• 제목/요약/키워드: Fiber Sources

검색결과 339건 처리시간 0.035초

방사성 오염도 측정을 위한 광섬유 검출기 제작 (Fabrication of Fiber-optics Detector for Measuring Radioactive Waste)

  • 김정호;주관식
    • 전기전자학회논문지
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    • 제19권3호
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    • pp.282-287
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    • 2015
  • 본 연구에서는 연구에서는 Ce:GAGG 섬광체, 광섬유 그리고 광전자증배관을 이용하여 광섬유 검출기를 제작하였다. 섬광체의 단결정 크기는 MCNPX 코드를 이용하여 섬광체 깊이에 따른 감마선 계수효율을 전산모사하여 $3{\times}3{\times}20mm^3$로 설정하였다. 제작된 검출기는 표준 감마선원인 $^{137}Cs$$^{133}Ba$을 이용하여 세기의 따른 선형성 평가와 거리 변화에 따른 계수량 변화 측정을 하였다. 그 결과 추세선식 R-square 값이 0.99741로 매우 좋은 응답선형성을 보였고, 거리에 따른 검출 특성 또한 MCNPX값과 비교하였을 때 2% 이하로 좋은 검출특성을 보였다. 또한 단일선원과 혼합선원에서의 감마선 에너지 분광 결과 $^{137}Cs$은 662keV에서 그리고 $^{133}Ba$은 356keV에서 감마선 에너지 피크를 확인하였다. 광섬유 검출기를 사용한다면 작업자의 작업시간과 피폭을 줄여줄 것으로 보인다.

AMINO ACID DIGESTIBILITY AS AFFECTED BY VARIOUS FIBER SOURCES AND LEVELS 2. THE RELATIONSHIP BETWEEN FIBER LEVELS AND AMINO ACIDS DIGESTIBILITY

  • Nongyao, A.;Han, In K.;Choi, Yun J.;Lee, N.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제3권4호
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    • pp.353-361
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    • 1990
  • A number of correlation and regression analyses were performed on data from apparent and true digestibility of amino acids at ileal and fecal level with finishing pigs, in order to investigate whether these amino acid digestibilities could be predicted with certainly degree on their fiber fractions content (chemical analysis). The data comprised 16 diets varying in 4 levels of crude fiber and from 4 fiber sources. The relationships between fiber fractions including crude fiber (CF), NDF, ADF lignin and cellulose contents on apparent and true digestibility of almost all amino acids in both ileal and fecal level were negative, except glutamine at fecal level. In apparent digestibility at ileal level, the correlations of fiber fractions were moderate (r of NDF = 0.53 to 0.63; ADF, 0.50 to 0.77; cellulose, 0.50 to 0.75), with an exception of CF content was relatively high (r of 0.58 to 0.81). The correlations to true digestibility of amino acids were weaker. In case of at fecal level, the higher correlation (negative) was found with NDF than CF content. Estimations of amino acids digestibility were performed using regression equation. The data showed that apparent digestibility of amino acids could be estimated for almost amino acids except arginine, threonine, valine and tyrosine at fecal level and phenylalaine, valine and glycine at ileal level. The best prediction at ileal and fecal level ($r^2=0.55-0.77$ and 0.52-0.76), respectively was obtained with NDF content. Prediction for true digestibility of amino acids, none of fiber fractions could be estimated for arginine, leucine and valine at all collection levels. At ileal level, CF could be used for most of amino acids except phenylalanine, glycine and praline; cellulose, only for lysine and methionine and NDF, only for proline. At fecal level, glutamine digestibility could be estimated only from CF and ADF content. The best predictor at ileal level was ADF content whereas at fecal level was NDF content. These results indicate that lignin content could not be used as predictor for all amino acids at both levels neither in apparent nor true digestibility.

식이섬유가 무기질의 생체이용에 미치는 영향 (Effect of Dietary Fiber on Mineral Bioavailability)

  • 최면
    • 한국식품위생안전성학회지
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    • 제7권4호
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    • pp.165-172
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    • 1992
  • Among the nutrients of biological importance, minerals are of particular interest in human nutrition because the range of adequate intake is so narrow. As the results of a series of interaction experiments between dietary fiber sources and minerals, there are many inconsistencies in the experimental data regarding the effect of dietary fibers on mineral bioavailability. the mechanism by which dietary fiber might influence mineral absorption is related to its physicochemical properties. These properties involve the ability of dietary fiber to (1) act as a weak cation exchanger, (2) decrease transit time, (3) dilute mineral concentration by increasing fecal bulk and (4) resist digestion in the large bowel. Regardless of the large number of human and animal studies available, a carful review of these publications dose not provide the answer as to whether the adverse effect of dietary fibers on mineral absorption is the fiber itself or some associated dietary factors( e.g. phytate, oxalate, ascorbate, citrate and protein, mineral-mineral interaction, etc) that are responsible for this action. As a result of the complexity of interaction that may take place between minerals. dietary fiber, and other component of food ; it becomes very difficult to blame fiber alone as a negative factor of mineral nutrition. We absolutely need more research with advanced tools rather than metabolic balance study.

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Party-wear Consumers' Information Sources and Clothing Evaluative Criteria

  • Park, Hyun-Mi;Cho, Yun-Jin;Lee, Yu-Ri
    • International Journal of Costume and Fashion
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    • 제9권2호
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    • pp.67-78
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    • 2009
  • The volume of the party wear market is gradually growing in the Korean fashion market. The study attempted to examine psychological clothing benefits as the criteria for market segmentation, and identify differences in information sources. and clothing evaluative criteria in each segmentated market. The summary of the key findings are as follows. Three segments were identified by psychological clothing benefits: pleasurably self-expressing group, fashion-seeking group, and indifferent group. The differences in search information sources between the classified groups were identified The fashion-seeking group had a higher mean score on mass media. The pleasurably self-expressing group had higher scores on advice from friends, colleagues, or companions. The differences in evaluative criteria between the classified groups were also identified. Among the evaluative criteria, the splendid boldness and polished silhouette criteria showed a marginal difference between each group. This study can contribute as a cornerstone for future studies on party wear and market strategies.

연신조건이 PTT 섬유의 배향에 미치는 영향(II) (Effect on the Orientation of Poly(trimethylene terephthalate) Fibers in Drawing Conditions(II))

  • Kang, Seok-Jin;Kim, Kyoung-Hou;Cho, Hyun-Hok
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 가을 학술발표회 논문집
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    • pp.211-212
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    • 2003
  • Since Poly(trimethylene terephthalate)(PTT)'s synthetic method was first reported in 1941 by Whinfield et at. [l], many scientifical studies have worked for commercializing. Nevertheless, it was never commercialized because of many unstable sources. Like report of preceeding researchers, PTT was known to us that it had unique crystal structure such as coiled spring due to conformation of tggt. (omitted)

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Development of optical fiber source to apply OCT systems

  • 엄태중;;유봉안;신우진;이영락;지상윤;고도경;김창석;정은주
    • 한국광학회:학술대회논문집
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    • 한국광학회 2008년도 동계학술발표회 논문집
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    • pp.305-306
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    • 2008
  • We have developed several types of optical sources for OCT applications. A high nonlinear PCF with end sealing and a short pulse laser were used to improve of OCT resolution. Additionally, an wavelength sept fiber laser was also developed for frequency-domain OCT.

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Fiber Optic Engine for Full Color Mobile Display

  • Arabi, H.;An, S.;Oh, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.400-401
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    • 2009
  • In this paper we report a micro projector including of RGB sources, a $3{\times}1$ Fiber Optic Color Synthesizer (FOCS), and a two dimensional micro mechanical scanning mirror. We further report a modifier micro collimator which can enhance the resolution of the screened image.

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한국인의 식이섬유 섭취 실태 (Dietary Fiber Intake of Korean)

  • 이혜성
    • 한국식품영양과학회지
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    • 제26권3호
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    • pp.540-548
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    • 1997
  • According to the data published in 1990s on the intake of dietary fiber(DF) of Korean, DF intake of Korean has been gradually decreasing in the last two decades. Mean daily intake of DF in 1990s is estimated to be in the rage of 17-20g per capita and over seventy five percent of the subjects examined appeared to consume DF less than 20g per day. The major food sources of Df in Korean diet include cereals, vegetables, fruits, seaweeds and seasonings. The present level of DF intake of Korean is lower than the tentatively recommended minimum intake of DF. It is predicted that, if the present trend of change on food consumption pattern is maintained, the gradual increases in the incidence of chronic degenerative diseases will be continuing. Therefore, the beneficial effects of DF on health care and disease control should be emphasized through the nutritional education and high level consumption of DF needs to be strongly recommended in the dietary guideline. In order to raise the daily consumption of DF, more whole grain cereals need to be used as a part of staple and more frequent intake of legumes and seaweeds is required as well as the development of high-fiber diet recipes and natural high-fiber products.

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압출성형에 의한 식물세포벽의 수용화 (Solubilization of Plant Cell Walls by Extrusion)

  • 황재관;김종태;홍석인;김철진
    • 한국식품영양과학회지
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    • 제23권2호
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    • pp.358-370
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    • 1994
  • Plant cell walls consist of a variety of chemical constituents such as cellulose, humicelluloses, pertins, lignin, glycoproteins, etc. These components are strongly linked through hydrogen , covalent, ionic and hydrophobic bondings, which thus confers the self-protection capability on plants. Some processing by-products (hulls, brans, pomaces) of cereal, fruits and vegetables are very limited in further utilization due to their compact structural rigidity. In view of the fact that the plant cell walls are essentially composed of dietary fiber components , solubilization of the strong intermolecular linkage s can contribute to increasing the soluble dietary fiber content and thus diversifying the functional and physiological role of plant cell walls as dietary fiber sources. This article reviews the chemical constituents of cereals, fruits & vegetables and brown seaweeds with reference to their intermoleuclar linkages. An particular emphasis will be placed on the solubilizing phenomena of rigid plant cell walls by extrusion and the resulting change of functional properties. It is suggested that underutilized food resources, typically exemplified by various food processing by-products and surplus seaweeds, can be successfully modified toward improved functional performance by extrusion.

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L-band Power Enhancement through the reinsertion of backward ASE filtered by a C/L-band coupler

  • Kim Seung Taek;Gang Seong Bok;Jeong Hun;Lee Gyeong Gyun;Gang Hui Seok;Jo Yeong Jun
    • 한국광학회:학술대회논문집
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    • 한국광학회 2003년도 하계학술발표회
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    • pp.20-21
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    • 2003
  • Erbium doped fiber (EDF) sources are useful devices for characterization of optical components for wavelength division multiplexing (WDM) fiber optic communication system. Therefore, there are many efforts to extend the bandwidth and to increase the power of the light source. Especially, L-band ASE source uses the low inversion state of EDF. It makes the power efficiency very low and needs a lot of fiber as several times as the fiber needed in C-band ASE generation. (omitted)

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