The fundamental pitch of a CC tuba is 32 Hz, and for a BB â­ tuba, 29 Hz. The CC tuba is used as an orchestral instrument in the U.S., but BB â­ tubas are the contrabass tuba of choice in German, Austrian, and Russian orchestras.
Settlement: When a load is applied on the ground, it increases the vertical effective stress. This stress increases the vertical strain in the soil. This increase in vertical strain causes the ground to move downward. This downward movement of the ground is called settlement. Many civil engineering projects include placing of loads on the ground, which produces increase in vertical effective stress. This increase in vertical stress is important because it produces vertical strain in the soil. Subsidence:
(soil cultivation), the practice of working the soil to raise its fertility and to bring about better conditions for plant growth. Tillage breaks the topsoil up into loose, small clumps and improves the water, air, and thermal regimes of the soil. Microbiological processes are activated in the soil, and the fields are cleared of weeds, pests, and disease pathogens. During tillage, fertilizer is applied to the soil.