Search

During a Martian dust storm, the lower atmosphere is heated locally. Due to dynamical effects, the upper atmosphere and ionosphere can be lifted upward on a global scale by approximately 10 km. The connections between lower atmospheric dust events and associated ionospheric responses are poorly understood due to limited observations. Here, we present MAVEN Radio Occultation Science Experiment (ROSE) observations of ionospheric peak altitude during dust events in 2018 and 2016. In June 2018, a planet-encircling dust event arose from the Acidalia storm track in the northern hemisphere. Ionospheric peak altitudes at around 20°S were normal in ROSE egress observations on 19 June and 22 June and then 10–15 km higher on 26 June and thereafter. Ionospheric peak altitudes at around 50°N were also elevated in ROSE ingress observations, which began on 17 June. This suggests that the ionospheric peak altitude was affected by the dust event in the northern hemisphere before the southern hemisphere. We also observe evidence that smaller dust storms can trigger ionospheric responses: In July–October 2016, ionospheric peak altitudes at solar zenith angles of 54–70° and latitudes of 50–80°S were 20 km higher than expected. These observations were acquired during a modest “A storm” during a year without a global dust storm. ©2020. American Geophysical Union. All Rights Reserved.

We describe the first demonstration of a Southern Hemisphere planetary radar system to detect two near-Earth asteroids (NEAs). The demonstration was conducted in a bistatic manner, with the 70 m antenna of the Canberra Deep Space Communications Complex transmitting at 2.1 GHz and reception at the Parkes Radio Telescope, outfitted with multiple receivers, and the Australia Telescope Compact Array. This initial system was used to detect the NEAs (43577) 2005 UL5 and (33342) 1998 WT24 during their close approaches in 2015 November and 2015 December, respectively. We describe the performance of the system and consider future possibilities using other antennas of the Canberra Deep Space Communications Complex as transmitters.

Übersicht aus sozialwissenschaftlicher Perspektive zur Kommunikation über Biotechnologie in Europa

The Mars Express spacecraft is operating in Mars orbit since early 2004. The Mars Express Radio Science Experiment (MaRS) employs the spacecraft and ground station radio systems (i) to conduct radio occultations of the atmosphere and ionosphere to obtain vertical profiles of temperature, pressure, neutral number densities and electron density, (ii) to conduct bistatic radar experiments to obtain information on the dielectric and scattering properties of the surface, (iii) to investigate the structure and variation of the crust and lithosphere in selected target areas, (iv) to determine the mass, bulk and internal structure of the moon Phobos, and (v) to track the MEX radio signals during superior solar conjunction to study the morphology of coronal mass ejections (CMEs). Here we report observations, results and discoveries made in the Mars environment between 2004 and 2014 over almost an entire solar cycle. (C) 2016 Elsevier Ltd. All rights reserved.

Data are presented on evaluated Knight Shifts in alloys together with other solid state properties with Cu-Zn., See also Part 4, AD-D095 429.

Contents: Part IV, Addenda to review Chapters and NMR tables, Resonance Index - an alphabetical index of metals and alloys in which a particular nuclear resonance has been observed or discussed in the evaluation, and Journal abbreviations., See also Part 1, AD-D095 426.

The present works deals almost exclusively with critically evaluated Knight shift data. Quadrupole effects and relaxation time data, and NMR in ferromagnetic materials are considered with less completeness., See also Part 3, AD-D095 428.

The present work deals almost exclusively with critically evaluated Knight shift data. Quadrupole effects and relaxation time data, and NMR in ferromagnetic materials are considered with less completeness. The Knight shift, which is measured almost exclusively by the NMR technique, has far-reaching applications in solid state physics, physical metallurgy, and other areas. For instance, it is very sensitive to details of a metal's Fermi surface, and to changes in the Fermi surface caused by alloying, and thus can serve as a sensitive test of models proposed to explain the electronic structure of metals. It is also an important analytical chemical or metallurgical tool in both basic and applied studies. For example, the NMR of metals such as cesium is used for precise measurement of magnetic fields and applications of NMR to phase diagram determinations. NMR theory is reviewed in Chapters 1 through 4, data reduction techniques are discussed in Chapters 5 and 6, and metallurgical applications of NMR are described in Chapter 7. Critical evaluation methods and coverage are detailed in Chapter 8, and the evaluated Knight shifts, together with many other physical properties that have been evaluated to a lesser extent, are treated in Chapter 9. There are summarizing tables both in Chapter 9 and in the review chapters as pertinent to the text. For example, nuclear spin-lattice relaxation times and Korringa ratios for solid nontransition metals are given in Table 2.4, and pressure dependence parameters of the Knight shift for elemental metals in Table 4.1., See also Part 2, AD-D095 427.

Copepods are an important link in the marine food web, and, in particular, serve as food for fish larvae. Schizopera elatensis, a marine harpacticoid copepod, was reared in the laboratory, and the effect of various environmental factors, i.e., diet, temperature, salinity and height of water column on its growth was determined. Schizopera elatensis multiplies at a wide range of salinities, 10‰ to 70‰, and temperatures, from at least 18° C to an upper limit of 36° C, with an optimum of 25° C, and grows in high densities (300-400 individuals per ml): the lower the water column, the higher the density. The prospective use of S. elatensis as a live food organism in mariculture is discussed.

The Alloy Data Center, part of the National Standard Reference Data System, has two primary functions. One is to stimulate cooperation and coordination among the existing data centers in the area of the physical properties of well characterized alloys. The final data generated by these centers for publication should be consistent with one another where correlation or possible overlap exists. The other purpose is the collection (from publications as well as private communications), evaluation, and publication of data in some areas where special competence exists in the Alloy Physics Section. Of interest to the center are metals, semimetals, intermetallic compounds, and alloys. Excluded are those materials which have ill-defined constitution and heat treatments. An automated system has been developed to meet the bibliographic needs of the center. This system will be described as well as the specific properties of interest. The system presently contains a complete annotated file on papers dealing with NMR Knight shift measurements. The soft X-ray spectroscopy compilation is being kept up-to-date with the same system. (Author)

This Index contains literature references to approximately 10,000 research papers on physical properties of metals and alloys. The Index contains all NMR Knight shift papers and soft x-rays emission papers. It also contains many soft x-ray absorption papers and a number of papers on generally related topics such as susceptibilities, specific heats, hyperfine fields, and band structures. The papers are annotated in depth and the coded information put onto a magnetic tape. The Permuted Materials Index was created from this tape, listing alloys under each of their constituent components (i.e., CuNi appears under CuNi and under NiCu alloys). (Author)