The invention provides compounds of general formula in which m, A, R1 and Ar have the meanings defined in the specification; a process for their preparation; pharmaceutical compositions containing them; a process for preparing the pharmaceutical compositions; and their use in therapy. A short wireless communication distance can be extended by switching tofrom a directional antenna and an omni-directional antenna of the mobile terminal according to a user setting. A substrate support comprising a support body is disposed in the chamber body. The axle of the pump member drives a vane wheel to pump fluid upward into the nozzle member. Also, because Hastelloy has the advantage of a low oxidation rate in comparison to stainless steel and titanium, there is less contamination buildup due to conditions such as electron beam bombardment.