• Title/Summary/Keyword: Rays

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Growth-inhibitory Effect of the Sun-dried Salts and Gamma rays on Microorganisms Isolated from Korean Traditional Raw Rice Wine (천일염과 감마선이 막걸리의 미생물 생장 억제에 미치는 효과)

  • Nam, Ji-Young;Kim, Jae-Hun;Lee, Ju-Woon;Kim, Jin-Kyu
    • Korean Journal of Environmental Biology
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    • v.28 no.4
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    • pp.218-222
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    • 2010
  • This study was carried out to investigate the changes in the storage characteristics of the Korean traditional raw rice wine (RRW) treated with Korean sun-dried salts and gamma rays. Nowadays, RRWs have received attention because they are a nutritious food with health-stimulating properties. But the rapid deterioration of the fermented RRW is one of the serious problems for brewing and marketing in the world. Actually, the expiry date of the RRW is around a week and this has been a biggest disadvantage of the RRW. The goal of this study was to make it of high quality and extend the period of circulation of the RRW. A lactic acid bacterium was isolated from the RRW. The 16S rRNA sequences of isolates showed 98% homology with the Lactobacillus fermentum. These results suggested that could be manageable improve the shelf life with addition of the sun-dried salts and irradiation with gamma rays.

Description of a Postflexion Larva Specimen of Liopropoma japonicum (Döderlein) off Jeju Island, Korea (제주도 근해에서 채집된 가시우럭(Liopropoma japonicum) 후기자어의 외부형태 관찰)

  • Kim, Sung;Yoo, Jae-Myung;Lee, Eun-Kyung
    • Ocean and Polar Research
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    • v.26 no.4
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    • pp.685-688
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    • 2004
  • The morphology of the post-larva of Liopropoma japonicum of the family serranidae is described from one specimen collected off Jeju Island ($32^{\circ}42'N,\;127^{\circ}45'E$) on May 3, 2001. The body is laterally compressed and caudal peduncle deep at 19.4 mm BL. Anus locates at a vertical through posteriormost(8th) dorsal-fin spine. Dorsal fin rays were VIII, 14; anal fin rays III, 10; pectroal fin rays 16; pelvic fin rays I, 5. A caudal fin is rounded. Length of elongate second and third dorsal-fin spines are 499% and 423% of the body length, respectively. A series of 50 sensory pores on body is elongated to caudal fin. Head spination is well developed. Melanophores are moderately large and dense in the head, and are small and rare in teh neck. Being freshly collected, the body color is yellowish-red and tail is semitransparent. The head is yellowish-red and the brain is dark-red.

Re-identification of Two Tonguefishes (Pleuronectiformes) from Korea using Morphological and Molecular Analyses (형태 및 분자분석에 의한 한국산 참서대과 어류(가자미목) 2종의 재동정)

  • Kwun, Hyuck Joon;Kim, Jin-Koo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.2
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    • pp.208-213
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    • 2016
  • The re-identification of two Korean tonguefishes, Cynoglossus interruptus and Symphurus orientalis, was carried out using eight specimens collected from Korean waters in 2007 and 2013. C. interruptus is characterized by having a single row of scales between rows connected to the supraorbital line and the middle lateral line, 107–113 dorsal fin rays, 86–89 anal fin rays, and 53–55 vertebrae. S. orientalis is characterized by having a 1-2-2-2-2 ID pattern, 97–100 dorsal fin rays, 83–89 anal fin rays, and 52–55 vertebrae. Molecular analysis using mitochondrial DNA Cytochrome Oxidase subunit I sequences showed that specimens of the two species corresponded well to Japanese C. interruptus and Taiwanese S. orientalis, respectively. Therefore, although several reports have raised questions regarding the distribution of C. interruptus and S. orientalis in Korean waters, morphological and molecular data confirm that these two species are indeed distributed in these waters.

Wood Anatomy of Some Korean Angiosperm (II) - A Comparative Wood Anatomy of Juglandaceae - (국산(國産) 활엽수재(闊葉樹材) 자원(資源)의 목재조직(木材組織) (II) - 가래나무과(科) 수목(樹木)의 비교목부조직(比較木部組織) -)

  • Park, Sang-Jin;Kang, Ae-Kyung;Kim, You-Jung;Kim, Jae-Woo;Lee, Jung-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.82-87
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    • 1995
  • Anatomical characteristics of genus Platycarya, Juglans and Pterocarya of Juglandaceae occurring in Korea were described and coded based on the IAWA list. Juglandaceae are ring-porous or semi-ring-porous. Vessels have simple perforation plates and helical thickenings in some genus. Axial parenchyma cells were abundant, most apotracheal but rarely paratracheal and rays with 1-5 seriate. Platycarya is ring-porous wood with 2-3 rows of vessels in the pore zone. Helical thickenings were found only in small vessel of latewood. Axial parenchyma were commonly diffuse-in-aggregates or vasicentric. Rays 3-5 seriate. belonging to Kribs' heterogeneous II or III type with frequent occurrence of rhomboidal crystals. Juglans are semi ring-porous with few vessels in $mm^2$ and pores are commonly solitary. Axial parenchyma were diffuse-in-aggregate or marginal. Rays were mostly homocellular and 3-5 seriates. Pterocarya is similar to Juglans in anatomical features but the reticulate parenchyma consisting of 1 layer on transverse section and biseriate rays.

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The Genetic Studies of Drosophila Population 2. On the frequencies of reciprocal translocation in D. melanogaster irradiated with X-rays (초파리집단의 유전학적 연구 2. X-선조사에 의한 상호 전좌 유발 빈도에 관하여)

  • 강영선;이정수
    • The Korean Journal of Zoology
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    • v.8 no.2
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    • pp.9-14
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    • 1965
  • The frequency of reicprocal translocation damage in males of D. melanogaster irradiated with X-rays was observed in this study. The frequencies were checked at four periods with two days intervals and duration spermatogenesis after irradiation. (1) Modification in the percentage of the reciprocal translocation damage were not obtained at interval after irradiated with 500r and 1500r of X-rays respectively. (2) In two experimental groups irradiated with 50-0r and 1500r of X-rays, the frequencies showing in the spermatogenesis were 0.50%(500r), 3.85%(1500r) in mature sperm, and 1.59%, 8.10% in the spermatocyte. (3) The frequency of reciprocal translocation between the Y and 3 rd chromosomes was the highest, but in accordance with dosage increase that of 2nd and 3rd chromosomes relatively increased from 9.34 % to 30.49% while decreased from 68.75% to 46.80% in the group of the Y and 3 rd chromosomes. (4) It was supposed that these modifications of the frequency were due to heavy damage of the 2nd chromosomes than other chromosomes in accordance with dosage increase. (5) Spontaneous reciprocal translocations involving the Y, 2nd and 3rd chormosomes was 0.23%.

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Defect Analysis of Phospher (Ba, Sr) FBr : Eu by X-Ray Irradiation (X선 조사에 의해 (Ba, Sr) FBr : Eu 형광 물질에 생성되는 결함 특성)

  • Shin, Jung-Ki;Lee, Chong-Yong;Bae, Seok-Hwan;Kim, Jae-Hong;Kwon, Jun-Hyun
    • Korean Journal of Materials Research
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    • v.18 no.8
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    • pp.427-431
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    • 2008
  • The mechanical property of a phosphore layer was investigated by measuring the resolution (LP/mm) and by positron annihilation spectroscopy and SEM. Image plate samples containing the phosphore layer were irradiated by X-rays in a hospital numerous times over a course of several years. The LP/mm values of a (Ba,Sr)FBr : Eu image plate irradiated by X-rays varied between 2.2 and 2.0 over a period of four years. Coincidence Doppler Broadening (CDB) positron annihilation spectroscopy was used to analyze defect structures. The S parameters of the samples from hospital use varied from 0.6219 to 0.6232. There was a positive relationship between the time of exposure to the X-rays and the S parameters. Most of the defects were found to have been generated by X-rays.

Electromagnetic Wave Propagation Characteristics from Large Scale Random Rough Surfaces (큰 규모의 불규칙 조면에 의한 전자파 전파 특성)

  • Yoon Kwang-Yeol;Chai Yong-Yoong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.4 s.107
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    • pp.393-399
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    • 2006
  • In this paper we applied a ray tracing method to estimate the scattering characteristics from large scale random rough surfaces. For the electromagnetic field evaluation, we have used the diffracted coefficient of the knife edge diffraction for the diffracted rays and Fresnel's reflection coefficients in connection with reflected rays. In addition, we examine to search for the traced rays using the imaging method which can be obtained all rays to arrived at receivers accurately and the diffracted field from rough surfaces is considered. Numerical examples have been carried out for the scattering characteristics of an ocean wave-like rough surface and delay spread characteristics of a building-like surface. In the present work we have demonstrated that the ray tracing method is effective to numerical analysis of a rough surface scattering.

First Record of the Frogfishes Antennarius pictus (Antennariidae, Lophiiformes) from Korea (한국산 씬벵이과 어류 1미기록종 Antennarius pictus)

  • Kim, Byung-Yeob;Kim, Maeng-Jin;Song, Choon-Bok
    • Korean Journal of Ichthyology
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    • v.23 no.2
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    • pp.168-171
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    • 2011
  • Two specimens of Antennarius pictus, belonging to the family Antennariidae, were collected from the coastal waters of Jeju Island, Korea. They were characterized by having 7 anal fin rays, 10 pectoral fin rays, 12 dorsal fin rays, 9 caudal fin rays, and second spine of dorsal fin diminishing and curved backwards distally. Since this species has various sizes of round black spots on head, body and fins, we propose a new Korean fish name "Heuk-jum-bak-ssin-beng-i" for A. pictus.

CLUSTERS OF GALAXIES: SHOCK WAVES AND COSMIC RAYS

  • RYU DONGSU;KANG HYESUNG
    • Journal of The Korean Astronomical Society
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    • v.36 no.3
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    • pp.105-110
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    • 2003
  • Recent observations of galaxy clusters in radio and X-ray indicate that cosmic rays and magnetic fields may be energetically important in the intracluster medium. According to the estimates based on theses observational studies, the combined pressure of these two components of the intracluster medium may range between $10\%{\~}100\%$ of gas pressure, although their total energy is probably time dependent. Hence, these non-thermal components may have influenced the formation and evolution of cosmic structures, and may provide unique and vital diagnostic information through various radiations emitted via their interactions with surrounding matter and cosmic background photons. We suggest that shock waves associated with cosmic structures, along with individual sources such as active galactic nuclei and radio galaxies, supply the cosmic rays and magnetic fields to the intracluster medium and to surrounding large scale structures. In order to study 1) the properties of cosmic shock waves emerging during the large scale structure formation of the universe, and 2) the dynamical influence of cosmic rays, which were ejected by AGN-like sources into the intracluster medium, on structure formation, we have performed two sets of N-body /hydrodynamic simulations of cosmic structure formation. In this contribution, we report the preliminary results of these simulations.

Estimation of nuclear heating by delayed gamma rays from radioactive structural materials of HANARO

  • Noh, Tae-yang;Park, Byung-Gun;Kim, Myong-Seop
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.446-452
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    • 2018
  • To improve the accuracy and safety of irradiation tests in High flux Advanced Neutron Application ReactOr (HANARO), the nuclear energy deposition rate, which is called nuclear heating, was estimated for an irradiation capsule with an iridium sample in the irradiation hole in order. The gamma rays emitted from the radioisotopes (RIs) of the structural materials such as flow tubes of fuel assemblies and heavy water reflector tank were considered as radiation source. Using the ORIGEN2.1 code, emission rates of delayed gamma rays were calculated in consideration of the activation procedure for 8 years and 2 months of HANARO operation. Calculated emission rates were used as a source term of delayed gamma rays in the MCNP6 code. By using the MCNP code, the nuclear heating rates of the irradiation capsules in the inner core, outer core, and heavy water reflector tank were estimated. Calculated nuclear heating in the inner core, outer core, and heavy water reflector tank were 200-260 mW, 80-100 mW, and 10 mW, respectively.