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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 Aug 2024

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 Aug 2024

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 Aug 2024

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/


Investigation Of Using Natural Deep Eutectic Solvents (Nades) For Extraction Of Bioactive Compounds From Aronia Melanocarpa Fruit, Melek Zor Aug 2024

Investigation Of Using Natural Deep Eutectic Solvents (Nades) For Extraction Of Bioactive Compounds From Aronia Melanocarpa Fruit, Melek Zor

Turkish Journal of Agriculture and Forestry

In this study, for the extraction of polyphenolic compounds found in high amounts in aronia fruit, three different extraction methods (classical, ultrasound, ultrasonic), three different traditional solvents (water, ethanol, acidified 80% methanol) as well as five different natural deep eutectic solvents (NADES) were used. Color indices as L*, a*, b*, C* and H° values, total phenolic, total flavonoid, total monomeric anthocyanin, total antioxidant capacity (DPPH, ABTS and FRAP assays) and phenolic compounds of aronia fruit extracts were analyzed. There were significant differences in the measured parameters depending on the extraction method and solvent type. Extracts in ultrasound extraction and classical …


Characterization And Bioremediation Potential Of Heavy-Metal Resistant Bacteria Isolated From Agricultural Soil, Kheira Dahnoun, Fatima Djadouni, Badiaa Essghaier, Chahnez Naccache, Nadia Zitouna, Salwa Zehdi-Azouzi, İsmai̇l Bayyi̇ği̇t, Hijran Rafiyeva Latif, Maha Mezghani-Khemakhem, Hedia Bourguiba Aug 2024

Characterization And Bioremediation Potential Of Heavy-Metal Resistant Bacteria Isolated From Agricultural Soil, Kheira Dahnoun, Fatima Djadouni, Badiaa Essghaier, Chahnez Naccache, Nadia Zitouna, Salwa Zehdi-Azouzi, İsmai̇l Bayyi̇ği̇t, Hijran Rafiyeva Latif, Maha Mezghani-Khemakhem, Hedia Bourguiba

Turkish Journal of Agriculture and Forestry

Heavy metal pollution is a major environmental issue that has a negative impact on soil quality and food security. As a result, heavy metal removal or remediation from hazardous sites has become mandatory. Bioremediation based on microorganisms is a promising method to remediate heavy metal-contaminated areas due to its eco-friendly, cost-effective, and highly efficient characteristics. This study aimed to isolate, identify and characterize rhizospheric bacteria able to resist, reduce, and detoxify heavy metals (chromium [Cr], nickel [Ni], and aluminum [Al]) from agricultural soil. Two isolates were chosen due to their high level of heavy metal resistance and could serve as …


Developing Micropropagation Protocol For Black Mulberry (Morus Nigra L.), Merve Özkul, Nevzat Sevgi̇n, Mehmet Özkul, Neelam Prabha Negi, Sadi̇ye Peral Eyduran, Bi̇rsen Yilmaz, Melekşen Akin Aug 2024

Developing Micropropagation Protocol For Black Mulberry (Morus Nigra L.), Merve Özkul, Nevzat Sevgi̇n, Mehmet Özkul, Neelam Prabha Negi, Sadi̇ye Peral Eyduran, Bi̇rsen Yilmaz, Melekşen Akin

Turkish Journal of Agriculture and Forestry

This study aims to develop a suitable micropropagation protocol for black mulberry, which cannot be easily clonally propagated like other mulberry species. Clonal propagation of this species is gaining importance due to its health benefits and utilization in pharmacology. The effects of culture media and cytokinin types on micropropagation of Morus nigra L. were investigated. Single-axillary bud explants grown on MS, DKW, and NRM containing 0.25 mg/l benzyl adenine (BA) plus 0.01 mg/l indole-3-butyric acid (IBA) were compared to cultures grown on NRM with thidiazuron, metaTopolin (mT) or BA at 1.25, 2.5, 5.0 or 7.5 mg/l plus 0.01 mg/l IBA. …


Evaluation Of Turkish Shallot Genetic Resources For Morphological, Biochemical And Sensory Properties, Gülay Beşi̇rli̇ Aug 2024

Evaluation Of Turkish Shallot Genetic Resources For Morphological, Biochemical And Sensory Properties, Gülay Beşi̇rli̇

Turkish Journal of Agriculture and Forestry

Shallots, a subspecies of onion, are considered the gourmet onion and are preferred especially in French and Asian cooking. Its unique taste and aroma especially being caramelized through heat treatment increases its importance for boutique restaurants and niche tables. This study examined the morphological, biochemical, and sensory properties of seven generatively (GMSY-2, GMSY-3, GMSY-4, GMSY-5, GMSY-6, GMSY-7, GMSY-8) and one vegetatively propagated (GMSY-1) shallot genotypes in 2021 and 2022. Sixteen morphological and fifteen biometric features of UPOV were used in characterization. Total phenolic content, total antioxidant capacity, and total monomeric anthocyanin and pyruvic acid contents were determined as biochemical markers. …


Identification And Extraction Method Of Fragrant Pear Based On Image Detection Under Internet Of Things Applications, Peng Zhou, Huan Wnag, Pengwei Zhang, Shengzhi Liu, Wei Cehn, Weihang Zhao, Bingyu Cao Aug 2024

Identification And Extraction Method Of Fragrant Pear Based On Image Detection Under Internet Of Things Applications, Peng Zhou, Huan Wnag, Pengwei Zhang, Shengzhi Liu, Wei Cehn, Weihang Zhao, Bingyu Cao

Turkish Journal of Agriculture and Forestry

With the continuous development of society, agricultural production technology is also improving. Due to the continuous improvement of economic level, the quality of life has also put forward higher requirements, the quality of agricultural products has gradually received more people’s attention. In the picking and sorting process of traditional fragrant pear, the quality control process is not perfect, and the identification and extraction method is not mature enough. In the complex environment of insufficient light or shade of branches and leaves, the pear picking work cannot quickly and accurately locate the target fruit. Therefore, the traditional identification and extraction methods …


Cover And Content Aug 2024

Cover And Content

Turkish Journal of Physics

No abstract provided.


A New Approach: Ordinal Predictive Maintenance With Ensemble Binary Decomposition (Opmeb), Ozlem Ece Yurek, Derya Birant Jul 2024

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 …


Enrichment Of Turkish Question Answering Systems Using Knowledge Graphs, Okan Çi̇ftçi̇, Fati̇h Soygazi̇, Selma Teki̇r Jul 2024

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 …


Ensemble Learning For Accurate Prediction Of Heart Sounds Using Gammatonegram Images, Sinam Ashinikumar Singh, Sinam Ajitkumar Singh, Aheibam Dinamani Singh Jul 2024

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 …


Detection And Classification Of Unauthorized Use Of Irrigation Motors In Agricultural Irrigation, Önder Ci̇velek, Sedat Görmüş, Hali̇l İbrahi̇m Okumuş, Orhan Gazi̇ Kederoglu Jul 2024

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 Jul 2024

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. …


A Real-Time Embedded System Designed For Nilm Studies With A Novel Competitive Decision Process Algorithm, Sai̇d Mahmut Çinar, Rasi̇m Doğan, Emre Akarslan Jul 2024

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 …


Multi-Label Voice Disorder Classification Using Raw Waveforms, Gökay Di̇şken Jul 2024

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 …


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 Jul 2024

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, …


Efficient Deep Neural Network Compression For Environmental Sound Classification On Microcontroller Units, Shan Chen, Na Meng, Haoyuan Li, Weiwei Fang Jul 2024

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 …


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 Jul 2024

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 Jul 2024

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 Jul 2024

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 Jul 2024

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 Jul 2024

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 …


Positive And Decreasing Solutions For Higher Order Caputo Boundary Valueproblems With Sign-Changing Green’S Function, Rian Yan, Yige Zhao, Xuan Leng, Yabing Li Jul 2024

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.


Stacks In Einstein Gravity, Kadri̇ İlker Berktav Jul 2024

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.


Curves As Slant Submanifolds Of An Almost Product Riemannian Manifold, Pablo Alegre, Alfonso Carriazo Jul 2024

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.


Properties Of Gyrogroups Induced By Groups Whose Central Quotients Being 2-Engel, Jaturon Wattanapan, Teerapong Suksumran Jul 2024

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.


The Flow-Geodesic Curvature And The Flow-Evolute Of Spherical Curves, Mircea Crasmareanu Jul 2024

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.


Interior Schauder-Type Estimates For M − Th Order Elliptic Operators Inrearrangement-Invariant Sobolev Spaces, Emi̇nağa M. Mamedov, Şeyma Çeti̇n Jul 2024

Interior Schauder-Type Estimates For M − Th Order Elliptic Operators Inrearrangement-Invariant Sobolev Spaces, Emi̇nağa M. Mamedov, Şeyma Çeti̇n

Turkish Journal of Mathematics

In this study, we investigate the m-th order elliptic operators on n-dimensional bounded domain Ω ⊂ Rnwith discontinuous coefficients in the rearrangement-invariant Sobolev space WmX (Ω). In general, the consideredrearrangement-invariant spaces are not separable, so the use of classical methods in these spaces requires substantialmodification of classical methods and a lot of preparation, concerning correctness of substitution operator, problemsrelated to the extension operator in such spaces, etc. For this purpose, the corresponding separable subspaces of thesespaces, in which the set of compact supported infinitely differentiable functions is dense, are introduced based on theshift operator. We establish interior Schauder-type estimates in …


On Vietoris’ Hybrid Number Sequence, Nurten Gürses, Gülsüm Yeli̇z Saçli, Sali̇m Yüce Jul 2024

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.