• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.33-45
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• 1997

Axisymmetric shear layers around a free jet is forced by co-flowing and counter-flowing secondary jets from/to an annular tube around the jet nozzle. The jet potential core extends far downstream with co-flowing secondary jets due to inhibited vortex developing and pairing. For counter-flowing cases, the axisymmetric shear layer around the jet transits from convective instability to absolute instability for velocity ratios R＝1.3～l.65 for the uniform velocity jets. Consequently, the jet potential core length increases and the turbulence level in the jet core is reduced significantly. The jets are controlled better with extension collars attached to the outer nozzle exit because the annular secondary flow is guided well by the extension collars. For the vectoring of jet, the annular tube around the jet is divided in two parts and the only one part is used for suction. The half suction makes the different shear layer around the jet and vectoring the jet by Coanda effect. The vectoring and turbulent components are varied significantly by the suction ratio. The experiments are carried out to investigate the characteristics of forced free jets using flow visualization, velocity and turbulence measurements.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2003.06a
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• pp.95-117
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• 2003

본 연구는 한우육의 육질등급과 저장기간에 따른 육질 및 저장특성과 맛성분의 차이를 조사하고자 실시하였으며, 도축 24시간 후 도체등급판정을 실시한 한우 36두의 등심부위를 시료로 취하여 $2^{\circ}C$ 냉장실에서 14일간 저장하면서 이화학적 특성 및 관능적 특성을 조사하였다. 그 결과를 요약하면 다음과 같다. 육질등급에 따른 도체 특성에 있어서 등급간의 지방두께, 배최장근 단면적 및 육량등급은 차이가 없었으며, 육색과 지방색, 성숙도 등도 차이가 없는 것으로 나타났으나 조직감은 1등급육이 3등급육에 비하여 좋은 것으로 나타났다. 1등급육은 3등급육에 비하여 지방함량(9.87${\pm}$2.23%)이 높았으며, 수분함량(67.75${\pm}$l.63%)이 낮았으나(p<0.05), 단백질함량은 육질등급간에 차이가 없었다. 도축 24시간후의 L, b, h-값은 등급간에 차이가 없었으며, a와 C-값은 2등급육이 다른 등급에 비하여 다소 높게 나타났다. L, a, b-값 모두 저장기간이 경과함에 따라 다소 증가하였다. pH는 육질등급간에 차이가 없었으며 저장기간에 따른 차이도 없었다. 1등급육은 3등급육에 비하여 드립감량은 다소 낮은 것으로 나타났으며, 가열감량은 등급간에 유의적인 차이는 없었으나 1등급육이 가장 적은 가열감량을 나타냈다. 보수력은 1등급육이 2, 3등급육에 비하여 유의적으로 높았으며, 근절길이와 콜라겐 함량은 등급간에 차이가 없었다. 전단력값은 3등급육이 1, 2등급육에 비하여 다소 높은 전단력값을 보였으나 유의적인 차이는 없으며, 근원섬유 소편화도는 등급간에 차이가 없었다. 저장기간이 경과합에 따라 전단력값은 점차적으로 낮아졌고 근원섬유 소편화도는 유의적으로 증가하였다. 1등급육이 2, 3등급육에 비하여 TBA가가 높았고, VBN함량은 낮았으나 유의적인 차이는 없었으며, 저장기간이 경과함에 따라 TBA가와 VBN함량은 증가하였다. 관능평가에서 풍미는 육질 등급간에 차이가 없었으나, 연도, 다즙성 및 전체적인 기호도는 1등급육이 3등급육에 비하여 다소 우수한 것으로 나타났다.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.826-831
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• 1989

The rheological properties of concentrated Kochujang (Korean red pepper paste)-water suspensions were investigated. The rheological behavior of Kochujang-water suspension was illustrated by Herschel-Bulkley equation. All Kochujang-water suspensions with 12.5-100% of water addition showed pseudoplasticity in yield stress at the shear rate range of $0.25-179.20sec^{-1}$., but at the shear rate above $5.16 sec^{-1}$, more shear thinning behavior was observed with increasing shear rate. Also, pseudoplasticity of the suspension became weak by increasing water addition and decreasing temperature, The temperature dependence of consistency index on Kochujang-suspension was very low and the values of consistency index was lowered by increasing solid contents, but as heating, the values of that was increased. It was suggested that the main components responsible for rheological behavior of the suspensions at high temperature might be undigested starch or protein in Kochujang. Also, the changes of rheological behavior with vinegar addtion was only due to dilution effect.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.247-254
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• 2003

While the interests in the environmental problem during the construction are increasing, the use of low noise-vibration auger-drilled pilling is increasing to solve noise and vibration problem in pilling. Therefore, in Korea, SIP (Soil-Cement Injected Precast Pile) method is mainly used as auger-drilled pilling. However, there is no proper design criteria compatible with the ground condition of Korea, so which is most wanted. To improve and supplement this situation, direct shear tests for the friction between SIP pile skin interface and soil were executed on various conditions. Through the analysis of test results, skin friction characteristics of SIP were investigated thoroughly Also, hyperbolic model parameter fomulas which describe the friction behavior and the new non-linear unit skin friction capacity model with SM, SC soil were suggested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.637-642
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• 1996

This study was carried out to investigate the change of palatability improvement of cooked meat by the physico-chemical properties and sensory characteristics as aging at $3^{\circ}C$ after thawing of frozen Holstein tenderloin. Shear force value(SFV), myofibrillar fragmentation ratio(MFR), appearance of 30ki1o dalton (30KD) component, raw meat aroma, tenderness, palatability of cooked meat, content of free amino acid and ATP related compound were measured. Raw meat aroma (p< 0.01), tenderness(p<0.05), SFV(p<0.05), MFR(p<0.01) and 30KD(p<0.001) of unfrozen beef tenderloin aged at $3^{\circ}C$ were superior than frozen beef tenderloin. As aging at $3^{\circ}C$ after thawing of frozen beef tenderloin SFV(p<0.05) decreased, MFR(P<0.001) and 30KD(p<0.001) increased, and raw meat aroma and tenderness improved(p<0.05). Also, cooked meat aroma, texture and palatability improved(p<0.05), without changing the taste. The content of aspartic acid and leucine of tenderloin aged thawing of frozen beef abounded were more than frozen beef(p<0.05), concentration of IMP(P<0.05) decreased, the hypoxanthine(p<0.05) and inosine increased.

• The Journal of the Petrological Society of Korea
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• v.10 no.1
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• pp.36-55
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• 2001

Hornblende geobarometry has been applied to estimate the emplacement depth of the Jurassic Yeongiu, Andong, and Gimcheon granites in the Yeongnam Massif. Geobarometry was determined from the twenty two samples of the Yeongiu granite, ten samples of the Andong granite and twelve samples of the Gimcheon granite, using the composition of hornblende rims coexisting with the mineral assemblage required for pressure determination. Amphibole compositions in the three granites vary from edenite to ferropargasite with the increase of pressure. According to the equation of Schmidt(1992), the pressures of emplacement of the Yeongiu, Andong, and Gimcheon granites are 5.6 to 7.9 kb, 5.5 to 7.5 kb, and 4.1 kb to 5.3 kb, respectively. The emplacement depth in the Yeongiu granites increase systematically from about 6 kb in the northwest to about 7.5 kb in the southeast. Andong granite shows no systematic change of the pressure estimates. The Gimcheon granite shows almost consistent pressure distribution. The pressure difference of about 1.5 kb across the Yeongiu granite may be explained by a model combining late postemplacement upsurge of a deeper part of the pluton in the south with tilting of the batholith by Yecheon shear zone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.362-366
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• 2008

This study was carried to investigate effects of gamma irradiation on the moisture, crude protein, crude lipid, 2-thiobarbituric acid (TBA) values, color stability, texture, and sensory properties of restructured pork jerky. Restructured pork jerky was irradiated at dose levels of 0, 3, 5, 7 and 10 kGy with a use Co-60 source. There were no significant differences in the moisture, crude protein, crude lipid contents, and TBA values. However, as doses of gamma irradiation increased, the redness (a-value) of restructure pork jerky increased whereas shear force of restructure pork jerky was decreased by gamma irradiation. Sensory evaluation showed that sensory scores were reduced by gamma irradiation. Therefore, gamma irradiation could be an effective means to improve color and texture of restructured pork jerky, but only with proper consideration for sensory quality.

• Geotechnical Engineering
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• v.12 no.6
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• pp.115-126
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• 1996

The purpose of 1,his study is to analyze the compression and strength charactefistics of the decomposed -weathered soil originating from biotite gneiss or fine grained gneiss sampled from Poidong, Seoul : to figure out the behavioural characteristics of the decomposed -weathered soil in accordance with mineral composition and origin by comparing experimental results of residual soils. originating from granites and sampled from Bulam, Andong and Kimchun area. A series of CIU, CID CKoV, CKoD tests were car lied out. Although weathered soils have different origin and mineral composition, the slope of the NCL A was similar. It was also shown that plastic strain ratio was about 85% mainly due to the particle crushing effect during compression. The Poidong soil showed strain softening phenomenon unlike the Kimchun and Andong soils. this implies that the behavioural characteristics are affected by the origin and the mineral composition of the soil particles. Moreover, it was found that the angle of the shear resistance$(\phi')$ was dependent on the mineral composition. On the oher hand, measured Af values of decomposed weathered soils were more than one regardless of the origin and the mineral composition.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.747-752
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• 1993

A curd yogurt was prepared from milk added with skim milk powder or four kinds of starch such as rice starch, wheat starch, corn starch and potato starch. The effects of starch addition at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effects of starch addition on quality of curd yogurt in terms of apparent viscosity, sensory property and volatile aroma compounds were also examined. Addition of starch markedly stimulated the acid production by lactic acid bacteria. Among four organisms tested, Lactobacillus jugurti produced the highest amount of acid. Apparent viscosity of curd yogurt added with starch was significantly higher than that of control. Curd yogurt fermented with L. jugurti showed pseudoplastic and thixotropic characteristics. Sensory property of curd yogurt added with corn starch or rice starch was evaluated as slightly better than reference sample, but that with potato starch was evaluated as the worst among all samples. Acetaldehyde, acetone, ethanol and butanol were detected by gas chromatographic analysis.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.93-116
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• 2005

SPT-Uphole tomography method was introducedand verified in this paper. In SPT-Uphole method, SPT (Standard Penetration Test) which is common in site investigation, was used as a source and several surface geophones in line were used as receivers. Shear wave velocity (Vs) distribution map which has triangular shape around the boring point can be obtained by tomography inversion. The factors for obtaining reliable result of SPT-Uphole tomography are exact travel time information and accurate inversion method. To establish of the SPT-Uphole tomography procedure, the most reliable method for obtaining exact travel time information and verification of tomography inversion method were studied by using theoretical travel time information and finite element method (FEM) analysis. finally, SPT-Uphole tomography method was performed at the weathered soil site in Kimje. By comparing with several boring data including SPT-N value, feasibility of this method was verified in the field.