22,448 research outputs found
Advanced fiber-composite hybrids--A new structural material
Introduction of metal foil as part of matrix and fiber composite, or ""sandwich'', improves strength and stiffness for multidirectional loading, improves resistance to cyclic loading, and improves impact and erosion resistance of resultant fiber-composite hybrid structure
Test evaluation of fuel cell catalysts Quarterly report, 15 Feb. - 15 May 1967
Catalytic activity of iron compounds for fuel cell catalyst
Boron/aluminum graphite/resin advanced fiber composite hybrids
Fabrication feasibility and potential of an adhesively bonded metal and resin matrix fiber-composite hybrid are determined as an advanced material for aerospace and other structural applications. The results show that using this hybrid concept makes possible a composite design which, when compared with nonhybrid composites, has greater transverse strength, transverse stiffness, and impact resistance with only a small penalty on density and longitudinal properties. The results also show that laminate theory is suitable for predicting the structural response of such hybrids. The sequence of fracture modes indicates that these types of hybrids can be readily designed to meet fail-safe requirements
Differential proteolysis of insulin-like growth factor binding protein-1 (IGFBP-1) in pregnancy
The insulin-like growth factors and their binding proteins are important for placental and foetal growth. In this study, we have investigated the presence of proteolytic activity directed against insulin-like growth factor binding protein-1 (IGFBP-1) in pregnancy. In addition, the effect of protease activity on IGFBP-1 immunoreactivity and IGF binding was characterised. 125I-IGFBP-1 was incubated with maternal and foetal serum, amniotic fluid and placental extracts. Breakdown of 125I-IGFBP-1 was determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and autoradiography. The size distribution of endogenous IGFBP-1 was determined by Western immunoblotting. Protease inhibitor studies characterised the proteolytic activity, and Western ligand blotting with 125I-IGF-I was used to determine IGF binding capacity of proteolysed IGFBP-1. Amniotic fluid samples collected after labour onset contained proteolytic activity that generated 12- and 19-kDa IGFBP-1 fragments that did not bind to 125I-IGF-I. This activity was not detected in amniotic fluid collected prior to labour onset or in other tissues. Activity was blocked by aprotinin, leupeptin, phenyl methyl sulphonyl fluoride, and Kunitz soybean trypsin inhibitor but not by ethylene diamine tetraacetic acid or pepstatin. Incubation of IGFBP-1 with trypsin generated fragments of a similar size to the amniotic fluid protease. In conclusion, we have demonstrated the presence in vivo of a trypsin-like proteolytic activity that alters the IGF-binding function of IGFBP-1 in pregnancy
Simple processors of star tracker commands for stabilizing an inertially oriented satellite
Simple processors of star tracker commands for stabilizing inertially oriented satellit
Properties of nonaqueous electrolytes Quarterly report, 20 Dec. 1966 - 19 Mar. 1967
Properties of nonaqueous electrolytes - preparation of electrolytes, nuclear magnetic resonance structural studies, and physical property determination
Properties of nonaqueous electrolytes Quarterly report, 20 Jun. - 19 Sep. 1967
Electrolyte preparation, and physical property and nuclear magnetic resonance structural studies of nonaqueous electrolyte
The FHD/ppsilon Epoch of Reionization Power Spectrum Pipeline
Epoch of Reionization data analysis requires unprecedented levels of accuracy
in radio interferometer pipelines. We have developed an imaging power spectrum
analysis to meet these requirements and generate robust 21 cm EoR measurements.
In this work, we build a signal path framework to mathematically describe each
step in the analysis, from data reduction in the FHD package to power spectrum
generation in the ppsilon package. In particular, we focus on the
distinguishing characteristics of FHD/ppsilon: highly accurate
spectral calibration, extensive data verification products, and end-to-end
error propagation. We present our key data analysis products in detail to
facilitate understanding of the prominent systematics in image-based power
spectrum analyses. As a verification to our analysis, we also highlight a
full-pipeline analysis simulation to demonstrate signal preservation and lack
of signal loss. This careful treatment ensures that the
FHD/ppsilon power spectrum pipeline can reduce radio
interferometric data to produce credible 21 cm EoR measurements.Comment: 21 pages, 10 figures, accepted by PAS
The DMSP/MFR total ozone and radiance data base
This report describes the entries in sufficient detail so that the data base might be useful to others. The characteristics of the MFR sensor are briefly discussed and a complete index to the data base tapes is given
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