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.
Some solitary bees also collect nest material from flowers such as Stachys bzantina (Lambsâ ear). Bees like blue, purple, violet and white flowers best, grown in large clumps in a sunny, sheltered spot. They do not like double headed varieties whose nectar and pollen has often been bred out.