Camera for QUasars in EArly uNiverse (CQUEAN)

We describe the overall characteristics and the performance of an optical CCD camera system, Camera for QUasars in EArly uNiverse (CQUEAN), which is being used at the 2.1 m Otto Struve Telescope of the McDonald Observatory since 2010 August. CQUEAN was developed for follow-up imaging observations of red sources such as high redshift quasar candidates (z >= 5), Gamma Ray Bursts, brown dwarfs, and young stellar objects. For efficient observations of the red objects, CQUEAN has a science camera with a deep depletion CCD chip which boasts a higher quantum efficiency at 0.7 - 1.1 um than conventional CCD chips. The camera was developed in a short time scale (~ one year), and has been working reliably. By employing an auto-guiding system and a focal reducer to enhance the field of view on the classical Cassegrain focus, we achieve a stable guiding in 20 minute exposures, an imaging quality with FWHM >= 0.6" over the whole field (4.8' * 4.8'), and a limiting magnitude of z = 23.4 AB mag at 5-sigma with one hour total integration time.Comment: Accepted for publication in PASP. 26 pages including 5 tables and 24 figure

A study on fire design accidental loads for aluminum safety helidecks

AbstractThe helideck structure must satisfy the safety requirements associated with various environmental and accidental loads. Especially, there have been a number of fire accidents offshore due to helicopter collision (take-off and/or landing) in recent decades. To prevent further accidents, a substantial amount of effort has been directed toward the management of fire in the safety design of offshore helidecks. The aims of this study are to introduce and apply a procedure for quantitative risk assessment and management of fires by defining the fire loads with an applied example. The frequency of helicopter accidents are considered, and design accidental levels are applied. The proposed procedures for determining design fire loads can be efficiently applied in offshore helideck development projects

Colorectal Lymphoid Polyposis in a Child

Lymphoid polyposis is a lymphoid hyperplasia of the gastrointestinal tract that usually presents as multiple small polyps in the colon during childhood. This should be differentiated from other neoplastic or familial polyposis of the intestine. We report a case of benign lymphoid polyposis of the colon in a 17-month-old boy who presented with perianal fistula and mucosal ulceration. Colon study and rectal examinations showed multiple polyps in the sigmoid colon and rectum. Segmental resection of the sigmoid colon and rectum showed over 100 smallt 3 - 7 mrn) sessile or pedunculated polyps that were diffusely scattered through out the removed segment. The polyps consisted of mature lymphoid tissue with numerous germinal centers, that was located mostly in the lamina propria and submucosa

Juvenile Angiodysplasia of Gut

Angiodysplasia or arteriovenous malformation of the gastrointestinal tract in younger patients is different from "classic" angiodysplasia in older patients, by age of onset, clinical presentation, location of the lesion and diverse histologic features, We report two cases of juvenile angiodysplasia of the gut. The diagnosis was suspected by radionuclide blood pool scan and was confirmed by resection and pathological examination, Both cases were girls of 5 years and 12 years of age, and the lesions were in the jejunum and ileum, Grossly, one case showed multiple petechiae and another case showed a hemorrhagic polypoid mass, Microscopically, the lesions were composed of irregularly dilated vascular channels in mucosa and submucosa with abnormal proliferation of arteries and veins in submucosa, Both cases are free of recurrence after local resection

Conceptual Design of a Solid State Telescope for Small scale magNetospheric Ionospheric Plasma Experiments

The present paper describes the design of a Solid State Telescope (SST) on board the Korea Astronomy and Space Science Institute satellite-1 (KASISat-1) consisting of four [TBD] nanosatellites. The SST will measure these radiation belt electrons from a low-Earth polar orbit satellite to study mechanisms related to the spatial resolution of electron precipitation, such as electron microbursts, and those related to the measurement of energy dispersion with a high temporal resolution in the sub-auroral regions. We performed a simulation to determine the sensor design of the SST using GEometry ANd Tracking 4 (GEANT4) simulations and the Bethe formula. The simulation was performed in the range of 100 ~ 400 keV considering that the electron, which is to be detected in the space environment. The SST is based on a silicon barrier detector and consists of two telescopes mounted on a satellite to observe the electrons moving along the geomagnetic field (pitch angle 0°) and the quasi-trapped electrons (pitch angle 90°) during observations. We determined the telescope design of the SST in view of previous measurements and the geometrical factor in the cylindrical geometry of Sullivan (1971). With a high spectral resolution of 16 channels over the 100 keV ~ 400 keV energy range, together with the pitch angle information, the designed SST will answer questions regarding the occurrence of microbursts and the interaction with energetic particles. The KASISat-1 is expected to be launched in the latter half of 2020