This research was conducted to evaluate 16 corn varieties cultivated for silage. The evaluation included: fodder production of green and dry matter, protein content and in vitro dry matter digestibility (IVDMD) and organic matter digestibility (IVOMD). A completely randomized design was used for statistical analysis and Tukey mean separation was used when appropiated. Fodder production as kg/ha was higher for AN446 (114028), AN445 (110993), and AN430R (106389). Dry matter fodder production was higher for AN447 (29270), AN461 (28026), VS373 (25434). Protein content (%) was higher for G4657 (7.58), AN388 (7.28), and AN448 (7.17). The best values for IVDMD (%)were for G1990 (69.14), AN446 (63.78), and AN430RR (63.50), while the higher values for IVOMD (%) were for G1990 (71.78), AN446 (65.20), and AN447 (65.12). Varieties AN446 and AN447 appeared frequently with the best values in the parameters evaluated, therefore, new research has to be performed with these varieties to confirm results found in this study.

In the last 15 years, Bogotá and Medellín, Colombia's two largest cities, have undergone urban renaissances. These are a direct result of a political will to tackle the social, economic and physical segregation caused by the large-scale urban migrations of the 1970s and 1980s, which resulted in informal developments that were often isolated from central urban areas with no infrastructure. Lorenzo Castro and Alejandro Echeverri describe the shared experiences and distinct approaches of each city.

Future aircraft and rotorcraft propulsion systems should be able to meet ambitious targets and severe limitations set by governments and organizations. These targets cannot be achieved through marginal improvements in turbine technology or vehicle design. Hybrid-electric propulsion is being widely considered as a revolutionary concept to further improve the environmental impact of air travel. One of the most important challenges and barriers in the development phase of hybrid-electric propulsion systems is the Thermal Management System (TMS) design, sizing and optimization for addressing the increased thermal loads due to the electric power train. The aim of this paper is to establish an integrated simulation framework including the vehicle, the propulsion system and the fuel-oil system (FOS) for assessing the cooling capability of the FOS for the more electric era of rotorcrafts. The framework consists of a helicopter model, propulsion system models, both conventional and hybrid-electric, and a FOS model. The test case is a twin-engine medium (TEM) helicopter flying a representative Passenger Air Transport (PAT) mission. The conventional power plant heat loads are calculated and the cooling capacity of the FOS is quantified for different operating conditions. Having established the baseline, three different Power Management Strategies (PMS) are considered and the integrated simulation framework is utilized for evaluating FOS temperatures. The results highlight the limitations of existing rotorcraft FOS to cope with the high values of thermal loads associated with hybridization for the cases examined. Hence, new ideas and embodiments should be identified and assessed. The case of exploiting the fuel tank as a heat sink is investigated and the results indicate that recirculating fuel to the fuel tank can enhance the cooling capacity of conventional FOS.