We report on the thermal conductivities of microcrystalline [6,6]-phenyl C(61)-butyric acid methyl ester (PCBM) thin films from 135 to 387 K as measured by time domain thermoreflectance. Thermal conductivities are independent of temperature above 180 K and less than 0.030 ± 0.003 W m(-1) K(-1) at room temperature. The longitudinal sound speed is determined via picosecond acoustics and is found ...

| In a note at the end of his paper Recherches sur les fractions continues, Stieltjes gave a necessary and suucient condition when a continued fraction is represented by a meromorphic function. This result is related to the study of compact Jacobi matrices. We indicate how this notion was developped and used since Stieltjes, with special attention to the results by M. G. Krein. We also pay atte...

In locally compact spaces, (Borel-)measurable sets can be approximated by compact sets. Ulam extended this result to complete separable metric spaces. We give a constructive proof of Ulam’s theorem. It is first proved intuitionistically and then, using a logical ‘trick’ due to Ishihara, a proof acceptable in Bishop-style mathematics is obtained. We feel this proof provides some insight into Ish...

In 1981, the US dairy industry experienced a major change in federal policy. From 1950 until 1981 farm level milk prices were supported at a minimum of 75 to 90 percent of parity. Under parity the support price and farm level milk prices trended upward most years. But in 1981, support prices were de-coupled from the parity index. Instead, the support price would be based on the level of milk su...

Introduction Powder metallurgy (p/M) is a rapidly expanding technology for manufacturing of structural parts. The PA4 process provides economical as well as technical benefits over conventional processing of wrought material. It is possible to fabricate high quality, complex parts to close tolerances without machining. The energy consumption is low and the material utilisation and productivity ...

The usage of powder metallurgy aluminium compacts in lieu of ferrous components in automotives helps to lower vehicle weight. The major drawback in the commercially available press sintered aluminium alloy is porosity which is mainly dependent on the powder metallurgical process parameters such as compaction pressure, sintering temperature and cooling rate after sintering. In this paper the eff...