Asian Journal of Physical and Chemical Sciences

An Introduction and Reexamination of Molecular Hypergraph and Molecular n-SuperHypergraph

2025-05-20T09:57:54+00:00

A molecular graph is a labeled graph in which atoms are represented by vertices and covalent bonds by edges, with each edge labeled according to the bond type (Gasteiger et al., 2020). A hypergraph generalizes the concept of a traditional graph by allowing edges—called hyperedges—to connect more than two vertices simultaneously (Berge, 1984). A superhypergraph further extends this idea by incorporating recursively defined powerset layers, enabling hierarchical and self-referential relationships among hyperedges (Smarandache, 2020).

This paper investigates the formalization, illustrative examples, and structural properties of molecular hypergraphs and molecular superhypergraphs (cf. (Fujita, 2025c)). These constructs, grounded in the theoretical foundations of hypergraphs and superhypergraphs, provide enriched frameworks for representing molecular systems and facilitate deeper exploration of hierarchical chemical connectivity and molecular structure.

Spectrophotometric Investigation of the Solubilization and Thermodynamics of Eriochrome Blue Black R in Cationic, Nonionic and Zwitterionic Surfactant Systems

2025-05-20T10:35:09+00:00

.This study investigates the interactions between the anionic dye Eriochrome Blue Black R and three types of surfactants (cationic CTAB, nonionic TX-100, and zwitterionic CAPB) using UV-visible spectrophotometry. The solubilization efficiency and thermodynamics of dye-surfactant interactions was evaluated by determining binding constants and partition coefficients K_Xfor each surfactant systems, and it was found that CTAB exhibits the highest solubilization efficiency due to strong electrostatic attraction. The thermodynamic analysis confirms that these dye-surfactant interactions are spontaneous, with electrostatic and hydrophobic forces playing a key role. The nonionic TX-100 and zwitterionic CAPB demonstrated comparatively lower dye-binding capabilities. These findings provide valuable insights into dye-surfactant systems, which are relevant to applications in wastewater treatment, dye removal, and formulation chemistry.

SCAPS-1D Numerical Simulation of Homojunction and Heterojunction ZnO/Si Solar Cells

2025-05-31T10:58:55+00:00

In this article, numerical simulations of the electrical current-voltage characteristics of an n-Si / p-Si homojunction solar cell and an n-ZnO / p-Si heterojunction solar cell are performed. In order to find the optimal structure of the solar cells, numerical modelling using SCAPS-1D (Solar Cell Capacitance Simulator One Dimension) is performed. We study the effect of both emitter and base thicknesses and doping on the cell output parameters which are open circuit voltage (Voc), short circuit current density (Jcc), form factor (FF) and conversion efficiency (n). A comparison between the homojunction and heterojunction structures is also made in order to find which one of the two structures has the better conversion efficiency. For the same optimal values of the input parameters, we found that the conversion efficiency of the n-ZnO / p-Si heterojunction (23.23%) is higher than that of the n-Si / p-Si homojunction (20.08%). Therefore, the presence of a transparent conductive oxide (TCO) such as an n-ZnO layer on p-type silicon can improve the conversion efficiency of the solar cell due to the anti- reflection effect of the TCO layer.

Effects of Grewia Bicolor Fiber on the Thermomechanical Properties of Earthen Bricks for Sustainable Habitat Construction

2025-06-02T07:03:13+00:00

The context of sustainable development, which forces humans to protect the planet, imposes in its objectives to move towards the use of locally accessible materials in the field of construction. The objective of the present research work is to study the effect of Grewia bicolor fiber content on the properties of adobes. Specifically, this involves measuring the compressive and flexural strengths, thermal resistance, conductivity and effusivity of adobes. In this regard, we carried out geotechnical, physical, chemical, mineralogical characterization of soils taken from Mayo Kebbi Est region especially from Fianga Lengoua 1, Fianga Lengoua 2, Bongor, Moulkou, and Guelendeng and from Loumia in Chari Baguirmi region. Various methods and means of identification of soils have been used, including geotechnical, chemical and mineralogical analyzes. According to the geotechnical characterization of soils, Fianga Lengoua 1 soil is a sandy-silt-loam with plasticity index of 18%, Fianga Lengoua 2 soil is a clay-sandy with a plasticity index of 26%, Bongor soil is clayey with plasticity index of 23%, Moulkou soil is clay-sandy-loamy with plasticity index of 17% and Guelendeng soil is clay-sandy-loamy with plasticity index of 20%; in Chari Baguirmi, Loumia soil is clay-sand with plasticity index of 17%. These results indicate that the six samples are soils of type A2 except Fianga Lengoua 2 soils of type A3. Physicochemical analysis results show a pH value greater than 6 for the six samples. They are aluminosilicates. Oraganic materials presents in the samples are less than 2%. The results of these characterization indicate that Fianga Lengoua 1 soil is suitable for the formulation of raw earth block which has 36% clay and it is in ideal zone of the soils according to texture triangle but the five others soils are appropriate for hydraulic lam.

The Impact of Physics Education on High School Students Problem-solving Skills: A Case Study from Sheberghan City, Afghanistan

2025-06-19T06:39:39+00:00

This study employs a mixed-methods research design involving 200 randomly selected secondary school students in Sheberghan to explore the impact of physics education on the development of problem-solving skills. Problem-solving is a fundamental competency in both academic and real-world contexts, and this research aims to evaluate how targeted physics instruction can enhance this essential skill set. The quantitative phase involved administering pre- and post-instruction surveys and standardized assessments to measure changes in students' problem-solving abilities. The qualitative phase, which complemented the quantitative data, included in-depth interviews and classroom observations to gain deeper insights into students’ and teachers’ perspectives. The findings revealed that instructional strategies—particularly hands-on experiments and collaborative learning activities—led to significant improvements in students' problem-solving performance. For instance, the average test scores increased from 66 to 75 following the intervention. Despite these overall gains, some students continued to struggle with complex problem-solving tasks, highlighting the need for differentiated instructional support. In conclusion, the study emphasizes the importance of innovative and interactive teaching approaches in physics education and recommends their systematic integration into school curricula to enhance student learning outcomes.

The Effect of Geometric Adjustments in an Indirect Forced Convection Solar Tunnel Dryer: A Study Based on CFD Simulations and Experimental Investigations

2025-06-24T08:25:25+00:00

The quality of dried agri-food products depends on the uniformity of their moisture content at the end of the drying process. Controlling parameters such as temperature, air velocity, and relative humidity within the dryer is essential to ensure optimal drying. This study presents the design of a tunnel-type indirect solar dryer intended for drying agri-food products. The main scientific challenge lies in the numerical evaluation and proposal of solutions to improve the dryer's performance. With this in mind, a numerical simulation was carried out using computational fluid dynamics (CFD) to analyse the distribution of air flow and temperatures inside the dryer. Three simulation models were developed, with variable input values: air speed (1 m/s, 2 m/s and 3 m/s) and the temperature of the wall exposed to solar radiation (40°C, 50°C and 60°C). To validate the numerical results, an experimental study was conducted. Comparisons revealed high coefficients of determination between the simulated and experimental data: R² = 0.9951 for temperature and R² = 0.9217 for air velocity. Geometric adjustments were then made to the CFD model. The right angles (90°) at the upper ends of the drying chamber were changed to flat angles (0°), while those at the lower ends were replaced by 45° angles. These modifications led to an optimisation of the dryer's thermal performance, as well as a significant improvement in the efficiency of the drying process.