Constantine 1 University

Magnetic refrigeration is emerging as a major eco-friendly alternative to traditional cooling systems based on polluting gases. This work provides a comprehensive review of the state of the art in magnetic refrigeration prototypes based on the magnetocaloric effect. The paper analyzes the evolution of thermal performance, energy efficiency, and regenerator geometry across various developed designs, evaluating their actual cooling capacity. Furthermore, the article highlights the economic and technical barriers related to different magnets and heat transfer fluids in different machine architectures, including rotary and linear configurations. Finally, a particular emphasis is placed on the transition of laboratory prototypes toward viable commercialization in competition with vapor compression systems.

Flexible and multifunctional ultraviolet–visible (UV–Vis) photodetectors are highly desirable for next-generation wearable healthcare devices. In this work, we report novel PVC/n-ZnO/p-MxOy (M = Ni, Cu, Ag) heterojunction composite films designed as broadband photodetectors with additional antibacterial functionality. The ZnO/MxOy composites were synthesized via a hydrothermal method and embedded within a polyvinyl chloride (PVC) matrix to yield flexible films. Structural, morphological, and optical characterizations (XRD, FTIR, SEM, EDX, UV–Vis) confirmed high-purity heterojunction formation, good crystallinity, and homogeneous morphology, with broad absorption (200–800 nm) and tunable bandgaps (1.4–3.24 eV) due to the presence of secondary metal oxides (NiO, CuO, Cu2O and Ag2O) alongside ZnO. Antibacterial activity was evaluated using the agar diffusion method, revealing strong inhibition against Gram-positive bacteria (Bacillus and Staphylococcus aureus). Photodetection performance was studied via current–voltage (I–V) measurements under dark, UV, and visible light. All devices exhibited rectifying behavior, confirming efficient n–p heterojunction formation. Among the tested devices, the PVC/ZnO/Ag2O heterojunction exhibited superior performance, achieving a responsivity of 12.7 µA/W and a detectivity of 3.08 × 10⁸ Jones under UV illumination at 5 V bias. I–t measurement revealed stable and repeatable switching, with rise and decay times of 85 s and 130 s, respectively. The device also demonstrated outstanding long-term reliability, maintaining 97

The aim of the current study is assessing the in vitro anti-inflammatory and antioxidant properties of Laurus nobilis methanolic extract (LNME) and to investigate their impacts on experimental oxidative stress in ulcerative colitis caused by acetic acid (AA). The in vitro antioxidant ability of LNME was evaluated using four tests (DPPH, ABTS, FRAP, and CUPRAC). The anti-inflammatory capacity was assessed using the protein denaturation technique, on the basis of total polyphenol measurement. In an in vivo study, 28 rats were equitably divided into four groups: (1) control group, (2) Laurel group: Rats receiving 250 mg/kg B.W of LNME, (3) AA group: Rats receiving 2 mL/kg B.W of AA (3 The current study suggests that LNME displays anti-inflammatory, and antioxidant potential and a cytoprotective impact supporting its uses to alleviate ulcerative and colonic oxidative stress.

This study investigates the enhancement of the thermal, structural, and optical properties of elastomeric polyolefin (POE)/phase change material (PCM(C25H52)) composite polymers through the incorporation of zinc oxide (ZnO) nanoparticles, targeting applications in thermal energy storage, photovoltaics, and encapsulation. Composites were prepared with varying ZnO doping levels (0%, 10%, and 30%) and characterized using differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. The results demonstrate that the addition of ZnO nanoparticles significantly improves thermal stability, energy storage capacity, and heat transfer efficiency. The 30% ZnO-doped composite exhibited the highest melting temperature (90.5 degrees C), no mass loss up to 180 degrees C, and the greatest thermal conductivity, making it a promising candidate for thermal energy storage and encapsulation. X-ray diffraction analysis confirmed the successful incorporation of ZnO nanoparticles and an increase in crystallinity with doping, while photoluminescence spectra revealed enhanced optical properties due to defect passivation. The POE/PCM(C25H52) matrix provides a stable environment that preserves the intrinsic properties of ZnO nanoparticles, enabling their effective integration into the composite. These findings highlight the potential of ZnO-doped POE/PCM(C25H52) composites for advanced applications in thermal energy storage, heat management, opto electronics, and encapsulation particularly in photovoltaic systems, where uniform dispersion of ZnO nanoparticles can enhance light absorption, charge transport, and device durability.

Securing and tracing medical audio data is crucial in telemedicine and digital archiving. This paper presents a blind and irreversible audio watermarking scheme designed to satisfy imperceptibility, robustness, and embedding capacity requirements for sensitive medical applications. The method integrates the Fractional Charlier Transform (FrCT) for adaptive time-frequency analysis, local entropy analysis with the Watson perceptual model for intelligent coefficient selection, and adaptive logarithmic quantization index modulation (LQIM) for embedding. It securely incorporates patient and acquisition metadata, ensuring confidentiality and integrity via cryptographic and error-correction techniques. Experiments demonstrate a payload of 67.3 bits per second, high audio transparency (SNR > 36 dB, PESQ > 4.0), and robustness against various signal processing attacks (average BER 4.5