There are four different maintenance philosophies. which of them is the least effective and why?

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.

Describe briefly, the concept of mass production in modern industrial system.