8,434 research outputs found
Performance of differenced range data types in Voyager navigation
Voyager radio navigation made use of a differenced rage data type for both Saturn encounters because of the low declination singularity of Doppler data. Nearly simultaneous two-way range from two-station baselines was explicitly differenced to produce this data type. Concurrently, a differential VLBI data type (DDOR), utilizing doubly differenced quasar-spacecraft delays, with potentially higher precision was demonstrated. Performance of these data types is investigated on the Jupiter-to-Saturn leg of Voyager 2. The statistics of performance are presented in terms of actual data noise comparisons and sample orbit estimates. Use of DDOR as a primary data type for navigation to Uranus is discussed
Radiation effects on silicon solar cells Final report, Dec. 1, 1961 - Dec. 31, 1962
Displacement defects in silicon solar cells by high energy electron irradiation using electron spin resonance, galvanometric, excess carrier lifetime, and infrared absorption measurement
Equivalences between spin models induced by defects
The spectrum of integrable spin chains are shown to be independent of the
ordering of their spins. As an application we introduce defects (local spin
inhomogeneities in homogenous chains) in two-boundary spin systems and, by
changing their locations, we show the spectral equivalence of different
boundary conditions. In particular we relate certain nondiagonal boundary
conditions to diagonal ones.Comment: 14 pages, 16 figures, LaTeX, Extended versio
A deformed analogue of Onsager's symmetry in the XXZ open spin chain
The XXZ open spin chain with general integrable boundary conditions is shown
to possess a q-deformed analogue of the Onsager's algebra as fundamental
non-abelian symmetry which ensures the integrability of the model. This
symmetry implies the existence of a finite set of independent mutually
commuting nonlocal operators which form an abelian subalgebra. The transfer
matrix and local conserved quantities, for instance the Hamiltonian, are
expressed in terms of these nonlocal operators. It follows that Onsager's
original approach of the planar Ising model can be extended to the XXZ open
spin chain.Comment: 12 pages; LaTeX file with amssymb; v2: typos corrected,
clarifications in the text; v3: minor changes in references, version to
appear in JSTA
Neutrophil Trafficking in Pulmonary Inflammation: Monitoring Migration and Blockade with 111In-Labeled Leukocytes
AbstractAim: Although imaging of In vitro labeled leukocytes is commonly used for diagnosing inflammation and infection, data concerning the use of this technique to monitor neutrophil trafficking are scarce. Here we investigated thepotential of 111In-in vitro labeled leukocytes (InWBC) to monitor neutrophil trafficking in an animal model of pulmonary inflammation.Methods: F344 rats were divided into 3 groups: Controls (received only InWBC), Inflammation (intra-tracheally challenged with lipoteichoic acid (LTA)+peptidoglycan (PGN) two hours before InWBC injection), and Blockade(pulmonary challenge with receptor blockade [LTAPGN+Antileukinate, a CXC receptor 1 and 2 antagonist]). Leukocytes were obtained from donor rats and labeled with 111In-oxine using standard procedures. Labeling efficiencyand leukocyte integrity were determined. Animals were administered 3.7-4.6 MBq InWBC via the tail vein, and were imaged 18-30 hours later and then euthanized. Post mortem the lungs were lavaged and total and differential alveolar cell counts performed. Lung tissue myeloperoxidase (MPO) activity was determined. Lung, heart, liver, spleen, kidney, marrow, intestine, blood, and muscle were harvested and organ activity/gm tissue determined. Results: InWBC labeling efficiency and cell integrity were not significantly different among groups. InWBC pulmonary activity was significantly higher (p<0.0001) in the Inflammation group (17.10 ± 2.04%) than in the Controls (1.76 ± 0.60%) and the Blockade group (9.74 ± 1.14%). Hemocytometer assessment of the bronchoalveolar lavage fluid revealed that the total number of neutrophils was significantly higher in the Inflammation group than in Controls and the Blockade group. Pulmonary MPO activity (pg/mg tissue) was significantly higher (p<0.01) in the Inflammation group (14.11 ± 5.56%) than in Controls (5.22 ± 4.77%) and the Blockade group (3.66 ± 3.77%). InWBC splenic activity was significantly higher (p<0.0001) in the Controls than in the Inflammation and Blockade groups. In the remaining organs, InWBC activity was significantly higher in the Blockade group than in the Control and the Inflammation groups.Conclusions: In a rat model of pulmonary inflammation using Antileukinate to block neutrophil chemokine receptors, InWBC accurately characterized both pulmonary and extrapulmonary neutrophil trafficking. These data indicate that InWBC may be useful to monitor both pulmonary and extrapulmonary neutrophil trafficking associated with lung inflammation and its regulation
High‐resolution time resolved spectroscopy of collisionless molecular beams. II. Energy randomization and optical phase relaxation of molecules in crossed laser and molecular beams
Hydrodynamic journal bearing program Quarterly progress report, 29 Apr. - 29 Jul. 1966
Hydrodynamic journal bearing instrumentation progra
A beta-ray spectrometer for coincidence measurements
An intermediate image beta-ray spectrometer has been constructed utilizing the focusing properties of a U-shaped magnetic field distribution. The construction and performance of the instrument are discussed. A transmission of ten percent has been attained with a resolution of about six percent. A scintillation spectrometer is used in conjunction with the intermediate image spectrometer for the purpose of making coincidence measurements
Hydrodynamic journal bearing program Quarterly progress report, Jan. 29 - Apr. 29, 1966
Fabrication and testing of hydrodynamic journal bearing for spacecraft power syste
Hydrodynamic journal bearing program Quarterly progress report no. 1, 29 May - 29 Jul. 1965
Test assembly design requirements for space power systems journal bearing
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