• 제목/요약/키워드: tube formation

검색결과 475건 처리시간 0.03초

스크린 인쇄법을 이용한 오실로스코프용 형광막 제조 기술 개발 (The Development of PHosphor Screen Formation For Oscilloscope Using Screen Printing Method)

  • 이미영;김영배;남수용
    • 한국인쇄학회지
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    • 제22권1호
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    • pp.53-64
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    • 2004
  • The CRT(cathode ray tube) in oscilloscope consists of an electron gun, horizontal vertical deflection system and a phosphor screen. When the electron beam strikes the phosphor screen, the phosphor generates light. The phosphor screen has formed by CRT precipitation method. But, this method has some defects that are complex process, low yield, much consumption of raw-material, dirty working environment, waste problem, require of high cost. Moreover phosphor for oscilloscope used at present has been imported from Japan. Therefore developments of new phosphor and new method(the screen printing) top form phosphor screen for oscilloscope are required to improve these matters. This study was developed novel method(the screen printing) to form the phosphor screen for oscilloscope used new phosphor. This screen printing method has advantages of simple process, high yield, clean working environment, saving raw material and running-cost.

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50kWth미분탄 연소 시스템에서 탄종별 슬래깅 및 파울링 특성 연구 (An Experimental Study on Slagging/Fouling Characteristics for Various Coals in a 50kWth Pulverized Coal Combustion System)

  • 강기섭;이재욱;채태영;류창국;양원
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.107-109
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    • 2012
  • In Korean coal power plants, rising coal prices have recently led to the rapid utilization of low lank coals such as sub-bituminous coal with low calorific values and low ash fusion temperatures. Using these coals beyond the design range has resulted in important issues including slagging and fouling, which cause negative effects in boiler performances and unstable operations. The purpose of this study is to observe slagging and fouling characteristics resulted from burning various ranks of pulverized coals. We have tested 3 different coals: FLAME(bituminous), KCH(sub-bituminous) and MOOLARBEN(bituminous)coals in the pilot system $50kW_{th}$ scale. A stainless steel tube with preheated air inside was installed in the downstream in order to simulate water wall. Collected ash on the probe and the slag inside the furnace near burner were analyzed by SEM (scanning electron microscopy) to verify the formation degree, surface features and color changes of the pasty ash particles. Induced coupled plasma and energy dispersive X-ray spectroscopy were also performed to figure out the chemical characteristics of collected samples. As a result, KCH was observed that more slag was developed inside the walls of the furnace and on the probe than the other two kinds of coals, as shown in the calculate slagging and fouling indices as well.

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TREATMENT OF FOODWASTE AND POSPHORUS REMOVAL USING STRUVITE CRYSTALLIZATION IN HYBRID ANAEROBIC REACTOR WITH SAC MEDIA

  • Park, In-Chul;Kim, Dong-Su;Kim, Sung-Man;Lee, Jung-Jun
    • 한국자원리싸이클링학회:학술대회논문집
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    • 한국자원리싸이클링학회 2001년도 정기총회 특별강연 및 춘계학술연구발표회(2)
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    • pp.129-132
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    • 2001
  • The purpose of this research was to understand possibility of foodwaste treatment by hybrid anaerobic reactor(HAR). The Possibility of methane utility and applicability of hybrid reactor system using foodwaste as substrate was investigated. The maximum loading rate and optimized operational conditions were determined. Hybrid anaerobic reactor was filled with packing material 50% of its total volume between the tube and the outer surface. The packing material used was randomly packed open-pore synthesis activated ceramic(SAC) media as support media for microbial attachment, growth, and chemical stability protected bacteria from effect of organic acid accumulation. In this research, although foodwaste has high concentrations C $l^{[-10]}$ and S $O_{4}$$^{2-}$ concentration the possibility of foodwaste anaerobic treatment was when foodwaste is treated by anaerobic digestion, this study focused on the possibility using C $H_4$ gas made under the anaerobic treatment as an alternative energy source. Other objective of this research is to study struvite formation and crystal forms in anaerobic digester. HAR is used to investigate phosphate crystallization without the addition of chemicals.

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VLSI를 위한 플라즈마 열적 질산화막의 형성 (Plasma Enhanced Thermal Nitridation of $SiO_2$ for VLSI)

  • 이재성;이용현;최시영;이덕동
    • 대한전자공학회논문지
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    • 제26권11호
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    • pp.1699-1705
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    • 1989
  • Nitridation of about 300\ulcornerSiO2 filmss thermally grown on Si was performed in NH3 plasm ambient (0.2-2 torr) at 900\ulcornerC-1100\ulcorner for 15-20 minutes. The peoperties of those films have been investigated by analyzing the AES and the SIMS data, and the results of the I-V and the C-V measurements. At the plasma ambient of less than 1.5 torr pressure, etching of the films have been shown. Above the 1.5 torr pressure, however, SiO2 films were nitrided as SiIxNy. Plasma thermal nitridation of SiO2 by addition of small amount (6%) of CF4 to the NH3 showed higher pile-up N concentration in the surface region of SiOxNy film. The higher the nitridation temperature is and the longer the nitridation time is the larger the dielectric constant is. The plasma thermal nitridation of silicon dioxide on silicon causes the flat-band voltage shift based on the formation of the positive charge. The conduction mechanism for SiOxNy films could be elucidated by Fowler-Nordheim tnneling model. By SIMS analysis, surface of the film nitrided in plasma process has less contamination than that of the film nitrided in open-tube process.

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내부 승저증(internal myiasis) 1례 (A human case of internal myiasis in Korea)

  • 정평림;정영헌
    • Parasites, Hosts and Diseases
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    • 제34권2호
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    • pp.151-154
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    • 1996
  • 저자 등은 1987넌에 인공 관막 치환수술을 받고 심방 내 혈전 형성을 예방하기 위하여 항응호제를 계속적으로 복용하여 오던 71세 남자가 우측 안면 및 상, 하지 운동 마비와 실어증을 주소로 1994년(9원 28일) 성남 인하병원에 입원하게 되었고 입원 11일째부터 사망하기까지 특수 유통식 공금을 위하여 위장 내로 투입한 비강 영양 튜우브(nasogastrictube)를 통하여 수 마리의 파리 유충(maggot)이 역류되어 나왔고, 구강 내에서도 총 45마리의 구더기가 발견된 증례를 경험하였다 이 파리 유충은 병균 11.5 mm 길이로서 걸정파리과(Calliphoridae) 금파리속(Lucllia)의 1종이었으며 위. 장관계에 병소를 갖고 있었음이 추정되었다. 본 내부 승저증(internal myiasis) 증례는 우리 나라에서 처음 보고되는 것이다.

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Comparison of the Effects of Nano-silver Antibacterial Coatings and Silver Ions on Zebrafish Embryogenesis

  • Yeo, Min-Kyeong;Yoon, Jae-Won
    • Molecular & Cellular Toxicology
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    • 제5권1호
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    • pp.23-31
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    • 2009
  • To compare the effects of nanometer-sized silver ions and support materials (nano-silver coating material, NM-silver) and silver ions, we exposed zebrafish embryos to both types of nano-silver ions and compared the acute responses during embryogenesis. The amount of silver in the NM-silver (17.16%) was greater than that in the silver ion (4.56%). Both of these materials have different atomic compositions. The silver ion-exposed groups (10 and 20 ppt) showed lower survival rates than the NM-silver-exposed groups (10 and 20 ppt). NM-silver penetrated the skin and blood tube of zebrafish larvae as aggregated particles, whereas, silver ions penetrated the organelles, nucleus and yolk in a spread-out pattern. Micro-array analysis of RNA from zebrafish larvae (72 hours post-fertilization) that were treated with either NM-silver or silver ions, showed alteration in expression of the BMP, activin, TGF-$\beta$, and $GSK3{\beta}$ genes pathway. Additionally, $GSK3{\beta}$ gene pathway for apoptosis that was related with left-right asymmetry. Gene expression changes in the NM-silver or silver ions-treated zebrafish embryo led to phenotypic changes in the hatched larvae, reflecting increased apoptosis and incomplete formation of an axis.

열병합/산업용 보일러 화로에서의 연소 해석 (Modeling of Combustion in Co-Generation / Industrial Boiler Furnace)

  • 김병윤;박부민;이경모
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.842-846
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    • 2001
  • Our company produces boilers for industrial usages or power plants. The aim of this study is to investigate the flame structure, heat transfer to evaporator tube wall and NOx emission in the furnaces. Also we are to derive correct FEGT(Furnace Exit Gas Temperature) characteristic curve. When we design furnace and superheater, economizer etc. FEGT characteristic curve is very important factor for optimum design. We calculated turbulent reacting flow, heat transfer and NOx emission in furnace by using numerical modeling with the help of commercial code. Three dimensional steady state calculation is done. k-e turbulence model and equilibrium chemistry combustion model with $\beta-probability$ density function is used. To calculate radiation heat transfer discrete ordinates model is used. And we measured FEGT at several operating plants. Measurement is done by R-type thermocouple. Radiation shield is attached to the thermocouple to prevent radiation effect. Measured and calculated results show good agreement. And we could understand the flame structure and NOx formation positions in each furnaces.

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Vibration of SWCNTs: Consistency and behavior of polynomial law index with Galerkin's model

  • Khadimallah, Mohamed A.;Hussain, Muzamal;Khedher, Khaled Mohamed;Bouzgarrou, Souhail Mohamed;Al Naim, Abdullah F.;Naeem, Muhammad Nawaz;Taj, Muhammad;Iqbal, Zafar;Tounsi, Abdelouahed
    • Advances in nano research
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    • 제9권4호
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    • pp.251-261
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    • 2020
  • In this article, vibration attributes of single walled carbon nanotubes based on Galerkin's method have been investigated. The influence of power law index subjected to different end supports has been overtly examined. Application of the Hamilton's variational principal leads to the formation of partial differential equations. The effects of different physical and material parameters on the fundamental frequencies are investigated for armchair and zigzag carbon nanotubes with clamped-clamped, simply supported and clamped-free boundary conditions. By using volume fraction for power law index, the fundamental natural frequency spectra for two forms of Single-Walled Carbon Nanotubes (SWCNTs) are calculated. The influence of frequencies against length-to-diameter ratios with varying power law index are investigated in detail for these tubes. MATLAB software package has been utilized for extracting tube frequency spectra. The obtained results are confirmed by comparing with available literature.

Use of Chitosan-TPP microsphere as a matrix for the encapsulation of somatic embryos of Capsicum annum var. grossum

  • Senarath, Wtpsk;Stevens, W.F.;Lee, Kui-Jae;Rehman, S.;Lee, Wang-Hyu
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
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    • pp.52-52
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    • 2002
  • Chitosan is a key compound of shrimp waste. It is a biopolymer, which is widely used in the field of medical Sciences. Chitosan-TPP (Tripolyphosphate) complex has more or less similar physical properties as Ca-alginate which can be used for the production of synthetic seeds. Possibility of the use of Chitosan-TPP complex as a matrix for encapsulation of somatic embryos was tested against the Ca-alginate complex (2.5w/v Na-alginate, 100mM CaCl2 at pH 5.5). Somatic embryos grown in the induction medium (IM) were drawn into the viscous chitosan solution (1%) and mixed well by inverting the tube carefully. Then the mixture was dropped at regular intervals into the tripolyphosphate (TPP) solution kept on a magnetic stirrer for bead formation. Synthetic seeds formed were washed and transferred into the incubation medium, then allowed either to air-dry or freeze-dry.(중략)

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Anti-Angiogenic Activities of Gliotoxin and 1ts Methylthio-Derivative, Fungal Metabolites

  • Lee, Hee-Jung;Lee, Jeong-Hyung;Hwang, Bang-Yeon;Kim, Hang-Sub;Lee, Jung-Joon
    • Archives of Pharmacal Research
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    • 제24권5호
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    • pp.397-401
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    • 2001
  • In the search for new naturally occurring angiogenic inhibitory we found that culture broths from two unidentified fungal strains exerted potent inhibitory activities on capillary-like tube formation of human umbilical vein endothelial cells (HUVEC) in vitro. Two active compounds were isolated by bioassay-guided separation and their structures were identified as gliotoxin (1) and its derivative methylthiogliotoxin (2) by spectroscopic analyses. These compounds significantly inhibited the migration of HUVEC assessed by in vitro wounding migration assay and exhibited at least 10 times more potent inhibition of proliferation of HUVECs as compared with that of cancer cell lines such as HeLa, MCF-7, and KB 3-1 cells. Especially, gliotoxin having disulfide group exerted more potent activities than methylthiogliotoxin, suggesting that gliotoxin could be a useful compound for further study as an anti-angiogenic agent.

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