Engineering test procedure for the patient assist device

The test procedure completely tests the functioning of the patient assist device. All modes of operation are included in the test. Patient activated switches may be chosen for use with this device as desired. These switches, however, must be single-pole, single-throw, momentarily-on switches

Creep at elevated temperatures and high vacuum Semiannual report no. 3, May 1 - Oct. 31, 1965

Creep tests on polycrystalline copper with surface reoxidized or cleaned by argon bombardment at elevated temperatures and high vacuu

Four-loop pressure of massless O(N) scalar field theory

Inspired by the corresponding problem in QCD, we determine the pressure of massless O(N) scalar field theory up to order g^6 in the weak-coupling expansion, where g^2 denotes the quartic coupling constant. This necessitates the computation of all 4-loop vacuum graphs at a finite temperature: by making use of methods developed by Arnold and Zhai at 3-loop level, we demonstrate that this task is manageable at least if one restricts to computing the logarithmic terms analytically, while handling the ``constant'' 4-loop contributions numerically. We also inspect the numerical convergence of the weak-coupling expansion after the inclusion of the new terms. Finally, we point out that while the present computation introduces strategies that should be helpful for the full 4-loop computation on the QCD-side, it also highlights the need to develop novel computational techniques, in order to be able to complete this formidable task in a systematic fashion.Comment: 34 page

Non-perturbative plaquette in 3d pure SU(3)

We present a determination of the elementary plaquette and, after the subsequent ultraviolet subtractions, of the finite part of the gluon condensate, in lattice regularization in three-dimensional pure SU(3) gauge theory. Through a change of regularization scheme to MSbar and a matching back to full four-dimensional QCD, this result determines the first non-perturbative contribution in the weak-coupling expansion of hot QCD pressure.Comment: 6 pages, 4 figures, talk presented at Lattice 2005 (Non-zero temperature and density

Impact instrument

An impact instrument for delivering an impulse to an object. The impact instrument may include an impact surface for contacting the object and an elongated member extending from the impact surface that terminates in an end. The elongated member may include a grasping region in the vicinity of the end. When the instrument is grasped within the grasping region, the center of percussion of the instrument preferably coincides with the impact surface. The instrument may also contain a pivoting grasping member disposed on the elongated member. A cavity is preferably formed between the grasping member and the elongated member and may contain compressible material. The grasping member may rigidly contact the elongated member at an ideal pivot point. The grasping member is preferably adapted to pivot with respect to the elongated member at the ideal pivot point. The pivoting of the grasping member preferably increases the amount of impulse delivered to an object, decreases vibration experienced by the user of the instrument, and reduces counter-rotational forces imparted from the instrument to the user. The impact instrument may be a hammer, ax, golf club, tennis racket, or similar device.Board of Regents, University of Texas Syste

Diffusion-emission theory of photon enhanced thermionic emission solar energy harvesters

Numerical and semi-analytical models are presented for photon-enhanced-thermionic-emission (PETE) devices. The models take diffusion of electrons, inhomogeneous photogeneration, and bulk and surface recombination into account. The efficiencies of PETE devices with silicon cathodes are calculated. Our model predicts significantly different electron affinity and temperature dependence for the device than the earlier model based on a rate-equation description of the cathode. We show that surface recombination can reduce the efficiency below 10% at the cathode temperature of 800 K and the concentration of 1000 suns, but operating the device at high injection levels can increase the efficiency to 15%.Comment: 5 pages, 4 figure