Heartburn is often triggered by foods. This is because certain substances irritate the esophagus or weaken the lower esophageal sphincter (LES), which prevents the backward flow of stomach contents that causes reflux. Triggers can include: 1  alcohol. 2  caffeinated products, such as coffee, soda, and tea. 3  chocolate. 4  citrus fruits. 5  garlic. 6  fatty foods. 7  onions.
Testing specific gravity of fuel. Specific gravity is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.
Jason Eardley Vocabulary density specific gravity Specific gravity is the density of a substance relative to some reference substance: Specific gravity = density of substancedensity of reference substance Specific gravity was defined because it's convenient to have a unitless measure of density.The reference substance for solids and liquids is usually water at 4Â°C. At that temperature, water has a density of 1.0000 g/mL.pecific gravity is the density of a substance relative to some reference substance: Vocabulary. density specific gravity. Specific gravity =. density of substancedensity of reference substance. Specific gravity was defined because it's convenient to have a unitless measure of density.