The relationship between capital cost and capacity for industrial equipment often follows a power law, known as the scaling law. In this case, the cost-capacity relationship can be described by \( CC = k \times S^\beta \), where \( k \) is a constant and \( \beta \) is the cost-capacity factor.
Step 1: Understanding the Cost-Capacity Factor:
The value of \( \beta \) typically ranges between 0.6 and 0.8 for many types of industrial equipment, representing economies of scale. As the capacity increases, the increase in cost is less than proportional.
Step 2: Rule-of-Thumb for \( \beta \):
The most commonly used rule-of-thumb for \( \beta \) is 0.6, which suggests that as capacity doubles, the capital cost increases by approximately 60%, not doubling.
A hot plate is placed in contact with a cold plate of a different thermal conductivity as shown in the figure. The initial temperature (at time $t = 0$) of the hot plate and cold plate are $T_h$ and $T_c$, respectively. Assume perfect contact between the plates. Which one of the following is an appropriate boundary condition at the surface $S$ for solving the unsteady state, one-dimensional heat conduction equations for the hot plate and cold plate for $t>0$?

The following data is given for a ternary \(ABC\) gas mixture at 12 MPa and 308 K:

\(y_i\): mole fraction of component \(i\) in the gas mixture
\(\hat{\phi}_i\): fugacity coefficient of component \(i\) in the gas mixture at 12 MPa and 308 K
The fugacity of the gas mixture is _________ MPa (rounded off to 3 decimal places).
An electrical wire of 2 mm diameter and 5 m length is insulated with a plastic layer of thickness 2 mm and thermal conductivity \( k = 0.1 \) W/(m·K). It is exposed to ambient air at 30°C. For a current of 5 A, the potential drop across the wire is 2 V. The air-side heat transfer coefficient is 20 W/(m²·K). Neglecting the thermal resistance of the wire, the steady-state temperature at the wire-insulation interface __________°C (rounded off to 1 decimal place).

GIVEN:
Kinematic viscosity: \( \nu = 1.0 \times 10^{-6} \, {m}^2/{s} \)
Prandtl number: \( {Pr} = 7.01 \)
Velocity boundary layer thickness: \[ \delta_H = \frac{4.91 x}{\sqrt{x \nu}} \]