Abstract—In this work, theoretical analysis and numerical results are given for time-reversal (TR) focus gains of polarization-varying electromagnetic fields in a rectangular resonant cavity. To demonstrate the gains in different polarization states of the static transceivers and the ones of the rotatable transceivers, the 3 dB attenuation areas of TR angle gain (AG) and AG flatness are first c...

A new species of Dorstenia L. (Moraceae), Dorstenialuamensis M.E.Leal, is described from the Luama Wildlife Reserve, west of Lake Tanganyika and north of the town of Kalemie in the eastern part of the Democratic Republic of Congo (DRC). This species is endemic to the region and differs from any of the other species by its fernlike lithophytic habit and lack of latex. A description and illustrat...

The family Pteridaceae in Iraq comprises 6 species belongs5 genera. These occur a diverse range of environments including humid temperate forests, the falls waterfalls and shrub lands. fern was collected from different locations environment geographical habitats during seasons two districts Iraqi Kurdistan. anatomical structure aerial parts were studied. Fronds petiole rachis (midribe) exhibitY...