Examples of devices that accept both 802.3af and Cisco power: Examples of devices that only accept 802.3af power: The presence of a gigabit Ethernet port on a powered device is a clear indicator that the device is 802.3af only. Because of the relative newness of PoE+, few devices require this level of power.
BHT or butyl hydroxytoluene is a fat soluble synthetic compound which is commonly used to preserve foods and cosmetics to slow down the autoxidation rate of ingredients in a product that can cause changes in the taste or colour.
Chemical properties are observable characteristics of the makeup of a substance. Observable does not necessarily mean that one can visually see it; rather it means that we can note the result. We can observe a smell, a voltage, or even a time.