Search

Aluminium metal matrix composites (AMMCs) using alumina (Al2O3) and silicon carbide (SiC) as reinforcement elements are gaining significant interest in various applications because of their excellent properties. In this study, Al2O3/SiC with compositions (0.5 wt.%, 1.5 wt.%, and 2.5 wt.% for each) were used as reinforcement elements in an aluminium alloy (AA2024-T6). The samples prepared were AA2024-T6 + (0.5Al2O3/0.5SiC), AA2024-T6 + (1.5Al2O3/1.5SiC), and AA2024-T6 + (2.5Al2O3/2.5SiC) using a stir-casting technique. The experimental study included density calculation mechanical properties, such as tensile strength, compressive strength and hardness. The study also included a microstructure examination of the fracture surface of the tensile specimens. The results showed that incorporating Al2O3/SiC as reinforcement materials into aluminium AA2024-T6 significantly improved its properties. Hence, increasing the reinforcement with compositions of 2.5Al2O3/2.5SiC into AA2024-T6 showed a drop in density and increased mechanical properties, such as ultimate tensile strength, compressive strength and hardness, compared to the base alloy (AA2024-T6). Furthermore, the scanning electron microscopy analysis revealed the uniform distribution of the reinforcement particles resulting in strong bonding with the matrix. The findings suggest that Al2O3/SiC reinforced with AA2024-T6 can be used in applications where a combination of lightweight and high strength is needed.

Solubility enhancement of poorly aqueous-soluble drugs, like Terbinafine (TBN), is a critical challenge in formulating effective dosage forms. This study focused on developing β-cyclodextrin (β-CD) and polyacrylamide (PAM)-based microgels to address the solubility issue of TBN, classified as a biopharmaceutics classification system class II drug. The microgels were crafted through free radical polymerization, employing methylene bisacylamide as a cross-linker and methacrylic acid as a monomer, initiated by ammonium persulfate. Comprehensive characterizations, including Fourier transform infrared, thermo-gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, powder X-ray diffractometry analysis, Zeta size, and Zeta potential, were conducted. In vitro studies, such as drug release and swelling, were performed at pH 1.2. Toxicity analysis in rabbits revealed zero toxicity. These β-CD/PAM microgels successfully enhanced the solubility of TBN.

Glycine max L. (soybean) is an important leguminous staple crop. In this study, nutritional value, bioactive compounds, and antioxidant properties of soybean milled fractions (MF) were determined. Protein contents in different milled fractions ranged from 4.6% to 47.2%, and fat contents ranged from 1.9% to 22.1%. MF amino acid contents ranged from 6.8% to 37.9 g/100 g. Glycitein and genistin were the most concentrated isoflavones in the cotyledon and germ fractions. Although MF phenolics of protocatechuic, chlorogenic, hydroxybenzoic, vanillic, caffeic, and sinapic acids were abundant in bound and free phenolic extracts. In addition, MF total phenolic indexes ranged from 65 to 270.1 GAE/100 g and total flavonoid 7.5 to 92.3 mg GAE/100 g, which were found to be the most active of FRAP (80.2–197.1) and ABTS (28.2–125.6 µmol TEAC/100 g), respectively. The overall results provided useful information and encouraged the effective utilization of soybean-milled fractions as functional food ingredients for health requirements.

In recent years, Piezoelectric Transformers (PTs) have become a great success due to their excellent properties, especially in applications requiring high voltage. The Rosen-type PT is well known for this performance, as its voltage gain at the resonant frequency can reach few thousands. However, the high output impedance of this device can make an accurate electrical measurement of the output voltage difficult, hence the need to ensure good impedance matching along the measuring electrical test setup. For this purpose, two high impedance oscilloscope probes were successively added to the secondary side to further emulate the measurement chain and match the experiments as closely as possible with the developed 1D model. Accordingly, for an unloaded Rosen type piezoelectric transformer, made of hard ceramic (pz26) with corresponding dimensions 2L×w×t =25 mm×3 mm×2 mm and operating in the first three modes, the corresponding input impedances Zin were evaluated at 665 Ω - 225 Ω and 1974 Ω, while the output impedances Zout were evaluated at 19.2 MΩ - 15.4 MΩ, and 1.8 MΩ. A voltage gain of 164, 179 and 23 at frequencies of 69.4 kHz, 136 kHz and 204.6 kHz, respectively was successfully measured, with a precision of less than 5%. In addition, a detailed equivalent circuit of the transformer was built and all its lumped RLC components were experimentally identified using the Nyquist diagram showing, on the whole, a well-accepted agreement with the expected results.

The vocational training and education sector in Algeria faces numerous challenges due to its roles in both economic and social spheres. Therefore, this study aims to determine the extent of outstanding performance management practices in vocational training institutions in the state of Médéa, Algeria. The quantitative analytical approach was used on a sample of 21 vocational training institutions, relying on the questionnaire as a data collection tool, which was distributed to 51 (institution directors, sub-directors, and heads of departments). The study reached several results, the most important of which is the application of outstanding performance management in the studied institutions, where it was proven that the dimensions of performance management exist, and the institutions’ application of performance planning and feedback was at a high level. As for the institution’s application of the dimension of improving and developing performance and after measuring and evaluating performance, there was a medium level of application.

This study aimed to determine the appropriate timing for substituting live feed with artificial feed in the rearing of Channa striata larvae. The larvae at the age of 2 days after hatching (DAH) with an average initial length and weight of 6.27 ± 0.88 mm and 0.53 ± 0.01 mg, respectively, were used as the experimental biota. Larvae were randomly distributed into 16 containers, with a stocking density of 350 individuals per container. The study was conducted with four treatments, each with four replications. The larvae were co-fed Moina sp. and artificial feed at 6, 8, 10, and 12 DAH with a reduction of Moina sp. starting from 0.5% to 5.0%. The measured parameters showed the most favorable results when initiating artificial feeding at 12 DAH with survival rate of 89.52 ± 4.49%, and specific growth rate of 15.67 ± 0.25% per day with artificial feed conversion ratio of 51.79 ± 0.09. The enzyme activity and intestinal histology showed the effect of the co-feeding regime on intestinal development. Finally, the present study revealed that the weaning period for C. striata larvae could be conducted at 12–16 DAH and artificial feeding may be implemented at 17 DAH.