• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.61-67
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• 2015

Effect of tillage on time of initial runoff, runoff coefficient, NPS pollution load, soil erosion and crop productivity were studied. Eight runoff plots of $5{\times}30m$ on loamy sand field that were 4 respective plots of 3 % and 8% slope were prepared. Treatment included conventional tillage (CT) and no-till (NT). Time of initial runoff from NT retarded between 247~261 % compared with that from CT. Under 3% slope, runoff coefficient in NT was 63.5 % lower than that in CT. The reduction under 8 % slope was 61.7 %. Differences in runoff reduction between 3% and 8% plots were not significant. NT could reduce more than 60 % of NPS pollution and between 50~85 % of sediment if compared with CT. Productivity of NT was also shown that it was not lower than that of CT. It was expected that the results could be used as a fundamental data for estimating a reduction load in Korea TMDL from a no-till BMP on loamy sand agricultural fields.

• Journal of Ocean Engineering and Technology
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• v.27 no.2
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• pp.75-79
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• 2013

This study was carried out to investigate the precipitation behavior of the ${\chi}$ phase and the impact toughness of 25%Cr-7%Ni-2%Mo-4%W super duplex stainless steel. The ${\chi}$ phase was precipitated in the early stage of aging, and with the increasing aging time. However, after reaching a maximum value, the number decreased as a result of the gradual transformation of the ${\chi}$ phase into the ${\sigma}$-phase. It was proved that the ${\chi}$ phase was an intermetallic compound, which represented a lower nickel concentration, higher chromium and molybdenum concentrations, and very higher tungsten concentration compared to the matrix phases. It also showed higher molybdenum and tungsten concentrations than the ${\sigma}$ phase. The decomposition of the ferrite phase into the ${\gamma}_2$ and ${\sigma}$ phases was retarded by W substitution for Mo. Thus, the number of ${\chi}$ phases increased. The impact value was decreased by the substitution of W for Mo. The impact toughness rapidly decreased with time when the ${\chi}$ phase began to precipitate in the initial stage of aging. The impact toughness was, therefore, greatly influenced for the precipitation of the ${\chi}$ phase.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.197-205
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• 2004

Batch test methods have developed for a long time to measure kinetic and stoichiometric parameters which are required to perform steady state design and mathematical modelling of activated sludge processes. However, at various So/Xo ratios, abnormal behaviors of ordinary heterotrophic organism in batch tests have been reported in many researches. Thus, in this research, abnormal behaviors of heterotrophs in batch tests were investigated at various So/Xo conditions by measuring and interpreting oxygen utilization rate. As So/Xo ratio increased, the calculated values of maximum specific growth rates, ${\mu}_{H,max}$ and $K_{MP,max}$, increased. However, at a certain point of So/Xo (around 10mgCOD/mgMLAVSS), ${\mu}_{H,max}$ and $K_{MP,max}$ values started to decrease. According to this observation, three prominent behaviours of heterotrophs were identified at various So/Xo conditions. (1) At low So/Xo region (below 5 mgCOD/mgMLAVSS), the oxygen utilization rate of heterotrophs in batch tests were almost stable and consequently yielded lower maximum specific growth rate. (2) At high So/Xo region (up to 5~10 mgCOD/mgMLAVSS), oxygen utilization rate incresed sharply with time and indicated more upward curvature than the predicted OUR with conventional activated sludge model, which consists of single hetetrotrophs group. Thus, in this region, competition model of two organisms, fast-grower and slow-grower, seemed to be appropriate. (3) At extremely high So/Xo region (over 10mgCOD/mgMLAVSS), significant oxygen utilization rate was still observed even after depletion of readily biodegradable COD. This might be caused by retarded utilization of intermediates which were generated by self inhibition mechanism in the process of RBCOD uptake.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.355-370
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• 2019

The present study aimed at evaluating effects of traditional sauce type and storage time on shelf-life and flavor compounds of marinated pork cooked by Sous-Vide method. Five different traditional sauces (Meju soy sauce, Brewed soy sauce, Fish-soy sauce, Ishiru fish sauce and Anchovy fish sauce) purchased from Asian countries were used. After marination with the sauces, polyvinylchloride film bags containing the marinated pork samples were cooked using Sous-Vide method for $55^{\circ}C$ for 5 h and $60^{\circ}C$ for 30 min, and were then stored for 8 wk at $10^{\circ}C$. Results showed that the pork samples marinated with the sauces retarded the growth of total plate counts (TPC) during storage. At $8^{th}$ wk storage, TPC counts were significantly lower in all samples marinated with the sauces compared to control (p<0.05). Lipid oxidation level was significantly lower in the T2 (Meju soy sauce) and T6 (Anchovy fish sauce) compared to those of T3 (Brewed soy sauce) and T5 (Ishiru fish sauce) or control after 8 wk storage (p>0.05). Forty volatile flavor compounds were detected from the control and marinated samples at $4^{th}$ wk of storage. The pork marinated with Anchovy fish sauce presented significantly higher amounts of importantly pleasant flavor compounds such as; pyrazines and sulfurcontaining compounds than those marinated with other remaining sauces and control. It is concluded that the marination with Anchovy fish sauce partly improved the shelf-life and increased amounts of pleasant flavor compounds of Sous-Vide cooked pork products during storage in comparison to the other remaining sauces.

• The Journal of the Acoustical Society of Korea
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• v.31 no.1
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• pp.19-28
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• 2012

The time-domain solution from the Kirchhoff integral equation for an exterior problem is not unique at certain eigen-frequencies associated with the fictitious internal modes as happening in frequency-domain analysis. One of the solution methods is the CHIEF (Combined Helmholtz Integral Equation Formulation) approach, which is based on employing additional zero-pressure constraints at some interior points inside the body. Although this method has been widely used in frequency-domain boundary element method due to its simplicity, it was not used in time-domain analysis. In this work, the CHIEF approach is formulated appropriately for time-domain acoustic boundary element method by constraining the unknown surface pressure distribution at the current time, which was obtained by setting the pressure at the interior point to be zero considering the shortest retarded time between boundary nodes and interior point. Sound radiation of a pulsating sphere was used as a test example. By applying the CHIEF method, the low-order fictitious modes could be damped down satisfactorily, thus solving the non-uniqueness problem. However, it was observed that the instability due to high-order fictitious modes, which were beyond the effective frequency, was increased.

• Journal of Life Science
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• v.19 no.2
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• pp.289-298
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• 2009

Effects of Nattokinase fibrinol (NKF), defined as a fibrinolytic product, on fibrinolytic and atherogenetic markers were studied for healthy adults (20-31 years old), who is smoking more than 20 cigarettes per day. Subjects were divided into 29 for NKF group and 10 for placebo group in a short term study. They were given 2 tablets of NKF (4,000 unit) or placebo tablet and thereafter blood samples were collected at 0, 2, 4 hr prerid. For a 4-week long term study, 15 subjects for NFK group and 10 subjects for placebo group were supplemented one tablet of each NKF (2,000 unit) and placebo per day, respectively. Blood samples were collected at 0, 1, 2, 4 weeks later. The short-term experimental trial showed that NKF remarkably increased fibrinolytic activity at 2hr after consumption, which was maintained up to 4 hr, relative to that of placebo, while NKF reduced the euglobulin clot lysis time (ECLT) and retarded the activated partial thromboplastin time (aPTT), as compared to placebo group. NKF supplementation for 4 weeks elevated fibrinolytic activity, shortened ECLT and retarded aPTT. Furthermore, NKF supplementation increased anti-atherogenic index by decreasing triglyceride (TG) and elevating high-density lipiprotein (HDL)-cholesterol. These results indicate that NKF supplementation for short term or long term might have beneficial effects on preventing and treating cardiovascular disease by increasing fibrinolytic activity and improving atherogenic markers such as hyperlipidemia.

• Korean Journal of Animal Reproduction
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• v.5 no.1
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• pp.43-63
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• 1981

This study aimed to determine the effects of adrenalectomy on the sexual gland, the thyroid gland and the serum components. A total of 192 Wister strain albino rats were evenly divided into 4 sexually equal groups for the comparisons. Each groups was divided into a control and a treatment group by sexuality. Each tissue of the sexual gland and the thyroid gland was microscopically examined, and at the same time body weight and serum components were also examined on the 1st, 7th, 14th, 28th, 42nd, 56th, 70th and 84th day respectively following adrenalectomy. The results obtained were as follows: 1. The body weight was sufficiently retarded in decreasingly after the adrenalectomy as compared to that of control. 2. The histological change of testis started atrophy of spermatogonia and degeneration of spermatocyte. There was a, pp.ared no cell division activity. Spermatozoa in the seminiferous tuble was not noticed but degeneration of interstitial cell was started and spermatozoa in the epididymal duct disa, pp.ared. 3. Degeneration of oocyte and follicular cell was noticed as the histological change of ovary. There was not a, pp.arance of primary follicle and corpus Iuteum but interstitial cell was proliferated. 4. For the effect of adrenalectomy on the histological change of the thyroid gland, the number of small follicle decreased and that of large follicle increased as the time passed following the adrenalectomy. And the follicular epithelial cell became squamous as typical condition of functional decreased. 5. It was shown that in the total contents of serum protein no difference with control occurred with in the 70th day for male and female adrenalectomized, respectively. But the differences in protein contents were significanly decreased on the 70th day. 6. No difference occurred in the total serum lipids on the 7th day, but they decreased significantly on the 42nd day, and (P<0.01) on the 56th, and 70th day. A tendency to decrease was noted as time elapsed following adrenalectomy. 7. Increase and decrease were intercrossed in the serum cholesterol contents between the control and th treatment groups on the 28th day. But the difference significantly decreased on the 42nd, 56th, and 70th day after adrelalectomized. The contents showed tendency to decrease as time elapsed following adrenalectomy. 8. The blood glucose contents rapidly decreased with time. The difference were significant on the 28th and 42nd day, and highly significant on the 56th and 70th day for male adrenalectomized. 9. In case of solium, there was no noticeable sexual distinction. There was slight in creasing or decreasing for the control group. But the treatment group tended continuously to decrease for male and female. 10. It was shown that potassium contents tended to increase on the 28th day for male and female, but the differences were small. 11. As for chlorine, it tended to decrease rapidly on 7th day for male and female adrenalectomized, and the tendency continued.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.994-998
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• 1999

To evaluate the effects of sucrose-fatty acid ester (SE) on bread-making characteristics, the dough mixing, gelatinization, baking properties with the addition of SE alone and together with other surfactants were investigated. SE increased the peak time and the peak height in mixogram, indicating that it contributed the elasticity of dough. In farinogram, SE increased the peak time and mechanical tolerance index, but reduced the dough stability. SE increased the peak viscosity and reduced the gelatinization temperature and maximum consistency temperature in amylogram. SE increased the specific volume of bread loaf and retarded the increase in hardness of bread during storage, showing its anti-staling effects. The maximum anti-staling effect of SE was observed at 0.5% level. The addition of SE (0.2%), SSL (0.15%) and ES-95 (0.15%) blend showed the maximum specific loaf volume, and that of SE (0.25%) and SSL (0.25%) did the maximum anti-staling effect.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.365-374
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• 1999

To obtain informations on vertical movements of water and solute in rice paddy field during the growing season, soil water contents and bulk electrical conductivities (${\sigma}_a$) were monitored using Time Domain Reflectometry. Soil water contents with depth showed ${\varepsilon}$-shaped profiles constituting of partly saturated zones at top and bottom layers and unsaturated zones (20-100cm) between them. Analysis by fitting with a van Genuchten-type model showed that soil water contents at 60cm were affected by both water supplied from surface water and groundwater, but at 80cm mainly affected by groundwater. Water percolation at the rate of 2cm $day^{-1}$ rates were, but large fluctuation from 10 to 38cm $day^{-1}$ in C1 layer (60-90cm). Therefore, it can be said that any water or solute entering C1 layer is very rapidly transported to C2 layer, especially during the period of high groundwater table staying, and retarded to a relatively constant percolation rate in C2 layer. This can be manifested by the fact that rapid decrease and steady increase of electrical conductivities at 50 and 110cm depth respectively, were found around that period.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.29-42
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• 2001

The purpose of this study was 10 investigate the effect of jujube on the physicochemical properties of lnjeulmi during storage. Various lnjeulmi samples were prepared with steamed glutinous rice, glutinous rice flour, or brown glutinous rice flour along with the addition of chopped jujube at 3, 6, 9, or 12% of rice. In sensory evaluation, the more jujube was added, the stronger sweetness and bitterness were obtained. The samples made with steamed glutinous rice gave the harshest texture. Tenderness and moistness of Deachu-Injeulmi were the highest in the samples made with glutinous rice followed by brown glutinous rice flour, and glutinous rice flour, and they were increased with less amount of jujube. The chewiness of the samples made with brown glutinous rice flour' was the highest and the samples made with glutinous rice were the coarsest. The more jujube was added, the redness and yellowness of Daechu-Injeulmi were increased. The moisture content was higher in the samples made with glutinous rice followed by glutinous rice flour and brown glutinous rice flour. The reducing sugar content of samples during storage was higher in the order of glutinous rice, glutinous rice flour, and brown glutinous rice flour, and it was dramatically reduced until 48hr of storag e; however, it was increased a little bit after 72 hr. The degree of gelatinization was reduced rapidly during the first 24hr of storage, and it was decreased in the order of brown glutinous rice flour, glutinous rice flour, and glutinous rice. The springiness and cohesiveness were decreased during storage. The chewiness and gumminess were increased with the increase of added jujube, and they were increased until 24hr of storage, then decreased after 48hr. The hardness was the highest in the samples made with glutinous rice and 12% of chopped jujube showed the least change in the hardness. The more jujube was added, the less change in the hardness of samples was observed during storage, consequently retarded the speed of retrogradation