So how many stars are there in the Universe? It is easy to ask this question, but difficult for scientists to give a fair answer! Stars are not scattered randomly through space, they are gathered together into vast groups known as galaxies. The Sun belongs to a galaxy called the Milky Way.
Reverse osmosis. Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water.
EPA Method 8082 is the most common analytical method used for the analysis of PCB Aroclors and a short list of PCB congeners in samples of solids, sediments, tissues and liquids. This method uses a capillary dual column gas chromatography with electron capture detection (GC/ECD).