Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(82)
- Akkurt, Nevzat(67)
- Güler, Ömer(66)
- Baskonus, Haci Mehmet(62)
- Bulut, Hasan(60)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(43)
- Yildirim, Numan(42)
- Yildirim, Nuran Cikcikoglu(38)
- Paksoy, Mehmet Yavuz(36)
- Serdar, Osman(36)
- Zengin, Gokhan(36)
- Ince, Muharrem(34)
- Celik, Erkan(33)
- Benzer, Fulya(32)
- Kocabaş, Mehmet(30)
- Sulaiman, Tukur Abdulkadir(30)
- Tanyol, Mehtap(29)
- Yildirim, Ozal(28)
- Aslan, Naim(26)
- Kök, Mediha(26)
- Özkul, İskender(26)
- Ates, Mehmet(25)
- Danabas, Durali(25)
- Kutluyer, Filiz(25)
- Can, Erkan(24)
- Kutlu, Banu(23)
- Onat, Onur(23)
- Demir, Veysel(22)
- Erten, Fusun(22)
- Guler, Omer(22)
- Say, Yakup(22)
- Güler, Seval Hale(21)
- Yaman, Mehmet(21)
- Baykal, Duygu Sen(20)
- Sançar, Taylan(20)
- Susam, Selim Orhun(20)
- Cakilcioglu, Ugur(19)
- Orhan, Cemal(19)
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ3Functionalized and Ag-Loaded Nano-Delivery System for Doxorubicin: Loading, Controlled Release and Kinetic Studies
Aydogdu, Burcu; Kaplan Ince, Olcay; Ince, Muharrem; Unal, Ilkay
Multi-walled carbon nanotubes (fMWCNTs) that functionalized and loaded Ag nanoparticles (AgNPs) were investigated to adsorp doxorubicin hydrochloride (DXR). DXR release behavior efficiency was determined using kinetic studies. DXR agent was treated into fMWCNTs@AgNPs material with different drug loading rates. The material was successfully established and characterized using transmission electron microscopy, and fourier transform–infrared spectroscopy. Thermogravimetric analysis was performed to elucidate the effect of temperature on mass loss and X-ray diffraction analysis was systematically assessed the crystalline state of DXR. Various kinetic models including Higuchi, Baker Hixson-Crowell, and power-law were applied. It was revealed that DXR has more binding affinity to the fMWCNTs@AgNPs material system surface as a nanocarrier at pH 7.4 and showed more release at pH 5.0. Functionalized material confirmed its efficiency as pH-based drug delivery system. Used material can be utilized as promising nanocarriers, and findings will contribute to the rational design of novel delivery tools for drugs.
- DüzeltmeAçık Erişim2024Scopus SJRQ1Correction to: Influence of Plastic Deformation and Hydroxyapatite Coating on Structure, Mechanical, Corrosion, Antibacterial and Cell Viability Properties of Zinc Based Biodegradable Alloys (Metals and Materials International, (2024), 30, 12, (3320-3337), 10.1007/s12540-024-01710-z)
Aksakal, B.; Isın, Ege; Aslan, N.; Cihangir, S.; Sezek, S.; Yilmazer, Yasemin
In the original version of this article, co-author ‘Yasemin Yilmazer’ name was missed to add in the author group. The correct order of author names should read as ‘B. Aksakal · Ege Isın · N. Aslan · S. Cihangir · S. Sezek, Y. Yilmazer’. The affiliation details of Yasemin Yilmazer are ‘Department of Molecular Biology and Genetics Sabahattin Zaim University, Istanbul, Turkey yaseminyilmazer14@gmail.com’. The original article has been corrected.
- MakaleYalnız künye2024Scopus SJRQ2Uncovering chemical profiles, biological potentials, and protection effect against ECM destruction in H2O2-treated HDF cells of the extracts of Stachys tundjeliensis
Kurt-Celep, Inci; Zheleva-Dimitrova, Dimitrina; Sinan, Kouadio Ibrahime; Uba, Abdullahi Ibrahim; Nilofar; Mahomoodally, Mohamad Fawzi; Aumeeruddy, Muhammad Zakariyyah; Cakilcioglu, Ugur; Dall'Acqua, Stefano; Zengin, Gokhan
The genus Stachys L., one of the largest genera of the Lamiaceae family, is highly represented in Turkey. This study was conducted to determine the bio-pharmaceutical potential and phenolic contents of six different extracts from aerial parts of Stachys tundjeliensis. The obtained results showed that the ethanol extract exhibited the highest antioxidant activity in the antioxidant assays. Meanwhile, the ethanol extract displayed strong inhibitory activity against α-tyrosinase, the dichloromethane extract exhibited potent inhibition against butyrylcholinesterase, and the n-hexane extract against α-amylase. Based on ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry analysis, more than 90 secondary metabolites, including hydroxybenzoic acid, hydroxycinnamic acid, and their glycosides, acylquinic acids, phenylethanoid glycosides, and various flavonoids were identified or tentatively annotated in the studied S. tundjeliensis extracts. It was observed that the application of S. tundjeliensis eliminated H2O2-induced oxidative stress. It was determined that protein levels of phospho-nuclear factor kappa B (NF-κB), receptor for advanced glycation endproducts, and activator protein-1, which are activated in the nucleus, decreased, and the synthesis of matrix metalloproteinase (MMP)-2 and MMP-9 also decreased to basal levels. Overall, these findings suggest that S. tundjeliensis contains diverse bioactive compounds for the development of nutraceuticals or functional foods with potent biological properties.
AtıfScopus12OpenAlex12
İncele - MakaleYalnız künye2024Scopus SJRQ1Parental mediation in Turkey: The use of mobile devices in early childhood
Aslan, Alper; Turgut, Yigit Emrah
This study aims to investigate the use of mobile devices including smartphones and tablets in terms of mediation types of parents who have young children. In this case study, which is one of the qualitative research methods, criterion sampling was adopted for the selection of the study group. The fact that parents of 4–7-year-old children who use mobile devices is determined as the principal criterion. Twelve children aged 4–7 and their parents participated in the study. Data were collected through child observations and parent interviews. The results indicated that children with the mediation of parental supervision had fewer problematic behaviors in the use of media and faced fewer online risks. Besides, children whose parents have general restrictive mediation were the most likely to exhibit problematic media use behaviors. Children whose parents have active mediation were also the most likely to face Internet risks. It was observed that children frequently played games and watched videos on mobile devices. Most parents considered their children’s use of mobile devices as risky and harmful, while it was considered as useful only by co-using parents. It was found that children’s use of mobile devices causes physical, psychological, communicational, and cognitive issues while improving their academic abilities, interests, and cognitive structures. Nevertheless, it was discovered that parents used mobile devices to convince their children to go through their daily routines such as eating, bathing, and sleeping or calm them down in the workplace or social environments.
AtıfScopus9WoS8OpenAlex13İncele - MakaleYalnız künye2024Scopus SJRQ1Sharma–Mittal holographic dark energy and scalar field in Bianchi type-I cosmology
Korunur, Sibel
In this work, we studied Sharma–Mittal holographic dark energy model by considering Bianchi type-I cosmology. For this purpose we analyzed equation of state parameter using IR cutoff scale. Also it is reconstructed correspondence between Sharma–Mittal holographic dark energy and tachyon and quintessence scalar fields. Finally, we created plots for the time-evolution of the equation of state, kinetic energy, and scalar potential.
AtıfScopus3WoS4OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ2Optimizing the thermoelectric performance of Bi-Sb-Te thin films through compositional engineering
Yüzüak, Gizem Durak; Çetin, Mehmet; Yüzüak, Ercüment
The objective of the present investigation was to systematically investigate the structural and thermoelectric (TE) properties of BixSb2-xTe3 thin films with varying content of Bi. We investigated the impact of different atomic percentages of Bi (4, 6, 8 at. %) on the properties of carrier transport and TE performance. In general, the Seebeck coefficient remained consistent across the thin films. For the 8 at. % Bi thin film, the Seebeck coefficient and electrical conductivity were measured at 230 μV/K and 730 S/cm, respectively, at room temperature. These values were more than 20 times greater than the electrical conductivity observed in the thin films with compositions of 6 and 4 at. % Bi. As a result, the Bi-Sb-Te compound exhibited a TE power factor (PF) of 38x10−4 W/mK2 at 40 °C, surpassing the PFs observed in previous compositions. The analysis of surface microstructure, combined with atomic force microscopy and Kelvin probe microscopy images, revealed that the transport of carriers in films with high Bi content was impeded by the size of particles and scattering sites. On the other hand, an augmentation in Bi content promoted the transfer of charge through crystalline regions, hence improving the mobility of carriers and the total electrical conductivity. The aforementioned results emphasize the significant influence of Bi content on the electrical properties of semiconductors and demonstrate the effectiveness of compositional engineering based on Bi content in the development of TE materials with superior performance. The present study investigates the influence of Bi content on the electrical properties of Bi-Sb-Te thin films, demonstrating that compositional adjustments based on Bi content can impact the performance of TE materials. These findings contribute to the understanding of material optimization in the field of TE.
AtıfScopus4WoS5OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ1Integrating chemical analysis with in vitro, in silico, and network pharmacology to discover potential functional compounds from Marrubium astracanicum subsp. macrodon
Avşar, Ömer Kaan; Kasbolat, Sevgi; Ak, Gunes; Nilofar; Caprioli, Giovanni; Santanatoglia, Agnese; Uysal, Ahmet; Uba, Abdullahi Ibrahim; Ponniya, Sathish Kumar M.; Paksoy, Mehmet Yavuz
The members of the genus Marrubium are of great interest because they contain biologically active compounds. With in this mind, we aimed to examine the chemical profiles and biological activities (antioxidant, enzyme inhibition and antimicrobial effects) of different extracts of Marrubium astracanicum subsp. macrodon. Extractions of the plants were carried out with the solvent n-hexane, acetone, acetone/water (70 %), and water. The antioxidant activity of these extracts was evaluated through six different assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), metal chelating ability (MCA), and phosphomolybdenum (PBD). Additionally, the inhibitory effects of these solvents on five enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase were investigated. The study detected 38 compounds in a plant, with the highest content in acetone and acetone/water extracts. The acetone/water extract demonstrated the highest antioxidant activity aligning with its superior total phenolic (51.9 mg gallic acid equivalent (GAE)/g) and flavonoid (31.0 mg rutin equivalent (RE)/g) content, highlighting a direct correlation between bioactive compound concentration and antioxidant potential across various assays. Regarding the enzyme inhibition activity, the acetone/water extract of this plant exhibited significant AChE inhibition measuring 2.5 mg galantamine equivalent (GALAE)/g and anti-glucosidase activity measuring 1.2 mmol acarbose equivalent (ACAE)/g. In antimicrobial evaluation, the acetone extract exhibited good antimicrobial activity against B. cereus at 0.2 mg/ml dose. In molecular docking analysis, delphinidin 3,5 diglucoside showed a good interaction with the active site of AChE active. Through the application of network pharmacology, an in-depth exploration was conducted to unravel the potential of compounds from M. astracanicum against Alzheimer's disease. The study specifically focused on identifying key targets within the Alzheimer's disease pathway, pinpointing crucial proteins such as Glycogen synthase kinase-3 (GSK3), Prostaglandin-endoperoxide synthase 2 (PTGS2), and Alzheimer's-associated amyloid precursor protein (APP). In summary, the plant can serve as a valuable ingredient in the production of functional products within the pharmaceutical, nutraceutical, and cosmeceutical applications.
AtıfScopus4OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ2Cytotoxic, antioxidant, and enzyme inhibitory activities of Centaurea stapfiana extracts and their HPLC-ESI-QTOF-MS profiles: Insights into an unexplored Centaurea species
Zengin, Gokhan; Fernández-Ochoa, Álvaro; de la Luz Cádiz-Gurrea, María; Jiménez, Francisco-Javier Leyva; Uba, Abdullahi Ibrahim; Ak, Gunes; Soomro, Sanam Iram; Balos, Maruf; Cakilcioglu, Ugur; Rodrigues, Maria João
The members of the genus Centaurea have a great interest in pharmaceutical and nutraceutical fields due to their biological potential. Based on this information, we aimed to evaluate the biological properties (antioxidant, enzyme inhibition and cytotoxicity) and chemical profile of the extract of Centaurea stapfiana, an unstudied species. The highest total phenolic content was found in the ethanol/water extract with 32.17 mg GAE/g. A total of 102 of them were identified by HPLC-ESI-QTOF-MS analysis. These compounds were mainly hydroxybenzoic acid and hydroxycinnamic acid as well as flavonoids. In the antioxidant tests, the ethanol/water extract had the best free radical scavenging and reducing ability. However, in the enzyme inhibition test, the ethanol extract was the most active. The extracts were also tested on two tumour cell lines (RAW 264.7 and HepG2) and one non-tumour cell line (S17). The ethanol extract showed the promising effect on HepG2 (cell viability: 28.6 % at 50 g/ml). Furthermore, we examined the interactions between the compounds and enzymatic and cellular targets. A good interaction was found between quercetin-3-xylosyl-(1- > 6)-glucoside and iNOS. In summary, our results suggest that C. stapfiana can be considered as a versatile raw material for the development of health-promoting applications in the pharmaceutical and cosmeceutical fields.
AtıfScopus13OpenAlex14İncele - MakaleAçık Erişim2024Scopus SJRQ2The Behavior of Ceramic Fiber Geopolymer Concrete under the Effect of High Temperature
Dalğıç, Aras; Yılmazer Polat, Berivan
Geopolymer concrete (GC), also known as green concrete, contains slag, silica fume, and fly ash as binders. The absence of cement in concrete is critical to protect the world from the environmental impacts of cement production. In addition, exposure to high temperatures is a critical parameter that causes loss of strength in concrete. In this study, Geopolymer concrete samples were prepared with 10 different samples containing different proportions of slag, silica fume, and porous ash and subjected to various physical, mechanical, and optical tests. The sample (GS90) with optimum workability and compressive strength, which also showed high performance in water absorption, freeze-thaw, and UPV tests, was used in high-temperature tests. Portland cement concrete (PCC) was used as a control sample. This study investigated the effect of high temperatures on the physical and mechanical properties of fiber-free GCs containing 2%, 5%, and 10% by volume of ceramic fibers. Therefore, fiber-reinforced, fiber-free, and PCC specimens were subjected to high-temperature tests at 100, 300, 600, and 900 °C. As a result of the observation of crack growth, color changes, and compressive strength parameters in the samples subjected to high-temperature tests, the thermal resistance of the 10% ceramic fiber geopolymer concrete sample was 2.5% higher than other samples. There is no study in the literature that examines the behavior of ceramic fiber-reinforced geopolymer concrete at high temperatures. This research revealed an important finding by proving that ceramic fiber reinforcement increases the compressive strength of geopolymer concretes at a remarkable rate after high-temperature impact.
AtıfScopus8WoS10OpenAlex8İncele - DüzeltmeAçık Erişim2024Scopus SJRQ2Correction to: Detection of hateful twitter users with graph convolutional network model (Earth Science Informatics, (2023), 16, 1, (329-343), 10.1007/s12145-023-00940-w)
Utku, Anıl; Can, Umit; Aslan, Serpil
In this article the affiliation details for Serpil Aslan were incorrectly given as ‘Software Engineering Department, Turgut Üzal University, 44210 Malatya, Turkey’ but should have been ‘Department of Software Engineering, Faculty of Engineering and Natural Sciences, Malatya Turgut Ozal University, Malatya, Turkey.’ The original article has been corrected.
AtıfScopus1OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ2Combining chemical profiles and biological abilities of different extracts from Tanacetum nitens (Boiss. & Noë) Grierson using network pharmacology
Dall'Acqua, Stefano; Yagi, Sakina; Sut, Stefania; Uba, Abdullahi Ibrahim; Ponniya, Sathish Kumar M.; Koyuncu, Ismail; Toprak, Kenan; Balos, Mehmet Maruf; Kaplan, Alevcan; Çakılcıoğlu, Uğur
Tanacetum nitens (Boiss. & Noë) Grierson is an aromatic perennial herb used in Turkish traditional medicine to treat headache, fever, and skin diseases. This study aimed to investigate the chemical composition, antioxidant, enzyme inhibition, and cytotoxic properties of T. nitens aerial parts. Organic solvent extracts were prepared by sequential maceration in hexane, dichloromethane, ethyl acetate, and methanol while aqueous extracts were obtained by maceration or infusion. Nuclear magnetic resonance (NMR) and LC-DAD-MS analysis allowed the identification and quantification of different phytoconstituents including parthenolide, tanacetol B, tatridin B, quinic acid derivatives, β-sitosterol, and glycoside derivatives of quercetin and luteolin. The type and amount of these phytochemicals recovered by each solvent were variable and significant enough to impact the biological activities of the plant. Methanolic and aqueous extracts displayed the highest scavenging and ions-reducing properties while the dichloromethane and ethyl acetate extracts exerted the best total antioxidant activity and metal chelating power. Results of enzyme inhibition activity showed that the hexane, ethyl acetate, and dichloromethane extracts had comparable anti-acetylcholinesterase activity and the latter extract revealed the highest anti-butyrylcholinesterase activity. The best α-amylase and α-glucosidase inhibition activities were obtained from the hexane extract. The dichloromethane and ethyl acetate extracts exhibited the highest cytotoxic effect against the prostate carcinoma DU-145 cells. In conclusion, these findings indicated that T. nitens can be a promising source of biomolecules with potential therapeutic applications.
AtıfScopus7OpenAlex7İncele - DüzeltmeYalnız künye2024Scopus SJRQ1Retraction notice to “The influence of battery distance on a hybrid air-cooled cylindrical lithium-ion battery phase change material thermal management system for storing solar energy” [Journal of Energy Storage 52, Part B (2022) 104873] (Journal of Energy Storage (2022) 52(PB), (S2352152X22008805), (10.1016/j.est.2022.104873))
Akkurt, Nevzat; Aghakhani, S.; Mahmoud, Mustafa Z.; Tag El Din, ElSayed M.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). Please note that an Expression of Concern has previously been published to alert readers to an ongoing investigation into this paper. This retraction supersedes the Expression of Concern. This article has been retracted at the request of the editor. In investigating concerns brought up regarding the authenticity of the article, the editor reached out to the authors for an explanation. Furthermore, the editor discovered suspicious changes in authorship between the original submission and the revised version of this paper. In summary, the author names Nevzat Akkurt, Mustafa Z. Mahmoud and ElSayed M. Tag El Din were added to the revised paper without explanation and without exceptional approval by the editor, which is contrary to the journal policy on changes to authorship. The authors failed to provide a satisfactory explanation to the above points. The editor therefore feels that the findings of the manuscript cannot be relied upon and that the article needs to be retracted.
- DüzeltmeAçık Erişim2024Scopus SJRQ1Correction to: A Novel Secure S-box Design Methodology Based on FPGA and SHA-256 Hash Algorithm for Block Cipher Algorithms (Arabian Journal for Science and Engineering, (2024), 10.1007/s13369-024-09251-8)
Aydin, Yilmaz; Garipcan, Ali Murat; Özkaynak, Fatih
In the original publication, Table 1 was published with wrong values. The corrected table is given below. This has been updated in the original article. (Table presented.) 8 × 8 s-box component obtained through the proposed scheme 0 1 2 3 4 5 6 7 8 9 A B C D E F 0 7 16 40 37 222 29 204 225 65 81 156 199 63 42 44 197 1 158 2 11 117 30 134 106 209 24 78 152 141 215 251 160 36 2 249 6 228 75 233 198 132 203 147 100 176 97 214 43 239 59 3 146 47 200 49 79 195 188 201 184 85 218 151 213 154 76 253 4 17 196 26 120 105 130 45 115 186 4 224 145 118 252 138 208 5 255 10 5 129 236 91 21 162 216 109 72 27 243 207 89 13 6 124 86 206 179 192 172 235 68 28 230 74 54 99 80 139 143 7 182 234 108 149 94 168 177 3 64 250 46 41 9 191 232 136 8 84 210 88 205 23 15 95 56 50 83 107 190 98 242 103 19 9 60 169 101 181 114 174 69 82 119 112 247 244 128 51 96 1 A 123 90 150 93 32 159 57 237 170 52 231 202 125 217 155 73 B 189 31 66 14 194 62 227 104 140 165 153 131 20 12 211 245 C 111 102 183 142 137 113 187 254 133 77 116 122 161 110 38 173 D 39 18 87 148 175 121 35 193 70 229 92 55 166 219 163 171 E 185 8 126 135 127 223 240 58 53 22 248 246 167 67 48 212 F 241 144 221 178 220 34 71 0 61 164 180 157 226 238 25 33
AtıfScopus1İncele - MakaleAçık Erişim2024Scopus SJRQ4Comparative And Dynamic Analysis of Türkiye's Competitiveness in Unmanned Aerial Vehicles; [İnsansız Hava Araçlarında Türkiye’nin Rekabet Gücünün Karşılaştırmalı ve Dinamik Analizi]
Aydin, Üzeyir; Ateş, Erdem; Öztürk, Hasan
The study aims to determine the competitiveness of Türkiye’s UAV exports in a dynamic framework. The analysis used data from the first 20 countries with the largest share in the production and trade of products designated as UAVs by the Harmonic System six-digit and by the European Commission for 2012-2021. Within the scope of the study, it is determined that some countries have high competitiveness in 4 product groups examined with five different foreign trade indexes. It is concluded that Türkiye has strategic and dynamic superiority in two of the four product groups.
AtıfOpenAlex2TR Dizin1
İncele - MakaleYalnız künye2024Scopus SJRQ2CeO2/SWCNT nanocomposite coating: A novel approach for corrosion application
Doğan, Fatih
The coatings were prepared by blending different concentrations of SWCNTs and CeO2 particles with an epoxy resin by hydrothermal method, which was then applied to the substrate through the doctor blade technique. The mixtures were transferred into a 1-L capacity autoclave with a teflon-lined flange type and subjected to hydrothermal treatment at 100°C for 3 h. The surface coatings were applied using a doctor blade. Subsequently, the coated materials were placed in an oven and dried for 12 h at 50°C under vacuum conditions. The samples' structural analysis was examined through x-ray diffraction (XRD). XRD analysis verified the CeO2/SWCNT composite coating, and Fourier transform infrared spectroscopy (FTIR) was utilized to assess the presence of functional groups. Thermodynamic properties and thermal stability of composite coatings that were modified with SWCNTs and CeO2 particles were studied by thermogravimetric analysis (TGA). The impact of the CeO2/SWCNT composite on the anticorrosion capabilities of the epoxy coating was examined through electrochemical impedance spectroscopy (EIS), Nyquist curve, and Tafel slope characterization. Corrosion tests were conducted on the CeO2/SWCNT composite coatings in a 3.5 wt% sodium chloride (NaCl) solution at 25°C to improve corrosion resistance. The concentration of 0.4 wt% CeO2 was found to be optimal for achieving effective corrosion resistance. The composite coating CNT0.6-C0.4 exhibited significantly higher Ecorr (−426 V) and lower Icorr (2.96 × 10−6 A cm−2) values compared to samples from the CNT0, CNT0.2, and CNT0.6 groups. The paper presents a viable solution with CeO2/SWCNT composite coating for the engineering application of corrosive-inhibiting coatings.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2024Scopus SJRQ1Spread patterns of COVID-19 in European countries: hybrid deep learning model for prediction and transmission analysis
Utku, Anıl; Akcayol, M. Ali
The COVID-19 pandemic has profoundly impacted healthcare systems and economies worldwide, leading to the implementation of travel restrictions and social measures. Efforts such as vaccination campaigns, testing, and surveillance have played a crucial role in containing the spread of the virus and safeguarding public health. There needs to be more research exploring the transmission dynamics of COVID-19, particularly within European nations. Therefore, the primary objective of this research was to examine the spread patterns of COVID-19 across various European countries. Doing so makes it possible to implement preventive measures, allocate resources, and optimize treatment strategies based on projected case and mortality rates. For this purpose, a hybrid prediction model combining CNN and LSTM models was developed. The performance of this hybrid model was compared against several other models, including CNN, k-NN, LR, LSTM, MLP, RF, SVM, and XGBoost. The empirical findings revealed that the CNN-LSTM hybrid model exhibited superior performance compared to alternative models in effectively predicting the transmission of COVID-19 within European nations. Furthermore, examining the peak of case and death dates provided insights into the dynamics of COVID-19 transmission among European countries. Chord diagrams were drawn to analyze the inter-country transmission patterns of COVID-19 over 5-day and 14-day intervals.
AtıfScopus6WoS3OpenAlex7İncele - MakaleYalnız künye2024Scopus SJRQ3Using the Particle Swarm Optimization (PSO) Algorithm for Baseflow Separation and Determining the Trends for the Yesilirmak River (North Turkey)
Acar, R.; Saplioglu, K.
Estimation of baseflow is a complex hydrographic task. Baseflow techniques and coefficients vary from basin to basin, stream to stream, and year to year. In this study, meta-heuristic optimization is used to automatically identify baseflow. The Particle Swarm Optimization (PSO), a meta-heuristic optimization approach, is chosen. The constraint and cost functions were determined using the PSO algorithm, Lyne and Hollick techniques, and a computer application. Over the period 1980–2015, the data were collected at the Kale station in the Yesilirmak River basin to validate the study model. The results show that the hydrographs and baseflow dividing line were separated effectively. It has also been revealed that the PSO has a high speed as well as a high level of precision. In the research, in addition to the baseflow separation, the hydrograph, baseflow, and ratio of the baseflow to the streamflow at the station No. 1402 were assessed using the Mann–Kendall test and Innovative Trend Test (ITA), and as a result, their trends have been found. By the use of both of these methods, it has been shown that all parameters have an unfavorable trend. In addition, the research came to some other significant conclusions, such as the fact that the baseflow declines in tandem with the flow values and that the baseflow rates are low in years with high peak values of the hydrograph.
AtıfScopus4WoS5OpenAlex6İncele - MakaleYalnız künye2024Scopus SJRQ2Dynamic Analysis and Metallographic Examination of Linings with Different Composite Contents used in the Brakes of a Hydraulic Turbine
Işık, Erdem; Kahraman, Gökhan
The main aim of this study was to find ways to increase the performance and life of generator brake linings, which can lead to cost reduction and adequate downtime periods for hydroelectric power plants. First, the dynamic analysis of the linings used in hydraulic turbines was realized and their reactions were examined under different operating conditions. Second, two types of brake linings with different composite components produced in the market were examined metallographically and tested to determine both the stopping performance and durability time of the turbine-generator unit for a sufficient period of time in the vertical 150-megawatt Francis turbine with approximately 500 tons of rotary weight. As a result of these experiments, the lining with the boron component led to much better results than the other brake linings. It has been determined that the boron-containing lining makes 100 stops more than the other lining and stops 20 s earlier in one stop. Therefore, the use of a composite lining with boron content in the braking systems of hydroelectric power plants significantly reduces maintenance incidents and operation costs as it prolongs brake replacement periods in these plants. Graphical Abstract: (Figure presented.)
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ1An innovative approach in oat milk production: Ohmic heating
Ak, Ferit; Karakavuk, Emrah; Goksu, Ali; Sabancı, Serdal
This study aimed to produce oat-milk by using the ohmic heating (OH) system and to compare some quality properties of this milk with the milk produced by conventional methods. The solution containing oats was heated from 20 °C to 75 °C using 3 different voltage-gradients, and then oat-milk was obtained by applying a series of processes. It has been determined that as the voltage gradient increased during heating in oat milk production, the processing time shortens, and this time was 482 seconds in the conventional heating process. The effective electrical conductivity values increased as the temperature increased in the OH process during the production of oat-milk and these values vary between 0.13 and 0.41 S/m. Also, some quality characteristics of oat milk such as color and total phenolic content were better preserved in milk obtained by the OH process than conventional heating process. In addition, oat milk obtained by OH process had higher apparent viscosity at all temperatures.
AtıfScopus8WoS6OpenAlex8İncele - MakaleAçık Erişim2024Scopus SJRQ1Exploring Chemical Composition, Antioxidant, Enzyme Inhibitory and Cytotoxic Properties of Glaucium acutidentatum Hausskn. & Bornm. from Turkey Flora: A Novel Source of Bioactive Agents to Design Functional Applications
Yagi, Sakina; Zengin, Gokhan; Uba, Abdullahi Ibrahim; Maciejewska-Turska, Magdalena; Sieniawska, Elwira; Świątek, Łukasz; Rajtar, Barbara; Bahşi, Muammer; Guler, Osman; Dall’Acqua, Stefano
The present study was performed to determine the chemical constituents, cytotoxicity, antioxidant and enzyme inhibition activities of the aerial parts of Glaucium acutidentatum Hausskn. and Bornm. (family Papaveraceae). Methanolic and aqueous extracts were prepared by maceration, homogenizer-assisted extraction (HAE) and infusion. Results showed that the highest total phenolic and flavonoids contents were obtained from the methanol extracts obtained by HAE (53.22 ± 0.10 mg GAE/g) and maceration (30.28 ± 0.51 mg RE/g), respectively. The aporphine, beznyltetrahydroisoquinoline, and protopine types of Glaucium alkaloids have been tentatively identified. Among them, glaucine was identified in all extracts. Flavonoids, phenolic acids, coumarins, organic acids and fatty acids were also detected. Methanolic extract obtained using the HAE method displayed the highest anti-DPPH (41.42 ± 0.62 mg TE/g), total antioxidant (1.20 ± 0.17 mmol TE/g), Cu2+ (113.55 ± 6.44 mg TE/g), and Fe3+ (74.52 ± 4.74 mg TE/g) reducing properties. The aqueous extracts obtained by infusion and HAE methods exerted the best anti-ABTS (103.59 ± 1.49 mg TE/g) and chelating (19.81 ± 0.05 mg EDTAE/g) activities, respectively. Methanolic extract from HAE recorded the highest acetylcholinesterase (2.55 ± 0.10 mg GALAE/g) and α-amylase (0.51 ± 0.02 mmol ACAE/g) inhibition activities, while that obtained by maceration showed the best butyrylcholinesterase (3.76 ± 0.31 mg GALAE/g) inhibition activity. Both extracts revealed the best tyrosinase inhibitory activity (25.15 ± 1.00 and 26.79 ± 2.36 mg KAE/g, p ≥ 0.05). G. acutidentatum maceration-derived aqueous extract showed selective anticancer activity against cells originating from human hypopharyngeal carcinoma. In conclusion, these findings indicated that G. acutidentatum is a promising source of alkaloids and phenolic compounds for variable pharmaceutical formulations.
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