Agricultural Structure and Process Engineering

Agricultural Structure and Process Engineering:

a. Concrete is usually defined as mixture of cement, sand coarse aggregate (gravel and water in correct proportions and thoroughly mixed so that upon setting, it forms rock-like mass).

b. The slump test is performed to measure the plasticity of the concrete.

c. Water: cement ratio by volume for hydration hardening of cement theoretically works out to be 0.08 but for practically, it is 0.66 to 1.0

d. Curing of concrete is the process of strengthening it through hydration (7 days)

e. Mortar: mixture of cement, sand and water, or lime, sand and water.

f. Compressive strength of concrete ranging between 300 to 700 kg/cm. Seasoning of wood is primary done to get rid of all the surplus sap and moisture, to avoid decay or affected by fungus.

g. Rankine formula/ Airy formula used for determination lateral pressure in shallow bins.

h. Janssen formula used for determination lateral pressure in deep bins.

i. LSU continuous flow dryer is most commonly used in India developed at Louisiana state University Baton Rouge, USA in 1949.

j. Aero and hydrodynamic properties such as Drag Coefficient and Terminal Velocity of agricultural products are important and required of air and water conveying systems and separation equipment.

k. Fourier law is used for heat transfer through conduction.

l. Moisture content (m.c.) of some of the crops at harvest and for safe storage

m. Angle of repose is the angle between the base and the slope of the cone formed on a free vertical fall of the granular material to horizontal plane Tilting top drafting table and circular platform is used for measurement of angle of repose.

n. Refrigeration – process of removal heat from a space at a temperature lower than the surrounding temperature. The principle of refrigeration is based on second law of thermodynamic.

o. Latent heat of fusion of water at atmospheric condition is 80 kcal and Latent heat of vaporization of water at atmospheric condition is 540 kcal.

p. Scalping refers to the removal of few large particles in an initial process e.g. scalper. ‘

q. Cleaning process generally means the removal of foreign and undesirable matter from desired grain/products as much as possible to ensure its purity e.g. cleaner. Cleaning is done on the basis of size, weight and length of impurities.