Broadband communication satellites in Ka-band commonly use four reflector antennas to generate a multispot coverage. In this paper, four different multibeam antenna farms are proposed to generate the complete multispot coverage using only two multibeam reflectarrays, making it possible to halve the number of required antennas onboard the satellite. The proposed solutions include flat and curved reflectarrays with single or dual band operation, the operating principles of which have been experimentally validated.
View Article and Find Full Text PDFMaternal mortality ratio in Ecuador is the only millennium goal on which national agencies are still making strong efforts to reach 2015 target. The purpose of the study was to process national maternal death databases to identify a specific association pattern of variable included in the death certificate. The study processed mortality databases published yearly by the National Census and Statistics Institute (INEC).
View Article and Find Full Text PDFThe purpose of this study is to determine the effectiveness of a group cognitive-behavioral treatment to modify coronary-prone behaviors in patients from a fairly low social and educational level. Participants were 98 male coronary patients randomly allocated to one experimental and two control groups. All groups received standard medical treatment.
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