Tubular surfaces
Step 1: Understanding the structure of a calandria. - A calandria is a type of heat exchanger commonly used in evaporators and boilers. - It consists of multiple tubular surfaces, which enhance heat transfer efficiency by increasing the contact area.
Step 2: Explanation of incorrect options. - (A) Baffles: Used in shell-and-tube heat exchangers, not a defining feature of a calandria. - (B) Jackets: Found in jacketed vessels, not calandria. - (C) Outlets: Necessary for fluid flow but not a structural characteristic.
Step 3: Selecting the correct option. Since calandria primarily consists of tubular surfaces for efficient heat exchange, the correct answer is (D) Tubular surfaces.
A closed-loop system has the characteristic equation given by: $ s^3 + k s^2 + (k+2) s + 3 = 0 $.
For the system to be stable, the value of $ k $ is:
A digital filter with impulse response $ h[n] = 2^n u[n] $ will have a transfer function with a region of convergence.