Roger powder

Roger Powder. Blasting expl patented in Engl in 1870, contg 45% K chlorate plus materials... 

Platinum and palladium are the most common catalysts for alkene hydrogenations. Palladium is normally used as a very fine powder supported" on an inert material such as charcoal (Pd/C) to maximize surface area. Platinum is normally used as PtC, a reagent called Adams catalyst after its discoverer, Roger Adams. 

Gibson, N., D. J. Harper, and R. L. Rogers, "Hazards from Exothermic Decomposition of Powders," in Proceedings Runaway Chemical Reaction Hazards Symposium, IBC, London, England (1987). 

Skipping about two centuries, the activities of one experimenter typify the development of early black powder. His work took place between about 1235 and 1290 ad and he is reputed to have been the first scholar in Northern Europe who was skilled in the use of black powder. In essence, his work provided the backbone of all early chemical purification and formulation, without which the development of true gunpowders would not have been possible. His name was Roger Bacon (Figure 1.1). 

The wood is simply carbonised at relatively low temperatures in a restricted air supply to form an amorphous, quasi-graphitic carbon of very fine particle size. Although of reasonably high purity, it is the enormous surface area per unit mass of the charcoal which makes it very adsorbent to water vapour, and this property is conferred to the black powder mix, as Roger Bacon would have soon realised. 

In experimenting with fireworks, Roger Bacon and other medieval chemists discovered that a loose, open tray of powder was all that was needed to produce a flash, but in order to produce the bang the powder needed to be conhned, and this has great signihcance. And even with his unbalanced 6 5 5 formula. Bacon was able to deduce these fundamental ballistic effects. 

The noted English scientist Roger Bacon was quite familiar with potassium nitrate/charcoal/sulfur mixtures in the 13th century, and writings attributed to him give a formula for preparing "thunder and lightning" composition [5]. The use of black powder as a propellant for cannons was widespread in Europe by the 14 th century. 

A description of the composition and principles of the manufacture of black-powder appeared in the works of two of the greatest scientists of the Middle Ages Albertus Magnus (Saint Albert the Great), a Dominican Monk born in Bavarian Swabia near 1200, and Roger Bacon of the Franciscan Order, born, according tradition, about 1214 at Ilchester in Somerset, England. 

Mevalonic acid 5-pyrophosphate [1492-08-6] M 258,1, Purified by ion-exchange chromatography on Dowex-1 formate [Bloch et al. JBC 234 2595 7959], DEAE-cellulose [Skilletar and Kekwick, AB 20 171 7967], on by paper chromatography [Rogers et al. BJ99 381 7966]. Likely impurities are ATP and mevalonic acid phosphate. Stored as a dry powder or as a slightly alkaline (pH 7-9) soln at -20°. 

Preparation 1) E.R. Rogers et al, Coated Ultrafine Ammonium Perchlorate Particles , USP 3954526(1976) CA 85,96630(1976) [Claimed is the prepn of AP particles of sub-micron size for propints by soln in a mixt of two volatile liquids, the second being less volatile than the first, and a non-AP solvent. The first liq is evapd to form an AP suspension in the second. The AP is subsequently coated with surfactants or polymers which are partially soluble in the second solvent, and this solvent is evapd to yield a powder or slurry. The average coated AP particle is 0.52 to 0.99 microns in... 

The English scholar Roger Bacon has often been popularly credited as being the discoverer of black powder. That he knew of black powder and that it was composed of... 

Figure 17. Roger Bacon (c. 1214-1292). Probably the first man in Latin Europe to publish a description of black powder. He was acquainted with rockets and firecrackers, but not with guns.

A description in cypher of the composition of black powder in the treatise De nullitate magiae 12 which is ascribed to Roger Bacon has attracted considerable attention. Whether Bacon wrote the treatise or not, it is certain at any rate that the treatise dates from about his time and certain, too, that much of the material which it contains is to be found in the Opus Majus. The author describes many of the wonders of nature, mechanical, optical, medicinal, etc., among them incendiary compositions and firecrackers. 

Although Roger Bacon was not acquainted with guns or with the use of black powder for accomplishing mechanical work, yet he seems to have recognized the possibilities in the mixture, for the treatise On the Nullity of Magic comes to an end with the statement Whoever will rewrite this will have a key which opens and no man shuts, and when he will shut, no man opens. 18... 

This time, it was the 1980s epidemic fueled by crack. In 1986, the death of two promising young athletes, Len Bias and Don Rogers, added to public outrage. The new laws differentiated between powder cocaine and crack and were much harsher on the latter. These laws require 100 times as much powder cocaine possession as crack to trigger an identical minimum mandatory prison sentence. Ongoing controversy surrounds this law. Several bills have been introduced to reduce the disparity, but none have been passed into law as of early 2002. 

A mixture known as black powder revolutionized the art of warfare whenever it was applied to the propulsion of missiles. Black powder is a mixture of potassium nitrate (saltpeter), charcoal, and sulfur in varying proportions, granulation, and purity. A typical composition of a modern black powder is saltpeter 75%, charcoal 15%, and sulfur 10%.7 A mixture of saltpeter, charcoal, and sulfur with other ingredients was used in China and India in the eleventh century for incendiary and pyrotechnic purposes long before true black powder was invented.8 History often deals in conjecture and opinion and it is not known for certain when and by whom black powder was invented, or when and by whom it was applied to the propulsion of a missile from a firearm. The composition of black powder was first recorded by English Franciscan monk Roger Bacon in 1249, but he did not apply it to the propulsion of a missile from a firearm. This use of black powder is usually credited to a German Franciscan monk Berthold Schwartz in the early fourteenth century.9... 

The first known explosive material was black powder, a mixture of potassium nitrate (saltpeter), charcoal, and sulfur. As such it is a composite explosive whose properties are dependent upon how finely divided each of the ingredients is, and how intimately they are mixed. The exact origins of black powder are lost in antiquity. Publications referring to it seem about equally divided between those that attribute its origin to third- or fourth-century China7,8 and those that place it closer to the 13th century, at about the time of Roger Bacon s written description in 1242.9-13 Nevertheless, its use did not become very popular until the invention of the gun by... 

Curry, C. J., Rendle, D. F. and Rogers, A. (1982). Pigment analysis in the forensic examination of paints. I. Pigment analysis by x-ray powder diffraction. J. Forensic Set, 22, 173-7. [260t, 26It]... 

Rogers, T.L. Johnston, K.P. Williams, R.O. 3rd Solution-based particle formation of pharmaceutical powders by supercritical or compressed fluid CO2 and cryogenic spray-freezing technologies. Drug Dev. Ind. Pharm. 2001, 27 (10), 1003-1015. 

Rogers, T.L. Overhoff, K.A. Shah, P. Santiago, P. Yaca-man, M.J. Johnston, K.P. Williams I., Robert O. Micro-nized powders of a poorly water soluble drug produced by a spray-freezing into liquid-emulsion process. Eur. J. Pharm. Biopharm. 2003, 55 (2),... 

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