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.
Specific Gravity and Density tests can be used to identify a material or to follow physical changes in a sample. Specific Gravity and Density tests can also be used to indicate the degree of uniformity or variability among different sampling units or specimens, or to indicate the average density of a large item.ASTM Standards: 1  D1475.bout Specific Gravity & Density Determiniation. Specific Gravity is a measure of the ratio of the mass of a given volume of material at 23 Â°C to the same volume of water.