To facilitate urine sample preparation prior to head-space gas-chromatographic (HS-GC) analysis. Urine samples containing one of the five solvents (acetone, methanol, methyl ethyl ketone, methyl isobutyl ketone and toluene) at the levels of biological exposure limits were aspirated into a vacuum tube via holder, a device commercially available for venous blood collection (the vacuum tube method...

An evacuated tubular solar collector was fabricated from acrylics for improved resistance to shattering. A plasmatron was employed to apply a thin gas-barrier coating to the surfaces of the plastic tube to prevent/alleviate gas infiltration. Experiments were conducted to investigate the effect of vacuum level on the performance of the non-glass vacuum-tube solar collector. Inserted in the evacu...

Dielectric material between capacitor electrodes increases the capacitance. However, when the electric field exceeds a threshold, electric breakdown in the dielectric discharges the capacitor suddenly and the stored energy is lost. We show that nano vacuum tubes do not have this problem because (i) electric breakdown can be suppressed with quantization phenomena, and (ii) the capacitance is lar...

The tachyon effective field theory describing the dynamics of a non-BPS D-p-brane has electric flux tube solutions where the electric field is at its critical value and the tachyon is at its vacuum. It has been suggested that these solutions have the interpretation of fundamental strings. We show that in order that an electric flux tube can ‘end’ on a kink solution representing a BPS D-(p− 1)-b...

Wunderlich, Kaufman, and Smith 2 routing after a finite and usually small number of iterations. An empirical case study based on the roadway network in Troy, Michigan is included. * This research was supported in part by the University of Michigan ITS Research Center of Excellen Wunderlich, Kaufman, and Smith