model is proposed to calculate economic efficiency of pipeline network by considering the cost of initial construction material loss and operation heat loss of the pipe. Results show that, from energy perspective, comprehensive heat as system energy consumption evaluation index is positively correlated with θ, decreases first and then increases as β increases. Total heat loss of system dominates comprehensive heat. Lowest comprehensive heat of system is 18.12 w/m for θ of 0.1945 and β of 0.0739. From economic perspective, total system loss cost as system economic evaluation index is positively correlated with both θ and β. Total system heat loss cost dominates total system loss cost. Lowest total system loss cost is $29.39/m for θ of 0.1945 and β of 0.0509.
AtıfScopus16OpenAlex20İncele - MakaleYalnız künye2023Scopus SJRQ2Ag seed layer effects on SnO2 thin films for triboelectric devices
Yüzüak, E.; Yüzüak, G. Durak
Materials with triboelectric properties are critical to boosting the efficiency of triboelectric nanogenerators (TENG) by gathering power from waste force and mechanical movement. In this study, we explored tin-oxide (SnO2) thin films with silver (Ag) seed layer properties for friction surfaces at TENGs. Investigation of the triboelectric behavior of semi-conductor/polymer coupling structured TENGs formed by thin films with and without Ag seed layer after heat treatment was explored by X-ray diffraction (XRD), electron microscopy (SEM), atomic force microscopy (AFM), and semi-logarithmic current-voltage measurements. Similar structural characterization studies were carried out in indium tin oxide coated polyethylene terephthalate film (PET/ITO) for the polymer friction layer. Semiconductor/polymer coupling structured TENG efficiency was evaluated in contact-separation mode and the output voltage-current was enhanced to 80 V, 4 μA, and 210 μW of output power calculated by depositing a SnO2 thin film on an Ag seed layer, respectively. Our findings offer a different perspective for synthesizing the semi-conductor/polymer coupling structured TENGs for promising applications in a range of application technologies.
AtıfScopus2WoS2OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ1Investigation of surface morphology, optical properties and the gamma radiation effect on selenium coated glass substrate containing rare earth oxide
Taşgin, Yahya; Kanca, Muhammed Sait; Kök, Mediha
In this study, in order to add different properties and functions to inorganic amorphous glasses, the applicability and effects of the thin film coating produced by thermal evaporation method were examined by metallographically imaging the effects of 3%–5% CeO2 and Tm2O3 rare earth elements (REE) oxide added to selenium to change the morphology of the glass surface. As a result of the study, it has been proved that CeO 2 and Tm2O3 added to selenium can be coated by thermal evaporation method with AFM images taken from the glass surface and metallographic analyses (SEM, EDX, Mapping). The lowest roughness value was observed in 95Se–5CeO2 coating glass substrate. In all coatings, selenium, which is the main sample, was found to be active, and XRD measurements showed that the thin films were formed by agglomeration on the (101) plane. According to UV-VIS measurements, the lowest optical band energy range was observed in the 95Se–5CeO2 coating.
AtıfScopus11WoS10OpenAlex12İncele - MakaleYalnız künye2023Scopus SJRQ2Detection of hateful twitter users with graph convolutional network model
Utku, Anıl; Can, Umit; Aslan, Serpil
Today, hate speech is widespread and persistent in various forms on social networking platforms, targeting different minority groups. These attacks can be carried out using various factors such as racial, religious, gender, and physical disability, etc. Considering the number of people and their interactions, social networks are the most important channels through which these discourses spread. The social network structure is considered a set of nodes and edges and is very suitable for the graph structure. The multidimensional structure of social networks carries social network data from Euclidean space to non-Euclidean space. In non-Euclidean space, the graph structure is used to represent data effectively. In this respect, solving the hate speech problem with graph-based methods in a complex dimensional space can produce more impressive results. In this study, a powerful method based on the Graph Convolutional Network (GCN) model, which is rarely used in this field, was proposed for the detection of hateful Twitter users in social networks. Well-known machine learning methods were used to measure the performance of this method. According to the results obtained, the proposed GCN model gave the most successful result.
AtıfScopus15WoS10OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ2Fabrication of hydroxyapatite-based nano-gold and nano-silver-doped bioceramic bone grafts: Enhanced mechanostructure, cell viability, and nuclear abnormality properties
Demirel, M.; Aslan, N.; Aksakal, B.; Arslan, M.E.
In this study, nano-gold (nAu) and nano-silver (nAg) were doped at the molar ratios of Molar5–Molar30 to the Hydroxyapatite (HAp)-based bioceramic bone graft synthesized by the sol–gel method. The effects of nAu and nAg on structural, mechanical, cell viability, and nuclear abnormality of the synthesized bioceramic grafts were evaluated. The chemical and morphological properties of the bone grafts after production were examined through XRD and SEM–EDX analyses and mechanical tests. To determine the biocompatibility of the bone grafts, cell viability tests were performed using human fibroblast cells. In the cytotoxicity analyses, only HAp and HAp-nAu5 grafts did not show toxicological properties at any concentration, while HAp-nAg5 among the nAg-containing grafts gave the best results at the 200–100 μg/mL concentrations and showed significant cytotoxicity in human fibroblast cells. The other nAu-containing grafts showed toxicological properties in the concentration range of 200–50 μg/mL and nAg-containing grafts in the concentration range of 200–100 μg/mL against the negative control. The micronucleus (MN) analyses showed that the lowest total MN and L (lobbed) amounts, while the lowest total N (notched) amount, was obtained from the only HAp graft. It was found that the nAg-doped bone grafts gave higher total MN, L, and N amounts compared to the nAu-doped bone grafts. Furthermore, while the mean nuclear abnormality (NA) values of all grafts gave close results, the highest values were again obtained from the nAg-doped bone grafts.
AtıfScopus7WoS6OpenAlex9İncele - MakaleAçık Erişim2023Scopus SJRQ3WEAR AND ADHESION PROPERTIES OF MULTILAYER Ti/TiN, (/TiC)/ TiCN/ TaN THIN FILMS DEPOSITED ON Ti13Nb13Zr ALLOY BY CLOSED FIELD UNBALANCED MAGNETRON SPUTTERING
Aslan, Ali Kemal; Bahçe, Erkan
Ti13Nb13Zr alloy stands out as an alternative to Ti6Al4V alloy for orthopaedic joint implant applications due to its low modulus of elasticity, high mechanical properties, high corrosion resistance, high biocompatibility and low modulus of elasticity, as well as con-taining no cytotoxic elements. In this study, Ti13Nb13Zr alloy was coated with TiN/TiC/TiCN/TaN multilayer thin films by pulsed-dc CFBUMS method to increase wear resistance and improve surface properties. Characterization of the deposited films were con-ducted by XRD, SEM, AFM, pin-on-disk, progressive scratch experiments. As a result, it is observed that all the coatings enhanced the tribological properties of the Ti13Nb13Zr alloy surface. The 20-layer TiN/TiC/TiCN/TaN multilayer coatings gave the best results for wear resistance and adhesion properties. Enhancing the interlayer number resulted in increased wear and adhesion resistance. In addition, it was determined that using TiC instead of TiN in the interlayers gave higher results regarding adhesion, wear, and mechanical properties.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ1Orbitrap Mass Spectrometry-Based Profiling of Secondary Metabolites in Two Unexplored Eminium Species and Bioactivity Potential
Babacan, Ebru Yuce; Zheleva-Dimitrova, Dimitrina; Gevrenova, Reneta; Bouyahya, Abdelhakim; Balos, Mehmet Maruf; Cakilcioglu, Ugur; Sinan, Kouadio Ibrahime; Zengin, Gokhan
The study aimed at the metabolite profiling and evaluation of antioxidant and enzyme inhibitory properties of methanol extracts from flowers, leaves, and tubers of unexplored Eminium intortum (Banks & Sol.) Kuntze and E. spiculatum (Blume) Schott (Araceae). A total of 83 metabolites, including 19 phenolic acids, 46 flavonoids, 11 amino, and 7 fatty acids were identified by UHPLC-HRMS in the studied extracts for the first time. E. intortum flower and leaf extracts had the highest total phenolic and flavonoid contents (50.82 ± 0.71 mg GAE/g and 65.08 ± 0.38 RE/g, respectively). Significant radical scavenging activity (32.20 ± 1.26 and 54.34 ± 0.53 mg TE/g for DPPH and ABTS) and reducing power (88.27 ± 1.49 and 33.13 ± 0.68 mg TE/g for CUPRAC and FRAP) were observed in leaf extracts. E. intortum flowers showed the maximum anticholinesterase activity (2.72 ± 0.03 mg GALAE/g). E. spiculatum leaves and tubers exhibited the highest inhibition towards α-glucosidase (0.99 ± 0.02 ACAE/g) and tirosinase (50.73 ± 2.29 mg KAE/g), respectively. A multivariate analysis revealed that O-hydroxycinnamoylglycosyl-C-flavonoid glycosides mostly accounted for the discrimination of both species. Thus, E. intortum and E. spiculatum can be considered as potential candidates for designing functional ingredients in the pharmaceutical and nutraceutical industries.
AtıfScopus15OpenAlex11İncele - MakaleYalnız künye2023Scopus SJRQ1Latent heat thermal energy storage in a shell-tube design: Impact of metal foam inserts in the heat transfer fluid side
Ghalambaz, Mehdi; Sheremet, Mikhail; Raizah, Zehba; Akkurt, Nevzat; Ghalambaz, Mohammad
The improvement of heat transfer in latent heat thermal energy storage (LHTES) system is a crucial task. In the current study, the impact of diverse metal foam (MF) layer arrangements on heat transfer fluid (HTF) within a shell-tube LHTES is explored. Six distinct cases (A-F) with varied MF coverage percentages and layer dimensions were assessed. The local thermal non-equilibrium model was utilized to take into account the PCM and MF temperatures. The finite element method was used for solving the partial differential equations. The impact of MF configurations and inlet pressures (250 Pa, 500 Pa, and 750 Pa) on the thermal energy storage/release was addressed. Cases A-C, featuring a 50 % MF concentration, exhibit shorter melting times than Cases D–F, with decreasing MF concentrations. A higher MF concentration improves the melting process due to increased thermal conductivity and lower thermal resistance on the HTF side. Cases D–F, with a centralized MF layer and decreasing concentrations from 25 % to 6.25 %, display progressively shorter melting times, suggesting that a lower MF concentration leads to more efficient melting. Solidification times also decrease with increasing inlet pressures across all cases. Reynolds numbers, influenced by average HTF tube outlet velocity, vary substantially across cases and inlet pressure differences. Cases A-C demonstrate similar Reynolds numbers for each inlet pressure difference, while Cases D–F show a more pronounced increase in Reynolds numbers as the MF layer is reduced and flow resistance drops. Cases A (50 % MF layer) and F (6.5 % MF layer) provide the quickest charging and discharging times due to their unique combination of MF layer properties and inlet pressures. The study highlights the need to consider MF layer composition and inlet pressure when designing optimal LHTES systems for efficient energy storage/release.
AtıfScopus11WoS10OpenAlex11İncele - MakaleAçık Erişim2023Phycoremediation of Thallium Toxic Metal Present in Gallery Water of an Abandoned Mine Area by Algae Cladophora fracta
Topal, Murat; Arslan Topal, E. Işıl; Öbek, Erdal
In this study, phycoremediation of thallium toxic metal present in galery water of an abandoned mine area was investigated by using Cladophora fracta. Within the scope of the study, a reactor containing Cladophora fracta was used and it was determined whether the Cladophora fracta accumulated thallium depending on time. Additionally, the bioconcentration factor was calculated. According to research findings; the accumulations of thallium by Cladophora fracta, compared with uncontaminated alga, were 225% at 5 min, 450% at 10 min, 550% at 20 min, 575% at 40 min, 700% at 60 min, and 900% at 120 min, respectively. BCF values were between 1000-5000. This indicated that Cladophora fracta had bioaccumulation potential. As a result, this research carried out in mining area has documented the phycoremediation of thallium in gallery water of an abandoned mine area.
