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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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    • 2008.10a
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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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Studies on the Zanthoxylum piperitum $D_E$ $C_{ANDOLIE}$ - 1. Pungent principles and Essential oil composition - (천초(川椒)에 관(關)한 연구(硏究) - 1. 신미성분(辛味成分)과 정유성분(精油成分) -)

  • Jung, Hyun-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.16 no.2
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    • pp.123-127
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    • 1987
  • The Pungent principles and Essential oil compositions of Zanthoxylum piperitum $D_E$ $C_{ANDOLIE}$(peel, barb) were analysed by HPLC and GC, respectively. Total Pungent principle contents of peels were about as 12 times as those of barks. The Sanshool I, Sanshool IV, Sanshool III and Sanshoo V were the major Pungent principles in the peels and barks. Besides, several Unknown Pungent principles were discovered in the peels and barks, too. Total Essential oil contents of peels were higher than those of barks at the ratio of 1.8 % to 0.5%. The Cineol+Limonene(37.7%) were the main Essential oil compositions in the peels, while ${\alpha}-Terpineol(16.5%)$ and Pinene(15.5%) were the major portion in the barks. The Essential oil of peels and barks were composed Pinen, Myrcene, Cineol+Limonene, Linalool, Isopulegol, Terpinen-4-ol, ${\alpha}-Terpineol$ and Piperitone. Besides, seven Unknown compositions were discovered, too.

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The Effect of 3-(4-hydroxyl -33,53-dimethoxyphenyl)propionic Acid in Chinese Cabbage Kimchi on Lowering Hypercholesterolemia (배추김치의 활성성분인 3-(4-hydroxyl-33,53-dimethoxyphenyl)propionic acid의 고지혈증 치료 효과)

  • 김현주;권명자;서정민;김재곤;송수희;서홍석;송영옥
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.52-58
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    • 2004
  • The active principle responsible for lipid lowering in Chinese cabbage kimchi, 3-(4-hydroxyl-3'5'-dimethoxyphenyl)propionic acid, of molecular weight 226, was chemically synthesized and then used for the treatment of hypercholesterolemia in male New Zealand white rabbit. Hypercholesterolemia in rabbits were induced by feeding 0.5% cholesterol added chow diet for 5 weeks. Each experimental group has four rabbits in it. for the 1st experiment,3-(4-hydroxyl-3'5'-dimethoxyphenyl)propionic acid or simvastatin was injected to the ear vein of rabbit every other day for 16 days (2 mg/3 kg/2 days) while normal chow diet was provided. Blood was drawn every 4th day. For the 2nd experiment, all the experimental condition was same as the 1st trial except 0.5% cholesterol diet was provided while 16 days. Plasma cholesterol level was decreased when cholesterol in the diet was removed. Decreased in cholesterol in kimchi and simvastatin groups were 18.65 and 29.67%, respectively compared to the control when the normal diet was given, and cholesterol increase was inhibited by 33.79 and 21.81% for kimchi and simvastatin groups, respectively, when 0.5% cholesterol diet was provided. The drop in LDL-C level by the active principle of kimchi and simvastatin was not significant when normal diet was given, however the changes was significant (p<0.05), approximately 130% decrease, when 0.5% cholesterol diet was given. The 105% and 62% decreased in triglyceride concentration were observed from 0.5% cholesterol diet fed kimchi and simvastatin groups respectively HDL cholesterol levels in experimental groups were not changed significantly from the both trials. The HMG-CoA reductase activity of kimchi and simvastatin groups were found to be higher than that of control to compensate the hypercholesterolemic condition induced by 0.5% cholesterol diet in these groups. In conclusion, diet is an important factor to control the hypercholesterolemia besides drug treatment. 3-(4-hydroxyl-3'5'-dimethoxyphenyl)propionic acid that is the active principle in Chinese cabbage kimchi seems a beneficial to the hypercholesterolemia and its effect is comparable to that of simvastatin.

A Verification on the Effectiveness of Middle Managers' Emotional Leadership in Food Service Management Companies (위탁급식업체 중간관리자의 감성리더십 효과성 검증)

  • Kim, Hyun-Ah;Jung, Hyun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.4
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    • pp.488-498
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    • 2007
  • The purposes of this study were to: a) provide evidences concerning the effects of emotional leadership b) examine the impacts of emotional leadership on employee-related variables, 'job satisfaction', 'organizational commitment', 'organizational performance' and 'turnover intention', and c) identify a conceptual framework underlying emotional leadership. A survey was conducted from August 23 to November 3, 2005 to collect data from mid-level managers in food service company headquarters (N=219). Statistical analyses were completed using SPSS Win (12.0) for descriptive, reliability, factor and correlation analyses and AMOS (5.0) for confirmatory factor analysis and structural equation modeling. The main results of this study were as follows. First, the managers gave the highest point to their leaders in the emotional leadership competence 'organizational awareness : reading the currents, decision networks, and politics at the organizational level' and gave the lowest point in the emotional leadership competence 'influence: wielding effective tactics for persuasion'. Second, the means of job satisfaction was above the midpoint (3 points). Employees' job satisfaction with 'coworkers' was relatively high. However, the extents of satisfaction with 'payroll' 'promotion', and 'work environment' were relatively low. Third, the organizational commitment was above the midpoint (3 points). In the organizational commitment, 'loyalty' factor was higher than 'commitment' factor. Fourth, the means of organizational performance was above the midpoint. The highest organizational performance variable was 'internal efficiency; trying to reduce cost' and the lowest organizational performance variable was 'internal fairness ; equitable treatment and all are treated with respect with no regard to status and grade'. Fifth, most respondents intended on 'thinking of quitting ; towards turnover process'. Sixth, the test of hypothesis using structural equation modeling found that emotional leadership produced p[Isitive effects on job attitude and job performance. Emotional leadership enhanced job satisfaction and organizational commitment, and in turn, employees' attitude positive effects on organizational performance; emotional leadership also had a direct impact on organizational performance

Effects of Long-Term Administration of Saengshik on Growth Increment, BMD and Blood IGF-1 Concentration in Growing Rats (장기간의 생식 섭취가 성장기 흰쥐의 성장, 골밀도 및 혈중 IGF-1의 농도에 미치는 영향)

  • Kim, Joong-Hark;Hong, Sung-Gil;Kim, Wha-Young;Jung, Ji-Sang;Hwang, Sung-Ju;Mok, Chul-Kyoon;Park, Mi-Hyoun;Lee, Ju-Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.4
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    • pp.439-446
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    • 2007
  • This study was performed to investigate the effect of long-term administration of Saengshik on growth parameters of growing rats. Male Sprague-Dawley rats were fed on AIN-93G basal diets for 12 weeks and assigned to the following groups: rats administrated orally with Saengshik at the dose of 1g/kg/day (1xJS ), 2g/kg/day (2xJS), 4g/kg/day (4xJS) and distilled water (Control). Rats were sacrificed at 4, 8, 12 weeks after oral administration. Bone mineral density (BMD) and bone mineral contents (BMC) were measured by PIXImus densitometry and serum insulin-like growth factor-1 (IGF-1) concentration were determined by using EIA method. Body weight and food intake did not show significant changes within groups for 12 weeks. Physical longitudinal growth indexes, body length and femur length were significantly increased in Saengshik-administered groups at 12 weeks, in which BMD and BMC also significantly increased. Also, in blood IGF-1 level, Saengshik-administered groups were remarkedly higher than control group at 4 week (p<0.001), in which significantly higher at 8 week and 12 week. These results suggest a close relation between administration of Saengshik and increment of longitudingal bone growth. Therefore, as the result of this study, it could be expected that the administration of Saengshik for 12 weeks is helpful to the increase of longitudinal growth and growth factors in rats. Furthermore, we propose that the consumption of Saengshik as dietary supplementation may promote to increase in longitudinal bone growth in growing children.

Trends in Genetic Parameters with Age and Site for Early Implications of Genetic Improvement in Korean White Pine (잣나무의 유전적(遺傳的) 형질(形質) 개량(改良)의 조기검정(早期檢定)을 위한 수령(樹齡) 및 입지별(立地別) 생장(生長)과 유전모수(遺傳母數)의 특성(特性)에 관(關)한 연구(硏究))

  • Kim, Dae Eun;Chon, Sang Keun
    • Journal of Korean Society of Forest Science
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    • v.79 no.1
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    • pp.56-70
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    • 1990
  • Eighteen Korean white pine (P. koraiensis S. et Z.) families were tested in 3 different regions from age 5 to 9. Family and site were significant sources of variation for seedling survival and field growth, whereas the effects of family x site interaction ware relatively small as compared with the former sources of variation. Variance components estimated from the separate and combined sites indicated that the most variabilities were associated with individual trees within plot. Family ${\times}$ site interaction components as a percentage of family variance decreased sharply with age. Heritability estimates varied with testing site and tree age. Combined analyses, however, showed a moderate change in heritability with increasing tree ages, and demonstrated high and stable trends of estimates, particularly in family heritabilities of tree height ($h_F{^2}=0.789-0.798$). The gains estimated from combined analysis have expected maximum or near-maximum efficiencies at age 6 or 7. Given equal intensity of selection, mass selection showed the most efficient gains within and across the sites. However, for the differences between mass and combined selections are small, selection made on the combination of family and within-family would be more effective in improving genetic gains. Indirect selection method indicated that 5-and 6-years height were all good predictors of 9-year-old height with little loss of relative efficiency (less than 10%) as compared with direct family selection at age 9. Phenotypic and genetic correlations computed on the basis of family mean values of height and diameter have shown predominantly high, positive, and statistically significant (1% level) relationships between all tested pairs of traits, which indicates that family growth maintained statistically consistent trends with age. The best families are those that maintained a stable superiority overall sites and ages in growth performance, therefore, it can be suggested that early identification of superior families at age 9 is feasible at age 5 or 6 in Pinus koraiensis S. et Z.

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Studies on the Nutritional Value of Elderberry (Sam bucus canadensis) Fruits (Elderberry(Sam bucus canadensis) 과실(果實)의 영양가(營養價)에 대(對)하여)

  • Park, Kyo Soo
    • Journal of Korean Society of Forest Science
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    • v.67 no.1
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    • pp.42-49
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    • 1984
  • The elderberry was known to the ancients for its medicinal properties, and in Europe the inner back was formerly administered as a cathartic. The flowers contain a voletile oil, and serve for the distilation of elder-lower water, used in confectionery, perfumes and lotions. The leaves are employed to impart a green colour to fat and oil, and the leaves and bark emit a sickly odour, believed to be repugnant to insect. With its unique flavor and natural food colour, commercial processing companies used the fruit mainly in the making for jam, jelly, pies, juice, and wines. Its vitamin-C content is reported by Andross (1941) as 25-30mg/100g. Harvesting and processing have been mechanized to some extent. However, the cotains with nutritional value has not been reported yet. In the present study the various contains with nutritional value in the fresh elderberry juice is reported by the quantitative analysis. In this study results obtained can be summarized as follows. 1) The fresh elderberry juice contained following mineral elements; calcium 0.012%, magnesium 0.023%, potassium 0.10%, sodium 0.0019%, iron 0.0009%, cobalt 0.0002%, zinc 0.0004%, copper 0.0001%, phosphorus 0.036%, manganese 0.0006%, iodide $1{\mu}g/g$. 2) Five kinds of vitamines were also found ; vitamin-$B_1$ $0.1{\mu}g/g$, vitamin-$B_2$ $0.5{\mu}g/g$, vitamin-C 0.3mg/g, niacin $14{\mu}g/g$, choline chloride 0.3mg/g. 3) Fresh elderberry juice also contains crude protein 1.10%, fat 0.26%, carbohydrate 6.9%, pectin 0.76%, tannin 0.89%, ash 0.80%, water 90.9% and 34.3 cal/100g. 4) The absorption spectrum of the purplishblack color of fresh elderberry juice has a peak between 523-530mm.

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Variations in Peroxidase and Nitrate Reductase Activities and Growth Populus alba × Populus glandulosa F1 Clones (제1대(第一代) 잡종(雜種)포플러, Populus alba × Populus glandulosa F1 클론의 과산화효소(過酸化酵素), 질산환원효소(窒酸還元酵素)의 활성변이(活性變異) 및 생장(生長)에 관(關)한 연구(硏究))

  • Lee, Don Koo;Kim, Gab Tae;Lee, Kyung Joon
    • Journal of Korean Society of Forest Science
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    • v.70 no.1
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    • pp.63-71
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    • 1985
  • To sled the superior clones of Populus alba ${\times}$ Populus glandulosa $F_1$, growth and some growth-related enzyme activities were examined for thirteen, two-year-old and fifteen, three-year-old trees at Seoul National University nursery in Suwon. Clonal differences in total dry weight per tree and leaf surface area per tree were significant at the 5% level. Significant correlations were found between total dry weight per tree and leaf surface area per tree (r=0.875), between leaf peroxidase activity per tree and total dry weight per tree (r=0.854), and between leaf nitrate reductase activity per tree arid total dry weight per tree (r=0.914). Leaf peroxidase and nitrate reductase activities per unit fresh weight of one-year-old tree increased with increasing leaf order numbers basipetally, reaching maximum values in the eighteenth and thirty-third leaves, respectively, and decreased gradually from those leaves to basipetal lower leaves. Clones 65-29-19, 66-15-3, 65-22-11, 66-14-93, and 66-26-55 among two-year-old trees, and clones 64-6-44, 66-14-29, 66-26-55, 65-22-11, and 68-1-54 among three-year-old trees showed greater leaf surface areas, peroxidase and nitrate reductase activities per unit leaf fresh weight than other clones, Growth of Populus alba ${\times}$ Populus glandulosa $F_1$ clones might be estimated from either leaf surface area per tree or peroxidase and nitrate reductase activities per tree. Therefore, measurements of leaf surface area and leaf enzyme activities appear useful to select superior Populus clones at early growth stages.

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The Effect of Forest Production on National Income (임업생산(林業生産)이 국민소득(國民所得)에 미치는 영향(影響))

  • Lee, Sung Yoon
    • Journal of Korean Society of Forest Science
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    • v.9 no.1
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    • pp.61-74
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    • 1969
  • Forest area in Korea ocupies as much as 68 percent of the total land area, but forest production figure in the statistics is rather trifling: that is about 2 percent of Gross National Production (G.N.P.), on the average. In view of the primary industrial sector, its production only weighs no more than 5 percent of this whole sector. Forest production written above refers only to direct forest income of the whole forest income. For the primary forest products they are in many cases used as raw materials for other interrelated industries. The added value there-from, which arises from round about production Process, in other word, indirect income is of most singnificance. Nevertheless, until nowadays forest production has been merely refered to timber production i, e, direct production but indirect income has never been looked upon. In this regard, calculated indirect forest income by means of input ratio method. The material used were Leontiefls tables of two 1963 and 1966 fiscal years, surveyed and analysed by The Bank of Korea. Indirect forest income calculated were 42,688,200,000 won in 1963 and 74,789,800,000 won in 1966 compared direct forest income of 14,361,000,000 won in 1963 and 17,709,000,000 won in 1966. So far as indirect forest income is considered total forest production indices composed of direct and indirect forest income amount to 8.23% in 1963 and 10.12% in 1966 of Gross National Production. Invisuable forest income which originates from, what we cal, indirect benefit of forestry such as land conservation, flood and drought control, soil run off control, scenic beauty and many others is naturall, not included in the calculation. As already mentioned, primary forest products are, for the most part, utilized as raw materials for other industries, therefore indirect forest income is rather appreciable than direct forest income, contributing for the growth and development of other connected industries. In these points of view, forestry must not be evaluated trifling in deciding industrial importances.

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Quality Characteristics of Factory-Style and Handmade-Style Ssamjang (공장 및 수공업 생산 쌈장의 품질 특성)

  • Kim, Seok Young;Park, Bo Ram;Yoo, Seon Mi
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.1
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    • pp.100-108
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    • 2016
  • This study investigated the quality characteristics of factory-style ssamjang (FSS) and commercial handmade-style ssamjang (HSS) products. Moisture, crude protein, and crude fat contents were significantly higher in the HSS groups (49.37~62.12%, 9.39~13.46%, and 4.40~8.35%) than the FSS groups (41.94~45.83%, 7.50~9.09%, and 1.81~3.36%). Salt content was higher in the HSS groups (6.33~11.18%) than the FSS groups (6.10~7.57%). Moreover, the average salt content (7.51%) of the HSS groups and the FSS groups was lower than that of commercial ssamjang (8.73%). Hunter's color value was also significantly higher in the FSS groups. However, free sugar, organic acid, and free amino acids contents varied greatly between the FSS groups and the HSS groups, which was likely due to the different manufacturing method, ripening degree of doenjang and the main material used for ssamjang.