• 제목/요약/키워드: Primary Air

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FMEA of Electrostatic Precipitator for Preventive Maintenance (전기집진기 예지보전 단계에서의 고장모드영향분석)

  • Han, Seung-Hun;Lee, Jeong-Uk;Lee, Sun-Youp;Hwang, Jong-Deok;Kang, Dae-Kon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.6
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    • pp.706-714
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    • 2020
  • Currently, 90 % of the world's population breathes air with a fine dust content exceeding the World Health Organization's annual average exposure limit (10 ㎍/㎥). Global efforts have been devoted toward reducing secondary pollutants and ultra-fine dust through regulations on nitrogen oxides released over land and sea. Domestic efforts have also aimed at creating clean marine environments by reducing sulfur emissions, which are the primary cause of dust accumulation in ships, through developing and distributing environment-friendly ships. Among the technologies for reducing harmful emissions from diesel engines, electrostatic precipitator offer several advantages such as a low pressure loss, high dust collection efficiency, and NOx removal and maintenance. This study aims to increase the durability of a ship by improving equipment quality through failure mode effects analysis for the preventive maintenance of an electrostatic precipitator that was developed for reducing fine dust particles emitted from the 2,427 kW marine diesel engines in ships with a gross tonnage of 999 tons. With regard to risk priority, failure mode 241 (poor dust capture efficiency) was the highest, with an RPN of 180. It was necessary to determine the high-risk failure mode in the collecting electrode and manage it intensively. This was caused by clearance defects, owing to vibrations and consequent pin loosening. Given that pin loosening is mainly caused by vibrations generated in the hull or equipment, it is necessary to manage the position of pin loosening.

Conservational Treatment and Deterioration Assessment of the Sculptured Standing Buddha Named Taehwa 4 Year in the Jincheon, Korea (진천태화4년명 마애불의 풍화훼손도 평가와 보존처리)

  • Lee, Chan Hee;Kim, Sun Duk;Han, Byeong Il;Kim, Yeong Taek;Lee, Myeong Seong
    • Journal of Conservation Science
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    • v.16 s.16
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    • pp.39-51
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    • 2004
  • The standing Buddha named Taehwa 4 yew in the Jincheon were sculptured with rock cliff of the dark grey shale. Front of the Buddha statue shows $N40^{\circ}W$ strike with nearly vertical dip toward the back side. Rock blocks of the Buddha statue well developed with bedding and laminations whereas rock surface distributed into the various irregular discontinuities. Sculptured lines of the Buddha were uncertain because of degradation and exfoliations on the rock surface. The surface near the Buddha statue is highly contaminated with lichen and mosses, and accelerate physical and biological weathering owing to the roots of weed and bush along the fracture systems. For the conservational treatment, we treated with primary wet cleaning by air gun and secondary cleaning treatment using distilled water. Separated rock surface and fractured parts fasten and/or fill up the boundaries of the rock blocks using epoxy resin for conservation of rock properties. Some brittle surface was treatment with water repellent consolidant of ethyl silicates, and heterogeneous surface carried out color matching by acrylic pigments. Upper part of the Buddha statue dig out small ditch for rain water drainage, and near surface of the Buddha statue treat removal works for lichen, weeds and bush. The duration capacity of the Buddha constituting rocks are degraded by various weathering factors, therefore we suggest that this Buddha statue have need to do long term monitoring and synthetic conservation researches.

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High Time-resolution Characterization of PM2.5 Sulfate Measured in a Japanese Urban Site

  • Ma, Chang-Jin;Kang, Gong-Unn;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • v.9 no.4
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    • pp.280-287
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    • 2015
  • The high time-resolution monitoring data are essential to estimate rapid changes in chemical compositions, concentrations, formation mechanisms, and likely sources of atmospheric particulate matter (PM). In this study, $PM_{2.5}$ sulfate, $PM_{2.5}$, $PM_{10}$, and the number concentration of size-resolved PMs were monitored in Fukuoka, Japan by good time-resolved methods during the springtime. The highest monthly average $PM_{2.5}$ sulfate was found in May ($8.85{\mu}g\;m^{-3}$), followed by April ($8.36{\mu}g\;m^{-3}$), March ($8.13{\mu}g\;m^{-3}$), and June ($7.22{\mu}g\;m^{-3}$). The cases exceed the Japanese central government's safety standard for $PM_{2.5}$ ($35{\mu}g\;m^{-3}$) reached 10.11% during four months campaign. The fraction of $PM_{2.5}$ sulfate to $PM_{2.5}$ varied from 12.05% to 68.11% with average value of 35.49% throughout the entire period of monitoring. This high proportion of sulfate in $PM_{2.5}$ is an obvious characteristic of the ambient $PM_{2.5}$ in Fukuoka during the springtime. However, the average fraction of $PM_{2.5}$ sulfate to $PM_{2.5}$ in three rain events occurred during our intensive campaign fell right down to 15.53%. Unusually high $PM_{2.5}$ sulfate (> $30{\mu}g\;m^{-3}$) marked on three days were probably affected by the air parcels coming from the Chinese continent, the natural sulfur in the remote marine atmosphere, and a large number of ships sailing on the nearby sea. The theoretical number concentration of $(NH_4)_2SO_4$ in $PM_{0.5-0.3}$ was originally calculated and then compared to $PM_{2.5}$ sulfate. A close resemblance between the diurnal variations of the theoretically calculated number concentration of $(NH_4)_2SO_4$ in $PM_{0.5-0.3}$ and $PM_{2.5}$ sulfate concentration indicates that the secondary formed $(NH_4)_2SO_4$ was the primary form of sulfate in $PM_{2.5}$ during our monitoring period.

Composition, Source, and Regional Concentration of PBDEs in Pine Needles (소나무 잎 중 PBDEs의 조성, 발생원 및 지역적 농도)

  • Yeo, Hyun-Gu;Cho, Ki-Chul;Chun, Man-Young
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.8
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    • pp.829-835
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    • 2006
  • The composition, source, and regional concentration of polybrominated diphenyl ethers(PBDEs) were measured in pine needles with several sites in Korea. Homologs specific analysis confirmed that hepta-BDE(bromodiphenyl ethers) through deca-BDE were predictive indicator for total PBDEs concentration(Pearson's correlation coefficient r>0.96, p<0.001). Deca-BDE were detected in relatively very high concentration compared to other PBDE congeners in all samples. The similarity of between congeners profile to those of Bromkal 70-5DE and DE-71, the commercial mixture of PBDEs, indicates these mixtures are source of PBDEs observed in these sites. Also, BDE-47, -99, -100, -206, -207, and -209 were the dominant congeners in all samples, suggesting that the widely used commercial penta- and deca-BDE technical mixture were the original sources. However, Pearson's correlation coefficients of between BDE-209 and BDE-47, -99, -100 were insignificant, which implied that tetra-BDE and penta-BDE may originate from secondary sources such as air-plant partition in manner similar to that of the PCBs, while deca-BDE formulation still has primary sources.

A Study on the Cold and Heat Syndromes in Dongyi-Soose-Bowon (『동의수세보원(東醫壽世保元』에 나타난 한열증(寒熱證)에 대한 고찰(考察))

  • Lee, Kyung-ro;Kim, Kyung-yoo
    • Journal of Sasang Constitutional Medicine
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    • v.11 no.1
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    • pp.79-102
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    • 1999
  • 1. Purpose : This studied Cold and Heat syndromes about Four-form Constitutional Physicalogy. It is for help the comprehension, diagnosis and treatment of physicalogy and pathology about each type. 2. Method : I studied the conception of Cold and Heat sydrome in the existing Oriental Medicine before Constitutinal Medicine, through a few symptoms(constipation, diarrhea, sweat, urine, vomiting) and physicalogy, pathology in Dongyi-Soose-Bowon. 3. Results & Conclusion : In the viewpoint of Pathological Disease and a Chapter Name, Shaoyin has the Exterior-Febrile and Interior-Cold Disease, as the constitutional primary cause of the Interior-Cold Disease, Shaoyang has the Exterior-Cold and Interior-Febrile Disease, as the Interior-Febrile Disease, accoreing to the process of the promote incomings and outgoings of food stuffs of the Spleen and Kidney. By the way, Taiyin is classified into 'One who had had the Cold Disease Primarily and the Febrile', Taiyang has the nature of 'No Cold, No Heat' that is not tendency to The Cold or Heat sydromes, according to promote the respiration of air and fluid of the Liver and Lung. In the viewpoint of a few symptoms(constipation, diarrhea, sweat, urine, vomiting), we are known that cold and heat connception of the each symptome is fixed, according to nature of cold and heat in each type. These express the methood of 'constitutional demonstration'.

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Prediction of Broadband Noise for Non-cavitation Hydrofoils using Wall-Pressure Spectrum Models (벽면변동압력을 이용한 비공동 수중익의 광대역소음 예측 연구)

  • Choi, Woen-Sug;Jeong, Seung-Jin;Hong, Suk-Yoon;Song, Jee-Hun;Kwon, Hyun-Wung;Kim, Min-Jae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.6
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    • pp.765-771
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    • 2019
  • With the increase in the speed of ships and the size of ocean structures, the importance of flow noise has become increasingly critical in meeting regulatory standards. However, unlike active investigations in aeroacoustics fields for airplanes and trains, which are based on acoustic analogy methods for tonal and broadband frequency noise, only the discrete blade passing frequency noise from propellers is considered in marine fields. In this study, prediction methods for broadband noise in marine propellers and underwater appendages are investigated using FW-H Formulation1B, which can consider the mechanism of primary noise generation of trailing edge noise. The original FW-H Formulation 1B is based on the pressure correlation function tolackitsgeneralityandaccuracy. To overcome these limitations, wall-pressure spectrum models are adopted to improve the generality in fluid mediums. The comparison of the experimental results obtained in air reveals that the proposed model exhibits a higher accuracy within 5 dB. Furthermore, the prediction procedures for broadband noise for hydrofoils are established, and the estimation of broadband noise is conducted based on the results of the computational fluid dynamics.

Evaluation of carbon flux in vegetative bay based on ecosystem production and CO2 exchange driven by coastal autotrophs

  • Kim, Ju-Hyoung;Kang, Eun Ju;Kim, Keunyong;Jeong, Hae Jin;Lee, Kitack;Edwards, Matthew S.;Park, Myung Gil;Lee, Byeong-Gweon;Kim, Kwang Young
    • ALGAE
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    • v.30 no.2
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    • pp.121-137
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    • 2015
  • Studies on carbon flux in the oceans have been highlighted in recent years due to increasing awareness about climate change, but the coastal ecosystem remains one of the unexplored fields in this regard. In this study, the dynamics of carbon flux in a vegetative coastal ecosystem were examined by an evaluation of net and gross ecosystem production (NEP and GEP) and $CO_2$ exchange rates (net ecosystem exchange, NEE). To estimate NEP and GEP, community production and respiration were measured along different habitat types (eelgrass and macroalgal beds, shallow and deep sedimentary, and deep rocky shore) at Gwangyang Bay, Korea from 20 June to 20 July 2007. Vegetative areas showed significantly higher ecosystem production than the other habitat types. Specifically, eelgrass beds had the highest daily GEP ($6.97{\pm}0.02g\;C\;m^{-2}\;d^{-1}$), with a large amount of biomass and high productivity of eelgrass, whereas the outer macroalgal vegetation had the lowest GEP ($0.97{\pm}0.04g\;C\;m^{-2}\;d^{-1}$). In addition, macroalgal vegetation showed the highest daily NEP ($3.31{\pm}0.45g\;C\;m^{-2}\;d^{-1}$) due to its highest P : R ratio (2.33). Furthermore, the eelgrass beds acted as a $CO_2$ sink through the air-seawater interface according to NEE data, with a carbon sink rate of $0.63mg\;C\;m^{-2}\;d^{-1}$. Overall, ecosystem production was found to be extremely high in the vegetated systems (eelgrass and macroalgal beds), which occupy a relatively small area compared to the unvegetated systems according to our conceptual diagram of a carbon-flux box model. These results indicate that the vegetative ecosystems showed significantly high capturing efficiency of inorganic carbon through coastal primary production.

The Antioxidants Activities of Hot-Water Extracts of Wa-song (Orostachys japonicus A. Berger) on Edible oil and Fat (식용유지에 대한 와송 열수추출물의 항산화효과)

  • Shin, Jung-Hye;Lee, Soo-Jung;Cha, Ji-Young;Seo, Jong-Kwon;Cheon, Eun-Woo;Sung, Nak-Ju
    • Korean journal of food and cookery science
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    • v.24 no.6
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    • pp.748-756
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    • 2008
  • This study was conducted to investigate the antioxidant activity of hot water extracts of wa-song (Orostachys japonicus A. Berger) dried using hot air (HWE) and frozen (FWE). Varying levels (0.1, 0.5 and 1.0 g/100 g) of HWE and FWE were added to soybean oil and lard. Chromaticity, anisidine value, acid value, peroxide value (POV) and thiobarbituric acid (TBA) value in oils were measured periodically during their storage for 28 days at $60^{\circ}C$. The chromaticity of edible oils showed a general increas with prolonged storage as well increasing levels of extracts. The anisidine value was not significantly increased during storage for 14 days, but was significantly increased after storage for 21 days in soybean oil and lard. The anisidine value of HWE on soybean oil was $12.60{\pm}0.92{\sim}13.82{\pm}0.68$ after storage for 28 days its value was lower than that of the control and buthylated hydroxy anisol (BHT). The antioxidant activity of HWE was found to be more effective than that of FWE. The acid value of HWE was significantly increased during storage from 14 to 21 days in soybean oil and from 7 to 14 days in lard. The antioxidant activity of FWE was particulary effective at the primary stage of the reaction system of lard storage. POV was highly increased during the storage periods between 7 and 14 days in soybean oil. The antioxidant activity in all the samples tested did not significantly increase after storage for 14 days, except when 0.1 g/ 100 g of FWE added to lard. TBA values of all the samples were lower than that of control and 0.02% BHT during their storage. The antioxidant activities of wa-song within the reaction system of oils were more effective in soybean oil than in lard.

Severe Nephritic-nephrotic Syndrome with Small Bowel Perforation in a Child with $Henoch-Sch\ddot{o}nlein$ Purpura (신염-신증후군과 소장 천공을 동반한 $Henoch-Sch\ddot{o}nlein$ 자반증 1례)

  • Kim, Gun-Ha;Shin, Hye-Kyung;Yim, Hyung-Eun;Hong, Young-Sook;Lee, Joo-Won;Won, Nam-Hee;Yoo, Kee-Hwan
    • Childhood Kidney Diseases
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    • v.11 no.1
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    • pp.106-111
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    • 2007
  • [ $Henoch-Sch\ddot{o}nlein$ ] Purpura(HSP) is a form of vasculitis that typically affects small arteries in the skin, joints, intestinal tract and kidneys. It usually resolves spontaneously but sometimes can cause serious problems in the kidneys and intestinal tract. A 6-year-old girl with purpura, arthralgia and abdominal pain for 2 weeks was admitted. She also showed gross hematuria, generalized edema and decreased urine output. Blood pressure was in the upper normal range. Initial laboratory findings showed hypoalbuminemia, hyperlipidemia, microhematuria and nephrotic-range proteinuria(27.2 g/day). Initially, she was treated with pulse methylprednisolone, azathioprine, albumin and furosemide. Her renal biopsy revealed diffuse mesangial proliferation with strong IgA deposition. There were no crescents. On the third hospital day, she complained of severe abdominal pain and free peritoneal air was seen on abdominal X-ray. Primary repair of small bowel was performed and two pin-point sized holes were found. One week later, she still showed heavy proteinuria. Therefore, we added an ACE inhibitor and dipyridamole, and changed azathioprine to cyclosporine. One month later, the urine protein/creatinine ratio was decreased to 17.8 from 57, but heavy proteinuria has been still persisted. Here we report a rare case of a patient with HSP who had both severe nephrritc-nephrotic syndrome and small bowel perforation.

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A Study on the Health Care Management of Industries in Seoul (서울지역 산업장의 보건관리)

  • Jung, Yeun-Gang;Park, Shin-Ae;Lee, Na-Mi;Yoon, Soon-Young;Kim, Young-Im;Wang, Myoung-Ja;Lee, Soon-Nam;Kim, En-Hee;Ko, Young-Ae
    • Research in Community and Public Health Nursing
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    • v.4 no.1
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    • pp.5-13
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    • 1993
  • The objective of this study was to analyze the status of health examination, and the health care management of industries in Seoul. This will provide effective industrial health care services. 46 industries were selected as a sample, and were given self administered questionnaire developed by the academic affairs of community health nursing. The results of this study are as follows: (1) The general characteristics of industries: The greater part of the industries were manu facturing companies, 300-900 workers, in a one shift system. (2) The general characteristics of health man ager: 96% of the companies had industrial nurses and the larger industries had comprehensive health managers. 90% of the industrial nurses were full-time employees and 77% of the industrial physician were part time employees. 80% of the industrial physician were age 50 or older, while 59% of the industrial nurses were 25-29 years of age. (3) Health examination and follow up care: The proportions of the workers who took general health examination was 94%. Of those, 12% took secondary examinations. In secondary examinations, 36% were evaluated at the C-grade, 20% were evaluated at the D-grade. The proportion of the workers who were required to take special examination were 29% and of that, the proportion of the workers who actually took the examination was 88%. 85% of the workers who were recommended for follow up cares were given follow up care while working. The physical agents among the special examination were done the most frequently to detect the examination effects. (4) Health care services: Industrial nurses performed health examination most frequently and health education was done the least. There were significant differences in health care services according to the size of the industries. Companies with 300 workers or less had higher health care services than other groups. The three primary reasons of health care management and examinations of workers are: First, industrial nurses are requires to accumulate professional knowledge and experience through continuos' activities. Second, systematic and concert examination for industrial workers should be performed periodically. Third, it needs developing health education strategies that are important workers for health promotion in industries.

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