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Full-Text Articles in Physical Sciences and Mathematics

Accelerated Iron Valence Cycling In Fenton System Using Activated Hydrogen Enhanced By Mil-100(Fe) Modified By Nano-Pd0 Particle, Yun-Dong Wang, Yi-Jun Chen, Mei-Na Cheng, Xin Liu Dec 2023

Accelerated Iron Valence Cycling In Fenton System Using Activated Hydrogen Enhanced By Mil-100(Fe) Modified By Nano-Pd0 Particle, Yun-Dong Wang, Yi-Jun Chen, Mei-Na Cheng, Xin Liu

Turkish Journal of Chemistry

In this paper, a novel Fenton reaction system which was called MHACF-MIL-100(Fe) was constructed. In this system, based on active hydrogen-accelerated FeIII reduction, the hydroxyl radical was continuously produced with a trace amount of total iron. The MIL-100(Fe) modified with the nano-Pd0 particle could be used to activate the H2. Under normal temperature and pressure, the target organic pollutants, such as sulfamethazine and 4-chloro phenol, could be degraded fast. In the condition of initial aqueous solution pH 3, 2 g L–1 dosage of MIL-100(Fe) catalyst loaded with nano-Pd0, Pd/MIL-100(Fe), 20 mM 30 wt% hydrogen peroxide, 25 μM ferrous chloride and …


Phytochemical Investigation On The Aerial Parts Of Veratrum Versicolor F. Viride Nakai And Their Biological Activities, Seong Su Hong, Jae Yeon Lee, Yeon Woo Jeong, Ji Eun Lee, Yun-Hyeok Choi, Wonsik Jeong, Eun-Kyung Ahn, Chun Whan Choi, Il Ho Ahn, Joa Sub Oh Dec 2023

Phytochemical Investigation On The Aerial Parts Of Veratrum Versicolor F. Viride Nakai And Their Biological Activities, Seong Su Hong, Jae Yeon Lee, Yeon Woo Jeong, Ji Eun Lee, Yun-Hyeok Choi, Wonsik Jeong, Eun-Kyung Ahn, Chun Whan Choi, Il Ho Ahn, Joa Sub Oh

Turkish Journal of Chemistry

Veratrum spp. have traditionally been used in folk medicine to treat various pathologies. In this study, nine compounds, comprising one simple phenolic compound (1), three stilbenoids (2–4), and five flavonoids (5–9), were isolated from the aerial parts of Veratrum versicolor f. viride Nakai. The structures of these compounds were elucidated by spectroscopic analyses and comparison with reported data. Together, all reported compounds were isolated from V. versicolor f. viride for the first time in the study. Among them, two flavone aglycone tricetins (7 and 9) have never been isolated from the genus Veratrum or the family Melanthiaceae. The ethanol extract …


Sustainable Graphitic Carbon From Biomass To Be Suitable For Technological Devices, Gökçen Akgül Dec 2023

Sustainable Graphitic Carbon From Biomass To Be Suitable For Technological Devices, Gökçen Akgül

Turkish Journal of Chemistry

Technological devices are mostly manufactured by conductive and semiconductive materials. As advancement in the last decades, carbon nanomaterials have been explored in electrical/electronic technology due to their unique performances for manufacturing developing, and prudential miniaturized and flexible electrical/electronic devices. In the era of sustainable and clean carbon technology; renewable, alternative, biodegradable, and eco-friendly new carbon resources are required. Biomass could be the answer to offer inspiring carbon allotropes from nature to be suitable for developing electrical/electronic devices. In this article, deriving of the technological carbonaceous material from biomass, studies although they are very limited in the literature on obtaining the …


Quaternized Chitosan/Pva/Natural Bioactive Agent Electrospun Wound Scaffolds: Production, Characterization, And Investigation Of Release Kinetics, Ezgi Eren Belgin, Cankiz Gi̇zem Deli̇balta Dec 2023

Quaternized Chitosan/Pva/Natural Bioactive Agent Electrospun Wound Scaffolds: Production, Characterization, And Investigation Of Release Kinetics, Ezgi Eren Belgin, Cankiz Gi̇zem Deli̇balta

Turkish Journal of Chemistry

Quaternized chitosan (HTCC) was synthesized and characterized to increase chitosan solubility. Then HTCC was electrospun with poly (vinyl alcohol) (PVA) and prepared natural bioactive agent (Calendula officinalis) extract was loaded onto fibers for wound scaffold applications. Morphological, structural, and mechanical characterization of the produced wound scaffolds was performed and their in vitro bioactive component release behavior was investigated. As a result, it was observed that the degree of quaternization of chitosan was 0.89, and synthesized HTCC was soluble in acidic, basic, alkaline media and could be electrospun with PVA in the presence of a natural bioactive agent. The presence of …


Synthesis Of Silane- And Quaternary Ammonium-Bearing Copolymers And Application As A Coating Resin On Cotton Fabric, Ayşe Marti̇n, Nazgül Güler, İlknur Yerli̇, Hande Hançer, Tüli̇n Özbek, Tarik Eren Dec 2023

Synthesis Of Silane- And Quaternary Ammonium-Bearing Copolymers And Application As A Coating Resin On Cotton Fabric, Ayşe Marti̇n, Nazgül Güler, İlknur Yerli̇, Hande Hançer, Tüli̇n Özbek, Tarik Eren

Turkish Journal of Chemistry

In this study, silane and quaternary ammonium functional methacrylate monomers were synthesized and used to construct a copolymer using an emulsion polymerization technique to control the reaction rate. The copolymer was then designed using different ratios of silane and quaternary ammonium groups to investigate the relationship between the structure and properties. The presence of the ethoxy silane group in the copolymer series provided covalent bonding through the silanol group onto cotton fabric. The presence of cationic groups also helped to cover the fabric surface. After coating the cotton textile fabric, the resistance of the dye on the fabric surface to …


Polypyrrole Fabricated Laponite Rd Conductive Nanocomposites: Influence Of Grafting Efficiency On Structural And Conductive Properties, Shafiq Ur Rehman, Shaista Taimur, Asif Raza, Tariq Yasin Dec 2023

Polypyrrole Fabricated Laponite Rd Conductive Nanocomposites: Influence Of Grafting Efficiency On Structural And Conductive Properties, Shafiq Ur Rehman, Shaista Taimur, Asif Raza, Tariq Yasin

Turkish Journal of Chemistry

In the present work novel conductive organic-inorganic nanocomposites were produced by grafting of pyrrole monomer onto silanized Laponite RD utilizing emulsion graft polymerization. Influence of some important factors like concentration of monomer, initiator and surfactant were investigated on grafting efficiency. Grafting of polypyrrole chains onto modified Laponite RD was verified by Fourier transform infrared spectroscopy (FT-IR). Scanning electron microscope (SEM) revealed the spherical particles of nanocomposite with average diameter of 271.5 nm. XRD pattern showed that molecular framework of pure polypyrrole almost remains same in nanocomposite. Surface area and pore volume of Laponite RD, measured by Brunauer-Emmett-Teller (BET) analysis, was …


Optimum Pyrolysis Conditions To Prepare The Most Crystalline Boron Carbide Powder From Boric Acid–Mannitol Complex Ester, Abdullah Devri̇m Pekdemi̇r, Müşerref Önal, Yüksel Sarikaya Dec 2023

Optimum Pyrolysis Conditions To Prepare The Most Crystalline Boron Carbide Powder From Boric Acid–Mannitol Complex Ester, Abdullah Devri̇m Pekdemi̇r, Müşerref Önal, Yüksel Sarikaya

Turkish Journal of Chemistry

A weak acidic complex ester (CE) in solid form was prepared by a condensation reaction between very weak boric acid (BA: H3BO3) and (D)-mannitol (MA: C6H14O6) by the molar ratio of BA/MA = 2. A boron carbide (B4C) precursor was obtained from heating of the CE at 400 °C for 4 h. The precursor was pyrolyzed under argon flow in the interval of 1300–1550 °C for 4 h and at 1400 °C for 1–4 h, respectively. The materials were examined using several techniques such as X-ray diffraction analysis, thermal analysis, scanning electron microscopy, particle size distribution, and nitrogen adsorption/desorption. The …


Exploring The Photocatalytic And Photodynamic Effects Of Bodipy-Linked Titanium Dioxide Nanoparticles, Seda Demi̇rel Topel Dec 2023

Exploring The Photocatalytic And Photodynamic Effects Of Bodipy-Linked Titanium Dioxide Nanoparticles, Seda Demi̇rel Topel

Turkish Journal of Chemistry

This study aimed to investigate the photocatalytic and photodynamic actions of a 2,6-diiodinated-BODIPY (2,6-diI2-Bod) photosensitizer (PS) covalently linked to TiO2 nanoparticles (NPs). The TiO2 NPs were synthesized utilizing the hydrothermal technique, yielding an average particle size of 4–5 nm as ascertained by transmission electron microscopy and 6.4 nm as determined by dynamic light scattering measurements. The integration of the nonsoluble Bod PS to TiO2 NPs provided increased dispersibility in physiological media, making it more applicable to photodynamic therapy applications. Bod-TiO2 NPs exhibited moderate efficiency of 56.9% in singlet oxygen generation. Additionally, the photocatalytic behavior of the TiO2 NPs was evaluated …


Scope And Limitations Of The Preparation Of Xanthones Using Eaton’S Reagent, Johann Bosson Dec 2023

Scope And Limitations Of The Preparation Of Xanthones Using Eaton’S Reagent, Johann Bosson

Turkish Journal of Chemistry

Xanthones comprise a large family of heterocycles displaying fascinating biological properties. Many synthetic protocols have been developed for the preparation of natural and nonnatural xanthone derivatives. Among them, condensation reactions between salicylic acid derivatives and phenol partners are highly desirable. Those reactions can be satisfactorily performed using Eaton’s reagent (P2O5 in CH3SO3H). Despite being highly effective with a variety of substrates, this approach presents limitations that depend on the electronic nature of the reaction precursors. The scope and limitations of the Eaton’s reagent-mediated preparation of xanthones are herein presented and discussed. In short, this approach is limited to the utilization …


Comparison Of Metal-Carbenoid Reactions Of Β-2-Five-Membered Heteroaryl Substituted Α,Β-Unsaturated Ketones, Kumsal Eroğlu, Olcay Anaç, Füsun Şeyma Kişkan Dec 2023

Comparison Of Metal-Carbenoid Reactions Of Β-2-Five-Membered Heteroaryl Substituted Α,Β-Unsaturated Ketones, Kumsal Eroğlu, Olcay Anaç, Füsun Şeyma Kişkan

Turkish Journal of Chemistry

In this study, β-2-heteroaryl substituted (N-methyl 2-pyrrolyl, 2-thiophenyl, 2-furyl) α,β-unsaturated ketones were reacted with two α-diazo carbonyl compounds that had different characteristics (dimethyl diazo malonate and 1-diazo-1-phenyl-propane-2-one) in the presence of both copper and rhodium catalysts. In the case of reactions with N-methyl 2-pyrrolyl α,β-unsaturated ketones, the major product was the insertion derivative. However, in the reactions of 2-thiophenyl and 2-furyl α,β-unsaturated ketones with dimethyl diazomalonate (acceptor-acceptor disubstituted), only dihydrofuran products were formed over carbonyl ylides. When 2-thiophenyl and 2-furyl α,β-unsaturated ketones were reacted with 1-diazo-1-phenyl-propane-2-one (donor-acceptor disubstituted), 1-phenylpropane-1,2-dione was obtained under our reaction conditions.


Photophysical, Thermal, And Dft Studies On A Tetraaryl-Azadipyrromethene Ligand And Its Zinc(Ii) Complex, Gökhan Sevi̇nç Dec 2023

Photophysical, Thermal, And Dft Studies On A Tetraaryl-Azadipyrromethene Ligand And Its Zinc(Ii) Complex, Gökhan Sevi̇nç

Turkish Journal of Chemistry

An azadipyrromethene ligand (H1) and homoleptic zinc(II) (H1-Zn) complex were synthesized. The resulting structures were elucidated by NMR, FTIR, and HRMS techniques. The photophysical properties and effects of complexing the zinc(II) atom to azadipyrromethene ligands in solution were studied by means of UV-Vis absorption and fluorescence spectroscopy. Experimental findings were elucidated using density functional theory computations and interfragment charge transfer (IFCT) and electron-hole analyses. The fluorescence features were found to be negligible. The ligand molecule decayed at a rate of 3% while the complex decayed at 2% upon photoirradiation based on photostability experiments. The singlet oxygen quantum yields of the …


Bromination And Conversion Of Tetrahydro-1h-Indene To Bisoxirane With A New Approach: Synthesis, Structural Characterization By Spectroscopic And Theoretical Methods, And Biological Analysis Supported By Dft And Docking, Raşi̇t Fi̇kret Yilmaz, Sultan Erkan, Sali̇h Ökten, Ahmet Tutar, Ertan Şahi̇n Dec 2023

Bromination And Conversion Of Tetrahydro-1h-Indene To Bisoxirane With A New Approach: Synthesis, Structural Characterization By Spectroscopic And Theoretical Methods, And Biological Analysis Supported By Dft And Docking, Raşi̇t Fi̇kret Yilmaz, Sultan Erkan, Sali̇h Ökten, Ahmet Tutar, Ertan Şahi̇n

Turkish Journal of Chemistry

In this study, a new method for synthesizing diepoxides is proposed. Tetrahydroindene 1 was brominated with NBS in the presence of LiClO4 and acetic acid, resulting in the formation of dibromodiacetate derivatives 2 and 3. Treatment of compounds 2 and 3 with NaOH in methanol produced a mixture of diepoxides 4 and 5. Additionally, direct bromination of tetrahydro-1H-indene yielded tetrabromo octahydroindene isomers 6 and 7. The structures of the compounds were characterized using spectroscopic techniques such as 1H NMR, 13C NMR, APT, COSY, and XRD. The new method provides an easy and selective route to access epoxides for the synthesis …


Intercalation Of Pyrazolone-Based Oxalamide Metal Complexes Into Na-Montmorillonite For Catalytic Liquid-Phase Oxidation Of Phenol Using H2o2, Serhat Uzan, Eyüp Başaran Dec 2023

Intercalation Of Pyrazolone-Based Oxalamide Metal Complexes Into Na-Montmorillonite For Catalytic Liquid-Phase Oxidation Of Phenol Using H2o2, Serhat Uzan, Eyüp Başaran

Turkish Journal of Chemistry

The intercalation of pyrazolone-based oxalamide metal complexes into Na-montmorillonite (Na-MMT) for catalytic liquid-phase oxidation of phenol using H2O2 was undertaken by a flexible ligand method using metal ions including Mn(II), Zn(II), and Sn(II). First, the metal ions were exchanged with the sodium ions of Na-MMT, and then these metal ions were complexed with a new pyrazolone-based oxalamide ligand. The intercalated metal complexes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental analysis, and thermogravimetric analysis. Phenol was successfully oxidized by heterogeneous catalysts based on Mn(II), Zn(II), and Sn(II) pyrazolone-based oxalamide complexes intercalated into …


Production Of Gelatin Fibrous Mats Using Different Nanofiber Production Methods For Medical Applications And Comparison Of Their Properties, Melike Güngör, Kevser Sağlamkol, Zeynep Yağmur Baydemi̇r, Ali̇ Kiliç Dec 2023

Production Of Gelatin Fibrous Mats Using Different Nanofiber Production Methods For Medical Applications And Comparison Of Their Properties, Melike Güngör, Kevser Sağlamkol, Zeynep Yağmur Baydemi̇r, Ali̇ Kiliç

Turkish Journal of Chemistry

In the literature, there are studies on medical applications using different nanofiber production methods with natural polymers. However, each system has different fiber-forming capabilities. For this reason, in this study, we investigated the production of nanofibers from a biodegradable natural polymer, gelatin, using four separate nanofiber production methods, namely electrospinning (ES), electroblowing (EB), solution blowing (SB), and centrifugal spinning (CS). Our aim was to determine the most suitable fibrous web structure for medical applications and contribute to science in this respect. It was observed that the thinnest fibers (386 nm) and the heaviest mats (15.975 g m–2) were produced by …


Extraction/Transportation Of Co2+ Metal Ions With Bis(2-Ethylhexyl) Phosphate Dissolved In Kerosene Using A Multidropped Liquid Membrane Technique, Volkan Demi̇rel, Ramazan Donat Dec 2023

Extraction/Transportation Of Co2+ Metal Ions With Bis(2-Ethylhexyl) Phosphate Dissolved In Kerosene Using A Multidropped Liquid Membrane Technique, Volkan Demi̇rel, Ramazan Donat

Turkish Journal of Chemistry

The transport properties of Co2+ ions from the aqueous donor phase to aqueous acceptor phase with the recently developed multidroplet liquid membrane (MDLM) extraction system were studied. This system serves as a continuous process for the transportation of ions and requires fewer reagents for starting and conducting the procedure. Moreover, the procedure results in fewer waste chemicals and mixtures in comparison to traditional extraction methods. During extraction, bis(2-ethylhexyl) phosphate (D2EHPA) was used as a carrier material and 5% potassium thiocyanate (KSCN) solution was used to obtain a colored complex for UV-Vis detection. By means of several experiments, the optimum D2EHPA …


Poly(Vinyl Alcohol)/Zsm-5 Zeolite Mixed Matrix Membranes For Pervaporation Dehydration Of Ethanol And N-Propanol, Ji Ting Wang, Zhen Huang, Ya Tong Zhu, Si Ning Wang Dec 2023

Poly(Vinyl Alcohol)/Zsm-5 Zeolite Mixed Matrix Membranes For Pervaporation Dehydration Of Ethanol And N-Propanol, Ji Ting Wang, Zhen Huang, Ya Tong Zhu, Si Ning Wang

Turkish Journal of Chemistry

In this study, mixed matrix membranes (MMMs) composed of poly(vinyl alcohol) (PVA) and porous ZSM-5 zeolite are thoroughly investigated for concentrating alcohols of ethanol and n-propanol via dewatering pervaporation. The effects of the zeolite content (10–30 wt.%), feed composition (5–30 wt.% water), and feed temperature (50–90 °C) on the pervaporation flux/separation factor and component permeance/selectivity of these MMMs are examined in detail. These MMMs achieve higher separation efficiency and pervaporation flux than their pure PVA counterparts as expected, even if the dehydration results strongly depend on the pervaporation conditions. The disparity in pervaporation performances acquired for different alcohol solutions may …


Synthesis And Singlet Oxygen Generation Of Boron- 2-(4,5-Dibromo-1h-Imidazole-2-Yl)-3,5-Dipyrazolopyridine Complex For Antimicrobial Photodynamic Therapy, Zeynep Ekmekçi̇, Seda Karaoğlu Dec 2023

Synthesis And Singlet Oxygen Generation Of Boron- 2-(4,5-Dibromo-1h-Imidazole-2-Yl)-3,5-Dipyrazolopyridine Complex For Antimicrobial Photodynamic Therapy, Zeynep Ekmekçi̇, Seda Karaoğlu

Turkish Journal of Chemistry

In this study, the pyridine side of a boron 2-(2'-pyridyl) imidazole (BOPIM) core, which has very few derivatives synthesized in the literature and can show fluorescence properties in solid form, was derivatized with 1-methylpyrazole, predicted to have activity against fungi or bacteria according to the literature. Additionally, its imidazole side was brominated to increase the efficiency of singlet oxygen production by increasing the intersystem crossing. The photophysical properties of the new synthesized BOPIM derivative were investigated in general organic solvents with different polarities. While the wavelength of the maximum absorbance was determined as 406 nm in CH2Cl2 and THF, the …


Removal Of Toxic Cr(Vi) From Aqueous Medium With Effective Magnetic Carbon-Based Nanocomposites, Ferda Ci̇van Çavuşoğlu, Gülsüm Özçeli̇k, Şahi̇ka Sena Bayazi̇t Dec 2023

Removal Of Toxic Cr(Vi) From Aqueous Medium With Effective Magnetic Carbon-Based Nanocomposites, Ferda Ci̇van Çavuşoğlu, Gülsüm Özçeli̇k, Şahi̇ka Sena Bayazi̇t

Turkish Journal of Chemistry

Cr(VI), which has toxic effects, is a heavy metal and it must be removed from the environment due to the various damages it causes. In this study, the removal of Cr(VI) pollutants from aqueous solutions with Fe3O4-based materials using a batch adsorption technique was investigated. Magnetically modified graphene nanoplatelet (GNP)-based nanocomposites were prepared and their structures were characterized by FTIR, XRD, SEM, BET, and TGA techniques. The effects of various physicochemical parameters such as adsorbent dose, contact time, initial Cr(VI) solution concentration, pH, and the presence of coexisting ions (NaCl) on the adsorption process were investigated. Accordingly, the optimum conditions …


Ph Responsive Curcumin Released From Urea-Amine Group Functionalized Mesoporous Organosilica Nanoparticles, Osman Tayyar Arli, Yaşar Gök, Hali̇l Zeki̇ Gök Dec 2023

Ph Responsive Curcumin Released From Urea-Amine Group Functionalized Mesoporous Organosilica Nanoparticles, Osman Tayyar Arli, Yaşar Gök, Hali̇l Zeki̇ Gök

Turkish Journal of Chemistry

Studies on natural products with anticancer properties have gained more importance in recent years in order to not damage healthy tissues during cancer treatments or to perform the treatment causing the least damage. Curcumin is a common natural product with anticancer properties, but its low solubility, instability, and bioavailability have limited its use in clinical applications in cancer research. As a proposed solution to this problem, a new mesoporous organosilica nanocarrier (MON-A) functionalized with a 1,2-diphenylethane-1,2-diamine structure capable of pH-controlled release was prepared in this study. MON-A was characterized by TGA, BET, XRD, FT-IR, and SEM-EDS analyses. Dispersion of MON-A …


Machine Learning Based Bioinformatics Analysis Of Intron Usage Alterations And Metabolic Regulation In Adipose Browning, Hamza Umut Karakurt, Pinar Pi̇r Nov 2023

Machine Learning Based Bioinformatics Analysis Of Intron Usage Alterations And Metabolic Regulation In Adipose Browning, Hamza Umut Karakurt, Pinar Pi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Adipose tissue is the major energy depot of the body and is considered an endocrine organ. Adipose tissue involves many different cell types, first and foremost, the adipocytes. White adipose cells that store fat and brown adipocytes that take part in lipid oxidation and heat generation are the most common cell types in adipose tissue. Even though brown adipocytes which have a high number of mitochondria and high fat-burning capacity are rare in adults, they are abundant in newborns and rodents. White adipocytes can gain a temporal brown-like character with a process called browning, which can be induced with cold …


Fuzzycsampling: A Hybrid Fuzzy C-Means Clustering Sampling Strategy For Imbalanced Datasets, Abdullah Maraş, Çi̇ğdem Erol Nov 2023

Fuzzycsampling: A Hybrid Fuzzy C-Means Clustering Sampling Strategy For Imbalanced Datasets, Abdullah Maraş, Çi̇ğdem Erol

Turkish Journal of Electrical Engineering and Computer Sciences

Classification model with imbalanced datasets is recently one of the most researched areas in machine learning applications since they induce to the emergence of low-performing machine learning models. The imbalanced datasets occur if target variables have an uneven number of examples in a dataset. The most prevalent solutions to imbalanced datasets can be categorized as data preprocessing, ensemble techniques, and cost-sensitive learning. In this article, we propose a new hybrid approach for binary classification, named FuzzyCSampling, which aims to increase model performance by ensembling fuzzy c-means clustering and data sampling solutions. This article compares the proposed approaches' results not only …


A Novel Computing Scheme Based On Pattern Matching For Identification Of Nephron Loss And Chronic Kidney Disease Stage, Rehan Ahmad, Basant Mohanty Nov 2023

A Novel Computing Scheme Based On Pattern Matching For Identification Of Nephron Loss And Chronic Kidney Disease Stage, Rehan Ahmad, Basant Mohanty

Turkish Journal of Electrical Engineering and Computer Sciences

Nephrons are the basic filtering units of the kidneys. Progression of chronic kidney disease (CKD) destroys nephrons permanently. Although there are many computing schemes suggested in recent years to identify CKD stages, no computing method has been suggested for identifying the nephron loss within kidney regions during CKD progression. In this paper, a novel pattern matching-based computation scheme is proposed to detect nephron loss in the kidney regions during CKD progression. We consider image registration (IR) with different transforms and a structural similarity index algorithm (SSIM) to match patterns of ultrasound images of kidney regions to identify the nephron loss. …


New Modified Carrier-Based Level-Shifted Pwm Control For Npc Rectifiers Considered For Implementation In Ev Fast Chargers, Merve Mollahasanoğlu, Hakki Mollahasanoğlu, Hali̇l İbrahi̇m Okumuş Nov 2023

New Modified Carrier-Based Level-Shifted Pwm Control For Npc Rectifiers Considered For Implementation In Ev Fast Chargers, Merve Mollahasanoğlu, Hakki Mollahasanoğlu, Hali̇l İbrahi̇m Okumuş

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the aim is to evaluate three-phase (3?) AC/DC neutral point-clamped (NPC) power factor corrected (PFC) multilevel converter performance for electric vehicle (EV) fast chargers. Power factor correction for EV fast chargers is very important in terms of efficient power usage and charger compatibility with the grid. Multilevel converters improve charging efficiency, reduce voltage stresses on components, minimize electromagnetic interference, and support high power capabilities. For this reason, multilevel converters with the PFC feature contribute to the reliable and effective operation of the fast-charging infrastructure. Rectifier analysis is tested with extensive simulations using a new modified carrier-based level-shifted …


A Comparative Study Of Blind Source Separation Methods, Burak Baysal, Mehmet Önder Efe Nov 2023

A Comparative Study Of Blind Source Separation Methods, Burak Baysal, Mehmet Önder Efe

Turkish Journal of Electrical Engineering and Computer Sciences

Blind source separation is a popular research topic used for decomposing mixed signals, particularly in the field of music. In addition to exploring machine learning-based approaches, this study aims to examine the performance of classical algorithms in separating audio signal sources. The evaluation of different genres is a significant aspect of this study as the performance of the methods may vary across various musical genres and different audio components. This consideration provides a novel perspective and contributes to a comprehensive analysis of the algorithms. Using the MusDB-HQ dataset, we conducted experimental studies comparing classical algorithms, including FastICA, NMF, and DUET, …


A Comparative Study Of Yolo Models And A Transformer-Based Yolov5 Model For Mass Detection In Mammograms, Damla Coşkun, Dervi̇ş Karaboğa, Alper Baştürk, Bahri̇ye Akay, Özkan Ufuk Nalbantoğlu, Serap Doğan, İshak Paçal, Meryem Altin Karagöz Nov 2023

A Comparative Study Of Yolo Models And A Transformer-Based Yolov5 Model For Mass Detection In Mammograms, Damla Coşkun, Dervi̇ş Karaboğa, Alper Baştürk, Bahri̇ye Akay, Özkan Ufuk Nalbantoğlu, Serap Doğan, İshak Paçal, Meryem Altin Karagöz

Turkish Journal of Electrical Engineering and Computer Sciences

Breast cancer is a prevalent form of cancer across the globe, and if it is not diagnosed at an early stage it can be life-threatening. In order to aid in its diagnosis, detection, and classification, computer-aided detection (CAD) systems are employed. You Only Look Once (YOLO)-based CAD algorithms have become very popular owing to their highly accurate results for object detection tasks in recent years. Therefore, the most popular YOLO models are implemented to compare the performance in mass detection with various experiments on the INbreast dataset. In addition, a YOLO model with an integrated Swin Transformer in its backbone …


Charge Transfer Evaluation In Solid Insulating Materials Encapsulating The Gaseous Voids Of Submillimeter Dimensions Using Transmission Line Method, Amin Shamsi, Alireza Ganjovi, Amir Abas Shayegani Akmal Nov 2023

Charge Transfer Evaluation In Solid Insulating Materials Encapsulating The Gaseous Voids Of Submillimeter Dimensions Using Transmission Line Method, Amin Shamsi, Alireza Ganjovi, Amir Abas Shayegani Akmal

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, using a lumped RC circuit model which is based on transmission line modeling (TLM) method, the charge transfer in a solid insulating system encapsulating a gaseous void of submillimeter dimensions is evaluated. Here, both the dielectric material and gaseous void are considered simultaneously as a transmission line. The transmission line includes the capacitive and resistance elements and, the obtained circuit equations were coupled with the continuity and kinetic energy equations for charged species along with Poisson's equation. These equations are solved via 4th order Runge-Kutta method and, the electric field and potential, density of all the charged …


Lsav: Lightweight Source Address Validation In Sdn To Counteract Ip Spoofing-Based Ddos Attacks, Ali̇ Karakoç, Fati̇h Alagöz Nov 2023

Lsav: Lightweight Source Address Validation In Sdn To Counteract Ip Spoofing-Based Ddos Attacks, Ali̇ Karakoç, Fati̇h Alagöz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a design to detect and prevent IP spoofing-based distributed denial of service (DDoS) attacks on software-defined networks (SDNs). DDoS attacks are still one of the significant problems for internet service providers (ISPs) and individual users. These attacks can disrupt customer services by targeting the availability of the system, and in some cases, they can completely shut down the target infrastructure. Protecting the system against DDoS attacks is therefore crucial for ensuring the reliability and availability of internet services. To address this problem, we propose a lightweight source address validation (LSAV) framework that leverages the flexibility …


Exploring The Impact Of Training Datasets On Turkish Stance Detection, Muhammed Sai̇d Zengi̇n, Berk Utku Yeni̇sey, Mücahi̇d Kutlu Nov 2023

Exploring The Impact Of Training Datasets On Turkish Stance Detection, Muhammed Sai̇d Zengi̇n, Berk Utku Yeni̇sey, Mücahi̇d Kutlu

Turkish Journal of Electrical Engineering and Computer Sciences

Stance detection has garnered considerable attention from researchers due to its broad range of applications, including fact-checking and social computing. While state-of-the-art stance detection models are usually based on supervised machine learning methods, their effectiveness is heavily reliant on the quality of training data. This problem is more prevalent in stance detection task because the stance of a text is intimately tied to the target under consideration. While numerous datasets exist for stance detection, determining their suitability for a specific target can be challenging. In this work, we focus on Turkish stance detection and explore the impact of training data …


A Practical Low-Dimensional Feature Vector Generation Method Based On Wavelet Transform For Psychophysiological Signals, Erdem Erkan, Yasemi̇n Erkan Nov 2023

A Practical Low-Dimensional Feature Vector Generation Method Based On Wavelet Transform For Psychophysiological Signals, Erdem Erkan, Yasemi̇n Erkan

Turkish Journal of Electrical Engineering and Computer Sciences

High-dimensional feature vectors entail computational cost and computational complexity. However, a successful classification can be obtained with an optimally sized feature vector consisting of distinctive features. With the widespread use of the internet and mobile devices, the need for systems with low computational costs is increasing day by day. In this study, starting from the idea that each motor imagery is represented as a subject-specific pattern in the brain, we propose a new and practical method that can generate a low-dimensional feature vector based on wavelet transform. The feature vector is obtained from the correlation between each trial and each …


Feature Selection Optimization With Filtering And Wrapper Methods: Two Disease Classification Cases, Serhat Ati̇k, Tuğba Dalyan Nov 2023

Feature Selection Optimization With Filtering And Wrapper Methods: Two Disease Classification Cases, Serhat Ati̇k, Tuğba Dalyan

Turkish Journal of Electrical Engineering and Computer Sciences

Discarding the less informative and redundant features helps to reduce the time required to train a learning algorithm and the amount of storage required, improving the learning accuracy as well as the quality of results. In this study, we present different feature selection approaches to address the problem of disease classification based on the Parkinson and Cardiac Arrhythmia datasets. For this purpose, first we utilize three filtering algorithms including the Pearson correlation coefficient, Spearman correlation coefficient, and relief. Second, metaheuristic algorithms are compared to find the most informative subset of the features to obtain better classification accuracy. As a final …