-
Research Article
Studying the Effect of Yttrium Concentration on the Structural and Superconducting Properties of YBCO Superconductors
Mozdlifa Bayin Mohamed*,
Mahmoud Hamid Mahmoud Hilo
,
Ahmed Abubaker Mohamed
Issue:
Volume 14, Issue 5, October 2025
Pages:
185-191
Received:
20 July 2025
Accepted:
5 August 2025
Published:
13 September 2025
Abstract: High-temperature superconductors (HTS) are widely utilized in modern technological applications due to their unique properties, primarily the expulsion of magnetic fields and nearly zero electrical resistance. This study investigates the influence of varying yttrium (Y) concentrations on the structural and superconducting properties of Yttrium Barium Copper Oxide (YBCO) superconductors. Three samples with different Y concentrations (Y = 1.00, 0.90, and 0.80) were synthesized using a solid-state reaction method. The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results revealed a phase transition from orthorhombic (space group Pmmm) at higher Y concentrations (Y = 1.00 and 0.90) to tetragonal (space group P4/mmm) at Y = 0.80, indicating a deterioration of superconducting properties. SEM analysis showed significant microstructural changes with Y concentration variations. The Y = 0.90 composition demonstrated an optimal balance of grain connectivity and porosity, suggesting it is suitable for high-performance superconducting applications. These findings highlight the critical role of yttrium concentration in tailoring YBCO properties for specific technological uses.
Abstract: High-temperature superconductors (HTS) are widely utilized in modern technological applications due to their unique properties, primarily the expulsion of magnetic fields and nearly zero electrical resistance. This study investigates the influence of varying yttrium (Y) concentrations on the structural and superconducting properties of Yttrium Bari...
Show More
-
Research Article
Enhanced Functional Properties of Sol-gel Derived ZnO-based Nanocomposite Thin Films Incorporating Ag, TiO2, and Graphene Nanoparticles
Issue:
Volume 14, Issue 5, October 2025
Pages:
192-199
Received:
12 August 2025
Accepted:
21 August 2025
Published:
13 September 2025
Abstract: This study reports the synthesis and characterization of ZnO-based nanocomposite thin films prepared by the sol-gel method associated with spin coating technique, with incorporation of silver (Ag), titanuim oxide (TiO2), and graphene nanoparticles as functional additive. The aim of this work is to investigate the influence of these nanoinclusions on the structural, optical, and electrical properties of ZnO thin films. X-ray diffraction (XRD) results confirm the retention of the hexagonal wurtzite structure of ZnO, with additional reflections at 38,1°, 44,3°, and 64,4° attributed to Ag, 25,3° and 48 ° to anatase TiO2, and a broad peak near 26° to GO. Scanning Electron Microscopy (SEM) analyse reveals enhanced grain connectivity and surface uniformity in composite films. UV-Vis spectroscopy indicates a tunable optical bandgap and improved transmittance in the visible range, especially for TiO2 and graphene-loaded films. Electrical measurements show a significant decrease in resistivity from 4,5*103 Ω.cm (ZnO) to 3,2*102 Ω.cm (ZnO-Ag), 1,7*102 Ω.cm in the ternary composite, with corresponding conductivity up to 5,9*10-3 S/cm and carrier mobility of 7,6 cm2/V.s in Ag and graphene-containing films, attributed to improved charge carrier mobility and percolation pathways. The multifunctional enhancement observed in these ZnO nanocomposites positions them as promising materials for transparent electrodes, photocatalytic devices, and UV photodetectors.
Abstract: This study reports the synthesis and characterization of ZnO-based nanocomposite thin films prepared by the sol-gel method associated with spin coating technique, with incorporation of silver (Ag), titanuim oxide (TiO2), and graphene nanoparticles as functional additive. The aim of this work is to investigate the influence of these nanoinclusions o...
Show More
-
Review Article
Influence of Natural Fiber Properties on the Mechanical Performance of Unfired Earthen Blocks
Issue:
Volume 14, Issue 5, October 2025
Pages:
200-211
Received:
18 August 2025
Accepted:
1 September 2025
Published:
19 September 2025
Abstract: Rapid population growth and accelerated urbanization are intensifying pressure on natural resources and the construction sector, which remains heavily dependent on conventional, high-carbon materials such as concrete and steel. In this context, compressed earth blocks are attracting renewed interest due to their environmental and socio-economic advantages. However, their low mechanical strength and limited durability require targeted performance improvements. This review explores natural fiber reinforcement as a sustainable strategy for enhancing the properties of unfired earth blocks. Drawing on over 60 peer-reviewed studies, it examines how fiber characteristics, dimensions, tensile strength, Young’s modulus, and biochemical composition, affect the compressive, tensile, and flexural strength of these materials. Findings show that reinforcement efficiency is determined not only by the intrinsic physical and mechanical properties of the fibers but also by fiber–matrix interfacial bonding and the experimental protocols employed. Importantly, fibers with high tensile strength do not necessarily yield improved performance when adhesion between matrix and fibers is poor. The review emphasizes the need for standardized testing procedures, detailed fiber characterization, and optimized surface treatments to improve compatibility with earthen matrices, thereby advancing the development of durable, low-carbon construction materials.
Abstract: Rapid population growth and accelerated urbanization are intensifying pressure on natural resources and the construction sector, which remains heavily dependent on conventional, high-carbon materials such as concrete and steel. In this context, compressed earth blocks are attracting renewed interest due to their environmental and socio-economic adv...
Show More
-
Research Article
Synthesis and Characterization of Iron Nanoparticles from Acid Mine Drainage Using Sodium Borohydride as Reductant
Issue:
Volume 14, Issue 5, October 2025
Pages:
212-223
Received:
15 July 2025
Accepted:
4 August 2025
Published:
23 September 2025
Abstract: The large volume of toxic acid mine drainage wastewater generated from the pyritic oxidation of coal and gold mine result in serious environmental pollution because of the problem of waste disposal. The aim of this study is to use iron-rich raw acid mine drainage (RAMD) as a substitute to commercial reagent grade iron salt to synthesize iron nanoparticles. Chemical reduction method was employed to synthesize iron nanoparticles using sodium borohydride as reductant. The synthesized iron nanoparticles from RAMD and reagent grade iron salt solutions were quantified and characterized using analytical techniques such as ion chromatography (IC), Inductively coupled plasma-optical-emission spectroscopy (ICP-OES), X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), High resolution transmission electron microscopy-Selected area electron diffraction (HRTEM-SAED), X-ray fluorescence (XRF), Brunauer-Emmett-Teller (BET), Fourier Transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and Thermogravimetric analysis (TGA). The ICP-OES result revealed high iron concentration (4784.13 mg/L) and IC sulphate concentration (27, 204. 72 mg/L that iron sulphate salt was present in the RAMD solution. XRD results identified magnetic pure iron mineral phase for both samples and the SEM results revealed spherical crystal particle morphology as long interwoven strand with beads. The HRTEM results revealed a bead-like necklace structure with average particle size of 28.48 ± 4.2 nm and 24.23 ± 2.17 nm for iron nanoparticles synthesized from RAMD (A) and ferric chloride (B) respectively. The XRF elemental composition of the synthesized nanoparticles revealed A (97.4%) and B (99.9%) iron (Fe). BET surface area results for A is 89 ± 3.13 m2/g and B is 93 ± 3.16 m2/g, FTIR results revealed O-H, CO2, Fe and FeO absorption peaks and the AFM results revealed more agglomeration in sample A than in B. The TGA of both synthesized iron nanoparticles were thermally stable. In conclusion, the iron-rich RAMD wastewater was found to be a good substitute for reagent grade iron salt use for making quality iron nanoparticles.
Abstract: The large volume of toxic acid mine drainage wastewater generated from the pyritic oxidation of coal and gold mine result in serious environmental pollution because of the problem of waste disposal. The aim of this study is to use iron-rich raw acid mine drainage (RAMD) as a substitute to commercial reagent grade iron salt to synthesize iron nanopa...
Show More
