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The Wadi Al-Baroud area, in Egypt’s Eastern Desert, exposes Neoproterozoic rocks of the Arabian-Nubian Shield (ANS), including both syntectonic granitoids (granodiorite and tonalite) and post-collisional granites. We present field work, petrographic study, mineral compositions, and whole-rock geochemistry results from these granitoids and discuss their petrogenesis, magmatic sources, evolution, and tectonic significance. The syntectonic granitoids show subduction affinity and an anomalous steep trend of K-enrichment that suggests assimilation of a granitic component during their evolution. The post-collisional granites form two plutons, on opposite sides of Wadi Al- Baroud, named here the Ras Baroud pluton (RBP) and the Abu Hawis pluton (AHP). They intruded the syn- tectonic granitoids with sharp intrusive contacts. The post-collisional plutons are devoid of mafic enclaves and are cut by very few dikes. They dominantly consist of biotite monzogranite that grades into muscovite mon- zogranite. The latter lithology hosts Nb-Ta oxide minerals (columbite, tantalite, and wodginite) displaying a variety of textural and compositional features. The cores are primary columbite-(Mn), whereas rims are over- grown or partly replaced by tantalite-(Fe) and wodginite due to late interactions with highly fractionated re- sidual melt. The highly-evolved AHP and RBP granites are typical of the post-collisional granitoids of the ANS, including high concentrations of rare earth elements (REE), Ta, Hf, Nb, Zr, Y, and Rb; elevated ratios of Ga/Al; and low contents of Sr, CaO, and MgO. Their geochemistry suggests that the parental magma of both plutons formed from an I-type tonalitic source rock that underwent partial melting during the thermal disturbance that followed a lithospheric delamination event during the post-collisional stage of the East African Orogeny. The variations in major oxide and trace element contents among individual samples of the AHP and the RBP cannot be explained as a liquid line of descent due to fractional crystallization; rather we interpret them as sampling variable proportions of an evolved liquid and the solid crystals in equilibrium with that liquid. 

The wide deployment of wireless sensor networks has two limiting factors: the power-limited sensors and the congested radio frequency spectrum. A promising way to reduce the transmission power of sensors, and consequently prolonging their lifetime, is deploying reconfigurable intelligent surfaces (RISs) that passively beamform the sensors transmission to remote data centers. Furthermore, spectrum limitation can be overcome by spectrum sharing between sensors and radars. This paper utilizes tools from stochastic geometry to characterize the power reduction in sensors due to utilizing RISs in a shared spectrum with radars. We show that allowing RIS-assisted communication reduces the power consumption of the sensor nodes, and that the power reduction increases with the RISs density. Furthermore, we show that radars with narrow beamwidths allow more power saving for the sensor nodes in its vicinity.