• 한국환경과학회지
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• 제23권1호
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• pp.97-104
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• 2014

The sludge flotation/thickening apparatus equipped a micro-bubble generating pump was used to investigate micro-bubble generating properties on operational parameters. We evaluated micro-bubble generating properties as results to be operated the apparatus by operational parameters which are pump discharge pressure, air/water ratio(A/W ratio), air flow rate, and water flow rate. Micro-bubble generating efficiencies in pumps without recycling flow and with 50% of recycling flow was found to be very efficient on optimum A/W ratio from 1.06 to 3.62% and optimum A/W ratio from 1.05 to 4.06%, respectively. In condition of 3.6% of A/W ratio, we showed that the apparatus could be generated 36,000 ppm of micro-bubble concentration to be optimum treatment efficiency in sludge thickening process.

• 한국공간구조학회논문집
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• 제1권1호
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• pp.157-166
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• 2001

In general, the cutting pattern of the membrane structures is determined by dividing the complicated curved 3-D surface into several 2-D plane strip by using flattening technique. In this procedure, however, some discrepancies ore occurred between actual stresses of equilibrated state and designed uniform stresses because the material properties are not considered. These deviations can cause the critical structural problems, wrinkling or overstress, and thus a optimization process should be considered. In this paper, a new analytical method for determining an optimum cutting pattern considering material properties is presented. Here, iterative procedure is introduced to decrease the errors caused in numerical process. The optimization method proposed can diminish the deviations occurred by material properties and numerical errors, simultaneously. As a results, it is shown that the final stress distributions for the HP shell model are sufficiently near to design stress distributions, and it can be concluded that this method can be used to obtain the optimized cutting pattern of membrane structures.

• 폴리머
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• 제32권1호
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• pp.19-25
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• 2008

본 논문은 실리카복합재료인 치약제의 결합제 역할을 하는 수용성 폴리머인 carboxymethylcellulose (CMC)와 carbomer, Mg/Al silicate의 최적의 조성 비율을 구하여 치약제의 레올로지 속성을 개선하는 데에 목적이 있다. 실험계획법 중 혼합물 반응표면분석법을 적용하여 응력, 겔 강도, 늘어짐, 탄성에 대해 oscillatory 레오미터로 측정하였다. 실험 결과 CMC와 carbomer는 치약제의 겔 강도와 응력에 많은 영향을 미치고, CMC는 치약제의 늘어짐을 초래하며, CMC와 Mg/Al silicate가 탄성에 도움이 된다는 사실을 규명하였다. 반응치 최적화를 통해 최적의 폴리머 및 silicate 조성비를 구하여 실험한 결과 개선된 레올로지 속성의 치약제를 확인할 수 있었다.

• 한국염색가공학회지
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• 제21권4호
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• pp.11-22
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• 2009

This study surveys the optimum processing conditions of ATY for PET braiding for automotive hoses. For this purpose, high tenacity and low shrinkable PET filaments with three types of deniers are prepared. Twenty seven ATY specimens are manufactured with variation of feed speed and overfeed on the air jet texturing machine. The physical properties of various yam according to the ATY processing conditions are measured and analysed for deciding the optimum ATY processing condition. Two kinds of ATY filaments made under the optimum air texturing conditions are processed with variation of tpm, heat setting temperature and heat setting time on the 2-for-l twister and setting chamber, respectively. The optimum twisting and heat setting conditions are decided through analysis of the yam physical properties. Finally, the braiding fabric specimens are manufactured using conventional filament and newly developed filament made under optimum twisting and heat setting conditions. The bursting strengths of these braiding specimens are compared and discussed between two types of specimens.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.438-444
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• 2001

The objective of this study is to provide a simple methodology to find optimum processing conditions to fabricate sub-micron structured DVD-RAM substrates with superb optical and geometrical properties. It was found that the birefringence, which is regarded as one of the most important optical properties for an optical disk, was very sensitive to the mold wall temperature history. Also, the integrity of the replication, represented by the land-groove structure and the radial tilt were influenced by the mold temperature and the compression pressure. A set of optimum conditions were obtained by applying Design of Experiment and the objective functions composed of three different objectives.

• 한국식품영양과학회지
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• 제26권3호
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• pp.443-449
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• 1997

Four-dimensional response surface methodology was applied to determine the optimum preparation conditions and to monitor sensory qualities of canned oyster mushroom during preparation. The optimum preparation conditions predicted for each corresponding sensory parameter of canned oyster mushroom were 181.29 g of oyster mushroom 205.36 ml of solution and 6.49min of roasting time for color, 214.01g, 195.79ml and 5.07min for appearance, 227.71g, 224.26ml and 6.50min for flavor, 250.30g, 183.63ml and 17.32min for taste, 211.59g, 178.21ml and 17.79min for mouth-feel, 249,.02g, 188.79ml and 17.80min for overall palatability of canned oyster mushroom, respectively. The optimum conditions, which satisfied with all sensory properties of canned oyster mushroom, were 240g, 200ml and 17min for content of oyster mushroom, content of solution and roasting time, respectively. Sensory scored predicted at the optimum conditions were in good agreement with experimental ones.

• 한국농공학회논문집
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• 제55권3호
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• pp.25-33
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• 2013

In this study, the optimum mix proportions of rain garden structure concrete were decided and the mechanical properties were evaluated. Experimental parameters were blast furnace slag, hwang-toh, recycled aggregates and natural jute fibers. The target compressive strength and chloride ion penetration were more than 24 MPa and less than 1000 coulombs, respectively. The response surface method was used for statistical optimization of experimental results. The optimal mixing ratios of the blast furnace slag, hwang-toh, recycled coarse aggregate and jute fiber volume fraction were determined 59.98 %, 8.74 %, 12.12 % and 0.2 %, respectively. The compressive strength, flexural strength and chloride ion penetration test results of optimum mix ratio showed that the 24.56 MPa, 3.88 MPa and 999.08 columbs, respectively.

• 한국레이저가공학회지
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• 제7권2호
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• pp.1-10
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• 2004

This work was attempted to join SCP sheet and STS304 sheet by using Nd:YAC laser beam. SCP sheet has good formability and low cost, while STS304 has excellent corrosion resistance and mechanical properties in high temp. In this experiment, butt joint type was used to develop the tailored blank welding for dissimilar steel. Sheets which have different thermal properties. Computer simulation was conducted to obtain the off-set position for efficient welding by considering laser power, scanning speed, focal length and basic properties. The result showed that the optimum thermal distribution was obtained when the laser beam was irradiated at $0.05{\sim}0.1$ mm off-set toward the SCP sheet side. The experiment was conducted based on the result of computer simulation to show the same optimum conditions. Optimum conditions were 3KW in laser beam power, 6m/min in scanning speed, -0.5mm in focal position, 0.1mm off-set toward SCP. Microhardness test, tensile test, bulge test, optical microscopy, EDS, and XRD were performed to observe the microstructure around fusion zone and to evaluate the mechanical properties of optimum conditions, The weld zone had high microhardness values by the formation of the martensitic structure. Tensile test measured the strength of welded region by vertical to strain direction and the elongation of welded region by parallel to strain direction. Bulge test showed $52\%$ formability of the original materials. Bead shape, grain size, and martensitic structure were observed by the optical microscopy in the weld zone. Detailed results of EDS, XRD confirmed that the welded region was connected of martensitic structure.

• 약학회지
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• 제33권2호
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• pp.111-117
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• 1989

The optimum reaction conditions for the acid consuming capacity of aluminum silicate synthesized from the reaction of sodium silicate solution and potassium aluminum sulfate solution were investigated by Box-Wilson experimental design, and the micromeritic properties were examined by the means of BET $N_2$ adsorption, Hg penetrometer and methylen blue adsorption. The chemical composition of the samples were analyzed by gravitic method. The results were found to be as follows: optimum reaction temperature $54.7^{\circ}C$, both concentrations of reactant soln 15.7%, reactants molar ratio (Al/Si) 0.5 and drying temperature $65.0^{\circ}C$. The acid consuming capacity of the sample prepared by above optimum conditions was 68 ml and the chemical composition was $Al_2O_3{\cdot}3.6SiO_2{\cdot}3H_2O$. The relationship between acid consuming capacity and micromeritic properties could not found in the range of experiments. Therefore, it is assumed that the acid consuming mechanism of aluminum silicate depends on the neutralization of $Al_2O_3$ and buffer action of $SiO_2$ in sample.

• 한국식품과학회지
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• 제30권4호
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• pp.895-901
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• 1998

폐단백질을 활용하는 방도의 하나로 참깨박으로부터 불용성 단백질의 분리 효율성을 높이고 기능성을 개선하기 위하여 미생물이 생성하는 phytase와 protease를 처리하였다. 이때 참깨박 단백질의 용출을 위한 최적 pH, 최적 온도, 최적 처리시간과 최적 첨가효소량은 pH $10{\sim}12$까지의 알칼리 영역, $60^{\circ}C$, 11시간, phytase 900 unit+protease 60 unit이었다. 효소처리된 참깨박단백질은 거품 형성력과 거품 안정성이 대조구에 비해 크게 증가하였고, 유화력과 유화 안정성 및 유지 흡착력과 수분 흡착력도 효소처리구가 대조구에 비해 매우 증가하였다.