Special treatment reduces helium permeation of glass in vacuum systems

Internal surfaces of the glass component of a vacuum system are exposed to cesium in gaseous form to reduce helium permeation. The cesium gas is derived from decomposition of cesium nitrate through heating. Several minutes of exposure of the internal surfaces of the glass vessel are sufficient to complete the treatment

Development of field ionization for the improvement of mass spectrometry Interim scientific report, 25 Mar. 1968 - 25 Mar. 1969

Field ionization for improvment of mass spectrometr

Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Summary technical report, 1 Feb. 1965 - 1 Mar. 1966

Cryosorption, diffusion pump, and pressure calibration studies in extreme vacuum science and technology application progra

Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Quarterly status report no. 8, 1 May - 1 Aug. 1965

Cryosorption, diffusion pump, and low pressure calibration studies on Penning gauge and cold cathode magnetro

Study of low pressure application of the orbitron

Evaluation of low pressure performance of orbitron ionization gaug

Integration of psychological models in the design of artificial creatures

Artificial creatures form an increasingly important component of interactive computer games. Examples of such creatures exist which can interact with each other and the game player and learn from their experiences. However, we argue, the design of the underlying architecture and algorithms has to a large extent overlooked knowledge from psychology and cognitive sciences. We explore the integration of observations from studies of motivational systems and emotional behaviour into the design of artificial creatures. An initial implementation of our ideas using the “sim agent” toolkit illustrates that physiological models can be used as the basis for creatures with animal like behaviour attributes. The current aim of this research is to increase the “realism” of artificial creatures in interactive game-play, but it may have wider implications for the development of AI

Optical/Infrared Observations of the Anomalous X-ray Pulsar 1E 1048.1-5937 During Its 2007 X-Ray Flare

We report on optical and infrared observations of the anomalous X-ray pulsar (AXP) 1E 1048.1-5937, made during its ongoing X-ray flare which started in 2007 March. We detected the source in the optical I and near-infrared Ks bands in two ground-based observations and obtained deep flux upper limits from four observations, including one with the Spitzer Space Telescope at 4.5 and 8.0 microns. The detections indicate that the source was approximately 1.3--1.6 magnitudes brighter than in 2003--2006, when it was at the tail of a previous similar X-ray flare. Similar related flux variations have been seen in two other AXPs during their X-ray outbursts, suggesting common behavior for large X-ray flux variation events in AXPs. The Spitzer flux 1E 1048.1-5937 limits are sufficiently deep that we can exclude mid-infrared emission similar to that from the AXP 4U 0142+61, which has been interpreted as arising from a dust disk around the AXP. The optical/near-infrared emission from probably has a magnetospheric origin. The similarity in the flux spectra of 4U 0142+61 and 1E 1048.1-5937 challenges the dust disk model proposed for the latter.Comment: 5 pages, 1 figure, accepted by Ap

Extreme vacuum technology developments

Ultrahigh vacuum environments technology development

Calibrated Sub-Bundles in Non-Compact Manifolds of Special Holonomy

This paper is a continuation of math.DG/0408005. We first construct special Lagrangian submanifolds of the Ricci-flat Stenzel metric (of holonomy SU(n)) on the cotangent bundle of S^n by looking at the conormal bundle of appropriate submanifolds of S^n. We find that the condition for the conormal bundle to be special Lagrangian is the same as that discovered by Harvey-Lawson for submanifolds in R^n in their pioneering paper. We also construct calibrated submanifolds in complete metrics with special holonomy G_2 and Spin(7) discovered by Bryant and Salamon on the total spaces of appropriate bundles over self-dual Einstein four manifolds. The submanifolds are constructed as certain subbundles over immersed surfaces. We show that this construction requires the surface to be minimal in the associative and Cayley cases, and to be (properly oriented) real isotropic in the coassociative case. We also make some remarks about using these constructions as a possible local model for the intersection of compact calibrated submanifolds in a compact manifold with special holonomy.Comment: 20 pages; for Revised Version: Minor cosmetic changes, some paragraphs rewritten for improved clarit