Lottia digitalis Point on the California coast, "L. digitalis" coexists with the similar species, "Lottia scabra", but each occupies a slightly different habitat. "L. digitalis" tends to occupy vertical rock faces or overhangs and certain horizontal ones clothed by algae and barnacles. "L. digitalis" clump together more often, prefer wave-exposed areas, occupy sites further up the shore and are seldom found in rock pools. Both species move about freely when the tide is up but "L. digitalis" settles in a different location at each low tide whereas "L. scabra" tends to home to the same spot. "L. scabra" has a more rugged
Chemical plant workers typically include engineers, plant operators, and maintenance technicians. Other personnel at the site could include chemists, management/administration and office workers. Types of engineers involved in operations or maintenance may include chemical process engineers, mechanical engineers for maintaining mechanical equipment, and electrical/computer engineers for electrical or computer equipment. Large quantities of fluid feedstock or product may enter or leave a plant by pipeline, railroad tank car, or tanker truck. For example, petroleum commonly comes to a refinery by pipeline. Pipelines can also carry petrochemical feedstock from a refinery to a nearby petrochemical plant. Natural gas is a product which comes