Aeronautical Engineering: A special bibliography, supplement 60

This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

Aeronautical engineering: A continuing bibliography, supplement 122

This bibliography lists 303 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1980

Binary neutron star mergers and electromagnetic counterparts

In August 2017, a merger of two neutron stars (NSs) was detected for the first time via several carriers. Observed in gravitational waves, as well as in the electromagnetic spectrum, the GW170817 marked the dawn of multi-messenger astronomy for compact object mergers, and shed light on numerous astrophysical aspects of binary neutron star (BNS) mergers and on the properties of matter at supranuclear densities. And yet many questions remain, starting with the outcome of the merger. Was it a massive NS temporarily supported against collapse, or a black hole? How important are BNS mergers in cosmic chemical evolution, i.e., the evolution of spatial and temporal distributions of heavy elements in galaxies? It is known that they enrich their surroundings with very heavy elements, but are they the dominant source of these elements? Modeling these events on the computer, do we understand them correctly, i.e., do our predictions regarding the properties of the ejected matter and its EM signatures agree with the newly gained data? This thesis is dedicated to addressing these questions by means of analyzing a large set of numerical simulations of BNS mergers, performed with state-of-the-art numerical tools, and targeted specifically to GW170817. Employing a suite of postprocessing tools we study the matter dynamics. Special attention is given to matter, ejected from the system during and after merger, so-called ejecta. With the help of a parameterized nucleosynthesis model, we study the final abundances of heavy elements in ejecta, comparing them to solar abundances. Furthermore, we investigate EM emission, powered by the decay of newly synthesized heavy elements, comparing it to the observations of GW170817. Finally, we study the long-term emission of the ejected material as it propagates through the interstellar medium (ISM), via our new numerical tools, comparing the results with a recently detected change in the emission from GW170817

Dynamical Systems

Complex systems are pervasive in many areas of science integrated in our daily lives. Examples include financial markets, highway transportation networks, telecommunication networks, world and country economies, social networks, immunological systems, living organisms, computational systems and electrical and mechanical structures. Complex systems are often composed of a large number of interconnected and interacting entities, exhibiting much richer global scale dynamics than the properties and behavior of individual entities. Complex systems are studied in many areas of natural sciences, social sciences, engineering and mathematical sciences. This special issue therefore intends to contribute towards the dissemination of the multifaceted concepts in accepted use by the scientific community. We hope readers enjoy this pertinent selection of papers which represents relevant examples of the state of the art in present day research. [...

Bibliography of Lewis Research Center technical publications announced in 1989

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1989. All the publications were announced in the 1989 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses