http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
입구 유량변화에 따른 메가 집열기 지관의 유량분포특성에 대한 수치해석
김휘동(Kim Hwi-Dong),백남춘(Baek Nam-Choon) 한국태양에너지학회 2009 한국태양에너지학회 학술대회논문집 Vol.- No.-
Flow distribution characteristics with varying inlet flow-rate in mega collector risers have been investigated, using commercial code FLUENT. The heat transfer in mega collector was not considered in this numerical study. Through the simulation, the following results were found. First, flow distribution characteristics in mega collector risers show the similar tendency in all cases. Secondly, with increased inlet flow-rate, flow distribution uniformity was getting worse.
김휘동(Kim, Hwi-Dong),김기훈(Kim, Ki-Hoon),안지영(Ahn, Ji-Young),김수형(Kim, Soo-Hyung) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.11
In order to improve the overall power conversion efficiency, it is very important to reduce the interface resistance of dye-sensitized solar cells (DSSCs). In this approach, tiny TiO₂ nanoparticles with the primary size of 10~20nm were synthesized and deposited between FTO glass and preformed TiO₂ layer by TiOCl₂ treatment, and also Pt catalysts were deposited on the counter electrode by both ion-sputter and thermal deposition to reduce the electrolyte-counter electrode interface resistance. The influence of these processes on the performace of DSSCs were discussed in terms of fill factor, short circuit current, and conversion efficiency.
김휘동,구혜원,곽문석,김종렬,손병철,문덕환,이종태,조규일,엄상화,정귀옥,전진호,이채언,Kim, Hwi-Dong,Koo, Hye-Won,Kwak, Moon-Suk,Kim, Jong-Ryul,Son, Byung-Chul,Moon, Deog-Hwan,Lee, Jong-Tae,Cho, Kyu-Il,Ohm, Sang-Hwa,Jung, Kui-Oak,Chun, Jin 대한예방의학회 1996 Journal of Preventive Medicine and Public Health Vol.29 No.4
This study surveyed and measured the level and structure of cancer deaths and their trends over time for offering the fundamental data of e cancer prevention and control in Pusan city in the future. Authors conducted the study of descriptive epidemiology using materials derived from the computerized data of total 3,722 certified cancer deaths in Pusan city from January 1 to December 31, 1993 registered on the National Statistical Once, the Republic of Korea. The obtained results were as follows: 1. According to the total registered cases of deaths(16,331 cases) in Pusan city during 1993, cancer(3,722 cases) and cerebrovascular disease(2,118 cases) were the first and second cause of deaths as 23.1% and 16.9%, respectively. These pattern showed the change between cancer (14.7%) and cerebrovascular disease(18.5%) in order of frequency in comparison to 1982. Also, the total number of cancer deaths was increased in comparison to 1982. The rate of death certification by physicians was 87.1% of all registered deaths, which was increased to 6.8% in comparison to 1982(80.3%). 2. Crude death rate and cancer specific death rate was 4.06 per 1,000 populations and 93.8 per 100,000 populations(male:117.8, female:70.0), respectively. The former was similar to that of 1982, but the latter was increased to 1.6 times as that of 1982. 3. Age-adjusted cancer specific death rate by standardization with whole country population was 111.9(male:141.5, female:106.7) per 100,000 populations, higher than not age-adjusted cancer specific death rate(93.8), and the sex difference was statistically significant with male predominance (p<0.05). 4. Cancer specific death rate by age was generally increased with age and most of cancer deaths(male:91.8%, female:88.5%) occurred since 40 years old. 5. The major cancer(cancer specific death rate per 100,000 populations) in male was liver(30.6) followed by stomach(25.6), lung(21.9), and GB and EHBD(5.7), in female stomach(15.7), liver(9.9), lung(7.3), and uterus(6.9). The relative frequency of the leading three cancer among total cancer deaths marked 66.3% in male and 47.l% in female, and decreased in comparison to 1982(male:72.2%, female:54.5%). 6. The total ratio of male to female cancer specific death rate showed 1.68 to 1 with male predominance. And the ratio was above 2.0 in larynx, oral cavity & pharynx, esophagus, liver, lung, bladder cancer and the ratio was $1.0\sim1.9$ in stomach, pancreas, gall bladder and EHBD, brain, rectum and anus cancer, leukemia, but the ratio was reversed in thyroid and colon cancer. In conclusion, cancer was the first cause of deaths. The proportion of lung cancer was increased, that of stomach & uterine cancer was decreased relatively, and liver cancer was constantly higher proportion. In the future, it is necessary to conduct the further investigations on the cancer risk factors considering areal specificity.
직업적으로 소음에 노출되는 근로자들에서 청력의 비대칭성
김욱태 ( Wook Tae Kim ),김대환 ( Dae Hwan Kim ),이채관 ( Chae Kwan Lee ),안진홍 ( Jin Hong Ahn ),이창희 ( Chang Hee Lee ),김휘동 ( Hwi Dong Kim ),김정호 ( Jeong Ho Kim ),손병철 ( Byung Chul Son ),이종태 ( Jong Tae Lee ) 한국산업위생학회 2007 한국산업보건학회지 Vol.17 No.2
Usually equal noise exposure is considered to cause symmetrical hearing loss, but some screening audiometries of employees who were exposed to noise showed asymmetry. Therefore, this study was carried out to evaluate the distribution of asymmetrical hearing loss and the difference of air conduction level between left and right ear at the different frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000 Hz). Study subjects were 326 male employees who had participated in the noise-specific health examination from May to October, 2002. They were evaluated by otoscopic examination, pure tone audiometry and tympanometry. In all frequencies, hearing threshold level of left ear was worse than right ear. The mean interaural threshold differences between two ears were 0.83 dB at 500 Hz, 1.18 dB at 2,000 Hz, 2.29 dB at 3,000 Hz, 2.18 dB at 4,000 Hz, and statistically significant (p<0.05). The hearing loss of left ear was greater than right ear in occupationally noise-exposed workers. It is believed that left ear was more susceptible to noise damage than right ear.
Bisphenol A가 흰쥐의 태반 기능과 출산에 미치는 영향
이채관,김석현,문덕환,김정호,손병철,김대환,이창희,김휘동,김정원,김종은,이채언,Lee, Chae-Kwan,Kim, Seog-Hyun,Moon, Deog-Hwan,Kim, Jeong-Ho,Son, Byung-Chul,Kim, Dae-Hwan,Lee, Chang-Hee,Kim, Hwi-Dong,Kim, Jung-Won,Kim, Jong-Eun,Lee, Chae 대한예방의학회 2005 예방의학회지 Vol.38 No.3
Objectives : The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats ($160g{\pm}20g$) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group. Conclusions : BPA disrupts the placental functions in rats, which leads to reproductive disorders.