• 제목/요약/키워드: Organic EL

검색결과 330건 처리시간 0.027초

Chemical Composition and Feeding Value of Chopped Date Fronds (CDF) as Affected by Urea and Date Syrup Extract Treatment

  • El Hag, M.G.;El Shargi, K.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권6호
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    • pp.685-691
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    • 1998
  • In the first of two experiments, chemical composition (Ash, CP and CF contents), nutritive value (in vitro organic matter disappearance "lVOMD" and energy content "ME") and nitrogen retention of chopped date fronds (CDF) as affected by chemical treatment (CT) and storage duration (SD) were investigated. The experimental design was a completely randomized block, arranged in a $3{\times}4$ factorial, with 3 (CT) and 4 (SD) as the main factors using 2 replications / treatment. Three chemical treatments, were used : Control (With zero or no chemical treatment); treatment with 4% urea solution (w /w) and treatment with 4% urea + Date syrup extract (DS). The 4 (SD) were: Control (immediately after opening - without any storage or zero time storage); one month storage period; two months storage period and three months storage period. Both (CT) and (SD) had significant effects (p < 0.05) on CP and ash contents of the CDF, however there were no significant effects (p > 0.05) due to (CT) and (SD) on CF and nutritive value. High retention value (> 80%) for nitrogen was reported for the treated CDF, immediately after opening the incubated material (zero SD). However, nitrogen retention decreased with increasing (SD) to 67% after one month (SD) but tended to stay at a fairly constant level of 67% until 3 months of storage. In experiment 2, the feeding value of treated CDF was evaluated in comparison to Rhodes grass hay, using growing goats and sheep. A $4{\times}2$ factorial design was used (Four roughage sources were used : Rhodes grass hay, untreated CDF, urea-treated CDF and CDF treated with urea + DS with sheep and goats as two animal species, using three animals / treatment). Untreated CDF had a similar feeding value to Rhodes grass hay. However treatment of CDF with urea alone or with urea + DS depressed animal performance of both goats and sheep, apparently due to depression of feed intake (appetite). Feeding untreated CDF decreased feeding cost by 29% and cost/kg gain by 23%. CDF showed a good potential as a cheap local roughage and emergency feed for ruminants in the Sultanate.

Mild stimulation of stomach 36 acupuncture point by organic nanoscale SP6 patch improves cellular physiologic functional status of different organs

  • Nazeran, Homer;Blake-Greenberg, Sherry;Haltiwanger, Emily
    • 셀메드
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    • 제2권1호
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    • pp.10.1-10.6
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    • 2012
  • Acupuncture works by stimulating peripheral sensory nerves and their endings causing an increase in cutaneous blood flow and microcirculation, as well as release of neurotransmitters, neuropeptides, and hormones. SP6 Patch is a nanoscale nontransdermal device that mildly stimulates Stomach 36 (zusanli) and other acupuncture points. As stimulation of these points has been indicated to have an effect on hypothalamic function, it is of great research interest to investigate the effect of SP6 Patch on the physiology of organs that are affected by hypothalamic regulation. Bioelectrical tissue impedance data indicative of cellular physiologic organ function, using an Electro Interstitial Scan (EIS) system, were acquired from hypothalamus, pancreas, liver, intestines, kidneys, thyroid and adrenal glands in 10 (1 male, 9 females) volunteers while wearing the SP6 Patch daily for 1 week. EIS testing was performed at baseline with no patch, 30 min after wearing the patch, and after wearing the patch 12 h/day for 1 week. Subjects were instructed to keep well hydrated during the study period. All subjects served as their own control. The hypothesis was: The SP6 Patch worn 12 h/day on the Stomach 36 acupuncture point for 1 week, may significantly improve cellular physiologic functional status of different organs measured by EIS. All tested organs achieved significant improvement in their functional physiologic status after wearing the SP6 Pach 12 h/day for 1 week compared to baseline with an overall average statistical power > 89%. Based upon these results the hypothesis was accepted as true.

Effect of condensed tannins from Leucaena leucocephala on rumen fermentation, methane production and population of rumen protozoa in heifers fed low-quality forage

  • Pineiro-Vazquez, Angel T.;Canul-Solis, Jorge R.;Jimenez-Ferrer, Guillermo O.;Alayon-Gamboa, Jose A.;Chay-Canul, Alfonso J.;Ayala-Burgos, Armin J.;Aguilar-Perez, Carlos F.;Ku-Vera, Juan C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제31권11호
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    • pp.1738-1746
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    • 2018
  • Objective: The aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers. Methods: Five crossbred heifers (Bos taurus${\times}$Bos indicus) (BW: $295{\pm}6kg$) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a $5{\times}5$ Latin square design. Results: The voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ~61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found. Conclusion: Inclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.

Influence of hydraulic retention time on biogas production during leachate treatment

  • Baati, Souaad;Benyoucef, Fatima;Makan, Abdelhadi;El Bouadili, Abdelaziz;El Ghmari, Abderrahmene
    • Environmental Engineering Research
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    • 제23권3호
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    • pp.288-293
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    • 2018
  • The main objective of this study is to investigate the influence of hydraulic retention time (HRT) on biogas production during leachate treatment using an anaerobic reactor type Upflow Anaerobic Sludge Blanket. For this purpose, four HRTs ranging from 12 to 48 h were experienced. The obtained results showed that higher amount of biogas could be produced during longer HRTs. However, HRTs longer than 48 h could not affect clearly the biogas generation and considered as unnecessary given the small additional amount of biogas produced during the degradation process. A volume of $0.434L/L_{leachate}/d$ was achieved during the treatment with a HRT of 48 h. The higher biogas production, the smaller chemical oxygen demand (COD) values achieved. Besides, COD removal and biogas production positively correlate, showing that the active biomass has degraded effectively the organic load to produce biogas. Moreover, all the analyzed physicochemical parameters have experienced a decrease after 48 h except for the pH, which increased to approximately neutral value. More precisely, a decrease of 93.8%, 89.7%, 95%, 70%, 77%, and 84.4% was recorded for COD, electrical conductivity, total suspended solid, turbidity, $NH_4{^+}-N$, and $NO_3{^-}-N$, respectively.

란탄계 금속 착화합물을 이용한 다양한 유기 전기 발광 소자의 연구 (A Study on the Various Organic Electroluminescent Devices Using Lanthanide Chelate Metal Complexes)

  • 표상우;이한성;김정수;이승희;김영관
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.529-532
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    • 1999
  • 본 연구에서는 유기 전기 발광 소자에서 녹색 발광층으로 사용되는 terbium(Tb) complexes와 europium(Eu) complex, 정공 수송층으로 사용되는 TPD (N, N\`-diphenyl-N,\`(3-methylphenyl)-1, 1\`biphenyl-4, 4\`-diamine), 그리고 전자 수송층으로 사용되는 Alq$_{3}$ (trois(8-hydroxyquinolino)aluminum), Bebq$_2$들의 Uv/Vis. 홉광도와 PL 스펙 트럼과 같은 광학적 특성을 조사하였으며 또한 이러한 물질들을 이용하여 다양한 종류의 유기 전기 발광 소자를 제작하고 제작된 소자들의 전류밀도-전압-조도 등의 전기 . 광학적 특성을 조사하였으며, 그 결과 다 음과 같은 결곤을 얻을 수 있었다. 다양한 ligand를 갖는 Tb complex들의 경우에도 EL 스펙트럼의 파장대 (wavelength)는 546nm~548nm의 녹색 발광을 하는 것을 알 수 있었고, 제작된 소자 중에서 Tb(ACAC)$_3$(Phen) 을 발광충으로 하고, TPD, 그리고 Bebq$_2$를 각각 정공 수송층, 전자 수송 층으로 한 소자가 가장 낮은 구동 전압을 갖는다는 것을 확인하였으며 logJ-logV 특성에서도 모든 전계 구간에서 이러한 구조의 소자가 가장 높은 전류밀도를 나타냈으며 저 전계 구간에서 전류밀도 타이가 가장 컸다. 소자의 전류밀도와 휘도의 관계에 있어서는 제작된 네 종류의 소자 중 Tb(ACAC)3(Cl-Phen)를 발광층으로 하고 TPD, 그리고 Bebq2를 각각 정공 수송층, 전자 수송 층으로 한 소자가 가장 휘도가 우수한 것을 알 수 있었다. 또한 red (europium complex), green (terbium complex), 그리고 blue (TPD) 색깔을 나타내는 유기 재료를 사용하여 한 소자에서 백색 소자를 제작하여 cyclic voltametric방법을 이용하여 각 유기 물질들의 에너지 준위를 조사하여, 각각의 소자들을 에너지 밴드 다이어그램(energy band diagram)으로 자세히 설명하였다.

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페릴렌과 트리아진기를 측쇄로 가지는 청색 발광 공중합체의 전기발광 특성 (Electroluminescence Characteristics of Blue Light Emitting Copolymer Containing Perylene and Triazine Moieties in the Side Chain)

  • 이창호;류승훈;오환술;오세용
    • 폴리머
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    • 제28권5호
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    • pp.367-373
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    • 2004
  • 발광체로 페릴렌기와 전자 전달체로 트리아진기를 측쇄로 가지는 새로운 비공액계 청색 발광 공중 합체를 합성하였다. 제조한 공중합체는 클로로벤젠, THF 클로로포름, 벤젠과 같은 일반 유기 용매에 매우 잘 녹았다. 전도성 투명 전극 (ITO)/공중합체 /알루미늄으로 구성된 단층형 유기 발광 소자는 공중합체에서 트리아진의 함유량이 $30\%$일 때 캐리어 균형이 잘 맞았고 최고의 외부 양자 효율 ($0.003\%$)을 나타내었다. 특히 위에서 제작한 유기 발광 소자는 페릴렌 발광체에 상응하는 청색 발광 (479 nm)을 나타냈다. 구동 전압은 5V로 매우 낮았고, 색 좌표는 X 값이 0.16, Y 값이 0.17이었다.

발광형 교통안전표지용 청색 OLED의 특성분석에 관한 연구 (A Study on the Characteristic Analysis of Blue OLED for the Luminous Traffic Safety Mark)

  • 강명구;김중연;오환술
    • 한국ITS학회 논문지
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    • 제6권2호
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    • pp.138-145
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    • 2007
  • 발광형 교통안전표지는 안개가 잦은 곳, 야간 교통사고가 많이 발생하거나 발생가능성이 높은 곳, 도로의 구조로 인하여 가시거리가 충분히 확보되지 않은 곳 등과 같은 장소에서 제한적으로 사용하도록 규정 되었다. 현재 발광형 교통안전표지는 LED가 사용되고 있으나, 향후 새로운 교통안전표지용으로 유기발광다이오드를 제안하였다. 소자의 구조는 $ITO/2-TNATA(500{\AA})/{\alpha}-NPD(200{\AA})/DPVBi(300{\AA})/BCP(10{\AA})/Alq3(200{\AA})/LiF(10{\AA})/Al:Li(1000{\AA})$로 하였다. 인가전압 10 V에서 전류밀도는 $240.71mA/cm^2$, 휘도는 $10,550cd/m^2$, 발광효율은 3.53cd/A이었다. $N_2$ 가스가 주입된 플라즈마로 전처리한 ITO 표면을 갖는 소자가 플라즈마 전처리되지 않은 ITO 표면을 갖는 소자보다 특성이 향상되었다. EL 스펙트럼의 최대 발광 파장은 456nm이었고 색좌표값은 x=0.1449, y=0.1633으로 NTSC 색좌표 Deep blue 영역(x=014, y=0.08)에 근접한 순수한 청색에 가까운 값을 얻었다.

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Synthesis and Color Tuning of Poly(p-phenylenevinylene) Containing Terphenyl Units for Light Emitting Diodes

  • Jin, Young-Eup;Kim, Jin-Woo;Park, Sung-Heum;Kim, Hee-Joo;Lee, Kwang-Hee;Suh, Hong-Suk
    • Bulletin of the Korean Chemical Society
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    • 제26권11호
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    • pp.1807-1818
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    • 2005
  • New PPV based conjugated polymers, containing terphenyl units, were prepared as the electroluminescent (EL) layer in light-emitting diodes (LEDs). The prepared polymers, poly[2,5-bis(4-(2-etylhexyloxy)phenyl)-1,4-phenylenevinylene] (BEHP-PPV), poly[2-(2-ethylhexyloxy)-5-(4-(4-(2-etylhexyloxy)phenyl)phenyl)-1,4-phenylenevinylene] (EEPP-PPV) and poly[2-(2-ethylhexyloxy)-5-(9,9-bis(2-etylhexyl)fluorenyl)-1,4 phenylenevinylene] (EHF-PPV), were soluble in common organic solvents and used as the EL layer in double layer light-emitting diodes (LEDs) (ITO/PEDOT/polymer/Al). The polymers were prepared by the Gilch reaction. The number-average molecular weight $(M_n)$, weight-average molecular weight $(M_w)$, and the polydispersities (PDI) of these polymers were in the range of 9000-58000, 27000-231000, 2.9-3.9, respectively. These polymers have quite good thermal stability with decomposition starting above 320-350. The polymers show photoluminescence (PL) with maximum peaks at around 526-562 nm (exciting wavelength, 410 nm) and blue EL with maximum peaks at around $\lambda_{max}$ = 526-552 nm. The current-voltageluminance (I-V-L) characteristics of polymers show turn-on voltages of 5 V. Even though both of EEPP-PPV and BEHP-PPV have the same terphenyl group in the repeating unit, EEPP-PPV with directly substituted alkoxy group in the back bone has longer effective conjugation length than BEHP-PPV, and exhibits red shift in the PL spectra. Both of EEPP-PPV and EHF-PPV have ter-phenyl units and directly substituted alkoxy group in back bone. EHF-PPV with fluorenyl unit attached to the PPV backbone has shorter effective conjugation length than EEPP-PPV with biphenyl unit, and exhibits blue shift in the PL spectra.

Excimer-Based White Phosphorescent OLEDs with High Efficiency

  • Yang, Xiaohui;Wang, Zixing;Madakuni, Sijesh;Li, Jian;Jabbour, Ghassan E.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1520-1521
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    • 2008
  • There are several ways to demonstrate white organic light emitting diodes (OLEDs) for displays and solid state lighting applications. Among these approaches are the stacked three primary or two complementary colors light-emitting layers, multiple-doped emissive layer, and excimer and exciplex emission [1-10]. We report on white phosphorescent excimer devices by using two light emitting materials based on platinum complexes. These devices showed a peak EQE of 15.7%, with an EQE of 14.5% (17 lm/W) at $500\;cd/m^2$, and a noticeable improvement in both the CIE coordinates (0.381, 0.401) and CRI (81). Devices with the structure ITO/PEDOT:PSS/TCTA (30 nm)/26 mCPy: 12% FPt (10 nm) /26 mCPy: 2% Pt-4 (15 nm)/BCP (40 nm)/CsF/Al [device 1], ITO/PEDOT:PSS/TCTA (30 nm)/26 mCPy: 2% Pt-4 (15 nm)/26 mCPy: 12% FPt (10 nm)/BCP (40 nm)/CsF/Al [device 2], and ITO/PEDOT:PSS/TCTA (30 nm)/26 mCPy: 2% Pt-4: 12% FPt (25 nm)/BCP (40 nm)/CsF/Al [device 3] were fabricated. In these cases, the emissive layer was either the double-layer of 26 mCPy:12% FPt and 15 nm 26 mCPy: 2% Pt-4, or the single layer of 26mCPy with simultaneous doping of Pt-4 and FPt. Device characterization indicates that the CIE coordinates/CRI of device 2 were (0.341, 0.394)/75, (0.295, 0.365)/70 at 5 V and 7 V, respectively. Significant change in EL spectra with the drive voltage was observed for device 2 indicating a shift in the carrier recombination zone, while relatively stable EL spectra was observed for device 1. This indicates a better charge trapping in Pt-4 doped layers [10]. On the other hand, device 3 having a single light-emitting layer (doped simultaneously) emitted a board spectrum combining emission from the Pt-4 monomer and FPt excimer. Moreover, excellent color stability independent of the drive voltage was observed in this case. The CIE coordinates/CRI at 4 V ($40\;cd/m^2$) and 7 V ($7100\;cd/m^2$) were (0.441, 0.421)/83 and (0.440, 0.427)/81, respectively. A balance in the EL spectra can be further obtained by lowering the doping ratio of FPt. In this regard, devices with FPt concentration of 8% (denoted as device 4) were fabricated and characterized. A shift in the CIE coordinates of device 4 from (0.441, 0.421) to (0.382, 0.401) was observed due to an increase in the emission intensity ratio of Pt-4 monomer to FPt excimer. It is worth noting that the CRI values remained above 80 for such device structure. Moreover, a noticeable stability in the EL spectra with respect to changing bias voltage was measured indicating a uniform region for exciton formation. A summary of device characteristics for all cases discussed above is shown in table 1. The forward light output in each case is approximately $500\;cd/m^2$. Other parameters listed are driving voltage (Bias), current density (J), external quantum efficiency (EQE), power efficiency (P.E.), luminous efficiency (cd/A), and CIE coordinates. To conclude, a highly efficient white phosphorescent excimer-based OLEDs made with two light-emitting platinum complexes and having a simple structure showed improved EL characteristics and color properties. The EQE of these devices at $500\;cd/m^2$ is 14.5% with a corresponding power efficiency of 17 lm/W, CIE coordinates of (0.382, 0.401), and CRI of 81.

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청색 유기발광소자 제작 및 특성분석에 관한 연구 (A Study on the Fabrication and Characteristic Analysis of Blue Organic Light Emitting Devices)

  • 김중연;노병규;강명구;오환술
    • 대한전자공학회논문지TE
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    • 제39권1호
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    • pp.9-15
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    • 2002
  • 본 논문은 청색 유기 EL 소자를 진공증착법으로 제작하여 그 특성을 분석하였다. 발광층 물질(A1q/sub 3/)에 게스트물질(Type I-TPB와 Type II-DPA)의 도핑농도(0.5∼2 wt%)를 변화시켜 청색발광소자를 제작하여 전기적, 광학적 특성을 조사하였다. Alq3에 도펀트의 농도를 증가함에 따라 청색에 해당하는 색좌표 점으로 이동하였다. Type I이 Type II의 경우보다 동작개시전압 및 구동전압이 낮게 나타났으며 휘도에서는 Type II가 밝게 나타났다. Alq/sub 3/에 DPA(2wt%)를 도펀트로 사용한 소자의 경우 인가전압 15V에서 휘도는 1282cd/m/sup 2/, 최대발광 파장은 476nm, 색좌표는(0.1273, 0.0672)으로 우수한 특성을 나타내었다.