• 대한조선학회논문집
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• 제46권6호
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• pp.611-621
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• 2009

This paper first reviews the physical meanings and the expressions of two representative strain rate models: CSM (Cowper-Symonds Model) and JCM (Johnson-Cook Model). Since it is known that the CSM and the JCM are suitable for low-intermediate and intermediate-high rate ranges, many studies regarding marine accidents such as ship collision/grounding and explosion in FPSO have employed the CSM. A formula to predict the material constant of the CSM is introduced from literature survey. Numerical simulations with two different material constitutive equations, classical metal plasticity model based on von Mises yield function and micromechanical porous plasticity model based on Gurson yield function, have been carried out for the stiffened plates under impact loading. Simulation results coincide with experimental results better when using the porous plasticity model.

• 한국식품과학회지
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• 제28권4호
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• pp.673-677
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• 1996

지방과 재고미의 함량 변화에 따른 분쇄 우육의 pH 차이는 거의 없었으며 재고미의 첨가량이 5에서 20%로 증가할수록 가열후 수율도 증가하였다. 10% 지방 우육과 30% 지방 우육의 콜레스테롤 함량은 비슷한 수준이었으며 10% 지방육의 경우 재고미의 첨가량이 증가할수록 제품의 콜레스테롤 함량은 감소하였다. 분쇄 우육의 지방 함량을 30%에서 10%로 줄였을 때 열량은 50% 정도 감소하였고 육 100 g당 생산원가는 재고미를 5, 10, 20% 첨가하였을 때 각각 4.9, 9.9, 19.8%의 비율로 절감되었다. 결론적으로 분쇄 우육의 지방 함량을 30에서 10%로 줄이고 대신 재고미를 첨가하면 가열 수율은 높아지고 열량과 생산 원가는 절감되며 10% 지방육의 경우 재고미의 함량이 증가할수록 콜레스테롤 함량은 감소하는 유익한 효과가 확인되었다.

• Advances in nano research
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• 제17권1호
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• pp.33-49
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• 2024

Using the mechanical treatments for mechanical properties improvement was rarely in the development scope before. This research approves through analytical ways that surface impacts can improve the quality of the surface significantly. This fact is approved for deposited titanium on silicone substrate. The new algorithm called minimum resultant error method (MREM) which is a direct combination of nanoindentation, FEM and dimensional analysis through a reverse method is utilized to extract the mechanical characteristics of the coating surface before and after impact. This method is extended to the time dependent behavior of the material to obtain strain rate coefficient. To implement this new approach, a new analysis technic is developed to define the residual stress field caused by surface impact as initial condition for nanoindentation. Analyzing the model in micro and macro scale at the same time was one of the main resolved challenges in this study. The result was obtaining of the constants of Johnson-Cook constitutive equation. Comparing the characteristics of the coating surface before and after impact shows high improvement in yield stress (34%), Elastic modulus (7.75%) and strain hardening coefficient (2.8%). The main achievement is that the strength improvement in titanium thin layer is much higher than bulk titanium. The yield strength shows 41.7% improvement for coated titanium comparing with 24% for bulk material. The rate of enhancement is about 6 times when it comes to the Young's modulus.

• 한국축산식품학회지
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• 제39권6호
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• pp.863-876
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• 2019

The thermal-death times of Listeria monocytogenes were determined in inoculated restructured goat steak at 60℃, 65℃, and 70℃ of sous-vide temperatures. D-values of L. monocytogenes in inoculated restructured goat steak ranged from 7.27 min at 60℃ to 0.46 min at 70℃. Times need to yield at least a 6 log reduction of L. monocytogenes at their temperatures for this product were 47, 12, and 3 min, respectively. After sous-vide, all microbial counts in non-inoculated samples were not detectable, except the aerobic and anaerobic mesophilie and lactic acid bacteria counts were lower than 2 Log CFU/g. For sous-vided and grilled sous-vided samples, sous-vide loss and surface shrinkage were the lowest in samples sous-vided at 60℃ for 47 min (p<0.05). These samples demonstrated the lowest CIE L^*, shear force, hardness, gumminess and chewiness and the highest CIE a^* and hue angle (p<0.05). Therefore, sous-vide at 60℃ for 47 min provided convenient ready-to-cook restructured goat steak for microbiology safety and optimization of physicochemical quality.

• 펄프종이기술
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• 제33권3호
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• pp.75-83
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• 2001

The potential of oxygen delignification is a powerful tool to reduce detrimental environmental effects. This study was performed to investigate the effect of steam explosion treatment of chemically treated oak wood on oxygen-alkali pulping. Pulp yield during steam explosion treatment by ${Na_2}{O_3}$-NaOH impregnation was higher than the other impregnation chemicals. Also, NaOH extraction at room temperature after steam explosion treatment improved the kappa number from 140~116 to 90~64. Oxygen-alkali pulping of chemical steam explosion treated woods affected to pulp yields. ${Na_2}{O_3}$-NaOH impregnation was very effective to higher carbohydrate yields at same delignification level. Its carbohydrate yield seemed to be highly related to the effluent pH. Oxygen-alkali pulping after steam explosion treatment of ${Na_2}{O_3}$-NaOH impregnated wood was shown that carbohydrate yield was very high because its effluent pH was increase from natural to mild alkali. Even if oxygen bleaching limit the delignification to 50% in order to avoid unacceptable yield and viscosity losses, oxygen-alkali pulping after steam explosion by ${Na_2}{O_3}$-NaOH impregnation was possible to extend the delignification more than 80%. Considering high pulp yield with lower lignin content from steam explosion treated wood, it might be profitable to end the cook at a high kappa number instead of a low kappa number, and continuously apply the oxygen delignification, in order to better quality pulp.

• 한국잠사곤충학회지
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• 제17권1호
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• pp.1-26
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• 1975

These studies were attempted to find out the optimum silk reeling system by use of automatic silk reeling machine to increase raw silk yield and reeling efficiency with various silk reelable cocoons. The obtained results are as follows; 1. The mean silk reelability ratio(X)of the Korean cocoons during the last ten years was 61 per cent, beside 64.7 per cent in autumn cocoon and 57.3 per cent in spring cocoon. However, the ratio variation of autumn cocoons was larger than that of spring cocoons. 2. A positive correlation between cocoon filament breaks during its process and silk reelability levels was shown to be significant. The cocoons of both poor and good reelability evidenced "J" shape distribution on the filament break graph by the order of reeling cocoon end. Many bave breaks were found at the inner shell of the cocoons, or in case of poor reelability cocoons. 3. The morphology of broken cocoon ends during the process was classified into A, B, C, D, E and F types, The occurrence of B type was majority, but that of F type was minority among them. 4. In case of the cocoon cooking, H-type ion-exchanged soft water was better for good reelability cocoons, Na and H-type ion exchanged neutral soft water for those of fair reelability, and alkaline (Na-type) soft water for those of poor reelability, respectively. 5. The modification of cooking water by mixing the above different types of water (50％ Na-type and 50％ H-type passed by standard natural water; 75％ Na-type and 25％ H-type passed by hard natural water; 25％ Na-type and 75％ H-type passed by soluble natural water) made higher yield of raw silk with tess breaks of thread. 6, In case cocoon ends groping water included sodium hexametaphosphate as much as 800 ppm. the groping efficiency and raw silk yield of cocoon was improved. The effect was pronounced in case of poor reelability cordons. 7. The most reasonable cocoon cooking and silk reeling condition for automatic silk reeling process were observed to be rather incomplete cook with good reelability cocoons and optimum cook with poor reelability cocoons succeeded by the reeling bath temperature of 45$^{\circ}C$, 8. The reasonable silk reeling velocities were observed to be about 150m per min. for good reelability cocoons, 120m per min. for fair reelability ones and 90 to 120m per min. for poor reelability ones. 9. In order to improve the raw silk yield of cocoons and reeling efficiency, the cocoon stand-by-ratio for reeling should be kept at the level of 40 per cent for good reelability cocoons or at 60 per cent for poor reelability ones beside necessary end found cocoon condition.

• 한국작물학회지
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• 제12권
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• pp.31-36
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• 1972

조춘 저온기에 혼반용대두(풋콩)을 조기재배하는 경우 다수가능한 재식거리 및 질소질비료 시비적량을 구명하기 위하여 온상내에서 단일처리(1일 11시간)를 하고 오개수준의 재식거리 및 4개수준의 질소시비량(각 구 공히 인산과 가리는 표준시비량 시용)을 조합 적용하였다. 품종은 조생종인 북해일호를 공시하였으며 그 시험 결과를 요약하면 다음과 같다. (1) 일주당 협수, 입수, 및 분지수를 많이 착생시키기 위해서는 재식거리를 50cm$\times$10cm 및 30cm$\times$20cm 등 비교적 넓게 하는 것이 효과적이었으나 단위면적당 꼬투리 및 알맹이의 증수를 위해서는 오히려 평당주수가 월등히 많은 50cm$\times$5cm 및 30cm$\times$10cm 등 재식거리를 좁게 하는 것이 효과적이었다. (2) 단위면적당 꼬투리 및 알맹이의 다수를 위한 질소질비료의 시비적량은 표준시비량만으로 충분하다는 사실을 인정하였다.

• 한국식품영양과학회지
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• 제32권5호
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• pp.667-672
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• 2003

조리수율과 지방 보유율 및 보수력은 hydrocolloid 첨가구에 비하여 대조구가 가장 낮았으며 hydrocolloid는 식품의 증점성, 유화 안정성, gel형성, 피막형성 등의 기능을 가지고 있어서 가열중의 드립의 양을 감소시키고, 지방과 결합하여 지방보유율을 높일 수 있었다. pH는 조리전보다 조리후에 높아지는 경향을 나타냈고, 재가열시에는 조리후보다 같거나 약간 감소하는 경향을 나타냈으며 hydrocolloid 첨가구가 대조구에 비해 높은 경향을 나타냈다. 모든 실험군을 8일간 저장하는 동안 총균수는 큰 증가를 보이지 않았으며 황색포도상구균과 대장균 또한 검출되지 않아 저장기간동안 비교적 신선한 상태를 유지하고 있었다고 볼 수 있었다. 재가열한 대조구의 경도, 뭉침성, 부서짐성 등은 hydrocolloid를 첨가한 완자보다 높은 경향을 나타냈는데, 이는 hydrocolloid의 보수력과 유화안정성 때문이라고 할 수 있으며 결국 지방을 줄이면서 hydrocolloid와 두부를 첨가한 완자가 지방을 20% 첨가한 완자보다 조직적 특성이 비슷하거나 우수하여 지방 대체제로서의 hydrocolloid와 두부의 이용 가능성을 제시하였다. 대조구에 비하여 hydrocolloid를 첨가한 완자가 전반적인 관능수용도 역시 우수한 것으로 나타났다. 시료간의 유의적인 차이는 없었으나 제조 후의 다즙성, 조직감, 종합적인 품질은 xanthan gum 첨가구가 가장 좋았으며, 재가열한 제품에서는 sodium alginate 첨가구가 가장 좋았다. 이처럼 조직적인 특성과 함께 관능적인 면에서도 hydrocolloid첨가 완자가 대조구에 비해 좋은 결과를 나타낸 것은 저지방 기능성 육제품의 제조에 있어서 hydrocolloid첨가가 긍정적인 영향을 줄 수 있다는 것을 나타낸다.

• Korea-Australia Rheology Journal
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• 제20권2호
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• pp.51-58
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• 2008

This paper describes a two-step Tikhonov regularization procedure for converting the steady shear data generated by parallel-disk viscometers, in the presence of wall slip, into a shear stress-shear rate function and a wall shear stress-slip velocity functions. If the material under test has a yield stress or a critical wall shear stress below which no slip is observed the method will also provide an estimate of these stresses. Amplification of measurement noise is kept under control by the introduction of two separate regularization parameters and Generalized Cross Validation is used to guide the selection of these parameters. The performance of this procedure is demonstrated by applying it to the parallel disk data of an oil-in-water emulsion, of a foam and of a mayonnaise.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.836-842
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• 2004

An experiment was conducted to study the performance of broilers chicks (2 to 42 d of age) fed diets containing pearl millet (PM, Pennisetum typhoides), foxtail millet (FOM, Setaria italica) or finger millet (FIM, Elusine coracana) totally replacing (w/w) yellow maize (YM) with and with out supplementing non-starch polysaccharide (NSP) hydrolysing enzymes at the rate of 0.5 g/kg diet. Enzyme preparation contained amylase 2,400 units, hemi-cellulase 5,400 units, cellulase 12,000 units, protease 2,400 units and beta-glucanase 106 units/g. Each diet was fed to eight replicates (five female Vencob broilers/replicate) housed in stainless steel battery brooders. The estimated metabolizable energy (ME) contents of YM, PM, FOM and FIM were FM (PM) were about 3,389, 2,736, 3,303 and 2,846 kcal/kg, respectively. Total replacement of YM with FOM did not influence the body weight gain, ready to cook yield, relative weights of giblet, liver, intestine, lymphoid organs (bursa and spleen) and length of intestine, antibody titers and livability at 42 d of age. But the food efficiency decreased significantly in FOM fed broilers compared those fed YM. Further, the fat content in thigh muscle reduced with FOM fed groups compared to those fed YM. The performance of broilers decreased significantly in PM and FIM fed broilers compared to those fed YM. The relative weights of giblet, gizzard and liver increased in FIM fed groups compared to those fed YM as the principal source of energy in broilers. Incorporation of NSP hydrolysing enzymes in commercial broiler diets improved the efficiency of feed utilization during starter phase but not at 42 d of age. The results thus indicate that yellow maize can be replaced in toto on weight basis in commercial broiler diets without affecting the performance. Supplementation of NSP hydrolysing enzymes was beneficial in enhancing feed utilization during the starter phase.