Esophageal pH monitoring developed a dependable external reference electrode. Using this technique to monitor esophageal acid exposure patients for periods up to 24 hours, DeMeester and Johnson were able to identify the most important parameters of esophageal acid exposure, and they developed a composite pH score to quantify gastroesophageal reflux. The initial 24-hour pH studies required hospitalization until the introduction of microcircuits in the 1980s that allowed portable esophageal pH monitoring in an outpatient setting. Gastroesophageal reflux disease (GERD) is a common disease in western countries. In the United States, 7% of the population experiences heartburn daily and 44% at least once a
Alkali soil applied as a source of Ca ions to replace the sodium at the exchange complex. Gypsum also reacts with sodium carbonate to convert into sodium sulphate which is a neutral salt and does not contribute to high pH. There must be enough natural drainage to the underground, or else an artificial subsurface drainage system must be present, to permit leaching of the excess sodium by percolation of rain and/or irrigation water through the soil profile. Calcium Chloride is also used to reclaim alkali soils. CaCl converts NaCO into NaCl precipitating CaCO. NaCl is drained off by leaching water. Spent acid