• 전기학회논문지
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• 제66권2호
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• pp.357-362
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• 2017

Among the lithium metal oxides for asymmetric hybrid supercapacitor, $Li_4Ti_5O_{12}(LTO)$ is an emerging electrode material as zero-stain material in volume change during the with the charging and discharging processes. The pulverized LTO powder was observed to show the enhanced capacity from 120 mAh/g to 156 mAh/g at C-rate (10, 100 C). Hybrid supercapacitor module(48V, 416F) was fabricated using an asymmetric hybrid capacitor with a capacitance of 7500F. As a result of the measurement of C-rate characteristics, the module shows that the discharge time is drastically reduced at more than 50C, and the ESR and voltage drop characteristics are increased. The energy density and power density were reduced under high C-rate conditions. When designing asymmetric hybrid supercapacitor module, the C-rate and ESR should be considered As a result of measuring the 5 kw UPS, it was discharged at the current of 116A~170A during the discharge in the voltage range of 48V~30V, and the compensation time at discharge was measured to be about 33.2s. Experimental results show that it can be applied to applications related to stabilization of power quality by applying hybrid supercapacitor module.

• 한국자원식물학회지
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• 제33권6호
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• pp.586-596
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• 2020

Chionanthus retusus has been used for landscaping and gardening trees, foods and medicines. This study was carried out to analyze the effect of fertilization on the growth performance of container seedlings (1-year-old) in C. retusus. We used multifeed 19 (MF) as a fertilizer, and measured the height, root collar diameter (RCD), biomass, seedling quality index (SQI) chlorophyll contents and chlorophyll fluorescence of the seedlings. The findings of this paper showed that the height, RCD, H/D ratio, T/R ratio and the fresh and dry weight of seedlings increased after fertilization. The moisture content of the stem and root did not show any significant difference among fertilizations, except in the case of the leaf. Production distribution such as the dry weight ratio of leaves and the stem dry weight ratio of fertilized seedlings had a higher value than that of non-treatment. SQI was the highest in MF 1,000 mg/L and 2,000 mg/L treatment. Chlorophyll contents (SPAD value) also increased with the increase in fertilization concentrations. Chlorophyll fluorescence (F_v/F_m) showed the highest value of 0.8 in MF 2,000 mg/L treatment.

• 천문학회보
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• 제39권1호
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• pp.75.2-75.2
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• 2014

We have developed a set of daily solar flare peak flux forecast models using the multiple linear regression (MLR), the auto regression (AR), and artificial neural network (ANN) methods. We consider input parameters as solar activity data from January 1996 to December 2013 such as sunspot area, X-ray flare peak flux, weighted total flux $T_F=1{\times}F_C+10{\times}F_M+100{\times}F_X$ of previous day, mean flare rates of a given McIntosh sunspot group (Zpc), and a Mount Wilson magnetic classification. We compute the hitting rate that is defined as the fraction of the events whose absolute differences between the observed and predicted flare fluxes in a logarithm scale are ${\leq}$ 0.5. The best three parameters related to the observed flare peak flux are as follows: weighted total flare flux of previous day (r=0.5), Mount Wilson magnetic classification (r=0.33), and McIntosh sunspot group (r=0.3). The hitting rates of flares stronger than the M5 class, which is regarded to be significant for space weather forecast, are as follows: 30% for the auto regression method and 69% for the neural network method.

• 원예과학기술지
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• 제33권1호
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• pp.143-148
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• 2015

'URI 2010-6'은 우리꽃종묘에서 2011년 종간 교잡종인 'Evergreen Emerald'을 자방친으로 D. chinensis 'Ruby'를 화분친으로 실시한 교잡의 $F_1$ 후대로부터 선발, 육성한 패랭이꽃속 신품종이다. 2007년 교배실생 개체를 획득하였고, 2008년부터 2010년까지 3년 동안의 생육특성검정을 통해 선발하여 2011년 국립종자원에 'URI 2010-6'로 신품종 등록하였다(품종보호: 제4431호). 'URI 2010-6'의 화색은 주로 밝은 적색(Red, N79C)이며, 2차색으로 백색(White, N155C)이 꽃잎 가장자리와 꽃잎에 반점형태로 발현되는 석죽형의 홑꽃이다. 또한 꽃의 직경은 2.7cm, 길이는 0.8cm이고, 개화 지속기간은 평균 150일 정도로 장기개화가 가능하며, 겨울철에도 상록성이 우수하다.

• Structural Engineering and Mechanics
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• 제84권1호
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• pp.17-33
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• 2022

An experimental study is carried out to investigate the performance of the cutting tool regarding the insert wear, surface roughness, cutting forces, cutting power and material removal rate of three coated carbides GC2015 (TiCN-Al₂O₃-TiN), GC4215 (Al₂O₃-Ti(C,N)) and GC1015 (TiN) during the dry turning of AISI4140 steel. For this purpose, a Taguchi design (L₉) was adopted for the planning of the experiments, the effects of cutting parameters on the surface roughness (R_a), tangential cutting force (F_z), the cutting power (P_c) and the material removal rate (MRR) were studied using analysis of variance (ANOVA), the response surface methodology (RSM) was used for mathematical modeling, with which linear mathematical models were developed for forecasting of R_a, F_z, P_c and MRR as a function of cutting parameters (V_c, f, and a_p). Then, Multi-Objective Ant Lion Optimizer (MOALO) has been implemented for multi-objective optimization which allows manufacturers to enhance the production performances of the machined parts. Furthermore, in order to characterize and quantify the flank wear of the tested tools, some machining experiments were performed for 5 minutes of turning under a depth of 0.5 mm, a feed rate of 0.08 mm/rev, and a cutting speed of 350 m/min. The wear results led to a ratio (V_B-GC4215/V_B-GC2015) of 2.03 and (V_B-GC1015/V_B-GC2015) of 4.43, thus demonstrating the efficiency of the cutting insert GC2015. Moreover, SEM analysis shows the main wear mechanisms represented by abrasion, adhesion and chipping.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1415-1423
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• 2010

An extracellular xylanase was purified to homogeneity by sequential chromatography of Fomitopsis pinicola culture supernatants on a DEAE-Sepharose column, a gel filtration column, and then on a MonoQ column with fast protein liquid chromatography. The relative molecular mass of the F. pinicola xylanase was determined to be 58 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and by size-exclusion chromatography, indicating that the enzyme is a monomer. The hydrolytic activity of the xylanase had a pH optimum of 4.5 and a temperature optimum of $70^{\circ}C$. The enzyme showed a $t_{1/2}$ value of 33 h at $70^{\circ}C$ and catalytic efficiency ($k_{cat}=77.4\;s^{-1}$, $k_{cat}/K_m$=22.7 mg/ml/s) for oatspelt xylan. Its internal amino acid sequences showed a significant homology with hydrolases from glycoside hydrolase (GH) family 10, indicating that the F. pinicola xylanase is a member of GH family 10.

• 한국지반공학회논문집
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• 제33권2호
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• pp.27-34
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• 2017

국내 건설 현장에서는 다양한 흙막이 공법이 적용되고 있으며 깊은 지하굴착에는 연속주열식공법(C.I.P)이 많이 적용되고 있다. 그러나 여러 단점들이 있어 이를 보완하기 위하여 PHC 말뚝을 이용한 흙막이 공법이 개발되었다. PHC 말뚝을 이용한 흙막이 공법은 품질이 균질하고 강성이 우수하여 안정성의 확보에 유리한 장점이 있다. PHC-W 말뚝은 PHC 말뚝의 단면을 변경한 제품으로, 수평 토압에 저항하기 위한 최적 설계를 통해 제작되었다. 그리고 KS F 4306 시험을 통하여 휨 모멘트 및 전단강도의 증가효과를 검증하였으며 휨 모멘트와 전단강도는 KS 기준보다 약 42%, 98% 증가되었다.

• 생명과학회지
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• 제30권10호
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• pp.851-859
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• 2020

뿌리, 잎, 꽃이 하얀색인 삼백초는 항균 활성 및 항암 효과를 갖는 것으로 알려져 있다. 본 연구에서는 SCEA의 항산화 활성과 멜라닌 합성에 미치는 영향을 조사하고자 하였다. SCEA를 헥산, 에틸 아세테이트, 부탄올 및 증류수로 분획 하였다. 용매 분획 중 가장 높은 항산화 활성을 갖는 ethyl acetate 분획물이 본 연구에 사용되었다. DPPH radical 소거능에서는 64 ㎍/ml의 SCEA는 양성 대조군과 비교하여 62% 라디칼 소거능을 보였다. 환원력 시험에서 64 ㎍/ml의 SCEA는 양성 대조군으로 사용된 비타민 C보다 33% 더 낮은 감소력을 보였다. Tyrosinase 활성은 공시험군에 비해 64 ㎍/ml의 SCEA 처리군에서 26% 증가했다. 또한, 64 ㎍/ml의 SCEA는 Dopa 산화력 분석에서 공시험군과 비교하여 44%의 멜라닌 합성을 증가시켰다. MTT 분석 결과 SCEA는 0.5 ㎍/ml 이상의 세포 독성을 나타냈다. 1 ㎍/ml의 SCEA는 멜라닌 합성을 살아있는 세포에서 69% 증가시켰다. 또한 SCEA 분획을 실리카 칼럼 크로마토그래피로 13 개의 분획으로 분리 하였다. 특히, Fr. 2는 DPPH 라디칼 소거 활성이 가장 높았으며, 멜라닌 합성이 감소되었다. 또한 SCEA는 살아있는 세포인 B16F1에서 멜라닌 생성을 촉진시켰다. LC-MASS는 Fr. 2의 분자량이 239임을 보여 주었다. 따라서 위의 결과는 SCEA가 멜라닌 합성 촉진과 관련된 천연흑모 모발화장품 개발에 사용될 수 있음을 시사한다.

• 한국염색가공학회지
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• 제34권2호
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• pp.93-101
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• 2022

In this study, the dyeing properties of supercritical fluid dyed cotton fabrics were investigated which use two types of dyes, such as C.I. Disperse orange and C.I. Disperse red 167. Dyeing temperature, pressure and leveling time were equally applied at 130 ℃, 250 bar, and 60 minutes with reference to the related literature, and experiments were performed at concentrations of 0.04, 0.1, 0.4 and 0.8 % o.w.f with different concentrations. Dyeability was confirmed through measurement of washing fastness and color coordinate, and a calibration curve of each dye was drawn up and the absorbance of the residual dye was measured to confirm the amount of residual dye and the dye exhaustion rate at the corresponding concentration. As a result of color difference measurement, as the concentration increased, the L^* value decreased and the K/S value increased. However, as the concentration increased, the increase in K/S value decreased compared to the input amount, and this tendency was more obvious in C.I. Disperse red 167 than in C.I. Disperse orange 155. The dye exhaustion rate which was calculated by using the amount of residual dye in the pot was also C.I. Disperse orange 155 was 96.16 % and C.I. Disperse red 167 was 94.57 %. However, as the dyeing concentration increased, the dye exhaustion rate decreased, that C.I. Disperse orange was 95.33 % and C.I. Disperse red 167 was 90.63 %. As a result of the washing fastness test for both dyes, dyed samples of which concentrations were 0.4 and 0.8 % o.w.f decreased by 0.5 ~ 1.0 grade. This is predicted because the dye did not completely adhere to the amorphous region of the cotton fiber and the dye simply adsorbed. The fastness to rubbing also maintained at least grade 3-4 up to the 0.1 % o.w.f concentration, but at the concentration of 0.4 % o.w.f or higher, it fell to grade 1 or lower, showing a very poor friction fastness.

• 한국환경과학회지
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• 제11권1호
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• pp.33-40
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• 2002

An antimicrobial substance-producing microorganism was isolated from soil samples. Based of the taxonomic characteristics of its morphological, cultural, physiological properties and 16s rRNA sequence alignment, this microorganism was identified as Pseudomonas aeruginosa, and we named Pseudomonas aeruginosa EL-KM. The optimal culture condition for production of antimicrobial substance was 1% mannitol, 0.4% yeast extract, 0.5% Nacl, 0.2% $K_2SO_4$, 100$\mu$M $MgSO_4$.$7H_2O$, 10$\mu$M $CaCl_2$.$2H_2O$, 1$\mu$M $FeSO_4$.$7H_2O$, 1$\mu$M $MnSO_4$.$4-5H_2O$, initial pH 7 and 200 rpm at 3$0^{\circ}C$. The purification of the antimicrbial substance was performed by silica gel column chromatographys, and fraction with TLC $R_f$ 0.77 value represented good antimicrobial activity. The crude antimicrbial substance was stable within a pH range of 3-10 and temperature range of 4$^{\circ}C$-121$^{\circ}C$ autoclaving. This crude antibacterial substance acted as bacteriolytic agent against Vibrio cholerae non-Ol ATCC 25872, and also exhibited excellent properties, when the substance was demonstrated against many other gram-positive, gram-negative bacteria, yeast and fungi.