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Analytical solutions for the quasi-static and low-velocity perforation of sandwich panels with woven roving E-glass/vinyl ester facesheets and Coremat were derived. A multi-stage perforation process involving delamination, debonding, core shear fracture and facesheet fracture was used to predict the quasi-static failure load and ballistic resistance of the panel. The high core-crushing resistance and damping of the Coremat resulted in rupture of the distal facesheet before the incident facesheet during panel perforation because they limited the amount of local indentation compared with global panel deformation. Analytical predictions of the quasi-static load-deflection response and the dynamic contact force history were within 10% of the test results. [ABSTRACT FROM AUTHOR]

This study evaluates the energy absorption, perforation and damage evolution created by cylindrical projectile of different nose geometries in woven roving mat/epoxy laminates with 0.45° orientation. A series of ballistic impact tests have been carried out on the laminate with projectile nose geometries representing hemispherical, conical, and conical with round nose and truncated tip. A gas gun projectile launcher set-up was employed to impact the target at different speeds. The damage pattern, perforation mechanism and ballistic limit for each type of projectiles have been studied. Truncated-nose projectile shows the highest ballistic limit while sharp-nose shows the lowest. A quasi-static punch test was carried out on targets with projectiles of above-mentioned nose geometries to assess the damage evolution at a constant strain rate. The maximum load required to cause perforation during punch test was noted for hemispherical-nose projectile. An in-depth layerwise analysis was carried out to analyse the damage in each layer. [ABSTRACT FROM AUTHOR]

Polycarbonate is commonly used as the material of riot shields. Firings of 83 g steel ball bearings at velocities of 23–98 ms–1 produced damage in the form of dents. Subsequent tensile testing showed a small drop in yield strength and ductility for impact velocities greater than 58 ms–1. This drop in yield strength and ductility was more marked for specimens that had been soaked in acetone for 10 min after ballistic impact. Soaking in n-heptane produced no similar effect to that seen with acetone. Measurements were taken of the velocities of projectiles likely to be thrown by rioters. These showed that the measured velocities were lower than those that caused macroscopic damage to polycarbonate when hit by a ball bearing. Thus susceptibility to brittle failure is likely to be associated with shields that have been hit by sharp objects and exposed to solvents after impact. Mechanical stressing of polycarbonate at the point of impact by the ball bearing had no effect on the subsequent mechanical properties. This is in contrast to the embrittlement seen in polycarbonate when internal strains are present produced on fast cooling from the melt. [ABSTRACT FROM AUTHOR]

The article describes a property of ellipses which was observed by the physicist Jean-Marc Richard in connection with a problem from ballistics. The maximal perimeter of a parallelogram inscribed in a given ellipse can be realized by a parallelogram with one vertex at any prescribed point of the ellipse. The well-known geometric object to which the foregoing discussion relates is the orthoptic circle of Monge, who proved that the locus of points from which one sees an ellipse at right angles is a circle.

Forensic science can be a powerful tool in counter-terrorism, not only in post-incident prosecution, but also in pre-incident deterrence. Examples are given from experience in Israel, and the question is raised how professionals can be taught to maximize upon the capabilities of forensic science. [ABSTRACT FROM AUTHOR]

A new analytical impact/penetration model has been developed for high-velocity impact of thick composite targets using a spring-mass equivalent energy dissipating finite element/finite difference scheme. The initial basic model includes energy dissipating mechanisms such as punching shear and fiber breakage. The impact/penetration law, which is based on a linear distribution of punching shear force, is represented by a stiffness parameter. The equivalent variable mass of the composite target is built into the model by considering two-dimensional shear wave propagation, and its effective stiffness was initially represented by a nonlinear spring stiffness that is obtained from analyzing an infinite hollow cylinder subjected to internal in-plane shear. The two stiffness parameters are characterized by analyzing the forces between the impactor and the composite target at increasing depths of penetration through a series of quasi-static finite element analyses. Results are used to provide a more accurate prediction if the impactor would perforate or stop, and to obtain an estimate of its exit velocity or the depth of penetration for both blunt-ended and sharp-ended impactors penetrating a thick composite target at high speed. Analyses were performed to demonstrate different high-velocity impact scenarios. [ABSTRACT FROM AUTHOR]

The development of lightweight armour systems for ballistic protection is under continuing attention of the manufacturers and users. A new design of the composite armour systems has been developed and ballistically tested. A new armour system consists of a ceramic plate, an intermediate ceramic–polymer layer and a polymer fibre lining as a backing material. The proposed composite armour systems prepared with a use of specially selected compositions of the intermediate layer promoting the absorption of the kinetic energy of projectiles provide adequate ballistic protection to National Institute of Justice (NIJ) level III and level IV, and they successfully withstand multiple hits. [ABSTRACT FROM AUTHOR]

We investigate the influence of molecular motion on DNA conductance and charge transfer in the ballistic transport regime. We evaluate the conductance/charge transfer properties for ensembles of conformations representative of the molecular fluctuations in an explicit all-atom representation. We generate such ensembles by classical molecular dynamics (MD) and investigate the influence of conformational change on the charge transfer properties of the system. Using this approach, we can qualitatively explain the influence of base-pair mismatches on DNA electrical properties. [ABSTRACT FROM AUTHOR]

A computational approach for the engineering analysis of ablative-type thermal protection systems (TPS) in atmospheric reentry ballistic flights is communicated. We first propose an improved lumped differential approach for ablative thermal protection analysis, which involves the use of materials with low thermal diffusivity. The results obtained for a one-dimensional thermal ablation problem in a finite slab are compared against those obtained by previously reported lumped differential solutions. Benchmark results for the local nonlinear model, obtained through the generalized integral transform technique, are utilized to verify the proposed solution in a realistic ablation problem, consisting of a low thermal diffusivity material subjected to a prescribed net aerodynamic heating. In addition, an integrated symbolic–numerical system is constructed based on the Mathematica platform for the derivation and computation of all the related quantities along the flight, yielding the transient behavior of the TPS recession and thermal performance for both the constant and variable initial thickness along the vehicle nose region. An illustrative example of the computational tool and the typical results for an orbital platform in ballistic reentry flight are presented. [ABSTRACT FROM AUTHOR]

We present ab initio calculations for spin injection in Fe-ZnSe and Fe-GaAs(001) systems, with and without detection by a second Fe lead. We consider the case of hot injection, as well as the presence of a tunneling barrier at the interface. Our calculations are valid in the ballistic regime. We find that these systems can be very efficient spin filters, leading to current spin polarizations and magnetoresistance ratios very close to the ideal 100%. [ABSTRACT FROM AUTHOR]

Discusses the controversy over the nuclear weapons program of Iran, as of 2002. Details on its policy of nuclear and missile technology procurement from China, Russia and North Korea; Significance of the nuclear infrastructure in Iran; Background on the ballistic missile program of Iran.

Focuses on the role of mathematician and United States Army officer Oswald Veblen in bringing mathematics into the First World War. How academic mathematicians reacted to army life; Overview of the mathematical ballistics of 1918; Details on the application of mathematical ballistics in the army.

Discusses ballistics and ballistic trajectory, the use of geometry on parabola and its application on the science of motion. Overview of the Galilean model; Details on the resisted shot; Information on enveloping parabolas; Details on the mechanics.

Focuses on the theory of Evangelista Torricelli on ballistics. Invention of Torricelli on measuring instruments; Contributions of Torricelli on astronomy; Views of Torricelli on the application of mathematics in physics.

An introduction is given to the methods of production and the properties of one-, two-, and three-dimensional electron gases. In two dimensions this includes the formation of electron solids (Wigner crystallization) and the quantum Hall effects and in one-dimension, the quantization of ballistic transport. The article ends with a short discussion of the applications of low-dimensional structures in electronic and optoelectronic systems. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the feeding behaviour in the cassowary or Casuarius casuarius that exploits fallen fruits. The study uses plesiomorphic tetrapod pattern and calculates kinematics of movement of the elements during food transport. Result reveal that transported food follows a ballistic curve with energy passed on by head backward displacement, permitting it to reach pharynx. It adds that the mechanism could be viewed as a specialisation or an ancestral mechanism.

An introduction is presented in which the editor discusses topics published in the journal including ballistics, analysis of the effectiveness of historic firearms, and conflict archaeology.

The article presents a study which defines a method used for evaluating the injury potential of less lethal projectiles on the thoracic region. The study uses accelerometers and pressure sensors to measure the skeletal dynamic deflection and the distribution of thoracic response in porcine models. Result shows that kinetic energy is not sufficient for the local skeletal response to the impact of two projectiles.

The article reports on the session on the history of mathematics, held by the Canadian Mathematical Society in Calgary, Alberta from June 3 to 4, 2006. Head speaker Tom Archibald discussed Emile Picard's work on the history of mathematics. Some of the topics discussed include the origins of Mittag-Leffler Theorem and history of ballistics.

Provides information on the use of the science of ballistics in the fictional works of author Edgar Allan Poe. Use of ballistic evidence in a detective tale from the periodical 'Godey's Lady's Book'; Expertise of Poe in criminology.