• Title/Summary/Keyword: LeeJongHyeong

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Detection of Thermal Ratcheting Deformation for Cylindrical Shells by Ultrasonic Guided Wave (유도초음파를 이용한 원통형 쉘의 열 라체팅 변형 탐지)

  • Joo, Young-Sang;Lee, Hyeong-Yeon;Kim, Jong-Bum;Park, Chang-Gyu;Lee, Jae-Han
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.5
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    • pp.297-305
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    • 2006
  • The thermal ratcheting deformation at the reactor baffle and upper internal structure of the liquid metal reactor (LMR) can occur due to movement of the hot sodium free surface. In in-service inspection of reactor internals of LMR, a new inspection technique should be developed for the detection of the thermal ratcheting damage. In this study, an inspection technique using ultrasonic guided wave is proposed for the detection of the thermal ratcheting damage of cylindrical vessels. A 316L stainless steel cylindrical shell specimen has been prepared. The thermal ratchet structural tests were cyclically performed by heat-up up to $550^{\circ}C$ with steep temperature gradients along the axial direction after cool-down by cooling water. Ultrasonic guided wave propagation has been characterized by analysis of dispersion curve of the stainless steel plate. The zero-order antisymmetric $A_0$ guided wave has been selected as the optimal mode for detection of the ratcheting deformation. It is confirmed that the thermal ratcheting deformation can be detected by the measurement of transit time difference of circumferentially propagated $A_0$ guided waves.

Association of Succinate Dehydrogenase and Triose Phosphate Isomerase Gene Expression with Intramuscular Fat Content in Loin Muscle of Korean (Hanwoo) Cattle (한우 등심조직 내 succinate dehydrogenase 및 triosephosphate isomerase 발현이 근내 지방함량에 미치는 영향에 관한 연구)

  • Kim, Nam-Kuk;Lee, Seung-Hwan;Lim, Da-Jeong;Yoon, Du-Hak;Lee, Chang-Soo;Kim, Oun-Hyun;Kim, Hyeong-Cheol;Oh, Sung-Jong;Hong, Seong-Koo
    • Journal of Life Science
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    • v.22 no.1
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    • pp.31-35
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    • 2012
  • In a previous study, succinate dehydrogenase (SDH) and triose phosphate isomerase (TPI) were detected by 2D gel electrophoresis as differentially expressed proteins in the longissimus thoracis muscles of cattle aged between 12 and 27 months old. In the present study, we investigated the association of SDH and TPI gene expression with intramuscular fat content in 50 Hanwoo steers. The SDH gene was expressed at a 4 times higher level in the 12 month old group than in the 27 month old group (p<0.01). A regression analysis between gene expression value and intramuscular fat content showed a negative correlation between expression of the SDH gene and intramuscular fat content (p<0.001). In contrast, the expression of the TPI gene showed no significant association with intramuscular fat content. This result suggests that the SDH gene may be a candidate marker gene for intramuscular fat content in the longissimus thoracis of Korean cattle.

Stimulation of Seed Germination of Korean Lawn grass (Zoysia japonica Steud.) by Sodium Hypochlorite Treatment (Sodium Hypochlorite 처리(處理)에 의한 한국잔디 종자(種子)의 발아촉진(發芽促進))

  • Ku, Ja Hyeong;Lee, Jong Suk;Lee, Young Bok
    • Korean Journal of Agricultural Science
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    • v.11 no.2
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    • pp.201-206
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    • 1984
  • In order to obtain an easy and effective scarification method for stimulating the seed germination of Korean lawn grass (Zoysia japonica Steud.), sodium hypochlorite (SH), which is used as a commercial bleach and a seed disinfestant, was tested as a chemical scarifier instead of potassium hydroxide (KOH). 1. Scarification with 4% SH for 2 hours followed by 8-hour water-rinse stimulated seed germination more effectively compared to generalized scarification method by KOH treatment. 2. The degree of stimulating seed gemination was different by the various water-rinsing time after SH treatment, but the optimum rinsing time was about 4 to 8 hours. 3. GA treatment after SH scarification stimulated seed germination. However, the stimulation effect of GA was not showed in non-scarified control. 4. SH treatment significantly decreased the percentage of the infection of microflora in seed samples compared to KOH treatment. 5. Under practical seed scarification conditions for stimulating germination of Korean lawn grass seed. SH may have advantages over KOH with respect to ease of preparing, securing and handling.

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Single-Dose Toxicity and Four Week Repeated-Dose Toxicity Study on Tensolin-F® (3,9-diferuloyl-6-oxopterocarpen) (Tensolin-F® (3,9-diferuloyl-6-oxopterocarpen)의 단회 독성시험 및 4주 반복투여 독성시험)

  • Kim, Keun-Su;Park, Sung-Min;Lee, Nam-Jin;Pyo, Hyeong-Bae;Chai, Hee-Yul;Jung, Yu-Ri;Lin, Chun-Mai;Kim, Sun-Hee;Lee, Hye-Young;Kang, Jong-Koo
    • Toxicological Research
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    • v.23 no.4
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    • pp.405-413
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    • 2007
  • This study was to investigate single and repeated-dose toxicities of Tensolin-$F^{(R)}$, an anti-wrinkle agent, in Sprague-Dawley (SD) rats or ICR mice. In single-dose oral toxicity study, the test materials were administered once by gavage to male and female SD rats at dose levels of 0 and 2,000 mg/kg. No dead animals and abnormal necropsy findings were found in control and Tensolin-$F^{(R)}$ treated group. Therefore, the approximate lethal dose of Tensolin-$F^{(R)}$ was considered to be higher than 2,000 mg/kg in rats. In the 4-week repeated oral toxicity study, the test material was administered once daily by gavage to male and female ICR mice at dose levels of 0, 25, 50 and 100 mg/kg/day for 4-weeks. In the results, no abnormality was observed in mortality, clinical findings, body weight changes, food and water consumptions, opthalmoscopic findings, necropsy findings, histopathological findings. In hematological analysis, there was a trend of increase in reticulocyte at male 25 mg/kg, although such changes were in normal ranges. On the other hand, there was a trend of decrease in hemoglobin at female 50, 100 mg/kg, such changes were in normal ranges. In addition, serum biochemical parameters including sodium, BUN and chloride increased at 25, 50 and 100 mg/kg. Relative organ weights of right testis, brain, lung and left epididymis were increased in 100 mg/kg groups of male rats in contrast to not change in female groups. However, these changes of relative organ weights, hematological and serum biochemical parameters were not accompanied with related signs such as histopathological changes or clinical findings. In conclusion, 4-week repeated oral dose of Tensolin-$F^{(R)}$ to ICR mice did not cause apparent toxicological change at the dose of 25, 50, 100 mg/kg body weight. Consequently the no-observed-adverse-effect level (NOAEL) for Tensolin-$F^{(R)}$ in ICR mice following gavage for at least 4-week is higher than 100 mg/kg/day.

Mass Loss and Nutrients Dynamics During the Litter Decomposition in Kwangnung Experimental Forest (광릉(光陵) 시험림(試驗林) 내(內)의 임분별(林分別) 낙엽(落葉)의 분해(分解)와 분해과정(分解過程)에 따른 영양염류(營養鹽類)의 변화(變化))

  • You, Young-Han;Namgung, Jeong;Lee, Yun-Young;Kim, Jeong-Hee;Lee, Jong-Young;Mun, Hyeong-Tae
    • Journal of Korean Society of Forest Science
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    • v.89 no.1
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    • pp.41-48
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    • 2000
  • Mass loss and dynamics of mineral nutrient during decomposition of deciduous leaves and 3 species of needles were investigated for 38 months from October in 1992 to November in 1995 in Kwangneung, Korea. After 38 months, the remaining mass of deciduous leaves, Pinus koraiensis, Pinus rigida and Abies holophylla was 16.2%, 29.8%, 33.5% and 53.9%, respectively. The decay rate (k) of deciduous leaves, Pinus koraiensis, Pinus rigida and Abies holophylla was 0.61, 0.40, 0.37, $0.21yr^{-1}$, respectively. The lowest decay rate in fir needle might be, in part, due to low N concentration. N concentration of the decomposing litter increased during the experimental period except for P. rigida. Deciduous leaves showed a short immobilization period during the early stage of decomposition, and big-cone pine and pitch pine had no immobilization period. However, there was no net N mineralization in fir litter. P increased during the experimental period for all litter. Except for deciduous leaves, there was no net mineralization period. In case of deciduous leaves, however, remaining P after 38 months was 53% of the initial P capital. Remaining cations of the decomposing litter after 38 months were lower than those of initial contents.

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Conservation and Status of Waterbirds on Sihwa Reclaimed Area (시화간척지에 도래하는 물새류 현황 및 보전 방안)

  • Lee, Si-Wan;Song, Min Jung;Lee, Hansoo;Choe, Jong In
    • Journal of Wetlands Research
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    • v.6 no.1
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    • pp.73-87
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    • 2004
  • This study was carried out on Sihwa reclaimed area from January to December in 2003. We observed total 169,351 individuals of 70 species(22 species of waders, 9 species of egrets and 5 species of gulls). Waterbird population was the largest in March(95,465 individuals) and was the smallest from April to June(less than 7,000 individuals). The most dominant species was Pintail(Anas acuta: 58,627 individuals, 34.6%) and other species were Mallards(Anas platyrhynchos: 24.5%), Common Pochards(Aythya ferina: 13.8%), Black-tailed Gulls(Larus crassirostris: 6.1%), Spotbill Ducks(Anas poecilorhyncha: 5.0%) and Greater Scaups(Aythya marila: 2.69%). Sihwa reclaimed area supported many kinds of protected species such as Chinese egrets(Egretta eulophotes), Black-faced Spoonbills(Platalea minor), Eurasian Spoonbills(Platalea leucorodia), Mute Swans(Cygnus olor), Whooper Swans(Cygnus cygnus), and Eurasian Oystercatchers(Haematopus ostralegus). They foraged at waterside of Sihwa lake and rested at reclaimed area. Particularly, Eurasian Oystercatchers bred in habitats with Salicornia herbacea and Suaeda japonica. Reclamation of mud flats and construction of roads, transmission towers and tide embankments disturbed waterbirds in breeding and foraging. We suggest that waterbirds are protected in different action plans according to their status such as breeding, passaging and wintering birds. Maintaining of waterside and swamps in Sihwa reclaimed area will be useful for breeding waterbirds. It is needed to make a protect zone for ecological connecting belt from Oeji isarea, Hyeong isarea, Eum isarea to upper channel on Sihwa lake.

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Enhancement of Insecticidal Activity of the Acetamiprid Soluble Concentrate using a Photostabilizer (광안정제를 이용한 acetamiprid 액제의 살충효과 증진)

  • Kim, Hyeong-Min;Lee, Weon-Kee;Kim, Jong-Kwan;Seok, Chang-Su;Lee, Chang-Hyuk;Yu, Yong-Man;Hwang, In-Cheon
    • The Korean Journal of Pesticide Science
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    • v.10 no.3
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    • pp.210-217
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    • 2006
  • The study was carried out to select the effective adjuvant as a photostabilizer for acetamiprid 5% SL(soluble concentrate) and to find its optimum content by using chemical and biological methods. Adjuvants used for the study were KS1 and KS2. Photodegradation test, insecticidal efficacies and residual analysis for the study were investigated. Although photodegradation rate of acetamiprid SL was decreased by addition of KS1 and KS2, the difference between KS1 and KS2 was not significant. As KS2 showed better efficacies against the cotton aphid (Aphis gossypii) and higher amount of residue on pepper than KS1, KS2 was selected as a photostabilizer for acetamiprid SL. Acetamipid SL with KS2 showed lower photodegradation rate, better efficacies against the cotton aphid (Aphis gossypii) and higher amount of residue on pepper as content of KS2 in acetamiprid SL was decreased. Therefore, it was concluded that the optimum content of KS2 was 0.1%. These results have demonstrated that the selected adjuvant could be used to enhance insecticidal activity and reduce spay dose of insecticide by protecting its photodegradation.

Enhancement of insecticidal efficacy of acetamiprid soluble concentrates using different adjuvants (서로 다른 보조제에 의한 acetamiprid 액제의 살충활성 증진효과)

  • Kim, Hyeong-Min;Lee, Weon-Kee;Kim, Jong-Kwan;Lee, Chang-Hyuk;Yu, Yong-Man;Hwang, In-Cheon
    • The Korean Journal of Pesticide Science
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    • v.8 no.4
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    • pp.325-331
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    • 2004
  • The studies were undertaken to establish optimum formulation recipes of acetamipid 4% SL(soluble concentrate) using different adjuvants and to evaluate enhanced control effect on target insect pests by adjuvants. Adjuvants for the studies used were SS(Sodium alkylcarboxylate) and PE(Polyoxyethylene alkyl ether). After the fundamental recipe for SL being established by using co-solvent for stability at low temperature, four types of SL were formulated. The physical properties and insecticidal efficacies of the tested SL formulations were investigated. Surface tension of SL1 without adjuvant was highly decreased from 44 dyne/cm to 34 dyne/cm by addition of adjuvants. SL4 using mixed adjuvant showed the lowest contact angle. Efficacies of SL1 without adjuvant against the palm thrips (Thrips palmi) and the cotton aphid (Aphis gossypii) on cucumber were increased by adding adjuvants. SL4 using mixed adjuvant showed higher efficacy than SL2 and SL3 using single adjuvant. These results have demonstrated that the selected adjuvants could be used to enhance insecticide efficacy and reduce spray dose of insecticide.

Effect of 18 Irradiation on Neurotransmitters in the Brains of Goldfish Carassius auratus (18 방사성동위원소 피폭에 의한 금붕어(Carassius auratus)뇌의 신경전달물질 변화)

  • Park, Nam-Gyu;Go, Hye-Jin;Kim, Gun-Do;Lee, Jong-Kyu;Kil, Sang-Hyeong;Lee, Byung-Woo
    • Journal of Life Science
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    • v.22 no.8
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    • pp.1046-1051
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    • 2012
  • In order to investigate the changes in bioactive materials induced in goldfish brains by $^{18}F$ irradiation, the variations in the neurotransmitter levels in the whole brain were studied. The distance between the goldfish and 580 mCi of $^{18}F$ was about 4 cm, and the exposure lasted for 4 hrs. The absorption level calculated based on the distance, exposure time, and half-life of $^{18}F$ was approximately 2 Gy. After sacrifice by $^{18}F$ irradiation or untreated conditions, ten brains were dissected or immediately frozen, respectively. The tissues were extracted in acetic acid. After lyophilization, the samples were dissolved in distilled water and were further purified on a reverse-phase HPLC column. There were no differences in the intensities of the bioactive materials between $^{18}F$-exposed goldfish and control goldfish, while the only peak corresponded to 13 min, which indicated a significant increase in the irradiated brains. Our analysis has found that this compound is tryptophan. This result suggests that $^{18}F$ leads to changes in a classical neurotransmitter, tryptophan, in both the brains of control goldfish and goldfish contaminated by irradiation.

Detection of Gnathostoma spinigerum Third-Stage Larvae in Snakeheads Purchased from a Central Part of Myanmar

  • Jung, Bong-Kwang;Lee, Jin-Ju;Pyo, Kyoung-Ho;Kim, Hyeong-Jin;Jeong, Hoo-Gn;Yoon, Cheong-Ha;Lee, Soon-Hyung;Shin, Eun-Hee;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.46 no.4
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    • pp.285-288
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    • 2008
  • To examine the infection status of freshwater fish with Gnathostoma spp. larvae in Myanmar, we purchased 15 snakeheads, Channa striatus, from a local market in a suburban area of Naypyidaw, the new capital city. Two larval gnathostomes were collected using an artificial digestion technique, and observed by a light microscope and a scanning electron microscope. The size of an intact larva was 2.65 mm long and 0.32 mm wide. The characteristic morphology of the larvae included the presence of a long esophagus (0.80 mm long), 2 pairs of cervical sacs (0.43 mm long), and a characteristic head bulb with 4 rows of hooklets. The number of hooklets in the 1st, 2nd, 3rd, and 4th row was 45, 48, 50, and 52, respectively. Based on these morphological characters, the larvae were identified as the advanced 3rd-stage larvae of Gnathostoma spinigerum. This is the first report of detection of G. spinigerum 3rd-stage larvae in the central part of Myanmar. Our study suggests that intake of raw meat of snakehead fish in Myanmar may result in human gnathostomiasis.