The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun’s surface. ISIS ...comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins—defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration—determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport—revealing how energetic particles propagate from the corona out into the heliosphere. The two ISIS Energetic Particle Instruments measure lower (EPI-Lo) and higher (EPI-Hi) energy particles. EPI-Lo measures ions and ion composition from ∼20 keV/nucleon–15 MeV total energy and electrons from ∼25–1000 keV. EPI-Hi measures ions from ∼1–200 MeV/nucleon and electrons from ∼0.5–6 MeV. EPI-Lo comprises 80 tiny apertures with fields-of-view (FOVs) that sample over nearly a complete hemisphere, while EPI-Hi combines three telescopes that together provide five large-FOV apertures. ISIS observes continuously inside of 0.25 AU with a high data collection rate and burst data (EPI-Lo) coordinated with the rest of the SPP payload; outside of 0.25 AU, ISIS runs in low-rate science mode whenever feasible to capture as complete a record as possible of the solar energetic particle environment and provide calibration and continuity for measurements closer in to the Sun. The ISIS Science Operations Center plans and executes commanding, receives and analyzes all ISIS data, and coordinates science observations and analyses with the rest of the SPP science investigations. Together, ISIS’ unique observations on SPP will enable the discovery, untangling, and understanding of the important physical processes that govern energetic particles in the innermost regions of our heliosphere, for the first time. This paper summarizes the ISIS investigation at the time of the SPP mission Preliminary Design Review in January 2014.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We have developed a novel protein chip technology that allows the high-throughput analysis of biochemical activities, and used this approach to analyse nearly all of the protein kinases from ...Saccharomyces cerevisiae. Protein chips are disposable arrays of microwells in silicone elastomer sheets placed on top of microscope slides. The high density and small size of the wells allows for high-throughput batch processing and simultaneous analysis of many individual samples. Only small amounts of protein are required. Of 122 known and predicted yeast protein kinases, 119 were overexpressed and analysed using 17 different substrates and protein chips. We found many novel activities and that a large number of protein kinases are capable of phosphorylating tyrosine. The tyrosine phosphorylating enzymes often share common amino acid residues that lie near the catalytic region. Thus, our study identified a number of novel features of protein kinases and demonstrates that protein chip technology is useful for high-throughput screening of protein biochemical activity.
Full text
Available for:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Low-Energy Telescope (LET) is one of four sensors that make up the Solar Energetic Particle (SEP) instrument of the IMPACT investigation for NASA’s STEREO mission. The LET is designed to measure ...the elemental composition, energy spectra, angular distributions, and arrival times of H to Ni ions over the energy range from ∼3 to ∼30 MeV/nucleon. It will also identify the rare isotope
3
He and trans-iron nuclei with 30≤
Z
≤83. The SEP measurements from the two STEREO spacecraft will be combined with data from ACE and other 1-AU spacecraft to provide multipoint investigations of the energetic particles that result from interplanetary shocks driven by coronal mass ejections (CMEs) and from solar flare events. The multipoint in situ observations of SEPs and solar-wind plasma will complement STEREO images of CMEs in order to investigate their role in space weather. Each LET instrument includes a sensor system made up of an array of 14 solid-state detectors composed of 54 segments that are individually analyzed by custom Pulse Height Analysis System Integrated Circuits (PHASICs). The signals from four PHASIC chips in each LET are used by a Minimal Instruction Set Computer (MISC) to provide onboard particle identification of a dozen species in ∼12 energy intervals at event rates of ∼1,000 events/sec. An additional control unit, called SEP Central, gathers data from the four SEP sensors, controls the SEP bias supply, and manages the interfaces to the sensors and the SEP interface to the Instrument Data Processing Unit (IDPU). This article outlines the scientific objectives that LET will address, describes the design and operation of LET and the SEP Central electronics, and discusses the data products that will result.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this paper a statistically significant study of 1096 individual GaN nanowire (NW) devices is presented. We have correlated the effects of changing growth parameters for hot-wall ...chemically-vapour-deposited (HW-CVD) NWs fabricated via the vapour-liquid-solid mechanism. We first describe an optical lithographic method for creating Ohmic contacts to NW field effect transistors with both top and bottom electrostatic gates to characterize carrier density and mobility. Multiprobe measurements show that carrier modulation occurs in the channel and is not a contact effect. We then show that NW fabrication runs with nominally identical growth parameters yield similar electrical results across sample populations of > 50 devices. By systematically altering the growth parameters we were able to decrease the average carrier concentration for these as-grown GaN NWs X10-fold, from 2.29 x 1020 to 2.45 x 1019 cm-3, and successfully elucidate the parameters that exert the strongest influence on wire quality. Furthermore, this study shows that nitrogen vacancies, and not oxygen impurities, are the dominant intrinsic dopant in HW-CVD GaN NWs.
Molecular Wires, Switches, and Memories CHEN, J.; WANG, W.; KLEMIC, J. ...
Annals of the New York Academy of Sciences,
April 2002, Volume:
960, Issue:
1
Journal Article
Peer reviewed
: Design and measurements of molecular wires, switches, and memories offer an increased device capability with reduced elements. We report: Measurements on through‐bond electronic transport ...properties of nanoscale metal‐1,4‐phenylene diisocyanide‐metal junctions are reported, where nonohmic thermionic emission is the dominant process, with isocyanide‐Pd showing the lowest thermionic barrier of 0.22 eV; robust and large reversible switching behavior in an electronic device that utilizes molecules containing redox centers as the active component, exhibiting negative differential resistance (NDR) and large on‐off peak‐to‐valley ratio (PVR) are realized; erasable storage of higher conductivity states in these redox‐center‐containing molecular devices are observed; and a two‐terminal electronically programmable and erasable molecular memory cell with long bit retention time is demonstrated.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
6.
Hotwiring biosensors Klemic, James F; Stern, Eric; Reed, Mark A
Nature biotechnology,
10/2001, Volume:
19, Issue:
10
Journal Article
Peer reviewed
Nanowire sensors decorated with specific capture molecules can detect minute quantities of biological and chemical species. Imagine a microchip biosensor with an enormous number of highly specific ...and sensitive antibody/antigen assay reactions, interfaced to the fast parallel electronic signal processing capability of an integrated circuit (IC). Recent developments suggest that such a device may eventually be realized. In a recent issue of Science, Cui et al. report the conductance behavior of nanofabricated doped silicon wires functionalized with organic molecules and biomolecules. Results indicate these functionalized nanowires may provide a new type of platform for sensitive and selective chemical and biological sensors. What is particularly exciting about these results is the potential for realizing a nanoscale interface that bridges solid-state electronics and true molecular-scale processes, not only for detection and selectivity but also for eventual use in extra- and intercellular measurements.
Full text
Available for:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The SuperTIGER (Super Trans-Iron Galactic Element Recorder) instrument was developed to measure the abundances of galactic cosmic-ray elements from sub(10)Ne to sub(40)Zr with individual element ...resolution and the high statistics needed to test models of cosmic-ray origins. SuperTIGER also makes exploratory measurements of the abundances of elements with 40 < Z < or =, slant 60 and measures the energy spectra of the more abundant elements for Z < or =, slant 30 from about 0.8 to 10 GeV/nucleon. This instrument is an enlarged and higher resolution version of the earlier TIGER instrument. It was designed to provide the largest geometric acceptance possible and to reach as high an altitude as possible, flying on a standard long-duration 1.11 million m super(3) balloon. SuperTIGER was launched from Williams Field, McMurdo Station, Antarctica, on 2012 December 8, and made about 2.7 revolutions around the South Pole in 55 days of flight, returning data on over 50 x 10 super(6) cosmic-ray nuclei with Z > or =, slanted 10, including ~1300 with Z > 29 and ~60 with Z > 49. Here, we describe the instrument, the methods of charge identification employed, the SuperTIGER balloon flight, and the instrument performance.
The patch clamp method measures membrane currents at very high resolution when a high-resistance ‘gigaseal’ is established between the glass microelectrode and the cell membrane (Pflugers Arch. 391 ...(1981) 85; Neuron 8 (1992) 605). Here we describe the first use of the silicone elastomer, poly(dimethylsiloxane) (PDMS), for patch clamp electrodes. PDMS is an attractive material for patch clamp recordings. It has low dielectric loss and can be micromolded (Annu. Rev. Mat. Sci. 28 (1998) 153) into a shape that mimics the tip of the glass micropipette. Also, the surface chemistry of PDMS may be altered to mimic the hydrophilic nature of glass (J. Appl. Polym. Sci. 14 (1970) 2499; Annu. Rev. Mat. Sci. 28 (1998) 153), thereby allowing a high-resistance seal to a cell membrane. We present a planar electrode geometry consisting of a PDMS partition with a small aperture sealed between electrode and bath chambers. We demonstrate that a planar PDMS patch electrode, after oxidation of the elastomeric surface, permits patch clamp recording on
Xenopus oocytes. Our results indicate the potential for high-throughput patch clamp recording with a planar array of PDMS electrodes.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Room-temperature charge transport is investigated for various-length alkanethiol self-assembled monolayers using three different characterization methods, in which lateral areas span from the ...nanometer to the micrometer scale. In each method, the measured current−voltage characteristics are analyzed with metal−insulator−metal tunneling models. Transport parameters are determined where possible and compared across methods, as well as to previously reported values. Advantages and limitations of each method for characterizing molecular junctions are highlighted.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
We present a new technique for fabricating planar patch electrodes in the laboratory. Planar electrodes are micromolded using a micron-sized stream of air to define an aperture in the silicone ...elastomer, polydimethylsiloxane (PDMS). We have previously demonstrated that planar PDMS electrodes make excellent patch electrodes after surface modification. We demonstrate single-channel measurements of the rSlo channel in Xenopus oocytes and whole-cell measurements in CHO and RBL mammalian cell lines, using planar PDMS electrodes.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
