• Title/Summary/Keyword: varying thickness

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Characteristics of doping process with various wafer thicknesses for thin crystalline silicon solar cell application (박형 결정질 실리콘 태양전지 제작을 위한 웨이퍼 두께에 따른 특성 연구)

  • Jeong, Kyeong-Taek;Lee, Hee-Jun;Song, Hee-Eun;Yoo, Kwon-Jong;Yang, O-Bong
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.101-104
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    • 2011
  • Many studies in crystalline silicon solar cell fabrication have been focused on high efficiency and low cost. In this paper, we carried out the doping procedure by varying the silicon wafer thicknesses and sheet resistance. The silicon wafers with various thicknesses were obtained by shiny etching and texturing. The thicknesses of wafers were 100, 120, 150, and $180{\mu}m$. The emitter layer formed by $POCl_3$ doping process had sheet resistance with 40 and $80{\Omega}/sq$ for selective emitter application. This experiment indicated wafer thickness did not influence sheet resistance but lifetime was strongly effected.

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Development of Stress Indices for Trunnion Pipe Support (원통형 배관 지지대의 응력계수 개발)

  • 김종민;박명규;엄세윤;이대희;박준수
    • Computational Structural Engineering
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    • v.9 no.3
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    • pp.115-123
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    • 1996
  • A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized into the average (membrance) and the linearly varying(bending) stresses through the thickness. The resulting stresses are interpreted per Section III of the ASME Boiler and Pressure Vessel Code from which the Primary (B/sub 1/) and Secondary(C/sub 1/) stress indices for pressure, the Primary(B/sub 2R/, B/sub 2T/) and Secondary(C/sub 2R/, C/sub 2T/) stress indices for moment are developed. Several analyses were performed for various structural geometries in order to obtain empirical representation for the stress indices in terms of dimensionless ratios.

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Effects of Organic Thin Films on Local Resonance of Metamaterials under Photoexcitation

  • Song, Myeong-Seong;Hwang, In-Wook;Lee, Chang-Lyoul;Kang, Chul;Kee, Chul-Sik;Park, Sae June;Ahn, Yeong Hwan;Park, Doo Jae;Lee, Joong Wook
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.372-377
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    • 2017
  • We demonstrate that the local resonance of metamaterials can be tuned by the effects of organic thin films under photoexcitation. Tris (8-hydroxyquinolinato) aluminum ($Alq_3$) layers are deposited on metamaterial/silicon hybrid structures. By varying the thickness of the $Alq_3$ layer on the subwavelength scale, the resonant peak of the metamaterial becomes very adjustable, due to the effect of a thin dielectric substrate. In addition, under photoexcitation all the spectral peaks of the resonance shift to higher frequencies. This originates from the reduction of the capacitive response generated inside the gaps of split-ring resonators. The adjustability of the electromagnetic spectrum may be useful for developing optical systems requiring refractive-index engineering and active optical devices.

Simulation of Capillary Phenomenon for Solution Coating of High-uniformity Organic thin Films (고균일 유기박막 코팅을 위한 모세관 현상 전산모사)

  • Shin, Dong-Kyun;Hong, Gi-Young;Park, Jong-Woon;Seo, Hwa-Il
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.106-111
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    • 2017
  • When a substrate with a pixel-defining layer (bank) is coated, there arises capillary force due to surface tension and adhesive forces between a solvent and the bank layer. It brings in a degradation of film thickness and emission uniformities within pixels. With an attempt to suppress it, we have performed fluid flow simulations of capillary arise by varying the contact angle of bank and the bank structure. We have first demonstrated that the fluid flow model can reproduce the capillary phenomenon that was observed experimentally. It has been found that capillary arise can be suppressed using a hydrophobic material for the bank layer. Furthermore, it was suppressed by tilting the sidewalls outwardly (i.e., using a positive photoresistor). We can obtain very uniform films when the slope is $50^{\circ}$ with the contact angle of $40^{\circ}$.

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Dynamic Characteristics of Laminated Shells by Finite Strip Mehod (FSM에 의한 다층 원통쉘의 동적 특성에 관한 연구)

  • Park, Sungjin
    • Journal of the Society of Disaster Information
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    • v.11 no.4
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    • pp.534-541
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    • 2015
  • This study was presented how to interpret a laminated cylindrical shell having both ends supported condition are simple, and by identifying the three-dimensional stress characteristics. The governing equations were using the concept of finite element assuming the conversion into ordinary differential equations and partial differential equations by numerical analysis using the finite strip method. In particular, a function performed for the three-dimensional laminated cylindrical shell having a simple support condition were analyzed for the case composed of a specific function of the beam consisting of a trigonometric function. Layer material and layer thickness of a steel or concrete, the cylindrical length and the like by varying the parameters variously examine the effects of multi-layer cylindrical shell.

Quality Characteristics of Cookies Made with Added Wheat Sprout Powder (밀싹 분말을 첨가한 쿠키의 품질특성)

  • An, Sang-Hee
    • Korean journal of food and cookery science
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    • v.31 no.6
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    • pp.687-695
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    • 2015
  • The purpose of this study was to investigate the quality characteristics of cookies prepared with wheat sprout powder substituted at varying proportions (0%, 2%, 4%, 6%, and 8%) for wheat flour. The bulk density of cookie dough with wheat sprout powder were higher than that of the control group and the pH decreased. The moisture content of the groups with wheat sprout powder was higher than the control group. Width and thickness of finished cookies containing wheat sprout powder were lower than those of the control group. The spread ratio of the group with 8% wheat sprout powder was higher than that of the control group. In color, the L and a value decreased significantly with addition of wheat sprout powder. The hardness of the study groups was lower than that of the control group. DPPH radical scavenging activity of the control group was 24.90%, whereas the study groups ranged from 27.53~38.76%. Sensory evaluation scores in terms of appearance, texture, taste and overall preference of groups with 2% and 4% of wheat sprout powder did not show any significant difference when compared to the control group. Based on the above results, using less than 4% of the wheat sprout powder would be appropriate for use in cookies.

Dependence of Blue Organic Emitter Layer Thickness to Optical Property of 2-wavelength White Organic Light-emitting Diodes (청색 유기발광층 두께에 따른 2-파장 방식의 백색 유기발광 소자의 광학적 특성)

  • Park, Chan-Jun;Cho, Nam-Ihn;Song, Young-Wook
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.6
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    • pp.511-514
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    • 2008
  • 2-wavelength type white OLED devices have been made consisted of two layers; a layer with blue light emitting DPVBi host and other EML layer with yellow emitting rubrene dopant. New method to get white emitting device has been suggested by varying thicknesses of the DPVBi layer. The ITO/2-TNATA($150{\AA}$)/NPB($350{\AA}$)/DPVBi($35{\AA}$)/DPVBi:rubrene (2wt%,$200{\AA}$)/DPVBi($100{\AA}$)/Alq_3($50{\AA}$)/LiF($5{\AA}$)/Al($1000{\AA}$) structure has showed optimum results in CIE coordinates of (0.3233, 0.33). OLED devices with this structure has properties of $1.2d/m^2$ at turn-on voltage of 3.9V and $1037cd/m^2$ at 7.9V. This structure has advantages of simple fabrication and easy to emit the white color.

Preparation and Characterization of $Ge_{20}As_{20}Se_{60}$ Amorphous Chalcogenide Thin Film by Spin Coating (Spin-coating에 의한 $Ge_{20}As_{20}Se_{60}$ 비정질 chalcogenide 박막의 제조 및 광특성 분석)

  • 이강구;최세영
    • Journal of the Korean Ceramic Society
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    • v.37 no.3
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    • pp.219-226
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    • 2000
  • Amorphous Ge20As20Se60 chalcogenide thin films were prepared by spin coating technique from mixed solutions of As40Se60 and Ge40Se60 dissolved in ethylenediamine. Films were prepared at a roating speed of 3500 rpm and spinning time was 10 second and heat-treateed at 27$0^{\circ}C$ for 1 hour. The resulting film thickness and RMS roughness were approximately 340 nm and 15$\AA$. Photostructure changes were investigated with 514.5nm Ar+ laser irradiation and heat-treatment. After Ar+ laser irradiation, transmittance and transmission efficiency decreased respectively up to 24.9% at 2.43 eV and 67.5% at 3.27 eV, and absorption edge shifted toward long wavelength. Optical bandgap changed from 2.03 to 1.83 eV, and absoprtion coefficient and absorption efficiency increased up to 0.33$\times$105cm-1 at 3.37eV and 88.3% at 1.31 eV, respectively. These photodarkening state were recovered reversibly by heat-treatment at 27$0^{\circ}C$ for 1 hour. Photodarkening and thermal bleaching effects by laser irradiation and heat-treatment revealed reversible amorphous-to-amorphous transition varying only coordination number.

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Trend of hand dimensions for Koreans and Comparison with foreigners' data (한국인 손 치수의 추세 변동 및 외국 자료와의 비교)

  • Kee, Do-Hyung
    • Journal of Korean Institute of Industrial Engineers
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    • v.36 no.3
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    • pp.146-153
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    • 2010
  • The purposes of this are (1) to present representative five hand dimensions by measurement year, (2) to investigate hand characteristics based on relative ratios of varying hand dimensions and (3) to compare Korean hand dimensions to other countries' data. Comparing to those of 1979, statures of 2004 increased by 3.0~3.5%, while males' hand dimensions of hand length, medius finger length, hand circumference, hand breadth and hand thickness decreased by 2.0~5.0%. Ratios of hand dimensions to those of medius finger were not significantly different depending upon age group and gender, but were significantly different depending upon races of Korean and American. Hand lengths of Koreans were shorter by about 4.0% than those of Japanese irrespective of gender, while the other compared dimensions for Koreans were larger than those of Japanese. Hand dimensions used in this study of Koreans were generally smaller that those of Americans. It is recommended from this study that when designing hand relevant things including glove, computer keyboard, smart phone key pad, etc., the different hand characteristics found in this study be fully reflected to develop competitive products.

Effect of double pinning mechanism in BSO-added GdBa2Cu3O7-x thin films

  • Oh, J.Y.;Jeon, H.K.;Lee, J.M.;Kang, W.N.;Kang, B.
    • Progress in Superconductivity and Cryogenics
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    • v.19 no.3
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    • pp.13-17
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    • 2017
  • We investigated the effect of self-assembled BSO nano-defects as pinning centers in BSO-added GdBCO films when the thicknesses of films were varied. 3.5 vol. % BSO-added GdBCO films with varying thicknesses from 200 nm to 1000 nm were deposited on $SrTiO_3$ (STO) substrate by using pulsed laser deposition (PLD) process. For the films with thicknesses of 400 nm and 600 nm, 'anomaly shoulders' in $J_c-H$ characteristic curves were observed near the matching field. The anomaly shoulders appeared in the field dependence of $J_c$ may be attributed to the existence of double pinning mechanisms in thin films. The fit to the pinning force density as a function of reduced field h ($H/H_{irr}$) using the Dew-Hughes' scaling law shows that both the 400 nm- and the 600 nm-thick films have double pinning mechanisms while the other films have a single pinning mechanism. These results indicate that the self-assembled property of BSO result in different role as pinning centers with different thickness.