Liquid-metal-piston MHD generator

Magnetohydrodynamic generator uses a slug or piston of liquid potassium as the working fluid. An expanding vapor of the metal is allowed to reciprocate the liquid-metal-piston through a magnetic field and the expansion energy is converted directly into electrical energy

Regulation of anti-inflammatory gene expression in vascular endothelial cells by EPAC1

Suppressor of cytokine signalling 3 (SOCS3) is a potent inhibitor of pro-inflammatory pathways involved in atherogenesis and the development of neo-intimal hyperplasia (NIH), which contributes to the in-stent re-stenosis responsible for the failure of percutaneous coronary intervention (PCI) procedures. We have shown that cyclic AMP sensor EPAC1 triggers induction of the SOCS3 gene in vascular endothelial cells (VECs), thereby attenuating interleukin 6 (IL-6)-mediated pro-inflammatory signalling. We propose that EPAC1 localisation to the nuclear pore controls cyclic AMP-mediated activation of a C/EBPβ/c-Jun transcriptional complex, leading to SOCS3 induction and suppression of pro-inflammatory signalling. Future work in this area will involve an integrated approach to determine the wider significance of the EPAC1-C/EBPβ/c-Jun pathway in controlling human VEC function and identify new therapeutic targets for management of chronic inflammation in vascular settings

Higher diversity of Rhizobium leguminosarum biovar viciae populations in arable soils than in grass soils

The bacterial genetic diversity after long-term arable cultivation was compared with that under permanent grassland using replicated paired contrasts, Pea-nodulating Rhizobium leguminosarum populations were sampled from pairs of arable and grass sites at four locations in Yorkshire, United Kingdom, isolates were characterized using both chromosomal (16S-23S ribosomal DNA internal transcribed spacer PCR-restriction fragment length polymorphism) and plasmid (group-specific repC PCR amplification) markers. The diversities of chromosomal types, repC profiles, and combined genotypes were calculated using richness in types (adjusted to equal sample sizes by rarefaction), Shannon-Wiener index, and Simpson's index. The relative differences in diversity within each pair of sites were similar for all three diversity measures, Chromosomal types, repC profiles, and combined genotypes were each more diverse in arable soils than in grass soils at two of the four locations. The other comparisons showed no significant differences. We conclude that rhizobial diversity can be affected by differences between these two management regimens. Multiple regression analyses indicated that lower diversity was associated with high potential nitrogen and phosphate levels or with acidity

Spectroradiometric calibration of the thematic mapper and multispectral scanner system

The results of an analysis that relates thematic mapper (TM) saturation level to ground reflectance, calendar date, latitude, and atmospheric condition is provided. A revised version of the preprint included with the last quarterly report is also provided for publication in the IEEE Transactions on Geoscience and Remote Sensing

Spectroradiometric calibration of the Thematic Mapper and Multispectral Scanner system

The effects of the atmosphere on propagating radiation must be known in order to calibrate an in orbit sensor using ground based measurements. A set of model atmosphere parameters, applicable to the White Sands (New Mexico) area is defined with particular attention given to those parameters which are required as input to the Herman Code. The radial size distribution, refractive index, vertical distribution, and visibility of aerosols are discussed as well as the molecular absorbers in the visible and near IR wavelength which produce strong absorption lines. Solar irradiance is also considered

Spectroradiometric calibration of the Thematic Mapper and Multispectral Scanner system

The results of analyses of Thematic Mapper (TM) images acquired on July 8 and October 28, 1984, and of a check of the calibration of the 1.22-m integrating sphere at Santa Barbara Research Center (SBRC) are described. The results obtained from the in-flight calibration attempts disagree with the pre-flight calibrations for bands 2 and 4. Considerable effort was expended in an attempt to explain the disagreement. The difficult point to explain is that the difference between the radiances predicted by the radiative transfer code (the code radiances) and the radiances predicted by the preflight calibration (the pre-flight radiances) fluctuate with spectral band. Because the spectral quantities measured at White Sands show little change with spectral band, these fluctuations are not anticipated. Analyses of other targets at White Sands such as clouds, cloud shadows, and water surfaces tend to support the pre-flight and internal calibrator calibrations. The source of the disagreement has not been identified. It could be due to: (1) a computational error in the data reduction; (2) an incorrect assumption in the input to the radiative transfer code; or (3) incorrect operation of the field equipment

Spectroradiometric calibration of the Thematic Mapper and Multispectral Scanner system

The reduction of the data measured on July 8, 1984 at White Sands, New Mexico is summarized. The radiance incident at the entrance pupil of the LANDSAT 5 sensors have been computed for bands 1 to 4. When these are compared to the digital counts of the TM image, the ground based calibration for this sensor will be given. The image was received from Goddard SFC and is presently being analyzed

Spectroradiometric calibration of the thematic mapper and multispectral scanner system

The results obtained for the absolute calibration of TM bands 2, 3, and 4 are presented. The results are based on TM image data collected simultaneously with ground and atmospheric data at White Sands, New Mexico. Also discussed are the results of a moments analysis to determine the equivalent bandpasses, effective central wavelengths and normalized responses of the TM and MSS spectral bands; the calibration of the BaSO, plate used at White Sands; and future plans

Spectroradiometric calibration of the Thematic Mapper and multispectral scanner system

The eleventh quarterly report on Spectroradiometric Calibration of the Thematic Mapper (Contract NAS5-27832) discusses calibrations made at White Sands on 24 May 1985. An attempt is made to standardize test results. Critical values used in the final steps of the data reduction and the comparison of the results of the pre-flight and internal calibration (IC) data are summarized

Spectroradiometric calibration of the Thematic Mapper and Multispectral Scanner system

The newly built Caste spectropolarimeters gave satisfactory performance during tests in the solar radiometer and helicopter modes. A bandwidth normalization technique based on analysis of the moments of the spectral responsivity curves was used to analyze the spectral bands of the MSS and TM subsystems of LANDSAT 4 and 5 satellites. Results include the effective wavelength, the bandpass, the wavelength limits, and the normalized responsivity for each spectral channel. Temperature coefficients for TM PF channel 6 were also derived. The moments normalization method used yields sensor parameters whose derivation is independent of source characteristics (i.e., incident solar spectral irradiance, atmospheric transmittance, or ground reflectance). The errors expected using these parameters are lower than those expected using other normalization methods