Phenology is the study of recurring plant and animal life cycle stages, or phenophases, such as leafing and flowering of plants, maturation of agricultural crops, emergence of insects, and migration of birds. Many of these events are sensitive to climatic variation and change, and are simple to observe and record.
Polychlorinated biphenyls (PCBs) are a group of manmade chemicals. They are oily liquids or solids, clear to yellow in color, with no smell or taste. PCBs are very stable mixtures that are resistant to extreme temperature and pressure.
The CCB is a brake disc made from a core of ceramic material reinforced with carbon fiber with an additional ceramic layer on both the friction surfaces.o produce carbon-ceramic brake disks, we use carbon fibers which are given a special protective coating and then cut into short fiber sections of defined thickness and length. The fiber can be used directly or can be treated in order to obtain a complex row material called âcarbochipâ.