• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.235-243
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• 1974

Recenty, the pesticides Pollutions in connection with the maintenance of dietary life are poised as serious sanitary problems. Author have established an appropriate analysis method in this connection and, at the same time, analysed the levels of pesticides residues, such as organochloride pesticides and organic mercurials, contained in main cereals (rice, barley, and wheat) collected throughout the country. Using gas liquid chromatography method, comparative analyses were made of organochloride Pesticides with electron capture detector, and organic mercurials with electron capture detector and the Dithizone Method. As a result, the organic mercurials analysis using gas liquid chromatography is believed to hold out an especially good method for both in terms of its sensitivity and its Practical applications. The summary obtained from these results is as follows; The detectable limit of organochloride pesticides is $5\times10^{-10}$ grams and that of organic mecurials is $5\times10^{-9}$ grams. The detections using the Dithizone Method are difficult. The gas liquid chromatographic analysis of organic mercurials is very simple in its operation and high in its sensitivity, compare with the analysis using the Dithizone Method. Therefore, this analysis is expected to be a good method applicable to the pesticide residues analysis. The levels of pesticide residues contained in samples are very little for tolerance and, therefore, no problem i.: foreseen for eating. The appropriate conditions of gas liquid chromatographic analysis obtained from these results are expected very useful for the date establishing an officially authorized analysis method.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.295-306
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• 2018

Despite the utility of solid-state NMR, NMR studies of iron-bearing silicate glasses remain a challenge because the variations in the peak position and width with increasing iron content reflect both paramagnetic effect and iron-induced structural changes. Therefore, it is essential to elucidate the effect of temperature on the NMR signal for iron-bearing silicate glasses. Here, we report the $^{29}Si$ and $^{27}Al$ MAS NMR spectra for $(Mg_{0.95}Fe_{0.05})SiO_3$ and $Fe_2O_3$-bearing $CaAl_2Si_2O_8$ (anorthite) glasses with varying spinning speed to interpret the NMR spectra for iron-bearing silicate glasses. The increase in the spinning speed results in an increase in the sample temperature. The current NMR results allow us to understand the origins of the changes in NMR signal with increasing iron content and to provide information on the dipolar interaction between nuclear spins. The $^{29}Si$ NMR spectra for $(Mg_{0.95}Fe_{0.05})SiO_3$ glass and $^{27}Al$ NMR spectra for $Fe_2O_3$-bearing $CaAl_2Si_2O_8$ glasses show that the peak shape and position of iron-bearing glasses do not change with increasing spinning speed up to 30 kHz. These results suggest that the NMR signal in the Fe-bearing glasses may stem from the 'survived nuclear spins' beyond the cutoff radius from the Fe, not from the paramagnetic shift. Based on the current results, the observed apparent shifts toward lower frequency of Al peak for $Fe_2O_3$-bearing $CaAl_2Si_2O_8$ glasses with increasing $Fe_2O_3$ at all spinning speed (15 kHz to 30 kHz) indicate the increase in the fraction of ${Q^4}_{Al}$(nSi) with lower n (i.e., 1 or 2) with increasing $Fe_2O_3$ and the spatial proximity between Fe and ${Q^4}_{Al}$(nSi) with higher n (i.e., 3 or 4). The present results show that changes in the NMR signal for iron-bearing silicate glasses reflect the actual iron-induced structural changes. Thus, it is clear that the applications of solid-state NMR for iron-bearing silicate glasses hold strong promise for unraveling the atomic structure of natural silicate glasses.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.13-24
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• 1988

This paper is concentrated on the development of oxygen transfer system by U-tube deep shaft in biological fluidised bed process. The depth of the shaft is 32 m, it is composed of downcomer and riser. Not only flow pattern and oxygen transfer in the deep shaft but also oxygen limitation in biofilm and oxygen utilization in biological fluidised bed are investigated. In this investigation, driving force for liquid circulation in the deep shaft is affected by air injection depth and gas hold-up in downcomer. Flow pattern of the deep shaft is revealed to plug flow. When flow velocity in the deep shaft is maintained to 0.52 m/sec, $K_La$ value is peak at 25~30 m depth in riser. The efficiency of dissolved oxygen supply which passed from the deep shaft to biological fluidised bed is estimated to 56~81 % in the organic wastewater treatment using the deep shaft and when dissolved oxygen concentration is 9.2 mg/l and over, limiting factors of flux and substrate within biofilm are organic materials. Terefore, organic loadings could be increase without decreasing of BOD removal efficiency.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.3
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• pp.309-327
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• 2016

Scholarly monographs have been a main vehicle for knowledge representation and transfer as well as an important research outcome. University presses have long been considered as the last bastion for scholarly monographs that have low commercial prospect. Until now there has not been a systematic data analysis regarding scholarly monograph production by university presses in Korea. In this paper, we collected bibliographic records of university presses' monograph publications between 1950 and 2015 using the National Library of Korea's online catalog system. A total of 21,015 records were used in the analysis. In particular, for monographs published between 2001 and 2015, we categorized them into scholarly monographs and non-scholarly monographs. University presses' publishing showed sharp increase during the 1990's but is in decline after its peak in 2005. University presses seem to have engaged in publishing more non-scholarly monographs than scholarly monographs by a ratio of 6:4. Large university presses in size seem to produce higher proportions of scholarly monographs than smaller presses. In terms of authoring types, single authorship accounts for the highest proportion and on the increase. However, edited books are losing ground as translated books seem to hold steady. Monographs in social sciences have been published more frequently than any other subject areas as there seem to be significant discrepancies among subject areas in terms of the scholarly monograph proportion.

• Culinary science and hospitality research
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• v.16 no.3
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• pp.286-297
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• 2010

This study examines physiochemical characteristics of functional bread with black garlic flour added such as its content, texture, sensory test and quality properties. The loaf volume and weight of black garlic flour-added pan bread showed that for the control, the loaf volume was the greatest, and the more the black garlic flour content increased, the smaller the loaf volume became. The change of crust chromaticity showed that the L value decreased significantly, and crust chromaticity thickened, and as the black garlic flour content increased, a value and b value decreased. The characteristics of texture showed that the hardness and chewiness decreased as the black garlic flour content increased, and gumminess increased significantly while there was no significant difference in cohesiveness. The flavor, taste and texture of pan bread with black garlic flour content didn't showed a significant difference with the control. Consequently, the black garlic flour-added wheat flour was no significant difference with the control up to 3% black garlic flour-added wheat flour, which can be used as a product.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.930-936
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• 2004

Effects of rice cultivars and degree of milling (DM) on composition, pasting properties, total phenolic contents, and distribution of phenolic acids were investigated. Rice and bran fractions with 94.4, 92.0, and 90.4% milling yields from brown rice of four cultivars (Odae, Nampyung, Chucheong, and Ilmi) were used. Fat and ash contents of milled rices decreased with increasing DM, whereas protein contents were not affected. In rice bran, differences in fat and ash contents by cultivars were higher than those caused by DM. With increasing DM, gelatinization temperature of rice flour decreased, whereas peak viscosity and hold viscosity at $95^{\circ}C$ increased. While cold viscosity, final viscosity, and setback varied among cultivars, DM had little effect. Total polyphenolic contents in brown rice, milled rice, and rice bran were 93.9-88.8, 30.3-71.9, and 310.0-541.6 mg catechin eq/100g, respectively. Major phenolic compounds were identified as ferulic and p-coumaric acids. Total phenolic content of brown rice (65.9-27.9 mg%) decreased with increasing DM, whereas ratio of ferulic acid composition increased. Chucheong and Ilmi varieties showed biggest reduction of phenolic acid contents by milling. In rice bran, ferulic and p-coumaric acids were 157.8-240.2 and 31.8-90.4 mg%, respectively. Contents of sinapinic, benzoic, and m-hydroxybenzoic acids in rice bran were higher than those of brown and milled rices.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.3-4
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• 2000

Many researchers are interested in the synthesis and characterization of carbon nitride and diamond-like carbon (DLq because they show excellent mechanical properties such as low friction and high wear resistance and excellent electrical properties such as controllable electical resistivity and good field electron emission. We have deposited amorphous carbon nitride (a-C:N) thin films and DLC thin films by shielded arc ion plating (SAIP) and evaluated the structural and tribological properties. The application of appropriate negative bias on substrates is effective to increase the film hardness and wear resistance. This paper reports on the deposition and tribological OLC films in relation to the substrate bias voltage (Vs). films are compared with those of the OLC films. A high purity sintered graphite target was mounted on a cathode as a carbon source. Nitrogen or argon was introduced into a deposition chamber through each mass flow controller. After the initiation of an arc plasma at 60 A and 1 Pa, the target surface was heated and evaporated by the plasma. Carbon atoms and clusters evaporated from the target were ionized partially and reacted with activated nitrogen species, and a carbon nitride film was deposited onto a Si (100) substrate when we used nitrogen as a reactant gas. The surface of the growing film also reacted with activated nitrogen species. Carbon macropartic1es (0.1 -100 maicro-m) evaporated from the target at the same time were not ionized and did not react fully with nitrogen species. These macroparticles interfered with the formation of the carbon nitride film. Therefore we set a shielding plate made of stainless steel between the target and the substrate to trap the macropartic1es. This shielding method is very effective to prepare smooth a-CN films. We, therefore, call this method "shielded arc ion plating (SAIP)". For the deposition of DLC films we used argon instead of nitrogen. Films of about 150 nm in thickness were deposited onto Si substrates. Their structures, chemical compositions and chemical bonding states were analyzed by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. Hardness of the films was measured with a nanointender interfaced with an atomic force microscope (AFM). A Berkovich-type diamond tip whose radius was less than 100 nm was used for the measurement. A force-displacement curve of each film was measured at a peak load force of 250 maicro-N. Load, hold and unload times for each indentation were 2.5, 0 and 2.5 s, respectively. Hardness of each film was determined from five force-displacement curves. Wear resistance of the films was analyzed as follows. First, each film surface was scanned with the diamond tip at a constant load force of 20 maicro-N. The tip scanning was repeated 30 times in a 1 urn-square region with 512 lines at a scanning rate of 2 um/ s. After this tip-scanning, the film surface was observed in the AFM mode at a constant force of 5 maicro-N with the same Berkovich-type tip. The hardness of a-CN films was less dependent on Vs. The hardness of the film deposited at Vs=O V in a nitrogen plasma was about 10 GPa and almost similar to that of Si. It slightly increased to 12 - 15 GPa when a bias voltage of -100 - -500 V was applied to the substrate with showing its maximum at Vs=-300 V. The film deposited at Vs=O V was least wear resistant which was consistent with its lowest hardness. The biased films became more wear resistant. Particularly the film deposited at Vs=-300 V showed remarkable wear resistance. Its wear depth was too shallow to be measured with AFM. On the other hand, the DLC film, deposited at Vs=-l00 V in an argon plasma, whose hardness was 35 GPa was obviously worn under the same wear test conditions. The a-C:N films show higher wear resistance than DLC films and are useful for wear resistant coatings on various mechanical and electronic parts.nic parts.

• Journal of Sericultural and Entomological Science
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• v.25 no.1
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• pp.34-43
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• 1983

These studies have been carried out to find better locations for sericultural service regardless of the international silk market fluctuation in Korea. In order to acieve the purpose, various investigations and analyses have been carried out for more than four hundred sericultural communities to find out the main factors which caused to decrease in cocoon production in spite of a gloomy past silk market. Now, we believe that we have set up some fundamental guide lines in developing sound serviceable sericultural communities in Korea in case the government accepts the written advices, and the results obtained are as follows: 1. The Korean sericulture has been very prosperous from the 60's to the 70's. In 1976 the cocoon production was at its peak, reaching 41,704M/T from which its decline took place with annual averages of 18.5% for total cocoon production and 16.4% for mulberry field. These figures represent a quantitative decrease to one-third of the total amount in 1976. Since then, the Korean sericulture had continuously suffered from a shortage of raw silk resulting in a slow development of sericulture. At present, a steady development through all possible measures is great importance. 2. The downfall of the korean sericulture resulted from two factors of such as the external, which led to the decline in the price of raw silk at the international market and restrain of import and, the internal, resulting in the little increase of cocoon price and a comparatively lower benefits from the sericulture than from other cash crops. 3. The already established sericultural zone collapsed and then reorganized with the outstanding regional specialization so the decline in total cocoon production in the country. Based on the agricultural regions, 1980 cocoon production was very stable in the mountaineaus area of the east-south which used with intercropping. In this area there was small decline of 33% compare with that of the 1979, and with 70% decline in the dry field farming area of Kangwon Do. In an administrative districtwise, six counties beginning with Sanchnung county of Kyungsang Nam Do, showed less than 20% decline of cocoon production, sixteen counties beginning with Samchuck county of Kangwon Do marked above 80% decrease of cocoon production. In the smaller unit area-wise, there was a big difference among them. twenty-five myons rather increased and a hundrd fourty-three myons decreased above 80% of it. 4. The cocoon production was positively correlated with the decreasing percentage of cocoon production per household. It was also affected by the ratio of the mulberry field area to the total cultivated area per household and cocoon productivity per 10a. 5. Four hundred sixty-four villages in the seventeen counties were surveyed on the basis of farm management and techniques concerned ('80/'79), and then the results were evaluated by using of computer. These results are summarized as foolows: (1) Cocoon production per household There was no difference among the agricultural regions in cocoon production. The cocoon production per household in the comparatively stable villages increased from 100.8kg in 1979 to 122kg in 1981. Cocoon yield in the stable villages decreased by 20% of '81/'79. The cocoon production per house hold in while that of the unstable villages decreased by more than 40% from 102.9kg in 1979 to 82kg in 1981. (2) Cocoon yield per 10a mulberry field The cocoon yield per 10a was higher in the plain area than in the mountaineous area. The stable villages had an average of 73.4kg cocoon yield/10a while the unstabe ones had only an average of 55kg. (3) Adoption the mulberry branch rearing method The branch rearing method was more popular in the plain area than in the mountainous area. In the stable vilages adopted 24.2% in spring and 16.7% in autumn of 1979. In 1981 it shwed increases of 34.3% and 10.1% in the two seasons respectivly. However, the unstable villages showed 13.3% and 126% in both seasons, respectively. (4) The patterns of the combined management system in the sericultural farming The popular management system in the sericultural from was combined with rice and other cash crops, showing 55% of the total households surveyed. Fourteen percent of the households combined the management system with rice and other cash crops and 14% of the households combined with rice only. The villages wich earned less than 20% of the total income from the sericulture reached 81% of the total houscholds indicating that they were still far beyond a complete combination system. (5) Damage by agricultural chemicals The damage caused by agricultural chemicals was mainly due to the protection of rice against insectpests and diseases in the plain areas and took place mostly in the autumn season. The chemicals applied was 65% of Iiquid and 35% of powder forms and 35% of damage was from granulat form of the chemicals. The use of the granular chemicals was low because of high cost.