The present invention relates to compounds of formulae The compounds of the present invention are NMDA -receptor subtype blockers and are used in the treatment of diseases related to this receptor. In some embodiments, a baffle for use in semiconductor process chambers may include a body comprising aluminum nitride and a metal oxide binding agent, wherein a ratio of aluminum nitride to metal oxide on a surface of the body is greater than or equal to the ratio within the body. The capacitance of the moisture measuring element is then calculated from the two time constants or the two period durations, a value for the moisture level finally being ascertained from the capacitance. A first passage selectively connects the delivery vessel to the liquid-receiving device.