Bleaching of polymeric materials can be achieved by blending or surface treatment with fluorescent brighteners, FBs [1]. In both cases the FB migrates with time, and the degree of whiteness decreases. The introduction of polymerizable groups into the FB makes it applicable in the copolymerization process with vinyl monomers, resulting in the formation of covalent bonds in the polymer molecule. ...

Motivated by a recent study by Lazarian and Draine, which showed that a high degree of grain alignment of the paramagnetic dust is achievable if the rates of internal relaxation are controlled by the Barnett relaxation process, we undertake a study of an alternative mechanism of internal dissipation, namely, the inelastic dissipation of energy in oblate dust grains. We find that deformations at...

Motivated by a recent study by Lazarian and Draine, which showed that a high degree of grain alignment of the paramagnetic dust is achievable if the rates of internal relaxation are controlled by the Barnett relaxation process, we undertake a study of an alternative mechanism of internal dissipation, namely, the inelastic dissipation of energy in oblate dust grains. We find that deformations at...

This study investigates the influence of some chemical additives such as methanol, ethanol, sodium oleat, chloroform and sodium hexametaphosphate (SHMP) on the dry fine grinding of calcite (X50= 33 µm) using a stirred media mill. The experiments were carried out by a batch operation, and the change in colour properties (Ry, whiteness and yellowness) of calcite powder. The results showed that th...

Composition of the Comet dust obtained by the dust impact analyzer on the Halley probes indicated that the comet dust is a mixture of silicate and carbonaceous material. The collected interplanetary dust particles (IDP’s) are fluffy and composite, having grains of several different types stuck together. Using Discrete Dipole Approximation (DDA) we study the scattering properties of composite gr...

Broadband wireless channels, where high data rates are transmitted, are extremely dispersive in nature. A fundamental challenge in the design of equalizers for the broadband case lies in reducing complexity. Broadband finite impulse response (FIR) beamformers employ a space-time antenna array which reduces the multipath delay spread to narrowband levels. The beamformers should additionally pres...