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Infrared signal measurements from a micro-turbojet engine are conducted to understand the characteristics of the engine performance and the infrared signal by varying the exhaust nozzle configuration. A cone type nozzle and five rectangle type nozzles whose aspect ratios vary from one to five are used for this experimental work. As a result, it is confirmed that the thrust and the fuel consumption rate of the engine do not change greatly by varying the exhaust nozzle shape. In the case of the aspect ratio of 5, the specific fuel consumption of the engine is increased by about 3% compared to the reference cone nozzle, but the infrared signal can be reduced by up to 14%. As a result of measuring the temperature distribution of the plume gas, the correlation of infrared signal with plume gas temperature distribution can be understood. In the case of a cone shape, the distribution of plume gas formed to circular shape, and the high-temperature core region of plume gas continued to develop farther to the downstream. However, the temperature distribution was maintained in the rectangular shape as the aspect ratio increased, and the average temperature decreased sharply. As the aspect ratio increases, the plume spreads more widely.
Gilliland et al. (2000) have reported HST photometric observations of 34000 stars in the globular cluster 47 Tuc, showing an absence of close-in giant planets in that cluster relative to their frequency in the solar neighborhood. Here we describe the methods of time-series analysis that were used to search the 47 Tuc data for transits by giant extrasolar planets, and the means by which these methods were validated.
Δ14C values of leaves of deciduous trees provide a means to map the regional-scale fossil fuel ratio in the atmosphere. We collected a batch of ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples from across Korea in the month of July in both 2010 and 2011 to obtain the regional distribution of Δ14C. The Δ14C values of the samples were measured using accelerator mass spectrometry (AMS) at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The average of the Δ14C values from clean air sites in Korea in 2011 measured slightly lower than the average of Δ14C values in 2010. Distribution maps of Δ14C of 2011 and 2010 in Korea were made based on a series of Δ14C values of ginkgo leaf samples from Korea using the Geostatistical and Spatial analyst tools in ESRI's ArcMap software. The distribution maps of Δ14C showed that Δ14C values in the western part of Korea are lower than those in the eastern part of Korea. This is because the western part of Korea is densely populated and contains many industrial complexes, and also because westerly winds from China, containing CO2 from fossil fuel use, blow into Korea. We compared the distribution maps of 2010 and 2011 and tried to find traces of the Fukushima power plant accident in Japan.
In February 2012, an outbreak of gastroenteritis was reported in school A; a successive outbreak was reported at school B. A retrospective cohort study conducted in school A showed that seasoned green seaweed with radishes (relative risk 7·9, 95% confidence interval 1·1–56·2) was significantly associated with illness. Similarly, a case-control study of students at school B showed that cases were 5·1 (95% confidence interval 1·1–24·8) times more likely to have eaten seasoned green seaweed with pears. Multiple norovirus genotypes were detected in samples from students in schools A and B. Norovirus GII.6 isolated from schools A and B were phylogenetically indistinguishable. Green seaweed was supplied by company X, and norovirus GII.4 was isolated from samples of green seaweed. Green seaweed was assumed to be linked to these outbreaks. To our knowledge, this is the first reported norovirus outbreak associated with green seaweed.
Individuals with borderline personality disorder (BPD) frequently display co-morbid mental disorders. These disorders include ‘internalizing’ disorders (such as major depressive disorder and anxiety disorders) and ‘externalizing’ disorders (such as substance use disorders and antisocial personality disorder). It is hypothesized that these disorders may arise from latent ‘internalizing’ and ‘externalizing’ liability factors. Factor analytic studies suggest that internalizing and externalizing factors both contribute to BPD, but the extent to which such contributions are familial is unknown.
Participants were 368 probands (132 with BPD; 134 without BPD; and 102 with major depressive disorder) and 885 siblings and parents of probands. Participants were administered the Diagnostic Interview for DSM-IV Personality Disorders, the Revised Diagnostic Interview for Borderlines, and the Structured Clinical Interview for DSM-IV.
On confirmatory factor analysis of within-person associations of disorders, BPD loaded moderately on internalizing (factor loading 0.53, s.e. = 0.10, p < 0.001) and externalizing latent variables (0.48, s.e. = 0.10, p < 0.001). Within-family associations were assessed using structural equation models of familial and non-familial factors for BPD, internalizing disorders, and externalizing disorders. In a Cholesky decomposition model, 84% (s.e. = 17%, p < 0.001) of the association of BPD with internalizing and externalizing factors was accounted for by familial contributions.
Familial internalizing and externalizing liability factors are both associated with, and therefore may mutually contribute to, BPD. These familial contributions account largely for the pattern of co-morbidity between BPD and internalizing and externalizing disorders.
The Ultra-Fast Flash Observatory (UFFO) is a space observatory for optical follow-ups of
gamma ray bursts (GRBs), aiming to explore the first 60 seconds of GRBs optical emission.
UFFO is utilized to catch early optical emissions from GRBs within few sec after trigger
using a Gimbal mirror which redirects the optical path rather than slewing entire
spacecraft. We have developed a 15 cm two-axis Gimbal mirror stage for the UFFO-Pathfinder
which is going to be on board the Lomonosov satellite which is to be launched in 2013. The
stage is designed for fast and accurate motion with given budgets of 3 kg of mass and 3
Watt of power. By employing stepping motors, the slewing mirror can rotate faster than 15
deg/sec so that objects in the UFFO coverage (60 deg × 60 deg) can be targeted in
~1 sec. The obtained targeting resolution is better 2 arcmin using a close-loop
control with high precision rotary encoder. In this presentation, we will discuss details
of design, manufacturing, space qualification tests, as well as performance tests.
The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. The
SMT optical system is a Ritchey-Chrétien (RC) telescope of 100 mm diameter pointed by
means of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a
17 × 17arcmin2 in Field of View and 4.3 arcsec resolution (full width half
maximum of the point spread function) The beam-steering mirror enables the SMT to access a
35 × 35degree region and point and settle within 1 sec. All mirrors were fabricated to
about 0.02 wavelengths RMS in wave front error (WFE) and 84.7% average reflectivity over
200 nm ~ 650 nm. The RC telescope was aligned to 0.05 wavelengths RMS in WFE (test
wavelength 632.8 nm). In this paper, the technical details of the RC telescope and slewing
mirror system assembly, integration, and testing are given shortly, and performance tests
of the full SMT optical system are reported.
The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov
satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector,
called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB
and then triggers to determine the direction of the GRB and then alerts the Slewing Mirror
Telescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes.
This report details the calibration of the two components: the MAPMTs and the YSO crystals
and simulations of the UBAT. The results shows that this design can observe a GRB within a
field of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 s
after the appearance of a GRB X-ray spike.
One of the key aspects of the upcoming Ultra-Fast Flash Observatory (UFFO) pathfinder for
Gamma Ray Bursts (GRBs) identification is the UFFO Burst Alert & Trigger Telescope
(UBAT). The scientific propose of UBAT is to detect and locate as fast as possible the
GRBs in the sky. This is achieved by using a coded mask aperture camera scheme with a wide
field of view (FOV) and selecting a X-ray detector of high quantum efficiency and large
detection area. This X-ray detector of high quantum efficiency and large detection area is
called the UBAT detector. The UBAT detector consists of 48 × 48 Yttrium Oxyorthosilicate
(YSO) scintillator crystal arrays and Multi Anode Photomultiplier Tubes (MAPMTs), analog
electronics equipped with ASIC chips, digital electronics equipped with Field Programmable
Gate Array (FPGA) chips, and a mechanical structure that supports all components of the
UBAT detector. The total number of the pixels in the UBAT detector is 2304, and the total
effective detection area is 191 cm2. We will present the design and
construction, and performance of the UBAT detector including the responses of the UBAT
detector to X-ray sources.
The Ultra-Fast Flash Observatory (UFFO) aims to detect the earliest moment of Gamma-Ray
Bursts (GRBs) which is not well known, resulting into the enhancement of GRB mechanism
understanding. The pathfinder mission was proposed to be a scaled-down version of UFFO,
and only contains the UFFO Burst Alert & Trigger Telescope (UBAT) measuring the
X-ray/gamma-ray with the wide-field of view and the Slewing Mirror Telescope (SMT) with a
rapid-response for the UV/optical photons. Once the UBAT detects a GRB candidate with the
position accuracy of 10 arcmin, the SMT steers the UV/optical photons from the candidate
to the telescope by the fast rotatable mirror and provides the early UV/optical photons
measurements with 4 arcsec accuracy. The SMT has a modified Ritchey-Chrètien telescope
with the aperture size of 10 cm diameter including the rotatable mirror and the image
readout by the intensified charge-coupled device. There is a key board called the UFFO
Data Acquisition system (UDAQ) that manages the communication of each telescope and also
of the satellite and the UFFO overall operation. This pathfinder is designed and built
within the limited size and weight of ~20 kg and the low power consumption up to
~30 W. We will discuss the design and performance of the UFFO-pathfinder, and its
integration to the Lomonosov satellite.
The Ultra-Fast Flash Observatory (UFFO), which will be launched onboard the
Lomonosov spacecraft, contains two crucial instruments: UFFO Burst
Alert & Trigger Telescope (UBAT) for detection and localization of Gamma-Ray Bursts
(GRBs) and the fast-response Slewing Mirror Telescope (SMT) designed for the observation
of the prompt optical/UV counterparts. Here we discuss the in-space calibrations of the
UBAT detector and SMT telescope. After the launch, the observations of the standard X-ray
sources such as pulsar in Crab nebula will provide data for necessary calibrations of
UBAT. Several standard stars will be used for the photometric calibration of SMT. The
celestial X-ray sources, e.g. X-ray binaries with bright optical sources
in their close angular vicinity will serve for the cross-calibration of UBAT and SMT.
The Ultra-Fast Flash Observatory (UFFO) Pathfinder for Gamma-Ray Bursts (GRBs) consists
of two telescopes. The UFFO Burst Alert & Trigger Telescope (UBAT) handles the
detection and localization of GRBs, and the Slewing Mirror Telescope (SMT) conducts the
measurement of the UV/optical afterglow. UBAT is equipped with an X-ray detector, analog
and digital signal readout electronics that detects X-rays from GRBs and determines the
location. SMT is equipped with a stepping motor and the associated electronics to rotate
the slewing mirror targeting the GRBs identified by UBAT. First the slewing mirror points
to a GRB, then SMT obtains the optical image of the GRB using the intensified CCD and its
readout electronics. The UFFO Data Acquisition system (UDAQ) is responsible for the
overall function and operation of the observatory and the communication with the satellite
main processor. In this paper we present the design and implementation of the electronics
of UBAT and SMT as well as the architecture and implementation of UDAQ.
One of the unexplored domains in the study of gamma-ray bursts (GRBs) is the early time
phase of the optical light curve. We have proposed Ultra-Fast Flash Observatory (UFFO) to
address this question through extraordinary opportunities presented by a series of small
space missions. The UFFO is equipped with a fast-response Slewing Mirror Telescope that
uses a rapidly moving mirror or mirror array to redirect the optical beam rather than
slewing the entire spacecraft or telescope to aim the optical instrument at the GRB
position. The UFFO will probe the early optical rise of GRBs with sub-second response, for
the first time, opening a completely new frontier in GRB and transient studies. Its fast
response measurements of the optical emission of dozens of GRB each year will provide
unique probes of the burst mechanism and test the prospect of GRB as a new standard
candle, potentially opening up the z > 10 universe. We describe the current limit in
early photon measurements, the aspects of early photon physics, our soon-to-be-launched
UFFO-pathfinder mission, and our next planned mission, the UFFO-100.
The dynamics of influenza A viral load in respiratory samples collected from adult A(H1N1)pdm09 influenza patients were investigated. Three respiratory specimens were obtained every 2–4 days and clinical findings were recorded at the time each specimen was collected. A total of 105 serial specimens were collected from 35 patients. Viral clearance was more rapid in patients aged 15–29 years than patients aged 30–49 years (P < 0·01) or ⩾50 years (P < 0·01). Hospitalized patients showed slow viral clearance compared to outpatients (P < 0·01). Resolution of cough and headache was correlated with viral load reduction in respiratory specimens. Viral shedding was found in 17 patients (48·6%) 5 days after symptom onset. Time to hospital visit after symptom onset was significantly correlated with prolonged viral shedding (odds ratio 9·0, 95% confidence interval 1·56–51·87, P = 0·01). These findings will contribute to infection control aspects with respect to managing patients with influenza virus infections.