1,847 research outputs found
Models for the Clustering of Far-Infrared and Sub-millimetre selected Galaxies
We discuss and compare two alternative models for the two-point angular
correlation function of galaxies detected through the sub-millimetre emission
using the Herschel Space Observatory. The first, now-standard Halo Model, which
represents the angular correlations as arising from one-halo and two-halo
contributions, is flexible but complex and rather unwieldy. The second model is
based on a much simpler approach: we incorporate a fitting function method to
estimate the matter correlation function with approximate model of the bias
inferred from the estimated redshift distribution to find the galaxy angular
correlation function. We find that both models give a good account of the shape
of the correlation functions obtained from published preliminary studies of the
HerMES and H-ATLAS surveys performed using Herschel, and yield consistent
estimates of the minimum halo mass within which the sub-millimetre galaxies
must reside. We note also that both models predict an inflection in the
correlation function at intermediate angular scales, so the presence of the
feature in the measured correlation function does not unambiguously indicate
the presence of intra-halo correlations. The primary barrier to more detailed
interpretation of these clustering measurements lies in the substantial
uncertainty surrounding the redshift distribution of the sources.Comment: 5 pages, 6 figures, 1 table, accepted for publication in MNRA
Solution-processed CdS transistors with high electron mobility
Solution-processed CdS field effect transistors (FETs) and solar cells are demonstrated via spin-coating and thermal annealing of soluble cadmium thiolate compounds. The synthesis is carried out in one simple step using cadmium oxide and tertiary alkane thiols. The cadmium thiolates are soluble in organic solvents such as chloroform and may be spin-coated, like organic semiconductors, to form thin films. The cadmium thiolate films decompose rapidly at 300 ??C to yield semiconducting cadmium sulfide films. FETs are easily fabricated using these films and exhibit electron mobilities of up to 61 cm2 V -1 s-1, which compare favourably to FETs prepared from other solution-processed materials such as organic semiconductors, inorganic nanoparticles or chalcogenide films. Initial attempts to prepare hybrid bilayer solar cells were successfully realized by spin-coating a p-type semiconducting polymer layer on top of the n-type CdS film. These devices show significant photocurrent response from both the CdS and polymer layers, indicating that the CdS films are able to participate in photo-induced electron transfer from the polymer to the CdS layer as well as photo-induced hole transfer from CdS to the polymer layer.close2
Anisotropic thermodynamic and transport properties of single crystalline CaKFeAs
Single crystalline, single phase CaKFeAs has been grown out of a
high temperature, quaternary melt. Temperature dependent measurements of x-ray
diffraction, anisotropic electrical resistivity, elastoresistivity,
thermoelectric power, Hall effect, magnetization and specific heat, combined
with field dependent measurements of electrical resistivity and field and
pressure dependent measurements of magnetization indicate that
CaKFeAs is an ordered, stoichiometric, Fe-based superconductor with
a superconducting critical temperature, = 35.0 0.2 K. Other than
superconductivity, there is no indication of any other phase transition for 1.8
K 300 K. All of these thermodynamic and transport data reveal
striking similarities to that found for optimally- or slightly over-doped
(BaK)FeAs, suggesting that stoichiometric CaKFeAs
is intrinsically close to what is referred to as "optimal-doped" on a
generalized, Fe-based superconductor, phase diagram. The anisotropic
superconducting upper critical field, , of
CaKFeAs was determined up to 630 kOe. The anisotropy parameter
, for applied
perpendicular and parallel to the c-axis, decreases from at
to at 25 K which can be explained by interplay of paramagnetic
pairbreaking and orbital effects. The slopes of
kOe/K and kOe/K at yield an electron mass anisotropy of
and short Ginzburg-Landau coherence lengths
and .
The value of can be extrapolated to
kOe, well above the BCS paramagnetic limit.Comment: 13 pages, 15 figures, part of arXiv:1606.02241 is include
Microstructure and Mechanical Properties of Heterogeneous Ceramic-Polymer Composite Using Interpenetrating Network
Prepolymer, which can be polymerized by a photo, has been infiltrated into a porous
ceramic to improve the addition effect of polymer into the ceramic, as a function of the
functionality of prepolymer. It induces the increase in the mechanical properties of the
ceramic. The porous alumina (Al2O3) and the polyurethane acrylate (PUA)
with a network structure by photo-polymerization were used as the matrix and
infiltration materials, respectively. The porous Al2O3 matrix without the polymer shows lower values in fracture strength than the composites, since the stress is transmitted more quickly via
propagation of cracks from intrinsic defects in the porous matrix. However, in the case
of composites, the distribution of stress between heterophases results in the improved
mechanical properties. In addition, the mechanical properties of composites, such as
elastic modulus and fracture strength, are enhanced with increasing the functionality of
prepolymer attributed to the crosslinking density of polymer
High mobility solution-processed hybrid light emitting transistors
We report the design, fabrication, and characterization of high-performance, solution-processed hybrid (inorganic-organic) light emitting transistors (HLETs). The devices employ a high-mobility, solution-processed cadmium sulfide layer as the switching and transport layer, with a conjugated polymer Super Yellow as an emissive material in non-planar source/drain transistor geometry. We demonstrate HLETs with electron mobilities of up to 19.5 cm2/V s, current on/off ratios of >107, and external quantum efficiency of 10-2% at 2100 cd/m2. These combined optical and electrical performance exceed those reported to date for HLETs. Furthermore, we provide full analysis of charge injection, charge transport, and recombination mechanism of the HLETs. The high brightness coupled with a high on/off ratio and low-cost solution processing makes this type of hybrid device attractive from a manufacturing perspective.open0
Seasonality and the microhabitat of Microcotyle sebastis Goto, 1894, a monogenean gill parasite of farmed rockfish, Sebastes schlegeli Hilgendorf 1880
A total of 353 farmed rockfish, Sebastes schlegeli Hilgendorf, 1880 were sampled from 3 localities on the Korean coastline over a 12 month period. Full parasitological examination revealed the polyopisthocotylean monogenean Microcotyle sebastis Goto, 1894 to be abundant with infections consistently reaching over 90~100% prevalence throughout the year. A seasonal pattern in parasite abundance on the gills is evident, with the population peaking twice, the largest in winter and again in summer. While the parasitic load on the left and right gills was not dissimilar, parasites within the gill sets were found to favour settlement on the Ⅱ and Ⅲ gill arches. A comparison of parasite abundance with host length, revealed that the smaller length fish classes (less than 17 ㎝ standard body length) had significantly heavier infections than those of larger fish (greater than 17 ㎝ standard body length). This report represents the first record of Microcotyle sebastis on farmed rockfish in Korean coastal waters
Observation of Supercurrent in PbIn-Graphene-PbIn Josephson Junction
Superconductor-graphene-superconductor (SGS) junction provides a unique
platform to study relativistic electrodynamics of Dirac fermions combined with
proximity-induced superconductivity. We report observation of the Josephson
effect in proximity-coupled superconducting junctions of graphene in contact
with Pb1-xInx (x=0.07) electrodes for temperatures as high as T = 4.8K, with a
large IcRn (~ 255 microV). This demonstrates that Pb1-xInx SGS junction would
facilitate the development of the superconducting quantum information devices
and superconductor-enhanced phase-coherent transport of graphene.Comment: 8 pages, 7 figures, accepted in PR
Acute Cerebral Infarction Following Intravenous Glycoprotein IIb/IIIa Inhibitor for Acute Myocardial Infarction
Stroke is a rare but serious complication of acute myocardial infarction (AMI). Currently, glycoprotein (GP) IIb/IIIa inhibitor is used in clinical practice for acute coronary syndromes and percutaneous coronary interventions (PCIs). The incidence of stroke in patients receiving GP IIb/IIIa inhibitor during PCIs is very low. We report the case of a 47-year-old man who presented with AMI and suffered an acute cerebral infarction after infusion of a GP IIb/IIIa inhibitor following primary PCI
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Highly-Sensitive Textile Pressure Sensors Enabled by Suspended-Type All Carbon Nanotube Fiber Transistor Architecture.
Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa-1 and a response/recovery time of 258/114 ms in the very low-pressure range of <300 Pa as the fiber transistor was operated in the linear region (VDS = -0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS
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