• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.4
• /
• pp.337-346
• /
• 2014

This study aimed to understand the mode characteristics of a droplet subject to periodic forced vibration and the detachment of a droplet placed on a plate surface. An surface was coated with Teflon to clearly observe the behavior of a droplet. The contact angle between the droplet and surface and the hysteresis were found to be approximately $115^{\circ}C$ and within $25^{\circ}C$, respectively. The coating process was performed in a clean room that had an environment with a low level of contaminants and impurities such as air dust, detergents, and particles. To predict the resonance frequency of a droplet, theoretical and experimental approaches were applied. Two high-speed cameras were configured to acquire side and top views and thus capture different characteristics of a droplet: the mode shape, the detachment, the separated secondary droplet, and the waggling motion. A comparison of the theoretical and experimental results shows no more than 18 discrepancies when predicting the resonance frequency. These differences seem to be caused by contact line friction, nonlinear wall adhesion, and the uncertainty of the experiment. For lower energy inputs, the contact line of the droplet was pinned and the oscillation pattern was axisymmetric. However, the contact line of the droplet was de-pinned as the oscillation became more vigorous with increased energy input. The size of each lobe at the resonance frequency is somewhat larger than that at the neighboring frequency. A droplet in mode 2, one of the primary mode frequencies, exhibits vertical periodic movement as well as detachment and secondary ejection from the main droplet.

• Korean Journal of Food Science and Technology
• /
• v.48 no.6
• /
• pp.582-589
• /
• 2016

The aim of this study was to investigate the synergistic anti-inflammatory and anti-dermatitis effects of grape branch extract (GBE) and Pleurotus eryngii (PEE) combinations on the active immune cells and atopic dermatitis-like skin lesions in mice. The results showed that the combination of GBE ($12.5{\mu}g/mL$) and PEE ($500{\mu}g/mL$) led to much stronger inhibitory effects on the production of inflammatory mediators, such as NO and $PGE_2$ than that exhibited by GBE ($25{\mu}g/mL$) and PEE ($1000{\mu}g/mL$) alone, even at higher concentrations, in LPS-stimulated RAW 264.7 macrophages. The combination of GBE and PEE synergistically inhibited the production of TNF- and IL-6 in LPS-stimulated RAW 264.7 macrophages and PMA plus A23187-activated HMC-1 cells. Furthermore, combined GBE and PEE had a stronger ameliorative effect than GBE and PEE alone by inhibiting the clinical sores, IgE, and IL-4 on atopic dermatitis-like skin lesions in mice. Collectively, these results suggested that the combination of GBE and PEE produced a synergistic anti-inflammatory and anti-atopic dermatitis effect on immune cells and atopic dermatitis-like skin lesions in mice.

• Journal of Conservation Science
• /
• v.29 no.4
• /
• pp.333-343
• /
• 2013

The exhibition hall of museum has been damaged by abundant dust and mold of the air in the room. Occurrence of microorganisms on the surface of the cultural heritage will cause damages such as coloration, materials degradation, deterioration, etc. In this study, we investigated the temperature/humidity and microbes distribution in exhibition hall, display showcase, and on surface of wall paintings in the Muwisa museum. From some samples collected in exhibition hall and display showcase, we identified so many varieties of micro-organisms such as Aspergillus sp., Penicillium sp., Cladosporium sp.. In particular, we could see a large number of microorganisms in the number 1, 2 exhibition hall compared with the number 3 exhibition hall. The results examining the distribution of the temperature and humidity were showed as $28{\pm}4^{\circ}C$ and 70~80%, respectively. The number 1 exhibition showcase was higher humidity environment than the number 2, 3 exhibition hall compared to the distribution ratio, which considered as correlation with the distribution of microorganism concentration. As these results, we understood that high temperature and humidity in the exhibition hall and display showcase of the Muwisa museum were characteristics caused by environmental management and hermetically-sealed rooms.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.44 no.2
• /
• pp.111-116
• /
• 2018

In cosmetics market, anti-pollution products recently come up with new solution for skin health. Environmental oxidation mechanisms are realized as bio-marker of atmospheric pollution upon skin by environmental pollutant such as ozone, UV rays, particulate matter (PM) as well as cigarette smoke. The exposure of cigarette smoke directly or indirectly causes the oxidation of the stratum corneum skin lipids, resulting in the conversion of squalene to squalene monohydroperoxide and/or generation of malondialdehyde (MDA) as a product of lipid peroxidation. The aim of this study is to see whether new cosmetics product containing red beet has anti-oxidation effect on skin exposed by cigarette smoke. So as to determine oxidative damage to human skin at biochemical level, each unit area of volar forearms was exposed to cigarette smoke through device (3.3 cm, diameter) for fifteen minutes, then measured MDA using standardized TBARS assay kit. Compared to negative control (untreated and unexposed area), the level of MDA was significantly increased at positive control (untreated and exposed area) more than 3.7 times, indicating the pollutant induced-oxidative damage on the skin barrier. Whereas, the pre-applied area with the cosmetics products containing red beet revealed a decrease of 25% compared with positive control. As reports, these data demonstrated that cigarette smoke induce peroxidation of stratum corneum skin lipids. Conclusively, we suggest that anti-pollution effect of the cosmetics product containing red beet is beneficial to prevent the oxidation of skin lipids by atmospheric pollution.

• Clinical and Experimental Pediatrics
• /
• v.51 no.8
• /
• pp.868-873
• /
• 2008

Purpose : Immunotherapy is accepted as the only treatment of allergic disease that can modify the natural course of the disease and ameliorate symptoms. This study aimed to evaluate the safety and efficacy of ultra-rush therapy using Dermatophagoides extracts in children. Methods : Of children older than four years who had visited Bundang CHA Pediatric Allergy Clinic, those showing positive reactions only to Dermatophagoides in the skin prick test and to the nasal provocation test were included. In all, 11 and 12 patients respectively preferred conventional and ultra-rush immunotherapy. We elevated allergen concentrations diluted to 1,000:1 of the end strength by 2-3 times with 30-minute intervals and checked oxygen saturation, pulse rate, blood pressure, and systemic reactions every 15 minutes. Immunotherapy effectiveness was valued by changes in nasal provocation test scores before and after immunotherapy. Results : The average ages of patients in the conventional and ultra-rush immunotherapy groups were $8.3{\pm}2.3$ and $9.2{\pm}2.8years$, respectively. Systemic reactions were observed in six in the ultra-rush group (50%) without anaphylaxis and one (9%) in the conventional group. The average scores in the nasal provocation test before and after treatment in the conventional group were $8.2{\pm}1.5$ and $4.6{\pm}2.1$, respectively (P=0.043). In the ultra-rush immunotherapy group, the scores changed from $6.2{\pm}2.2$ to $3.7{\pm}2.5$ (P=0.017). Conclusion : Ultra-rush immunotherapy using Dermatophagoides in children is effective for treating allergic disease but can induce systemic effects rather than conventional immunotherapy.

• Radiation Oncology Journal
• /
• v.23 no.4
• /
• pp.243-252
• /
• 2005

Purpose: Indoor air quality (IAQ) in the radiation treatment center which is generally located underground is important to the health of hospital workers and patients treated over a long period of time. this study was conducted to measure and analyze the factors related to IAQ and subjective symptoms of sick building syndrome, and to establish the causes influencing IAQ and find a solution to the problems. Methods and Materials : Self administrated questionnaire was conducted to check the workers' symptoms and understanding of the work environment. Based on a preliminary investigation, the factors related to IAQ such as temperature, humidity, fine particulate. carbon dioxide, carbon monoxide, formaldehyde, total volatile organic compounds (TVOC), and radon gas were selected and measured for a certain period of time in specific sites where hospital workers stay long in a day. And we also evaluated the surrounding environment and the efficiency of the ventilating system simultaneously, and measured the same factors at the first floor (outdoor) to compare with outdoor all quality, All collected data were assessed by the recommended standard for IAQ of the domestic and international environmental organizations. Results: Hospital workers were discontented with foul odors, humidity and particulate. They complained symptoms related to musculo-skeletal system, neurologic system, and mucosal-irritatation. Most of the factors were not greater than the recommended standard, but the level of TVOC was third or fourth times as much as the measuring level of some offices in the United States. The frequency and the amount of the ventilating system were adequate, however, the problem arising in the position of outdoor-air inlets and indoor-air outlets involved a risk of the indraft of contaminated air. A careful attention was a requirement in handling and keeping chemical substances including a developing solution which has a risk of TVOC emissions, and repositioning the ventilating system was needed to solve the contaminated-air circulation immediately Conclusion We verified that some IAQ-related factors and inadequate ventilating system could cause subjective symptoms in hospital workers. The evaluation of IAQ was surely needed to improve the underground working environments for hospital workers and patients. On the basis of these data, from now on, we should actively engage in designs of the department of radiation oncology or improvement in environments of the existing facilities.

• Journal of the Korean association of regional geographers
• /
• v.23 no.1
• /
• pp.151-167
• /
• 2017

The main objective of this study was to investigate the climatic impact of $PM_{10}$ concentration on the temperature change pattern in Busan Metropolitan City(BMC), Korea during 2001~2015. Mean $PM_{10}$ concentration of BMC has gradually declined over the past 15 years. While the highest $PM_{10}$ concentration was observed in spring followed by winter, summer, and fall on average, the seasonal variations of $PM_{10}$ concentration differed from place to place within the city. Frequency analysis showed that the most frequently observed $PM_{10}$ concentration ranged from $20{\mu}g/m^3$ to $60{\mu}g/m^3$, which accounted for 64.6% of all daily observations. Overall, the west-high and east-low pattern of $PM_{10}$ concentration was relatively strong during the winter when the effect of yellow-dust events on the air quality was weak. Comparative analyses between $PM_{10}$ concentration and monthly temperature slope derived from generalized temperature curves indicated that the decreasing trend of $PM_{10}$ concentration was associated with increases of annual temperature range, and $PM_{10}$ concentration had a negative relationship with the temperature slope of warming months. Overall, $PM_{10}$ concentration had a weak correlation with the annual mean temperature, but it had a significant, positive correlation with the winter season, which had a dominant influence on the annual mean temperature. In terms of energy budget, it has been known that the change in $PM_{10}$ concentration contributes to the warming or cooling effect by affecting the radiative forcing due to the reflection and absorption of radiant energy. The correlation between $PM_{10}$ concentration and temperature changes in the study area was not seasonally and spatially consistent, and its significance was statistically limited partly due to the number of observations and the lack of potential socioeconomic factors relevant to urban air quality.

• Journal of Life Science
• /
• v.32 no.4
• /
• pp.310-317
• /
• 2022

Recently, interest in the harmful factors of particulate matter (PM), a major component of air pollution, has been increasing. In particular, PM_2.5 with a diameter of less than 2.5 ㎛ is well known to induce oxidative stress accompanied by autophagy in human lung epithelial cells. However, studies on whether PM_2.5 increases autophagy under oxidative stress and whether this process is reactive oxygen species (ROS)-dependent are insufficient. Therefore, in this study, we investigated whether PM_2.5 promotes autophagy through the generation of ROS in human alveolar epithelial A594 cells. According to our results, cells co-treated with PM_2.5 and hydrogen peroxide (H₂O₂) showed a lower cell viability than cells treated with each alone, which was associated with increased total and mitochondrial ROS production. The co-treatment of PM_2.5 and H₂O₂ also increased autophagy induction, which was confirmed through Cyto-ID staining, and the expression of autophagy biomarker proteins increased. However, when ROS generation was artificially blocked by N-acetyl-L-cysteine pretreatment, the reduction in cell viability and induction of autophagy by PM_2.5 and H₂O₂ co-treatment were markedly attenuated. Therefore, the present results suggest that PM_2.5-induced ROS generation may play a critical role in autophagy induction in A549 cells.

• Journal of Animal Environmental Science
• /
• v.16 no.3
• /
• pp.205-215
• /
• 2010

Geothermal heat pump system (GHPS) is an energy-efficient technology that use the relatively constant and renewable energy stored in the earth to provide heating and cooling. With the aim of using GHPS as a heating source, it's possibilities of application in farrowing house were examined by measuring environmental assessment and sow's performance. A total of 96 sows were assigned to 2 pig housings (GHPS and conventional housing) with 48 for four weeks in winter season. During the experimental period, indoor maximum temperature in GHPS-housing was measured up to $26.7^{\circ}C$, average temperature could maintain $21.2^{\circ}C$. The mean value of dust levels and $CO_2$, $NH_3$ and $H_2S$ gas emissions were decreased in GHPS-housing compare with those of conventional housing. Litter size, birth weight, parity and weaning weight did not differ between housings. However, feed intake of sow in GHPS-housing was lower than that of conventional housing. In energy consumption for heating, electric power consumption increased in GHPS-housing than the conventional housing, a 2,250 kwh increase, whereas there is no fuel usage for heater in GHPS-housing. Amount of ground water circulated for heating in cold weather for earth heat exchanger was 8.4-12.9 ton per day. In conclusion, GHPS may have environmental benefits and effectiveness of heating in farrowing housing and affect the performance in sows.

• Journal of Environmental Science International
• /
• v.12 no.6
• /
• pp.665-676
• /
• 2003

To investigate the chemical characteristics of PM$\_$2.5/ in Seoul, Korea, atmospheric particulate matters were collected using a PM$\_$10/ dichotomous sampler including PM$\_$10/ and PM$\_$2.5/ inlet during the period of October 2000 to September 2001. The Inductively Coupled Plasma-Mass Spectromety (ICP-MS), ion Chromatography (IC) methods were used to determine the concentration of both metal and ionic species. A statistical analysis was performed for the heavy metals data set using a principal component analysis (PCA) to derived important factors inherent in the interactions among the variables. The mean concentrations of ambient PM$\_$2.5/ and PM/sub10/ were 24.47 and 45.27 $\mu\textrm{g}$/㎥, respectively. PM$\_$2.5/ masses also showed temporal variations both yearly and seasonally. The ratios of PM$\_$2.5/PM$\_$10/ was 0.54, which similar to the value of 0.60 in North America. Soil-related chemical components (such as Al, Ca, Fe, Si, and Mn) were abundant in PM$\_$10/, while anthropogenic components (such as As, Cd, Cr, V, Zn and Pb) were abundant in PM2s. Total water soluble ions constituted 30∼50 % of PM$\_$2.5/ mass, and sulfate, nitrate and ammonium were main components in water soluble ions. Reactive farms of NH$_4$$\^$+/were considered as NH$_4$NO$_3$ and (NH$_4$)$_2$SO$_4$ during the sampling periods. In the results of PCA for PM$\_$2.5/, we identified three principal components. Major contribution to PM$\_$2.5/ seemed to be soil, oil combustion, unidentified source. Further study, the detailed interpretation of these data will need efforts in order to identify emission sources.