• Title/Summary/Keyword: radiation application

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THE EXTRACTION OF THE THERMAL RADIATION ASSOCIATED WITH GREENHOUSE GASES FROM AIRS MEASUREMENTS

  • Kwon, Eun-Han;Kim, Yong-Seung;Lee, Sun-Gu
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.301-304
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    • 2006
  • For the purpose of investigating the contributions of various gases to climate change, the thermal radiation associated with greenhouse gases are extracted from AIRS (Atmospheric Infrared Sounder) infrared radiances over the tropical pacific region. AIRS instrument which was launched on the EOS-Aqua satellite in May 2002 covers the spectral range from 650 cm-1 to 2700 cm-1 with a spectral resolution of between 0.4 cm-1 and 1 cm-1. In order to extract the thermal radiation absorbed by individual gases, the interfering background radiances at the top of the atmosphere are simulated using the radiative transfer code MODTRAN (MODerate spectral resolution atmospheric TRANsmittance). The simulations incorporated the temperature and water vapor profiles taken from NCEP (National Centers for Environmental Prediction) reanalyses. The differences between the simulated background radiance and AIRS-measured radiance result in the absorption of upward longwave radiation by atmospheric gases (i.e. greenhouse effect). The extracted absorption bands of individual gases will allow us to quantify the radiative forcing of individual greenhouse gases and thus those data will be useful for climate change studies and for the validation of radiative transfer codes used in general circulation models.

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The first KREDOS-EPR intercomparison exercise using alanine pellet dosimeter in South Korea

  • Park, Byeong Ryong;Kim, Jae Seok;Yoo, Jaeryong;Ha, Wi-Ho;Jang, Seongjae;Kang, Yeong-Rok;Kim, HyoJin;Jang, Han-Ki;Han, Ki-Tek;Min, Jeho;Choi, Hoon;Kim, Jeongin;Lee, Jungil;Kim, Hyoungtaek;Kim, Jang-Lyul
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2379-2386
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    • 2020
  • This paper presents the results of the first intercomparison exercise performed by the Korea retrospective dosimetry (KREDOS) working group using electron paramagnetic resonance (EPR) spectroscopy. The intercomparison employed the alanine dosimeter, which is commonly used as the standard dosimeter in EPR methods. Four laboratories participated in the dose assessment of blind samples, and one laboratory carried out irradiation of blind samples. Two types of alanine dosimeters (Bruker and Magnettech) with different geometries were used. Both dosimeters were blindly irradiated at three dose levels (0.60, 2.70, and 8.00 Gy) and four samples per dose were distributed to the participating laboratories. Assessments of blind doses by the laboratories were performed using their own measurement protocols. One laboratory did not participate in the measurements of Magnettech alanine dosimeter samples. Intercomparison results were analyzed by calculating the relative bias, En value, and z-score. The results reported by participating laboratories were overall satisfactory for doses of 2.70 and 8.00 Gy but were considerably overestimated with a relative bias range of 10-95% for 0.60 Gy, which is lower than the minimum detectable dose (MDD) of the alanine dosimeter. After the first intercomparison, participating laboratories are working to improve their alanine-EPR dosimetry systems through continuous meetings and are preparing a second intercomparison exercise for other materials.

Mutant Induction of Several Antifungal Bacteria by Gamma Radiation (60Co) (감마선(60Co) 조사에 의한 항진균 세균의 돌연변이체 유도)

  • Chung, Hye-Young;Kim, Jae-Sung;Cho, Kyu Seong;Lee, Young-Bok;Lee, Young-Keun
    • Korean Journal of Environmental Agriculture
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    • v.21 no.3
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    • pp.216-222
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    • 2002
  • In order to evaluate the antifungal activity of bacteria against plant pathogenic fungi, 8 bacteria were isolated from mushroom compost hot spring, seaweed, and forest soil and mutants from them were induced by $LD_{95}$ gamma radiation($^{60}Co$). Bacillus circulans K1, Burkholderia gladioli K4 and Bacillus subtilis YS1 showed wide antifungal spectrum against 12 kinds of plant pathogenic fungi. From the radiation sensitivity test, B. gladioli K4 was very sensitive to gamma radiation and its $D_{10}$ value was 0.11 kGy. Antifungal activities of B. circulans Kl-1004 and B. subtilis YS1-1009, which were induced by the radiation of $^{60}Co$ increased against Botryosphaeria dothidea. The mutant strains, B. subtilis YS1-1006 and B. subtilis YS1-1009 were resistant to tebuconazole and copper hydroxide. SAR535, SAR5108, and SAR5118 mutated from Streptomyces sp. SAR01 were antifungal activity deficient mutants against 5 kinds of plant pathogenic fungi compared to wild strain, so that they could be supposed to be model strains far studying antifungal mechanism. It is suggested that various functional types of mutants could be induced by gamma radiation and applied usefully.

A Putative Early Response of Antifungal Bacillus lentimorbus WJ5 Against the Plant Pathogenic Fungus, Colletotrichum gloeosporioides, Analyzed by a DNA Microarray

  • Lee Young-Keun;Jang Yu-Sin;Chang Hwa-Hyoung;Hyung Seok Won;Chung Hye-Young
    • Journal of Microbiology
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    • v.43 no.3
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    • pp.308-312
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    • 2005
  • The global RNA transcription profiles of Bacillus lentimorbus WJ5 under an in vitro co-culture with Colletotrichum gloeosporioides were analyzed in order to study the antagonistic bacteria-fungi interactions. Using a filter membrane system, B. lentimorhus WJ5 was exposed to the spores of C. gloeosporioides at the late exponential stage. The transcription profiles of the B. lentimorhus WJ5, both with and without a challenge from C. gloeosporioides, were analyzed using custom DNA chips containing 2,000 genome fragments. A total of 337 genes were expressed, with 87 and 47 up- and down-regulated, respectively. Of these, 12 genes, which were involved in central carbon metabolisms, and 7 from minor catabolism were relatively highly up-regulated (> 10 fold) and down-regulated (< 0.2 fold), respectively. Nine genes, which were thought to be related to the antifungal activity, were also up-regulated, but their levels were not so high (2.0 - 9.7 folds). From the results, during the early stage of the co-culture of B. lentimorbus WJ5 and C. gloeosporioides, nutrient competition seemed to occur; therefore, the genes from central carbon metabolisms could be up-regulated, while those from minor catabolism could be down-regulated.

BIOLOGICAL ACTIVITIES OF PRODUCTS FROM SUGAR CANE BAGASSE FERMENTATION BY Pleurotus sajor-caju (사탕수수 찌꺼기를 이용한 여름느타리 발효부산물의 생물활성)

  • Lee, Young-Keun;Chang, Hwa-Hyoung;Kim, Won-Rok;Kim, Jin-Kyu;Kim, Jae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.17 no.1
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    • pp.39-42
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    • 1998
  • In order to evaluate the biological activities of some fractions from the fungal(Pleurotus sajorcaju) fermentation products of sugar cane bagasses, the antimutagenicity, the glyceollin elicitor activity on soybean and the effect on the stem elongation in pea were observed. The alcohol extract fraction and DMSO soluble fraction had excellent antimutagenicity even though it is weaker than that of the extracts from the fruiting bodies. All of the extracts had the ability to elicit glyceollins in soybean cotyledons and these extracts could be helpful for plants to protect themselves from pathogenic contaminations. IAA and the extracts had shown synergistic effects on pea stem elongation in all experimental groups positively determined.

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