National Space Science Data Center data archive and distribution service (NDADS) automated retrieval mail system user's guide

The National Space Science Data Center (NSSDC) has developed an automated data retrieval request service utilizing our Data Archive and Distribution Service (NDADS) computer system. NDADS currently has selected project data written to optical disk platters with the disks residing in a robotic 'jukebox' near-line environment. This allows for rapid and automated access to the data with no staff intervention required. There are also automated help information and user services available that can be accessed. The request system permits an average-size data request to be completed within minutes of the request being sent to NSSDC. A mail message, in the format described in this document, retrieves the data and can send it to a remote site. Also listed in this document are the data currently available

Hydrothermal synthesis of nanosized BaTiO3 powders and dielectric properties of corresponding ceramics

BaTiO3 fine powders were synthesized by hydrothermal method at 150 °C or 250 °C for 7 h, starting from a mixture of TiCl3 + BaCl2 or TiO2 + BaCl2. The size of the crystallites is close to 20 nm whatever the starting mixture and the reaction temperature. These powders are well crystallized and constituted of a mixture of the metastable cubic and stable tetragonal phases. The ceramics obtained after uniaxial pressing and sintering at 1250 °C for 10 h or 20 h present high densification (up to 99.8%). The Curie temperature (Tc) and the electrical permittivity ( r) of the ceramics strongly depend on the type of titanium source that has been used for preparing the powder and on the sintering dwell time. Particularly, Tc is shifted towards lower temperature when TiCl3 is used. The permittivity value at Tc of BaTiO3 sintered at 1250 °C for 10 h reaches 7000 and 11,000 with respectively TiCl3 and TiO2 used as titanium source

Stabilization of metal ensembles at room temperature. Palladium clusters in zeolites

Palladium clusters of low nuclearity have been prepared in the cavities of X zeolites via ion exchange with Pd(NH,),Cl,, oxidative dehydration, and subsequent reduction of the dry Pd(I1) zeolites with hydrogen at 295 and 425 K. Detailed EXAFS analysis of Pd K-edge data shows that the average first-shell Pd-Pd coordination number of the reduced system is only about N = 1.5 at a distance of 2.78 A. A long, relatively disordered coordination of the reduced Pd to framework oxygen and silicon indicates the stabilizing, templating function of the zeolite matrix. Geometric models based upon the EXAFS results show that intrazeolite Pdz, Pd,, and Pd4 clusters are formed by partial occupation of SI and SII positions of the sodalite subunits of the zeolite. This study presents evidence for the formation of molecular metal ensembles stabilized in an open-framework matrix to at least 425 K

The Desktop Muon Detector: A simple, physics-motivated machine- and electronics-shop project for university students

This paper describes an undergraduate-level physics project that incorporates various aspects of machine- and electronics-shop technical development. The desktop muon detector is a self-contained apparatus that employs plastic scintillator as a detection medium and a silicon photomultiplier for light collection. These detectors can be used in conjunction with the provided software to make interesting physics measurements. The total cost of each counter is approximately $100.Comment: 29 pages, 14 figure

Adjusting DICOM specifications when using wireless LANs: The MedLAN example

Wireless networks will become increasingly useful in point-of-care areas such as hospitals, because of their ease of use and their flexibility. A system called MedLAN has been developed by the Central Middlesex Hospital and Brunei University to take advantage of the above desirable properties of WLANs for use in accident & emergency departments to broadcast live, high quality video images and sound over a LAN or the Internet. However, in many cases, the limited available throughput of such a WLAN system makes the use of high demanding specifications, such as DICOM, problematic especially when using no compression during transmission. In this paper we will present some practical results when combining low compression with wireless LANs. We will conclude with the assessment of images and sounds by several doctors showing that the system we have devised is very useful in this setting

The Laser of the ALICE Time Projection Chamber

The large TPC ($95 \mathrm{m}^3$) of the ALICE detector at the CERN LHC was commissioned in summer 2006. The first tracks were observed both from the cosmic ray muons and from the laser rays injected into the TPC. In this article the basic principles of operating the $266 \mathrm{nm}$ lasers are presented, showing the installation and adjustment of the optical system and describing the control system. To generate the laser tracks, a wide laser beam is split into several hundred narrow beams by fixed micro-mirrors at stable and known positions throughout the TPC. In the drift volume, these narrow beams generate straight tracks at many angles. Here we describe the generation of the first tracks and compare them with simulations.Comment: QM06 poster proceedings, 6 pages, 4 figure

Effects of different needles and substrates on CuInS2 deposited by electrostatic spray deposition

Copper indium disulphide (CuInS2) thin films were deposited using the electrostatic spray deposition method. The effects of applied voltage and solution flow rate on the aerosol cone shape, film composition, surface morphology and current conversion were investigated. The effect of aluminium substrates and transparent fluorine doped tin oxide (SnO2:F) coated glass substrates on the properties of as-deposited CuInS2 films were analysed. An oxidation process occurs during the deposition onto the metallic substrates which forms an insulating layer between the photoactive film and substrate. The effects of two different spray needles on the properties of the as-deposited films were also studied. The results reveal that the use of a stainless steel needle results in contamination of the film due to the transfer of metal impurities through the spray whilst this is not seen for the glass needle. The films were characterised using a number of different analytical techniques such as X-ray diffraction, scanning electron microscopy, Rutherford back-scattering and secondary ion mass spectroscopy and opto-electronic measurements

Ferromagnetic behavior of ultrathin manganese nanosheets

Ferromagnetic behaviour has been observed experimentally for the first time in nanostructured Manganese. Ultrathin ($\sim$ 0.6 nm) Manganese nanosheets have been synthesized inside the two dimensional channels of sol-gel derived Na-4 mica. The magnetic properties of the confined system are measured within 2K-300K temperature range. The confined structure is found to show a ferromagnetic behaviour with a nonzero coercivity value. The coercivity value remains positive throughout the entire temperature range of measurement. The experimental variation of susceptibility as a function of temperature has been satisfactorily explained on the basis of a two dimensional system with a Heisenberg Hamiltonian involving direct exchange interaction.Comment: 13 pages, 9 figure

Goddard Robotic Telescope - Optical Follow-up of GRBs and Coordinated Observations of AGNs -

Since it is not possible to predict when a Gamma-Ray Burst (GRB) will occur or when Active Galactic Nucleus (AGN) flaring activity starts, follow-up/monitoring ground telescopes must be located as uniformly as possible all over the world in order to collect data simultaneously with Fermi and Swift detections. However, there is a distinct gap in follow-up coverage of telescopes in the eastern U.S. region based on the operations of Swift. Motivated by this fact, we have constructed a 14" fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are 1) to follow-up Swift/Fermi GRBs and 2) to perform the coordinated optical observations of Fermi Large Area Telescope (LAT) AGN. Our telescope system consists of off-the-shelf hardware. With the focal reducer, we are able to match the field of view of Swift narrow instruments (20' x 20'). We started scientific observations in mid-November 2008 and GRT has been fully remotely operated since August 2009. The 3 sigma upper limit in a 30-second exposure in the R filter is ~15.4 mag; however, we can reach to ~18 mag in a 600-second exposures. Due to the weather condition at the telescope site, our observing efficiency is 30-40% on average.Comment: 14 pages, 14 figures, accepted for publication in ASR special issue on Neutron Stars and Gamma Ray Burst