677 research outputs found
On some batch code properties of the simplex code
The binary -dimensional simplex code is known to be a -batch code
and is conjectured to be a -functional batch code. Here, we offer a
simple, constructive proof of a result that is "in between" these two
properties. Our approach is to relate these properties to certain (old and new)
additive problems in finite abelian groups. We also formulate a conjecture for
finite abelian groups that generalizes the above-mentioned conjecture
Multichannel Time Synchronization Based on PTP through a High Voltage Isolation Buffer Network Interface for Thick-GEM Detectors
Data logging and complex algorithm implementations acting on multichannel systems with independent devices require the use of time synchronization. In the case of Gas Electron Multipliers (GEM) and Thick-GEM (THGEM) detectors, the biasing potential can be generated at the detector level via DC to DC converters operating at floating voltage. In this case, high voltage isolation buffers may be used to allow communication between the different channels. However, their use add non-negligible delays in the transmission channel, complicating the synchronization. Implementation of a simplified precise time protocol is presented for handling the synchronization on the Field Programmable Gate Array (FPGA) side of a Xilinx SoC Zynq ZC7Z030. The synchronization is done through a high voltage isolated bidirectional network interface built on a custom board attached to a commercial CIAA_ACC carrier. The results of the synchronization are shown through oscilloscope captures measuring the time drift over long periods of time, achieving synchronization in the order of nanoseconds
Radius and chirality dependent conformation of polymer molecule at nanotube interface
Temperature dependent conformations of linear polymer molecules adsorbed at
carbon nanotube (CNT) interfaces are investigated through molecule dynamics
simulations. Model polyethylene (PE) molecules are shown to have selective
conformations on CNT surface, controlled by atomic structures of CNT lattice
and geometric coiling energy. PE molecules form entropy driven assembly
domains, and their preferred wrapping angles around large radius CNT (40, 40)
reflect the molecule configurations with energy minimums on a graphite plane.
While PE molecules prefer wrapping on small radius armchair CNT (5, 5)
predominantly at low temperatures, their configurations are shifted to larger
wrapping angle ones on a similar radius zigzag CNT (10, 0). A nematic
transformation around 280 K is identified through Landau-deGennes theory, with
molecule aligning along tube axis in extended conformationsComment: 19 pages, 7 figure2, submitted to journa
KELT-8b: A highly inflated transiting hot Jupiter and a new technique for extracting high-precision radial velocities from noisy spectra
We announce the discovery of a highly inflated transiting hot Jupiter
discovered by the KELT-North survey. A global analysis including constraints
from isochrones indicates that the V = 10.8 host star (HD 343246) is a mildly
evolved, G dwarf with K, , , an inferred mass
M, and radius
R. The planetary companion has mass , radius
, surface gravity , and density
g cm. The planet is on a roughly
circular orbit with semimajor axis AU and
eccentricity . The best-fit linear ephemeris is
BJD and
days. This planet is one of the most inflated of all known transiting
exoplanets, making it one of the few members of a class of extremely low
density, highly-irradiated gas giants. The low stellar and large
implied radius are supported by stellar density constraints from follow-up
light curves, plus an evolutionary and space motion analysis. We also develop a
new technique to extract high precision radial velocities from noisy spectra
that reduces the observing time needed to confirm transiting planet candidates.
This planet boasts deep transits of a bright star, a large inferred atmospheric
scale height, and a high equilibrium temperature of
K, assuming zero albedo and perfect heat redistribution, making it one of the
best targets for future atmospheric characterization studies.Comment: Submitted to ApJ, feedback is welcom
Shared decision making in breast cancer treatment guidelines: Development of a quality assessment tool and a systematic review
Background: It is not clear whether clinical practice guidelines (CPGs) and consensus
statements (CSs) are adequately promoting shared decision making (SDM).
Objective: To evaluate the recommendations about SDM in CPGs and CSs concerning breast cancer (BC) treatment.
Search strategy: Following protocol registration (Prospero no.: CRD42018106643),
CPGs and CSs on BC treatment were identified, without language restrictions,
through systematic search of bibliographic databases (MEDLINE, EMBASE, Web of
Science, Scopus, CDSR) and online sources (12 guideline databases and 51 professional society websites) from January 2010 to December 2019.
Inclusion criteria: CPGs and CSs on BC treatment were selected whether published
in a journal or in an online document.
Data extraction and synthesis: A 31-item SDM quality assessment tool was developed and used to extract data in duplicate.
Main results: There were 167 relevant CPGs (139) and CSs (28); SDM was reported
in only 40% of the studies. SDM was reported more often in recent publications after
2015 (42/101 (41.6 %) vs 46/66 (69.7 %), P = .0003) but less often in medical journal
publications (44/101 (43.5 %) vs 17/66 (25.7 %), P = .009). In CPGs and CSs with
SDM, only 8/66 (12%) met one-fifth (6 of 31) of the quality items; only 14/66 (8%)
provided clear and precise SDM recommendations.
Discussion and conclusions: SDM descriptions and recommendations in CPGs and
CSs concerning BC treatment need improvement. SDM was more frequently reported in CPGs and CSs in recent years, but surprisingly it was less often covered in
medical journals, a feature that needs attention
Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC
We are developing gaseous photon detectors for Cherenkov imaging applications
in the experiments at the future Electron Ion Collider. CsI, converting photons
in the far ultraviolet range, is, so far, the only photoconverter compatible
with the operation of gaseous detectors. It is very delicate to handle due to
its hygroscopic nature: the absorbed water vapour decomposes the CsI molecule.
In addition, its quantum efficiency degrades under ion bombardment. These are
the key reasons to quest for novel, less delicate materials for photocathodes
adequate for gaseous photon detectors. Layers of hydrogenated nanodiamond
particles have recently been proposed as an alternative material and have shown
promising characteristics. The performance of nanodiamond photocathodes coupled
to thick GEM-based detectors is the object of our ongoing R\&D. The first phase
of these studies includes the characterization of thick GEM coated with
nanodiamond layers and the robustness of its photoconverting properties with
respect to the bombardment by ions from the multiplication process in the
gaseous detector. The approach is described in detail as well as all the
results obtained so far within these exploratory studies
Site-specific Forest-assembly of Single-Wall Carbon Nanotubes on Electron-beam Patterned SiOx/Si Substrates
Based on electron-beam direct writing on the SiOx/Si substrates, favorable
absorption sites for ferric cations (Fe3+ ions) were created on the surface
oxide layer. This allowed Fe3+-assisted self-assembled arrays of single-wall
carbon nanotube (SWNT) probes to be produced. Auger investigation indicated
that the incident energetic electrons depleted oxygen, creating more dangling
bonds around Si atoms at the surface of the SiOx layer. This resulted in a
distinct difference in the friction forces from unexposed regions as measured
by lateral force microscopy (LFM). Atomic force microscopy (AFM) affirmed that
the irradiated domains absorbed considerably more Fe3+ ions upon immersion into
pH 2.2 aqueous FeCl3 solution. This rendered a greater yield of FeO(OH)/FeOCl
precipitates, primarily FeO(OH), upon subsequent washing with lightly basic
dimethylformamide (DMF) solution. Such selective metalfunctionalization
established the basis for the subsequent patterned forest-assembly of SWNTs as
demonstrated by resonance Raman spectroscopy
<i>Spitzer</i> microlens measurement of a massive remnant in a well-separated binary
We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having M1 > 1.35 M⊙ (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star (NS) or black hole (BH). The system has a projected separation r⊥ = 6.1 ± 0.4 AU and lies in the Galactic bulge. These measurements are based on the "microlens parallax" effect, i.e., comparing the microlensing light curve as seen from Spitzer, which lay at 1.25 AU projected from Earth, to the light curves from four ground-based surveys, three in the optical and one in the near-infrared. Future adaptive optics imaging of the companion by 30 m class telescopes will yield a much more accurate measurement of the primary mass. This discovery both opens the path and defines the challenges to detecting and characterizing BHs and NSs in wide binaries, with either dark or luminous companions. In particular, we discuss lessons that can be applied to future Spitzer and Kepler K2 microlensing parallax observations
- …