Determine protective boundaries for electrical equipment. NFPA 70E recommends Limited and Restricted Approach Boundaries to protect workers from electric shock, and a separate Arc Flash Boundary to protect them from burns in the event of an arc flash. Employees should keep outside these boundaries ...
As a result, electrical equipment may have to be worked on while it is energized. The danger and potential for injury while working on or near energized electrical equipment is called an arc flash hazard. An arc flash occurs when there is a failure or short circuit in the electrical ...
June's full moon is commonly known as the strawberry moon, a name that comes from the Algonquin Native American tribe in the northeastern U.S. and eastern Canada and refers to the region's strawberry harvesting season (not the moon's actual hue). ...
作者: I Arcavi 摘要: Studying invisible objects in space that are hundreds of millions of light years away may sound impossible. But, in recent years, astronomers have developed a new way to investigate a type of invisible and distant objects—super-massive black holes. Black holes are the ...
heart racing and blood rushing. That physical “flash” is the only benefit.The gift of fearis thinking of those fearful feelings as a flashing red light warning you: If you continue in this “idea” you will soon be immobilized and stupid – unable to think clearly, take action, nor fin...
The membrane attack complex (MAC) is one of the immune system’s first responders. Complement proteins assemble on target membranes to form pores that lyse pathogens and impact tissue homeostasis of self-cells. How MAC disrupts the membrane barrier remai
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