Secondary stress. A secondary stress is any stress in the structure which is not a primary stress or peak stress. Source: API SPEC 16R, Specification for Marine Drilling Riser Couplings, Exploration and Production Department, First Edition, January 1997. Global Standards.
Digger bees are sometimes classified in the family Anthophoridae along with the carpenter bees. These hairy bees range from 5 to 25 mm in length and, like other members of this family, the females use scopae (stiff hairs) to carry pollen. Most species nest in the ground or in vertical banks, often in sandy soil. Some species waterproof their brood cells with secreted waxy or oily material.
Races of Bees. Most common strains of bees are gentle enough to keep in a city. In the northern U.S., the Carniolan race is most popular. In the southern U.S. and Mexico, the Italian bee is preferred. If a colony is found to be inclined to sting, it should be requeened with gentle stock.