University of Souk Ahras

This study investigates the temperature- and frequency-dependent ferroelectric and piezoelectric properties of undoped soft Pb(Zr0.52Ti0.48)O3 (PZT) ceramics synthesized via solid-state reaction. Fourier-transform infrared (FTIR) spectroscopy confirmed the formation of a perovskite structure through characteristic metal-oxygen bonds, indicating high purity. Direct Berlincourt measurements yielded an average piezoelectric coefficient d33 = 314 ± 9 pC/N, with a peak of 327 pC/N at 75°C, attributed to thermally activated domain wall motion. The piezoelectric voltage coefficient g33 and electromechanical coupling factor k33 reached maximum values of 0.0161 Vm/N and 0.573, respectively, at 75°C. Frequency-dependent measurements revealed that remanent polarization decreases from 0.109 C/m2 at 0.1 Hz to 0.035 C/m2 at 20 Hz, while the coercive field increases from 380 kV/m to 1050 kV/m. Rayleigh-type analysis quantified the logarithmic dependence of Pr on frequency (R2 = 0.934), indicating reduced domain wall mobility at higher frequencies. Energy loss density increased from 0.917 to 1.23 × 105 J/m3. Prandtl-Ishlinskii (PI) modeling accurately reproduced these behaviors (R2 > 0.98), enabling separation of reversible and irreversible polarization components. Thermal conductivity measurements showed a value of 1.30 W/m·K at room temperature. Furthermore, analysis of PZT under applied temperature gradients revealed limited electrical output, primarily arising from coupled thermo-mechanical and piezoelectric effects, while the majority of the input energy is dissipated through convection, radiation, and contact losses. This integrated experimental-modeling approach provides predictive understanding of PZT performance under varying operating conditions, offering practical guidance for the design of sensors, actuators, and energy harvesting devices.

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.

Toxoplasma gondii and Neospora caninum are heteroxenous apicomplexan parasites recognized as major causes of reproductive disorders in numerous mammalian species. The present study aimed to assess through an epidemiological survey, the prevalence of reproductive losses in 75 dromedary herds during the period 2022-2025, as well as the associated risk factors, and to detect these protozoa by histopathological analysis in 63 dromedaries slaughtered at the slaughterhouse of El Oued province (126 samples: 63 hearts and 63 diaphragms). The survey revealed that 80% of the herds had a history of abortions, of which 60% also reported cases of stillbirth. Risk factor analysis showed a significant association exclusively with the presence of domestic cats and dogs (P < 0.05). Histological examination revealed forms compatible with T. gondii exclusively in the cardiac muscle of adult females, with tachyzoites detected in one animal (1.6%) and tissue cysts in two animals (3.17%). No evidence of N. caninum was detected. Cardiac lesions were characterized by mononuclear cell infiltrates, focal hemorrhages and areas of necrosis, indicating marked inflammatory and vascular reactions. These findings suggest that T. gondii, may be involved in reproductive losses in dromedaries and effective parasite control strategies specific to dromedary camels need to be developed.

Ill-posed inverse problems are pervasive across scientific and engineering disciplines, with solutions highly sensitive to data perturbations. Among regularization strategies to mitigate this instability, iterative methods have proven effective. In this paper, we propose an accelerated iterative regularization strategy for solving ill-posed linear operator equations, inspired by nonstationary iterated Tikhonov regularization. The method incorporates a priori and a posteriori parameter selection rules, both of which yield optimal-order error estimates. Compared to existing iterative approaches, the proposed strategy significantly reduces the number of iterations required for convergence under suitable stopping criteria. Numerical experiments validate its efficacy, demonstrating robust performance in solving ill-posed problems. Furthermore, the method’s adaptability is showcased through applications to image restoration, highlighting its practical relevance.

This paper presents a systematic study of mild nonnegative solutions for iterative Caputo fractional totally nonlinear differential equations. First, we transform the differential equation into an integral formulation using the Laplace and inverse Laplace transform techniques. This reformulation enables us to rigorously investigate the fundamental properties of mild nonnegative solutions, including their existence, uniqueness and continuous dependence, as well as their Ulam-type stability. Leveraging the Krasnoselskii, Burton-Krasnoselskii and Banach fixed-point theorems, we establish novel existence and uniqueness results under appropriate conditions. To validate our theoretical findings, we conclude with two concrete examples that prove the applicability of the results.