One of the most important standards that the API has set is the method used for measuring the density of petroleum. This standard is called the API gravity. Specific gravity is a ratio of the density of one substance to the density of a reference substance, usually water.
The most common symptoms of RSI include: 1  Pain. 2  Tingling. 3  A feeling of restlessness in the joint. 4  Weakness. 5  Throbbing. 6  Stiffness or cramp.
Inflammatory bowel disease symptoms vary, depending on the severity of inflammation and where it occurs. Symptoms may range from mild to severe. You are likely to have periods of active illness followed by periods of remission. Signs and symptoms that are common to both Crohn's disease and ulcerative colitis include:1  Diarrhea. 2  Diarrhea is a common problem for people with IBD. 3  Fever and fatigue. 4  Many people with IBD experience a low-grade fever. 5  You may also feel tired or have low energy. 6  Abdominal pain and cramping.ou are likely to have periods of active illness followed by periods of remission. Signs and symptoms that are common to both Crohn's disease and ulcerative colitis include: 1  Diarrhea. 2  Diarrhea is a common problem for people with IBD.