• Title/Summary/Keyword: high uniformity

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Development of Dispenser System with Electrohydrodynamic and Voice Coil Motor for White Light Emitting Diode (백색 LED 제조를 위한 정전기력과 보이스코일모터를 이용한 디스펜서 시스템 개발)

  • Kang, Dong-Seong;Kim, Ki-Beom;Ha, Seok-Jae;Cho, Myeong-Woo;Lee, Woo-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6925-6931
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    • 2015
  • LED(Light Emitting Diode) is used in various filed like a display because of low power consuming, long life span, high brightness, rapid response time and environmental-friendly characteristic. General fabrication method is combination blue light LED chip with yellow fluorescent substance. Because this way is suitable for industry field in terms of convenience, economic, efficiency. In white light LED packaging process, encapsulation process that is dispensing fluorescent substance with silicon to blue light LED chip is most important. So, in this paper we develop EHD pump system using voice coil motor and electrostatic pump for dispensing fluorescent substance. For these things we conduct basic test about liquid surface profiles by voltage and process time. Through this data we decide optimal process condition and verify the optimal condition using design of experiment method. And to confirm uniformity of the condition, we conduct repeat dispensing test.

Practical Usability of Smoke Generator Containing Rice Chaff as a Combustible carrier (왕겨를 가연성 담체로 하는 훈연제의 실용성 연구)

  • Lim, He-Kyoung;Choi, Gyung-Ja;Park, No-Jung;Kim, Yong-Whan;Cho, Kwang-Yun;Yu, Ju-Hyun
    • Applied Biological Chemistry
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    • v.47 no.3
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    • pp.321-324
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    • 2004
  • Smoke rods were prepared for 2 insecticides and 5 fungicides using powdered rice chaff as a combustible carrier, and their burning characteristics were investigated. The distribution of active ingredient was investigated after the application of the granular smoke generator containing fenarimol in the connected vinyl plastic house growing cucumber. The protective effects of fungicide smoke generators were evaluated against cucumber gray mold (Botrytis cinerea) and tomato late blight (Phytophthora infestans), and compared with commercial wettable powders. Smoke rods containing powdered rice chaff showed high smoking rates of AI that were higher than commercial smoke pellets. The deposition of fenarimol on the ground of vinyl plastic house was $26.2{\pm}7.7\;ng/cm^2$ when averaged from 9 sites, and application uniformity was found. Also, the protective effects of 5 fungicidal smoke rods against plant diseases were so similar to the commercial wettable powders with no phytotoxicity that smoke rod formulations containing rice chaff as a combustible carrier could be used as an effective formulation for pesticides.

Meauring Method of Magnetic Particles' Coercivity Distribution and Its Applications (자성분말의 보자력 분포도 측정방법과 그 응용)

  • 홍양기;박상준;정홍식
    • Journal of the Korean Magnetics Society
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    • v.5 no.3
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    • pp.216-221
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    • 1995
  • Both manufacturing parameters and particles' chemical composition controll coercivity and its distribution of magnetic particles. The coercivity and its distribution are important properties for high density magnetic recording, so these are used as tool for evaluation of reproducibility of magnetic particles. We report in this paper the applications of dM/dH versus H curve, which is derived from magnetic hysteresis loop, to the evaluation of coercivity distribution of magnetic particles and oxidation studies of recording metal particles. The coercivity distri-bution can be estimated from the full width half rnaximun (FWHM) and the peak shape of the dM/dH versus H curve. The peak shape of the curve depends upon distribution of particles' coercivity. The peak of dM/dH versus H curve becomes broad and lor is splitted into two or rmre peaks. It depends on uniformity of particles' coercivity. When the coercivity difference between Ba-Ferrite and ${\gamma}-Fe_{2}O_{3}$ is larger than 600 Oe, the peak becomes broad and is consequently splitted into two peaks. Ununiformly substituted Ba-Ferrite particles show broad peak. It is apparent that the analysis of the curve is one of sensitive measuring techniques for determination of coercivity distri-bution and studies on magnetic properties of substituted Ba-Ferrite and oxidation of magnetic recording metal particles.

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Texture Feature Analysis Using a Brain Hemorrhage Patient CT Images (전산화단층촬영 영상을 이용한 뇌출혈 질감특징분석)

  • Park, Hyonghu;Park, Jikoon;Choi, Ilhong;Kang, Sangsik;Noh, Sicheol;Jung, Bongjae
    • Journal of the Korean Society of Radiology
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    • v.9 no.6
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    • pp.369-374
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    • 2015
  • In this study we proposed a texture feature analysis algorithm that distinguishes between a normal image and a diseased image using CT images of some brain hemorrhage patients, and generates both Eigen images and test images which can be applied to the proposed computer aided diagnosis system in order to perform a quantitative analysis for 6 parameters. And through the analysis, we derived and evaluated the recognition rate of CT images of brain hemorrhage. As the results of examining over 40 example CT images of brain hemorrhage, the recognition rates representing a specific texture feature-value are as follows: some appeared to be as high as 100% including average gray level, average contrast, smoothness, and Skewness while others showed a little low disease recognition rate: 95% for uniformity and 87.5% for entropy. Consequently, based on this research result, if a software that enables a computer aided diagnosis system for medical images is developed, it will lead to the availability for the automatic detection of a diseased spot in CT images of brain hemorrhage and quantitative analysis. And they can be used as computer aided diagnosis data, resulting in the increased accuracy and the shortened time in the stage of final reading.

Studies on the Nucleation of CVD Tungsten on the TiN substrate (TiN 기판상에서의 CVD텅스텐의 핵생성에 관한 연구)

  • Kim, Eui-Song;Lee, Chong-Mu;Lee, Jong-Gil
    • Korean Journal of Materials Research
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    • v.2 no.2
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    • pp.110-118
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    • 1992
  • When CVD-W films deposited on the reactively sputter-deposited TiN(${\circled1}$), the $NH_3$-RTP (rapid themal processed) TiN(${\circled2}$), and the furnace-annealed TiN submitate (${\circled3}$) by $SiH_4$, reduction, deposition rate is in the order of ${\circled1}>{\circled2}>{\circled3}$ and incubation period of W nucleation is in the order of ${\circled1}{\leq}{\circled2}<{\circled3}$. The longest incubation period of nucleation and lowest deposition rate for the CVD-W on the annealed TiN is due to the incorporation of oxygen from the nitrogen ambient containing some oxygen as contaminant into the TiN film. The higher W deposition rate and the lower incubation period of W nucleation on the RTP-TiN substrate in comparison with those on the sputtered TiN substrate seem to be due to a negative effect of the high compressive stress of the RTP-TiN on the nucleation and growth of W. Also the thickness uniformity of the W film deposited on the TiN substrate by $SiH_4$ reduction turns out to be better than that by $H_2$ reduction.

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New Phalaenopsis 'Sweet Pinky' of Dark Pink Medium Petal with Fragrance (향기가 있는 진분홍색 중형 팔레놉시스 'Sweet Pinky' 육성)

  • Joung, Hyang-Young;Lee, Young-Ran;Kim, Mi-Seon;Lim, Jin-Hee;Shin, Hak-Ki;Cho, Hae-Ryong;Rhee, Hae-Kyung;Park, Sang-Kun
    • Horticultural Science & Technology
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    • v.28 no.5
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    • pp.899-901
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    • 2010
  • 'Sweet Pinky' was developed by National Institute of Horticultural & Herbal Science in 1995. The seedling materials, obtained after selfing of dark pink medium variety 'Pinglong' from 1996 to 2002, were cultivated to 169 seedling lines. The dark pink medium-phalaenopsis '95-183-54' was selected for excellent fragrance and branching habit by individual selection. The selected line was multiplicated and the growth characteristics were investigated for the first examination from 2003 to 2007. It was named as 'Wonkyo F2-17' in 2008 and investigated for the second examination of growth characteristics. The examination was executed for stability, uniformity, yearly reproductibility, and public fancy. It was selected as a high quality cultivar with sweet fragrance and excellent branching habit from the selection council of new cultivars for agricultural products; thereafter, it was registered as variety 'Sweet Pinky' in 2008.

Interconnection Fee or Access fee? - Focusing on ISP-CP settlement dispute - (상호접속료인가, 망 이용대가인가? - ISP-CP간 망 연결 대가 분쟁 중심으로 -)

  • Cho, Dae-Keun
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.9-20
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    • 2020
  • This study redefines the networks' connection behaviors and the terms confusion over the settlement in Netflix-SK Broadband's dispute through domestic and foreign legal references. Conflict parties, academics and the media use the terms "interconnection fee" or "Access fee" without uniformity, and in some cases mixes for strategic purposes. The use of different terms for the same phenomenon (or vice versa) has a high need for research in that it makes it difficult to reach a unified approach to the problem, to discuss it productively and rationally, and, moreover, to resolve disputes. Therefore, this study cross-referenced/analyzed terms related to network utilization and connectivity, namely "Use", "Access", "Interconnection" and thus cost-related terms as a counter-pay. In addition, it suggests that interconnection fees and access fees should be used separately, and allows them to function as a starting point in resolving future ICT sector issues. As a result of this study, the price against the network access/use between Netflix and SK Broadband is access fee or retail price, and proposes to be used uniformly in the term "interconnection fee" only for fees incurred in interconnection between ISPs that possess or operate networks.

Characterization of Cold Hollow Cathode Ion Source by Modification of Electrode Structure (전극 구조 변화에 따른 Cold Hollow Cathode Ion Source의 특성 변화)

  • Seok, Jin-Woo;Chernysh, V.S.;Han, Sung;Beag, Young-Hwoan;Koh, Seok-Keun;Yoon, Ki-Hyun
    • Journal of the Korean Ceramic Society
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    • v.40 no.10
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    • pp.967-972
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    • 2003
  • The inner-diameter 5 cm cold hollow cathode ion source was designed for the high current density and the homogeneous beam profile of ion beam. The ion source consisted of a cylindrical cathode, a generation part of magnetic field, a plasma chamber, convex type ion optic system with two grid electrode, and DC power supply system. The cold hollow cathode ion sources were classified into standard type (I), electron output electrode modified type (II). The operation of the ion source was done with discharge current, ion beam potential and argon gas flow rate. The modification of electron output electrode resulted in uniform plasma generation and uniform area of ion beam was extended from 5 cm to 20 cm. Improved ion source was evaluated with beam uniformity, ion current, team extraction efficiency, and ionization efficiency.

Growth of GaAs/AlGaAs Superlattice and HEMT Structures by MOCVD (MOCVD에 의한 GaAs/AlGaAs 초격자 및 HEMT 구조의 성장)

  • Kim, Moo-Sung;Kim, Yong;Eom, Kyung-Sook;Kim, Sung-Il;Min, Suk-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.2
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    • pp.81-92
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    • 1990
  • We developed the technologies of wuperlattice and HEMT structures grown by MOCVD, and their characterization. In the case of GaAs/AlGaAs superlattice, the periodicity, interface abruptness and Al compositional uniformity were confirmed through the shallow angle lapping technique and double crystal x-ray measurement. Photoluminesence spectra due to quantum size effect of isolated quantum wells were also observed. The heterojunction abruptness was estimated to be within 1 monolayer fluctuation by the analysis of the relation between PL FWHM(Full Width at Half Maximum) and well width. HEMT structure was successfully grown by MOCVD. The 2 dimensional electron gas formation at heterointerface in HEMT structure were evidenced through the C-V profile, SdH (Shubnikov-de Haas)oscillation and low temperature Hall measurement. Low field mobility were as high as $69,000cm^2/v.sec$ for a sheet carrier density of $5.5{\times}10^{11}cm^-2$ at 15K, and $41,200cm^2/v.sec$ for a sheet carrier density of $6.6{\times}10^{11}cm^-2$ at 77K. In addition, well defined SdH oscillation and quantized Hall plateaues were observed.

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Formation of Size-controllable Ag Nanoparticles on Si Substrate by Annealing (크기 조절이 가능한 은 나노입자 형성을 위한 박막의 열처리 효과)

  • Lee, Sang Hoon;Lee, Tae Il;Moon, Kyeong-Ju;Myoung, Jae Min
    • Korean Journal of Materials Research
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    • v.23 no.7
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    • pp.379-384
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    • 2013
  • In order to produce size-controllable Ag nanoparticles and a nanomesh-patterned Si substrate, we introduce a rapid thermal annealing(RTA) method and a metal assisted chemical etching(MCE) process. Ag nanoparticles were self-organized from a thin Ag film on a Si substrate through the RTA process. The mean diameter of the nanoparticles was modulated by changing the thickness of the Ag film. Furthermore, we controlled the surface energy of the Si substrate by changing the Ar or $H_2$ ambient gas during the RTA process, and the modified surface energy was evaluated through water contact angle test. A smaller mean diameter of Ag nanoparticles was obtained under $H_2$ gas at RTA, compared to that under Ar, from the same thickness of Ag thin film. This result was observed by SEM and summarized by statistical analysis. The mechanism of this result was determined by the surface energy change caused by the chemical reaction between the Si substrate and $H_2$. The change of the surface energy affected on uniformity in the MCE process using Ag nanoparticles as catalyst. The nanoparticles formed under ambient Ar, having high surface energy, randomly moved in the lateral direction on the substrate even though the etching solution consisting of 10 % HF and 0.12 % $H_2O_2$ was cooled down to $-20^{\circ}C$ to minimize thermal energy, which could act as the driving force of movement. On the other hand, the nanoparticles thermally treated under ambient $H_2$ had low surface energy as the surface of the Si substrate reacted with $H_2$. That's why the Ag nanoparticles could keep their pattern and vertically etch the Si substrate during MCE.