This present work solves the problem of initial shape influence on transfer during convective drying. A characteristic dimension is found for the cubic, cylindrical and spherical-shaped samples of the sweet potato. Th...This present work solves the problem of initial shape influence on transfer during convective drying. A characteristic dimension is found for the cubic, cylindrical and spherical-shaped samples of the sweet potato. This characteristic dimension corresponds to the diameter D for the sphere, to the edge a for the cube and the diameter = height D = H for the cylinder. Unlike the sphere where this characteristic dimension is perfect, the cubic and cylindrical shapes have space factors which are, among other things, angles and borders. By fixing the same characteristic dimensions, we end up with overlapping curves, showing identical and uniform transfers.展开更多
This paper concerns the calculation of equilibrium composition of plasma mixture Air Fe<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>...This paper concerns the calculation of equilibrium composition of plasma mixture Air Fe<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub> and CO in temperatures range 1000 K to 6000 K. We supposed that the plasma is at atmospheric pressure and at local thermodynamic equilibrium (ETL). In the Saharan zone, the aerosols are proven from desert dust and biomass fires. They are essentially composed of oxides of silicon, calcium, iron, aluminum and carbonaceous elements from biomass. Thus, air circuit breakers often operate in a polluted environment without specific protection. They can have abnormal behaviors and failures of cuts. We used Gibbs free energy minimization method to access the different numerical densities of chemical species as a function of temperature. These data are very important to calculate thermodynamic properties, transport coefficients and modeling electrical arc in circuit breakers. The results show that the dust brings many particles which have low dissociation and ionization energies. This leads to an increase in metallic elements and a strong increase in the numerical density of electrons which could have a detrimental effect during the current cut-off phase with the increase in the electrical conductivity of the plasma.展开更多
文摘This present work solves the problem of initial shape influence on transfer during convective drying. A characteristic dimension is found for the cubic, cylindrical and spherical-shaped samples of the sweet potato. This characteristic dimension corresponds to the diameter D for the sphere, to the edge a for the cube and the diameter = height D = H for the cylinder. Unlike the sphere where this characteristic dimension is perfect, the cubic and cylindrical shapes have space factors which are, among other things, angles and borders. By fixing the same characteristic dimensions, we end up with overlapping curves, showing identical and uniform transfers.
文摘This paper concerns the calculation of equilibrium composition of plasma mixture Air Fe<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub> and CO in temperatures range 1000 K to 6000 K. We supposed that the plasma is at atmospheric pressure and at local thermodynamic equilibrium (ETL). In the Saharan zone, the aerosols are proven from desert dust and biomass fires. They are essentially composed of oxides of silicon, calcium, iron, aluminum and carbonaceous elements from biomass. Thus, air circuit breakers often operate in a polluted environment without specific protection. They can have abnormal behaviors and failures of cuts. We used Gibbs free energy minimization method to access the different numerical densities of chemical species as a function of temperature. These data are very important to calculate thermodynamic properties, transport coefficients and modeling electrical arc in circuit breakers. The results show that the dust brings many particles which have low dissociation and ionization energies. This leads to an increase in metallic elements and a strong increase in the numerical density of electrons which could have a detrimental effect during the current cut-off phase with the increase in the electrical conductivity of the plasma.
