한국 재래 나물콩 품종 및 계통의 콩나물 특성

황영현,이정동,조호영,권택화,정연신 慶北大學校農業科學技術硏究所 2002 慶北大農學誌 Vol.20 No.-

우수한 특성을 가진 나물콩 품종 육성을 위하여 국내 재래 나물콩 계통의 콩나물 특성을 분석한 결과는 다음과 같다. 1. 공시된 301품종 및 계통의 콩나물 전체길이의 범위는 9.5∼23.0cm, 하배축 길이는 5.9∼15.1cm, 뿌리 길이는 3.2∼9.2cm로 다양한 변이를 보였고, 수율에서도 121∼695%로 다양하게 분포하고 있다. 2. 공시된 301품종 및 계통의 종피색에 따른 콩나물 수율은 혼색종피종에서 409%로 가장 높게 나타났고, 백립중에 따른 콩나물 수율은 소립종일수록 높은 경향이었으며, 잔뿌리수는 흑색종피종과 갈색 종피종에서 현저히 적었다. 3. 콩나물 길이와 전체길이에 대한 뿌리길이의 비율, 수율을 기준으로 한 공시품종 및 계통들의 분포에서 장려품종보다 우수한 특성을 가지는 다수의 재래계통이 분포하고 있었다. 4. 콩나물 하배축의 색도는 백색도(L값)에서 장려품종이 재래계통에 비해 백색에 더 가까웠고, 적색도(a값)와 황색도(c값)는 장려품종보다 재래계통에서 높은 경향이었다. To develop good soybean varieties for sprouts. 285 indigenous lines and 16 recommending varieties were evaluated by the sprout and agronomic characteristics. The range of whole length, hypocotyl length, root length, and yield rate of sprouts was 9.5~23.0cm, 5.9~15.1cm, 3.2~9.2cm, and 121~695%, respectively. Yield rate of sprouts was the highest, 409%, in the lines of mixed seed coat color. At the same time, it was reversely proportional to seed weight : the smaller the seed weight, the higher the yield rate as in all other reports. The number of roots was significantly fewer in the lines of the black and the green seed coat color than others. Based on whole length, rate of root length, and yield rate of sprouts, many indigenous lines were evaluated much better than recommending varieties. In the hypocotyl color of sprouts, the brightness was higher in improved variety than indigenous lines but vice versa in redness and yellowness in general.

Starter 및 멸치액젓 첨가가 김치양념 및 겉절이 김치의 품질에 미치는 영향

최택권,박소희,유진현,임호수,조재선,황성연 한국식생활문화학회 2003 韓國食生活文化學會誌 Vol.18 No.2

양념에 Leu. mesenteroides, Lac plantarum의 젖산균과 멸치액젓 첨가가 김치 양념의 대장균군 제어, 속성촉진여부 및 관능적 특성에 미치는 영향을 조사하였다. Leu. mesenteroides과 젓갈을 첨가한 경우 초기 숙성이 촉진되나 후기 산패는 완만하였으며 Lac. plantarum의 첨가시에는 초기 숙성에는 큰 차이가 없고 후기 산패가 현저하게 진행되었다. 대장균군은 산도 0.80% 이상에서 사멸되었는데 leu. mesenteroides의 경우가 숙성이 촉진되어 보다 신속히 사멸시켰다. 총균수와 젖산균수는 초기에 starter 첨가구는 10^6CFU/mL 정도인데 반해서 starter를 첨가하지 않은 않은 처리구에서 총균수는 10^6CFU/mL , 젖산균수가 10^4CFU/mL 이었고 숙성 후에는 첨가균이 높은 수준을 유지하였다. 하지만 대체적으로 스타터의 첨가가 숙성 및 대장균에 크게 영향을 주지 못하는 경향으로 동일하게 나왔다. 관능적 특성에서는 Leu. mesenteroides 첨가구가 Lac. plantarum의 경우보다 우수하였다. 한편, 시판 겉절이 김치는 산도가 0.09~0.18%, ph 5.46~5.89, 총균수 2.2×10^6~3.1×10^7CFU/mL, 젖산균수는 2.1×10^4~6.6×10^5CFU/mL, 대장균수는 1.8×10^4~7.1×10^5CFU/mL, 염분 1.89%~2.51%으로 스타터 첨가 겉절이에 비해 ph와 염도를 제외한 품질 특성에서 전반적으로 낮은 값을 나타냈다. This study was performed in order to investigate the effect of Leuconostoc mesenteroides, Lactobacillus plantarum and salt fermented anchovy extracts on Kimchi sauce. The sauce was fermented more rapidly by addition of Leu. mesenteroids or salt fermented anchovy extracts on the early fermentation stage than the control, but it was fermented slowly on the late fermentation stage. When L. plantarum was added to the Kimchi on the early fermentation stage, the acidity of Kimchi didn't show a significant difference from the control, but acidity was remarkably increased on the late stage. Coliform group was disappeared when acidity of sauce was higher than 0.8% during fermentation. It was controlled by Leu. mesenteroides but not by L. plantarum. Total count and lactic acid bacterial count of the sauces with starter were 6.30×10^6~1.0×10^7 CFU/mL and 1.04~2.04×10^6 CFU/mL, respectively, but those of the control sauce were 10^6 CFU/mL and 10^4 CFU/mL, respectively. Those count of the sauce with starter were higher than those of the control sauce on the later stage of fermentation. Organoleptic quality of the sauce with Leu. mesenteroides was superior to that with L. plantarum.

Development of P3-K_0.69CrO₂ as an ultra-high-performance cathode material for K-ion batteries

Hwang, Jang-Yeon,Kim, Jongsoon,Yu, Tae-Yeon,Myung, Seung-Taek,Sun, Yang-Kook The Royal Society of Chemistry 2018 ENERGY AND ENVIRONMENTAL SCIENCE Vol.11 No.10

<P>Potassium-ion batteries (KIBs) are emerging as a promising energy storage technology because of their low cost and high energy density. However, the large size of K<SUP>+</SUP> ions hinders the reversible electrochemical potassium (de)insertion in the host structure, limiting the selection of suitable electrode materials for KIBs. Herein, we designed and exploited a new layered oxide, P3-type K0.69CrO2 (hereafter denoted as P3-K0.69CrO2), as a high-performance cathode for KIBs for the first time. The proposed P3-K0.69CrO2 cathode was successfully synthesized <I>via</I> an electrochemical ion-exchange route and exhibited the best cycling performance for a KIB cathode material to date. A combination of electrochemical profiles, <I>ex situ</I> X-ray diffraction, and first-principles calculations was used to understand the overall potassium storage mechanism of P3-K0.69CrO2. Based on a reversible phase transition, P3-K0.69CrO2 delivers a high discharge capacity of 100 mA h g<SUP>−1</SUP> and exhibits extremely high cycling stability with ∼65% retention over 1000 cycles at a 1C rate. Moreover, the K-ion hopping into the P3-K0.69CrO2 structure was extremely rapid, resulting in great power capability of up to a 10C rate with a capacity retention of ∼65% (<I>vs.</I> the capacity at 0.1C).</P>

The influence of consolidation temperature on in-plane and interlaminar mechanical properties of self-reinforced polypropylene composite

Hwang, Yeon-Taek,Kang, So-Young,Kim, Dong-Hyun,Kim, Hak-Sung Elsevier 2019 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.210 No.-

<P><B>Abstract</B></P> <P>In this work, the mechanical properties of self-reinforced polypropylene (SRPP) composite were investigated regarding their manufacturing process. The self-reinforced composite composed of polypropylene fiber and matrix were fabricated according to the consolidation temperature. Then, tensile and compressive tests were conducted to measure the mechanical properties such as strength and failure strain. Mode-I and Mode-II fracture toughness tests were performed to confirm the influence of consolidation temperature on interlaminar properties of SRPP composite. To evaluate crystal structure and thermal transition of the polypropylene fiber reinforcement, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses were carried out according to the consolidation temperature. Digital microscope and scanning electron microscope (SEM) were used to observe failure modes of the fractured SRPP composite specimens. Finally, the optimal consolidation temperature was suggested for improvement of in-plane and interlaminar mechanical properties of SRPP composite. It was also found that the superior impact characteristic of the optimally fabricated SRPP could be achieved under drop weight impact test.</P>

Intensive Plasmonic Flash Light Sintering of Copper Nanoinks Using a Band-Pass Light Filter for Highly Electrically Conductive Electrodes in Printed Electronics

Hwang, Yeon-Taek,Chung, Wan-Ho,Jang, Yong-Rae,Kim, Hak-Sung American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.13

<P>In this work, an intensive plasmonic flash light sintering technique was developed by using a band-pass light filter matching the plasmonic wavelength of the copper nanoparticles. The sintering characteristics, such as resistivity and microstructure, of the copper nanoink films were studied as a function of the range of the wavelength employed in the flash white light sintering. The flash white light irradiation conditions (e.g., wavelength range, irradiation energy, pulse number, on-time, and off-time) were optimized to obtain a high conductivity of the copper nanoink films without causing damage to the polyimide substrate. The wavelength range corresponding to the plasmonic wavelength of the copper nanoparticles could efficiently sinter the copper nanoink and enhance its conductivity. Ultimately, the sintered copper nanoink films under optimal light sintering conditions showed the lowest resistivity (6.97 mu Omega.cm), which was only 4.1 times higher than that of bulk copper films (1.68 mu Omega.cm)</P>

The Ultrafast and Eco-friendly Reduction of Graphene Oxide Using a UV–IR Assisted Intense Pulsed Light and Its Application as Supercapacitor

Yeon-Taek Hwang,Hak-Sung Kim 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1

In this work, a UV–IR assisted intense pulsed light (IPL) process was used for the reduction of graphene oxide (GO). It was found that the reduction efficiency of GO was enhanced compared to those of other reduction methods such as only intense pulsed light irradiation or other chemical method. An optimal condition for the reduction of GO was investigated by varying conditions and combinations of the UV–IR assisted IPL. The graphene films reduced by the UV–IR assisted IPL were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. As a result, we found the optimum condition of the UV–IR assisted IPL process for the reduction of GO without any damage to the GO sheet. Also, the reduced GO based electrode was fabricated with nickel foam for the electrical double layer capacitor and its performance was tested using three electrode electrochemical method.

탄소섬유강화 직조 복합재료의 미시역학 기반 충격 거동 해석

황연택(Yeon-Taek Hwang),김학성(Hak-Sung Kim) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11

Synthesis of sulfonated polyketone membranes by a direct sulfonation reaction and their properties

Seong Yeon Hwang,Jae Bum An,Byoung Chul Park,Taekeun Kim,Taek-Sung Hwang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-

In this study, sulfonated polyketone cation exchange (SPOK) membranes were prepared by a directsulfonation method and evaluated according to the concentration of sulfonating agent, reaction time andreaction temperature. The physicochemical properties of these membranes were measured to confirmtheir optimal synthetic conditions. The sulfur content in the SPOK membranes increased with increasing sulfonating agent concentration,reaction time and reaction temperature. The ion exchange capacity, water uptake and swelling ratio ofthese membranes increased with increasing sulfur content. The highest ion exchange capacity for themembranes was 1.01 meq/g. From the measured electrical properties, the electrical resistance showed a tendency to decrease withincreasing sulfonation conversion, and the lowest electrical resistance was 0.4 V cm2 when thesulfonation conversion was 59.6%. To evaluate the possible application of the SPOK membranes tomembrane capacitive deionization (MCDI) modules, their chemical resistance, durability and tensilestrength were measured. The performance-limiting conditions for the tensile strength were 0.3 wt%chlorosulfonic acid (CSA)/CF, 20 C and 60 min.

폴리프로필렌 자기보강/유리섬유강화 하이브리드 복합재의 저속 충돌 특성

황연택(Yeon-Taek Hwang),강소영(So-Young-Kang),김도형(Do-Hyoung-Kim),윤덕우(Deok-Woo Yun),강현민(Hyun-Min Kang),김학성(Hak-Sung KIm) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.4

파장 영역 조절된 백색광을 통한 구리 나노 잉크 소결 연구

황연택(Yeon-Taek Hwang),정완호(Wan-Ho Chung),장용래(Yong-Rae Chang),김학성(Hak-Sung Kim) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

In this paper, wavelength of the white light was controlled by Cut-off filters. Also, the flash white light irradiation condition was optimized to obtain the high conductivity of copper film. The microstructures of the sintered copper films were observed using a scanning electron microscope (SEM). The sheet resistance of the sintered copper films was measured using a four-point probe method. From these results, the sheet resistance of wavelength controlled flash light sintered copper films decreased than that of no-filtered flash light sintered copper films. Therefore, it is expected that wavelength controlled flash light will be used in the future in highly electrical conductive electrodes of printed electronics.