German Source Materials in American Libraries

https://epublications.marquette.edu/mupress-book/1003/thumbnail.jp

The high latitude outer zone boundary for more than or equal to 40 keV electrons as observed by satellite Injun 3

High latitude outer zone boundary for greater than or equal to 40 keV electrons observed by Injun 3 satellit

Interplay of disorder and interactions in subcritically tilted and anisotropic three-dimensional Weyl fermions

We study the effects of disorder and Coulomb interactions on the physics of three-dimensional type-I Weyl fermions with tilted and anisotropic dispersions in a renormalization group approach. To lowest non-trivial loop order we show that the tendency of the Coulomb interactions to restore the symmetry of the dispersion in the semimetallic region of the phase diagram dominates the stabilization of the tilt and anisotropy favored by weak disorder. We argue that the topology of the renormalization flow of the disorder and Coulomb couplings is essentially determined by gauge invariance, so that these findings continue to hold qualitatively at any order in perturbation theory.Comment: 9+5 page

Diurnal and latitude effects observed for 10 key electrons at low satellite altitudes

Observing diurnal and latitude effects for 10 keV electrons on low altitude, high latitude satellite Injun III using low energy electron detecto

Ring current proton decay by charge exchange

Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles

Massive binaries in the vicinity of Sgr A*

A long-term spectroscopic and photometric survey of the most luminous and massive stars in the vicinity of the super-massive black hole Sgr A* revealed two new binaries; a long-period Ofpe/WN9 binary, GCIRS 16NE, with a modest eccentricity of 0.3 and a period of 224 days and an eclipsing Wolf-Rayet binary with a period of 2.3 days. Together with the already identified binary GCIRS 16SW, there are now three confirmed OB/WR binaries in the inner 0.2\,pc of the Galactic Center. Using radial velocity change upper limits, we were able to constrain the spectroscopic binary fraction in the Galactic Center to $F_{\rm SB}=0.27^{+0.29}_{-0.19}$ at a confidence level of 95%, a massive binary fraction similar to that observed in dense clusters. The fraction of eclipsing binaries with photometric amplitudes $\Delta m>0.4$ is $F^{\rm GC}_{\rm EB}=3\pm2$, which is consistent with local OB star clusters ($F_{\rm EB}=1$). Overall the Galactic Center binary fraction seems to be close to the binary fraction in comparable young clusters.Comment: 5 figures, submitted to Ap

Trophodynamics of estuarine (salt marsh) heterotrophic nanoplankton (microbial ecology, salt marsh ecology, choanoflagellates, Virginia)

Seasonal occurrence and activity of heterotrophic nanoflagellates (HNANO or heteroflagellates) and bacteria were studied in a sheltered brackish water embayment of Chesapeake Bay wetlands (Virginia, USA) over a three year period (1981 - 1984). Epifluorescence direct counts and Scanning and Transmission Electron Microscopy (SEM and TEM) techniques were used for the description of organisms, enumeration, and biomass determinations. Seasonal bacterial growth rates and growth and grazing rates of bactivorous HNANO were estimated using diffusion chambers equipped with Nuclepore polycarbonate membrane filters in natural salt marsh tidal pools. Environmental monitoring of nanoplankton populations revealed a seasonal pattern of bacterial abundances with temperature while heteroflagellate abundances and growth rates showed no seasonal pattern nor correlation with fluctuations in bacterial densities. Heteroflagellate populations were dominated by 34 to 50 (mu)m(\u273) sized monads, choanoflagellates, bodonids, and Paraphysomonas sp., all found in varying abundances throughout the year. Blooms were concurrent with extended low tide or specific bacterial populations (i.e., cyanobacteria) typical of spring and autumn periods. Heteroflagellate growth in diffusion chambers reflected the environmental blooms and increased diversity of low water assemblages. Growth and grazing rates of heteroflagellates at ambient densities thus could account for 20 to 80% of daily bacterial carbon production. Although heteroflagellate ingestion rates did not regulate seasonal bacteria densities or vice versa, maximum growth of bacteria and heteroflagellates in chambers was closely coupled. Heteroflagellate grazing activity may regulate the rate of bacterial production by preventing substrate limitation and maintaining the population in an active growth phase. The seasonal study demonstrated the dynamic nature of nanoplankton populations during autumn and spring transitional periods. SEM photomicroscopy revealed that the dominant component of spring blooms may be composed of several members of the loricate choanoflagellate family, Acanthoecidae. Using modified EM techniques, eleven Acanthoecidae choanoflagellates species, identified from spring in situ chamber experiments, were described. In situ growth and grazing rates for the spring chamber populations ranged from 0.023 h(\u27-1) to 0.196 h(\u27-1) and 40 to 210 bacteria h(\u27-1) respectively. These high rates represent an opportunistic response to optimum conditions and an expression of maximum grazing potential. (Abstract shortened with permission of author.)

Protons as the prime contributors to the storm time ring current

Following a large magnetic storm (17 June 1972), Explorer 45 measured the equatorial particle populations and magnetic field. Using data obtained during the symmetic recovery phase, it is shown that through a series of self-consistent calculations, the measured protons with energies from 1 to 872 keV, can account for the observed ring current magnetic effects within experimental uncertainities. This enables an upper limit to be set for the heavy ion contribution to the storm time ring current