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.
Theories of Early Childhood: Maria Montessori, Erik Erikson, Jean Piaget, and Lev Vygotsky. Montessori: Maria Montessori was born in Italy in 1870. In her work at the University of Rome's psychiatric clinic, Dr. Montessori developed an interest in the treatment of children and for several years wrote and spoke on their behalf. At age twenty-eight, she became the director of a school for mentally-disabled children.