Ejons International Journal on Mathematic, Engineering and Natural Sciences

Multicolor Photometric Analysis of the Eclipsing Binary Star V1817 Aql

2025-07-14T13:38:38+03:00

In this study, the analysis of the BVR multi-color photometric observation data of the V1817 Aql is presented. The photometric observation of the system were obtained during the 2024 observing season at the Çanakkale Onsekiz Mart University Astrophysics Research Center and Ulupınar Observatory using a MEADE LX200 model 30 cm Cassegrain-Schmidt telescope equipped with an SBIG STL-1001E CCD camera and BVR filters. The BVR light curves of the system were analyzed using the Wilson-Devinney code. The photometric mass ratio of V1817 Aql was determined to be 0.323±0.006. Accordingly, the mass and radius values of the components of the V1817 Aql binary system were derived to be M₁=1.58±0.16 M_ʘ, R₁=1.47±0.12 R_ʘve M₂=0.46±0.10 M_ʘ, R₂=1.27±0.26 R_ʘ and the evolutionary status of the components has been discussed.

Evaluation of Public Spaces in the Context of Architectural Psychology: Beşiktaş - Ortaköy Axis

2025-07-22T15:37:30+03:00

Space and individual are in a process cycle that affects each other. While spatial comfort conditions are physical and measurable conditions such as thermal, lighting, sound, smell, which are related to the function of the space; psychological comfort conditions, which can be described with words such as privacy, belonging, peace, happiness, security, status and socialisation, should be solved at an optimal level for a physical environment. In this context, since public spaces are places that allow an individual to perform an action, it is expected to provide physical and psychological comfort conditions. This study aims to evaluate the effects of physical building elements in public spaces on individuals. The main goal of the case analysis in the study is to determine which emotions the architectural elements that make up the physical environment reveal in the users. The study covers Çırağan Street, which connects Beşiktaş and Ortaköy neighbourhoods on the European side of Istanbul. The act of walking on the axis on the street and the psychological feelings created by the buildings and architectural elements on the axis were evaluated. As a result of the study, it was determined that the physical environment creates some emotional states on the individual.

Effect of Iron Content and Sintering Temperature on Microstructure and Hardness of Al-Fe Alloys

2025-07-23T13:13:49+03:00

In this study, the effects of iron content and sintering temperature on the microstructure and hardness of Al-Fe-based alloys were investigated. Samples were produced via the powder metallurgy method and sintered at 610 °C and 640 °C. Scanning electron microscopy (SEM) and Brinell hardness tests were conducted for characterization. Microstructural analyses revealed that some iron particles remained unreacted at 610 °C, while at 640 °C, the formation and homogenization of Al₃Fe intermetallic phases were more evident. The hardness results showed that both increasing Fe content and higher sintering temperature contributed to improved Brinell hardness. These findings suggest that optimizing the sintering temperature and alloy composition can significantly enhance the mechanical performance of Al-Fe alloys.

Evaluation of Paleoenvironmental Conditions Using Petrographic Data in Şarkikaraağaç (Isparta) Coals

2025-07-28T15:51:18+03:00

In this study, the maceral composition and depositional environment of the Şarkikaraağaç coal seam were examined in detail. The results show that huminite is the most abundant maceral group in the coal samples, ranging from 25% to 75%. This is followed by liptinite (1–36%) and inertinite (4–15%). Notably high mineral matter content and abundant framboidal pyrite are among the features that stand out. The relatively low and uniform huminite reflectance values across the basin indicate a consistent and homogeneous coalification process. Based on the maceral distribution and ternary diagram evaluations, it is inferred that the coals predominantly formed in shallow, alkaline, and anoxic wetland environments, specifically of limnic to limnotelmatic character. According to the petrographic composition of the Şarkikaraağaç coals, the coal seams were formed mostly under stagnant water conditions, with the dominant plant input being herbaceous and limited contributions from woody plants.

Effect of Smoke Solution Doses on the Germination Performance of Radish Seeds Under Salt Stress

2025-08-06T12:42:35+03:00

This study aimed to evaluate the effects of different smoke solution doses (0%, 0.1%, 0.5%, and 1%) derived from hazelnut husk on the germination performance and oxidative stress response of two radish (Raphanus sativus L.) cultivars under salinity stress (150 mM NaCl). Morphological parameters (root and shoot length, fresh weight, germination percentage, and vigor index) and malondialdehyde (MDA) levels were assessed. The results showed that salt stress markedly increased MDA content, indicating enhanced oxidative damage in both cultivars. However, low smoke solution doses, particularly in the 2nd trial 0.1%, alleviated oxidative stress and improved germination traits in Ateş, while the 0.5% dose promoted root growth and vigor in Akkaya. The findings indicated that salinity stress increased MDA content, reflecting oxidative damage, and negatively affected germination in radish, with cultivar-specific responses. Moreover, smoke solution treatments exhibited dose- and cultivar-dependent effects, some of which may enhance germination performance, while others may induce inhibitory responses in certain physiological parameters.