In this work, we present a study of heat transfer through the different layers of a frequency modulated pavement structure. Solving the heat equation for the different layers obtained the temperature and the heat flux density of each layer (from the wearing course to the base layer) of the structure. The expression of the equivalent thermal impedance of the wearing course in crushed plastic bag waste and sugar cane residue, found by thermal electrical analogy, allowed to study the diagrams of Bode, its phase and his portrayal of Nyquist. These studies are carried out in the illumination zone and in the shaded zone.
The objective of this study is to characterize the solid household waste of the city of Thiès and to propose ways of valorization. In order to carry out this study, a physical characterization campaign was carried out using the household waste characterization method (MODECOM) modified and adapted to the national context. The results of this campaign revealed that the fines represent more than 50% of the flow emitted by the medium and low standing. For the high standings, this fraction represents only 40%. Putrescibles (between 5% and 20% depending on the standing), plastics, cardboard, composites and paper are the most produced by the population. Similarly, the granulometry is dominated by the fraction of fines followed by the average diameters. The daily ratio is 0.528 kg/capita/day.The main characteristics determined during the physicochemical characterization are the carbon-nitrogen ratio (27), the chemical oxygen demand (263.8 mg/g), the biodegradability (3) and the methanogenic potential (312.69). The methanization of this waste produced a biogas with a maximum methane content of 41%. This methanization was controlled by monitoring two main parameters which are temperature and pH.
It is essential to know the desorption isotherms to control the drying processes of agricultural products, food. The objective of this work is to determine the sorption isotherms of the local onion: the Violet de Galmi cultivated in the Niayes area. Desorption isotherms were studied for water activities ranging from 0.05 to 0.9 and for temperatures of 40 °C, 50 °C and 60 °C using the static gravimetric method. Six saturated salt solutions were used (KOH, K2CO3, NaBr, CuCl2, KCl and NaCl). The results show that the desorption isotherms of onion are type II and the equilibrium water content is temperature dependent. The experimental results are then smoothed by five models: Guggenheim - Anderson - De Boer (GAB), Brunauer - Emmett and Teller (BET), Henderson, Oswin and Peleg for the description of the equilibrium state of this product. From the modeling, it was concluded that both the Peleg model and the GAB model describe the desorption isotherms of onion well, but the Peleg model has the smallest relative errors, thus defining the Peleg model as the best model. From the results obtained, the isosteric heat of desorption is determined using the Clausius-Clapeyron equation.
In this study, we propose an evaluation method of the thermal inertia for two adjoining materials to one another from the heat capacity. The expression of the capacity has been deducted from the thermal-electrical analogy in dynamic frequency regime. The influences of the exciting pulse and depth in the concrete slab and in the tow-plaster on the heat capacity were presented.
In this paper, we propose a study of heat transfer through a roadway. The expression of the temperature and heat flux density are obtained from the resolution of the heat equation and the Fourier law in dynamic frequency regime. The influence of extrinsic parameters such as coefficients of convective and radiative heat exchange and cloud cover are presented.