This work focuses on traditional ovens used in several regions, notably in Benin, for the production of wheat flour pancakes, soya croquettes and mini-croquettes, sweet breads and cakes. To provide some solutions to the many difficulties encountered by users of these ovens, this document proposes a simple and improved traditional oven integrating an automated system for controlling and regulating the internal temperature, cooking management and ventilation for fuel combustion. The objective of the work is to preserve the environment and the health of users of these traditional ovens. Specifically, it is firstly a question of replacing the wood used as fuel with palm nut shells and secondly of eliminating accidents, smoke inhalation and losses experienced by users of the oven. The oven is easily reproducible because it is built with locally available materials and non-complex techniques. Tests on the improved traditional oven carried out show that in four minutes of heating, the internal temperature rises to 300 °C. After stopping the ventilation system, thus stopping combustion, the temperature slowly decreases and drops to 100°C after a period of 1 hour 05 minutes. Keywords: Words: Oven, energy efficiency, deforestation, combustion, temperature regulation.
Context . Open clusters have been extensively used as tracers of Galactic chemical evolution, as their constituent stars possess shared characteristics, including age, Galactocentric radius, metallicity, and chemical composition. By examining the trends of elemental abundances with metallicity, age, and Galactocentric radius, valuable insights can be gained into the distribution and nucleosynthetic origins of chemical elements across the Galactic disk. The infrared domain in particular facilitates the observation of some elemental abundances that can be challenging or impossible to discern in the optical; for example, K and F. Aims . The objective of this study is to derive the stellar parameters and elemental abundances of up to 23 elements in 114 stars spanning 41 open clusters using high-resolution infrared spectroscopy. In addition, the present study aims to examine the chemical evolution of the Galactic disk. This is achieved by investigating radial abundance gradients, variations in abundance between clusters, and the dependence of chemical abundances on the cluster age. Methods . The spectra utilized in this study were obtained with the high-resolution near-infrared GIANO-B spectrograph at the Telescopio Nazionale Galileo. The derivation of stellar parameters and chemical abundances was achieved by employing the Python version of Spectroscopy Made Easy. In the H -band region, a combination of atomic and molecular features was utilized to constrain the stellar parameters, including OH, CN, and CO molecular lines, and Mg I, Si I, Ti I, Ti II, C I, and Fe I atomic lines. Results . Abundances for up to 23 elements, C, N, F, Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ce, Nd, and Yb, were derived and compared with available literature values where possible. Non-local thermodynamic equilibrium analysis was utilized for the elements C, Na, Mg, Al, Si, S, K, Ca, Ti, Mn, Fe, and Cu. For each element, Galactic trends were examined by analyzing both [X/Fe] and [X/H] as functions of [Fe/H], stellar age, and Galactocentric radius. In particular, the radial abundance gradient of Ytterbium is presented for the first time, thereby extending the observational constraints on heavy neutron-capture elements. Conclusions . Radial abundance gradients for a wide range of elements in the Galactic disk are found, with [X/Fe] slopes ranging from −0.061 to +0.065 dex/kpc. The observed gradients are consistent with an inside-out formation scenario for the Galactic disk, wherein chemical enrichment proceeds from the inner regions to the outer ones over time. The observed [X/Fe] trends across multiple nucleosynthetic groups, including α elements, odd-Z elements, iron-peak elements, and neutron-capture elements such as Y, Ce, Nd, and Yb, reflect the diverse production sites and timescales associated with each group. In particular, the positive [Zn/H] and [Zn/Fe] gradients suggest a distinctive nucleosynthetic origin for Zn, possibly linked to metallicity-dependent yields. The positive gradient in [Yb/Fe] (0.065 ± 0.031 dex/kpc) provides significant new constraints on neutron-capture enrichment processes and the chemical evolution of the Galactic disk.
For underground nuclear disposal repositories, sealing performance is crucial to ensuring long-term operational safety. Bentonite, widely employed as a sealing material, effectively reduces leakage risks owing to its self-healing capacity. However, a comprehensive investigation of gas migration mechanisms in bentonite is imperative to elucidate the underlying leakage dynamics. This study not only offers theoretical insights for the safety assessment and design optimization of disposal repositories but also holds substantial practical significance in ensuring their secure performance. To accurately model gas migration in saturated bentonite, this study systematically investigates the effects of pore pressure on soil deformation and experimentally evaluates the impact of damage evolution on permeability and elastic modulus. Building on these experimental insights, we propose a coupled fluid-solid constitutive model. This model elucidates the progressive development of microcracks within bentonite under increasing gas pressure, providing a mechanistic understanding of fracture propagation in sealing systems. By integrating experimental data from bentonite hydration and gas breakthrough tests, the study verifies that gas migration under flexible boundary conditions is primarily governed by the dilatancy effect of bentonite. Furthermore, the model's validity and applicability are demonstrated. Subsequently, the model is employed to systematically investigate the influence of confining pressure on (1) the evolution of microcracks in bentonite, (2) permeability variations, and (3) gas breakthrough pressure thresholds. Based on these analyses, theoretical mitigation strategies to prevent gas breakthrough are established for specific confining pressure ranges.
