• International Journal of Highway Engineering
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• v.12 no.2
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• pp.107-113
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• 2010

In this study, the relative effects of low-chloride deicier(LCD) and two other deicing agents on the scaling of concrete were conducted in a series of tests at laboratory accordance with the ASTM C 672. The solutions concentration of deicers tested included 1, 4, 10%. Tap water was used as control. The amount of scaling was evaluated gravimetrically. As test result of deicer solution types, when applied to 4% solutions, surface scaling of concrete after 56 freeze-thaw cycles was produced significantly as about 9 times on LCD solution, as about 18 times on $CaCl_2$ solution, and as about 33 times on NaCl solution comparing with tap water. As test result of deicer solution concentrations, relatively low concentrations (of the 4% by weight) of deicer were produced more surface scaling than higher concentrations (of the 10% by weight) or lower concentrations (of the 1% by weight) of deicer. It show that the damaging concentration is of the order of 3~4% for previous research result. It appears that the mechanism of surface scaling is primarily physical rather than chemical. Also, the effect of chloride deicier types, freeze-thaw cycling, and air contents on the performance of concrete was experimentally investigated. The results show that the concrete specimens subjected to freeze-thaw cycling scaled more severely in exposure to deicing salt than those in non-exposure to deicing salt, weight losses of the specimens tested in exposure to deicing salt were twice as much as those tested in non-exposure to deicing salt. Relative dynamic modulus of elasticity of concrete specimens decreased more quickly in exposure to deicing salt than in non-exposure to deicing salt. Also, relative dynamic modulus of elasticity of concrete specimens in exposure to sodium chloride deicing salt was decreased more quickly comparing with exposure to LCD salt. It is also shown that the chloride contents according to concrete specimen depths was more largely in exposure to LCD salt. When concrete specimen is exposed to chloride deicing salts and freeze-thaw cycling, performance degradation in the entrained air concrete(AE concrete) retarded more considerably comparing with non-entrained air concrete(Non-AE concrete).

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1200-1206
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• 2003

Purpose : This study was conducted for the use of nasal continuous positive airway pressure (CPAP), by comparing the early use of non-invasive nasal CPAP with low intermittent mandatory ventilation(low IMV) and endotracheal CPAP in weaning a mechanical ventilator from infants with moderate respiratory distress syndrome(RDS). Methods : Thirty infants in the study group, with moderate RDS from November 2001 to June 2002, were administered surfactants and treated with the mechanical ventilator, and applied the nasal CPAP in weaning. Thirty infants of the control group, from January 1999 to September 2001, were applied low IMV and endoctracheal CPAP in weaning. Results : There were no significant differences in the characteristics, the severity of clinical symptoms, the initial laboratory findings and settings of the mechanical ventilator. After weaning, the study group showed no significant changes in $PaCO_2$. However, the control group showed a slight $CO_2$ retension after one and 12 hours. Twenty eight infants(93.3%) of the study group and 24 infants(80%) of the control group were successfully extubated. The primary cause of failure was apnea. There were no significant differences in the duration of weaning and the mechanical ventilator treatment between the groups. Complications in weaning were related to the fixation of nasal CPAP and the mechanical problems caused by endotracheal tube. Conclusion : Aggressive weaning is possible for moderate RDS, in which the nasal CPAP was used without the low IMV and the endotracheal CPAP process. It had no difficulties. In conclusion, the nasal CPAP is an adequate weaning method for moderate RDS.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.150-154
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• 1983

Mushroom, Lentinus edodes which had been dried at $50^{\circ}C$ for 20 hours were extracted with small amount of ethanol, methanol, chloroform and petroleum ether, respectively. The extracts were then dissolved in edible soybean oil, and the resulting substrates and a portion of the soybean oil (control) were placed in an incubator $(37.0{\pm}1.0^{\circ}C)$ for eight weeks. Peroxide values and TBA values of control and the substrates were determined regularly during the storage period. The results of the present study were as follows: 1. The moisture contents of the mushroom which was 84.88% on wet basis at the time of harvest were reduced to 15.12% after drying. 2. Extracts obtained from alcohols were effective in retarding the POV development. 3. There was not much difference among the TBA values after 14 days, but significant difference of the TBA values in control and the substrates extracts were observed in longer storage period TBA values of substrate containing ethanol and methanol in the later stage period were smaller than that of the substrates containing petroleum ether and chloroform. 4. In view of the POV and TBA value development, ethanol and methanol were more effective solvents for the extraction of antioxidant compounds in the dried mushroom than chloroform and petroleum ether.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.503-513
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• 1997

This study was undertaken to investigate the effect of oxygen tension on the activity and function of the cells derived from human periodontal ligament by measuring cell activity, total protein synthesis, collagen synthesis, $IL-1{\beta},\;IL-6,\;TNF-{\alpha}$ Human periodontal ligament fibroblasts were collected from premolars extracted for orthodontic treatment and incubated in the environment of $37^{\circ}C,\;5\%\;CO_2,\100\%$ humidity. After the fifth to sixth passage they were used for the experiment. Gaspack system to which $0.2{\mu}m$ Millipore filter was attached was connected to mixed-gas tanks. The mixed gases were composed of $10\%\;O_2,\;5\%\;CO_2,\;85\%\;N_2$ in hyoxic group or $90\%\;O_2,\;5\%\;CO_2,\;5\%\;N_2$ in hyperoxic group and $5\%\;CO_2,\;95\%$ air for control. After incubation in $37^{\circ}C$ for 2, 4, 6 days, cell activity was determined by tetrazolium(MTT) assay and total protein synthesis was assayed using sulforhodamine B(SRB). And measurement of 4-hydroxyproline was performed to assess collagen synthesis md $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ were measured by enzymeimmunoassay. The results were as follows. 1. The cell activity and total protein synthesis in hypoxic group were a little higher than or almost the same with those in control group. 2. In hyperoxic group, the cell activity was lower than that in control group and total protein synthesis was decreased. 3. Collagen synthesis was significantly decreased initially in both hypoxic and hyperoxic group and increased nearly to the level of control group as the duration of cell incubation was longer 4. As a result of enzymeimmunoassay, the amount of cytokines was $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ in order. 5. $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ were increased more rapidly in both hypoxic and hyperoxic group than in control group as the duration of cell incubation was longer. 6. There were more $IL-6\;and\;TNF-{\alpha}$ in hyperoxic group than in control group after 6 days, and there were more $IL-6\;and\;TNF-{\alpha}$ after 6 days than after 2 or 4 days in hyperoxic group. These results suggested that oxygen tension might modulate the production of extracellular matrix and cytokines in the cells derived from human periodontal ligament.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.207-220
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• 2012

There are around 7,500 manure tanks to treat the manures from pigs in Korea. In the tank, there are too much sediments deposited on the base and wall, which causes low efficiency of stock capacity and manure fermentation. In order to minimize sediments and to ferment manure effectively, we developed a 2-fluid jet mixer for mixing sediments in liquid livestock manure tank. For developing the prototype, we tested a factorial experimental system with various nozzles, and simulated CFD models with two kinds of nozzle arrangement. From the results of factorial experiment and CFD simulation, we concluded the dia. ratio of primary : secondary nozzle should be 1:2 and the nozzles should be arranged at the same distances toward to the circumferential direction. With this results, we manufactured a 2-fluid jet mixer which is consists of four 2-phase nozzles, centrifugal slurry pump and root's type air blower. And, we carried out the performance test of the prototype in the round shaped liquid manure tank in the farm. The performance test results showed that the uniformity of TS (Total Solid) and VS (Volatile Solid) was raised from 21.3 g/L, 13.3 g/L In steady state to TS and VS to 23.0 g/L, 14.1 g/L in the mixing operation. Therefore, we could conclude that the prototype of 2-fluid mixer could make the solid material which could be sediments in the tank not to be deposited in the tank and to be contacted to air bubbles which could enhance the efficiency of the fermentation of livestock manure.

• Archives of design research
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• v.18 no.4 s.62
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• pp.25-34
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• 2005

The purpose of the present study is to investigate the characteristics of the current Victorian-style interior by reviewing the basic Victorian-style house in the past. this research was analyzed various prior studies and literatures, and found the following results: First, the Victorian-style house and interior space showed various historical trends and adopted every style from Gothic to rococo, and sometimes more than one style influenced a single place. Its formality was applied depending on the function and standard of each room. Second, the interior had many decorative things with free, irregular or other patterns, influenced by Romanticism and Naturalism. The several environmental factors such as air pollution and hygienic matter were also related with its trend. the dramatic changes in the kitchen and sanitary facilities were appeared based on the technical development, and affluent design styles were also used. All these reflected the characteristics of the Victorian age. In conclusion, the characteristics of Victorian-style were influenced by many factors including: (a) the trend of Romanticism and Naturalism, (b) consideration of family convenience based on the technical development, (c) the Socio-Environmental factors like air pollution and the social norm, and (d) reflection of the individual value in accordance with frequent contacts with foreign cultures. In this respect, it is necessary to reevaluate the Victorian-style after paying due regard to such factors.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.83-88
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• 2016

In this study, previously reported surplus solar energy-related study result and current status of fan coil unit (FCU) for cooling and heating installed in the current sites were briefly examined and then a method to determine the number of FCUs required to recover surplus solar energy was schematically proposed to provide basic data for researchers and technical engineers in this field. The maximum, mean, and minimum outside temperatures during the experiment period were about $28.2^{\circ}C$, $4.4^{\circ}C$, and $-11.5^{\circ}C$, respectively. The horizontal surface solar radiation level outside the greenhouse was in a range of $0.8-20.5MJ{\cdot}m^{-2}$ and mean and total solar radiation were $10.8MJ{\cdot}m^{-2}$ and $1,187.5MJ{\cdot}m^{-2}$. The mean temperature and relative humidity in the greenhouse during the daytime were in a range of 18.8-45.5 and 53.5-77.5%. The total surplus solar energy recovered from the greenhouse during the experiment period was approximately 6,613.4MJ, which could supplement about 6.7% of the total heating energy 98,600.2 MJ. In addition, the number of FCUs installed for heating varies case to case, although similar FCUs are used. Thus, it is necessary to study the installation height, orientation and installation distance as well as the appropriate number of FCUs from the efficient and economical viewpoints. The required numbers of FCUs for surplus solar energy recovery were 8.4-10.9units and 6.1-8.0units based on air mass and circular flow rate that passed through the FCUs. Considering calculation methods and the risks such as efficiency and use environments of FCUs, it was found that about nine units (one unit per $24m^3$ approximately) needed to be installed. The required number of FCUs for surplus solar energy recovery was around one unit per $24m^3$ approximately.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.247-257
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• 2014

Assessment for operator's dermal and inhalation exposure to acetamiprid during cultivation of water melon in greenhouse was carried out. For dermal exposure measurement, whole body dosimetry (WBD) was performed as the first trial in Korea. WBD consists of cotton/polyester outer clothes and cotton inner clothes. Hand exposure was measured by washing of nitrile gloves and hands while head exposure was monitored by face/neck wipe technique. Inhalation exposure was monitored with personal air sampling pumps and IOM sampler (glass fiber filter). Analytical limit of quantitation was 2.5 ng/mL. Good reproducibility (C.V < 8.7%), linearity ($R^2$ > 0.99) and recovery (70~119%) were obtained. Field recovery of acetamiprid was 77~95%. During mixing/loading, hand exposure of acetamiprid was about 10 times ($229.7{\mu}g$) more than that of application case ($20.9{\mu}g$). During application, total dermal exposure was $1207.4{\mu}g$. Exposure of lower legs was $1132.1{\mu}g$, which is 93.8% of the total dermal exposure. Inhalation exposure during mixing/loading and application was not detected. Margin of safety (MOS) was calculated for risk assessment using male Korean average body weight (70 kg) and acceptable operator exposure level ($124{\mu}g/kg/day$) to give 140, suggesting that health risk of operator during treatment of acetamiprid for water melon in greenhouse could be safe.

• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.89-95
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• 2009

Purpose: The purpose is to evaluate efficiency of the CT simulator QA phantom manufactured for daily QA. Materials and Methods: We made holes ($1{\times}100{\times}1\;mm$) to verify accuracy between image and real measurement in polystyrene phantom and made 1 mm holes to verify table movement accuracy at superior and inferior 100 mm to the center of the phantom and inserted radiopacity material. To evaluate laser alignment, we made cross mark on the right and left side at phantom and to evaluate CT number accuracy we made 3 cylindrical holes and inserted equivalence material of bone, water, air in them. After CT scanning the phantom, We evaluated accuracy between image and real measurement, accuracy of table movement, laser, and CT number using exposed image. Results: It was measured that the accuracy between image and real measurement was ${\pm}0.3\;mm$, table movement accuracy was ${\pm}0.3\;mm$, laser accuracy was ${\pm}0.5\;mm$ from 7th January to 7th March in 2008 as within the reference point ${\pm}1\;mm$. In the CT number accuracy of bone was ${\pm}10\;HU$, air was ${\pm}5\;HU$, water was ${\pm}5\;HU$ as within the reference point is ${\pm}10\;HU$. Conclusion: We was able to perform CT simulator QA and laser equipment QA more conveniently and fast using manufactured phantom at the same time. We will be able to make more accurate treatment plan that added to QA procedures using images at previous daily QA.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.556-560
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• 1999

Background: The cause of spontaneous pneumothorax is not yet but it is certain that intrathoracic air comes from ruptured bulla. Video-assisted thoracoscopic surgery(VATS) or open thoracotomy is recommended for thoracic incision in recurrent pneumothorax. However, recurrent rate after bullectomy with the VATS is very high compared to mini-thoracotomy, 3% to 20% and below 2%, respectively. Material and Method: This retrospective analysis was performed on 16 re-operated cases among 446 surgically treated pneumothorax of the 737 cases of spontaneous pneumothorax diagnosed at Yongdong Severance Hospital from Nov. 1992 to June 1997. Result: Among the 446 surgically-treated patients in 737 case of spontaneous pneumothorax, 16 patients underwent re-operation, showing a 3.5% re-operation rate. Male-to-female ratio was 15 to 1 and mean age at initial attack was 20.2 years(ranging from 15 to 50). Mean hospital stay was 6.34 days(ranging from 2 to 20 days) and mean chest tube indwelling period was 4.2 days(ranging from 1-10 days). Median follow-up was 46 months(range 10-66 months). Three different surgical methods were applied : video-assisted thoracoscopic surgery(VAST) in 281 cases, of whom 2 underwent local anesthesia; subaxillary mini-thoracotomy in 159 cases and limited lateral thoracotomy in the remaining 6 cases. Three different re-operative surgical methods were applied ; video-assisted thoracoscopic surgery (VAST) in 6 cases, subaxillary mini-thoracotomy in 9 cases, and limited lateral thoracotomy in the remaining 1 case. The underlying etiological factors of the recurrent pneumothorax after bullectomy were o erlooking type(9) and new growing type(7). Mean recurrent period from previous operation was 1 month for overlooking type and 18 months for new growing type. Conclusion: The underlying etiological factors of recurrent pneumothorax lead to re-operation were new-growing and over-looking type. We need additional treatments besides resecting blebs of prevent the recurrence rate and more gentle handling with forceps due to less damage to the pleura.