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Kubelka-Munk (KM) (two-flux) model was computed to solve the radiative transfer equation. The transmittance and reflectance spectra were calculated for Vanadium dioxide (VO 2) particulate film embedded in a polymer matrix. Numerical results in this work show a high similarity with experimental results reported in literature. The influence of particles concentration and thickness on the absorption coefficient K and temperature dependence of VO 2 transmittance were verified. A comparison with a four-flux model confirms the exactitude of our results. Calculations were done in the 300-2500 nm solar optical wavelength range for several particles concentration values of 1, 0.5, 0.25 and 0.1 and several thicknesses for two values of temperature 22°C and 100°C under and above (VO 2) Transition.

Abstract-Radiative rectification is one of the newest solutions for thermal building insulation. It is a phenomenon which has good analogy with electronic diode principle. It consists on being blocking for solar radiations in summer and passing radiations in winter. Among materials which have rectification capacity, Vanadium dioxide (VO 2 ) offers good applicability to building insulation with quite good rectification efficiency. VO 2 has a transition temperature around 68°C. Under this temperature, the material has a semiconductor crystallographic structure; therefore it becomes transparent to visible and infrared solar spectra. Above 68°C, the crystallographic structure of VO 2 changes to a metallic state for which it becomes more reflective to the same spectra. This semiconductor/metallic transition influences the optical properties of VO 2 which are highly dependent to temperature and wavelength. These properties are refractive index n(T,λ) and extinction coefficient k(T,λ), they are necessary in the optical study of VO 2 insulation capacities. Determination of these properties is purely experimental using ellipsometry techniques. In this work we suggest a method for numerical determination of these optical properties. This method uses the Particle Swarm Optimization (PSO) algorithm and it is based on the theoretical model of Lorentz oscillators at VO 2 nanoparticles scale. We calculated n(T,λ) and k(T,λ) for 3 temperatures and compared them with experimental results. This comparison showed good agreement between numerical and experimental results.Vanadium-dioxide, radiative rectification, building insulation, optical properties, optimization algorithms. I. INTRODUCTION Vanadium dioxide is a metal oxide that attracts many research teams over the world. It offers thermo-chromic properties depending on its semiconductor/metallic phase transition around 68°C [1,2]. VO 2 has many potential applications as a photonic device. In our case, we are trying to use VO 2 as a smart solution for radiative rectification applied to thermal building insulation, a smart solution because of its thermo-chromic properties highly dependent to temperature. At temperatures less than 68°C, VO 2 has a semiconductor crystallographic structure, with inter-atomic distances which allow high radiative transmission. Above 68°C, VO 2 switches to a metallic structure with small inter-atomic distances, thus VO 2 become more reflective to solar radiations. VO 2 is proposed for application to building glazing as smart window coatings by C.G. Granqvist et al [3]. The transition temperature too high compared with the comfort temperature is one of the limitations for smart windows application. G.V. Jorgenson et al [4] and W. Burkhardt et al [5] proposed a solution to decrease the VO 2 transition temperature by doping with some materials such as tungsten (W), Fluoride (F) and Molybdenum (Mo) with calculated concentrations to adjust the transition temperature around 25°C. The second limitation is related to high absorption in the visible part of sol...

Extractive industries often use explosives to destroy rocks, and productivity requirements tend to increase the charges of the explosives. The blasts induce vibrations, which result in a potential damage of the surrounding structures. Therefore, the prediction of vibrations should be described with accuracy, in order to ensure the safety of engineered structures. However, the prediction of vibrations’ levels remain a complicated issue, because it involves numerous parameters correlated to the quarry site. In this paper, statistical analysis based on the peak particle velocity (PPV) and the attenuation law has been carried out to assess the safety charges (Q) for different distances (R) between the blast and the considered structure to secure. Moreover, the experimental investigations were conducted on the quarry site of “Sococim”, which is located on the south coast of Senegal. To ensure the safety of the “Conveyor belt” and “Panel 1 (Upper exploitation level)” sites, the PPV should be less than 10 mm/s. In fact, the attenuation model has been used to assess the safe charge weights of the explosive (Q) to be used at the “Conveyor belt” site and at the “Panel 1 (Upper exploitation level)” site. Therefore, the safe charge weights per delay (Q) were respectively 116 kg and 13.75 kg.