Gunpowder Explosion Research Articles

Comparison of air driven and gun powder driven microprojectiles in gene transfer system

The successful delivery of foreign material into plant tissues using gun powder driven microprojectile-mediated gene transfer system has been reported. In the gun powder driven microprojectile-mediated gene transfer system, the tungsten microprojectiles coated with the foreign genetic material is accelerated by an explosion of gun powder (Fig.1). The main disadvantages of the gun powder driven microprojectile are: variability of the velocity of the spent gas which can cause cell damage and random frequency of transformation, and the build up of unburned gun powder in the apparatus which can causeor create safety problems. An improved microprojectile for use in the genetic engineering ofplants which involves the use of air or gas pressure from a conventional pressurized air or gas supply as the accelerator has been developed. (Fig. 2). A comparison of the air driven and gun powder driven microprojectile is illustrated in electon micrographs of plant tissues bombarded by both methods (Figs. 5-8).

Gunpowder and the Chemical Revolution

T HE CHEMICAL STUDY OF GUNPOWDER DETONATION in the early nineteenth century has its antecedents in discussions of gunpowder explosion, or of niter, throughout the eighteenth century. This hitherto neglected topic illuminates significant aspects of the Chemical Revolution, including the development of the concept of the gaseous state in the eighteenth century and the development of Lavoisier's thermochemistry. This article is divided into two parts. The first examines the discourse over detonation in the time leading up to the Chemical Revolution. Here I argue that detonation attracted much attention to the subject of possible states of matter and their change through chemical reaction because detonation was a most striking manifestation of the release of an air or some other enormously expansible material from a solid. I shall outline what I see as three traditions of explanation for gunpowder detonation current by the mid-eighteenth century: the aerial, the vaporous, and the aqueous explanations. The second part explores the study of and theorizing about detonation during the 1770s and 1780s. Here I examine the role played by the study of detonation in the development of Antoine-Laurent Lavoisier's thermochemical theory and its interaction with the phlogiston theory as upheld by Claude-Louis Berthollet, the chemist who was in fact to become Lavoisier's first major convert. My focus is exclusively on the filiation of scientific ideas before and during the Chemical Revolution. I recognize that there is another, complementary aspect of this subject-that of the context of these ideas in the industrial and military history of gunpowder manufacture, quality control, and testing in the eighteenth century. This aspect, too, has remained virtually unexplored by scholars; how it bears on the scientific ideas and debates I investigate here remains to be explored.

A Technique for the Removal of Gunpowder Tattoos

The explosion of gunpowder in proximity to exposed skin surfaces can result in the ingraining of numerous pigmented particles in the dermis. The cosmetic defect of such tattooing, if extensive, can be great. Similar particulate matter embedded in the skin following abrasive contact of skin areas with hard, dirty surfaces can be removed by brushing the anesthetized wound with a stiff brush. However, gunpowder tattooing, because of its depth in and intimate adherence to the dermis, can be completely resistant to such brushing, as well as to other direct methods of removal. In the course of treating a case of extensive gunpowder tattooing of the face, a technique for removal of the embedded particles was evolved. This technique facilitated the removal of more than 600 separate conglomerations of pigmented matter from the forehead, eyelids, nose, cheeks, and ears in a reasonable period of time, with virtually no residual scarring. Because

The Experiment of Break-down of Snow Cornice by Gun-Powder Explosion

One of the methods to prevent an avalanche is to break down snow cornice and unstable snow cover on a slope. We made an experiment to break down snow cornice and snow-cover by gun-powder.The relation between snow structure, the amount of gun-powder and the size of destruction hole was obtained. A good result was also obtained on the method of effective explosion.

Wartime experience with skull injury and blast and their effect upon the ear.

<h3>I. HISTORICAL DATA</h3> MILITARY acoustic trauma caused by gunpowder explosions has probably been with us since 1353 A. D., when Typsiles of Augsburg introduced gunpowder to Germany, thus inaugurating its use by the people of western Europe.¹Several centuries were to elapse, however, before efficiently operating explosive weapons completely replaced the battering ram, the long bow, and the sword. In 1886, one who signed himself "Volunteer" brought the problem to the attention of the readers of the<i>Lancet</i>. He asked, "Can any of your readers suggest a remedy for deafness caused by rifle shooting?" The answer, presented by John Chippendale in a later issue, was, "Allow me to suggest the wearing of cotton in the ears while at rifle practice. This is done in France, at any rate, by artillerists to prevent deafness and bleeding of the ears."² A volunteer of a more recent date has testified to the perseverance of

Case of Keratitis following Gunpowder Explosion

Case of Keratitis following Gunpowder Explosion

I. Fired gunpowder. Note on the existence of potassium hyposulphite in the solid residue of fired gunpowder

In our second memoir on fired gunpowder we have discussed in detail that part of M. Berthelot’s friendly criticism of our first memoir which relates to the potassium hyposulphite found by us, in variable proportions, in our analyses of the solid products obtained by the explosion of gunpowder in the manner described. While pointing out that we had taken every precaution in our power to guard against the production of hyposulphite, by atmospheric action upon the potassium sulphide, during the removal of the hard masses of solid products from the explosion vessel, and had effectually excluded air from them, when once they were removed until they were submitted to analysis, we admitted the impossibility of guarding against the accidental formation of some hyposulphite during the process of removal, especially in some instances in which the structure of the residue had certainly been favourable to atmospheric action, and in which a more or less considerable development of heat had afforded indications of the occurrence of oxidation. We contended, however, that the method of analysis, and the precautions adopted by us in carrying it out, precluded the possibility of accidental formation of hyposulphite at this stage of our investigations. With respect to the precautions, we could, and still do, speak with perfect confidence; and we certainly have believed ourselves fully justified in being equally confident with respect to the process adopted by us for the determination of the proportions of sulphide and hyposulphite, inasmuch as we accepted and used in its integrity the method published in 1857 by Bunsen and Schischkoff in their classical memoir on the products of explosion of gunpowder, and adopted since that time by several other investigators who have made the explosion of gunpowder the subject of study, and whose results are referred to in our first memoir.

IX. Researches on explosives.—fired gunpowder

After an historical review of the investigations and theoretical views relating to the results produced upon the explosion of gunpowder, which have been published during the last 150 years, the authors proceed to describe the chief objects contemplated by their researches, which are in continuation of some commenced by Captain Noble in 1868, and described in a lecture delivered at the Royal Institution in 1871.

The great explosion of gunpowder; and the breach in the river embankment

The great explosion of gunpowder; and the breach in the river embankment

XV.—Account of recent researches on the application of electricity, from different sources, to the explosion of gunpowder

XV.—Account of recent researches on the application of electricity, from different sources, to the explosion of gunpowder

On the electro-magnetic properties of metalliferous veins in the mines of cornwall

The author having been led from theory to entertain the belief that a connexion existed between electric action in the interior of the earth, and the arrangement of metalliferous veins, and also the progressive increase of temperature in the strata of the earth as we descend from the surface, proceeded to the verification of this opinion by experiment. His first trial was unsuccessful; but in the second he obtained decisive evidence of considerable electrical action in the mine of Huel Jewel in Cornwall. His apparatus consisted of small plates of sheet copper, which were fixed in contact with one in the veins by copper nails, or else wedged closely against them with wood­en props stretched across the galleries. Between two of these plates at different stations, a communication was made by means of copper wire one twentieth of an inch in diameter, which included a gal­vanometer in its circuit. In some instances, 300 fathoms of copper wire were employed. The intensity of the electric currents was found to differ consider­ably in different places; it was generally greater in proportion to the greater abundance of copper ore in the veins, and in some de­gree also to the depth of the stations. Hence the discovery of the author seems likely to be of practical utility to the miner in discover­ing the relative quantity of ore in veins, and the directions in which it most abounds. The electricity thus perpetually in action in mines does not appear to be influenced by the presence of the workmen and candles, or even by the explosion of gunpowder in blasting.

Danger from the premature explosion of gunpowder in the blasting of rocks, with suggestions as to the means of prevention

Danger from the premature explosion of gunpowder in the blasting of rocks, with suggestions as to the means of prevention

XII. Experiments to determine the force of fired gunpowder

No human invention of which we have any authentic records, except, perhaps, the art of printing, has produced such important changes in civil society as the invention of gunpowder. Yet, notwithstanding the uses to which this wonderful agent is applied are so extensive, and though its operations are as surprising as they are important, it seems not to have hitherto been examined with that care and perseverance which it deserves. The explosion of gunpowder is certainly one of the most surprising phænomena we are acquainted with, and I am persuaded it would much oftener have been the subject of the investigations of speculative philosophers, as well as of professional men, in this age of inquiry, were it not for the danger attending the experiments: but the force of gunpowder is so great, and its effects so sudden and so terrible, that, notwithstanding all the precautions possible, there is ever a considerable degree of danger attending the management of it, as I have more than once found to my cost. Several eminent philosophers and mathematicians, it is true, have, from time to time, employed their attention upon this curious subject; and the modern improvements in chemistry have given us a considerable insight into the cause, and the nature of the explosion which takes place in the inflammation of gunpowder; and the nature and properties of the elastic fluids generated in its combustion. But the great desideratum, the real measure of the initial expansive force of inflamed gunpowder, so far from being known, has hitherto been rather guessed at than determined; and no argument can be more convincing to show our total ignorance upon that subject, than the difference in the opinions of the greatest mathematicians of the age, who have undertaken its investigation.