• 한국대기환경학회지
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• 제12권4호
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• pp.399-406
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• 1996

Acidic fog is catastrophic to aviation and potentially affect materials, vegetation, crops and public health. This paper was carried out to investigate the chemical features of fog sample at Mt. Sobaek (mean sea level : 1, 340m) from June to August 1995. Each sample was analyzed for pH, electrical conductivity and major ions (anion : $Cl^N)_3^-, SO_4^{2-}, cation : Na^+, NH_4^+, K^+, Mg^{2+}, Ca^{2+}$) by ion chromatography. The quality analysis of fog sample data was performed based on ion balance and electrical conductivity method. The wind directions are subdivided into the northerly and southerly wind according to the wind direction data at the Sobaek-san meteorological observation station. Statistical analyses were performed on the complete set of results in order to obtain a description of fog sample. All the statistical treatment was carried out using the SPSS/PC + software package. The major ion concentration of fog samples was higher for the northwesterly wind cases than sourtheasterly wind cases. The pH of fog sample varied between 2.95 and 6.08. The average pH and electrical conductivity of total sample (n=210) were 4.39 and 113.0 $\mu$S/cm, respectively. It may be noted that in nearly all the cases, the dominant major ions in the fog sample at Mt. Sobaek were $SO_4^{2-}, NO_3^-, H^+ and NH_4^+$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.255-257
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• 2001

In this paper, the silicon rubber insulator for transmission line was experimented for 1,000 hours aging test in salt-fog condition. To evaluate and examine the aging properties of silicon rubber insulator for test, the leakage current of surface was measured. Also hydrophobicity and scanning electron microscopy were compared with initial and aged sample respectively Above results, we can confirm that the surface properties of silicon rubber insulator easily aged by salt-fog condition.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.255-257
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• 2001

In this paper, the silicon rubber insulator for transmission line was experimented for 1,000 hours aging test in salt-fog condition. To evaluate and examine the aging properties of silicon rubber insulator for test, the leakage current of surface was measured. Also hydrophobicity and scanning electron microscopy were compared with initial and aged sample respectively. Above results, we can confirm that the surface properties of silicon rubber insulator easily aged by salt-fog condition.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.25-28
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• 1998

In this study, we investigated the electrical characteristics of silicone rubber that being used outdoor insulating material, which had been immersed in salt water. After immersed the sample in salt water, we measured surface hydrophobicity, weight loss and microscopic surface appearance, and then compared with these of the original. And we tested the electrical characteristics of the aged sample by the water under salt-fog. These electrical characteristics are described by the average of leakage current, peak pulse number, which are recorded by data acquisition system The experimental results show that the resistance against tracking and erosion is decreased significantly by water penetration.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.598-606
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• 2000

In this paper we investigated the relation between the surface degradations and anti-pollution characteristics of Room Temperature Vulcanized(RTV) silicone rubber coating that has different roughness through immersing into saline water. We utilized several analytic techniques such as atomic force microscopy(AFM) scaning electron microscopy(SEM) contact angle Salt Deposit Density(SDD) and average leakage current under the condition of salt fog. It is found that the surface roughness of treated RTV silicone rubber increased and the hydrophobicity of sample surface decreased with increasing the duration o immersion into water due to the erosion of base polymer the melting down alumina trihydrate(ATH) and the diffusion of Low Molecular weight(LMW) fluid. Despite the roughness of surface had been increased by water immersion excellant anti-pollution and recovery characteristics were maintained and SDD saturated to 0.1~0.14mg/cm$^2$. The average leakage current under salt fog increased with surface roughness. Measurement of average leakage current will be helpful to investigate surface degradation and lifetime expectation of RTV silicone coating.

• Asian Journal of Atmospheric Environment
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• 제11권1호
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• pp.54-60
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• 2017

Quantifying the trace elements in infinitesimal ambient liquid samples (e.g., single raindrop, cloud/fog water, and the soluble fraction extracted from the particles collected for a short time) is an important task for understanding formation processes, heating/cooling rates, and their health hazards. The purpose of this study is to employ an in-air micro PIXE system for quantitative analysis of the trace elements in a thimbleful of reference liquid sample. The bag type liquid sample holder originally designed with $10{\mu}m$ thick $Mylar^{(R)}$ film retained the original shape without any film perforation and apparent peaks of film blank by the end of the analysis. As one of tasks to be solved, the homogeneity of the elemental distribution in liquid reference species was verified by the X-ray line profiles for several references. It was possible to resolve the significant peaks for whole target elements corresponding to the channel number of micro-PIXE spectrum. The calibration curves for the six target elements (Si, S, Cl, Fe, Ni, and Zn) in standard solutions were successfully plotted by concentration (ppm) and ROI of interest net counts/dose (nC).

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.1-10
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• 1999

In this paper, we have investigated the effects of the environmental factors on Low Molecular Weight (LMW) silicone fluid contents existing in high temperature vulcanized (HTV) silicone rubber sample, using dipping method and contact angle, current measurement. Artificial treatments such as immersion in water, elevated temperature, UV irradiation and dry band arcing under salt-fog condition are selected as the environmental factors. This results will be helpful to investigate the degradation with time and to expect a life time, because the LMW silicone content, which is important to recovery the hydrophobicity of silicone rubber surface, show different results by each environmental factors.

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.330-346
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• 1997

다목적 실용위성 1호 (KOMPSAT I)는 지도 제작, 해양관측, 우주 과학실험 등에 활용할 태양도기 저궤도용 위성으로 1999년 8~9월에 발사될 예정이다. 본 위성에 탑재될 고해상도 전자광학 카메라(Electro-Optical Camera: EOC)의 주임무는 한반도 표준지도 제작을 위한 위성영상정보의 획득이다. EOC 센서는 가시광선 영역의 흑백 단일 채널(510~730mm)을 통해 수직 촬영 시 최소 15km 이상의 폭과 궤도 800km의 길이를 지상 해상도 6.6m로 촬영한다. 본 연구에서는 아리랑 1호의 한반도 통과 시각을 결정하기 위하여 한반도 지역에 있어 EOC 영상에 커다란 영향을 미치는 태양 변수와 구름과 시정의 일변를 조사하였다. 조사 결과는 다음과 같다. 1) 동지의 경우 대략 오전 10시 30분 이후 태양 천장 각 의 $70^{\circ}$보다 작고, 예상되는 EOC 스펙트럼 밴드의 flux 값은 맑은 날씨 육지에서 약 $2.4mW/cm^2$보다 크다. 2) 낮 동안의 구름의 분포 (맑은 하늘의 분포)는 오전 11시경에 최소값(최대값)을 보이며, 비록 안개에 의한 악 시정의 발생 빈도는 정오로 갈수록 감소하나 맑은 하늘의 분포에 미치는 영향은 미약하다. 이러한 결과로부터 EOC 관측을 위해서는 다목적 실용위성 1호의 한반도 통과 시각을 오전 10시 30분에서 11시 30분 사이에서 결정하는 것이 적합하다고 판단된다.

• 대한간호학회지
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• 제5권1호
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• pp.1-16
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• 1975

The newborn human is the only mammalian whose mother does not have a food supply ready for it's offspring at birth. From two to four days usually elapse before the mother's supply If milk appears, and during this period, some kind of artificial feeding should be supplied to the infants. Because of this factor, there has been continued debate fog the past hundreds of years as to when the first feeding should be started Accordingly, many experiments were carried out by scholars and because of these, Pre-lateral feedings were believed to be necessary. Many types of pre-lateral feedings were tried and the conclusion was reached that glucose water was the best food for the first infants'feedings. Traditionally, This has been started 12 hours after birth. The causes for the 12 hours delay were thought to (1) provide rest for the infants: (2) prevent regurgitation ana vomiting which tended to be prevalent during this tine: (3) in cases of low weight infants, prevention of aspiration pneumonia. From recent studies of newborn physiology and as pediatric medicine has been rapidly advancing, many studies hare been carried out concerning the improvement of infant nutrition and the early feeding of infants has been emphasized. This author believes it would be very beneficial to try two different kinds of feedings for the infant. (1) experimental feedings ana (2) comparative feeding, and during this period to investigate and compare the infants blood sugar level, hematocrit, gamma globulin level weight changes and to observe the infant reaction ill order to search for a more desirable feeding program. This study was conducted from January to March 1974 with data related to 40 healthy newborn infants (male 21, female 19: weight, 2.79∼4.20㎏ : gestation, 39∼40 weeks) born at Ewha Womens University Hospital and the results obtained were as follows : 1. At time of birth the blood sugar level from the cord sample averaged 88.99㎎/100㎖, but the blood sugar level rapidly dropped after 2 to 3 hours and reached the lowest point after 10 to 11 hours (54.48㎎/100㎖) and rose again by the 24 hour time period (76.80㎎/100㎖). Changes in the blood sugar level of the experiments: groups and the compare-five group was not significantly different until the 6 to 7 hour period, but by the 10 to 11 hour period the blood sugar levels of the experimental group (49,10㎎/100㎖) and the comparative group (49.70㎎/100㎖) were lower than the remainder of the experimental groups. 9. There ware no significant weight changes between the two groups. Average weight at birth was 3.35㎏, but at the 24 hours period birth weight averaged 3.29㎏. (1.8% reduction of birth weight). It continually lowered until at 48 hours, average weight was 3.26㎏ (2.7% reduction from birth weight.) 3. Hematocrit readings showed no significant difference between the groups. Hematocrit, the average value at birth, was 28.07% and abruptly elevated to average 64.35% at the 2 to 3 hour period, then slowly lowered to an average of 59.67% at the 6 to 7 hour period, 55.10% at the 10 to 11 hour period, ana 53.70% at the 24 hour period. 4. At birth, average gamma globulin value averaged 1,39㎎/100㎖. and at the 24 hour period averaged 1,52㎎/100㎖ revealing no significant difference between the two feeding groups. 5. Such factors as voiding, passing of meconium, regurgitation and vomiting showed no significance between the two feeding groups. However, the number of infants voiding and passing meconium in the experimental groups during the first 12 hours was slightly greater. In general there was an increased tendency for regurgitation and. vomiting among a small group of the infants during the first 24 hours which thereafter decreased. 6. Fluid intake averaged 24.38cc at the first feeding and increased to average 30.48cc at the third feeding and further increased to 73. 00cc at the fifteenth feeding. Finally it was suggested that the most reasonable method of early feeding is to give less than 25cc of 5% glucose water and/or 8% powdered milk at 8 to 9 flours after birth in order to prevent hypoglycemia and dehydration.