Cowbane, Oxypolis occidentalis, A New Native Vascular Plant Species for the Queen Charlotte Islands, British Columbia

We report the recent discovery of Oxypolis occidentalis, a species that is new to both British Columbia and Canada, disjunct on the Queen Charlotte Islands

VLA Observations of Ultraluminous IRAS Galaxies: Active Nuclei or Starbursts?

We employed the Very Large Array (VLA) of the National Radio Astronomy Observatory in C configuration to map 39 ultraluminous IRAS galaxies at 6~cm and 20~cm, at resolutions of ~ 4" and 15", respectively, and 24 sources at 6~cm with in the A configuration with a resolution of ~0.5". Most of the sources have radio spectral indices indicative of synchrotron emission (alpha ~ -0.65). There is one source, however, that shows an inverted spectrum with alpha = +2.1; observations at higher frequencies show that the spectrum peaks between 5 and 8 GHz, as high as any of the ``gigahertz peaked spectrum'' sources studied by O'Dea etal. We discuss the implications of this source for observations of fluctuations in the CMB. Two of the sources show multiple unresolved components, another four are doubles with at least one resolved component, 14 show extended emission which could arise from a disk, and two show arc-second long jets. Our data fit the tight correlation found by Helou etal (1985) between far-infrared and microwave luminosity; this correlation extends to the highest infrared luminosities. The correlation is weaker if only the extended or the nuclear components of the radio luminosity are used. Therefore the far-infrared emission in the majority of these higher luminosity galaxies is due to the same mechanism as the lower luminosity FIR sources, which is believed to be star formation, rather than non-thermal activity in the nucleus. Moreover, the star formation is not confined to the extended disk in these sources, but is important in the nucleus as well.Comment: In press, Astrophysical Journal. 34 pages, uuencoded gzip'ed postscript of text, tables and figures. 3 figures not included; contact Margaret Best at [email protected] for hardcopies of thes

Tracking and Data Relay Satellite System (TDRSS) Support of User Spacecraft without TDRSS Transponders

NASA GSFC VNS TSG personnel have proposed the use of TDRSS to obtain telemetry and/or S-band one-way return Doppler tracking data for spacecraft which do not have TDRSS-compatible transponders and therefore were never considered candidates for TDRSS support. For spacecraft with less stable local oscillators (LO), one-way return Doppler tracking data is typically of poor quality. It has been demonstrated using UARS, WIND, and NOAA-J tracking data that the simultaneous use of two TDRSS spacecraft can yield differenced one-way return Doppler data of high quality which is usable for orbit determination by differencing away the effects of oscillator instability

Surging Versus Continuous Turbidity Currents: Flow Dynamics and Deposits in an Experimental Intraslope Minibasin

Small intraslope basins (~100 km^2), or "minibasins," such as those found on the continental slope of the Gulf of Mexico, have been filled predominantly by turbidity currents. Each minibasin is the result of local subsidence and is partially or completely isolated from neighboring basins by ridges formed from compensational uplift. We undertook a series of experiments to investigate the relationship between the flow dynamics of turbidity currents entering a minibasin and the stratal architecture of their deposits. The experiments were performed using continuous-feed turbidity currents and surge-feed turbidity currents. A dimensionless ponding number is developed to compare the geometry of the deposits with the dynamics of the flows that filled the basins. The experimental surging turbidity currents created a deposit that was notably more ponded than the deposits of continuous turbidity currents

Intermediate Language Design of High-level Language Virtual Machines: Towards Comprehensive Concurrency Support

Today's major high-level language virtual machines (VMs) are becoming successful in being multi-language execution platforms, hosting a wide range of languages. With the transition from few-core to many-core processors, we argue that VMs will also have to abstract from concrete concurrency models at the hardware level, to be able to support a wide range of abstract concurrency models on a language level. To overcome the lack of sufficient abstractions for concurrency concepts in VMs, we proposed earlier to extend VM intermediate languages by special concurrency constructs. As a first step towards this goal, we try to fill a gap in the current literature and survey the intermediate language design of VMs. Our goal is to identify currently used techniques and principles as well as to gain an overview over the available concurrency related features in intermediate languages. Another aspect of interest is the influence of the particular target language, for which the VM is originally intended, on the intermediate language

CSOM/PL: A Virtual Machine Product Line

CSOM/PL is a software product line (SPL) derived from applying multi-dimensional separation of concerns (MDSOC) techniques to the domain of high-level language virtual machine (VM) implementations. For CSOM/PL, we modularised CSOM, a Smalltalk VM implemented in C, using VMADL (virtual machine architecture description language). Several features of the original CSOM were encapsulated in VMADL modules and composed in various combinations. In an evaluation of our approach, we show that applying MDSOC and SPL principles to a domain as complex as that of VMs is not only feasible but beneficial, as it improves understandability, maintainability, and configurability of VM implementations without harming performance

Separation and identification of dominant mechanisms in double photoionization

Double photoionization by a single photon is often discussed in terms of two contributing mechanisms, {\it knock-out} (two-step-one) and {\it shake-off} with the latter being a pure quantum effect. It is shown that a quasi-classical description of knock-out and a simple quantum calculation of shake-off provides a clear separation of the mechanisms and facilitates their calculation considerably. The relevance of each mechanism at different photon energies is quantified for helium. Photoionization ratios, integral and singly differential cross sections obtained by us are in excellent agreement with benchmark experimental data and recent theoretical results.Comment: 4 pages, 5 figure

Dosimeter-Type NOx Sensing Properties of KMnO4 and Its Electrical Conductivity during Temperature Programmed Desorption

An impedimetric NOx dosimeter based on the NOx sorption material KMnO4 is proposed. In addition to its application as a low level NOx dosimeter, KMnO4 shows potential as a precious metal free lean NOx trap material (LNT) for NOx storage catalysts (NSC) enabling electrical in-situ diagnostics. With this dosimeter, low levels of NO and NO2 exposure can be detected electrically as instantaneous values at 380 °C by progressive NOx accumulation in the KMnO4 based sensitive layer. The linear NOx sensing characteristics are recovered periodically by heating to 650 °C or switching to rich atmospheres. Further insight into the NOx sorption-dependent conductivity of the KMnO4-based material is obtained by the novel eTPD method that combines electrical characterization with classical temperature programmed desorption (TPD). The NOx loading amount increases proportionally to the NOx exposure time at sorption temperature. The cumulated NOx exposure, as well as the corresponding NOx loading state, can be detected linearly by electrical means in two modes: (1) time-continuously during the sorption interval including NOx concentration information from the signal derivative or (2) during the short-term thermal NOx release