On 16 July 1945, the first atomic bomb was detonated at the Alamogordo Bombing range in New Mexico, USA. Swept up into the nuclear cloud was the surrounding desert sand, which melted to form a green glassy material called 'trinitite'. Contained within the glass are melted bits of the first atomic bomb and the support structures and various radionuclides formed during the detonation. The glass itself is marvelously complex at the tens to hundreds of micrometre scale, and besides glasses of varying composition also contains unmelted quartz grains. Air transport of the melted material led to the formation of spheres and dumbbell shaped glass particles. Similar glasses are formed during all ground level nuclear detonations and contain forensic information that can be used to identify the atomic device.At 05:29:45 am local time on Monday, 16 July 1945, the nuclear age began. In a most graphic example of Einstein's famous equation (E = mc 2 or the original form m = L/V 2 where L = mass and V = the speed of light) a plutonium bomb, referred to as the 'Gadget', with a yield of 21 kilotons (equivalent to the explosive power of 21 000 tons of TNT) was detonated ( Fig. 1) at the Alamogordo Bombing range, 210 miles south of Los Alamos, New Mexico. The genie was out of the bottle and has been our uneasy companion ever since. One of the products of this nuclear explosion was a green glassy material formed by melting of the surrounding desert sand. Robert Oppenheimer had chosen the name 'Trinity' for the nuclear test and the name 'trinitite' was adopted for this green glassy material. The nuclear explosionThere are two fissionable isotopes (U-235 and Pu-239) that can be used to make atomic (fission) bombs. In both cases the basic principle is the same. A neutron interacts with a nucleus which leads to an increase in atomic mass and an unstable nucleus that splits into several pieces (fission fragments) + neutrons with a concomitant release in energy due to a loss in mass. The 235 U fission reaction is: U-235 + neutron → U-236 → fission fragments + neutrons + energyThe ejected neutrons cause further fission events leading to a chain reaction. For an explosive nuclear reaction billions of fission events need to occur in microseconds. The key is to have a sufficient mass of U-235 or Pu-239 in close proximity for this explosive reaction to occur.Two types of nuclear weapons were developed near the end of World War II. One, the 'gun type' consisted of an enriched uranium (U-235) bullet that was fired at an enriched uranium spike. The impact of these two pieces of enriched uranium produced the necessary mass density for a thermal nuclear explosion. Physicists were convinced that this type of bomb would work and only one was built and subsequently dropped on Hiroshima, on 6 August 1945. Fig. 1. The only known colour photograph of the Trinity Test.
Trinitite is the glass formed during the first atomic bomb test near Socorro, New Mexico, on July 16, 1945. The protolith for the glass is arkosic sand. The majority of the glass is bottle green in color, but a red variety is found in the northern quadrant of the test site. Glass beads and dumbbells, similar in morphology to micro-tektites, are also found at the Trinity site. The original description of this material, which appeared in American Mineralogist in 1948, noted the presence of two glasses with distinctly different indices of refraction (n = 1.46 and 1.51-1.54). Scanning electron microscopy (SEM) and Quantitative Evaluation of Minerals by SCANning electron microscopy (QEMSCAN) analysis is used to investigate the chemical composition and fine-scale structure of the glass. The glass is heterogeneous at the tens of micrometer scale with discrete layers of glass showing flow-like structures. The low index of refraction glass is essentially SiO 2 (high-Si glass), but the higher index of refraction glass (low-Si glass) shows a range of chemical compositions. Embedded in the glass are partially melted quartz (α-quartz as determined by X-ray diffraction) and feldspar grains. The red trinitite consists of the same two glass components along with additional Cu-rich, Fe-rich, and Pb-rich silicate glasses. Metallic globules are common in the red trinititeIn terms of viscosity, the high-Si and low-Si glasses differ by several orders of magnitude, and there is minimal mixing between the two glasses. QEMSCAN analysis reveals that there are several chemical subgroups (that can be characterized as simple mixtures of melted mineral components) within the low-Si glasses, and there is limited mixing between these glass subgroups. The red trinitite contains regions of Fe-rich glass, which show sharp contact with surrounding Fe-poor glass. Both the textural and chemical data suggest that these two glasses existed as immiscible liquids. The metallic droplets in the red trinitite, which consist of variable amounts of Cu, Pb, and Fe, show textural evidence of unmixing. These metals are largely derived from anthropogenic sources-Cu wire, Pb bricks, and the steel tower and bomb casing. The combination of mineralogical and chemical data indicate that temperatures on the order of 1600 °C and pressures of at least 8 GPa were reached during the atomic detonation and that there was a reducing environment during cooling, as evidenced by the presence of native metals, metal sulfides, and a low-Fe 3+ /Fe 2+ ratio. Independent estimates of maximum temperature during the detonation are on the order of 8000 K, far higher than suggested by the mineral data. This discrepancy is probably due to the very short duration of the event. In all respects, the trinitite glasses are similar to tektites and fulgurites, and by analogy one conclusion is that temperature estimates based on mineralogical observations for these materials also underestimate the maximum temperatures.
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A concise synthetic route for large‐scale manufacture of the hepatitis C virus (HCV) protease inhibitor BI 201335 has been developed. A convergent synthetic design was achieved by using three advanced intermediates: a densely functionalized thiazole‐quinoline, a hydroxyproline‐containing dipeptide acid, and an optically pure vinylcyclopropane. Only three subsequent synthetic steps were then required for the final assembly of this complex target. The first step is a critical CO bond formation to join the heterocycle and the peptidic portion of the molecule, which was done by using a newly‐designed heterocyclic sulfone. The second step uses an inexpensive peptide coupling of the aminocyclopropane and ester saponification, then recrystallization completes the route. This economical and practical process is suitable for large scale production of BI 201335, requires no protecting groups or chromatography, and every isolated intermediate is a crystalline solid.
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