Tetracycline has been studied extensively in clinical trials, with thousands of people worldwide having been evaluated. In these studies, side effects occurring in a group of people taking the drug were documented and compared to the side effects that occurred in a similar group of people not taking the medicine.
Steel ties are utilised in nearly all sectors of the worldwide railroad systems including heavy-haul, class 1s, regional, shortlines, mining, electrified passenger lines (OHLE) and all manner of industries.
Railway tracks are generally laid on a bed of stone track ballast or track bed, in turn is supported by prepared earthworks known as the track formation. The formation comprises the subgrade and a layer of sand or stone dust (often sandwiched in impervious plastic), known as the blanket, which restricts the upward migration of wet clay or silt.