• Journal of Korean society of Dental Hygiene
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• v.18 no.5
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• pp.665-674
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• 2018

Objective: The purpose of this study was to reduce the burden on dental hygienists in performing dental hygiene processes in the clinic. This study systematically analyzed dental hygiene problems and dental hygiene planning according to the oral condition of patients by applying an oral health care program based on the dental hygiene process. Methods: This study analyzed influential factors of 17 dental hygiene problems and 12 dental hygiene plans according to the oral health index and charts of 185 patients. This study was approved by the Institutional Review Board (IRB No. 1041449-201801-HR-003) of Silla University. The frequency of dental hygiene problems and dental hygiene planning was analyzed and correlations among the oral health index, dental hygiene problems, and dental hygiene planning were analyzed. Results: The higher the bleeding on probing score was, the more scaling was planned. The higher the calculus rate was, the more air-jet and jaw joint disorder prevention education was planned. The higher the O'Leary index was, the more dietary education and air-jet was planned. The higher the Simplified Oral Hygiene Index was, the more air-jet and jaw joint disorder prevention education was planned. The higher the Periodontal Screening and Recording index was, the more scaling and professional tooth cleaning was planned (p<0.05). Conclusions: The burden of oral preventive duties on dental hygienists will be minimized by systematically establishing problems and planning of dental hygiene according to patients' oral health index scores. Therefore, it is expected that dental hygienist can actively use the dental hygiene process in oral health care programs.

• Asian Journal of Atmospheric Environment
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• v.11 no.4
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• pp.254-269
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• 2017

The work describes an assessment of the major air pollutants, $NO_2$, $SO_2$, CO, $O_3$, $NH_3$, coarse and fine particulate matter ($PM_{10}$, $PM_{2.5}$) in ambient air in and around a 3 million tonne Petroleum Refinery and the possible impacts on a pristine area marked by the presence of the world-famous Kajiranga National Park, a world heritage site and habitat for the most number of one-horned rhinos in the world. The Refinery is at an aerial distance of 20-25 km from the wildlife habitat. The assessment is based on regular monitoring at four stations around the Refinery and one station near the National Park. Heavy rains during June to August influence the pollutant concentrations while at other times of the year, large traffic volume adds to the pollutant concentrations that peak during November to March, the dry months of the year. Correlation analysis by scatter technique is utilised to obtain the enhancement ratios to predict the variations in the concentrations of the pollutants and their spatial distribution. Computation of air quality index (AQI) indicates that the coarse and the fine particulates in the ambient air could be a major hazard to wildlife in the area.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.3
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• pp.108-114
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• 2014

On a large scale of data center, heat generation rates from sever computers occupy almost the entire cooling load of the building, and it is gradually increasing. The efficiency of air distribution system in data centers can be affected by heat generation rates of server computers. In this study, the distributions of airflow and temperature in a data center have been investigated by CFD simulations under various conditions of heat generation rates for server computers. From the results, air around the cold aisle which has high temperature flows tremendously into the cold aisle according to the increase of heat generation rates for server computers and the air temperature in the cold aisle becomes higher. The SHI (supply heat index) and RHI (return temperature index) show almost similar values to the cases study because the air inflow rates to server computers increase with the heat generation rates of server computers.

• Preventive Nutrition and Food Science
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• v.20 no.2
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• pp.143-147
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• 2015

Systematic study of how different drying methods, namely hot-air drying, vacuum-drying, and freeze-drying, affect color, browning index, degree of rehydration, water solubility, and vitamin C content is critical for utilizing pine needle powders (PNP) as a novel ingredient in functional foods. Samples prepared by vacuum-drying showed a significantly higher $L^*$-value, whereas higher $a^*$- and $b^*$-values were detected in the hot-air dried samples (P<0.05). The browning index was significantly higher in samples prepared by vacuum-drying compared to samples prepared by freeze-drying (P<0.05). Freeze-dried PNP exhibited a significantly higher degree of rehydration than hot-air dried samples (P<0.05). Water solubilities of freeze-dried and hot-air dried samples were significantly higher than that of vacuum-dried sample (P<0.05). Vitamin C was less destroyed during freeze-drying compared to hot-air or vacuum-drying (P<0.05). Freeze-dried samples displayed a clear porous structure and appeared to have a bigger space, whereas hot-air dried samples showed lower porosity than vacuum and freeze-dried samples.

• Analytical Science and Technology
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• v.8 no.4
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• pp.807-814
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• 1995

Accurate measurements of ozone precursors are required to understand the process and extent of ozone formation in rural and urban areas. Nonmethane hydrocarbons (NMHCs) have been identified as important ozone precursors. Identification and quantification of NMHCs are difficult because of the large number present and the wide molecular weight range encountered in typical air samples. A major plan of the research team of the Climate and Air Quality Taiwan Station (CATs) was the measurement of atmospheric nonmethane hydrocarbons. An analytical method has been development for the analysis of the individual nonmethane hydrocarbons in ambient air at ppb (v) and subppb(v) levels. The whole ambient air samples were collected in canisters and analyzed by GC-FID with $Al_2O_3$/KCl PLOT column. Our targeted for quantitative analysis 43 compounds that may be substantial contributors to ozone formation. The retention indices and molar response factors of some commercially available $C_2{\sim}C_{10}$ hydrocarbons were determined and used to identify and quantify air samples. A quality assurance program was instituted to ensure that good measurements were made by participating in the International Nonmethane Hydrocarbon Intercomparison Experiments (NOMHICE).

• Corrosion Science and Technology
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• v.20 no.2
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• pp.94-104
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• 2021

Atmospheric corrosion severity associated with aircraft parking environment was studied using metallic specimens, and temperature and humidity sensors installed at each aircraft operating base. Data were analyzed after a year of exposure. Silver was used to measure chloride deposition by integrating X-ray photoelectron spectroscopy depth profiles. Carbon steel was utilized to determine the corrosion rate by measuring the weight loss. The time of wetness was determined using temperature and humidity sensor data. Analysis of variance followed by Tukey's "honestly significant difference" test indicated that atmospheric environment inside the shelter varied significantly from that of unsheltered parking environment. The corrosion rate of unsheltered area also varies with the roof. Hierarchical clustering analysis of the measured data was used to classify air bases into groups with similar atmospheric corrosion. Bases where aircraft park at a shelter can be grouped together regardless of geographical location. Unsheltered bases located inland can also be grouped together with sheltered bases as long as the aircraft are parked under the roof. Environmental severity index was estimated using collected data and validated using the measured corrosion rate.

• Journal of Preventive Medicine and Public Health
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• v.47 no.4
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• pp.230-235
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• 2014

Objectives: The aim of this study was to investigate whether the health status of Republic of Korea Air Force (ROKAF) soldiers changed after one year of military service. Methods: We selected 483 ROKAF soldiers from the 11 749 recruits who participated in the 2011 physical examination. The selected soldiers underwent another physical examination in 2012 for advancement to senior airman. Data from 2011 and 2012 were merged. To collect data on lifestyle, a questionnaire was sent to all included subjects via the military intranet e-mail service. Results: The percentage of recruits with an abnormal alanine transaminase level (normal range <40 IU/L) decreased from recruitment (13.7%) to the following year (2.7%). Moreover, the percentage of obese soldiers (body mass index ${\geq}25kg/m^2$) decreased from recruitment (20.5%) to the following year (10.4%). There was a significant change in mean duration of exercise carried out each day before ($0.8{\pm}1.3$ hours) and after ($1.0{\pm}0.7$ hours) joining the ROKAF service. Conclusions: These ROKAF soldiers were generally in good health before and after joining the armed service. After one year of military service, the health status of most soldiers improved, especially with respect to body mass index and alanine transaminase level.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.85-91
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• 2020

In order to calculate the Crop Water Stress Index (CWSI), it is necessary to collect weather data (air temperature, humidity, wind speed and solar radiation) and canopy temperature. However, it is not always available to have necessary data sets for CWSI calculation. Therefore, this study was aimed to develop an easy and simple CWSI equation (CWSI_EE) using only two data, air and canopy temperatures. Infrared sensors and weather sensors were installed on apple and peach trees and nearby a study area and every ten-minute data were collected from June to October in 2018 and 2019, respectively. A relationship between air-canopy temperature difference and CWSI was statistically analyzed and used to develop CWSI_EE using the three dimensional Gaussian model. The performance of CWSI_EE against original CWSI showed R² and NSE to 0.780 and 0.710 for apple trees and R² and NSE to 0.884 and 0.866 for peach trees. This study found that the level of crop water stress could be easily calculated using CWSI_EE with only air and canopy temperature data.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.8
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• pp.599-606
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• 2007

An experimental study was performed to measure a ice concentration of ice slurry flowing in a pipe in a real time. In the present paper, we suggested a measuring method by a refractive index and compared it to other methods by a freezing point and a density. To measure the refractive index of the solution, ice particles in the ice slurry should be completely removed and a hydro-cyclone was introduced instead of a mesh. The measuring method through the refractive index coincided with the density method using the real-time solution density within ${\pm}5%$ error range, having the error range less than the other two methods. In the other hand, the measuring method through the density has a good resolution, but the result using the initial density of the solution was different more than 10% error from that using the real-time density. And it has an error range 1.5 times greater than the method through the refractive index.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.144-154
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• 2021

Objectives: This study was intended to identify hazard contribution by region, media, and chemical by calculating a hazard-based index using pollutant release and transfer register (PRTR) data. Methods: PRTR data for the period 2011 to 2016 was analyzed to examine the regional trends in toxic releases in terms of quantity and to create a corresponding hazard-based index. For the hazard-based index, the Risk-Screening Environmental Indicators (RSEI) Model was used. Results: The results of the trend analysis show that total releases decreased slightly, but health hazard levels increased consistently. According to the outcome of regional contribution analysis of the hazard-based index, Chungcheongnam-do, Jeollabuk-do and Gyeonggi-do Provinces showed a high ratio in the index for air and water release pollutants, while Gyeongsangbuk-do and Gyeongsangnam-do Provinces showed a high ratio in the index of soil release and waste transfer pollutants. Also, as a result of the analysis of the top ranked substances in the hazard-based index, it was found that chromium, cobalt and its compounds, and ethylene oxide contributed greatly to air release substances, while chromium, benzene, and lead and its compounds contributed greatly to water release substances. Conclusion: These results showed considerable disparities between total release and health hazard levels, especially in the analysis of contribution by regions and by chemical substance. Therefore, the hazard-based index should be used both to support a more comprehensive and robust approach to screening of chemicals for environmental health policy and for management.