1,249 research outputs found
CANGAROO-III Observation of TeV Gamma Rays from the vicinity of PSR B1 706-44
Observation by the CANGAROO-III stereoscopic system of the Imaging Cherenkov
Telescope has detected extended emission of TeV gamma rays in the vicinity of
the pulsar PSR B170644. The strength of the signal observed as
gamma-ray-like events varies when we apply different ways of emulating
background events. The reason for such uncertainties is argued in relevance to
gamma-rays embedded in the "off-source data", that is, unknown sources and
diffuse emission in the Galactic plane, namely, the existence of a complex
structure of TeV gamma-ray emission around PSR B170644.Comment: 10 pages, 13 figures, to be published in Ap
Performance of the LHD cryogenic system during cooling and excitation tests
Performance of the LHD cryogenic system in the first year\u27s operation was described making importance on the recovery process after the normal transition of the helical coils. During the excitation tests of the LHD superconducting coils up to 2.75 T, the normal zone propagation was observed in the helical coil and the emergency shut-off of the coil power supplies was carried out. 2,700 l of liquid helium evaporated from the helical coils. The coils and the helium refrigerator were separated automatically and the helium refrigerator could keep its steady state operation. After the pressure and flow rate of the recovery gas from the helical coils were settled down to the normal state, the coils were connected to the helium refrigerator and the cooling was restarted. The system could return to the steady state in which coil excitation is enabling, by only three and a half hour
CANGAROO-III observation of TeV gamma rays from the unidentified gamma-ray source HESS J1614-518
We report the detection, with the CANGAROO-III imaging atmospheric Cherenkov
telescope array, of a very high energy gamma-ray signal from the unidentified
gamma-ray source HESS J1614-518, which was discovered in the H.E.S.S. Galactic
plane survey. Diffuse gamma-ray emission was detected above 760 GeV at the 8.9
sigma level during an effective exposure of 54 hr from 2008 May to August. The
spectrum can be represented by a power-law:
8.2+-2.2_{stat}+-2.5_{sys}x10^{-12}x (E/1TeV)^{-Gamma} cm^{-2} s^{-1} TeV^{-1}
with a photon index Gamma of 2.4+-0.3_{stat}+-0.2_{sys}, which is compatible
with that of the H.E.S.S. observations. By combining our result with
multi-wavelength data, we discuss the possible counterparts for HESS J1614-518
and consider radiation mechanisms based on hadronic and leptonic processes for
a supernova remnant, stellar winds from massive stars, and a pulsar wind
nebula. Although a leptonic origin from a pulsar wind nebula driven by an
unknown pulsar remains possible, hadronic-origin emission from an unknown
supernova remnant is preferred.Comment: 9 pages, 7 figures, accepted for publication in Ap
Using shared needles for subcutaneous inoculation can transmit bluetongue virus mechanically between ruminant hosts
Bluetongue virus (BTV) is an economically important arbovirus of ruminants that is transmitted by Culicoides spp. biting midges. BTV infection of ruminants results in a high viraemia, suggesting that repeated sharing of needles between animals could result in its iatrogenic transmission. Studies defining the risk of iatrogenic transmission of blood-borne pathogens by less invasive routes, such as subcutaneous or intradermal inoculations are rare, even though the sharing of needles is common practice for these inoculation routes in the veterinary sector. Here we demonstrate that BTV can be transmitted by needle sharing during subcutaneous inoculation, despite the absence of visible blood contamination of the needles. The incubation period, measured from sharing of needles, to detection of BTV in the recipient sheep or cattle, was substantially longer than has previously been reported after experimental infection of ruminants by either direct inoculation of virus, or through blood feeding by infected Culicoides. Although such mechanical transmission is most likely rare under field condition, these results are likely to influence future advice given in relation to sharing needles during veterinary vaccination campaigns and will also be of interest for the public health sector considering the risk of pathogen transmission during subcutaneous inoculations with re-used needles
Stretchable and wearable colorimetric patches based on thermoresponsive plasmonic microgels embedded in a hydrogel film
Stimuli-responsive colorimetric sensors are promising for various industrial and medical applications due to the capability of simple, fast, and inexpensive visualization of external stimuli. Here we demonstrate a thermoresponsive, smart colorimetric patch based on a thermoresponsive plasmonic microgel embedded in a stretchable hydrogel film. To achieve a fast and efficient thermoresponsive color change, raspberry-shaped plasmonic microgels were fabricated by decorating gold nanoparticles (AuNPs) on poly(N-isopropylacrylamide) (PNIPAM) microgels, which exhibit reversible and strain-insensitive color shifts (between red and grayish violet) in response to a temperature change. The smart colorimetric patch containing a plasmonic microgels exhibits a significant extinction peak shift (176 nm) in a short time (1 s), with a temperature-sensing resolution of 0.2 degrees C. Moreover, the transition temperature of the plasmonic microgel can be finely tuned by additives and comonomers, so that the exquisite temperature visualization can be conducted over a wide temperature range of 25-40 degrees C by assembling plasmonic microgel films with different transition temperatures into an array patch. For proof-of-concept demonstrations, a freestanding smart colorimetric patch was utilized as a spatial temperature scanner and a colorimetric thermometer for a thermoresponsive actuator, which is potentially applicable in smart, wearable sensors and soft robotics
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