The TTL output stage is a rather complicated pushâpull circuit known as a totem-pole output (the transistors, diode, and resistor in the right-most slice of this TTL logic gate circuit). It sinks currents better than it sources current.
The theory for spontaneous generation refers to the idea that life can produced from nonliving things. Lazzaro Spallanzani proposed in his experiement that air was necessary for spontaneous generation.
Likewise, as Nutton (1990) tells us, in the sixteenth-century academic debates about contagion between Giambattista da Monte, professor of practice medicine at Padua, and Fracastoro, the âbad airâ theory of the non-contagionists could fit side-by-side with theories of contagion by other means.