New circumstellar dust component in oxygen rich environments

Spectra of oxygen rich stars in the IRAS low-resolution spectra (LRS) catalog were found to display two distinct classes of curcumstellar excess emission. The first group has the normal silicate with emission peaking at 10 and 18 microns. The second group has an emission spectrum peaking at 13 and 20 microns. There are also spectra with a mixture of the above types. Generally the continuum temperature associated with the second group is much warmer than that associated with the normal silicate group. Laboratory spectra are compared with the new excess which associates the emission with a class of materials represented by hydrated aluminates and silicates. Possible interpretations include equilibrium condensation sequences and peculiar metal abundance ratios

Carbon stars with alpha-C:H emission

Many carbon stars in the IRS low resolution spectra (LRS) catalog were found which display emission spectra that compare favorable with the absorption spectrum of alpha-C:H. These stars have largely been classified as 4X in the LRS which has led to their interpretation by others in terms of displaying a mixture of the UIRF's 8.6 micron band and SiC at 11.5 microns. It was also found that many of these stars have a spectral upturn at 20+ microns which resembles the MgS band seen in carbon stars and planetary nebulae. It was concluded that this group of carbon stars will evolve into planetary nebulae like NGC 7027 and IC 418. In the presence of hard ultraviolet radiation the UIRF's will light up and be displayed as narrow emission bands on top of the broad alpha-C:H emission bands

Zeta Pegasi: An SPB Variable Star

Broadband photometric observations of the bright star Zeta Pegasi are presented that display brightness variability of 488.2 +/- 6.6 micromag (ppm) range with a period of 22.952 +/- 0.804 hr (f approx. equals 1.04566 c/d). The variation is monosinusoidal, so the star is recommended for membership in the class of small-amplitude Slowly Pulsating B-Stars (SPB) variables oscillating in a non-radial g-mode

Cryogenic measurements of aerojet GaAs n-JFETs

The spectral noise characteristics of Aerojet gallium arsenide (GaAs) junction field effect transistors (JFET's) have been investigated down to liquid-helium temperatures. Noise characterization was performed with the field effect transistor (FET) in the floating-gate mode, in the grounded-gate mode to determine the lowest noise readings possible, and with an extrinsic silicon photodetector at various detector bias voltages to determine optimum operating conditions. The measurements indicate that the Aerojet GaAs JFET is a quiet and stable device at liquid helium temperatures. Hence, it can be considered a readout line driver or infrared detector preamplifier as well as a host of other cryogenic applications. Its noise performance is superior to silicon (Si) metal oxide semiconductor field effect transistor (MOSFET's) operating at liquid helium temperatures, and is equal to the best Si n channel junction field effect transistor (n-JFET's) operating at 300 K

Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

Extended Life Qualification of the Magnetically Shielded Miniature (MaSMi) Hall Thruster

We present an update on the life qualification of the Magnetically Shielded Miniature (MaSMi) Hall thruster (also known as the ASTRAEUS Thruster Element), which was developed at the Jet Propulsion Laboratory and was recently licensed to ExoTerra Resource for flight production (renamed Halo12). In 2020-2021, the thruster successfully completed a 7205-hour wear test at operating powers from 200-1350 W, processing over 100 kg of xenon propellant and producing 1.55 MN-s total impulse with no measurable degradation in performance. The wear test is being extended to further demonstrate the service life capability of the thruster. In separate tests, prot-flight MaSMi hollow cathodes demonstrated \u3e 25000 ignition cycles and \u3e 13000 hours of operation at 4 A discharge current, and a set of three MaSMi electromagnets underwent \u3e 3000 deep thermal cycles (-123 °C to 495 °C). Laser-induced fluorescence (LIF) measurements of ion velocities and plasma modeling with Hall2De, a widely published numerical plasma code, have been carried out to elucidate the physical mechanisms driving pole erosion trends observed in thruster wear testing. Survival probabilities for micrometeoroid impacts and other random failure modes in flight were also analyzed

The open-air site of Tolbor 16 (Northern Mongolia): Preliminary results and perspectives.

Numerous questions remain regarding the timing and the context of Upper Paleolithic emergence in Northeast Asia. Available data allow the recognition of a form of Initial Upper Paleolithic (IUP) documented in the Altai circa 45e40 ka 14C BP, and in the Cis- and Transbaikal around �37 ka 14C BP. In Northern Mongolia, a series of assemblages show intriguing similarities with IUP laminar assemblages from South Siberia and suggest long distance contact/movements of population during the first half of MIS3. These contacts are potentially enabled by the main river that drains into Lake Baikal, the Selenga. By cutting through the Sayan and the Yablonovy mountain ranges, the Selenga drainage system provides a potential corridor connecting South Siberia with the plains of Mongolia. The Tolbor 16 site (Ikh Tulberiin Gol, Northern Mongolia) is located circa 13 km from the confluence with the Selenga. The first results presented here suggest that the lithic assemblage and the ornaments discovered at Tolbor 16 document the early appearance of Upper Paleolithic in the region. This newly discovered site offers the possibility to generate high-resolution contextual data on the first appearance of the blade assemblages in Mongolia and to test the ‘Selenga corridor hypothesis’

Deindustrialization and the Polarization of Household Incomes: The Example of Urban Agglomerations in Germany

The tertiarization, or perhaps more accurately, the deindustrialization of the economy has left deep scars on cities. It is evident not only in the industrial wastelands and empty factory buildings scattered throughout the urban landscape, but also in the income and social structures of cities. Industrialization, collective wage setting and the welfare state led to a stark reduction in income differences over the course of the twentieth century. Conversely, deindustrialization and the shift to tertiary sectors could result in increasing wage differentiation. Moreover, numerous studies on global cities, the dual city, and divided cities have also identified income polarization as a central phenomenon in the development of major cities. Using data from the German Socio-Economic Panel (SOEP), we find an increasing polarization of household income structures since the mid-1990. In agglomerations, this income polarization is even more pronounced than in the more rural regions. The income polarization in Germany is likely to have multiple causes, some of which are directly linked to policies such as the deregulation of the labor market. But extensive deindustrialization is probably also one of the drivers, that has led directly to the weakening of middle income groups