• Journal of the Korea Concrete Institute
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• v.26 no.5
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• pp.651-660
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• 2014

Structural members using ultra high strength concrete which usually used with steel fiber is designed with guidelines based on several investigation of SF-RPC(steel fiber reinforced reactive powder concrete). However, there are not clear design method yet. Especially, SF-RPC member should be casted with steam(90 degree delicious) and members with SF-RPC usually used with precast members. Although the most important design parameter is development method between SF-RPC and steel reinforcement(rebar), there are no clear design method in the SF-RPC member design guidelines. There are many controversial problems on safety and economy. Therefore, in order to make design more optimum safe design, in this study, we investigated bond stress between steel rebar and SF-RPC according to test. Test results were compared with previously suggested analysis method. Test was carried out with direct pull out test using variables of compressive strength of concrete, concrete cover and inclusion ratio of steel fiber. According to test results, bond stress between steel rebar and SF-RPC increased with increase of compressive strength of concrete and concrete cover. Increasing rate of bond stress were decrease with increase of compressive strength of SF-RPC and concrete cover significantly. 1% volume fraction inclusion of steel fiber increase the bond stress between steel rebar and SF-RPC with two times but 2% volume fraction cannot affect the bond stress significantly. There are no exact or empirical equations for evaluation of SF-RPC bond stress. In order to make safe bond design of SF-RPC precast members, previously suggested analysis method for bond stress by Tepfers were evaluated. This method have shown good agreement with test results, especially for steel fiber reinforced RPC.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.774-783
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• 2004

The S wave velocity and Q$s^{-1}$ structure of the uppermost part of the soil in Nakdong Delta area have been obtained to determine the characteristics of the forementioned soil. The phase and attenuation coefficients of multichannel seismic records were inverted to obtain the S wave velocity and Q$s^{-1}$ structure of the soil. The inversion results have been compared with the borehole measurements of the area. The seismic signal of the nearest geophone from a seismic source was used as the source signal to obtain the attenuation coefficients. Amplitude ratios of the signal at each geophone to the source signal wave plotted as a function of distance for the frequency range between 10 Hz and 45 Hz. The slope of a linear regression line which fits amplitude ratio-distance relationship best for a given frequency was used as the attenuation coefficients for the frequency. The dispersion curve of Rayleigh waves and the attenuation coefficients were inverted to obtain the S-wave velocity and Q$s^{-1}$, respectively, in the uppermost 8 meter of soil layer. The borehole measurements of the area show that are two distinct layers; the upper 4 meter of silty-sand and the lower 4 meter of silty-clay. The inversion results indicate that the shear wave velocity of the upper layer is 80 m/sec and 40m/sec in the lower silty-clay layer. The spacial resolution of the shear wave velocity structure is very good down to a depth of 8 meter. The Q$s^{-1}$ in the upper silty-sand layer is 0.02 and increase to 0.03 in the lower silty-sand layer. The spacial resolution of quality factor is relatively good down to a depth of 5 meter, but very poor below the depth. In this study, the S-wave velocity is higher in the silty-clay and the Q$s^{-1}$ is smaller silty-sand than in the silty-clay. However, much more data should be analyzed and accumulated before making any generalization on the shear wave velocity and Q$s^{-1}$ of the sediments.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.395-404
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• 2002

Background : Surfactant protein A (SP-A) is important for regulating surfactant secretion, synthesis and recycling. However, It's regulation in vivo is unclear. SP-A has important roles in regulating surfactant metabolism as well as determining its physical properties. Glucocorticoid accelerates the morphologic differentiation of epithelial cells into type II cells and increase the rate of phosphatidylcholine synthesis. Methods : The authors investigated the effects of glucocorticoid on the accumulation of mRNA encoding SP-A and SP-A protein content. Adult rats were given various doses of subcutaneous dexamethasone and sacrificed after 24 hours and one week. SP-A mRNA was measured using a filter hybridization method. The lung SP-A protein content was determined using a double sandwich ELISA assay with polyclonal antiserum raised in rabbits against purified rat SP-A. Results : 1) The accumulation of SP-A mRNA in the dexamethasone treated group 24 hours after 0.2 mg/kg dexamethasone treatment was increased 38.8% compared to the control group. 2) The accumulation of SP-A mRNA in the dexamethasone treated group 1 week after 2 mg/kg dexamethasone treatment was 49.7% higher than the control group(P<0.01). 3) The total lung SP-A level was not altered after 24 hours by the 0.2mg/kg treatment. The total lung SP-A content one week after 2mg/kg dexamethasone administration was 373.7% higher than the control group(P<0.005). Conclusion : Dexamethasone treatment results in an increase in the SP-A mRNA and SP-A protein levels, suggesting that the pretranslational events in vivo may in part contribute to this process.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.376-384
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• 2002

Background : The mortality from acute respiratory distress syndrome(ARDS) in the late stage, which is characterized by progressive pulmonary fibroproliferation, is ${\geq}80%$. Although previous prospective trials failed to show a survival benefit of steroid therapy in early ARDS, recently, a few of reports have described the survival benefit of the long-term use of steroid in patients with late ARDS. In this study, we analyzed the effect of steroid therapy on patients with late ARDS retrospectively in a single. Medral intensive care unit (MICU). Methods : Over a 3-year period, the medical records of 48 ARDS patients who had been on mechanical ventilation more than 8 days were reviewed. 14 patients were treated by the long-term use of methylprednisolone and another 34 patients served as a control. Both groups were comparable regarding clinical and physiologic data lung injury score(LIS), multiple organ failure score, APACHE III and SAPS II score. Because steroid was instituted after 8 days of advanced mechanical ventilatory support in average, we arbitrarily defined the $8^{th}$ day of ARDS as first day of the study. Results : Initially, the groups had similar PF($PaO_2/FiO_2$) ratio, LIS, APACHE III and SAPS II score. By 7th day after the start of steroid therapy, there were significant improvements in PF ratio, LIS, APACHE III and SAPS II score. The mortality in the steroid treated group was significantly lower(42.9% vs 73.5%, p<0.05). Conclusion : Although the data of this study was retrospective and was not randomized, in order to improve the patient's outcomes, steroid therapy should be considered in late ARDS patients. However, prospective trials are needed to define the indication and the effect of steroid therapy in late ARDS.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.191-201
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• 1987

Seasoned sardine meat was prepared to extend the use of sardine for human consumption, and processing conditions and storage stability of frozen seasoned sardine meat were studied during storage at $-20^{\circ}C$. The fish was beheaded, gutted and cleaned in a washing tank. The washed fish was then put through a belt-drum type meat separator which separates the flesh iron the bone and skin. Mechanically deboned fish meat was mixed with $20.6\%$ emulsion curd, $0.5\%$ table salt, $2.0\%$ sugar, $0.4\%$ sodium bicarbonate, $0.2\%$ polyphosphate, $0.1\%$ monosodium glutamate, $0.3\%$ onion powder, $0.1\%$ garlic powder, $0.1\%$ ginger powder, $3.0\%$ soybean protein and $0.1\%$. In sodium erythorbate. This seasoned sardine meat was frozen with contact freezer, packed in a carton box and then stored at $-20^{\circ}C$. The pH, volatile basic nitrogen, viable cell counts, peroxide value, carbonyl value, thiobarbituric acid value, taste compounds, fatty acid composition, salt extractable nitrogen, drip, texture, and color values of the products were determined during frozen storage. The results showed that lipid content in products could be controlled by using emulsion curd, and flavor and texture could be improved by adding spices and soybean protein, and lipid oxidation could be retarded by $0.1\%$ sodium erythorbate. Judging from the results of chemical experiments and sensory evaluation, the products can be preserved in a good quality for 120 days during frozen storage.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1065-1074
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• 2002

Purpose : The purpose of this study is to analyze the epidemiologic characteristics of sudden unexpected death in infancy and to evaluate the importance of postmortem autopsy. Methods : We reviewed, retrospectively, medical records of 34 infants admitted to Kangnam General Hospital from January 1987 to December 2001 because of sudden unexpected death. We investigated the cause of death through medical history, death scene examination, autopsy findings, acylcarnitine and organic acid analysis. Results : Among the total 34 infants, 18 were male(52.9%) and 16 were female(47.1%). Thirty infants(88%) were below the six months of age. Winter was the most affected season(38.2%). Eighteen infants(52.9%) died between 6 and 12AM. The prone sleeping position was observed more frequently than the supine position at death; nine cases in the prone position, six cases in the supine position. The cause of death of 23 cases could not be found by only history and death scene examination. Autopsy was done in 13 cases. Seven cases of them were thought to be SIDS. In six cases, we explained the cause of death with autosy findings. They were an endocardial fibroelastosis, a nesidioblastosis, a subdural hematoma, a bronchopneumonia and two fatty changes of liver. Metabolic screening tests performed in three cases to rule out metabolic disorder since 2000 were all normal. Conclusion : We concluded that autopsy and metabolic screening test should be performed to find out the cause of death in sudden unexpected death in infancy.

• Korean journal of food and cookery science
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• v.15 no.3
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• pp.203-209
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• 1999

The effect of several hydrocolloids on the rheological behavior of wheat flour was investigated. The influence of the selected hydrocolloids (alginate, carrageenan, CMC, guar, locustbean and xanthan) on wheat flour was tested by using two different techniques; amylograph and texture analyzer. In order to have a general overview of their effects hydrocolloids were chosen from different sources implying a broad diversity of chemical structures. The hydrocolloid addition decreased the brightness(L) but increased yellowness(b). The interaction between hydrocolloid and flour produces a slight modification of the amylogram parameters, being the most clearly affected parameter breakdown, which is increased by carrageenan, guar and xanthan. Hardness and cutting force were augmented by hydrocolloid addition, while springeness was decreased except guar and locustbean. In summary, when looking for the improvement of the noodle texture, guar, locustbean are the best candidate additives due to their effects on pasting and texture properties. These hydrocolloids increase the hardness, cutting force, gumness, chew-ness, so were thought to increase the eating quality. So, each tested hydrocolloid affected in a different way the rheological properties of wheat flour, the results obtained are important for the appropriate use of these hydrocolloid as ingredients in the noodle making process.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.33-40
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• 2006

Many soil amendments have been used nowadays to improve physical and chmical condition of turf soil, which might ultimately optimize turfgrass growth in golf courses. This study was carried out to Investigate the effects of new organic soil amendment containing pig excreta 50% and sawdust 50% on growth of zoysiagrass (Zoysia japonica L.) and kentucky bluegrass (Poa pratensis L.) in greenhouse. Three applicable treatments with soil mixtures of 10, 20, and 30% (v/v) animal organic soil amendment (AOSA) with sand, were tested for chemical property, physical property, visual quality and root length of zoysiagrass and Kentucky bluegrass. As results, application of $10{\sim}30%$ AOSA mixtures were proper to grow turfgrass in soil nutrition. Especially, the treatment with 20% AOSA mixtures showed 0.7% in organic matter, which meets to green standard of USGA. Also, 30% AOSA mixtures was 1.1% in organic matter, which might be desirable for zoysiagrass-planted golf courses in Korea. It was turned out that addition of AOSA decreased the hydraulic conductivity in soil physical property Because the sand possess high hydraulic conductivity, it is recommended to combine $10{\sim}30%$ AOSA with sand in order to sustain soil balance. The treatment with $10{\sim}30%$ AOSA noticeably increased visual quality of both zoysiagras and Kentucky bluegrass during 90 days. However, treatments with either 20% or 30% AOSA were effective to develop root length of zoysiagrass but treatments with 20% AOSA were more effective than that of 30% AOSA mixtures to promote root length of Kentucky bluegrass at 60 days. In conclusion, considering all vital factors such as visible quality, root growth, organic matter content, and economical efficiency, was taken, it is recommended that a $20{\sim}30%$ mixture of AOSA with sand is good for the growth of zoysiagrass and 20% mixture for Kentucky bluegrass.

• Geophysics and Geophysical Exploration
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• v.11 no.1
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• pp.52-59
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• 2008

We have developed a new deep-towed marine DC resistivity survey system. It was designed to detect the top boundary of the methane hydrate zone, which is not imaged well by seismic reflection surveys. Our system, with a transmitter and a 160-m-long tail with eight source electrodes and a receiver dipole, is towed from a research vessel near the seafloor. Numerical calculations show that our marine DC resistivity survey system can effectively image the top surface of the methane hydrate layer. A survey was carried out off Joetsu, in the Japan Sea, where outcrops of methane hydrate are observed. We successfully obtained DC resistivity data along a profile ${\sim}3.5\;km$ long, and detected relatively high apparent resistivity values. Particularly in areas with methane hydrate exposure, anomalously high apparent resistivity was observed, and we interpret these high apparent resistivities to be due to the methane hydrate zone below the seafloor. Marine DC resistivity surveys will be a new tool to image sub-seafloor structures within methane hydrate zones.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.33-43
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• 2020

CO₂ geological storage is currently considered as the most stable and effective technology for greenhouse gas reduction. The saline formations for CO₂ geological storage are generally located at a depth of more than 800 m where CO₂ can be stored in a supercritical state, and an extensive impermeable cap rock that prevents CO₂ leakage to the surface should be distributed above the saline formations. Trough analysis of seismic and well data, we identified the basalt flow structure for potential CO₂ storage where saline formation is overlain by basalt cap rock around PZ-1 exploration well in the Southern Continental Shelf of Korea. To evaluate CO₂ storage capacity of the saline formation, total porosity and CO₂ density are calculated based on well logging data of PZ-1 well. We constructed a 3D geological grid model with a certain size in the x, y and z axis directions for volume estimates of the saline formation, and performed a property modeling to assign total porosity to the geological grid. The estimated average CO₂ geological storage capacity evaluated by the U.S. DOE method for the saline formation covered by the basalt cap rock is 84.17 Mt of CO₂(ranges from 42.07 to 143.79 Mt of CO₂).