Compressive strength is measured on materials, components, and structures. By definition, the ultimate compressive strength of a material is that value of uniaxial compressive stress reached when the material fails completely. The compressive strength is usually obtained experimentally by means of a compressive test.y definition, the ultimate compressive strength of a material is that value of uniaxial compressive stress reached when the material fails completely. The compressive strength is usually obtained experimentally by means of a compressive test.
VX is the deadliest nerve agent ever created. Known by its U.S. Army code name, it is a clear, colorless liquid with the consistency of motor oil. A fraction of a drop of VX, absorbed through the skin, can fatally disrupt the nervous system. Although a cocktail of drugs can serve as an antidote, VX acts so quickly that victims would have to be injected with the antidote almost immediately to have a chance at survival. VX is the only significant nerve agent created since World War II.
The organophosphate nerve agents tabun (GA), sarin (GB), soman (GD), and cyclosarin (GF) are among the most toxic chemical warfare agents known. Together they comprise the G-series nerve agents, thus named because German scientists first synthesized them, beginning with GA in 1936. GB was discovered next in 1938, followed by GD in 1944 and finally the more obscure GF in 1949. The only other known nerve agent, O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX), is discussed in a separate article of this journal (see CBRNE-Nerve Agents, V-series-Ve, Vg, Vm, Vx). G-series nerve agents share a number of common physical and chemical properties. At room temperature, the G-series nerve agents are volatile liquids, making them a serious risk for 2 types of exposure: dermal contact with liquid nerve agent or inhalation of nerve agent vapor.