• Title/Summary/Keyword: Rays

Search Result 2,317, Processing Time 0.025 seconds

First Record of the Gobiid fish, Clariger chionomaculatus (Perciformes: Gobiidae) from off Geojedo Island, Korea (우리나라 거제도 연안에서 채집된 망둑어과 첫기록종, Clariger chionomaculatus)

  • Cho, Hyun-Geun;Kim, Byung-Jik
    • Korean Journal of Ichthyology
    • /
    • v.32 no.2
    • /
    • pp.110-114
    • /
    • 2020
  • A single specimen (40.5 mm in SL) of Clariger chionomaculatus was collected at 4 m depth on mud bottom from off Geojedo Island, Korea. This species is characterized by having an elongated body without scales, several barbels below eyes, I, 12~15 second dorsal fin rays, I, 12~14 anal fin rays; 19~20 pectoral fin rays with one free soft ray on upper part, and a unique color pattern with numerous white blotches on dorsal part of body. Because it has been known from Japan only to date, we describe in detail C. chionomaculatus as the first record from Korea. A new Korean name, "Huin-jeom-wae-mang-dug", is proposed for the species.

THE CONTRIBUTION TO THE EXTRAGALACTIC γ-RAY BACKGROUND BY HADRONIC INTERACTIONS OF COSMIC RAYS PRODUCING EUV EMISSION IN CLUSTERS OF GALAXIES

  • KUO PING-HUNG;BOWYER STUART;HWANG CHORNG- YUAN
    • Journal of The Korean Astronomical Society
    • /
    • v.37 no.5
    • /
    • pp.597-600
    • /
    • 2004
  • A substantial number of processes have been suggested as possible contributors to the extragalactic $\gamma$-ray background (EGRB). Yet another contribution to this background will be emission produced in hadronic interactions of cosmic-ray protons with the cluster thermal gas; this class of cosmic rays (CRs) has been shown to be responsible for the EUV emission in the Coma Cluster of galaxies. In this paper we assume the CRs in the Coma Cluster is prototypic of all clusters and derive the contribution to the EGRB from all clusters over time. We examine two different possibilities for the scaling of the CR flux with cluster size: the number density of the CRs scale with the number density of the thermal plasma, and alternatively, the energy density of the CRs scale with the energy density of the plasma. We find that in all scenarios the EGRB produced by this process is sufficiently low that it will not be observable in comparison with other mechanisms that are likely to produce an EGRB.

GPS QUASARS AS SPECIAL BLAZARS

  • BAI J. M.;LEE MYUNG GYONG
    • Journal of The Korean Astronomical Society
    • /
    • v.38 no.2
    • /
    • pp.125-128
    • /
    • 2005
  • In this paper, we argue that the gigahertz peaked spectrum (GPS) quasars are special blazars, blazars in dense and dusty gas enviornment. The ROSAT detection rate of GPS quasars is similar to that of flat spectrum radio quasars (FSRQs), suggesting that the relativistic jets in GPS quasars are oriented at small angle to the line of sight. Due to strong inverse Compton scattering off infrared photons from dense and dusty nuclear interstellar media in GPS quasars, most of them may have significant soft gamma-ray and X-ray emission, which is consistent with ASCA X-ray observations. Because Compton cooling in GPS quasars is stronger than that in FSRQs, synchrotron emission in GPS quasars may less dominate over thermal emission of the accretion disk and hot dust, hence most GPS quasars show low optical polarization and small variability, consistent with observations. We suggest that it is the significant radio emission of electron/positron pairs produced by the interaction of gamma-rays with the dense gas and dust grains in GPS quasars that makes GPS quasars show steep radio spectra, low radio polarization, and relatively faint VLBI/VLBA cores. Whether GPS quasars are special blazars can be tested by gamma-ray observations with GLAST in the near future, with the detection rate of GPS quasars being similar to that of FSRQs.

Innovative Electromagnetic Induction Eddy Current-based Far Infrared Rays Radiant Heater using Soft Switching PWM Inverter with Duty Cycle Control Scheme

  • Tanaka H.;Sadakata H.;Muraoka H.;Okuno A.;Hiraki E.;Nakaoka M.
    • Proceedings of the KIPE Conference
    • /
    • 2001.10a
    • /
    • pp.64-68
    • /
    • 2001
  • This paper presents an innovative prototype of a new conceptual electromagnetic induction heated type far infrared rays radiant heating appliance using the voltage-fed edge-resonant ZVS-PWM high frequency inverter using IGBTs for food cooking and processing which operates under a constant frequency variable power regulation scheme. This power electronic appliance with soft switching high frequency inverter using IGBTs has attracted special interest from some advantageous viewpoints of safety, cleanliness, compactness and rapid temperature response, which is more suitable for consumer power electronics applications.

  • PDF

Estimation of Neutron Energy Spectrum of Cf-252 using Single Bonner Sphere with TLD-600 and TLD-700 (단일 보너구와 TLD-600 및 TLD-700을 이용한 Cf-252의 중성자 에너지 스펙트럼 평가)

  • Kim, Sunghwan;Cheon, Jongkyu;Lee, Jae Jin;Nam, Uk-Won
    • Journal of Sensor Science and Technology
    • /
    • v.22 no.3
    • /
    • pp.223-226
    • /
    • 2013
  • We designed a single polyethylene bonner sphere with several thermo-luminescence dosimeters (TLD), for measurement of neutron energy spectrum. For the separation of the neutron dosage in the neutron-gamma mixed field, we used 21 ea TLD-600s and TLD-700s, respectively. Because, TLD-600 is sensitive to neutron and gamma rays, and, TLD-700 is sensitive only to gamma-rays, we could determine the each dose by neutron and gamma rays. The neutron response function of the bonner sphere with TLDs was calculated by MCNPX (ver. 2.5.0) Monte Carlo simulation in the energy range from $10^{-1}$ to 20 MeV. For the Cf-252 standard neutron source in KRISS, we could estimate the neutron energy spectrum by unfolding method using the response function.

Climate Influences of Galactic Cosmic Rays (GCR): Review and Implications for Research Policy (우주기원의 고에너지 입자가 기후에 미치는 영향: 연구 현황과 정책적 시사점)

  • Kim, Jiyoung;Jang, Kun-Il
    • Atmosphere
    • /
    • v.27 no.4
    • /
    • pp.499-509
    • /
    • 2017
  • Possible links among cosmic ray, cloud, and climate have scientific uncertainties. The reputed topics have been highly controversial during several decades. A link between the atmospheric ionization by galactic cosmic rays (GCR), which is modulated by solar activities, and global cloud cover was firstly proposed in 1997. Some researchers suggested that the GCR can stimulate the formation of cloud condensation nuclei (CCN) in the atmosphere, and then the higher CCN concentrations may lead to an increase of cloud cover, resulting in a cooling of the Earth's climate, and vise versa. The CLOUD (Cosmic leaving outdoor droplets) experiment was designed to study the effect of GCR on the formation of atmospheric aerosols and clouds under precisely controlled laboratory conditions. A state-of-the-art chamber experiment has greatly advanced our scientific understanding of the aerosol formation in early stage and its nucleation processes if the GCR effect is considered or not. Many studies on the climate-GCR (or space weather) connection including the CLOUD experiment have been carried out during the several decades. Although it may not be easy to clarify the physical connection, the recent scientific approaches such as the laboratory experiments or modeling studies give some implications that the research definitively contributed to reduce the scientific uncertainties of natural and anthropogenic aerosol radiative forcing as well as to better understand the formation processes of fine particulate matters as an important parameter of air quality forecast.

A Study of Characteristic of Oriental Herbal Medicine Storage System using Ozone Lamp (오존램프를 이용한 한약재 저장 장치의 특성 연구)

  • Woo, Sung-Hun;Lee, Kwang-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.1
    • /
    • pp.98-103
    • /
    • 2007
  • We made a oriental herbal medicine storage system and studied a preservation characteristic of oriental herbal medicine in this research. The lamp(OZ-Lamp) in a storage system is the low pressure ultraviolet lamp which radiates the sterilizing and ozonic rays. We made research ozone generation and electric discharge characteristic of a oriental herbal medicine storage system, which have radiation feature of ultraviolet rays of a short wavelength to be happened in the electric discharge. Also, we made research an ingredient and quality characteristic of oriental herbal medicine according to ozone treatment storage.

Real-time Spray Painting using Rays and Texture Map (레이와 텍스처 기법을 이용한 실시간 스프레이 페인팅)

  • Kim, Dae-Seok;Park, Jin-Ah
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.14 no.8
    • /
    • pp.818-822
    • /
    • 2008
  • The purpose of this study is to develop realistic painting simulation in real-time as well as to represent the thickness of the deposited paint on the surface. The Gaussian model is used for a painting deposition model to calculate the thickness of paints. For a painting simulation, rather than implementing particle systems, we propose a new heuristic algorithm for painting process based on a few number of rays. After we find the collision points of the rays with an environment, we compute the painted area using flood-fill searching method on the texture map and visualize paint effects. We analyzed time complexity of our method to verify that our system is suitable for real-time VR applications.

New Record of a Rare Hypogean Gobiid, Luciogobius pallidus from Jeju Island, Korea (제주도에서 처음 발견된 지하수계 서식 희귀 망둑어류 한국미기록종, Luciogoius pallidus)

  • Kim, Byung-Jik
    • Korean Journal of Ichthyology
    • /
    • v.24 no.4
    • /
    • pp.306-310
    • /
    • 2012
  • A hypogean gobiid, Luciogobius pallidus was described as the first record from Korea and also as the westernmost record of the species from the world, based on four specimens (31.2~53.6 mm SL) collected from Jeju Island, Korea. The species is characterized by having yellowish orange body color with I, 10~11 second dorsal fin rays, I, 10~12 anal fin rays, 13~15 pectoral fin rays, and 36 vertebrae as well as small embedded eyes beneath the skin. A new Korean name, "Juhong-mi-ggeun-mang-dug" was proposed for the species.

Operative Treatment of the Bilateral Multiple Rays Brachymetatarsia using Callotasis (A Case Report) (가골 신연술을 이용한 양측성 다발열 단중족증의 치료 (1예 보고))

  • Kwon, Sai-Won;Park, Kang-Hee;Soh, Jae-Wan
    • Journal of Korean Foot and Ankle Society
    • /
    • v.14 no.2
    • /
    • pp.186-189
    • /
    • 2010
  • Among congenital brachymetatarsias fourth metatarsal bone shortening is most common form and unusually involves multiple metatarsal bones. We report a case of the patient with bilateral 1st and 4th multiple rays brachymetatarsia treated with callostasis. Twenty eight months after procedure, right side showed 1st metatarsal lengthening about 11.5 mm (29.23%) and 4th metatarsal 17.86 mm (35.87%). Twenty one months later, left side showed 1st metatarsal lengthening about 14.58 mm (36.8%) and 4th metatarsal 20.52 mm (43.01%). In healing index right side showed 1st metatarsal 3.4 month/cm, 4th metatarsal 2.5 month/cm and left side showed 1st metatarsal 4.2 month/cm, 4th metatarsal 2.3 month/cm. Final follow-up results presented excellent outcome in cosmetic problem, easy wear of shoes, and measurement of patient's self satisfaction.