• Title/Summary/Keyword: LED Cell

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Mini-grain counter by light-screen method of IRLED and Solar Cell (IRLED와 Solar Cell의 광막형성방식에 의한 mini-grain 계수기)

  • Cho, Si-Hyeong;Park, Chan-Won
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1714-1715
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    • 2008
  • 본 연구는 IR-LED에 의한 빔 발생기와 Solar Cell에 의한 빔 검출기로 구성되어 물체가 이 사이로 통과하면 미소한 부분의 빔을 변화시켜 이때 발생하는 펄스를 카운트하는 장치이다. 가볍고 크기가 작아 계수하기 힘든 꽃의 씨앗이나 야채 등의 종자 특히, 농업분야에서 계수할 때 적용되는 장치이며, 낙하방법으로 검출하므로 물체가 중복되어 계수되지 않고 크기, 종류, 모양에 상관없이 검출할 수 있게 구성된 시스템이다.

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Improvement of PWM Driving Control Characteristics for Low Power LED Security Light (저전력형 LED 보안등의 PWM형 구동제어 특성 개선)

  • Park, Hyung-Jun;Kim, Nag-Cheol;Kim, In-Su
    • Journal of IKEEE
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    • v.21 no.4
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    • pp.368-374
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    • 2017
  • In this Paper, we developed a low power type LED security light using LED lighting that substitutes a 220[V] commercial power source for a solar cell module instead of a halogen or a sodium lamp. in addition, a PWM type drive control circuit is designed to minimize the heat generation problem and the drive current of the LED drive controller. in developed system, The light efficiency measurement value is 93.6[lm/W], and a high precision temperature sensor is used inside the controller to control the heat generation of the LED lamp. In order to eliminate the high heat generated from the LED lamp, it is designed to disperse quickly into the atmosphere through the metal insertion type heat sink. The heat control range of LED lighting was $50-55[^{\circ}C]$. The luminous flux and the lighting speed of the LED security lamp were 0.5[s], and the beam diffusion angle of the LED lamp was about $110[^{\circ}C]$ by the light distribution curve based on the height of 6[m].

Transciver system using of solar cell (태양전지를 이용한 송.수신기)

  • 손승만;류지원;연제문;구경완;이명섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.417-420
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    • 2000
  • 태양전지는 빛에너지를 전기에너지로 변환시켜주는 에너지변환 소자이다. 본 논문에서는 이 태양전지를 수신기의 전원 겸 안테나로써 사용하고자 한다. 태양전지를 수신기의 안테나로 사용하기 위해서는 태양전지가 받아 들이는 빛에너지에 음성신호를 인가해주어야 한다. 실험에서는 일정하지 않은 음성신호대신 Function Generator를 이용하여 신호를 넣어주고 이 신호를 LM741과 KA2904 내의 OP-amp를 통하여 증폭시킨 후 발광 다이오드(LED)에 인가시켜 주었다. LED의 광신호를 Solar-Cell이 받아들여, 직류전압은 전원으로 사용되고 교류신호는 음성신호로 사용된다. 본 실험은 빛을 이용한 무선 송·수신기의 기초적인 단계에 불과하나 고도의 기술이 필요하지 않으므로 그 파생효과와 발전 방향은 무궁무진하다고 할 수 있다.

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Antitumor effects of valdecoxib on hypopharyngeal squamous carcinoma cells

  • Trang, Nguyen Thi Kieu;Yoo, Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.6
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    • pp.439-446
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    • 2022
  • The antitumoral effects of valdecoxib (Val), an United States Food and Drug Administration-approved anti-inflammatory drug that was withdrawn due to the side effects of increased risk of cardiovascular adverse events, were investigated in hypopharyngeal squamous cell carcinoma cells by performing a cell viability assay, transwell assay, immunofluorescence imaging, and Western blotting. Val markedly inhibited cell viability with an IC50 of 67.3 µM after 48 h of treatment, and also downregulated cell cycle proteins such as Cdks and their regulatory cyclin units. Cell migration and invasion were severely suppressed by inhibiting integrin α4/FAK expression. In addition, Val activated the cell cycle checkpoint CHK2 in response to excessive DNA damage, which led to the activation of caspase-3/9 and induced caspase-dependent apoptosis. Furthermore, the signaling cascades of the PI3K/AKT/mTOR and mitogen-activated protein kinase pathways were significantly inhibited by Val treatment. Taken together, our results indicate that Val can be used for the treatment of hypopharyngeal squamous cell carcinoma.

GaN기반 LED 응용을 AZO, Ni/AZO 및 NiOx/AZO의 전기적.광학적 특성

  • Ju, Dong-Hyeok;Lee, Hui-Gwan;Yu, Jae-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.249-249
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    • 2011
  • 투명전도성산화물(transparent conducting oxides, TCOs) 박막은 전기 전도성과 광투과성이 우수하여 유기발광다이오드(organic light-emitting diode, OLED), 태양전지(solar cell), 발광다이오드(LED) 등의 광전자 소자에 널리 응용되고 있다. 특히 LED에서 p-GaN층에서 전류가 층안에서 충분하게 확산되지 않기 때문에, TCO는 균일하게 전류를 흘려보내기 위해서 전류확산층(current spreading layer)으로 사용된다. 그 중 널리 쓰이는 산화인듐주석(indium tin oxide, ITO)은 고가의 indium가격과 인체에 유해한 독성 등이 문제점으로 지적되고 있다. 따라서 indium의 함량을 저감하거나 함유하지 않은 새로운 조성의 친환경적 대체 TCO 개발에 대한 연구가 많이 진행되고 있다. 이러한 반도체 재료 중 하나인 AZO (Al-doped zinc oxide, Al2O3 : 2wt.%)는 3.3 eV의 넓은 에너지 밴드갭을 가지며, 가시광선 및 근적외선 파장영역에서 높은 투과율을 나타낸다. 따라서 본 연구에서는 GaN기반 LED 응용을 위한 전류확산층으로 ITO 대신 AZO의 특성을 연구하였다. 박막 증착율이 높고, 제작과정의 조정이 용이한 RF magnetron 스퍼터를 이용하여 glass기판 위에 AZO, Ni/AZO, NiOx/AZO를 증착하였다. 이어서 $N_2$ 분위기에서 다양한 온도 조건에서 열처리(rapid thermal annealing, RTA)하여 전기적 광학적 특성에 대하여 비교 분석하였다.

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Effect of Steroid Hormones and Intracellular $Ca^{++}$ on Taurine Transporter Activity in Murine Macrophage Cell Line (마우스 대식세포에서 스테로이드 호르몬과 세포내 $Ca^{++}$ 타우린수송체의 활성에 미치는 영향)

  • 김하원;안혜숙;이선민;이은진;현진원;박건구;박태선;김병각
    • Biomolecules & Therapeutics
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    • v.9 no.1
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    • pp.40-45
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    • 2001
  • The activity of taurine transporter is affected by various extracellular stimuli such as ion, hormone and stress. To assess effects of steroid hormones antral cyclosporin A (CsA) on the taurine transporter activity, murine monocytic RAW264.7 cell line was stimulated with dexamethasone (DM), triamcinolone (TA), cortisone (CS), hydrocortisone (HCS), prednisone (PSN), prednisolone (PSL) and methylprednisolone (MPSL) in the presence of 12-0-tetradecanoylphorbol-13-acetate(TPA). Treatment of TPA on the cell line led to significant reduction of taurine transporter activity. However, in case of stimulation of the cells with steroid hormones in the presence of TPA, all of them recovered TPA-induced reduction of the taurine transporter activity. Treatment of the cells with CsA led to significant reduction of the taurine transporter activity. Ionomycin (IM) recovered the reduced taurine transporter activity by CsA, but failed in the presence of EDTA, a calcium chelating agent. These results showed that glucocorticoid hormone recovered TPA-induced reduction of taurine transporter activity and that IM recovered CsA-induced reduction of the transporter activity by increasing intracellular free $Ca^{++}$ concentration.n.

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The Current Situation for Recycling of Lithium Ion Batteries

  • Hiroshi Okamoto;Lee, Sang-Hoon
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.252-256
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    • 2001
  • The rapid development of communication equipment and information processing technology has led to a constant improvement in cordless communication. Lithium ion batteries used in cellular phones and laptop computers, in particular, have been in the forefront of the above revolution. These batteries use high value added raw materials and have a high and stable energy output and are increasingly coming into common use. The development of the material for the negative terminal has led to an improvement in the quality and efficiency of the batteries, whereas a reduction in the cost of the battery by researching new materials for the positive anode has become a research theme by itself. These long life batteries, it is being increasingly realized, can have value added to them by recycling. Research is increasingly being done on recycling the aluminum case and the load casing for the negative diode. This paper aims to introduce the current situation of recycling of lithium ion batteries. 1. Introduction 2. Various types of batteries and the situation of their recycling and the facts regarding recycling. 3. Example of cobalt recycling from waste Lithium ion secondary cell. 3-1) Flow Chart of Lithium ion battery recycling 3-2) Materials that make a lithium ion secondary cell. 3-3) Coarse grinding of Lithium ion secondary cell, and stabilization of current discharge 3-4) Burning 3-5) Grinding 3-6) Magnetic Separation 3-7) Dry sieving 3-8) Dry Classifying 3-9) Content Ratio of recycled cobalt parts 3-10) Summary of the Line used for the recovery of Cobalt from waste Lithium ion battery. 4. Conclusion.

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Advancements of Common Gamma-Chain Family Cytokines in Cancer Immunotherapy

  • Alexandra A. Wolfarth;Swati Dhar;Jack B. Goon;Ugonna I. Ezeanya;Sara Ferrando-Martínez;Byung Ha Lee
    • IMMUNE NETWORK
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    • v.22 no.1
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    • pp.5.1-5.22
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    • 2022
  • The approval of immunotherapies such as checkpoint inhibitors (CPIs), adoptive cell therapies and cancer vaccines has revolutionized the way cancer treatment is approached. While immunotherapies have improved clinical outcome in a variety of tumor types, some cancers have proven harder to combat using single agents, underscoring the need for multi-targeted immunotherapy approaches. Efficacy of CPIs and cancer vaccines requires patients to have a competent immune system with adequate cell numbers while the efficacy of adoptive cellular therapy is limited by the expansion and persistence of cells after infusion. A promising strategy to overcome these challenges is combination treatment with common gamma-chain cytokines. Gamma-chain cytokines play a critical role in the survival, proliferation, differentiation and function of multiple immune cell types, including CD8 T-cells and NK cells, which are at the center of the anti-tumor response. While the short halflife of recombinant cytokines initially limited their application in the clinic, advancements in protein engineering have led to the development of several next-generation drug candidates with dramatically increased half-life and bioactivity. When combining these cytokines with other immunotherapies, strong evidence of synergy has been observed in preclinical and clinical cancer settings. This promising data has led to the initiation of 70 ongoing clinical trials including IL-2, IL-7, IL-15 and IL-21. This review summarizes the recent advancements of common gamma-chain cytokines and their potential as a cancer immunotherapy.

The Photovoltaic LED Lighting System applying Lithium Polymer Batteries (리튬 폴리머 전지를 이용한 태양광 LED 조명시스템)

  • Ahn, In-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.2
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    • pp.109-115
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    • 2014
  • The research on solar energy that we get from nature to cope with energy exhaustion is a very significant and inevitable task for us to do. Along with this, lately, in Korea, as part of new growth engine industry regarding low-carbon green growth, we have selected the LED(Light Emitting Diode) as low power consuming, eco-friendly lighting equipment and have been facilitating research and development on it and creating a variety of new industries utilizing it. What was developed here in this research was the photovoltaic LED lighting system applying lithium polymer batteries equipped with the excellent performance of lithium ion batteries as well as significantly low explosive hazard. Its photovoltaic panel was made to have 100W capacity, and for its power supply system, functional convenience was considered so that it could be equipped with both DC and AC power to be used as household electricity in a variety of ways.

Cell differentiation control device capable of simultaneous stimulation of multi-wavelength LED (다파장 LED의 동시 자극 인가가 가능한 세포 분화 유도기)

  • Choe, Se-woon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.2
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    • pp.221-227
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    • 2021
  • Recently, interests in mask-type skin care devices using light-emitting diodes have been increasing and optical stimuli at certain wavelengths have been known to have various therapeutic effects, such as skin whitening, acne treatment, elasticity and wrinkle improvement by controlling the exposure to wavelengths of light and irradiation time. In particular, light sources of different wavelengths are applied in masks for the purpose of suppressing skin aging, inducing cell proliferation, and alleviating skin inflammation. In this paper, we developed a light-emitting diode control system that is actively used in skin regeneration masks using a microcontroller. Optical stimuli with different manners were applied to skin fibroblast cells in a single or complex wavelengths, and then confirmed how they are effective in the cell differentiation. In addition, we found a specific wavelength that has a positive effect on cell proliferation rates, and confirm the effectiveness of cell proliferation by image processing based quantitative analysis.