• 제목/요약/키워드: RD

검색결과 6,515건 처리시간 0.034초

모재의 방향성에 따른 마찰교반용접 판재의 성형성에 관한 실험적 연구 (Experimental Formability Investigation for FSW Sheets with Respect to Base Material's Directional Combination)

  • 김대용;이원오;김준형;;정관수
    • 소성∙가공
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    • 제18권1호
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    • pp.73-79
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    • 2009
  • In order to investigate the formability of friction stir welded(FSW) tailor welded blanks(TWB) with respect to the base material's directional combination, aluminum alloy AA6111-T4 sheets were welded with three different conjoining types: RD-RD, TD-RD and TD-TD. Here, RD and TD represent rolling and transverse directions, respectively. For experimental formability study, three tests with gradual complexity were performed: the simple tension test with various weld line directions for uni-axial elongation, the hemisphere dome stretching test for biaxial stretching and the cylindrical cup deep drawing test. As a result, all three forming tests showed that RD-RD type samples exhibited the best formability, while TD-TD type sheets showed the least formability performance.

Production of Ginsenoside Rd from Ginsenoside Rc by ${\alpha}-{\small{L}}$-Arabinofuranosidase from Caldicellulosiruptor saccharolyticus

  • Shin, Kyung-Chul;Lee, Gi-Woong;Oh, Deok-Kun
    • Journal of Microbiology and Biotechnology
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    • 제23권4호
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    • pp.483-488
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    • 2013
  • Ginsenoside Rd was produced from ginsenoside Rc using a thermostable recombinant ${\alpha}-{\small{L}}$-arabinofuranosidase from Caldicellulosiruptor saccharolyticus. The optimal reaction conditions for the production of ginsenoside Rd from Rc were pH 5.5, $80^{\circ}C$, 227 U enzyme/ml, and 8.0 g/l ginsenoside Rc in the presence of 30% (v/v) n-hexane. Under these conditions, the enzyme produced 7.0 g/l ginsenoside Rd after 30 min, with a molar yield of 100% and a productivity of 14 g $l^{-1}\;h^{-1}$. The conversion yield and productivity of ginsenoside Rd are the highest reported thus far among enzymatic transformations.

An Iterative MUSIC-Based DOA Estimation System Using Antenna Direction Control for GNSS Interference

  • Seo, Seungwoo;Park, Youngbum;Song, Kiwon
    • Journal of Positioning, Navigation, and Timing
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    • 제9권4호
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    • pp.367-378
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    • 2020
  • This paper introduces the development of the iterative multiple signal classification (MUSIC)-based direction-of-arrival (DOA) estimation system using a rotator that can control the direction of antenna for the global navigation satellite system (GNSS) interference. The system calculates the spatial spectrum according to the noise eigenvector of all dimensions to measure the number of signals (NOS). Also, to detect the false peak, the system adjusts the array antenna's direction and checks the change's peak angles. The phase delay and gain correction values for system calibration are calculated in consideration of the chamber's structure and the characteristics of radio waves. The developed system estimated DOAs of interferences located about 1km away. The field test results show that the developed system can estimate the DOA without NOS information and detect the false peak even though the inter-element spacing is longer than the half-wavelength of the interference.

뇌경색 발병후 병발된 만성 애역(Chronic hiccup)의 뜸치료 1례 (A Case of Moxibustion Therapy on Chronic Hiccups after Cerebral Infarction)

  • 전우현;김진석;홍종희;홍상선;박석규;김진성;류봉하;류기원;박재우
    • 대한한방내과학회지
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    • 제22권1호
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    • pp.109-112
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    • 2001
  • Hiccups, also known as singultus, are spasmodic involuntary contractions of respiratory muscles that shorten respiration. The characteristic sound is caused by rapid closure of the glottis. In oriental medicine, the mechanism of hiccups is "reversed flow of Ki". Hiccups have been associated with neoplasm, infections, seizures, diabetes. renal failure, alcohol ingestion, various drugs, and ischemic events of the myocardium or central nervous system. We present a case of chronic hiccups after cerebral infarction that was successfully treated using moxibustion therapy.

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The Correlation between Deviation Indexes of Ryodoraku and Acute Stress in Patients with Functional Dyspepsia

  • Eom, Guk-Hyeon;Lee, Joon-Suk;Kim, Hyun-Kyung;Lee, Seon-Young;Hur, Won-Young;Kim, So-Yeon;Kim, Jin-Sung;Ryu, Bong-Ha;Yoon, Sang-Hyub
    • 대한한의학회지
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    • 제27권4호
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    • pp.142-149
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    • 2006
  • Objectives : The aim of this study was to investigate the relationship between stress type and Ryodoraku score (RS) in patients with functional dyspepsia. Methods : 92 (30 male, 62 female) patients with functional dyspepsia were included in this study. Degree of stress was evaluated by GARS and BEPSI scale which can assess acute and chronic stress, respectively. RS of the patients was measured, and mean, sum of gaps and standard deviation (SD) in their RS were taken. First, patients were divided into two groups by sex, and by mean RS $40{\mu}A$ (above and below). GARS and BEPSI scale of each group was compared. Second, correlation between stress scales (GARS and BEPSI) and variation indexes of RS (sum of gaps and SD) was examined. Result : 1. The mean RS is higher in male patients than in female ones. 2. No significant difference was noted in GARS and BEPSI scale associated with above end below the mean $40{\mu}A$ RS. 3. The sum of gaps and SD of RS has significant correlation with GARS scale but not with BEPSI scale. Conclusions : These results suggest that the sum of gaps and SD of RS are associated with acute stress in patients with functional dyspepsia. Thus, it is thought that RS can be useful in assessing acute stress in patients with functional dyspepsia.

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Rhizopus japonicus의 효소(酵素)에 의한 인삼(人蔘) 사포닌의 선택적(選擇的) 전환(轉換) (Specific Conversion of Ginseng Saponin by the Enzyme of Rhizopus japonicus)

  • 김상달;서정훈
    • 한국균학회지
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    • 제14권3호
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    • pp.195-200
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    • 1986
  • Rhizopus japonicus의 한 균주가 생산하는 효소에 의해 인삼 사포닌의 ginsenoside 중 조성비율이 가장 큰 ginsenoside $Rb_1$을 약리 효능면에서 보다 우수한 ginseuoside $Rb_1$로 선택적으로 전환할 수 있음을 TLC 및 HPLC로 정량적으로 확인하였다. Total saponin을 기질로 사용하였을 경우 ginsenoside $Rb_1$은 그 함량의 82.5%까지 ginsenoside Rd로 전환되어 ginsenoside Rd의 함량을 원래 함량에 비해 4.75배까지 증가시킬 수 있었으며, ginsenoside-Rb group saponin 기질의 경우는 80.8%의 ginsenoside $Rb_1$이 ginsenoside Rd로 전환되어 ginsenoside Rd의 함량을 34.7배까지 처리효소의 농도에 비례해서 증가시킬 수 있었다. 한편 다른 ginsenoside 함량변화 없이 오직 ginsenoside $Rb_1$에서 ginsenoside Rd만으로 선택적 전환을 한다는 사실이 당이나 sapogenin의 검출로도 증명되었다.

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Fabrication and Characterization of Dye-sensitized Solar Cells based on Anodic Titanium Oxide Nanotube Arrays Sensitized with Heteroleptic Ruthenium Dyes

  • Shen, Chien-Hung;Chang, Yu-Cheng;Wu, Po-Ting;Diau, Eric Wei-Guang
    • Rapid Communication in Photoscience
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    • 제3권1호
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    • pp.16-19
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    • 2014
  • Anodic self-organized titania nanotube (TNT) arrays have a great potential as efficient electron-transport materials for dye-sensitized solar cells (DSSC). Herewith we report the photovoltaic and kinetic investigations for a series of heteroleptic ruthenium complexes (RD16-RD18) sensitized on TNT films for DSSC applications. We found that the RD16 device had an enhanced short-circuit current density ($J_{SC}/mAcm^{-2}=15.0$) and an efficiency of power conversion (${\eta}=7.2%$) greater than that of a N719 device (${\eta}=7.1%$) due to the increasing light-harvesting and the broadened spectral features with thiophene-based ligands. However, the device made of RD17 (adding one more hexyl chain) showed smaller $J_{SC}(14.1mAcm^{-2})$ and poorer ${\eta}(6.8%)$ compare to those of RD16 due to smaller amount of dye-loading and less efficient electron injection for the RD17 device than for the RD16 device. For the RD18 dye (adding one more thiophene unit and one more hexyl chain), we found that the device showed even lower $J_{SC}(13.2mAcm^{-2}) $ that led to a poorest device performance (${\eta}=6.2%$) for the RD18 device. These results are against to those obtained from the same dyes sensitized on $TiO_2$ nanoparticle films and they can be rationalized according to the electron transport kinetics measured using the methods of charge extraction and transient photovoltage decays.

인플래터블 카약 개발을 위한 유체역학적 성능평가 (Hydrodynamic evaluation for developing the inflatable kayak)

  • 하종규;임이영;기재석
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권6호
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    • pp.623-630
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    • 2013
  • 본 연구는 기 개발된 인플래터블 카약(RPO-2)과 새롭게 개발된 인플래터블 카약(RD-FK-11, RD-FK-12)의 유체역학적인 성능평가를 위하여 경사시험과 선회시험은 해양공학수조에서 저항시험은 축소된 모형선을 제작하여 회류수조에서 수행되었다. 결론적으로 각각의 카약에 대한 다양한 성능시험결과 복원성 측면에서는 KONA가 유리하고, 선회력과 무게중심 측면에서는 RD-FK-12가 우수하고, 저항성능 측면에서는 RD-FK-11이 KONA와 RPO-2에 비해 우수하였다.

Production of Transgenic Pig Harboring Tissue-type Plasminogen Activator Gene with Bovine-$\beta$-Casein Promoter

  • Park, J.K.;Lee, Y.K.;Lee, P.Y.;Kim, S.W.;Jeon, I.S.;Lee, H.G.;Han, J.H.;Park, C.G.;Lee, S.E.;Beak, K.N.;Chang, W.K.
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.190-190
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    • 2004
  • Tissue plasminogen activator (tPA) plays important roles in the brain after excitotoxic injury. This study was conducted to produce transgenic pig harboring human tissue plasminogene activator (htPA) gene. Recombinent htPA(rhtPA) genes containing bovine-β-casein promoter (bBC) were prepared for microinjection and testified the expression level of htPA protein from the Chinese hamster ovary (CHO) cell lines before NDA microinjection into the porcine pronuclei. (omitted)

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Expression of GFP Gene in Porcine Embryos after ICSI with Different DNA Binding Methods

  • Han, J. H.;Kim, S.W.;Lee, Y.K.;Lee, P.Y.;Park, C.G.;Lee, S.E.;Baek, K.N.;Lee, H.G.;Lee, J.Y.;Chang, W.K.;Park, J.K.
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.191-191
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    • 2004
  • Transgenic animals are produced primarily by microinjecting exogenous DNA into the male pronuclei of a zygote. Microinjection method for gene transmitting is successful in mice but not efficient in farm animals, limiting it's general utility such as a large scale facility and labour. Based on our finding that sperm cells bind with exogenous DNA, sperm was used as a vector for producing transgenic animals to introduced green fluorescence protein(GFP) gene. (omitted)

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