7,910 research outputs found
Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy
This is the second Semiannual Report submitted under Grant NAGW-509 for the development of a Balloon-Borne Three-Meter Telescope for Far-Infrared and Submillimeter Astronomy. It covers the period 1 March 1984 through 31 August 1984. This grant covers work at the Smithsonian Astrophysical Observatory (SAO), University of Arizona (UA) and the University of Chicago (UC). SAO is responsible for program management, the gondola structure including the attitude control and aspect systems, mechanical systems, and telemetry and command systems; the UA is responsible for optics design and fabrication; the UC is responsible for determining provisions for focal-plane instrumentation. SAO and the UA share responsibility for the ground support data and control computer
Definition phase effort of the Spacelab-2 Infrared Telescope Experiment (IRT)
Activities associated with a proposal for the reflight of the small helium cooled infrared telescope scheduled to make its maiden voyage on Spacelab-2 are reported. The experiments requirements document was revised and updated and an investigation development plan was prepared for the refurbishment and reflight of the telescope. The summary of a briefing held to discuss Spacelab interfaces for the proposal is included
Infrared measurements of spacecraft glow planned for Spacelab 2
A liquid helium cooled infrared telescope (IRT) was to be flown in July 1985 on Spacelab 2. The instrument is designed to measure both diffuse and discrete infrared astronomical sources, including the zodiacal light, galactic, and extragalactic components, as well as to evaluate the induced Orbiter environment. The focal plane contains ten photoconductive detectors covering six broad bands from 2 to 120 microns. Each detector has a 0.5 by 1.0 deg field of view optimized for detection of extended sources of IR radiation. Except for the 2 micron detector, the system noise is limited by the sky background noise. The measurements planned for the IRT use the 1 meter base of the Plasma Diagnostic Package (PDP), an already existing SL 2 experiment, as the glow generating surface. The measurements are repeated changing the position of the PDP, the attitude of the Orbiter, and the ram direction in an effort to remove both the thermal component of the PDP emission and the cosmic background radiation
Institutional environment, innovative entrepreneurial entry and venture capital financing
We analyse the determinants of high growth expectations entrepreneurial entry (HGE) using individual data drawn on working age population, based on the Global Entrepreneurship Monitor (GEM) surveys for the 1998-2004 period. Individual level explanatory variables are combined with country-level factors. Our results suggest that availability of venture capital and intellectual proper rights protection are strong predictors of HGE. In addition, we also find that innovative start-ups are associated with highest growth expectations in countries with extensive supply of venture capital and strongest intellectual property rights. Once we introduce venture capital, we detect no significant effects of other elements of financial systems on high-powered entry
Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy
The study and revision of the gimbal design of the Three-Meter Balloon Borne Telescope (TMBBT) is discussed. Efforts were made to eliminate the alignment and limited rotation problems inherent in the flex-pivot design. A new design using ball bearings to replace the flex-pivots was designed and its performance analyzed. An error analysis for the entire gondola pointing system was also prepared
Prediction of the diffuse far infrared flux from the galactic plane
A basic model and simple numerical relations useful for future far infrared studies of the galaxy are presented. Making use of recent CO and other galactic surveys, the diffuse far infrared flux distribution from the galactic plane as a function of galactic longitude alternate theta for 4 deg or = alternate theta or = 90 and the far infrared emissivity as a function of galactocentric distance is predicted. Future measurements of the galactic far infrared flux would yield valuable information on the physical properties and distribution of dust and molecular clouds in the galaxy, particularly the inner region
Predicted high energy break in the isotropic gamma ray spectrum - A test of cosmological origin
Critical test of cosmological pion decay hypothesis for origin of isotropic gamma radiation above 1 Me
Andreev tunneling into a one-dimensional Josephson junction array
In this letter we consider Andreev tunneling between a normal metal and a one
dimensional Josephson junction array with finite-range Coulomb energy. The
characteristics strongly deviate from the classical linear Andreev
current. We show that the non linear conductance possesses interesting scaling
behavior when the chain undergoes a T=0 superconductor-insulator transition of
Kosterlitz-Thouless-Berezinskii type. When the chain has quasi-long range
order, the low lying excitation are gapless and the curves are power-law
(the linear relation is recovered when charging energy can be disregarded).
When the chain is in the insulating phase the Andreev current is blocked at a
threshold which is proportional to the inverse correlation length in the chain
(much lower than the Coulomb gap) and which vanishes at the transition point.Comment: 8 pages LATEX, 3 figures available upon reques
Role of the target orientation angle and orbital angular momentum in the evaporation residue production
The influence of the orientation angles of the target nucleus symmetry axis
relative to the beam direction on the production of the evaporation residues is
investigated for the Ca+Sm reaction as a function of the beam
energy. At low energies (137 MeV), the yield of evaporation
residues is observed only for collisions with small orientation angles
().
At large energies (about 140--180 MeV) all the orientation
angles can contribute to the evaporation residue cross section
in the 10--100 mb range, and at 180 MeV
ranges around 0.1--10 mb because the fission barrier for a compound nucleus
decreases by increasing its excitation energy and angular momentum.Comment: 20 pages, 10 figures, submitted to JPS
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