For a steel alloy it has been determined that a carburizing heat treatment of 20 h duration at 827°C will raise the carbon concentration to 0.42 wt% at a point 3.9 mm from the surface. Estimate the time necessary to achieve the same concentration at a 7.2 mm position for an identical steel and at a carburizing temperature of 1040°C. Assume that D0 is 4.5 × 10-4 m2/s and Qd is 105 kJ/mol.

the correct answer is c.stops after infancy and childhood.

myelin is the substance of the central nervous system (cns) that insulates nerve cell axons to increase the speed at which nerve impulse travels. myelination is a process of myelin formation. this process occurs postnatally, begins in the embryo during the midst of early development and finishes after birth.

b. check your rearview mirror

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answer:

true

explanation: