Military Academy

About: Military Academy is a based out in . It is known for research contribution in the topics: Population & Fuzzy logic. The organization has 2478 authors who have published 3003 publications receiving 33188 citations.

Discrimination and identification of plastic landmine casings by single-shot broadband LIBS

Abstract: Laser-induced breakdown spectroscopy (LIBS) spectra were collected under laboratory conditions and compiled in a library for a suite of plastic landmine casings and a variety of non-mine plastic materials on two occasions during 2004 using a Nd-YAG laser and a high-resolution broadband spectrometer to collect the full 200-980 nm LIBS spectrum.. The landmine casings examined included a broad selection of anti-personnel and anti-tank mines from different countries of manufacture. Two 'blind' tests were conducted in which LIBS spectra for the landmine casings and plastics were compared with a previously-constructed material spectral library. Using a linear correlation software, 'mine/no mine' determinations were correctly made for >90% of the samples in both tests.

A novel algorithm for high sensitivity in measuring surface variation based on volume holography

Abstract: A novel design for the precise measurement of surface variation based on volume holography is proposed. The volume hologram is a spatial filter, which records the index grating corresponding to the interference fringes by a plane wave and a divergent spherical wave. In the measuring process, a point source attached to a probe is used to read the hologram. A precise measurement can be achieved because the horizontal displacement of the point source is very sensitive to the hologram. This sensitivity is higher than that of a holographic confocal microscopy based on the longitudinal displacement. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 319–321, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10448

Experimental and Simulation Testing of Flight Spin Stability for Small Caliber Cannon Projectile

Abstract: The basic aim of this paper is to consider correlations of stability flight criteria, derived as the relations of aerodynamic coefficients and derivatives, on the model of small caliber cannon spin stabilized projectile. Model of stability criteria calculations are performed by experimentally testing of aerodynamic data in the wind tunnel, and composed with the semi-empirical data, both applied on the flight trajectory stability simulation test. Authors’ wind tunnel tests and calculated values of aerodynamic coefficients, as function of Mach numbers of projectile model are presented in the simulation flight trajectories stability criteria. The comparative analysis of experimental and calculated aerodynamic coefficients of projectile model is done, refers to the stability flight criteria. Calculation of projectile aerodynamic Magnus moment derivatives, with other aerodynamic representatives, is used as the critical stability factors testing data vs. flight Mach numbers. Influences of this derivative absence and presence on the model sequence of the flight trajectory are presented for the estimation of angles of attack damping and stability factors. Simulation tests are presented for the supersonic and subsonic integral flight velocities and spin damping data. Research is realized due to the considerations of further projectiles correction possibilities on trajectory, and other new applications, vs. existing of unreliable lateral moments.

The observation of dislocation reversal in front of crack tips of polycrystalline copper after reducing maximum load

Abstract: The loading at a crack tip varies during fatigue crack propagation. As a result, overloading causes retardation of crack propagation, and underloading causes the acceleration of crack propagation. In addition, reducing the load range by changing either the minimum load or maximum load can cause a reduction or retardation of crack propagation to occur. Examining a fatigue cracked specimen made of polycrystalline copper with back scattered electron images (BEI) in a scanning electron microscope (SEM) revealed that (1) the dislocation structures close to the crack tips gradually evolved from a cell structure into a new loop patch structure during the crack retardation period which follows after reducing the maximum load; (2) restoring the crack propagation rate is a result of re-establishing the cell structure from new loop patches or PSBs; and (3) the evolution of the dislocation structure at the crack tip due to the maximum loading reduction is affected by residual active slip systems.