The performance characterization of a liquid metal magnetohydrodynamic alternate generator is num... more The performance characterization of a liquid metal magnetohydrodynamic alternate generator is numerically investigated via its electric isotropic efficiency. The model consists of a harmonically driven liquid metal oscillatory flow confined to a thin-walled closed rectangular duct interacting with a uniform magnetic field transverse to its motion and attached to a load resistance. Spectral collocation method is used to solve the properly boundary-conditioned Navier-Stokes equation under inductionless approximation for the magnetic field with implementation of gradient formulation for the electric field. Flow is considered fully developed in the direction perpendicular to the applied uniform magnetic field (i.e., motion direction), incompressible, viscous, and laminar in regime. Currently, there are neither purely analytical or experimental results on this problem, but ours were cross-referenced with those from a one-dimensional analytical model as close as possible to it, finding reasonable correspondence. Dimensional estimates on the power production of prospective mesoscale devices having in mind household application are provided for different liquid metals as well.
Turkish Journal of Agriculture - Food Science and Technology, 2017
Due to its nutritional and economic value, the tomato is considered one of the main vegetables in... more Due to its nutritional and economic value, the tomato is considered one of the main vegetables in terms of production and consumption in the world. For this reason, an important case study is the fruit maturation parametrized by its mass loss in this study. This process develops in the fruit mainly after harvest. Since that parameter affects the economic value of the crop, the scientific community has been progressively approaching the issue. However, there is no a state-of-the-art practical model allowing the prediction of the tomato fruit mass loss yet. This study proposes a prediction model for tomato mass loss in a continuous and definite time-frame using regression methods. The model is based on a combination of adjustment methods such as least squares polynomial regression leading to error estimation, and cross validation techniques. Experimental results from a 50 fruit of tomato sample studied over a 54 days period were compared to results from the model using a second-order polynomial approach found to provide optimal data fit with a resulting efficiency of ~97%. The model also allows the design of precise logistic strategies centered on post-harvest tomato mass loss prediction usable by producers, distributors, and consumers.
The performance characterization of a liquid metal magnetohydrodynamic alternate generator is num... more The performance characterization of a liquid metal magnetohydrodynamic alternate generator is numerically investigated via its electric isotropic efficiency. The model consists of a harmonically driven liquid metal oscillatory flow confined to a thin-walled closed rectangular duct interacting with a uniform magnetic field transverse to its motion and attached to a load resistance. Spectral collocation method is used to solve the properly boundary-conditioned Navier-Stokes equation under inductionless approximation for the magnetic field with implementation of gradient formulation for the electric field. Flow is considered fully developed in the direction perpendicular to the applied uniform magnetic field (i.e., motion direction), incompressible, viscous, and laminar in regime. Currently, there are neither purely analytical or experimental results on this problem, but ours were cross-referenced with those from a one-dimensional analytical model as close as possible to it, finding reasonable correspondence. Dimensional estimates on the power production of prospective mesoscale devices having in mind household application are provided for different liquid metals as well.
Turkish Journal of Agriculture - Food Science and Technology, 2017
Due to its nutritional and economic value, the tomato is considered one of the main vegetables in... more Due to its nutritional and economic value, the tomato is considered one of the main vegetables in terms of production and consumption in the world. For this reason, an important case study is the fruit maturation parametrized by its mass loss in this study. This process develops in the fruit mainly after harvest. Since that parameter affects the economic value of the crop, the scientific community has been progressively approaching the issue. However, there is no a state-of-the-art practical model allowing the prediction of the tomato fruit mass loss yet. This study proposes a prediction model for tomato mass loss in a continuous and definite time-frame using regression methods. The model is based on a combination of adjustment methods such as least squares polynomial regression leading to error estimation, and cross validation techniques. Experimental results from a 50 fruit of tomato sample studied over a 54 days period were compared to results from the model using a second-order polynomial approach found to provide optimal data fit with a resulting efficiency of ~97%. The model also allows the design of precise logistic strategies centered on post-harvest tomato mass loss prediction usable by producers, distributors, and consumers.
Uploads
Papers by Cesar Isaza