2,103 research outputs found
UKIRT Widefield Infrared Survey for Fe+
The United Kingdom Infrared Telescope (UKIRT)Widefield Infrared Survey for Fe+ (UWIFE) is a 180 deg2 imaging survey of the first Galactic quadrant (7° < l < 62° |b| <1°.5) that uses a narrow-band filter centred on the [Fe II] 1.644-μm emission line. The [Fe II] 1.644-μm emission is a good tracer of dense, shock-excited gas, and the survey will probe violent environments around stars: star-forming regions, evolved stars, and supernova remnants, among others. The UWIFE survey is designed to complement the existing UKIRTW idefield Infrared Survey for H2 (UWISH2). The survey will also complement existing broad-band surveys. The observed images have a nominal 5Ï? detection limit of 18.7 mag for point sources, with a median seeing of 0.83 arcsec. For extended sources, we estimate a surface brightness limit of 8.1 Ã? 10-20 W m-2 arcsec-2. In this paper, we present an overview and some preliminary results of this survey. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Complex Organic Molecules in a Very Young Hot Corino, HOPS 373SW
We present the spectra of Complex Organic Molecules (COMs) detected in HOPS
373SW with the Atacama Large Millimeter/submillimeter Array (ALMA). HOPS 373SW,
which is a component of a protostellar binary with a separation of 1500 au, has
been discovered as a variable protostar by the JCMT Transient monitoring survey
with a modest ~30% brightness increase at submillimeter wavelengths. Our ALMA
Target of Opportunity (ToO) observation at ~345 GHz for HOPS 373SW revealed
extremely young chemical characteristics with strong deuteration of methanol.
The dust continuum opacity is very high toward the source center, obscuring
line emission from within 0.03 arcsec. The other binary component, HOPS 373NE,
was detected only in C17O in our observation, implying a cold and quiescent
environment. We compare the COMs abundances relative to CH3OH in HOPS 373SW
with those of V883 Ori, which is an eruptive disk object, as well as other hot
corinos, to demonstrate the chemical evolution from envelope to disk. High
abundances of singly, doubly, and triply deuterated methanol (CH2DOH, CHD2OH,
and CD3OH) and a low CH3CN abundance in HOPS 373SW compared to other hot
corinos suggest a very early evolutionary stage of HOPS 373SW in the hot corino
phase. Since the COMs detected in HOPS 373SW would have been sublimated very
recently from grain surfaces, HOPS 373SW is a promising place to study the
surface chemistry of COMs in the cold prestellar phase, before sublimation.Comment: Accepted for publication in Ap
Transparent actuator made with few layer graphene electrode and dielectric elastomer, for variable focus lens
A transparent dielectric elastomer actuator driven by few-layer-graphene (FLG) electrode was experimentally investigated. The electrodes were made of graphene, which was dispersed inN-methyl-pyrrolidone. The transparent actuator was fabricated from developed FLG electrodes.The FLG electrode with its sheet resistance of 0.45 kΩ/sq (80 nm thick) was implemented to mask silicone elastomer. The developed FLG-driven actuator exhibited an optical transparency of over 57% at a wavenumber of 600 nm and produced bending displacement performance ranging from 29 to 946 μm as functions of frequency and voltage. The focus variation was clearly demonstrated under actuation to study its application-feasibility in variable focus lens and various opto-electro-mechanical devices
Identification of Factors that Influence Conscious Sedation in Gastrointestinal Endoscopy
Although several studies examined factors that influence conscious sedation, investigation was limited into the gender and age. The aim of this prospective study is to identify the clinical variables of successful conscious sedation during gastrointestinal endoscopy. A total of 300 subjects who underwent gastrointestinal endoscopy were enrolled in a prospective fashion. They completed a questionnaire to assess height, weight, drinking, smoking, education level, recent medication, past medical history, previous experience of conscious sedation, preprocedural anxiety, and apprehension about the procedure. Efficacy of sedation and amnesia were evaluated by the subject and the endoscopist. Amnesic and sedative effects were proportionally related with age (p<0.0001). Preprocedural anxiety level was higher in women (p=0.0062), younger subjects (p=0.035), slender subjects (p=0.041), and in those without previous experience of conscious sedation (p=0.0034). This anxiety level was also related to increased pain (p=0.0026) and alertness (p=0.0003) during the procedure. Lower dose of midazolam is needed for sedation in older subjects. Subjects with a high level of preprocedural anxiety such as women, younger subjects, slender subjects, and those without previous experience of conscious sedation should be sedated with great caution because generally, they complain of much more severe pain and alertness during the procedure
Free Hand Pedicle Screw Placement in the Thoracic Spine without Any Radiographic Guidance : Technical Note, a Cadaveric Study
Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity
Thermal properties of a photon gas in photonic crystals
We investigated the thermal properties of a photon gas in photonic crystals. Since the density of photon states in photonic crystals is modified, thermal radiation of photonic crystals is suppressed inside forbidden gaps and the heat capacity of photon gas is more enhanced than T3 as temperature increases. The heat capacities of phonons in periodic elastic composites and magnons in periodic ferromagnetic composites are also enhanced at sufficiently low temperature
Massive-Star Forming Infrared Loop around the Crab-like Supernova Remnant G54.1+0.3: Post Main-Sequence Triggered Star Formation?
We report the discovery of a star-forming loop around the young, Crab-like
supernova remnant (SNR) G54.1+0.3 using the AKARI infrared satellite. The loop
consists of at least eleven young stellar objects (YSOs) embedded in a
ring-like diffuse emission of radius ~1'. The YSOs are bright in the
mid-infrared and are also visible in the Spitzer Space Telescope Galactic plane
survey images. Their Spitzer colors are similar to those of class II YSOs in
[3.6]-[5.8] but significantly redder in [8]-[24], i.e., 0<[3.6]-[5.8]<1.2 and
5<[8]-[24]<9. Most of them have near-infrared counterparts in the 2MASS JHKs
images, and some of them have an optical counterpart too. Their JHKs colors and
magnitudes indicate that the YSOs are massive (<= 10 Msun) pre-main-sequence
stars at the same distance to the SNR, i.e., 8 kpc, which supports the
association of the star-forming loop with the SNR. The dereddened spectral
energy distributions are similar to eraly Herbig Be stars, which are early
B-type pre-main-sequence stars with inner disks that have been destroyed. The
confinement to a loop structure indicates that the YSOs are young, i.e., <= 2
Myr. We propose that their formation is triggered by the progenitor star of
G54.1+0.3, which has a mass of <= 15 Msun. The triggering must have occurred
near the end of the progenitor's life, possibly after it had evolved off the
main sequence.Comment: 6 pages, accepted for publication in the Astrophysical Journal
Letters; added a reference for section
Assessment of Microwave/UV/O3 in the Photo-Catalytic Degradation of Bromothymol Blue in Aqueous Nano TiO2 Particles Dispersions
In this study, a microwave/UV/TiO2/ozone/H2O2 hybrid process system, in which various techniques that have been used for water treatment are combined, is evaluated to develop an advanced technology to treat non-biodegradable water pollutants efficiently. In particular, the objective of this study is to develop a novel advanced oxidation process that overcomes the limitations of existing single-process water treatment methods by adding microwave irradiation to maximize the formation of active intermediate products, e.g., OH radicals, with the aid of UV irradiation by microwave discharge electrodeless lamp, photo-catalysts, and auxiliary oxidants. The results of photo-catalytic degradation of BTB showed that the decomposition rate increased with the TiO2 particle dosages and microwave intensity. When an auxiliary oxidant such as ozone or hydrogen peroxide was added to the microwave-assisted photo-catalysis, however, a synergy effect that enhanced the reaction rate considerably was observed
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