Abstract Recoil reduction is one of the most important issues for design aircraft gun. Traditional approaches this purpose will produce back-blast, which constitutes a hazard to fighter planes or attack helicopters. This paper presents closed type gas reflection device gun aiming reduce recoil force without ejecting propellant rearward. The launching process modeled by coupling classical interi...

The production f magnetic fields by hypervelocity meteoroid mpact has been proposed toexplain the presence of palcomagnetic fields in some lunar samples a well as on the lunar surface. Impact-generated magnetic fields also may be significant for the palcomagnetic re ord on a variety of cratered surfaces inthe solar system, such as the Moon, Mercury, Phobos, and asteroids. Previous experiments w...

The present study attempted to investigate the emergence of especial skill in shooting with air gun at two skill levels (skilled, novice). The population studied here included all male and female shooters from the city of Semnan. The study was conducted on a sample of 40 shooters, consisting of two groups of women with the mean age of 21.33±2.26 and two groups of men with the mean age of...

A two-stage 500 kV 200-A ferroelectric electron gun has been designed, fabricated, tested, and used in a high power microwave amplifier experiment. We report on the operational characteristics of the gun including measurements of the beam dynamics. The optimum conditions for application of the trigger and its timing are also reported. Faraday cup measurement shows that the beam radius is 4.1 mm...

The present study was conducted to identify nutritional value of Rumex obtusifolius in three phenological stages (vegetative growth, flowering, and maturity). Samples were randomly taken in pastures of Saravan in Rasht, Iran in 2015. After drying and grinding, the chemical compositions of Crude Protein (CP), Crude Fiber (CF), Ether Extract (EE), Total Ash (ASH), Neutral Detergent Fiber (NDF), a...

Friction ridge detail was enhanced on f ired and unfired 9 mm brass Luger ammunition casings using three techniques, two involving gun blue reagent at a concentration of 50% v/v. Fingermarks were deposited on 90 ammunition casings, and half were discharged using a Glock 19 semiautomatic pistol. Mark development was achieved using either superglue fuming followed by basic yellow 40 f luorescent ...

BACKGROUND Among developed nations, the United States has the highest rate of civilian gun ownership, and the highest homicide rate. We examine whether the United States is merely an exception, or if a relationship between gun availability and homicide exists across all developed nations. METHODS Homicide rates for the early 1990s come from 26 of 27 of the highly industrialized or high-income...