• Journal of Aquaculture
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• v.21 no.1
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• pp.41-46
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• 2008

The purpose of the study was to suggest the optimal lipid enrichment conditions used digestive enzyme activity of rotifer changing due to water temperature and salinity. The high population growth appeared at the experiment temperature more than 28 degrees highly on the culture temperature(maximum 32 degrees, 1,453 individual/mL). The fecundity was low at high temperature, and the egg ratio was high at low temperature. Population growth of 10 and 15 ppt appeared in most highly, but the fecundity and the egg ratio were high most significantly appeared in natural seawater(32 psu). The digestive enzyme activity by the culture environment mainly showed high activity in natural seawater(amylase exclusion, 15 psu). However, the TAP activity by the water temperature showed highly at the more high temperature, but the amylase and the lipase appeared at low temperature. We carried out the lipid enrichment at 20 degrees and 26 degrees in a condition of the natural seawater. Total protein, the total essential amino acids differed not significantly. The methionine content that was essential amino acids, a total lipid content, unsaturated index of fatty acids, DHA and the DHA/EPA ratio were high significantly each in $20^{\circ}C$ enrichment trial. Therefore, we could suggest the $20^{\circ}C$ and natural seawater for the optimal lipid enrichment condition in aquaculture, because methionine contents, several indexes by the lipid, TG-lipase activity, fecundity and egg ratio are high.

• Journal of Biosystems Engineering
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• v.30 no.1 s.108
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• pp.8-16
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• 2005

The extrusion-cooking condition on Cordyceps pruinosa was designed using twin-screw extruder. Response surface methodology (RSM) was used to investigate extrusion-cooking using a central composition design with varying die temperature $(114-146^{\circ}C)$, feed moisture $(22-38\%)$, feed rate (4-14 ka/h) and screw speed (120-280 rpm). System parameters (die pressure and specific mechanical energy (SME)) and extrudate parameters (density and water solubility index (WSI)) were statically analyzed using RSH. Die pressure was significantly affected by temperature, moisture contents and feed rate. SM was affected by screw speed and feed rate. When die temperature is $130^{\circ}C$ and moisture content $25\%$, the optimum pressure is shown. SME is about 20 Wh/kg, when feed rate is $10\~12kg/min$ and screw speed $200\~250rpm$. WSI was affected by temperature and moisture contents. Density was not affected by any factor. WSI increases by $7\%$ from about $23\%$ to about $30\%$, as temperature is raised from $120^{\circ}C\;to\;140^{\circ}C$. The WSI of Cordyceps pruinosa pulverized after extruding (PE) is about $26.97\%$ higher than that of raw material and $10\%$ higher than that of pulverized after drying (PD). The content of unsaturated fatty acid were not significantly different in PD and PE. Anti-oxidative activity of PE was 1.67-2.2 times higher than that of PD in Cordyceps pruinosa using 1- dipheny1-2-picrylhydrazyl method (DPPH).

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.338-351
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• 2005

Statement of problem. Accurate fit between the implant components is important because the misfit of the implant components results in frequent screw loosening, irreversible screw fracture, plaque accumulation, poor soft tissue reaction, and destruction of osseointegration. Purpose. This study is to evaluate the machining accuracy and consistency of the implant fixture/ abutment/screw interfaces of the internal connection system by using a Stereoscopic Zoom microscope and FE-SEM(field emission scanning electron microscope) Materials and methods. The implant systems selected in this study were internal connection type implants from AVANA(Osstem^{\circledR}), Bioplant(Cowell-Medi^{\circledR}), Dio(DIO^{\circledR}), Neoplant(Neobiotech 􀋓), Implantium(Dentium􀋓)systems. Each group was acquired 2 fixtures at random. Two piece type abutment and one piece type abutment for use with each implant system were acquired. Screw were respectively used to hold a two piece type abutment to a implant fixture. The implant fixtures were perpendiculary mounted in acrylic resin block. Each two piece abutment was secured to the implant fixture by screw and one piece abutment also secured to the implant fixture. Abutment/fixture assembly were mounted in liquid unsaturated polyester. All samples were cross-sectioned with grinder-polisher unit. Finally all specimens were analysed the fit between implant fixture/abutment/screw interfaces Results and conclusions. 1. Implant fixture/abutment/screw connection interfaces of internal connection systems made in Korea were in good condition. 2. The results of the above study showed that materials and mechanical properties and quality of milling differed depending on their manufacturing companies.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.73-86
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• 2010

The current study was designed to optimize solid phase microextraction (SPME)-GC-MS conditions for extraction and analysis of volatile components for Hanwoo beef and to establish a tentative database of flavor components. Samples were taken from Hanwoo longissimus muscle (30 mon old steer, $1^+B$ carcass grade) at 24 h postmortem. Results indicated that the optimum adsorption time for $75{\mu}m$ CAR/PDMS fiber was 60 min at $60^{\circ}C$. Thermal cleaning at $250^{\circ}C$ for 60 min was the best practice for decontamination of the fiber. A short analysis program with a sharp oven temperature ramp resulted in a better resolution and higher number of measurable volatile components. With these conditions, 96 volatile compounds were identified with little variation including 22 aldehydes, 8 ketones, 31 hydrocarbons, 12 alcohols, 8 nitrogen- and sulfurcontaining compounds, 5 pyrazines and 10 furans. A noticeable observation was the high number of hydrocarbons, aldehydes, ketones, alcohols and 2-alkylfurans which were generated from lipid decomposition especially the oxidation and degradation of unsaturated and saturate fatty acids. This implies that these compounds can be candidates for flavor specification of highly marbled beef such as Hanwoo flavor.

• The Journal of Engineering Geology
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• v.19 no.2
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• pp.205-215
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• 2009

The conventional numerical models to analyze flow in subsurface porous media under the transient state usually generate numerical oscillation and unstability due to local flux domain for critical cases such as infiltration into initially dry soil during rainfall period. In this case, it is required refined mesh and small time step, but it decrease efficiency of computation. In this study, numerical unstability in discontinuity domain is removed by applying particle tracking algorithm to simulate unsteady subsurface flow with inflow boundary condition. Finally the hybrid LE FEM improving numerical stability is proposed. The hypothetical domains with unsteady uniform and nonuniform flow field were used to demonstrated algorithm verification. In comparison with analytic solution, we obtained reasonable results and conducted simulation of hypothetical 3-D recharge/pumping area. The proposed algorithm can simulate saturated/unsaturated porous media with more practical problems and will greatly contribute to accuracy and stability of numerical computation.

• Korean Journal of Food Science and Technology
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• v.5 no.1
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• pp.36-41
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• 1973

Chemical changes with time of frying-fats during the frying process (beef tallow with 0.01% BHA and 0.01% BHT, turnover rate 9%/hr and $140{\pm}10^{\circ}C$ temperature) of Ramyon on a commercial scale were studied. No significant changes of carbonyl value and peroxide value were noted up to 120 hrs. However, small increases in acid value, color and dimeric fatty acid were noted. Small decreases in iodine value and the content of unsaturated fatty acids were also observed. Under the experimental storage condition, when the stability of fats heated were compared to fresh fat, minor differences in carbonyl value and weight gain were noted. All of these demonstrated that frying-fats commercially used in Ramyon frying system were maintained in good quality during the frying process.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.75-81
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• 1998

The yeast strain 504D, isolated from salted shrimp soup, showed the best proteolytic activity under alkaline condition. The yeast formed vegetative cells in almost optimal media for yeasts, but formed only pseudohyphae in the MM medium containing citric acid and true hyphae in the MM medium containing N-acetylglucosamin and ${\beta}$-D-glucose. The yeast was classified as hemiascomycetes to form ascospores by sexual reproduction, and formed blastospores and athrospores by asexual reproduction. The yeast strain did not assimilate almost of the carbon sources, nitrate and nitrite, but some organic acids and alcohols. The fatty acids of whole cells were composed of 53.67% unsaturated fatty acids and 14.58% saturated, and, especially, C17:1 was observed in this strain but not in two control yeasts. However, almost of all results were very similar to the morphological and physiological characteristics of Yarrowia lipolytica KCCM 12495 and KCCM 35426, except for a little differences which are the composition of fatty acids and the manner of mycellium formation. Therefore, the isolated yeast strain 504D is identified as a Yarrowia lipolytica.

• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.27-34
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• 2011

This study analyzes the determination of slope failure model due to changes in ground condition followed by heavy rainfall. With a simulated rainfall system, the movement of a slope from the rainfall penetrating the unsaturated soil is investigated with respect to various conditions of pore-water pressure, earth pressure, and moisture content, considering rainfall duration and permeability. As a result of the experiment, under the persistent precipitation of 50mm/h, pore-water pressure of weathered granite soil started increasing from the upper position of the slope, and then the pressure increased in middle and bottom portion of it in timely manner. In case of the pore-water pressure of the standard soil, the pressure increased from the middle and bottom portion, and the cause of the different order is suspected to be the difference in permeability between the standard soil and the weathered granite soil. As an outcome, though the result may vary by each foundation, there exists a danger of slope failure not only when the cumulative rainfall is more than 120 mm but also when the saturation level amounts to 60~75%.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.1 s.12
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• pp.25-31
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• 2004

Infiltration of rainfall causes railway embankment to be unstable and may result in failure. Basic relationship between the rainfall and stability of railway embankment is defined to analyze the stability of embankment by rainfall. An experimental study for defining of infiltration rate of rainfall into slope is conducted in the lab. The results of Rainfall Infiltration show that rainfall Infiltration is not equal to infiltration as like reservoir because rate of rainfall infiltration is controlled by slope angle. Based on these results, boundary condition of rainfall is altered and various numerical analysis are performed. The variation of shear strength, the degree of saturation and pore-water pressure for railway slope during rainfall can be predicted and the safety factor of railway slope can be expressed as the function of rainfall amount, namely rainfall index. Therefore, it is judged that this rainfall index can be a good tool for the rail-transport operation control.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1110-1117
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• 2001

Responses of the rumen fungus, Neocallimastix frontalis RE1, to long chain fatty acid (LCFA) were evaluated by measuring gas production, filter paper (FP) cellulose digestion and polysaccharidase enzyme activities. LCFA (stearic acid, $C_{18:0}$; oleic acid, $C_{18:1}$; linoleic acid, $C_{18:2}$ and linolenic acid, $C_{18:3}$) were emulsitied by ultrasonication under anaerobic condition, and added to the medium. When N frontalis RE1 was grown in culture with stearic, oleic and linoleic acid, the cumulative gas production, gas pool size, FP cellulose digestion and enzymes activities significantly (p<0.05) increased at some incubation times(especially, exponential phases of fungal growth, 48~120 h of incubation) relative to that for control cultures. However, the addition of linolenic acid strongly inhibited all of the investigated parameters up to 120 h incubation, but not after 168 and 216 h of incubation. These results indicated that stearic, oleic and linoleic acids tended to have great stimulatory effects on fungal cellulolysis, whereas linolenic acid caused a significant (p<0.05) inhibitory effects on the cellulolysis by the rumen fungus. These results are the first report of the effect of LCFAs on the ruminal fungi. Further research is needed to identify the mode of action of LCFAs on fungal strains and to verify whether or not ruminal fungi have ability to hydrate unsaturated LCFAs to saturated FAs. There was high correlation between cumulative in vitro gas production and fungal growth (94.78%), FP cellulose degradation (96.34%), CMCase activity(90.86%) or xylanase activity (87.67%). Thus measuring of cumulative gas production could be a useful tool for evaluating fungal growth and/or enzyme production by ruminal fungi.