anal fistula (fistula in aÂ´no) one opening on the cutaneous surface near the anus, which may or may not communicate with the rectum. arteriovenous fistula one between an artery and a vein, either pathologic (such as a varicose aneurysm) or surgically created to ensure an access site for hemodialysis.
1 millibar (or hectopascal/hPa), is equivalent to 0.02953 inches of mercury (Hg). It is therefore only necessary to multiply a reading in millibars by the latter figure, to achieve the required conversion. E.g. for 1023 mbar, multiply by 0.02953=30.21 inches.
The two most common units in the United States to measure the pressure are Inches of Mercury and Millibars. Inches of mercury refers to the height of a column of mercury measured in hundredths of inches. This is what you will usually hear from the NOAA Weather Radio or from your favorite weather or news source. At sea level, standard air pressure in inches of mercury is 29.92. Millibars comes from the original term for pressure bar. Bar is from the Greek bÃ¡ros meaning weight. A millibar is 1/1000th of a bar and is approximately equal to 1000 dynes (one dyne is the amount of force it takes to accelerate an object weighing one gram, one centimeter, in one second). Millibar values used in meteorology range from about 100 to 1050. At sea level, standard air pressure in millibars is 1013.2. Weather maps showing the pressure at the surface are drawn using millibars. Although the changes are usually too slow to observe directly, air pressure is almost always changing.