Larbi Ben M'hidi University of Oum El Bouaghi

In this work, we construct a multisecret-sharing scheme using codes over F-p constructed from symmetric designs. We also describe the access structure of the scheme and show its connection to the dual code. Furthermore, we formulate the number of minimal access elements. Finally, we explain the security of this scheme and provide an example over F-5.

The present study focuses on characterizing the different types of alteration, and the nature and origin of the fluids responsible for the deposition of Pb-Zn-Ba ores of three representative deposits in the Diapir Zone of northeastern Algeria. Petrographic and mineralogical data from the Ain Mimoun, Mesloula and Hameimat Nord ore deposits reveal two main phases of dolomitization: a replacement phase and a dolomitic cementation phase. The dolomitization process is accompanied by later ankeritization, locally followed by episodes of silicification and calcitization. These alterations gradually decrease with increasing distance from the Pb-Zn-Ba ore bodies towards the fresh host rocks. The studied hydrothermal carbonate minerals show high Sr contents in calcite III and ankerite from Ain Mimoun (619.66–1327.8 ppm) and Hameimat Nord (781.36–1116.3 ppm), indicating an Sr-enriched mineralizing fluid that locally deposited gangue celestite (SrSO₄) in these deposits. The enrichment in Zn, Cu, and Pb observed in ankerite samples from Ain Mimoun and calcite from Mesloula reflects the Zn-, Cu- and Pb-enriched fluids that deposited base-metal mineralization (galena, sphalerite and tennantite) in these localities. The δ¹³C values of the whole rock limestones in the three sites suggest a marine origin for carbon; whereas δ¹⁸O values (+ 24.2‰ to + 27.3‰) fall within to the isotopic composition range of the fresh Aptian-Albien facies in all the diapir zone of Algeria and Tunisia. The range of δ¹³C values observed in the hydrothermal calcite, dolomite and ankerite (varying between − 4 and + 4‰) remain within the range of marine carbonates, while the moderately low δ¹⁸O values (+ 18 to 24‰) compared to the host limestones reflect the influence of hydrothermal fluids, which are characterized by markedly low δ¹⁸O values (between + 9 and + 13‰), with the lowest values recoded in earliest hydrothermal carbonate minerals formed (dolomite), then ankerite and finally calcite showing the highest values. This study highlights the relevance of the present multidisciplinary approach in determining the origin, nature, and evolution of the fluids involved in the observed hydrothermal alterations in the MVT-like peridiapiric ore deposits of Eastern Saharan Atlas.

This work reports a dual-mode gas sensor based on vertically aligned TiO2 nanotube arrays fabricated by electrochemical anodization in an HF-based electrolyte and integrated into a planar Ag/TiO2/Ti metal–insulator–metal architecture. After annealing at 450 °C, the nanotubes crystallized in the anatase phase with uniform morphology, an inner diameter of 70–110 nm, a wall thicknesses of 15–20 nm, and abundant oxygen-vacancy defects, as confirmed by XRD and SEM analyses.The sensor simultaneously operates in resistive and capacitive modes during exposure to methanol, ethanol, 2-propanol, and acetone vapors in the 100–400 ppm range at room temperature, 100 °C, and 200 °C. Resistance decreases originate from redox reactions between VOC molecules and surface oxygen species, whereas capacitance increases result from dielectric polarization induced by polar molecule infiltration into the nanotube cavities. An Adsorption Dominance Factor (ADF = SR/SC) is developed to differentiate across adsorption mechanisms, categorizing them into chemisorption-dominated, physisorption-dominated, and mixed regimes. The temperature-dependent evolution of ADF indicates a transition from dielectric-controlled physisorption under ambient settings to charge-transfer-dominated chemisorption at higher temperatures, with ethanol exhibiting the most pronounced shift. Methanol demonstrates superior dual-mode performance, achieving resistive and capacitive responses of 76.31

This study investigates how to control chaos in discrete-time systems that have variable fractional orders. We examine a general type of discrete fractional-order equations where the order changes with time, and we show that these systems can become chaotic when certain parameters are chosen. To address this, we develop and apply tailored control techniques to suppress chaos and achieve system stabilization. Using detailed numerical simulations, we confirm that the suggested control method works effectively in two example cases. Our findings underscore that chaos control in variable fractional-order systems provides significant flexibility in modulating dynamic behavior, offering valuable insights into the broader applicability of these methods in discrete fractionalorder systems.

In this paper, we investigate a central coordinate system within the framework of the Wigner-Dunkl deformation of quantum mechanics in d spatial dimensions, focusing on the dynamics of a relativistic spinless particle described by the Klein-Gordon equation. The analysis is carried out using Feynman's path integral formalism in hyperspherical coordinates, where the Lagrangian includes an effective potential depending explicitly only on radial variables. This approach allows for the exact separation of variables in d-dimensional Dunkl space, enabling an analytical evaluation of the path integral. Particular emphasis is placed on the attractive Coulomb-type potential, for which the exact propagator is obtained in closed form. As a result, we derive the energy spectrum and corresponding wave functions of the Dunkl-Klein-Gordon system, expressed in terms of special functions that reflect the modified symmetries induced by the Dunkl operators.