• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.56-62
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• 1979

Boring the process of curing of the tobacco ( Nicotiana tabacum L. clicks) leaf, the and other fundamental components of the tobacco leaf was observed The amount of total chlorophyll was reduced from 2902$\mu\textrm{g}$/gr to 1, 131$\mu\textrm{g}$/gr as a function of curing time. In the case of total carotene, the concentration was increased from 373-712$\mu\textrm{g}$/gr. to 3, 003~2, 215$\mu\textrm{g}$/gr. up to 70 hours of curing period. However, after 70 hours of curing, the concentration of total carotene stared to be decreased up to 1, 050~1, 039$\mu\textrm{g}$/gr. Simultaneously, the greenish yellow color becomes to be close an intermediate color between yellow and orange. The amount of total nicotine and nitrogen (2~2%) in the green harvested leaf was essentially identical after the curing process. However, the amount of total sugar was enhanced from 17%, in the green harvested leaf, to 35% at the time of 70 hours curing. At the end of the curing, the amount of total sugar was again reduced up to 16%. The correlation coefficient (r) between the axis of the color coordinate and the ratio of chlorophyll/carotene was estimated to be r=-0.96. This result indicates a linear relationship between those two parameters and the following linear equation is obtained as y=28.87-68.38 x. From the above equation, x=0.442 could be estimated when chlorophyll was completely decomposed (ylongrightarrowO). As a consequence of this result, we can suggest the tobacco leaf of Hicks belongs to the high quality level.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.95-100
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• 2004

The main objectives of the study were to investigate cultural characteristics of Phellinus linteus. The optimum culture media for mycelial growth of P. linteus were MYA (malt yeast agar) and SMS (soybean powder malt Sucrose). Similarly, optimum temperature and pH were $30^{\circ}C$ and 6.0, respectively. Malt extract (2%, v/v) and yeast extract (0.2%, v/v) were optimum carbon and nitrogen sources. Similarly, 0.1% $KH_2PO_4$ was optimum mineral salt. Highest mycelial growth was observed when C/N ratio was 10 : 1. Optimum inoculum amount for flask culture was $5{\sim}6$ mycelial discs (6 mm diameter) per 100 ml of liquid medium, Highest mycelial dry weight was obtained when cultured in 100 ml liquid medium in 300 ml shaking flask after 20 days of shaking culture, For mass liquid culture (8 l), flask culture was homogenized and used as an inoculum. Optimum culture period and aeration rate for 8l fermentation culture were 12 days and 2.0 vvm, respectively.

• Journal of Aquaculture
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• v.15 no.1
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• pp.15-21
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• 2002

Two groups of juvenile flounders (90 g/each) were fed on moist pellet feed thrice a day for a period of 8 weeks; the first group, reared in 4 circular (6m $\times$ 0.8 m) tanks (1200 flounders/tank), was fed daily (ED) and the second one on alternate days (EO). There was no significant difference in growth and feed conversion ratio (FCR) between these groups. There was also no difference in chemical composition, except in lipid, which was significantly higher (4.1%) in the ED group than the EO group (3.4%). Food intake and gain in the whole body nitrogen (N) were higher in the ED group but there was no significant difference between these groups in N retention; they excreted almost equal amount (114 vs 112 g) of N. Although phosphorus intake was significantly different between these groups, the flounders retained equal amount (0.5 g) of P in their body and excreted also equal amount (27.6 vs 26.0 g/kg weight gain) of p. Energy intake (2528 kJ) of the ED group was higher than that (2116 kJ) of the EO group. However, there was no significant difference in their energy retention efficiency. Clearly, alternate day feeding regimen led to more efficient utilization of food by the juvenile flounder.

• The Korean Journal of Mycology
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• v.15 no.1
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• pp.42-47
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• 1987

4 strains of the oak mushroom Lentinus edodes including the strain ASI 3046 were collected home and abroad to investigate the characterics of mycelial growth on synthetic media and sawdust media. The possibility of artificial culture of Lentinus edodes on media composed of different saw dusts and adding materials was investigated. Results were as follows: The optimum temperature for growth ranged from $22^{\circ}C$ to $26^{\circ}C$ among the lineages of Lentinus edodes. The optimal growth temperature for ASI 3046 strain and ASI 3047 strain was $26^{\circ}C$ and $22^{\circ}C$, respectively. The optimal carbon source for ASI 3046 strain was glucose, and peptone and ammoinum tartrate were proved excellent as nitrogen sources. When Lentinus edodes was cultured on sawdust media by varying the mixing ratio of different sawdusts and adding materials, mixed sawdust media composed of oak sawdust(50%, v/v), poplar sawdust(50%, v/v), acorn powder(5%, v/v) and rice bran(10%, v/v) showed higher yields of fruit bodies. Results showed that the ideal strain of Lentinus edodes for artificial culture on sawdust media was strain ASI 3046.

• Ocean and Polar Research
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• v.27 no.3
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• pp.251-263
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• 2005

In order to study changes in the marine ecosystem of the East China Sea derived by the global warming and construction of the Three Gorges Dam in the middle of the Changjiang, temperature, salinity, nutrients, and chlorophyll-a were studied intensively in the northern part of the East China Sea during the summer of 2003 and spring of 2004. According to the previous studies, the upwelling of the Kuroshio Current and the Changjiang resulted in a major inputs of nutrients in the East China Sea, but these two inputs may not contribute gently to a build up of nutrients in the northern East China Sea. In spring, relatively high concentrations of nitrates and phosphates were observed in the western part of the study area, which resulted from the supply of high concentrations of nutrients showing up in the surface waters as a result of vertical mixing from the ocean bottom. The concentrations of nitrates and phosphates observed in summer were lower than those in spring, since the surface waters were well stratified by the larger discharge of fresh water from the Changjiang in summer. The surface nitrate/phosphate ratios ranged from 1.3 to 16 in spring and from 1.1 to 15 in summer and were lower than the Redfield ratio of 16, indicating that the growth of phytoplankton is limited by nitrogen. This results are contrary to the previous results, in which the growth of phytoplankton was limited by phosphate in the East China Sea. The reason for this contrary result is that most nutrients in the surface waters are supplied by vertical mixing from the bottom waters with low nitrate/phosphate ratios, not directly influenced by the Changjiang with high nitrate/phosphate ratios. The depth-integrated chlorophyll observed in summer was similar to the previous results, but those measured in spring were almost twice as high as those found in previous results. The depth-integrated chlorophyll in spring was higher than that of summer, which results from high concentrations of nitrates and phosphates in the surface waters in spring due to active vertical mixing.

• Korean Journal of Environmental Biology
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• v.22
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• pp.93-102
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• 2004

A total of 110 surface sediment were analyzed in order to understand the geochemical eharacteristics of the surface sediments and to evaluate the benthic environmental condition of Gwangyang Bay. The surface sedimentary distribution can be classified by five facies; mud (M), sandy mud (sM), sand (S), muddy sand (mS) and gravely sand mud ((g)sM). However, mud face is the predominant sedimentary feature of the Gwangyang Bay. The benthic environment based on total organic carbon/total nitrogen (C/N) and total organic carbon/total sulfur (C/S) ratios of organic matter showed that anoxic environment is prevailed in some parts of the study area because the C/S ratio of organic matter was higher than 2.8. The hydrogen sulfide (H$_2$S) content showed extreme variability from site to site. It varies from 307 ppm to 1 ppm (average, 92 ppm). The inter-relationship of redox-sensitive elements (Mn, V, Mo and Cr) showed a relatively strong positive relationship with high accumulation in the sediment at the inner sites of the Bay (left of Myo Island). High content of TOC and hydrogen sulfide, and a high accumulation rate of redox- sensitive element were predominant characteristics in the sediments at the inner sites of the Bay (left of Myo Island), suggesting that this area is in an oxygen deficient, and potentially polluted condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.660-666
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• 1997

Changes of chemical and nutritional composition were investigated in low salt-dried Yellow corvenia muscle during frozen storage at $-20^{\circ}C$. Moisture contort of Yellow corvenia was not significantly changed until after 5 months frozen storage. Salinity was $0.28\%$ in fresh Yellow corvenia and $2.30\%$ in the salted sample. Acidity of the fish muscle was increased in excess of 5 months storage. TBA value was increased by a little amount untel 1 month of storage and significantly incraeased in 3 months of storage. Free fatty acid was increased during frozen storage with rapid increase up to 1 month storage. VBN was increased after 1month storage and amino type nitrogen was increased in 5 months of storage. Major free amino acids were glutamic acid, alanine, glycine and lysine, and composition ratio of most free amino acids were not changed untel after 5 months storage. Polyenoic acid contents were decreased after storage and major fatty acids were palmitic acid (16 : 0), stearic arid (18 : 0) and major fatty acids were palmitic acid (16 : 0), stearic acid (18 : 0) and docosahexaenoic acid (22 : 6). From the results of chemical experiments, low salt-dried yellow corvenia would not be stored at $20^{\circ}C$ for more than 5 months.

• Journal of Nutrition and Health
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• v.18 no.3
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• pp.201-208
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• 1985

The purpose of this study was to estimate the sodium and potassium intakes of university students in Korea and to evaluate the relationship between blood pressure and related variables. Two hundred and eighty five subjects were selected from among healthy university students aged 17 to 28. The urinary (sodium, potassium urea nitrogen and creatinine) excretions in 24 hrs. were evaluated from the analysis of urine samples gathered for 12hrs. At the same time, dietary intakes of sodium and potassium were assessed by the modified convenient method with the same subjects. The results were as follows : 1) The urinary sodium excretions of male and female students in 24hrs. were estimated at 199.1mEq and 174.5mEq respectively. Daily sodium intakes by the questionnaire were calculated to be 218.5mEq for male students and 218.1mEq for female students. 2) The urinary potassium excretions in male and female students were 48.3mEq/24hr and 43.9mEq/24hr. respectively, and the potassium intakes 48.6mEq/24hr. and 47.4mEq/24h. each 3) No correlations were found between blood pressure and the urinary excretions of sodium potassium or urinary Na/K ratio in college students.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.18 no.1_2
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• pp.21-25
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• 2012

This study was conducted to investigate the effects of filling and packaging temperatures on the quality changes of retorted Samgyetang during storage. The samples were manufactured after filling the broth maintained either at $50^{\circ}C$ (T1) or $85^{\circ}C$ (T2) into pouch and followed by sterilizing them at $120^{\circ}C$ for 65 min under the F value of approximately 8.0. The samples were stored at $25^{\circ}C$ up until 6 months and various physic-chemical parameters including pH, oxygen ratio in the headspace of package, residual dissolved oxygen concentration in the broth, acid value, volatile basic nitrogen value (VBN), apparent viscosity, spreadability of porridge, and sensory attributes were analyzed periodically at month 0, 1, 3, and 6, respectively. During storage time, the dissolved oxygen concentration and acid values of T2 samples tended to increase slower than T1 (p<0.05). Between T1, and T2 samples, significant differences were observed for pH and dissolved oxygen concentration over the storage period while acid values and VBN values were significantly different from 3 months (p>0.05). Contrarily, no apparent differences were observed between two samples in the apparent viscosity, spreadability of porridge, and sensory attributes over the storage period (p>0.05).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.649-657
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• 2017

A rupture in a high-pressure pipe causes the fluid in the pipe to be discharged in the atmosphere at a high speed resulting in a supersonic jet that generates the compressible flow. This supersonic jet may display complicated and unsteady behavior in general. In this study, Computational Fluid Dynamics (CFD) analysis was performed to investigate the compressible flow generated by a supersonic jet ejected from a high-pressure pipe. A Shear Stress Transport (SST) turbulence model was selected to analyze the unsteady nature of the flow, which depends upon the various gases as well as the diameter of the pipe. In the CFD analysis, the basic boundary conditions were assumed to be as follows: pipe of diameter 10 cm, jet pressure ratio of 5, and an inlet gas temperature of 300 K. During the analysis, the behavior of the shockwave generated by a supersonic jet was observed and it was found that the blast wave was generated indirectly. The pressure wave characteristics of hydrogen gas, which possesses the smallest molecular mass, showed the shortest distance to the safety zone. There were no significant difference observed for nitrogen gas, air, and oxygen gas, which have similar molecular mass. In addition, an increase in the diameter of the pipe resulted in the ejected impact caused by the increased flow rate to become larger and the zone of jet influence to extend further.