• Geomechanics and Engineering
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• 제32권4호
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• pp.361-373
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• 2023

This study aimed to investigate the engineering properties and mechanical behaviors of polymer-fibers treated sand. Para rubber (PR), natural fiber (NF), and geosynthetic fiber (GF) were used to reinforce poorly graded sand. A series of unconfined compressive and splitting tensile strength tests were performed to analyze the engineering behaviors and strength enhancement mechanism. The experiment results indicated that the PR-fibers mixture could firmly enhance the strength properties of sand. The stress-strain characteristics and failure patterns have been changed due to the increase of PR and fibers content. The presence of PR and fibers strengthened the sand and enhanced the stiffness and ductility behavior of the mixture. The stiffness of reinforced sand reaches an optimum state when both NF and GF are 0.5%, while the optimum PR contents are 20% and 22.5% for the mixture with NF and GF, respectively. An addition of PR and fiber into sand contributed to increasing interlocking zone and bonding of PR-sand interfacial.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.81-89
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• 2023

The purpose of this study is to demonstrate the potential enhancement of the flavonoid contents from Agastache rugosa, which can be obtained as raw materials for functional products in the food medicine industry by identifying important factors for efficient preparation to save costs and time in terms of economic factors. For this reason, response surface methodology using Box-Behnken design was used to optimize the extraction conditions for the maximum yield of seven major compounds from A. rugosa. The optimum conditions were obtained with an ethanol concentration of 60.0%, a temperature of 50 ℃, and an extraction time of 33.6 min, meaning that the regression analysis fits the experimental data well. Under these conditions, the seven major compounds 1-7 had observed values of 2.169, 2.135, 0.697, 2.485, 0.105, 1.247, and 0.551%, respectively. These results show that the observed values are in good agreement with the predicted values in the regression model. This process for optimization study exhibited a basic protocol for obtaining stable ingredients from A. rugosa that are appropriate for the development of effective functional products.

• Geomechanics and Engineering
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• 제22권2호
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• pp.143-152
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• 2020

In this research, soil samples of the Kerman sedimentary basin, Iran, were investigated through laboratory tests such as petrography (Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD)), physical and mechanical characteristics tests. The soil in this area is dominantly CL. The petrography results showed that the dominant clay mineral is Illite. This soil has made some problems in the earth dams due to the low shear strength. In this study, a set of samples were prepared by adding different amounts of lime. Next, the petrography and strength tests at the optimum moisture content were performed. The results of SEM analysis showed substantial changes in the soil structure after the addition of lime. The primary structure was porous and granular that was changed to a uniform and solid after the lime was added. According to XRD results, dominant mineral in none stabilized soil and stabilized soil are Illite and calcite, respectively. The pozzolanic reaction resulted in the reduction of clay minerals in the stabilized samples and calcite was known as the soil hardener material that led to an increase in soil strength. An increase in the hydrated lime leads to a decrease in their maximum dry unit weight and an increase in their optimum moisture content. Furthermore, increasing the hydrated lime content enhanced the Unconfined Compressive Strength (UCS) and soil's optimum moisture. An increase in the strength is significantly affected by the curing time and hydrated lime contents, as the maximum compressive strength is achieved at 7% hydrated lime. Moreover, the maximum increase in the California Bearing Ratio (CBR) achieved in clay soils mixed with 8% hydrated lime.

• 한국환경복원기술학회지
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• 제7권5호
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• pp.94-99
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• 2004

This study was carried out to find out what is the optimum conditions for RAPD of Zelkova serata. We changes the factors what affect to PCR band patterns, as a result, we established the optimum conditions as follows; template DNA 100mg, Primer 0.25uM, dNTP 100mM, Taq polymerase 1.0u, and total reaction volume was filled up to 10uL with distilled water. As the amount of primers went higher, PCR reaction rates were lowered. This reason was cause by exhaustion of primers during initial reaction. The amount of dNTP didn't showed noticable differtations between the range, but the optimum amount was 100mM for efficiency. Taq polymerase 1.0 unit was the best in the range. As the concentration of polymerase were increased, many non-specific bands were appeared, In primer selection, most Openron Random Primers are amplified in this experiment. The primers GC contents were 60, and set A, B, C, D, E, X were tested. Thermal cycler(ASTEC PC808, Japan) condition was, $95^{\circ}C$, 5min, initial denaturation, $94^{\circ}C$, 20sec, denaturation, $37^{\circ}C$, 40sec, annealing, $72^{\circ}C$, 1min, extention, 45cycle repeated and final extention $72^{\circ}C$10min.

• 한국가금학회지
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• 제24권2호
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• pp.59-66
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• 1997

Optimum drying conditions to utilize porcine blood from slaughter house for blood meals, and the effects of blood meals on growth in broiler chicks were investigated. Moisture and protein con-tents of slaughter porcine blood were 79.8 and 16.4%, respectively. The protein contents of the flash dried blood meals at 80˚C were not different from those of the spray dried blood meals at 160 and 190˚C, but higher by 17% relative to those of the spray dried blood meals at 80 and 120˚C. Results from protein analysis by SDS-polyacrylamide electrophoresis showed that flash dried blood meals at 80˚C and spray dried blood meals at 160˚C were better than spray dried blood meals at 80, 120 and 190˚C in terms of protein quality. In Feeding Trial I with broiler chicks, body weights of chicks fed 2, 4 and 6% flash dried blood meal diets at 80˚C were increased at 35 days by 5.6, 7.9 and 4.0%, respectively, compared to control group(P<0.05). In Feeding Trial II, body weights of chicks fed 4 and 6% flash dried blood meal diets at 80˚C were increased at 42 days by 4.9 and 5.3%, respectively, compared to control group(P<0.05). Feed conversion ratios of chicks fed diets 4 and 6% flash dried blood meal diets at 80˚C were significantly improved at 42 days by 7.0 and 3.7%, respectively, compared to that of control group(P<0.05). The optimum drying condition of slaughter porcine blood seemed to be the flash drying method at 80˚C

• 한국생활과학회지
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• 제23권2호
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• pp.357-366
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• 2014

In this study, we manufactured mung bean Dasik (pattern pressed candy) after selecting the optimum roasting conditions through physiochemical analysis and sensory evaluation. Then anti-oxidative abilities of roasted mung bean were measured in order to develop beauty food (Dasik) using roasted mung bean. In the content of vitexin and isovitexin of roasted mung bean, about 10 times the vitexin in the seed(60.85 mg/g) is found in the skin of raw mung bean, and about 9 times the isovitexin in the seed(71.42 mg/g) is also found in the peel. As a result of analyzing the seed and peel of mung bean after roasting it for 10, 20 and 30 minutes respectively, the optimum roasting condition is thought to be $110^{\circ}C$ for 30 minutes as the contents of vitexin and isovitexin showed the highest values of 104.94 mg/g and 122.02 mg/g respectively when the mung bean was roasted at $110^{\circ}C$ for 30 minutes. In the anti-oxidative activity evaluation of the optimum mung bean Dasik, the total content of phenol was shown to be 0.15 mg/mL, and the total content of flavonoid was shown to be 0.026 mg/mL. The DPPH radical scavenging ability showed a high vitality of 58.19%, and the ABTS radical scavenging ability was shown to be 13.26%.

• 한국미생물·생명공학회지
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• 제17권1호
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• pp.35-45
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• 1989

Streptococcus thermophilus 510으로부터 $\beta$-galactosidase의 생성조건은 탄소원으로 0.5% lactose를 첨가한 배지에서 초기 pH7.0, 배양온도 37$^{\circ}C$, 배양기간 18시간이었다. 배양여액으로부터 $\beta$-galactosidase를 ammonium sulfate 분획, 핵산의 제거, Sephadex G-200 gel filtration 및 DEAE-Sephadex A-50 ion exchange chromatography 등의 4단계 정제과정을 거쳐 정제한 결과 18배 정제되어 단일 단백질로 분리되었다. 정제효소의 활성 최적온도는 5$0^{\circ}C$, 최적 pH는 7.0이었고, 효소활성이 Mn$^{2+}$, $K^+$과 같은 금속이온과 dithiothreitol, 2-mercaptoethanol에 의해 촉진되었고, Hg$^{2+}$, $Zn^{2+}$, Co$^{2+}$, $Ca^{2+}$, EDTA, 8-hydroxyquinoline, galactose 등에 의해 저해되었다. 효소의 분자량이 520,000, 합성기질인 ONPG에 대한 $K_{m}$ 은 1,25mM, V$_{max}$는 88.50 $\mu$mole/min.mg protein이었고, 주종 아미노산은 glutainic acid, aspartic acid, leucine 및 valine이었다.

• 대한안전경영과학회지
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• 제12권1호
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• pp.113-118
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• 2010

"Domestic delivery service" is defined the service to deliver goods or packages from point of senders to point of receiver. With the characteristics of door to door, it is must a service provider should know the exact location of destination assuring best utilization of moving path. Generally, location information consist of postal code and address only, which result in difficulties to identify the precise location of destination. It is relatively less correlated between the information that address refers and practical location in Korea address system. For example, the next door to house number 100 is not always house number 101. Therefore, a delivery man additionally uses a paper map or a GPS navigation which carry extra job to input every code of location to the device in order to know precise location. It is also very inconvenient that every delivery man identify the location that address information refers and make a personal decision of the optimum moving path dropping each destination without calculating provisioning process of whole delivery path. As explained above, it is inefficient to find information delivery service required and to generate the optimum path. In results, these difficulties bring in delay of service and increase of cost. In this point, the contents of the thesis suggest a GPS navigation system easy to obtain accuracy of delivery information which enables to automate optimum moving path based on RFID which contains location information.

• 한국식품저장유통학회지
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• 제17권2호
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• pp.261-266
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• 2010

식물체의 플라보노이드 성분 함량 분석에 필요한 적정 가수분해 조건을 구명하기 위하여 은행잎을 이용하여 중심합성법으로 설계한 산 가수분해 시간과 HCl 농도에 따라 myricetin, quercetin, kaempferol 함량을 HPLC로 분석하고, SAS의 반응표면분석법으로 산 가수분해 조건의 최적화를 시도하였다. HCl 0.5~2.5 M, 0.5~2.5시간 범위 내에서 10개의 구간을 잡아서 최적화한 결과 1.5~1.9 M의 HCl 농도와 1.4~2.0시간의 가수분해 조건에서 myricetin, quercetin, kaempferol 성분이 가장 높았다. Superimposing하여 구한 식물체의 플라보노이드의 적정 가수분해 조건은 HCl 1.5 M, 1.5시간이었으며, 이 조건에서 구한 플라보노이드 함량의 예측치와 측정치는 95% 이상 일치하였다. 본 연구에서 구한 적정 가수분해 조건을 이용하여 녹차잎, 무화과잎, 상동나무잎의 플라보노이드 함량을 분석하여 보았다.

• 한국주조공학회지
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• 제18권4호
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• pp.383-388
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• 1998

Effects of $CaCN_2$ addition on the grain refinement in the AM60 magnesium ingots were investigated. The effects of the $CaCN_2$ are estimated with different inoculation temperatures, inoculation contents, and holding time to find out the optimum condition. AM60 alloy was melted in the low carbon steel crucible by cylindrical electric furnace under an argon atmosphere. The melting and casting apparatus is specially designed for magnesium alloys. The grain size of AM60 magnesium alloy decreased significantly with an increase in $CaCN_2$ content and, at 0.8 wt% $CaCN_2$ or more, grain size becomes constant at about $85 {\mu}m$. The optimum condition was obtained in the 0.8 wt% $CaCN_2$ for holding molten metal of 30 min. at the temperature of $710^{\circ}C$. The tensile properties of AM60 magnesium alloys were improved due to grain refinement by addition of $CaCN_2$. In the optimum condition, the yield strength, tensile strength and elongation were ${\sigma}_{0.2}=107 MPa$, ${\sigma}_{T.S}=234 MPa$ and e=14.2%. The variation of stress with strain obeyed the relationship of the ${\sigma}=K{\varepsilon}^n$. The strain-hardening exponent, n and strength coefficient, K obtained in the 0.8 wt% $CaCN_2$ added AM 60 magnesium alloy were n=0.21 and K=390 MPa.