• Title/Summary/Keyword: 피치

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Electrochemical Characteristics of High Capacity Anode Composites Using Silicon and CNT for Lithium Ion Batteries (실리콘과 CNT를 사용한 리튬 이온 전지용 고용량 음극복합소재의 전기화학적 특성)

  • Lee, Tae Heon;Lee, Jong Dae
    • Korean Chemical Engineering Research
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    • v.60 no.3
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    • pp.446-451
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    • 2022

  • In this study, to improve capacity and cycle stability, the pitch coated nano silicon sheets/CNT composites were prepared through electrostatic bonding of nano silicon sheets and CNT. Silica sheets were synthesized by hydrolyzing TEOS on the crystal planes of NaCl, and then nano silicon sheets were prepared by using magnesiothermic reduction method. To fabricate the nano silicon sheets/CNT composites, the negatively charged CNT after the acid treatment was used to assemble the positively charged nano silicon sheets modified with APTES. THF as a solvent was used in the coating process of PFO pitch. The physical properties of the prepared anode composites were analysed by FE-SEM, XRD and EDS. The electrochemical performances of the synthesized anode composites were performed by current charge/discharge, rate performances, differential capacity and EIS tests in the electrolyte LiPF6 dissolve solvent (EC:DMC:EMC = 1:1:1 vol%). It was found that the anode material with high capacity and stability could be synthesized when high composition of silicon and conductivity of CNT were used. The pitch coated nano silicon sheets/CNT anode composites showed initial discharge capacity of 2344.9 mAh/g and the capacity retention ratio of 81% after 50 cycles. The electrochemical property of pitch coated anode material was more improved than that of the nano silicon sheets/CNT composites.

  • https://doi.org/10.9713/kcer.2022.60.3.446 인용 PDF KSCI

Improvement in flow and noise performances of small axial-flow fan for automotive fine dust sensor (차량용 미세먼지 센서용 소형 축류팬의 유동과 소음 성능 개선)

  • Younguk Song;Seo-Yoon Ryu;Cheolung Cheong;Inhiug Lee
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.1
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    • pp.7-15
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    • 2023

  • Recently, as interest in air quality in vehicles increases, the use of fine dust detection sensors for air quality measurement is becoming common. An axial-flow fan is inserted in the fine dust sensor installed in the air conditioning system in the vehicle to prevent dust from sinking directly on the sensor. When the sensor operates, the flow noise caused by the rotation of the axial-flow fan acts as a major noise source of the fine dust sensor. flow noise is recognized as one of the product competitiveness of fine dust sensors. In this study, the noise was gradually reduced at the same flow rate by improving the flow performance of the small axial flow fan. First, a virtual fan performance tester consisting of about 20 million grids was developed to analyze the aerodynamic performance of the target small axial-flow fan. In addition, the flow field was simulated by using compressible Large Eddy Simulation for direct computation of flow noise as well as high-accurate prediction of flow rate. The validity of numerical method are confirmed through the comparison of predicted results with experimental ones. After the effects of pitch angle on flow performance were analyzed using the verified numerical method, the pitch angle was determined to maximize the flow rate. It was found that the flow rate was increased by 8.1 % and noise was reduced by 0.8 dBA when the axial-flow fan with the optimum pitch angle was used.

  • https://doi.org/10.7776/ASK.2023.42.1.007 인용 PDF

Effects of the Daylight Disturbance on the Growth and Yield of Spray Chrysanthemum 'Yellow Cap' and 'Peach PangPang' (일조방해가 스프레이 국화 '옐로우캡'과 '피치팡팡'의 생육 및 수량에 미치는 영향)

  • Yuri Lee;Sang Kun Park
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.4
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    • pp.78-83
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    • 2024

  • This study was carried out to analyze the effect of changes in the light environment caused by the daylight disturbance on the growth, flowering, and cut flower quality of spray chrysanthemums. The spray chrysanthemum 'Yellow Cap' and 'Pitch PangPang' cultivars for cut flowers were artificially shaded to interfere with 66% of sunlight compared to the non-shading, and then the growing and flowering characteristics, and cut flower yield were investigated accordingly. There was no significant difference in the cut flower yield per unit area between the shading and the non-shading treatments. However, the number of days to flowering was 72.1 days for the 'Yellow Cap' and 65.2 days for the 'Pitch PangPang', which were delayed by 14.1 and 8.9 days, respectively, compared to the non-shading light. In the shading treatment, the flower diameter and the number of flowers also decreased by 10% and 15%, and 30% and 28% for both 'Yellow Cap' and 'Pitch PangPang', respectively. The stem length also decreased by 10% and 20%, the stem diameter by 23% and 37%, and fresh weight by 32% and 33%, respectively. The shading treatment delayed the flowering of chrysanthemums and reduced the growth such as flower diameter, number of flowers, and the length and weight of cut flowers. Based on these results, the daylight disturbance by artificial buildings is expected to reduce the productivity and quality of cut flowers by limiting the light intensity needed for chrysanthemum growth, flower bud differentiation, and flower development. Therefore, further research is needed on the rate of decrease in yield and market value according to the degree of shading to relieve damage to chrysanthemum growers caused by the daylight disturbance.

  • https://doi.org/10.23097/JPAF:2023.25(4).78 인용 PDF

열린마당 - 가르치며 배우는 시간, 생각을 바꿔준 '사내강사양성교육'

  • Hong, Ji-Hye
    • 월간산업보건
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    • s.364
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    • pp.62-63
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    • 2018

  • 고대 철학자 세네카는 '사람은 가르치면서 배운다'라는 명언을 남겼다. 배움은 가르침 속에도 존재한다는 뜻일 것이다. 사내강사양성교육 참여는 이 말의 뜻을 몸소 느낄 수 있는 기회였다. 교육이 시작되는 5월 16일 아침, 원주 치악산 호텔로 향했다. 많은 사람들 앞에서 발표해 본 경험이 적은 나는 교육시간이 다가올수록 발표를 해야 한다는 생각에 긴장되었다. 교육이 시작되고, 조별로 나누어 앉아 자신에 대해 1분 스피치를 하는 시간이 주어졌다.

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