Simulation of an ion thruster control system

The results of an initial effort to model the control loops of a 30-cm diameter electron bombardment thruster and a transistorized power processor predicting its operation were described. Data from which the model is made is presented as well as comparisons between the computer outputs and test data from the JPL Solar Electric Propulsion systems laboratory

Plume Characterization of a One-Millipound Solid Teflon Pulsed Plasma Thruster, Phase 2

Measurements of the pulsed plasma thruster (PPT) plume upstream mass flux were made in the Molecular Sink (MOLSINK) vacuum facility in order to minimize the plume-tank wall reflected mass flux. Using specially designed collimators on 4 rows of Quartz Crystal Microbalanced (QCMs) mounted on a support extending radially away from the plume axis, measurements were made of the mass flux originating in a thin slice of the PPT primary plume at an arbitrary dip angle with respect to the thruster axis. The measured and analytically corrected mass flux from particles reflected from the MOLSINK walls was substracted from the collimated QCM measurements to improve their accuracy. These data were then analytically summed over dip angle to estimate the total plume backflow upstream of the thruster nozzle. The results indicate that the PPT backflow is of order 10 to the minus 10th power g/square cm/pulse in the region from 38 to 86 cm from the PPT axis in the nozzle exit plane. This flux drops with the square of the radial distance from the PPT axis and is comparable to the backflow of an 8 cm ion thruster, which has performance characteristics similar to those of the PPT

Selecting a Control Strategy for Plug and Process Loads

Plug and Process Loads (PPLs) are building loads that are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the building occupants. PPLs in commercial buildings account for almost 5% of U.S. primary energy consumption. On an individual building level, they account for approximately 25% of the total electrical load in a minimally code-compliant commercial building, and can exceed 50% in an ultra-high efficiency building such as the National Renewable Energy Laboratory's (NREL) Research Support Facility (RSF) (Lobato et al. 2010). Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. A complex array of technologies that measure and manage PPLs has emerged in the marketplace. Some fall short of manufacturer performance claims, however. NREL has been actively engaged in developing an evaluation and selection process for PPLs control, and is using this process to evaluate a range of technologies for active PPLs management that will cap RSF plug loads. Using a control strategy to match plug load use to users' required job functions is a huge untapped potential for energy savings

Multicenter phase II trial of gefitinib first-line therapy followed by chemotherapy in advanced non-small-cell lung cancer (NSCLC): SAKK protocol 19/03

Background: Gefitinib is active in patients with pretreated non-small-cell lung cancer (NSCLC). We evaluated the activity and toxicity of gefitinib first-line treatment in advanced NSCLC followed by chemotherapy at disease progression. Patients and methods: In all, 63 patients with chemotherapy-naive stage IIIB/IV NSCLC received gefitinib 250 mg/day. At disease progression, gefitinib was replaced by cisplatin 80 mg/m2 on day 1 and gemcitabine 1250 mg/m2 on days 1, 8 for up to six 3-week cycles. Primary end point was the disease stabilization rate (DSR) after 12 weeks of gefitinib. Results: After 12 weeks of gefitinib, the DSR was 24% and the response rate (RR) was 8%. Median time to progression (TtP) was 2.5 months and median overall survival (OS) 11.5 months. Never smokers (n = 9) had a DSR of 56% and a median OS of 20.2 months; patients with epidermal growth factor receptor (EGFR) mutation (n = 4) had a DSR of 75% and the median OS was not reached after the follow-up of 21.6 months. In all, 41 patients received chemotherapy with an overall RR of 34%, DSR of 71% and median TtP of 6.7 months. Conclusions: First-line gefitinib monotherapy led to a DSR of 24% at 12 weeks in an unselected patients population. Never smokers and patients with EGFR mutations tend to have a better outcome; hence, further trials in selected patients are warrante

Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector

We present an update of our previous study (astro-ph/0112312) on how $\nu$ oscillations affect the signal from a supernova core collapse observed in the LVD detector at LNGS. In this paper we use a recent, more precise determination of the cross section (astro-ph/0302055) to calculate the expected number of inverse beta decay events, we introduce in the simulation also the $\nu$-{\rm Fe} interactions, we include the Earth matter effects and, finally, we study also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200

The relative orientation of the TM3 and TM4 domains varies between α1 and α3 glycine receptors

Glycine receptors (GlyRs) are anion-conducting members of the pentameric ligand-gated ion channel family. We previously showed that the dramatic difference in glycine efficacies of α1 and α3 GlyRs is largely attributable to their nonconserved TM4 domains. Because mutation of individual nonconserved TM4 residues had little effect, we concluded that the efficacy difference was a distributed effect of all nonconserved TM4 residues. We therefore hypothesized that the TM4 domains of α1 and α3 GlyRs differ in structure, membrane orientation, and/or molecular dynamic properties. Here we employed voltage-clamp fluorometry to test whether their TM4 domains interact differently with their respective TM3 domains. We found a rhodamine fluorophore covalently attached to a homologous TM4 residue in each receptor interacts differentially with a conserved TM3 residue. We conclude that the α1 and α3 GlyR TM4 domains are orientated differently relative to their TM3 domains. This may underlie their differential ability to influence glycine efficacy

Search for low energy neutrinos in correlation with the 8 events observed by the EXPLORER and NAUTILUS detectors in 2001

We report on a search for low-energy neutrino (antineutrino) bursts in correlation with the 8 time coincident events observed by the gravitational waves detectors EXPLORER and NAUTILUS (GWD) during the year 2001. The search, conducted with the LVD detector (INFN Gran Sasso National Laboratory, Italy), has considered several neutrino reactions, corresponding to different neutrino species, and a wide range of time intervals around the (GWD) observed events. No evidence for statistically significant correlated signals in LVD has been found. Assuming two different origins for neutrino emission, the cooling of a neutron star from a core-collapse supernova or from coalescing neutron stars and the accretion of shocked matter, and taking into account neutrino oscillations, we derive limits to the total energy emitted in neutrinos and to the amount of accreting mass, respectively.Comment: Accepted for publication in Astronomy and Astrophysic

First CNGS events detected by LVD

The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band $\nu_{\mu}$ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the $\nu_{\tau}$ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of $7.6~10^{17}$ protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.Comment: Accepted for publication by the European Physical Journal C ; 7 pages, 11 figure