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Articles 31 - 60 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Synthesis Of 3-Methyl-3-Buten-1-Ol By Supercritical Co2 In Coordination With Hzsm-5 Catalyzed Formaldehyde-Isobutene Prins Reaction, Hang Yuan, Gui-Ping Cao, Hui Lv
Synthesis Of 3-Methyl-3-Buten-1-Ol By Supercritical Co2 In Coordination With Hzsm-5 Catalyzed Formaldehyde-Isobutene Prins Reaction, Hang Yuan, Gui-Ping Cao, Hui Lv
Turkish Journal of Chemistry
The reaction solvent and catalyst play an essential role in the Prins reaction for the synthesis of 3-methyl-3-buten-1-ol (MBO) from formaldehyde and isobutene. The reactivity of the solid base catalyzed Prins condensation reaction by formaldehyde and isobutene in supercritical CO2 was investigated using CsH2PO4 modified HZSM-5. We finds that the alkaline sites of the alkali-loaded catalyst can extract the α-H on isobutene to generate olefin carbon negative ions, while the supercritical CO2 with weak Lewis acidity can activate formaldehyde to carbon positive ions, which can combine more easily with the carbon negative isobutene to react, thus improving the reactivity of …
Magnetic Solid-Phase Extraction Technique Based On Fe3o4@Coppy-Pth Nanocomposite For Extraction Of Cobalt, Chromium, And Nickel Prior To Determination By Micro-Sample Injection System-Flame Atomic Absorption Spectrometry In Alcoholic And Nonalcoholic Beverages, Meli̇ke Küçüksakalli, Qamar Salamat, Buket Ti̇reli̇, Şükrü Gökhan Elçi̇
Magnetic Solid-Phase Extraction Technique Based On Fe3o4@Coppy-Pth Nanocomposite For Extraction Of Cobalt, Chromium, And Nickel Prior To Determination By Micro-Sample Injection System-Flame Atomic Absorption Spectrometry In Alcoholic And Nonalcoholic Beverages, Meli̇ke Küçüksakalli, Qamar Salamat, Buket Ti̇reli̇, Şükrü Gökhan Elçi̇
Turkish Journal of Chemistry
A novel Fe3O4@coPPy-PTH nanocomposite-based sorbent was prepared via in-situ oxidative polymerization using Fe3O4 nanoparticles with spherical and flower-like morphologies of thiophene and pyrrole as the feedstocks. The synthesized nanocomposite utilized sensitive extraction and determination of the metal ions Co(II), Cr(III), and Ni(II) without a chelating agent, followed by a micro-sample injection system-flame atomic absorption spectrometer (MIS-FAAS). The composition and morphology of Fe3O4@coPPy-PTH nanocomposite were characterized by advanced spectroscopic and imaging techniques like SEM and FT-IR. SEM observations showed the size of Fe3O4 nanoparticles changed from 30 nm to 120 nm in diameter after the copolymer (PPy-PTH) coating. The Fe3O4@coPPy-PTH nanocomposite …
Β-Ketoenamine-Linked Covalent Organic Framework For Efficient Iodine Capture, Onur Büyükçakir
Β-Ketoenamine-Linked Covalent Organic Framework For Efficient Iodine Capture, Onur Büyükçakir
Turkish Journal of Chemistry
Exploring the materials that effectively capture radioactive iodine is crucial in managing nuclear waste produced from nuclear power plants. Herein, a β-ketoenamine-linked covalent organic framework (bCOF) was reported as an effective adsorbent to capture iodine from both vapor and solution. bCOF's high porosity and heteroatom-rich skeleton offer a notable iodine vapor uptake capacity of up to 2.51 g g-1 at 75 oC under ambient pressure. Furthermore, after five consecutive adsorption-desorption cycles, the bCOF demonstrates a high reusability performance with a significant iodine vapor capacity retention. The adsorption mechanism was also investigated using various ex-situ structural characterization techniques, and these mechanistic …
Lacoo3 Is A Promising Catalyst For Dry Reforming Of Benzene Used As A Surrogate Of Biomass Tar, Başar Çağlar, Deni̇z Üner
Lacoo3 Is A Promising Catalyst For Dry Reforming Of Benzene Used As A Surrogate Of Biomass Tar, Başar Çağlar, Deni̇z Üner
Turkish Journal of Chemistry
Tar build-up is one of the bottlenecks of biomass gasification process. Dry reforming of tar is an alternative solution if oxygen chemical potential on the catalyst surface is at sufficient levels. For this purpose, an oxygen donor perovskite, LaCoO3, was used as a catalyst for dry reforming of tar. To circumvent the complexity of the tar and its constituents, benzene molecule was chosen as a model compound. Dry reforming of benzene vapour on the LaCoO3 catalyst was investigated at temperatures of 600, 700, 800 °C, at the CO2/C6H6 ratios of 3, 6, 12 and at space velocities of 14000 and …
Identification Of Blood At Simulated Crime Scenes Using Silver Nanoparticles With Sers, Uğur Köroğlu, Necdet Sağlam, Uğur Tamer, Ramazan Akcan, İsmai̇l Hakki Boyaci, Eylül Evran
Identification Of Blood At Simulated Crime Scenes Using Silver Nanoparticles With Sers, Uğur Köroğlu, Necdet Sağlam, Uğur Tamer, Ramazan Akcan, İsmai̇l Hakki Boyaci, Eylül Evran
Turkish Journal of Chemistry
Analysis of substances and samples obtained from the crime scene are very important in solving forensic cases. In order to determine the variables involved in a crime and to expedite the investigation process, especially the rapid analysis of body fluids in a small quantity and within an environment containing diverse components is necessary. For this reason, it is of great importance to analyse biological fluids with rapid, non-chemical contamination, non-destructive, low-cost and accurate techniques. In recent years, with advancements in laser technology, spectroscopic methods have been introduced as an analytical technique in forensic medicine and chemical studies. This study focuses …
Synthesis And Photooxygenation Of 3-(P-Substituted Phenyl)-3a,8a-Dihydro-4h-Cyclohepta[D]Isoxazoles: Facial Selectivity, Mahi̇re Emel Olgun, Abdullah Menzek, Ertan Şahi̇n, Yasi̇n Çeti̇nkaya
Synthesis And Photooxygenation Of 3-(P-Substituted Phenyl)-3a,8a-Dihydro-4h-Cyclohepta[D]Isoxazoles: Facial Selectivity, Mahi̇re Emel Olgun, Abdullah Menzek, Ertan Şahi̇n, Yasi̇n Çeti̇nkaya
Turkish Journal of Chemistry
Two 3-(p-substituted phenyl)-3a,8a-dihydro-4H-cyclohepta[d]isoxazoles were synthesized by 1,3-dipolar cycloaddition of the corresponding nitrile oxides with cycloheptatriene. Two endoperoxides were synthesized as facially selective and single products in high yields (93-95%) from the reactions of isoxazole derivatives with singlet oxygen. The exact configurations of the endoperoxide with a methyl group in the phenyl ring and the diol synthesized from it were confirmed by X-ray analysis. To elucidate the mechanism, the formation energy of the endoperoxide was investigated by simulations using the software package Gaussian 09 and density functional theory calculations via the M06-2X/6-311+G(d,p) level method in dichloromethane. The results were consistent with …
Corrigendum To “Polybrominated Methoxy- And Hydroxynaphthalenes” [Turkish Journal Of Chemistry 40 (2) 2016 332-346 ], Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç
Corrigendum To “Polybrominated Methoxy- And Hydroxynaphthalenes” [Turkish Journal Of Chemistry 40 (2) 2016 332-346 ], Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç
Turkish Journal of Chemistry
This corrigendum is to address an issue regarding the manuscript’s previous publication. The authors have regrettably noticed that the incorrect version of the figure and crystal data was used in the original published version of this paper. To rectify this oversight and ensure the accuracy of the published work the correct figure and data are included for your reference.
Link to the original article: https://journals.tubitak.gov.tr/chem/vol40/iss2/11/
Efficient Deep Neural Network Compression For Environmental Sound Classification On Microcontroller Units, Shan Chen, Na Meng, Haoyuan Li, Weiwei Fang
Efficient Deep Neural Network Compression For Environmental Sound Classification On Microcontroller Units, Shan Chen, Na Meng, Haoyuan Li, Weiwei Fang
Turkish Journal of Electrical Engineering and Computer Sciences
Environmental sound classification (ESC) is one of the important research topics within the non-speech audio classification field. While deep neural networks (DNNs) have achieved significant advances in ESC recently, their high computational and memory demands render them highly unsuitable for direct deployment on resource-constrained Internet of Things (IoT) devices based on microcontroller units (MCUs). To address this challenge, we propose a novel DNN compression framework specifically designed for such devices. On the one hand, we leverage pruning techniques to significantly compress the large number of model parameters in DNNs. To reduce the accuracy loss that follows pruning, we propose a …
Network Intrusion Detection Based On Machine Learning Strategies: Performance Comparisons On Imbalanced Wired, Wireless, And Software-Defined Networking (Sdn) Network Traffics, Hi̇lal Hacilar, Zafer Aydin, Vehbi̇ Çağri Güngör
Network Intrusion Detection Based On Machine Learning Strategies: Performance Comparisons On Imbalanced Wired, Wireless, And Software-Defined Networking (Sdn) Network Traffics, Hi̇lal Hacilar, Zafer Aydin, Vehbi̇ Çağri Güngör
Turkish Journal of Electrical Engineering and Computer Sciences
The rapid growth of computer networks emphasizes the urgency of addressing security issues. Organizations rely on network intrusion detection systems (NIDSs) to protect sensitive data from unauthorized access and theft. These systems analyze network traffic to detect suspicious activities, such as attempted breaches or cyberattacks. However, existing studies lack a thorough assessment of class imbalances and classification performance for different types of network intrusions: wired, wireless, and software-defined networking (SDN). This research aims to fill this gap by examining these networks’ imbalances, feature selection, and binary classification to enhance intrusion detection system efficiency. Various techniques such as SMOTE, ROS, ADASYN, …
Enrichment Of Turkish Question Answering Systems Using Knowledge Graphs, Okan Çi̇ftçi̇, Fati̇h Soygazi̇, Selma Teki̇r
Enrichment Of Turkish Question Answering Systems Using Knowledge Graphs, Okan Çi̇ftçi̇, Fati̇h Soygazi̇, Selma Teki̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Recent capabilities of large language models (LLMs) have transformed many tasks in Natural Language Processing (NLP), including question answering. The state-of-the-art systems do an excellent job of responding in a relevant, persuasive way but cannot guarantee factuality. Knowledge graphs, representing facts as triplets, can be valuable for avoiding errors and inconsistencies with real-world facts. This work introduces a knowledge graph-based approach to Turkish question answering. The proposed approach aims to develop a methodology capable of drawing inferences from a knowledge graph to answer complex multihop questions. We construct the Beyazperde Movie Knowledge Graph (BPMovieKG) and the Turkish Movie Question Answering …
A New Approach: Ordinal Predictive Maintenance With Ensemble Binary Decomposition (Opmeb), Ozlem Ece Yurek, Derya Birant
A New Approach: Ordinal Predictive Maintenance With Ensemble Binary Decomposition (Opmeb), Ozlem Ece Yurek, Derya Birant
Turkish Journal of Electrical Engineering and Computer Sciences
Predictive maintenance (PdM), a fundamental element of modern industrial systems, employs machine learning to monitor equipment conditions, estimate failure probabilities, and optimize maintenance schedules. Its core objective is to enhance equipment reliability, extend lifespan, and minimize costs through data-driven insights by enabling efficient maintenance scheduling, reducing downtime, and optimizing resource allocation. In this paper, we propose a novel ordinal predictive maintenance with ensemble binary decomposition (OPMEB) method for the PdM domain, considering the hierarchical nature of class labels reflecting the machine's health status, including categories like healthy, low risk, moderate risk, and high risk. The proposed OPMEB method was validated …
A Real-Time Embedded System Designed For Nilm Studies With A Novel Competitive Decision Process Algorithm, Sai̇d Mahmut Çinar, Rasi̇m Doğan, Emre Akarslan
A Real-Time Embedded System Designed For Nilm Studies With A Novel Competitive Decision Process Algorithm, Sai̇d Mahmut Çinar, Rasi̇m Doğan, Emre Akarslan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper explores the determination of any load or load combination in a power system at any moment. This process requires measurements at the main electric utility service entry of a house, known as nonintrusive measurement. To accurately identify loads, total harmonic distortion, RMS, third harmonic currents, and power consumption are considered their fingerprints. Based on these fingerprints, an algorithm called the competitive decision process is developed and integrated into an embedded system. This algorithm has a two-level decision mechanism. In the first stage, the winner loads with the highest similarity scores from each feature are determined, and the loads …
Ensemble Learning For Accurate Prediction Of Heart Sounds Using Gammatonegram Images, Sinam Ashinikumar Singh, Sinam Ajitkumar Singh, Aheibam Dinamani Singh
Ensemble Learning For Accurate Prediction Of Heart Sounds Using Gammatonegram Images, Sinam Ashinikumar Singh, Sinam Ajitkumar Singh, Aheibam Dinamani Singh
Turkish Journal of Electrical Engineering and Computer Sciences
The analysis of heart sound signals constitutes a pivotal domain in healthcare, with the prediction of imbalanced heart sounds offering critical diagnostic insights. However, the inherent diversity in cardiac sound patterns presents a substantial challenge in predicting imbalanced signals. Many scientific disciplines have focused a great deal of emphasis on the problem of class inequality. We introduce an ensemble learning approach employing a convolutional neural network model-based deep learning algorithm to effectively tackle the challenges associated with predicting imbalanced heart sound signals. We use a Gammatone filter bank to extract relevant features from the heard sound signal. Our approach leverages …
Multi-Label Voice Disorder Classification Using Raw Waveforms, Gökay Di̇şken
Multi-Label Voice Disorder Classification Using Raw Waveforms, Gökay Di̇şken
Turkish Journal of Electrical Engineering and Computer Sciences
Automated voice disorder systems that distinguish pathological voices from healthy ones have been developed with the aid of machine learning methods. Both clinicians and patients can benefit from these systems as they provide many advantages, compared to the invasive techniques. These systems can produce binary (healthy/pathological) or multi-class (healthy/selected pathologies) decisions. However, multiple disorders might exist in an individual’s voice. Multi-label classification should be considered in such cases. By this time, only a single report is available on this topic, where hand-crafted features were used, and a data augmentation technique was utilized to overcome class imbalances. In this study, a …
Detection And Classification Of Unauthorized Use Of Irrigation Motors In Agricultural Irrigation, Önder Ci̇velek, Sedat Görmüş, Hali̇l İbrahi̇m Okumuş, Orhan Gazi̇ Kederoglu
Detection And Classification Of Unauthorized Use Of Irrigation Motors In Agricultural Irrigation, Önder Ci̇velek, Sedat Görmüş, Hali̇l İbrahi̇m Okumuş, Orhan Gazi̇ Kederoglu
Turkish Journal of Electrical Engineering and Computer Sciences
The decarbonisation of electricity generation requires the real-time monitoring and control of grid components in order to efficiently and timely dispatch demand. This highly automated system, known as the Smart Grid, relies on smart or sensor-equipped distribution network components to optimise energy flow and minimise losses. However, energy theft, a major obstacle to efficient resource utilisation, poses a significant challenge to achieving this goal. This study proposes and evaluates a real-time telemetry and control system designed to mitigate energy theft in agricultural irrigation applications. The system increases energy efficiency by tracking the energy use in agricultural irrigation. The key challenge …
A New Dynamic Classifier Selection Method For Text Classification, İsmai̇l Terzi̇, Alper Kürşat Uysal
A New Dynamic Classifier Selection Method For Text Classification, İsmai̇l Terzi̇, Alper Kürşat Uysal
Turkish Journal of Electrical Engineering and Computer Sciences
The primary objective of employing multiple classifier systems (MCS) in pattern recognition is to enhance classification accuracy. Dynamic classifier selection (DCS) and dynamic ensemble selection (DES) are two purposeful forms of multiple classifier systems. While DES involves the selection of a classifier set followed by decision combination, DCS opts for the choice of a single competent classifier, eliminating the necessity for classifier combination. As a consequence, DCS methods exhibit superior efficiency in terms of processing time and memory usage compared to DES methods. Moreover, a substantial performance gap exists between the performance of Oracle and both DES and DCS methods. …
Early Frasnian (Upper Devonian) Genundewa Event In The Bolshaya Nadota River Section Of The Subpolar Urals (Russia), Marina Soboleva, Denis Gruzdev, Dmitry Sobolev, Andrey Zhuravlev
Early Frasnian (Upper Devonian) Genundewa Event In The Bolshaya Nadota River Section Of The Subpolar Urals (Russia), Marina Soboleva, Denis Gruzdev, Dmitry Sobolev, Andrey Zhuravlev
Turkish Journal of Earth Sciences
Evidence of the Frasnian Genundewa Event at the FZ 2 – FZ 3 boundary interval has been detected in the facies of the isolated carbonate platform in Subpolar Urals. The preserved traces of the Genundewa Event represent micritic microlaminated carbonates, which manifests a short-term deepening episode in an extremely shallow water background. From the onset of this deep-water deposition there is a dominance of Polygnathus, Ancyrodella, and Mesotaxis whereas in the underlying shallow water deposits, the genus Polygnathus clearly predominated. No specific features of the Genundewa Event were observed in the C-isotope record. The mean δ13Ccarb value is approximately 2‰ …
Tectonic Geomorphology Of The South-Eastern Section Of The Burdur-Fethiye Shear Zone, Western Taurides: Morphotectonic Framework Of The Eşen Basin, İrem Eli̇tez, Cenk Yaltirak
Tectonic Geomorphology Of The South-Eastern Section Of The Burdur-Fethiye Shear Zone, Western Taurides: Morphotectonic Framework Of The Eşen Basin, İrem Eli̇tez, Cenk Yaltirak
Turkish Journal of Earth Sciences
The Eşen Basin is a transtensional basin located in the south-eastern section of the Burdur-Fethiye Shear Zone and includes a part of the Western Taurides to the east. This tectonically complex area is bounded by the back-arc region of the Hellenic Arc, the offshore Anaximander Mountains, the offshore Rhodes and Finike basins, the extensional Western Anatolian region, and the compressional regions of the Western Taurides. In this study, in order to characterise the recent tectonic activity of the Eşen Basin, 101 drainage basins and 41 mountain fronts were analysed in terms of the longitudinal river profiles and the application of …
Eocene Magmatism Related To Postcollisional Extension In The Eastern Pontides (Ne Türkiye): 40ar-39ar Geochronology, Geochemistry, And Whole-Rock Sr-Nd-Pb-Hf Isotopes, Emre Aydinçakir, Cem Yücel, Abdullah Kaygusuz, Özgür Bi̇li̇ci̇, Si̇nan Yilmazer, Gilles Ruffet
Eocene Magmatism Related To Postcollisional Extension In The Eastern Pontides (Ne Türkiye): 40ar-39ar Geochronology, Geochemistry, And Whole-Rock Sr-Nd-Pb-Hf Isotopes, Emre Aydinçakir, Cem Yücel, Abdullah Kaygusuz, Özgür Bi̇li̇ci̇, Si̇nan Yilmazer, Gilles Ruffet
Turkish Journal of Earth Sciences
The mineral chemistry, whole-rock geochemistry, 40Ar / 39Ar dating and Sr-Nd-Pb-Hf isotopes of the Eocene Narman (Erzurum) Volcanic rocks in the southeast of the Eastern Pontides Orogenic Belt (EPOB, NE Türkiye) were investigated. The Narman Volcanites consist of basaltic dyke, basaltic lava, and basaltic volcanic breccia facies. Volcanites contain plagioclase (An34-80), clinopyroxene (Wo38-47En41-50Fs5-18), and olivine (Fo68-90) as phenocrystals with magnetite/titanomagnetite microphenocrysts. New 40Ar-39Ar ages suggest that these volcanic rocks erupted between 44.5 ± 0.1 and 43.4 ± 0.1 Ma, within the Middle Eocene (Lutetian). Narman Volcanites have calc-alkaline character, with medium-high K content. Volcanites are enriched in large ion lithophile …
Evaluation Of Gis-Based Spatial Interpolation Methods For Groundwater Level: A Case Study Of Türkiye, Ni̇lüfer Ti̇rol Kirçi̇çek, Alper Baba, Ayhan Koçbay, Murat Mert Toklu
Evaluation Of Gis-Based Spatial Interpolation Methods For Groundwater Level: A Case Study Of Türkiye, Ni̇lüfer Ti̇rol Kirçi̇çek, Alper Baba, Ayhan Koçbay, Murat Mert Toklu
Turkish Journal of Earth Sciences
Groundwater is a valuable and universally distributed resource on Earth. Understanding the spatial and temporal dynamics of groundwater is of utmost importance for effective management. Normally, groundwater levels are recorded at arbitrary points, but groundwater modeling requires interpolating the measured values at specific grid nodes. The aim of this study was to identify and evaluate the geographical variations of groundwater levels in Türkiye using three geostatistical interpolation techniques. Data from 355 groundwater wells from 1970 to 2019 were used for this purpose. In addition, an investigation of changes in annual average temperature and precipitation was conducted for two different time …
Facies Architecture And Depositional Evolution Of The Middle Eocene Mass Flow-Dominated Fan Delta Complex In The Multifeeder Areas: Elazığ Marine Basin (Eastern Türkiye), Onur Alkaç
Turkish Journal of Earth Sciences
The mass flow-dominated fan delta complex is developed by the rapid deposition of coarse-grained materials in front of uplifted areas under the influence active tectonism. This is important for providing clues about the first opening stages of marine basins. The study aims to shed light on the fact that mass flow-dominated fan delta complexes play an active role in determining the characterization of tectonism controlling basin opening. In the study area, mass flow-dominated deposits of the Deliktaş Fan Delta Complex (DFDC) represent the first deposits of the southern part of the Middle Eocene Elazığ Marine Basin, whose development is controlled …
Properties Of Gyrogroups Induced By Groups Whose Central Quotients Being 2-Engel, Jaturon Wattanapan, Teerapong Suksumran
Properties Of Gyrogroups Induced By Groups Whose Central Quotients Being 2-Engel, Jaturon Wattanapan, Teerapong Suksumran
Turkish Journal of Mathematics
A group Γ is said to be CCII if the quotient Γ/Z(Γ) is 2-Engel or, equivalently, commutator-inversion invariant, where Z(Γ) is the center of Γ. In this article, we prove algebraic and topological properties of gyrogroups that are induced by CCII groups. Then, using a classification of non-abelian groups of order n with n < 32, we determine all finite CCII groups of order less than 32.
Positive And Decreasing Solutions For Higher Order Caputo Boundary Valueproblems With Sign-Changing Green’S Function, Rian Yan, Yige Zhao, Xuan Leng, Yabing Li
Positive And Decreasing Solutions For Higher Order Caputo Boundary Valueproblems With Sign-Changing Green’S Function, Rian Yan, Yige Zhao, Xuan Leng, Yabing Li
Turkish Journal of Mathematics
In this paper, Caputo boundary value problems of order 3 < ζ ≤ 4 are investigated on the interval [0, 1] .By Guo-Krasnoselskii fixed point theorem, some criteria of existence and multiplicity of positive and decreasing solutionsare established. The main novelty of the paper lies in its capability to achieve positive solutions while the correspondingGreen’s function changes sign. Finally, two examples are provided to illustrate the application of these results.
On Vietoris’ Hybrid Number Sequence, Nurten Gürses, Gülsüm Yeli̇z Saçli, Sali̇m Yüce
On Vietoris’ Hybrid Number Sequence, Nurten Gürses, Gülsüm Yeli̇z Saçli, Sali̇m Yüce
Turkish Journal of Mathematics
This work is intended to establish a relation between Vietoris’ sequence, which is a rational sequence, andhybrid numbers. Then it provides some characteristic properties of the hybrid numbers with Vietoris’ number coefficients.Some relations between this hybrid number and its norm, the recurrence relations, the generating function, Binet-likeformula and Catalan-like identities are also indicated. Furthermore, a determinantal approach is presented to obtainelements of Vietoris’ hybrid number sequence.
Stacks In Einstein Gravity, Kadri̇ İlker Berktav
Stacks In Einstein Gravity, Kadri̇ İlker Berktav
Turkish Journal of Mathematics
In this paper, we examine stacky structures in certain Einstein gravity theories. In brief, using the classicalformulation of (vacuum) gravity, with vanishing cosmological constant, we first construct the stack of solutions to Einsteinfield equations on any given fixed manifold. Using a similar approach and setup, we also study Einstein’s gravity onfamilies of manifolds and define another stack encoding this situation. Later on, we focus on the gauge theoreticalinterpretation of 3D gravity and provide a natural stack associated with that interpretation. Finally, in a particularsetup, we give a natural morphism between the two stacks arising from different descriptions of 3D gravity.
The Flow-Geodesic Curvature And The Flow-Evolute Of Spherical Curves, Mircea Crasmareanu
The Flow-Geodesic Curvature And The Flow-Evolute Of Spherical Curves, Mircea Crasmareanu
Turkish Journal of Mathematics
We introduce and study a deformation of the geodesic curvature for a given spherical curve γ . Also, wedefine a new type of evolute and two Fermi-Walker type derivatives for γ . Some concrete examples are detailed with aspecial attention towards space curves with a constant torsion.
Some Qualitative Results For Nonlocal Dynamic Boundary Value Problem Of Thermistor Type, Svetlin G. Georgiev, Mahammad Khuddush, Sanket Tikare
Some Qualitative Results For Nonlocal Dynamic Boundary Value Problem Of Thermistor Type, Svetlin G. Georgiev, Mahammad Khuddush, Sanket Tikare
Turkish Journal of Mathematics
This paper is concerned with second-order nonlocal dynamic thermistor problem with two-point boundary conditions on time scales. By utilizing the fixed point theorems due to Schaefer and Rus, we establish some sufficient conditions for the existence and uniqueness of solutions. Further, we discuss the continuous dependence of solutions and four types of Ulam stability. We provide examples to support the applicability of our results.
Curves As Slant Submanifolds Of An Almost Product Riemannian Manifold, Pablo Alegre, Alfonso Carriazo
Curves As Slant Submanifolds Of An Almost Product Riemannian Manifold, Pablo Alegre, Alfonso Carriazo
Turkish Journal of Mathematics
In this paper, we show that in an almost product manifold there exist curves that are slant submanifolds. Wecharacterize these curves and study them in two and three-dimensional locally product manifolds. Finally, we constructcurves in a hypersurface of a Kaehler manifold.
Bernstein-Nikol’Skii-Markov-Type Inequalities For Algebraic Polynomials In Aweighted Lebesgue Space In Regions With Cusps, Uğur Değer, Fahreddi̇n Abdullayev
Bernstein-Nikol’Skii-Markov-Type Inequalities For Algebraic Polynomials In Aweighted Lebesgue Space In Regions With Cusps, Uğur Değer, Fahreddi̇n Abdullayev
Turkish Journal of Mathematics
In this paper, we study Bernstein-Nikol’skii-Markov type inequalities for arbitrary algebraic polynomials withrespect to a weighted Lebesgue space, where the weight functions have some singularities on a given contour. We considercurves which can contain a finite number of exterior and interior corners with power law tangency of the boundary arcs atthose points where the weight functions have both zeros and poles of finite order. The estimates are given for the growthof the module of derivatives for algebraic polynomials on the closure of a region bounded by a given curve, dependingon the behavior of weight functions, on the property of curve, …
New Oscillation Criteria For First-Order Differential Equations With General Delay Argument, Emad R. Attia, Irena Jadlovska
New Oscillation Criteria For First-Order Differential Equations With General Delay Argument, Emad R. Attia, Irena Jadlovska
Turkish Journal of Mathematics
This paper is concerned with the oscillation of solutions to a class of first-order differential equations withvariable coefficients and a general delay argument. New oscillation criteria are established, which improve and extendmany known results reported in the literature. A couple of illustrative examples are given to show the efficiency of thenewly obtained results. In particular, it is shown that our criteria partially fulfill a remaining gap in a recent sharp resultby Pituk et al. [31].