• Tuberculosis and Respiratory Diseases
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• v.61 no.1
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• pp.26-33
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• 2006

Background: Noninvasive positive pressure ventilation(NPPV) has been increasingly used over the past decade in the management of acute or chronic respiratory failure and weaning of mechanical ventilation. We performed this clinical study to evaluate the usefulness of NPPV in patients who developed acute respiratory failure or post-extubation respiratory failure. Methods: We analysed thirty four patients(sixteen males and eighteen females, mean ages 58 years) who applied NPPV(BIPAP S/T, Respironics co., USA) for respiratory failure or weaning difficulty at medical intensive care unit(MICU), emergency room and general ward of a tertiary hospital. We evaluated the underlying causes of respiratory failure, duration of treatment, the degree of adaptation, complication and predictive parameters of successful outcome. Results: The overall success rate of NPPV was seventy-one percent. The duration of NPPV applying time, baseline blood pressure, pulse rate, respiration rate, $PaO_2$, $PaCO_2$, $SaO_2$ were not different between success group and failure group. But, the baseline pH was higher in the success group. Predictors of success were higher baseline pH, patients with underlying disease of COPD, improvement of vital sign and arterial blood gas value after NPPV application. The success rate in patients with post-extubation respiratory failure was eighty percent. There were no serious complication on applying NPPV except minor complications such as facial skin erythema, abdominal distension & dry mouth. Conclusion: NPPV may be effective treatment in patients with acute respiratory failure or post-extubation respiratory failure in selected cases.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1523-1528
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• 1999

The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.304-313
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• 1979

The compositions of the polar lipids in the free and bound lipids from four varieties of experimentally cultivated potatoes were identified and quantified by thin layer- and gas-liquid chromatographies. The results were summarized as follows : 1. The glycolipids contained in the free and bound lipids were fractionated and identified as esterified sterol glycoside, monogalactosyl diglyceride, sterol glycoside, digalactosyl diglyceride, and trigalactosyl diglyceride, of which the highest content to the total lipid quantity were 5.8% of esterified sterol glycoside in the free lipid and 6.1% of trigalactosyl diglyceride in the bound lipid. The content of monogalactosyl diglyceride in the free and bound lipids was almost the same, whereas the content of esterified sterol glycoside was higher in the free lipid than in the bound lipid, and the contents of sterol glycoside, digalactosyl diglyceride, and trigalactosyl diglyceride were higher in the bound lipid than in the free lipid on the contrary. 2. The phospholipid contained in the free and bound lipids were fractionated and identified as phosphatidyl ethanolamine, phosphatidyl glyceride, phosphatidyl choline, and phosphatidyl inositol, but the phosphatidyl glyceride was not detected in the free lipid. The highest content in the total lipid quantity was 3.3 % of phosophatidyl choline in the case of the free lipid, while 14.9 % of the phosphatidyl ethanolamine contained in the bound lipid was the highest. All other constituents of phospholipid were contained in larger quantity in the bound lipid than in the free lipid. 3. The fatty acid composition of glycolipid in the free and bound lipids was also the same as that of the total free and bound lipids. The differences were that the content of palmitic acid was higher in the glycolipid of the free lipid than in the total free lipid and the content of linoleic acid was lower in the glycolipid.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.557-576
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• 2015

Groundwaters in granite, gneiss, and two-mica granite formations, including faults, in the Hoengseong area are examined to determine the relationship between their uranium and radon-222 contents and rock types. The chemical compositions of 38 groundwater samples and four surface water samples collected in the study area were analyzed. Sixteen of the samples showing high uranium and radon-222 contents were repeatedly analyzed. Surface radioactivities were measured at 30 points. The uranium and radon-222 concentrations in the groundwater samples were in the ranges of 0.02-49.3 μg/L and 20-906 Bq/L, respectively. Four samples for uranium and 35 samples for radon had concentrations exceeding the alternative maximum contaminant level of the US EPA. The chemical compositions of groundwaters indicated Ca(Na)-HCO₃ and Ca(Na)-NO₃(HCO₃+Cl) types. The pH values ranged from 5.71 to 8.66. High uranium and radon-222 contents in the groundwaters occurred mainly at the boundary between granite and gneiss, and in the granite area. The occurrence of uranium did not show any distinct relationship to that of radon-222. The radon-222, an inert gas, appeared to be dissolved in the groundwater of the aquifer after wide diffusion along rock fractures, having been derived from the decay of uranium in underground rocks. The results in this study indicate that groundwater of neutral or weakly alkaline pH, under oxidizing conditions and with a high bicarbonate content is favorable for the dissolution of uranium and uranium complexes such as uranyl or uranyl-carbonate.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.21-26
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• 1994

Lysimeter experiments were carried out to study the vertical distribution of inorganic nitrogen, the changes in pHs of soil and leachate and the fate of applied nitrogen with or without grass. The concentration of $NO_3-N$ of surface soil(0~20cm) at the rates of 0, 7, 14 and 21kg N/10a ranged from 4 to 13mg/kg, while those of subsurface soi1(20-40cm) were below 10mg/kg at 0, 7 and 14kg N/10a and subsequently increased to 83.8mg/kg at 35kg N/10a. The concentration of $NH_4{^+}-N$ was positively correlated with that of $NO_3-N$ for surface soil(>0.05). However, the concentration of $NH_4{^+}-N$ was negatively correlated with that of $NO_3-N$ for subsurface soil. A positive correlation was observed between $NO_3-N$ and extractable cations of soils. The pH of subsurface soil decreased with the $NO_3-N$ concentration and the N application rate, while that of leachate inereased with the N application rate. The pH differences between subsurface soil and leachate were 2.5 for bare soil and 3.1 for 35kg N/10a. Higher N application rate caused more soil N accumulation and the gas loss and resulted in a larger difference between N uptake by grass and the applied N.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.302-309
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• 2009

We fabricated a Si nano floating gate memory with Schottky barrier tunneling transistor structure. The device was consisted of Schottky barriers of Er-silicide at source/drain and Si nanoclusters in the gate stack formed by LPCVD-digital gas feeding method. Transistor operations due to the Schottky barrier tunneling were observed under small gate bias < 2V. The nonvolatile memory properties were investigated by measuring the threshold voltage shift along the gate bias voltage and time. We obtained the 10/50 mseconds for write/erase times and the memory window of $\sim5V$ under ${\pm}20\;V$ write/erase voltages. However, the memory window decreased to 0.4V after 104seconds, which was attributed to the Er-related defects in the tunneling oxide layer. Good write/erase endurance was maintained until $10^3$ write/erase times. However, the threshold voltages moved upward, and the memory window became small after more write/erase operations. Defects in the LPCVD control oxide were discussed for the endurance results. The experimental results point to the possibility of a Si nano floating gate memory with Schottky barrier tunneling transistor structure for Si nanoscale nonvolatile memory device.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.318-330
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• 2009

A high heat flux test facility using a graphite heating panel was constructed and is presently in operation at Korea Atomic Energy Research Institute, which is called KoHLT-1. Its major purpose is to carry out a thermal cycle test to verify the integrity of a HIP (hot isostatic pressing) bonded Be mockups which were fabricated for developing HIP joining technology to bond different metals, i.e., Be-to-CuCrZr and CuCrZr-to-SS316L, for the ITER (International Thermonuclear Experimental Reactor) first wall. The KoHLT-1 consists of a graphite heating panel, a box-type test chamber with water-cooling jackets, an electrical DC power supply, a water-cooling system, an evacuation system, an He gas system, and some diagnostics, which are equipped in an authorized laboratory with a special ventilation system for the Be treatment. The graphite heater is placed between two mockups, and the gap distance between the heater and the mockup is adjusted to $2{\sim}3\;mm$. We designed and fabricated several graphite heating panels to have various heating areas depending on the tested mockups, and to have the electrical resistances of $0.2{\sim}0.5$ ohms during high temperature operation. The heater is connected to an electrical DC power supply of 100 V/400 A. The heat flux is easily controlled by the pre-programmed control system which consists of a personal computer and a multi function module. The heat fluxes on the two mockups are deduced from the flow rate and the coolant inlet/out temperatures by a calorimetric method. We have carried out the thermal cycle tests of various Be mockups, and the reliability of the KoHLT-1 for long time operation at a high heat flux was verified, and its broad applicability is promising.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.105-118
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• 2006

Isolation and Identification of fatty acid and volatile compounds in tuna fish oil were successfully carried out using supercritical carbon dioxide. Samples of the oil were extracted in a 56 ml semi-batch stainless steel vessel under conditions which ranged from 80 to 200 bar and 40 to $60^{\circ}C$ with carbon dioxide flows from 10 ml/min. Volatiles in the oil extracted from the samples with supercritical carbon dioxide were analyzed by gas chromatography, mass detector with canister system. The extracts were contained with various fatty acids, 57.0% of unsaturated fatty acids such as docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA), and 43.0% of saturated fatty acids. The aroma compounds in the oil showed over 129 peaks, of which 100 compounds were identified. Volatile components included 2,4-hepatadienal(fishy), dimethyldisulfide (unpleasant), dimethyltrisulfide (unpleasant) and 2-nonenal(fatty). The isolation efficiency of the volatile compounds from the samples was 99.4% at $50^{\circ}C$ and 200 bar.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1002-1008
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• 2000

The purpose of this study was to provide the fundamental information for establishing the database needed to estimate total intakes of trans fatty acids in Korea. The amounts of trans fatty acids contained in 164 samples including 25 samples of margarines, 21 samples of shortenings, 19 samples of vegetable salad and cooking oils, 53 samples of confectionery products, 18 samples of bakery products, 19 samples of dairy products, and 9 samples of animal fats and meats were analyzed by capillary gas liquid chromatography. The average amounts of trans fatty acids in those foods were calculated and expressed as gram per one serving. Then, the average daily intakes of trans fatty acids per capita were estimated using the analyzed amounts of trans fatty acids and the amount of yearly production for those foods. The amounts of trans fatty acids per 100 g of lipids were $2.11{\sim}33.83%$ (14.66% on average) in margarines, $1.47{\sim}44.48%$ (14.21% on average) in shortenings, $0.18{\sim}3.82$ (1.54% on average) in vegetable salad and cooking oils, $0{\sim}45.81%$ (10.92% on average) in confectionery products, $0{\sim}18.32%$ (7.87% on average) in bakery products, $0.90{\sim}4.54%$ (2.27% on average) in dairy products, and $0.61{\sim}6.07%$ (2.24% on average) in animal fats and meats. Major isomers of trans fatty acid in the sample foods were $C_{18:1}$ and $C_{18:2}$. As a result, the korean average daily intake of trans fatty acids in korea was estimated to be 2.3 g per capita. The amounts of trans fatty acids consumed from each selected food were as follows: 0.35 g from margarines, 0.57 g from shortenings, 0.11 g from vegetable salad and cooking oils, 0.65 g from confectionery products, 0.07 g from bakery products, 0.14 g from dairy products and 0.21 g from animal fats and meats.