in this paper, penetration of high velocity impact of 4340 steel and tungsten carbide projectiles with specific shapes in to ceramic armor that includes 10 mm alumina (95%) is considered analytically and simulated with ls-dyna software. bernoulli equation used to consider the penetration velocity in ceramics, shows that the penetration is better and easier by increasing projectile density. the ...

The decrease in particle size may offer new properties to drugs. In this study, we investigated the size reduction influence of the acetaminophen (C(8)H(9)O(2)N) particles by mechanical activation using a dry ball mill. The activated samples with the average size of 1 microm were then investigated in different time periods with the infrared (IR), inductively coupled plasma (ICP), atomic force m...

BACKGROUND At the end of fixed orthodontic treatment, the remnant of adhesive should be eliminated from the tooth surface. The purpose of this study was to compare the effect of three methods of removing adhesive on enamel surface roughness, dental pulp temperature, and also on the time spent. MATERIALS AND METHODS The brackets on 90 extracted teeth were debonded using bracket removal pliers....

Demands are increasing for micro axis-symmetric aspherical lenses to be installed in various optical devices. The micro glass lenses are generally molded by glass press process with micro aspheric ceramic molding dies or molds made of tungsten carbide or silicon carbide. These dies and molds are mostly ground with micro diamond wheels, but require additional finishing process as the size of the...

We report nanostructure electrodes for methanol electrooxidation by means of the co-sputtering deposition method. The Pt-WC-WO(3) three-phase electrode has higher I(f)/I(b) and oxidation current density i.e. improved electrocatalytic activity in comparison with those of pure Pt and two-phase electrodes because of both catalysis of tungsten carbide and size-control by tungsten oxide.

Tungsten trioxide microspheres of 2–4 m diameter have been prepared by controlled oxidation of tungsten carbide microspheres. These microspheres are characterized by XRD, SEM, and HRTEM. The microspheres are made of WO3 nanoparticles with an average diameter of around 15 nm. Platinum supported on these WO3 microspheres exhibits higher and stable electrocatalytic activity for methanol oxidation ...

Introduction The estimation of fish abundance by the echo-integrator method requires a sonar that has been accurately calibrated. This may be done by measuring the signal received from a target whose acoustic properties are known. Several kinds of metal spheres have been used as calibration targets, in particular brass (Forbes, Simmonds and Edwards, 19801, copper (Foote, et a/., 1981) and tungs...

An electron electric dipole moment search in the X"1 ground state of tungsten carbide molecules J. Lee, E.R. Meyer, R. Paudel, J.L. Bohn and A.E. Leanhardt* Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA; JILA, NIST and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA; Department of Physics, Wabash College, Crawfordsville, Indi...

The accuracy of compositional measurements using atom probe tomography is often reduced because some ions are not recorded when several ions hit the detector in close proximity to each other and within a very short time span. In some cases, for example in analysis of carbides, the multiple hits result in a preferential loss of certain elements, namely those elements that frequently field evapor...