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고도정수처리 공정에서의 천연유기물질 특성변화 및 소독부산물 전구물질의 제거특성 평가
노재순,손희종,박은주,황영도,최동훈,배석문,신판세 慶星大學校 環境問題硏究所 2002 環境硏報 Vol.12 No.1
In this research the movement and apparent molecular weight distribution of hydrophilic/hydrophobic organic matters in advanced water treatment process were investigated using the raw water of Maeri area, located in downstream of Nakdong river, and the variation of the disinfection by-product formation potential was also investigated. In the raw water used in experiments, the content of BDOC (biodegradable dissolved organic carbon) in dissolved organic carbon (DOC) was about 39%, and this value is far above a normal, Pre-ozone treatment showed an increase of 40% in the BDOC content, and this means that biodegradability was remarkably increased by ozone treatment BDOC concentration in BAC treated water was 0.09 mg/L, which means 84% of BDOC removal rate compared with that in post-ozone treated water. The variation of chlorine disinfection by-product formation potential in each process unit of water treatment process was analyzed. TOXFP concentration in raw water was 449 ㎍/L, and the contents of THMFP and HAAFP among TOXFP were 24% and 23%, respectively. The removabilities of these materials BAC process had an order of TOXFP > HAAFP > THMFP. BAC process was less effective for THMFP than others. The distribution of hydrophilic organic matters were evaluated in each treatment process. Hydrophilic and hydrophobic matters in the raw water had a ratio of 50 : 50, and the ozone treatment decreased the content of hydrophobic matters. The BAC treatment made the ratio 85:15. These mean that the removal of hydrophilic matters is more difficult than that of hydrophobic materials in water treatment process. In addition the portions of humic and fulvic acid in hydrophobic matters were analyzed. Fulvic acid a large portion among hydrophobic matters in the raw water, and the portion was 78%. Ozone treatment was more effective on the removal of fulvic acid than humic acid. After BAC treatment, the concentration of residual fulvic acid was high than humic acid. Chlorine disinfection by-product formation for hydrophilic and hydrophobic mattrts was compared in each process unit. in the raw water TOXFP and THMFP formation for hydrophobic matter was higher, and HAAFP was highly formated for hydrophobic matter. After post-ozone or BAC treatment, chlorine disinfection by-product formation has high potential for hydrophobic matters. Comparing humic and fulvic acids, chlorine disinfection by-product formation potential was higher for humic acid than for fulvic acid in all processes. In the comparison of the reactivity with chlorine disinfection by-product per unit DOC, THMFP and DOXFP showed higher reactivity with hydrophobic matter than with hydrophilic matter in all processes, and HAAFP was highly reacitive with hydrophilic matter. Apparent molecular weight distributions of organic matters were investigated in each process step.The content of low molecular weight organic matters less than 1000 Da in DOC was high in all processes except raw water, but molecular weight organic matters more than 1000 da was higher than molecular weight organic matters less than 1000 Da in the formation potential of chlorine disinfection by-product.
ZVS를 이용한 SEPP 고주파 공진 인버터의 특성해석
김동희,노채균,김종해,민병재,배상준 嶺南大學校 工業技術硏究所 1997 工業技術硏究所論文集 Vol.25 No.1
Applied the high frequency switching technology to the ower conversion circuits, the turn on and off loss of switch point out practically large the point at issue, in order to reduce switching loss, the switching method using tank resonant circuit be connected serial and parallel with load have been continuously investigated. This paper was described about principle and form of proposed circuit made use of soft switching technology ZVS(Zero Voltage Switching) and ZCS(Zero Current Switching) to reduce turn on and off loss at switching. Also, the analysis of the proposed circuit is described generally by using normalized parameter and basic operating principle and driving characteristics have been evaluated as to switching frequency and load parameter. Based on the charactristics value, a method of circuit design is proposed. In addition, Pspice's simulation and experimental waveforms are compared with theoretical ones. The experimental results shows that the proposed Inverter can be used practically such as power source system for induction cooker etc.
장자영,노순국,박종천,김재섭,박성렬,박창균 조선대학교 동력자원연구소 1996 動力資源硏究所誌 Vol.18 No.1
To predict accurately an antenna radiation pattern is very important for determining of a service area, base-station location, cell design. In this paper, we have calculated a propagation prediction data of Hata, Egri, Carey, Free Space Loss model by a computer simulation in Kwang-ju downtown, and the data is compared with field test data. As a results, Hata and Egri model are approached to field test data, but considerable errors are detected.Conclusively, we believe that the most accurate prediction model must propose to improve the radio propagation environments for the specified region. For resolve these problems, we are proposed a mew experimental radio wave propagation predict model.
Jae-Jong Noh,On-Sook Hur,Na-Young Ro,Jae-Eun Lee,Ae-Jin Hwang,Bit-Sam Kim,Ju-hee Rhee,Jung Yoon Yi,Ji Hyun Kim,Ho-Sun Lee,Jung-Sook Sung,Myung-Kon Kim,Awraris Derbie Assefa 한국자원식물학회 2020 한국자원식물학회지 Vol.33 No.6
High-quality and high-phytonutrient watermelon fruits have strong market opportunities besides their health related benefits. Hence, investigating quality and nutritional related traits of watermelon genetic resources could provide important baseline data in breeding for increased lycopene content thereby increasing the marketability of watermelon. To this end, we have examined some fruit morphological traits and lycopene content of 105 genetic resources. Seeds, originally obtained from 22+ countries, were obtained from the National Agrobiodiversity Center, Jeonju, South Korea, grown in an experimental field and harvested at a fully mature stage. The size of pistil scar (SPS), the width of stripes (WS), weight of fruit (WF), length of fruit (LF), width of fruit (WIF), the thickness of pericarp (TP), soluble solids content (SSC), fruit shape in longitudinal section, ground color of skin, the intensity of the green color of skin, fruit shape at the apical part, grooving distribution, conspicuousness of stripes, and main color of the flesh were recorded on the field and inside laboratory and the lycopene was measured using spectrophotometric and HPLC methods. Watermelon fruits have shown a diverse morphological characters. Red and pink fleshed fruits dominated in the entire collections. Fruits with higher thickness of rind were found to exhibit less soluble solid content (SSC). Korean origin fruits were characterized by intermediate SSC while the United States of America (USA), Russia (RUS), Tajikistan (TJK), Turkmenistan (TKM), Taiwan (TWN), and Uruguay (URY) originated fruits had the highest SSC. The lycopene content varied between 41.37 and 182.82 ㎍/g, 2.81 and 163.72 ㎍/g, and 3.54 and 255.47 ㎍/g using HPLC, UV-Vis spectrophotometer, and microplate reader spectrophotometer, respectively. Red- and pink-fleshed fruits had the highest levels of lycopene content compared to the yellow- and orange-fleshed. Lycopene content had a significant positive correlation with SSC, however, no correlations were detected between lycopene and other quantitative fruit morphological characters. Our study demonstrated high diversity exists in fruit morphological traits and lycopene content of the germplasm collections which provide beneficial baseline data for a future breeding program and utilization of watermelon germplasm collections in gene banks for the maintenance and improvement of the current levels of production, marketability, and health-related benefit of watermelon fruits.
노재홍 ( Jae Hong Noh ),이선주 ( Sun Joo Lee ),노정래 ( Cheong Rae Roh ),서용수 ( Yong Soo Seo ),황종대 ( Jong Dae Whang ),김영아 ( Young A Kim ),양순하 ( Soon Ha Yang ),김종화 ( Jong Hwa Kim ) 대한주산의학회 2002 大韓周産醫學會雜誌 Vol.13 No.1
Objective:To evaluate the causes, methods of delivery, and maternal complications in cases of fetal death in utero(FDIU) at Samsung Medical Center. Methods:There were 92 cases of FDIU among 25,195 deliveries at Samsung Medical Center during 7 years from 1994 to 2001. In these cases, perinatal autopsy and placental biopsy was performed in 35 and 71 cases, respectively. All the clinical informations were obtained by reviewing medical records retrospectively. Results:The overall incidence of FDIU was 0.37%. Most of FDIU occurred in 25 to 29 years old group(43.5%). Recurrence rate of FDIU was 3.3%. Most of FDIU were low birth weight(79.3%) and preterm(79.6%). The modes of delivery were induced labor(68.5%), laparotomy(18.5%), and the spontaneous delivery(13.0%). The causes of FDIU were chorioamnionitis(15.2%), placental abruption(14.1%), severe preeclampsia(11.9%), congenital and chromosomal anomaly(6.5%), but it was unexplained in 27.2%. There were 25 cases with maternal complications and the most common complications were intra-/postpartum fever(18.5%), postpartum hemorrhage(8.7%) and DIC(8.7%). Conclusion:The causes of FDIU could not be determined in only about 1/4 cases at Samsung Medical Center. Since FDIU recurred in 3.3%, thorough studies including perinatal autopsy and chromosomal study must be made on stillborn infants and placenta to determine the recurrent causes.