256 research outputs found

    LUNAR HEAT FLOW EXPERIMENT LONG TERM TEMPERATURE OBSERVATIONS ON THE LUNAR SURFACE AT APOLLO SITES 15 AND 17 by

    Get PDF
    Reproduction in whole or in part is permitted for any purpose of the United States Government. Others must secure the author's permis sian for use of this material. Distribution of this document is unlimited. ii TABLE OF CONTENTS Abstract...................................................... ii

    Structure of the western Somali Basin

    Get PDF
    Originally issued as Reference No. 67-38, series later renamed WHOI-. Reprint from Journal of Geophysical Research, vol. 72, no. 10, May 1967.The western Somali Basin in the northwestern Indian Ocean is covered by thick deposits of terrigenous sediments. Seismic reflection profiles show, however, the northern and southern parts to be very different. The northern sections is a deep basin filled with thick uniformly stratified sediments. It is enclosed by the continental margin to the west and north, Chain ridge to the east, and shallow basement structure to the south. A change in depth of basement occurs along an approximately east-west line at latitude 3°30'N very near the southern end of Chain ridge. In the southern portion of the basin the basement is shallow, and, immediately south of latitude 3°30'N, it has high relief. Stratified flat-lying sediments fill the basement depressions, and isolated hills formed of basement material rise above the abyssal plain deposits. Farther to the south the abyssal plain becomes very narrow. Gabbro dredged from the southeast slope of Chain ridge has been dated by the potassium-argon method as 89.6 ± 4.5 m.y., which should be considered a minimum age. The evidence suggests that the entire sediment sequence of the northern basin was deposited subsequent to the formation of the ridge. The thin sediment cover of the southern portion of the basin is probably no older than Tertiary.Office of Naval Research under contract Nonr-4029(00) NR 260-101

    Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR) can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today.</p> <p>Methods</p> <p>Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations.</p> <p>Results</p> <p>Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects.</p> <p>Conclusion</p> <p>Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking complements and provides incremental information compared to particle tracing that may lead to a better understanding of blood flow and may improve diagnosis and prognosis of cardiovascular diseases.</p

    Quarterly Progress Report No. 1 July-September 1969 on Contract NAS 9-6037

    No full text
    During the report period the main effort at Lamont-Doherty Geological Observatory has been to complete preparations for real time data reduction at MSC. Two documents have been submitted to MSC: 1) describing the reduction of ALSEP data in terms of temperatures and temperature differences as a function of time, 2) describing the reduction and interpretation of the conductivity data in real time at MSC.Marcus G. Langseth, Jr. Principal Investigato
    corecore