The diseases have been categorized as patches (cause dead spots or patches in the lawn), rings (cause rings of dead or affected grass), or leaf blight (affect individual blades of grass, often over a wide area and no distinct patch or ring pattern may be noticeable).
PVR, abbreviation for pulmonary vascular resistance. To measure changes in blood vessel size or changes in gas volume in the lungs to assist in diagnosing diseases such as deep vein thrombosis (DVT), chronic obstructive pulmonary disease (COPD), and some peripheral vascular disorders. Veins, arteries, and lungs. None.
Photovoltaics (PV) is the name of a method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon commonly studied in physics, photochemistry and electrochemistry.hotovoltaics (PV) is the name of a method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon commonly studied in physics, photochemistry and electrochemistry.