1,547 research outputs found
A comparison of superconductor and manganin technology for electronic links used in space mission applications
The electronic link connecting cryogenically cooled radiation detectors to data acquisition and signal processing electronics at higher temperatures contributes significantly to the total heat load on spacecraft cooling systems that use combined mechanical and cryogenic liquid cooling. Using high transition temperature superconductors for this link has been proposed to increase the lifetime of space missions. Herein, several YBCO (YBa2Cu3O7) superconductor-substrate combinations were examined and total heat loads were compared to manganin wire technology in current use. Using numerical solutions to the heat-flow equations, it is shown that replacing manganin technology with YBCO thick film technology can extend a 7-year mission by up to 1 year
Research and development of a high capacity, nonaqueous secondary battery Final report, Oct. 1964 - Dec. 1965
High capacity nonaqueous secondary batter
Research and development of a capacity nonaqueous secondary battery Fourth quarterly report, Jul. - Sep. 1965
High capacity nonaqueous secondary battery development - lithium deposition and cycling, ionic solvation, cathode construction and discharge efficiency, and solvent purificatio
Effect of reheating on predictions following multiple-field inflation
We study the sensitivity of cosmological observables to the reheating phase
following inflation driven by many scalar fields. We describe a method which
allows semi-analytic treatment of the impact of perturbative reheating on
cosmological perturbations using the sudden decay approximation. Focusing on
-quadratic inflation, we show how the scalar spectral index and
tensor-to-scalar ratio are affected by the rates at which the scalar fields
decay into radiation. We find that for certain choices of decay rates,
reheating following multiple-field inflation can have a significant impact on
the prediction of cosmological observables.Comment: Published in PRD. 4 figures, 10 page
Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation
The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance
Runoff Losses of Atrazine, Metribuzin, and Nutrients as Affected by Management Practices for Sugarcane (Bulletin #875)
A primary objective of this investigation was to evaluate the effectiveness of selected pesticide management practices on the movement of atrazine and metribuzin in surface runoff from sugarcane fields in south Louisiana.https://digitalcommons.lsu.edu/agcenter_bulletins/1026/thumbnail.jp
Effect of Application Frequency on the Fate of Azinphosmethyl in a Sugercane Field (Bulletin #863)
Reducing the amounts of dissolved substances in surface and ground water is of major concern nationally and within the agricultural community. The primary focus of this study was to investigate the fate of azinphosmethyl (Guthion®) in sugarcane canopy, soil and runoff water.https://digitalcommons.lsu.edu/agcenter_bulletins/1014/thumbnail.jp
Rapid Generation of a Macroscopic Schr\"odinger Cat State of Atoms with Parity-Independent Orientation
We show that using the process of one-axis-twist squeezing in an echo
configuration, it is possible to control the orientation of the macroscopic
magnetic moment of a large number of atoms by manipulating the quantum state of
a single atom that is physically isolated from the ensemble. With this control
technique, it is also possible to entangle an ensemble with a single atom
deterministically, which mimics the thought experiment known as the
Schr\"odinger cat. In addition, this technique would make it possible to
generate a mesoscopic Schr\"odinger cat state for a large number of atoms far
more rapidly that the conventional process for generating such a state, with an
orientation that is independent of the parity of the number of atoms. Apart
from the echo configuration, we have also investigated the behavior of
one-axis-twist squeezing for some special values of the squeezing parameter. We
find that the squeezing propagator can be expressed as the sum of n rotation
operators if the product of n and the squeezing parameter equals pi, where n is
a non-zero integer. A direct consequence of this property of one-axis-twist
squeezing is that there is a hidden order in a squeezed state generated under
this condition even if its Husimi quasi-probability distribution looks
irregular
Development of superconducting YBa2Cu3O(x) wires with low resistance electrical contacts
Materials exhibiting superconductivity above liquid nitrogen temperatures (77 K) will enable new applications of this phenomena. One of the first commercial applications of this technology will be superconducting magnets for medical imaging. However, a large number of aerospace applications of the high temperature superconducting materials have also been identified. These include magnetic suspension and balance of models in wind tunnels and resistanceless leads to anemometers. The development of superconducting wires fabricated from the ceramic materials is critical for these applications. The progress in application of a patented fiber process developed by Clemson University for the fabrication of superconducting wires is reviewed. The effect of particle size and heat treatment on the quality of materials is discussed. Recent advances made at Christopher Newport College in the development of micro-ohm resistance electrical contacts which are capable of carrying the highest reported direct current to this material is presented
- …