• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.158-164
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• 1981

Leaching of lead from glazed potteries was studied under various conditions. The amount of lead was determined by atomic absorption spectrophotometry. Lead content was tended to increase with lowering PH of the solution below pH 4, but it was not detected at above pH 6 during the storage period of six weeks. More lead was leached out from the glazed potteries with red color than those of black color at the same pH. No lead was detected when the medicine-boiling pots were boiled with water or $4\%$ acetic acid solution for six hours. A significant accumulation of lead, however, was shown in Kimchi and mixed solutions of organic acids when they stored in the glazed potteries more than three weeks, although they appeared lead-free by the Korean Industrial Standard Test Method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.453-458
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• 1986

The present study was directed to investigate the antioxidative effects of onion and mustard powder extracts on fish oil. The oxidative changes of sardine oil with and without onion and mustard powder extract were estimated by measuring peroxide value (POV), thiobarbituric acid (TBA) value, weighing method, acid value (AV) and fatty acid composition, periodically. The results obtained are summarized as follows ; From view point of POV, fat soluble fraction of onion and mustard powder showed much inhibitory effect on the oxidation of sardine oil, marked induction period to be prolonged about 18 and 20 days, respectively. But the POV in fat soluble fraction of mustard powder increased remarkably in the early stage of storage, so it did not show inhibitory effect on the oxidation of sardine oil. In the TBA value of sardine oil during storage, the water soluble fraction of onion and mustard powder were more slowly increased than other fractions. The weighing change of sardine oil, contained in the water soluble fraction of mustard powder, was slower than other fractions, marking $0.5\%$ of weight gain during 30 day storage. On the other hand water and $80\%$ ethanol soluble fractions of onion were marked $2.3\%\;and\;5.8\%$ of weight gain during 30 day storage. In the oxidative degradation of docosahexaenoic acid, water soluble fractions of mustard powder and onion extracts showed the strongest inhiditory effect.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.14-20
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• 2008

In this numerical study, the leakage safety of the LNG tank in which is constructed by membrane inner tank-plywood-polyurethane form-plywood-prestressed concrete structures has been presented for four leakage analysis models. The LNG leak criterion of the tank wall with a storage capacity of $200,000\;m^3$ is analyzed based on the thermal resistance technique. This means that if the cryogenic temperature of a leaked LNG is detected at the outer side of the PC wall, it may be leaked through the wall thickness of the tank. The calculated results based on the thermal resistance method between two walls show that the plywood, PUF, and another plywood walls may block the leakage of the leaked LNG even though the strength of these walls is already collapsed by a leaked LNG pressure. But, the leaked LNG may pass the thickness of the prestressed concrete wall for a period of elapsed time even though the PC outer tank supports the leaked LNG pressure. Thus, the PC outer tank may extend the leakage time of a leaked LNG.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.25-28
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• 1962

The colorimetric estimation, by dithiol method, of the solubility of tin dissolved from the container the tin plate in some canned marine foods has been made on 200 cans of sample on the market. Some of them contained more than 150 ppm of Sn concentration were as follows; (1) ca. 50% of squid can, (2)ca. 30% of mackerel can, (3) ca. of saury can, (4) naught of crab, whale, clam(Japanese hard clams), fish meat ball, and Turbo cornutus one. (1) It had the tendency of increasing Sn concentration according to lowering or arising the value of pH. (2) No significant difference in Sn concentration was caused by the variation of the sort of tinning as H-D or E-T. (3) The longer the period of the storage the higher Sn concentration was found, and the concentration more than 150 ppm of Sn was generally found among the cans stored more than twelve months. (4) The concentration of Sn in the liquid was higher than in solid portion, and most of dissolved Sn was distributed in the liquid portion.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1047-1060
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• 2003

To investigate the effects of conjugated linoleic acid added diet feeding on CLA accumulation and quality characteristics of pork meat. The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. Pigs were divided into 5 treatment groups(4 pigs/group) and subjected to one of five treatment diets(0, 1.25% CLA for 2 weeks, 2.5% CLA for 2 weeks, 1.25% CLA for 4 weeks and 2.5% CLA for 4 weeks, CLA diets; total fed diets) before slaughter. Pork loin were collected from the animals(110 kg body weight) slaughtering at the commercial slaughter house. Pork loin meat were aerobic packaged and then stored during 2, 5, 8, 11 and 14 days at 4$^{\circ}C$. Samples were analyzed for shear force value, texture, TBARS, fatty acid composition, cholesterol and CLA content. CLA treatment groups showed significantly(p〈0.05) higher shear force value compared to those of control group at 11, 14 days of cold storage. All treatments were decreased significantly as the storage period passed. There was a not significantly difference in texture between control and CLA treatment groups. All CLA treatment groups showed significantly(p〈0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. CLA treatment groups showed significantly(p〈0.05) lower cholesterol content compared to those of control group. As dietary CLA was increased in feed, the content of CLA was increased, but the control was almost not detected. The contents of CLA were not significantly changed during chilled storage for 14 days. In the change of fatty acid composition, the contents of oleic, linoleic and arachidonic were decreased by dietary CLA-supplementation, whereas the increase level of CLA-supplementation resulted in the higher palmitic and stearic acid. In all results, CLA could be accumulated in pork meat and its antioxidant capability has been indicated. It was suggested that dietary CLA-supplementation could be produced high quality pork.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.81-99
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• 2020

Origin-destination data have been collected and utilized for demand analysis and service design in various fields such as public transportation and traffic operation. As the utilization of big data becomes important, there are increasing needs to store raw origin-destination data for big data analysis. However, it is not practical to store and analyze the raw data for a long period of time since the size of the data increases by the power of the number of the collection points. To overcome this storage limitation and long-period pattern analysis, this study proposes a methodology for compression and origin-destination data analysis with the compressed data. The proposed methodology is applied to public transit data of Sejong and Seoul. We first measure the reconstruction error and the data size for each truncated matrix. Then, to determine a range of principal components for removing random data, we measure the level of the regularity based on covariance coefficients of the demand data reconstructed with each range of principal components. Based on the distribution of the covariance coefficients, we found the range of principal components that covers the regular demand. The ranges are determined as 1~60 and 1~80 for Sejong and Seoul respectively.

• The Korean Journal of Nuclear Medicine
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• v.5 no.2
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• pp.19-40
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• 1971

Since the iron balance is maintained by regulated intestinal absorption rather than regulated excretion, there have been many reports concerning the factors which may influence the intestinal iron absorption. As the liver is the largest iron storage organ of the body, any hepatocellular damage may result in disturbances in iron metabolism, e,g., frequent co-existence of hemochromatosis and liver cirrhosis, or elevated serum iron level and increased iron absorption rate in patients with infectious hepatitis or cirrhosis. In one effort to demonstrate the influence of hepatocellular damage on intestinal iron absortion, the iron absorption rate was measured in the rabbits whose livers were injured by a single subcutaneous injection of carbon tetrachloride (doses ranging from 0.15 to 0.5cc per kg of body weight) or by a single irradiation of 2,000 to 16,000 rads with $^{60}Co$ on the liver locally. A single oral dose of $1{\mu}Ci\;of\;^{59}Fe$-citrate with 0.5mg of ferrous citrate was fed in the fasting state, 24 hours after hepatic damage had been induced, without any reducing or chelating agents, and stool was collected for one week thereafter. Serum iron levels, together with conventional liver function tests, were measured at 24, 48, 72, 120 and 168 hours after liver damage had been induced. All animals were sacrificed upon the completing of the one week's test period and tissue specimens were prepared for H-E and Gomori's iron stain. Following are the results. 1. Normal iron absorption rate of the rabbit was $41.72{\pm}3.61%$ when 0.5mg of iron was given in the fasting state, as measured by subtracting the amount recovered in stool collected for 7 days from the amount given. The test period of 7 days is adequate, for only 1% of the iron given was excreted thereafter. 2. The intestinal iron absorption rate and serum iron level were significantly increased when the animal was poisoned by a single subcutaneous injection of 0.15cc. per kg. of body weight of carbon tetrachloride or more, or the liver was irradiated with a single dose of 12,000 rads or more. The results of liver function tests which were done simultaneously remained within normal limit except SGOT and SGPT which were somewhat increased. 3. In each case, there has been good correlation between the extent of liver cell damage and degree of increased iron absorption rate or serum iron level. 4. The method of liver damage appeared to make no obvious difference in the pattern of iron deposit in liver. This may be partly due to the fact that tissue specimens were obtained too late, for by this time the elevated serum iron level had returned within normal range and the pathological changes were almost healed. 5. The possible factors and relationship between intestinal iron absorption and hepatic parenchymal cell damage has been discussed.

• Water for future
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• v.28 no.3
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• pp.187-195
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• 1995

This study aims at suggesting an alternative to improve current capacity of flood control for the existing Soyanggang multi-purpose dam which was constructed 20 years ago as a largest dam in Korea. The newly estimated value of the probable maximum precipitation(PMP) is 760.0 mm which is based on the hydrometeorological method. The peak inflow of 1000 years return period at the time of construction was 13,500$m^3$/s. However, the newly estimated peak inflow of the PMF is 18,100$m^3$/s which is 1.34 times bigger than the original one. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared; (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing one, (3) raising the existing dam crest, (4) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang multipurpose dam. The preliminary evaluation of these alternatives resulted in that the second alternative is most economical and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multi-purpose dam, a detailed study of an additional spillway tunnel has to be followed.

• Journal of Conservation Science
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• v.32 no.2
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• pp.273-291
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• 2016

Some ceramic artifacts representing time-wise from comb pattern pottery in the Neolithic Age to white porcelain in Joseon Dynasty were selected from 7 sites in the north and south area of Charyeong Mountain Range in order to making techniques interpretation and development process of ancient ceramics through physicochemical and mineralogical quantitative analysis. Studied pottery samples in the Prehistoric times showed trace of ring piling in soft-type, and pottery in the Three Kingdoms Period had both soft and hard-type but kettle-ware and storage-ware were made with ring piling, but table-ware was made by wheel spinning. Different from pottery after the Three Kingdom Period when refinement of source clay was high, pottery in the Neolithic Age and in the Bronze Age exhibited highly mineral content in sandy source clay, which showed a lot of larger temper than source clay. Groundmass of celadon and white porcelain almost did not reveal primary minerals but had high content of minerals by high temperature firing. Ceramic samples showed some different in major and minor elements according to sites irrespective of times. Geochemical behaviors are very similar indicating similar basic characteristics of source clay. However, loss-on-ignition showed 0.01 to 12.59wt.% range with a large deviation but it rapidly decreased moving from the Prehistoric times to the Three Kingdom Period. They have correlation with the weight loss due to firings, according to burning degree of source clay and detection of high temperature minerals, estimated firing temperatures are classified into 5 groups. Pottery in the Neolithic Age and in the Bronze Age belongs from 750 to $850^{\circ}C$ group; pottery in the Three Kingdom Period are variously found in 750 to $1,100^{\circ}C$ range of firing temperature; and it is believed celadon and white porcelain were baked in high temperature of 1,150 to $1,250^{\circ}C$. It seems difference between refinement of source clay and firing temperature based on production times resulted from change in raw material supply and firing method pursuant to development of production skill. However, there was difference in production methods even at the same period and it is thought that they were utilized according to use purpose and needs instead of evolved development simply to one direction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.383-391
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• 2021

To develop a cultivation method for the mass production of sweetpotato cultivars, 'Juhwangmi' (orange tuber) and 'Sinjami' (puple tuber), the yield of tuber roots and content of various functional substances were analyzed according to planting intervals and growing periods. For 'Juhwangmi, the total yield of tubers was increased by respectively 36% and 54% and the yield of tubers over 300 g was increased by respectively 170% and 221% in the 140-day and 160-day cultivation plots compared with that in the 120-day cultivation plot at the 70×20 cm planting interval. Similarly, the total content of beta-carotene in the tubers increased as the cultivation period was extended. In particular, beta-carotene content at the 70×20 cm planting interval was the highest. For 'Sinjami', at the same planting interval, the total yield of tubers and yield of tubers over 300 g significantly increased as the growing period was extended. Within the same cultivation period, the yield of tubers over 300 g and the total anthocyanin content of 'Sinjami' were higher at the 70×30 and 70×35 cm planting intervals than at the 70×20 and 70×25 cm planting intervals in the 140-day and 160-day cultivation plots. Moreover, the total polyphenol and flavonoid content was significantly higher in 'Sinjami' than in 'Juhwangmi', and the values were the highest in the 160-day cultivation plots. In particular, the content of these two functional substances in tubers over 300 g was the highest at the 70×30 and 70×35 cm planting intervals.