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Ultrasound irradiation is used for anchoring silver nanoparticles with an average size of 51 nm onto the surface of poly(methyl methacrylate) PMMA chips (2 mm diameter), and silver nanoparticles with an average size of 20 nm onto the surface of the PMMA spheres (1-10 mm). The sonochemical reduction was carried out under argon atmosphere at room temperature. The silver nanoparticles were obtained by the irradiation of a mixture containing the PMMA, silver nitrate, ethylene glycol, ethanol, water, and 24% (wt) aqueous ammonia for 2 h, yielding a PMMAnanosilver composite. By controlling the atmosphere and reaction conditions, we could achieve the deposition of silver nanoparticles onto the surface of poly(methyl methacrylate). The silver-deposited PMMA chips (loaded with 0.01-1.0 weight percent silver) were successfully homogenized in melt by extrusion and then injection molded into small, discshaped samples. These samples were analyzed with respect to their directional spectral optical properties in UV, VIS, and IR spectroscopy.

The thermal conductivity K of pure He 3 and of two dilute solutions of He 3 in He 4 has been measured from 30 down to 5 mdeg K or below. For pure He 3 , KT increases with increasing temperature. For the dilute solutions at low enough temperatures, K is consistent with the T~i temperature dependence of a normal Fermi liquid, but the magnitudes of KT do not agree with values computed from an effective potential based on spin-diffusion coefficient measurements.We have measured at saturated vapor pressure the thermal conductivity both of pure liquid He 3 and of the same two dilute solutions of He 3 in He 4 for which measurements of specific heat, spin-diffusion coefficient, and magnetic susceptibility have already been reported. 1 The results relate to the question of the anomalous behavior of pure He 3 at low temperatures 2 ' 3 and to the effective interactions between He 3 quasiparticles in the dilute solutions. 4

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