• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.143-156
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• 2015

In order to understand the dynamic characteristics of water column environments in the Western Pacific seamount area (approximately $150.2^{\circ}E$, $20^{\circ}N$), we investigated the water mass and the behavior of water column parameters such as dissolved oxygen, inorganic nutrients (N, P), and chlorophyll-a. Physico-chemical properties of water column were obtained by CTD system at the nine stations which were selected along the east-west and south-north direction around the seamount (OSM14-2) in October 2014. From the temperature-salinity diagram, the main water masses were separated into North Pacific Tropical Water and Thermocline Water in the surface layer, North Pacific Intermediate Water in the intermediate layer, and North Pacific Deep Water in the bottom layer, respectively. Oxygen minimum zone (OMZ, mean $O_2$ $73.26{\mu}M$), known as dysoxic condition ($O_2<90{\mu}M$), was distributed in the depth range of 700~1,200 m throughout the study area. Inorganic nutrients typified by nitrite + nitrate and phosphate showed the lowest concentration in the surface mixed layer and then gradually increased downward with representing the maximum concentration in the OMZ, with lower N:P ratio (13.7), indicating that the nitrogen is regarded as limiting factor for primary production. Vertical distribution of water column parameters along the east-west and south-north station line around the seamount showed the effect of bottom water inflowing at around 500 m deep in the western and southern region, and concentrations of water column parameters in the bottom layer (below 2,500 m deep) of the western and southern region were differently distributed comparing to those of the other side regions (eastern and northern). The value of Excess N calculated from Redfield ratio (N:P=16:1) represented the negative value throughout the study area, which indicated the nitrogen sink dominant environments, and relative higher value of Excess N observed in the bottom layer of western and southern region. These observations suggest that the topographic features of a seamount influence the circulation of bottom current and its effects play a significant role in determining the behavior of water column environmental parameters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.25-35
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• 1989

To prepare a new type of fish sauce from skipjack scrap, it was examined the effect of koji on the sauce flavor, conditions of low salt fish sauce processing and the changes of taste com-pounds during its fermentation. To prepare the skipjack scrap sauce, chopped skipjack head paste was mixed with $6.6\%$ skipjack viscera, $26.9\%$ koji, $71\%$ of $25\%$ brine, $13.3\%$ salt and $7.6\%$ glucose, and fermented at $25\pm4^{\circ}C$ for 90 days. The same process was also carried out to prepare the low salt skipjack scrap sauce adding $7.6\%$ sorbitol, $0.3\%$ lactic acid and $9.8\%$ ethyl alcohol instead of $13.3\%$ salt. The major free amino acids in the products were glutamic acid, Iysine, valine, phenylalanine, alanine, leucine and isoleucine at 90 days of fermentation. And the contents of total free amino acids in both products were 3,307mg/00m1, 3,637.1mg/100m1 at 90 days of fermentation. The predominating non-volatile organic acids showed in the products were lactic acid, succinic acid, pyroglutamic acid, which were $90\%$ over contents of the total non-volatile organic acids. Total non-volatile organic acid contents in both products were 1,002.1mg/100ml, 1,312.9mg/100m1 at 90 days of fermentation. During fermentation of sauce, ADP, AMP and IMP were decreased, while inosine and hypoxanthine were increased. The major taste compounds of the products were rove진ed free amino acids and non-volatile organic acids. The nucleotides and their related compounds, total creatinine, betaine, TAMO and sugar were seemed to be having an auxiliary role in taste of those products. Fishy odor in skipjack scrap sauce can be improved by adding koji. And the low salt skipjack scrap sauce ($9.12\%$ of salt contents) can be prepared by the replacement of a part of salt with sorbitol, lactic acid and ethyl alcohol. From the results of sensory evaluation and chemical experiments, the skipjack scrap sauce products supposed to be at least equal to the sold soy sauce on the market in quality.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.212-222
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• 2004

The application of acidulated phosphate fluoride gel(APF) and fluoride varnishes are the most common topical fluoride therapy. The purpose of this in vitro study was to compare the remineralization effects of two topical fluoride agents, APF gel and fluoride varnish with microtomograph and 3D image analyzer without sample preparation and chemical fixation. For the purpose of the study, the artificial caries lesion was caused on the caries-free permanent pre molar and 48 specimens were divided into three groups each containing 16 specimens No application was performed on group 1, which acted as control group. Group 2 was treated with APF gel and was removed after a minute. Group 3 was treated with the topical application of fluoride varnish and removed after 45 minutes. Each specimen was placed into a closed container with 50ml of a artificial saliva during three months and the 3D images of the remineralization area were taken using the SkyScan each month. Using the density-measuring program in V $works^{TM}$, the density value of the remineralization area was measured. The following results were obtained: 1. All groups demonstrated an increase in the density of artificial caries lesion with time. 2. The density was significantly higher in APF gel and fluoride varnish group than control group at 1 month, 2 months, 3 months after the treatment(P<0.05). 3. The difference of the density between that "prior to treatment" and that "1 month after treatment" in Group 2 and Group 3 was significantly higher than that of Group 1 and, the difference of the density between that "1 month after treatmen" and that "2 month after treatment" in Group 3 was significantly higher than that of Group 1 and 2(P<0.05). 4. The fluoride varnish was more effective after 2 and 3 months and continuous than the APF gel.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.202-218
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• 1976

In this experiment American Summer Pairman apple was selected as test fruit in order to study the effect of sub-atmospheric pressure storage in the apple. keeping a certain pressure condition, a new sub-atmospheric pressure system was designed and constructed in which fruits were stored at $25^{\circ}C$ under two different atmospheric pressure conditions such as Normal Atmospheric Pressure (NAP) and Sub-Atmospheric Pressure (SAP). Moreover, they were divided into plots of 5% and 0% of $CO_2$, on the basis of gas composition. Under these conditions, the amount of respiration and ethylene evolution, and the changes of intercellular gas composition and organic components were investigated throughout the storage. The results obtained are as follows: (1) The intercellular gas was exhausted so rapidly by the SAP treatment that the gas equilibrium in the tissues reached within 5 minutes. (2) The amount of respiration was found to be higher in plots of NAP than SAP, and under the conditions, controlling $CO_2$ content, plots of $CO_2$ 5% were lower in the amount of respiration than $CO_2$ 0%. The climateric rise was revealed more slowly in plots of the SAP than NAP. These results indicate that the SAP treatment was an efficient method for controlling the respiration of fruits. Furthermore, these results were also realized with the results of the respiratory quotient (R.Q) and intercellular gas composition. (3) Evolution of ethylene, the ripening hormone in plant, was shown the similar tendency to the climacteric pattern of respiration; at the stage of climacteric maximum, the maximun amount of ethylene was found earlier in plots of NAP than SAP, and post climacteric stage was prolonged in the plots of the SAP compared to those of the NAP. The ethylene concentration in tissue appeared lower in plots of the SAP than NAP, which might suggest that the SAP treatment was caused to restriction of ethylene evolution. (4) Effects of the SAP treatment mentioned hitherto were proved also with the test of the external appearance such as changes of color and freshness, firmness, rotting and weight loss. (5) In the investigation of organic components, vitamin C and organic acids varied less in plots of SAP than NAP. Specially, it was remarkable that the loss of malic acid was least decreased by the SAP treatment. These effects of the SAP treatment were distinctive in the changes of the ratios of malic and citric acid to total acid, and the ratios of free sugar to free acid.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.51-63
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• 2013

To assess the effect of environmental factors on the sustainability of cultured production shellfish, we investigated the habitat characteristics of tidal flat (Namhae-po in Taean). We measured the physiochemical parameters (temperature, salanity, pH, dissolved oxygen and nutrients) and the geochemical characteristics (chemical oxygen demand, ignition loss, C/N ratio and C/S ratio). Surface sediments were collected from several site of tidal flat to examine the geochemical characteristics of both the benthic environment and heavy metal pollution. The grain size for research area of tidal flat were similar at the ratio of silt and clay in comparison with the other site of it. The C/N ratio was more than 5.0, reflecting the range arising from the mix of marine organism and organic matter. The C/S ratio (about 2.8) showed that survey area had anoxic or sub-anoxic bottom conditions. The enrichment factor (Ef) and index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. Adult surf clam (Mactra veneriformis) density was highest at St. 2 (middle part of the Namhae-po), on the other hand, surf clam spat density was highest at St. 3 (lower part of the Namhae-po). Heavy rain, terrigenous suspended clay with fresh water from neighboring agricultural land, and severe high air temperature during summer could be thought as detrimental causes of spat and adult mortality in Namhae-po tidal flat. We suggested that the growth of shellfish in the tidal flat was effected by the various environmental conditions, so an improvement in the cultured method was needed.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.452-460
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• 2007

Ultra-low loss ZERODUR and fused silica mirrors were manufactured and their light scattering characteristics were investigated. For this purpose, ZERODUR and fused silica substrates were super-polished by the bowl feed method. The surface roughness were 0.292 ${\AA}$ and 0.326 ${\AA}$ in rms for ZERODUR and fused silica, respectively. To obtain the high reflectivity, 22 thin film layers of $SiO_2$ and $Ta_2O_5$ were deposited by Ion Beam Sputtering. The measured light scattering of ZERODUR and fused silica mirror were 30.9 ppm and 4.6 ppm, respectively. This shows that the substrate surface roughness is not the only parameter which determines the light scattering of the mirror. In order to investigate the mechanism for additional light scattering of the ZERODUR mirror, the surface roughness of the mirror was measured by AFM and was found to be 2.3 times higher than that of the fused silica mirror. It is believed that there is some mismatch at the interface between the substrate and the first thin film layer which leads to the increased mirror surface roughness. To clarify this, the contact angle measurements were performed by SEO 300A, based on the Giriflaco-Good-Fowkes-Young method. The fused silica substrates with 0.46 ${\AA}$ in its physical surface roughness shows lower contact angle than that of the ZERODUR substrate with 0.31 ${\AA}$. This indicates that the thin film surface roughness is determined by not only its surface roughness but also the surface energy of the substrate, which depends on the chemical composition or crystalline orientation of the materials. The surface energy of each substrate was calculated from a contact angle measurement, and it shows that the higher the surface energy of the substrate, the better the surface roughness of the thin film.

• Clean Technology
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• v.24 no.3
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• pp.198-205
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• 2018

This study investigated the influence of catalyst preparation on the activity of $Co-CeO_2$ catalyst for $N_2O$ decomposition. $Co-CeO_2$ catalysts were synthesized by co-precipitation and incipient wetness impregnation. In order to estimate the performance of the as prepared catalysts, direct catalytic $N_2O$ decomposition test was carried out under $250{\sim}375^{\circ}C$. As a result, the catalyst prepared by co-precipitation (CoCe-CP) showed an enhanced performance on $N_2O$ decomposition reaction even in the presence of $O_2$ and/or $H_2O$, whereas the impregnation catalyst (CoCe-IM) did not. In order to investigate the difference in catalytic activity, characterization such as XRD, BET, TEM, $H_2-TPR$, $O_2-TPD$, and XPS was conducted. It is confirmed that the particle size and specific surface area were changed depending on the catalyst preparation method and the synthesis process influenced the physical properties of the catalysts. In addition, the improvement in the activity of the catalyst prepared by co-precipitation is due to the enhanced reduction from $Co^{3+}$ to $Co^{2+}$ and the improved oxygen desorption rate. However, it has been confirmed that the surface electron state and binding energy, which are related to $N_2O$ decomposition, do not change depending on the preparation method.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.63-71
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• 2009

Two experiments were conducted to investigate feed value of Yukmijihwangtang (herbal medicine) meal. In experiment 1, the chemical composition of Yukmijihwangtang ingredients was determined before and after extraction, and investigated the effects of partial substitution of dried Yukmijihwangtang meal on TMR for fattening cattle. In experiment 2, nine Korean native male goats were employed to investigate the palatability and ruminal parameters of Yukmijihwangtang meal silages. In experiment 1, the crude protein content after water extraction was higher in Alisma orientale Juzepczuk (Teaksa), and lower in Pachyma hoelen Rumph (Bokryeong). the crude fat content after water extraction was higher in Cornus officinalis Sieb. et Zucc (Sansuyu), and lower in other ingredients. ADF content after water extraction of Cornus officinalis Sieb. et Zucc (Sansuyu) was higher compared to those of Pachyma hoelen Rumph (Bokryeong) and Paeonia suffruticosa Andrews (Mokdanpi). Dioscorea japonica Thunberg (Sanyak) was the lowest in ADF content. Dry matter disappearance was increased by adding Yukmijihwangtang meal to TMR. In experiment 2, feed intakes of Yukmijihwangtang silage containing molasses (0.5 and 1%) for 30 min and 6 hr were significantly higher than that of control (0%) in Korean native goats. In various ruminl parameters, molasses addition to silage materials trended to increase total VFA, propionate and valerate contents, but trended to decrease iso-butylate, butylate and iso-valerate contents in Korean native goats. In conclusion, Yukmijihwangtang meal could be used as partial substitution of low level in TMR for fattening cattle. Molasses supplementation to silage materials contained with herbal medicine meal could improve its nutritional quality and palatability for Korean native goats. One percent level of molasses addition could give a useful effect in ensiling.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.237-243
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• 2007

The objective of this experiment was to investigate the feeding influence of Prunus memu by-products (PMB) on productivity, blood composition, meat quality and intestinal microflora in semi-broiler chicks. Four hundred one day old chicks(Hanhyup 3) were raised in the floor pen with five treatments(0, 0.5, 1.0 2.0 3.0%) of four replicate for ten weeks. Basal diets contained 3,000, 3,100, 3,100, 3,200 kcal/kg ME and 22, 21, 19, 17% CP, respectively. There were no different performance for the first two weeks, but showed significantly different weight gain, feed intake in PMB 2.0, 3.0% addition treatments compared with control from three to five weeks of age. Weight gain of birds fed 2.0% PMB was significantly higher from nine to 10 weeks of age than control(P<0.05). Total weight gain tended to increase in PMB 1.0, 2.0, 3.0% addition treatments. Feed intake also showed increase in PMB 2.0, 3.0% addition treatments, but there were no different feed conversion. Total protein, albumin, cholesterol, neutral fat, glucose was significantly decreased in PMB 0.5% addition treatments compared with control. There were no different physico-chemical characteristics in breast meat. The number of yeast was significantly improved in PMB 3.0% compared with control(P<0.05), but found no difference in number of E. coli between control and PMB treatments. ND titer of birds fed PMB was not statistically different, but tended to decrease as dietary PMB increased. As the result of this experiment, PMB would be available as a feed additives in semi-broiler chicks.

• Journal of Life Science
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• v.27 no.4
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• pp.390-397
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• 2017

Iron (Fe) is an important micronutrient for the health and growth of plants. Iron is usually provided by fertilizers, and iron-chelate fertilizers are well absorbed by plants. This study presents the plant growth-promoting effects of a new functional iron fertilizer, Fe-chelating crab shell powder (FCSP), which is generated from the chelation of Fe ions with crab shell powder. Iron chelate was derived from spent pickling liquor, which is rich in reductive iron, iron(II) oxide. To analyze the effects of FCSP on plant growth, we treated lettuce with several concentrations of FCSP in both lab- and field-scale experiments. In the lab-scale test, the treatment of 50 ppm of FCSP highly promoted growth and resulted in increases in the size, weight, number and chlorophylls content of leaves of plants compared to the treatment of crab shell powder. Fifty ppm of FCSP also increased the size and weight of leaves up to 2 times compared to the application of chemical fertilizer and/or compost in field conditions. In addition, the FCSP treatment resulted in the highest ion uptake of Fe in lettuce leaves. Moreover, FCSP led to increases in the amounts of Fe, Ca, available phosphorus and organic matter in treated soil, indicating that soil quality was improved. Taken together, our results demonstrate that FCSP promotes lettuce growth via enhancement of Fe availability and improves soil quality. Therefore, FCSP can be utilized as a new functional iron fertilizer.