In natural water, hardness is mainly caused by

During a 6-hour storm the rainfall intensity was 0.8 cm/hr on a catchment of area 8.6 km². The measured runoff volume during this period was 2,56,000 m³. The total rainfall was lost due to infiltration, evaporation and transpiration in cm/hr is

A $$10m$$ long prestressing bed is used to cast $$4$$ (pretensioned) prestressed concrete beams of $$2.3$$ $$m$$ each. A schematic representation of the bed is given in the following figure. The continuous prestressing reinforced is pulled at the end $$'Y'$$ of the bed through a distance of $$20$$ $$mm$$ to introduce the required prestress, before the concrete is cast. After the concrete has hardened, the prestressing reinforcement is cut at points $$A,B,C,D$$ and $$E.$$ Assume that the prestress is introduced without eccentricity, what is the loss in prestress on account of elastic deformation of concrete. Assume $${E_s} = 200000\,\,N/m{m^2},$$ reinforcement is $$500\,\,m{m^2},$$ size of beams $$ = 200\,\,mm\,\left( b \right) \times 400\,\,mm\,\left( h \right).$$

As per provision of $$IS$$ $$456$$-$$2000$$, in the limit state method for design of beams, the limiting value of the depth of neutral axis in a reinforced concrete beam of effective depth $$'d'$$ is given as