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가변 사판식 압축기의 탑 클리어런스 측정 방법 및 신뢰성 확보에 관한 연구 (Study on the Measuring Method and Reliability of Top Clearance of Variable Swashplate Type Compressor)

  • 김영신;나승규
    • 설비공학논문집
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    • 제28권3호
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    • pp.89-94
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    • 2016
  • In this experimental study, the effects of top clearance on the performance of automotive a/c compressor were studied. Top clearance measuring device was also developed to ensure the reliability using vacuum conditions to secure constant control of top clearance without external environmental influence. Our results revealed that the improvements in compressor performance according to different top clearance values using the same compressor and same operator were about 4.12% at 800 rpm and about 7.8% at 2,000 rpm in 0.243~0.252 mm of top clearance compared to 0.431~0.456 mm of top clearance. To confirm the consistency in measuring top clearance affecting compressor performance, the top clearance measuring device was developed in this study using a vacuum pump. After performing reliable tests repeatedly, the distribution of measuring values under this device was within 0.99~1.83%, indicating that the constant test data in compressor performance was not affected by any other external environment.

Photocatalytic Systems of Pt Nanoparticles and Molecular Co Complexes for NADH Regeneration and Enzyme-coupled CO2 Conversion

  • Kim, Ellen;Jeon, Minkyung;Kim, Soojin;Yadav, Paras Nath;Jeong, Kwang-Duk;Kim, Jinheung
    • Rapid Communication in Photoscience
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    • 제2권2호
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    • pp.42-45
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    • 2013
  • Natural photosynthesis utilizes solar energy to convert carbon dioxide and water to energy-rich carbohydrates. Substantial use of sunlight to meet world energy demands requires energy storage in useful fuels via chemical bonds because sunlight is intermittent. Artificial photosynthesis research focuses the fundamental natural process to design solar energy conversion systems. Nicotinamide adenine dinucleotide ($NAD^+$) and $NADP^+$ are ubiquitous as electron transporters in biological systems. Enzymatic, chemical, and electrochemical methods have been reported for NADH regeneration. As photochemical systems, visible light-driven catalytic activity of NADH regeneration was carried out using platinum nanoparticles, molecular rhodium and cobalt complexes in the presence of triethanolamine as a sacrificial electron donor. Pt nanoparticles showed photochemical NADH regeneration activity without additional visible light collector molecules, demonstrating that both photoactivating and catalytic activities exist together in Pt nanoparticles. The NADH regeneration of the Pt nanoparticle system was not interfered with the reduction of $O_2$. Molecular cobalt complexes containing dimethylglyoxime ligands also transfer their hydrides to $NAD^+$ with photoactivation of eosin Y in the presence of TEOA. In this photocatalytic reaction, the $NAD^+$ reduction process competed with a proton reduction.

Investigation of transport of radionuclide in a thermal stratification test facility using radiotracer technique

  • Pant, Harish Jagat;Goswami, Sunil;Chafle, Sunil B.;Sharma, Vijay Kumar;Kotak, Vimal;Shukla, Vikram;Mishra, Amitanshu;Gohel, Nilesh C.;Bhattacharya, Sujay
    • Nuclear Engineering and Technology
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    • 제54권4호
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    • pp.1449-1455
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    • 2022
  • A radiotracer investigation was carried out in a Thermal Stratification Test Facility (TSTF) with objectives of investigating the dispersion and diffusion of radionuclide and effectiveness of the thermocline to minimize the radionuclide content in the hot water layer. Technetium-99m (99mTc) as sodium pertechnetate was used as a radiotracer in the investigation. Qualitative analysis showed that a thermocline is formed within the TSTF and is effective in preventing the transport of radionuclide from bottom section to the top section of the facility. It was found that the radiotracer injected at the bottom of the pool took about 17.4 h to disperse from bottom to the top of the facility. The results of the investigation helped in understanding the effectiveness of hot water layer and thus to minimize the pool top radiation levels.

Microcavity Effect of Top-emission Organic Light-emitting Diodes Using Aluminum Cathode and Anode

  • Lee, Chang-Jun;Park, Young-Il;Kwon, Jang-Hyuk;Park, Jong-Wook
    • Bulletin of the Korean Chemical Society
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    • 제26권9호
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    • pp.1344-1346
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    • 2005
  • We report microcavity effect of top emission organic light-emitting diodes (OLEDs) by using Al cathode and anode, which are feasible for not only top emission EL and angle dependant effects but facile evaporation process without ion sputtering. The device in case of $Alq_3$ green emission showed largely shifted EL maximum wavelength as 650 nm maximum emission. It was also observed that detection angle causes different EL maximum wavelength and different CIE values in R, G, B color emission. As a result, the green device using $Alq_3$ emission showed 650 nm emission ($0^{\circ}$) to 576 nm emission ($90^{\circ}$) as detection angle changed. We believe that these phenomena can be also explained with microcavity effect which depends on the different length of light path caused by detection angle.

동력 철도차량 기관실의 효과적인 환기에 관한 실험적 연구 (Experiments on the Effective Engine Room Ventilation in a Power Car)

  • 한석윤;이진호
    • 설비공학논문집
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    • 제2권3호
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    • pp.166-176
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    • 1990
  • Experimental study was made to find the effective ways for cooling of engine room in a power car through natural ventilation, forced ventilation and wind tunnel test of 1:10 model. Through the measurements of inner temperature of engine room and pressure distribution of model surface for the various opening combinations and the fan locations, the following results are obtained. For natural ventilation, side and top opening combination is more effective than the side openings only and optimal opening combination is all side openings with top center opening. For forced ventilation with fan on the roof, the combination of all sides and top opening is more effective than the combination of side and top opening, and the optimal location of fan is top center. When the model is located in the air stream, the combination of side and top opening is more effective than the side openings only, and the optimal location of top opening is the front opening. With both air stream and forced ventilation, the optimal location of fan is the side region, and the direction of side grill installation is found to have negligible effect on the room ventilation.

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Studies on the Physiological Characteristics of (Cervus e. canadensis) Velvet Antler in Elk

  • Jeon, Byong-Tae;Thomas, David G.;Cheong, Sun-Hee;Kim, Myeong-Hwa;Kim, Sung-Jin;Sung, Si-Heung;Park, Pyo-Jam;Park, Jae-Hyun;Moon, Sang-Ho
    • Journal of Animal Science and Technology
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    • 제52권3호
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    • pp.237-244
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    • 2010
  • In order to investigate the physiological properties of velvet antler of elk (Cervus e. canadensis) raised in Korea, antlers (n=378) were collected from deer in 8 provinces including Gyeonggi-do (n=53), Gangwon-do (n=49), Chungcheongbuk-do (n=62), Chungcheongnam-do (n=68), Jeollabuk-do (n=52), Jeollanam-do (n=15), Gyeongsangbuk-do (n=30) and Gyeongsangnam-do (n=49). The exterior characteristics (weight, length, girth and crown) of all antlers were measured, and 18 antler samples were randomly selected for measurement of interior characteristics such as specific gravity, capacity and diameter of cross section. The mean antler weight, length of the main beam and mean length of upper section were $4.87{\pm}1.79\;kg$, $83.7{\pm}13.2\;cm$ and $40.6{\pm}11.4\;cm$, respectively. Mean girth of the top, middle and base of the main beam were $27.1{\pm}5.9\;cm$, $22.1{\pm}3.6\;cm$ and $22.9{\pm}3.6\;cm$ respectively, indicating a slight narrowing in the middle of the antler. In each of the tines, the girth at the base was markedly thicker compared to the top. The depth of the crown at the top of the antler, and the average number of crowns and tines were $14.1{\pm}7.0\;cm$, $2.1{\pm}0.6$ and $3.0{\pm}0.5$, respectively. Although there was no significant difference in mean specific gravity between top and base, mean specific gravity of main beam tended to increase from top to base of the antler with decreasing capacity. Additionally, the inner diameter of the base of the antler was significantly reduced compared to that of the top, indicating a greater integumental thickening due to mineralization. Information on the morphological and physiological properties of elk antlers is scarce. Therefore, these results may be useful in providing basic information for the physiological properties of antler, and encourage further studies on antler morphology in other deer species showing species specific differences.

Estimating the Economic Burden of Premature Mortality Caused by Cancer in Iran: 2006-2010

  • Karami-Matin, Behzad;Najafi, Farid;Rezaei, Satar;Khosravi, Ardashir;Soofi, Moslem
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.2131-2136
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    • 2016
  • Background: Cancer is currently one of the main public health problems all over the world and its economic burden is substantial both for health systems and for society as a whole. To inform priorities for cancer control, we here estimated years of potential life lost (YPLL) and productivity losses due to cancer-related premature mortality in Iran from 2006 to 2010. Materials and Methods: The number of cancer deaths by sex and age groups for top ten leading cancers in Iran were obtained from the Ministry of Health and Medical Education. To estimate the YPLL and the cost of productivity loss due to cancer-related premature mortality, the life expectancy method and the human capital approach were used, respectively. Results: There were 138,228 cancer-related deaths in Iran (without Tehran province) of which 76 % (106,954) were attributable to the top 10 ranked cancers. Some 63 % of total cancer-related deaths were of males. The top 10 ranked cancers resulted in 106,766,942 YPLL in total, 64,171,529 (60 %) in males and 42,595,412 (40%) in females. The estimated YPPLL due to top 10 ranked cancers was 58,581,737 during the period studied of which 32,214,524 (54%) was accounted for in males. The total cost of lost productivity caused by premature deaths because of top 10 cancers was 1.68 billion dollars (US$) from 2006 to 2010, ranging from 251 million dollars in 2006 to 283 million dollars in 2010. Conclusions: This study showed that the economic burden of premature mortality attributable to cancer is significant for Iranian society. The findings provide useful information about the economic impact of cancer for health system policy/decision makers and should facilitate planning of preventive intervention and effective resource allocation.

Effect of Antler Development Stage on the Chemical Composition of Velvet Antler in Elk (Cervus elaphus canadensis)

  • Jeon, Byong-Tae;Cheong, Sun-Hee;Kim, Dong-Hyun;Park, Jae-Hyun;Park, Pyo-Jam;Sung, Si-Heung;Thomas, David G.;Kim, Kyoung-Hoon;Moon, Sang-Ho
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권9호
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    • pp.1303-1313
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    • 2011
  • This study was conducted to provide the basic information to allow improved scientific assessment of velvet antler's quality by investigating the change of chemical composition during different antler growth stages in elk (Cervus elaphus canadensis). Twenty four antlers were harvested from elk stags (aged 4-5 years) on 65 days (VA65), 80 days (VA80) and 95 days (VA95) after button casting, and the chemical composition of each antler was determined in five sections (top, upper, middle, base, and bottom). Crude protein and ether extract content was the highest in the top section, whereas ash content was the highest in the bottom section in all groups (p<0.05). Glycosaminoglycan (GAG) content was higher in the VA65 group than in the VA95 group in the upper section of antler (p<0.05). The collagen content was higher in the VA65 group compared to the VA95 group in the middle and bottom sections (p<0.05), and increased downward from the top to the bottom section. The proportions of certain amino acids, including aspartic acid, glutamic acid and isoleucine were higher (p<0.05), whereas proline and glycine were lower in the top section of antler compared to all other sections (p<0.05). The proportion of linoleic acid, 11,14,17-eicosatrienoic acid, total ${\omega}$-3 and ${\omega}$-6 fatty acids and polyunsaturated fatty acids (PUFAs) for all sections in the VA65 group was higher than in the VA95 group (p<0.05). These results suggested that the quality of velvet antler is strongly influenced by antler development stage.

Effects of dielectric capping layer in the phosphorescent top emitting organic light emitting diodes

  • Kim, Sei-Yong;Leem, Dong-Seok;Lee, Jae-Hyun;Kim, Jang-Joo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.499-502
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    • 2008
  • Effects of a dielectric capping layer on the luminous characteristics of top emitting organic light emitting diodes (TOLEDs) have been analyzed using a classical electromagnetic theory. Special attention was given to the influence of the cavity length on the effectiveness of the capping layer. The luminance characteristics of the TOLEDs influenced by the combined effects of the cavity length and the capping layer thickness. Furthermore, these combined effects also modify the emission spectrum and pattern of the TOLEDs, which result in the improvement of total luminance of the device, but no significant change in the device out-coupling efficiency.

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