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- MakaleAçık Erişim2026Energy density in Rainbow Gravity: Levi-Civita Model
Korunur, Murat; Korunur, Sibel
In this study, the energy density for the Levi-Civita space-time is analyzed within the framework of Rainbow Gravity Theory (RGT). RGT is a theoretical approach that assumes the geometry of space-time depends on the energy of the test particle, offering a promising perspective in the quest for quantum gravity. Energy densities are calculated using the Einstein, Bergmann-Thomson, and Landau-Lifshitz energy-momentum prescriptions and compared with the results obtained from General Relativity. The findings reveal that as the test particle’s energy increases, the energy density rises in the Einstein and Landau-Lifshitz prescriptions, while it decreases in the Bergmann-Thomson formulation. This highlights how the problem of energy localization varies across different energy-momentum definitions and demonstrates the impact of RGT on energy distribution. The study contributes to the literature exploring the influence of alternative gravitational theories on energy-momentum distributions.
- MakaleAçık Erişim2024Examining Pre-Service Science Teachers' Personal and Enacted Pedagogical Content Knowledge About Seasons
Kılıç, Aygün
This study examined pre-service science teachers’ pedagogical content knowledge (PCK) about seasons. The framework of this study was based on the Refined Consensus Model (RCM), and pre-service teachers’ topic-specific PCK was also discussed in two dimensions: personal PCK (pPCK) and enacted PCK (ePCK), which are included in this model. The pPCK of the pre-service teachers represents their declarative PCK, and their ePCK represents their dynamic PCK. This qualitative descriptive research included 18 pre-service science teachers. In the study, knowledge of pre-service teachers’ pPCK was collected in vignette-based individual semi-structured interviews, and data on their competencies regarding their ePCK, which they revealed in a real classroom environment, were collected through field observations and teaching video recordings. The study’s qualitative data were evaluated using two separate rubrics developed by the author using the literature. Accordingly, it was determined that the pre-service teachers who participated in the research had limited pPCK and ePCK on the seasons and that their topic-specific pPCK was partially better quality than their topic-specific ePCK. Moreover, pre-service teachers’ ePCK was observed to be different from their pPCK, but their ePCK was based on their pPCK. In this context, it was seen that the results of this research are consistent with RCM.
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İncele - MakaleAçık Erişim2024Teleparallel Energy Density within the Framework of Rainbow Gravitation Theory for A Spatial Self-Similar, Local Rotational Symmetric Model
Korunur, Murat; Korunur, Sibel
It is known that the general theory of relativity provides valuable answers about our universe. General relativity theory is used to describe space, time, and mass-energy interactions, while quantum theory is used to explain the behavior and interactions of microscopic particles. The gap between these two theories reveals the need to develop a unified theory of "quantum gravity". However, so far no universal theory has yet been found that fully resolves this conflict. This is a big puzzle that physicists have been working on for a long time, and unifying these two theories harmoniously is one of the biggest challenges in modern physics. One of the theories put forward for this purpose is the "Rainbow" theory of gravity. In this study, Einstein, Bergmann-Thomson and Landau-Lifshitz energy densities are calculated for a spatial self-similar, locally rotationally symmetric model using teleparallel geometry within the framework of the Rainbow theory of gravity. However, the results obtained are evaluated using rainbow functions that are well known in the literature. The obtained results are rewritten as explicit forms of energy densities for Einstein, Bergman-Thomson and Landau-Liftshitz representations using f_1 (\\chi)=1/(1-\\chi)and f_2 (\\chi)=1 rainbow functions. Accordingly, it has been shown that the test particle changes its energy density for the Einstein and Bergmann-Thomson energy-momentum prescriptions but does not change the energy density for the Landau-Liftshitz energy-momentum prescription.
- MakaleAçık Erişim2023Novel Quaternary CuAlZnMg High Temperature Shape Memory Alloy (HTSMA) Fabricated by Minor Batch of Zn and Mg Additions
Özkul, İskender; Boyrazli, Mustafa; Aksu Canbay, Canan; Başbağ, Güneş; Karaduman, Oktay
Shape memory alloys (SMAs) constitute the second largest commercial smart material class after piezoelectric materials. Different SMA alloy systems or SMAs with miscellaneous functionalities and characteristic properties have been designed for using in different applications until today. High temperature shape memory alloys (HTSMAs) are also widely desired to be used in various smart materials applications. HTSMAs with different functional and characteristic properties are muchly demanded for different tasks to be done by these alloys or devices designed by these alloys. A common and practical way to fabricate SMAs or HTSMAs with different shape memory effect (SME) and other properties is to fabricate them with different alloying compositions and add different additive elements. In this work, a quaternary CuAlZnMg HTSMA with an unprecedented composition consisting minor amount of zinc and magnesium additives was produced by arc melting method. As a result of applying post-homogenization in high β–phase temperature region and immediate quenching, the microstructural mechanism of a SME property was formed in the produced alloy. After then, to examine SME characteristics of the CuAlZnMg alloy some differential thermal analysis (DTA), microstructural (XRD) and magnetization (VSM) characterization tests were carried out. The DTA results showed that the alloy is a HTSMA exhibiting reverse martensitic transformations at temperature range between 167 °C and 489 °C. The XRD pattern obtained at room temperature revealed the martensite phases formed in the alloy, which phases are the base mechanism of the reversible martensitic transformation (the SME property) of the alloy. The VSM test showed that the alloy exhibit a diamagnetic property with a weak ferromagnetic coercivity contribution.
- MakaleAçık Erişim2020Kontakt Metrik Çiftler Üzerinde Genelleştirilmiş Quasi-Conformal Eğrilik Tensörü
Ünal, İnan
Bu çalışmanın amacı, normal metrik kontakt çift (NMCP) manifoldlarını genelleştirilmiş quasi-conformal eğrilik(GQC) tensörünün sıfırlık koşulları altında incelemektir. Bu kapsamda GQC-düz ve GQC-Z-düz NMCP manifoldları ileilgilenilmiştir. Bir GQC-düz manifoldun genelleştirilmiş yarı-Einstein (GQE) manifold olduğu ve bu çeşit manifoldlarıngenelleştirilmiş yarı-sabit eğriliğe sahip olduğu ispatlanmıştır. Son olarak, GQC eğrilik tensörünün düzlük şartları altında,NMCP manifoldlarının kesitsel eğrilikleri ele alınmıştır.
AtıfTR Dizin1İncele - MakaleYalnız künye2017Absolute Parallelism in The Bainchi-Type IX Taub Solution
Korunur, Murat
Bu çalışmada, mutlak paralellizm olarak bilinen alternatif bir bakış açısıyla ünlü kütleçekim problemlerinden birini inceliyoruz. Bainchi-Type IX uzay-zamanın Taub çözümü ve mutlak paralellizmde Hamilton yaklaşımı tekniği göz önüne alındığında, bu duruma karşılık gelen açısal momentum, toplam enerji ve momentum dağılımları elde edilmektedir. Temel sonuçlarımızın diğer bir yazar tarafından literatürde yayınlanan sonuçlarla uyumlu olduğu görülmektedir
- MakaleYalnız künye2016New complex exact travelling wave solutions for the generalized- Zakharov equation with complex structures
Bulut, Hasan; Baskonus, Haci Mehmet
In this paper, we apply the sine-Gordon expansion method which is one of the powerful methods to the generalized-Zakharov equation with complex structure. This algorithm yields new complex hyperbolic function solutions to the generalized-Zakharov equation with complex structure. Wolfram Mathematica 9 has been used throughout the paper for plotting two- and three-dimensional surface of travelling wave solutions obtained.