Destoner is a form of separator that separates the: (A) Feed... | Agrigyan

Calculation of Rankine's Lateral Pressure Coefficient:

• Formula: Rankine's active lateral pressure coefficient ($k$) for granular grain stored in a shallow bin is given by:
  $$k = \frac{1 - \sin\phi}{1 + \sin\phi}$$
  where $\phi$ is the internal angle of friction of the stored grain mass.
• Substituting $\phi = 30^\circ$:
  $$\sin(30^\circ) = 0.5$$
  $$k = \frac{1 - 0.5}{1 + 0.5} = \frac{0.5}{1.5} = \frac{1}{3} \approx 0.333$$

Analysis of Parboiling Effects on Rice Rancidity:

• Assertion (A) is False: During parboiling, steaming and soaking cause lipid migration into the endosperm and disrupt cellular oil bodies. Although parboiling inactivates lipolytic enzymes (preventing hydrolytic rancidity), parboiled rice and parboiled bran develop oxidative rancidity and off-odors much faster than raw milled rice during extended storage.
• Reason (R) is True: High processing temperatures during the parboiling hydrothermal treatment decompose and destruct heat-sensitive natural antioxidants (such as tocopherols, tocotrienols, and gamma-oryzanol) present in the bran and germ, removing natural oxidation protection.

Derivation of Reverse Carnot Refrigerator COP:

• Definition of COP: The Coefficient of Performance of a refrigerator is the ratio of heat absorbed from the cold refrigerated space ($Q_1$) to the net work input ($W$):
  $$\text{COP} = \frac{Q_1}{W} = \frac{Q_1}{Q_2 - Q_1}$$
• For a reversible Carnot cycle operating between absolute temperatures $T_1$ (evaporator/low) and $T_2$ (condenser/high):
  $$\frac{Q_1}{Q_2} = \frac{T_1}{T_2}$$
  Substituting temperatures yields:
  $$\text{COP}_{\text{ref}} = \frac{T_1}{T_2 - T_1}$$
  (Note: $T_2 / (T_2 - T_1)$ is the COP of a heat pump, whereas $(T_2 - T_1) / T_2$ is the thermal efficiency of a Carnot heat engine).

Criteria for Shape Description in Agricultural Process Engineering:
According to N.N. Mohsenin (Physical Properties of Plant and Animal Materials), the shape of grains, fruits, and seeds is characterized using several scientific criteria:

• Roundness: Measures the sharpness of the corners of a solid particle ($A_p / A_c$).
• Sphericity: Ratio of the diameter of a sphere of the same volume as the object to the diameter of the circumscribed sphere.
• Charted standards: Visual comparison with standard USDA / ASAE pictorial silhouette charts defining shapes like oblate, prolate, oblong, conic, and ovate.
• Resemblance to geometric bodies: Approximating the object shape with standard geometric solids such as prolate spheroid, oblate spheroid, right circular cylinder, or ellipsoid.