The range of the radar horizon dependson the height of the antenna and on the amount of bending of the radar wave.The bending is caused by diffraction and refraction. Diffraction is a propertyof the electromagnetic wave itself. Refraction is due to the prevailingatmospheric conditions.
Anaerobic bacteria, or anaerobes, are bacteria that do not need oxygen to live. In humans, these bacteria generally live in the gastrointestinal tract, but they may also be found in other places outside the body, including in the soil and water, in foods, and in animals.
Aerobic bacteria thrive in the presence of oxygen and require it for their continued growth and existence. Other bacteria are anaerobic, and cannot tolerate gaseous oxygen, such as those bacteria which live in deep underwater sediments, or those which cause bacterial food poisoning. The third group are the facultative anaerobes, which prefer growing in the presence of oxygen, but can continue to grow without it.