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.
The usage of specific gravity notation is useful in the metric system, where the density of water is typically taken as 1000 kilograms per meter cubed. Multiplying the specific gravity of a material by 1000 yields the density of the material in kilograms per meter cubed. Dividing 1000 by itself yields the specific gravity of water, which is one. The larger the specific density of a material, the more dense the material is than water. Specific density can be used to determine whether solids of different materials float or sink in water. If the material specific gravity is greater than one, it sinks in water.