Desempenho de dois equipamentos na colheita semimecanizada da cultura da mandioca Performance of two equipments in semi-mechanized harvesting of cassava

Estudou-se o desempenho operacional de dois equipamentos na colheita da mandioca. Um afofador do solo e um arrancador de mandioca foram avaliados. Analisaram-se a patinagem das rodas motoras, as perdas de produto, os danos mecânicos provocados às raízes e a capacidade de campo dos conjuntos trator-equipamento. Depois da passagem dos conjuntos, as raízes inteiras colhidas e que permaneceram no solo e com danos mecânicos, foram separadas e pesadas. O conjunto trator-arrancador apresentou melhor dinâmica de corte, penetração no solo e menor patinagem das rodas. Não foram observadas perdas de raízes para os conjuntos avaliados. Os equipamentos apresentaram semelhantes danos mecânicos às raízes. O conjunto trator-afofador apresentou capacidade de campo 25% superior ao conjunto trator-arrancador. Entretanto, como o conjunto trator-afofador não deixa as raízes expostas e não possui dispositivo de corte frontal da parte aérea das plantas, foi observado aumento de 32% no tempo necessário para as operações de corte e separação das raízes. O desempenho operacional do conjunto trator-arrancador foi superior ao conjunto trator-afofador.<br>The operational performance of two equipments for the cassava harvest was studied. A soil disaggregating implement and an up root implement were evaluated. The wheel slip, the losses, the mechanical damage caused in roots and the field capacity of the tractor-implement systems were analyzed. In each test, the whole roots and the roots with mechanical damages were separated and their mass were obtained. Tractor-up root system showed the best dynamic of cut and soil penetration, which was considered the smallest wheel slip. No root losses were observed for the two systems. Between implements there was not difference for mechanical damages caused in roots. The tractor-disaggregating implement system presented field capacity of 25% upper than tractor-up root system. However, as tractor-disaggregating implement system did not leave roots exposed and it did not have a frontal device of plant pruning, it was observed an increase of 32% on necessary time for cutting and roots separation. The tractor-up root system provided higher operational performance

GLONASS

The Global’naya Navigatsionnaya Sputnikova Sistema (GLONASS) is a global navigation satellite system developed by the Russian Federation. Similar to its US counterpart, the NAVSTAR global positioning system (GPS), GLONASS provides dualfrequency L-band navigation signals for civil and military navigation. Initiated in the 1980s, the system first achieved its full operational capability in 1995. Following a temporary degradation, the nominal constellation of 24 satellites was ultimately reestablished in 2011 and the system has been in continued service since then. This chapter describes the architecture and operations of GLONASS and discusses its current performance. In addition, the planned evolution of the space and ground segment are outlined