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The Study About Attenuation of Scatter Ray According to Distance Inverse Square Law at General Projection (일반촬영 시 거리역자승법칙에 따른 산란선 감약에 관한 연구)

  • Jeon, Min-Cheol;Lim, Hyun-Soo;Han, Man-Seok
    • Journal of radiological science and technology
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    • v.34 no.3
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    • pp.183-188
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    • 2011
  • We studied the optimal location where the radiation dose of radiological technologists is minimally measured. The measured scatter dose has been compared with the distance inverse square law. We measured the primary X-ray with different tube conditions (60, 70, 81 and 90 kVp) and distances (60, 120 and 180 cm). The scatter ray has been measured with various locations (42.5, 52.4 and 62.4 cm for front and back side, 0 to 60 cm with 10 cm interval for left and right side). The results of this study showed that the dose of primary X-ray was attenuated to 20.52 (27.20%), 28.58 (25.20%), 38.82 (26.32%) and 48.20 mR (26.27%) for each tube voltages at 120 cm. In addition, The dose were 7.06 (8.91%), 9.90 (8.73%), 13.64 (9.25%) and 16.60 mR (9.05%) at 180 cm. As for the scatter in front and back side, the attenuated dose were 0.15 mR (23.09%) and 0.15 mR (22.08%) at 120 cm, and 0.07 mR (10.43%) and 0.06 mR (8.83%) at 180 cm. Scatter was decreased in third quadrant. Therefore, it is recommended that radiological technologists should keep long distance from the object.

Effects of Ganoderma lucidum Extract on Production of Fatty Acids by Rhodotorula glutinis (영지 열수추출물이 Rhodotorula glutinis의 지방산 생성에 미치는 영향)

  • Joo, Hyun-Kyu;Park, Woo-Chul;Sa, Tong-Min;Lee, Young-Tack;Yun, Choong-Hyo
    • Korean Journal of Food Science and Technology
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    • v.29 no.1
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    • pp.120-125
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    • 1997
  • Rhodotorula glutinis was inoculated in the medium containing 0 ($S_0$), 0.01 ($S_1$), 0.1 ($S_2$) and 1.0% ($S_3$) Ganodoma lucidum extract and incubated in a shaking incubator at $30^{\circ}C$ for 8 days and the cell growth, sugarity, lipid content, and fatty acid composition were measured to investigate the effects of G. lucidum extract on the growth and biosynthesis of fatty acids by oleaginous yeast, Rhodotorula glutinis. After the 8 day incubation, the cell growth of $S_1,\;S_2\;and\;S_3$ increased 1.6, 1.7 and 2.1 times, respectively, than that of $S_0$. Sugar consumption of incubating medium was decreased but the crude lipid content in R. glutinis was increased with increase of the amount of G. Lucidum extract. Myristic, palmitic, stearic, oleic and linoleic acids were identified by GC as the major fatty acids in the crude lipid produced by R. glutinis and the content of unsaturated fatty acids (38.6 mg/g) was greater than that of saturated fatty acids (22.3 mg/g). As the G. lucidum extract concentration increased, fatty acids contents were increased except myristic acid, and the most increase occurred at the addition of 0.1% while they were considerably decreased in the case of the addition of 1.0% G. lucidum extract.

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Analysis of Aerodynamic Efficiencies of Fighter Aircraft in Close Formation Flight Using a Panel Method (패널법을 사용한 근접 편대비행 전투기 공력효율성 분석)

  • Kim, Jaemuk;Han, Cheolhuei
    • Journal of Institute of Convergence Technology
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    • v.11 no.1
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    • pp.29-32
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    • 2021
  • 편대비행 항공기들은 선행항공기에서 발생시킨 후류의 영향으로 후행항공기의 공력효율이 증가하는 것으로 잘 알려져 있다. 비점성 비회전 유동장에 관한 연속방정식을 지배방정식으로 사용하는 패널법은 비교적 빠른 시간 이내에 항공기의 공력특성 변화를 계산할 수 있는 장점이 있다. 본 연구에서는 편대비행 항공기들 사이의 항공기들 사이의 흐름방향 거리는 스팬길이의 2.5배로 위치시키고, 수평상대거리는 스팬길이의 -0.4~0.3배로, 수직상대거리는 스팬길이의 -0.25, -0.15.0.15.0.25배로 변화시키며 계산을 수행했다. 연구결과 선행항공기와 후행항공기의 수평상대거리 변화의 경우 주날개들이 안쪽으로 겹침이 발생하고, 수직 상대거리가 가까울수록 더 큰 공력성능 향상을 얻을 수 있었다. 편대비행 하는 후행항공기의 공력성능 향상은 선행 항공기로부터 발생한 익단 와류의 올려흐름 영향에 기인한 것이다. 선행항공기로부터 발생한 익단와류는 후행항공기의 모멘트 특성을 변화시켜 비행안정성에 영향을 미치게 된다. 향후 연구에서는 선행항공기로부터 발생한 와의 영향이 후행항공기의 모멘트 특성에 미치는 영향을 연구 할 것이다.

A Follow-up Survey of Mothers' Antenatal Breast-feeding Plans (임신시 모유 수유 계획의 실천에 대한 추적 관찰)

  • Kim, Hae Soon;Seo, Jeong Wan;Kim, Yong Joo;Lee, Kee Hyoung;Kim, Jae Young;Ko, Jae Sung;Bae, Sun Hwan;Park, Hye Sook
    • Clinical and Experimental Pediatrics
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    • v.46 no.7
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    • pp.635-641
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    • 2003
  • Purpose : To investigate the success rate and factors that influence breast-feeding among women having antenatal breast-feeding plans. Methods : Questionnaires included items on success in breast-feeding, reasons for failure and perinatal factors. It was done by telephone calls to 152 randomly selected women having antenatal breast-feeding plans at 4 months after delivery. The questionnaires were analysed by bivariate ${\chi}^2$-analysis. Results : The breast-feeding rate for the first four months among women having antenatal breast-feeding plans was 37.5%. The major reason for breast-feeding failure was insufficient amount of breast milk(66.3%). The breast-feeding rate was 2.3(95% CI 1.15-4.62) times higher in women having antenatal breast-feeding plans for longer than 4 months(P<0.05), but maternal age, breast-feeding for previous baby, person advocating breast-feeding, and family size were not significant factors of success in breast-feeding. The breast-feeding rate of graduates of college was 0.43(95% CI 0.21-0.86) times lower than that of graduates of high school. The breast-feeding rate of employed mothers was 0.37(95% CI 0.17-0.83) times lower than that of housewives(P<0.05). Maternal disease, smoking, alcohol drinking, and understanding and knowledge about breast-feeding were not significant determinant factors of success in breast-feeding. Breast-feeding rate of infant born at local obstetric clinics was 3.97(95% CI 11-14.23) times higher than that of infant at general hospital(P<0.05). Conclusion : To increase the breast-feeding, medical personnel should educate mothers on problems during breast-feeding. Hospital polices that facilitate breast-feeding such as rooming-in must be promoted. For employed mothers, strategies for breast-feeding within companies must be encouraged.

체외성숙 배지에 amino acid 첨가가 배발달율과 세포수에 미치는 영향

  • 이재협;박용수;최수호;변명대;박흠대
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.115-115
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    • 2003
  • 아미노산은 수정란의 체외생산에 있어서 배발달에 유효하게 작용한다. 이러한 이유로 체외배양 단계에 아미노산 첨가에 관한 보고는 많지만, 체외성숙 단계에서의 아미노산 효과와 관련된 보고는 소수이다. 본 실험에서는 먼저 체외성숙 배지에 NEAA와 EAA군들의 첨가 농도가 PB 출현율, 배발달율 그리고 생산된 배반포의 세포수에 미치는 영향과 더불어 새로운 아미노산원으로 LAH의 효과를 검토하였다. 체외성숙을 위한 난포란은 도축 한우 난소에서 2-8mm의 가시난포로부터 회수하였다. 체외성숙용 배지는 10% FBS가 첨가된 CRlaa 용액을 사용하였고, 실험1에서는 NEAA와 EAA(20$\mu l$/ml)군을 각각 $\times$l (NEAA:10$\mu l$/ml, EAA:20$\mu l$/ml), $\times$2 및 $\times$4를, 실험2에서는 LAH를 각각 1, 5 및 10 mg/ml를 첨가하였다. 체외수정은 fer-TALP 용액을, 체외배양은 CRlaa 용액을 배양 2일째까지는 0.3% BSA를, 그 이후에는 10% FBS와 난관상피세포를 첨가하여 사용하였다. 그리고 배양 8일째 확장배반포의 세포수를 조사하기 위하여 이중형광염색을 실시하였다. 통계분석은 $X^2$-test를 이용하였다. 실험 1에서 NEAA와 EAA 첨가 농도에 따른 PB 출현율은 $\times$l 첨가군(46.6%)이 대조군(29.9%)에 비하여 유의적으로 높았다. 수정을, 8세포기 및 배반포까지 발달율은 비슷한 경향이었으나, $\times$l 첨가군이 가장 높았다. 한편 ICM 세포수가 아미노산 첨가 농도의 높을수록 증가하는 경향이었고, 특히 $\times$4 첨가군($23.9 \mu 3.9$)이 대조군($14.8 \mu 2.5$)에 비하여 유의적(P<0.05)으로 높았다. 실험 2에서 LAH 첨가에 따른 핵성숙율은 5mg 첨가군, 배반포까지 발달율은 1mg 첨가군(25.9%)이 각각 가장 높았다. 배양 8일째 배반포의 세포수에 있어서 총세포수와 TE 세포수는 차이가 없었으나, ICM 세포수가 l0mg 첨가군에서 가장 높았다. 본 실험 결과에서 체외성숙 배지에 NEAA와 EAA 첨가가 배발달율에는 효과가 없었지만, 첨가농도의 증가에 따라 ICM 세포수가 증가하였다. 한편 체외성숙 배지에 LAH 첨가는 첨가 농도가 높을수록 배발달율은 낮았지만 ICM 세포수는 증가하였다.

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Changes in Color of Spinach Leaves by Blanching (데치기에 따른 시금치 잎의 변색)

  • 이애랑
    • Korean journal of food and cookery science
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    • v.8 no.1
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    • pp.15-20
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    • 1992
  • The changes in color of spinach leaves upon blanching in boiling water and by microwave oven were investigated. The noticible changes in color of leaves were observed above $70^{\circ}C$. The values of L (lightness), a (redness) and b (yellowness) were decreased upon blanching. The value of the under surface of leaves was decreased by 2~3 times compared to that of the upper surface. The noticible color changes occured from 15 sec and the absorbance at 432 nm of water increased rapidly from 2 min of blanching in boiling water. Salt (0.5 and 0.9%) decreased the absorbance at 432 nm of water. The changes of L and b of the under surface of leaves upon heating with a microwave oven were less compared with those in boiling water. Based on the color differences of leaves upon blanching in boiling water, the optimum ratio of spinach to water was 1:4 or 1:5.

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Asymbiotic germination and seedling growth of Calanthe striata f. sieboldii Decne. ex Regel (금새우난초(Calanthe striata f. sieboldii Decne. ex Regel)종자의 비공생 발아 및 신초증식)

  • Bae, Kee Hwa;Kim, Soo-Young
    • Journal of Plant Biotechnology
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    • v.42 no.3
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    • pp.239-244
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    • 2015
  • Calanthe striata f. sieboldii Decne. ex Regel is a terrestrial orchid with beautiful flowers arranged in racemose inflorescences. This species is threatened due to over-collection and loss of suitable habitats. Asymbiotic germination is useful in the conservation efforts to re-establish plants in the wild, and for commercial propagation. In this study, we investigate the effects of sodium hypochlorite (NaOCl), three types of culture media (Phytomax Orchid Maintenance - POM, Seed Germination Maintenance - SGM, and Murashige and Skoog 1962 - MS), and plant growth regulators on embryo swelling, protocorm formation, and embryo diameter of C. striata f. sieboldii. Treatment with 1% NaOCl for 30 min greatly enhanced embryo swelling (28.3%), embryo diameter ($205.8{\mu}m$), and embryo protocorm formation (54.8%) compared to seeds without NaOCl treatment (embryo swelling 8.5%, embryo diameter $14.6{\mu}m$, and protocorm formation 13.4%) on POM medium. Protocorm formation on POM medium supplemented with 1.0 mg/L N6-benzyladenine (BA) (95.6%) was better than the control (54.5%). Additionally, the effects of activated charcoal (AC) and sucrose on seedling growth in in vitro culture were examined. The protocorm converted into healthy plants with well-developed shoot primordia on the POM medium with AC and sucrose. The most suitable conditions for seedling growth after 10 weeks of culture were the POM medium with AC or sucrose. These results show effective asymbiotic seed germination and in vitro seedling growth of C. striata f. sieboldii.

The Result of Oral Health Care on Primary School Children Using Dental Caries Activity Test (일부 초등학생의 치아우식활성검사를 이용한 계속구강건강관리 효과)

  • Son, Eun-Yung;Choi, Moon-Sil
    • Journal of dental hygiene science
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    • v.12 no.2
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    • pp.93-102
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    • 2012
  • The purpose of this study was to evaluate the effectiveness of oral health care including some of dental caries activity test on dental clinics of regular visiting on primary school children. The dental surveys and initial caries control and some of dental caries activity test (Alban's, Lactobacillius, S'mutans, un-stimulation saliva test)were performed by trained dental hygienists with dentist from on 6 to 13 years old patients of S dental hospital in Gwangju Metropolitan Cities. The sample size of 39 children (18 in oral health care group, 21 in control group ) and accepted to their parents. The results of caries activity test score(Alban's and Lactobacillius test)were reduced 1.4 to 1.6 times in oral health care group(OHCG). Oral Hygiene Simplified Index of OHCG was reduced 1.6 times during six months and 1 year. DMFT index of OHCG was reduced 1.4 times more than Control Group(CG) after 1 year. DT index of OHCG was reduced 12 times more than Control Group(CG) after 1 year. Dental health capacity of the first perment molar of OHCG was reduced 1.02 times more than CG after 1 year. From the above results, long life related incremental oral health care system has reinforced to primary school children in dental clinic with oral health professional teams.

Multi-secondary Somatic Embryogenesis and Plant Regeneration from Hypocotyl Cultures of Alfalfa (Medicago sativa L.) (알팔파의 하배축으로부터 다량의 이차 체세포배 발생과 식물체 재분화)

  • Won, S.H.;Lee, B.H.;Kim, K.Y.;Lee, H.S.;Lee, H.J.;Jo, J.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.19 no.3
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    • pp.273-280
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    • 1999
  • Hypocotyl explants of Medicago saliva cv. Vernal were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of growth regulators. After six weeks of culture, somatic embryos were formed from calli on MS medium containing $4mg/{\ell}$ 2,4-D and $0.1mg/{\ell}$ kinetin, or $4mg/{\ell}$ 2,4-D and $0.5mg/{\ell}$ kinetin. The mature somatic embryos were developed to plantlets when subcultured on MS basal medium. In order to obtain secondary somatic embryogenic calli, cotyledon of regenerated plantlets were cultured on a callus induction medium. Embryogenic calli were formed on MS medium containing $4mg/{\ell}$ 2,4-D alone. For induction and development of secondary somatic embryogenesis, the embryogenic calli were transferred to MS basal medium containing either 2,4-D or NAA. Multi-secondary somatic embryogenesis was the most effective on MS basal medium with $0.1mg/{\ell}$ 2,4-D. The rate of secondary somatic embryo formation of regenerated plants was 18 times higher than that of seed grown plants. The mature secondary somatic embryo were germinated into plantlets on MS basal medium after six weeks of culture.

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흑마늘의 이화학적 성분 및 항산화활성

  • Seong, Nak-Ju
    • Food preservation and processing industry
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    • v.7 no.1
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    • pp.45-53
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    • 2008
  • 흑마늘의 이화학적 성분의 변화 및 항산화 활성에 대한 연구를 분석한 결과, 흑마늘의 색은 제조공정을 거치면서 L, a 및 b값이 모두 감소하였는데 내부색의 경우 가공 초기에 크게 감소하였다. 수분은 가공 중 계속해서 감소하였고, pH도 점차 산성화되어 가공이 끝난 시료에서 pH $4.22{\pm}0.02$였다. 총 페놀 화합물과 플라보노이드는 1단계시료에 비해 최종단계에서 각각 약 1.9배, 2.6배 증가하였다. Total pyruvate와 thiosulfinate도 비슷한 패턴으로 각각 약 1.6배, 5.8배 증가하였다. 유리당 중 가장 함량이 높은 fructose는 1단계에서는 $1,403.03{\pm}6.24\;mg/100\;g$ 였던 것이 4단계에서는 $2,454.45{\pm}4.20\;mg/100\;g$으로 증가하였으나, 반면에 이당류인 sucrose와 maltose는 흑마늘의 숙성과 더불어 서서히 감소하는 경향이다. 흑마늘의 구성아미노산은 glutamic acid의 함량이 가장 많았고, 다음으로 proline과 aspartic acid였으며, 유리아미노산은 taurine, homocysteine 및 $\delta$-hydroxylysine은 1단계 혹은 2단계 시료에서는 검출되지 않았으나, 2단계 혹은 3단계 이후시료에서 미량 검출되었다. 흑마늘 가공중 물추출물과 에탄올 추출물의 DPPH에 대한 전자공여능은 숙성이 진행될수록, 추출물의 첨가 농도를 높일수록 점차 증가하여 4단계 시료의 $1,000\;{\mu}g/mL$ 농도에서 에탄올 추출물은 $45.63{\pm}0.43%$, 물추출물은 $67.40{\pm}0.21%$로 시험된 시료 중 가장 높은 활성을 보였다. 환원력은 100 및 $500\;{\mu}g/mL$ 농도에서 1, 2단계 시료를 제외한 모든 시료에서 물추출물이 에탄올 추출물 보다 높은 활성을 보였다.

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