• Title/Summary/Keyword: Material thickness

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Reduction of Exposure Dose of Mammography by Comparison of Compression Paddle Material (압박대 재질 비교를 통한 유방촬영의 피폭선량 감소 방안)

  • Hong, Dong-Hee
    • Journal of radiological science and technology
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    • v.42 no.6
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    • pp.455-460
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    • 2019
  • This study compared the radiation transmission and image quality of polymethylmethacrylate (PMMA), polycarbonate (PC), and carbon, which are common components of the compression plates currently used during breast imaging. In addition to measuring the transmitted dose and the intensity without the use of a compression paddle, the four different compression paddles were evaluated according to the material and thickness of each paddle. Radiation transmittance, maximum intensity, and plot profile type w ere all evaluated for each material, and for each factor evaluated the follow ing order w as noted, from best to w orst: carbon 4 mm, PMMA 3 mm, PMMA 4 mm, and PC 4 mm. It is necessary to study a variety of materials and thicknesses in order to find the optimal combination of material and thickness, because not only does the material have a large influence in reducing the radiation exposure during mammography, but the thickness of the compression plate also has a great influence.

A Study on Bow of Silicon Solar Cell by Soldering Different Thickness of Ribbon (리본 두께에 따른 태양전지 Bowing현상 연구)

  • Yoon, Na-Ri;Jung, Tae-Hee;Shin, Jun-Oh;Kang, Ki-Hwan;Ahn, Hyeung-Ken;Han, Deuk-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.68-68
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    • 2010
  • To reduce PV manufacturing costs, the thickness of solar cell is getting thinner. Bow is shown after cooling down the temperature of solder cell. It happens because of different thermal expansion coefficients of different metals. Bowed cell can make micro crack while module processing and it can drop off efficiency of PV module. As thinner solar cell is produced, the thickness of ribbon should be concerned to prevent extra bow. In this paper we investigate the contrast of deflection when we solder different thickness of ribbons on same solar cell. This approach would help to find out the optical thickness of ribbon for particular thickness of solar cell later on.

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Effect of Solvent Mixture Ratio on Rheology Property of Slurry and Thickness Control of Ceramic Green Sheets (유기 용매 혼합비에 따른 슬러리의 유동 특성과 세라믹 그린 쉬트의 두께 제어)

  • Kim, Jun-Young;Kim, Seung-Taek;Park, Jong-Chul;Yoo, Myong-Jae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.3
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    • pp.236-241
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    • 2008
  • The effect of organic solvent mixture ratio on the rheology property of slurry and thickness control of ceramic green sheet was investigated. For selecting a suitable dispersant multiple light scattering method was used to evaluate the particle migration velocity and variation of clarification layer thickness. Using the selected dispersant the dispersion property of solution according to solvent mixture ratio was investigated. Binder and plasticizers were added to formulate slurries and their viscosity was evaluated according to solvent mixture ratio. Ceramic green sheets with average thickness of 30, 50 urn were fabricated via tape casting and their thickness tolerances measured. As a result according to solvent mixture ratio the solution and slurry properties varied and for the mixture ratio of ethanol/toluene of 80/20 the ceramic green sheet with the lowest thickness tolerance was obtained.

Thickness dependence of the piezoelectric characteristic for PZT films using by rf magnetron sputtering (RF 마그네트론 스퍼터링으로 증착한 두께에 따른 PZT 박막의 강유전 특성에 관한 연구)

  • Lee, Tae-Yong;Park, Young;Song, Joon-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.313-316
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    • 2003
  • The lead zirconate titanate, $Pb(Zr_{0:52}Ti_{0:48})O_3$, films of $0.5\;{\mu}m,\;1\;{\mu}m$ and $2\;{\mu}m$ thickness were fabricated on $Pt/Ti/SiO_2/Si$ substrate by the rf magnetron sputtering method. The PZT films were annealed using by a rapid thermal annealing (RTA) method. The thickness dependence of the film structure, dielectric properties, Polarization-electric field hysteresis loops and capacitance-voltage characteristics were investigated over the thickness range of $0.5\;{\mu}m,\;1\;{\mu}m$ and $2\;{\mu}m$. According to the XRD patterns of the films, (110) peak intensity increases with film thickness increased. The increase of PZT films thickness leads to the decrease of the remanent polarization and the dielectric constant.

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A study on the change of material width by forging processing in fine pitch connector of C5210-H(HP) and NKT322-EH materials (C5210-H(HP)와 NKT322-EH 소재의 협피치 커텍터에서 단조 가공에 의한 소재 폭 변화에 관한 연구)

  • Shin, Mi-Kyung;Lee, Chun-Kyu
    • Design & Manufacturing
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    • v.14 no.3
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    • pp.17-22
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    • 2020
  • As devices such as smartphones, tablet PC, and wearable devices have been miniaturized, the connectors that go into the devices are also designed to be very small. The connector combines the plug and the receptacle to transfer electricity. As devices are miniaturized, the contact shape is formed by partially thinning the thickness of the raw material of the terminal in order to lower the coupling height of the plug and receptacle. The product used in this study is a receptacle terminal used for 0.4mm pitch board to board connector among fine pitch connectors. When the material thickness is reduced by forging the receptacle terminal, the width change of the pin is checked. To reduce the thickness of the material by forging, pre-notching is applied in the first step, forging in the second step, and notching in the third step. After forming the width dimension of the pin to 0.28 mm in the pre-notching process, in the forging process, the material thickness 0.08 mm and 0.02 mm (25%) were forged and the thickness was changed to 0.06 mm and the width change amount of the pin was measured. The facility produced 10,000 pieces at 400 SPM using a Yamada Dobby (MXM-40L) press, and thirty pins were measured and the average value was shown. After forging by using C5210-H (HP) and NKT322-EH, which are frequently used in connectors, analyze the amount of change in each material. The effect of punching oil on forging is investigated by appling FM-200M, which is highly viscous, and FL-212, fast drying oil. This study aims to minimize mold modification by predicting the amount of material change after forging.

Research for Thickness Change of Denture Base in Flask when Injecting Valplast Flexible Partial Denture Resin (발플라스트 레진 주입 시 발생되는 의치상의 두께변화에 관한 연구)

  • Jang, Wan-Young;Kim, Bu-Sob;Chung, In-Sung
    • Journal of Technologic Dentistry
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    • v.30 no.2
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    • pp.47-56
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    • 2008
  • This is a research for thickness change of denture base according to the shape of sprue & investment position of denture base in flask when injecting polyamid base resin for flexible partial denture as a part of study for Valplast among the flexible partial denture with a nylon base. It has been introduced several kinds of flexible partial denture product with a nylon base, but Valplast is the most widely used product among them. Valplast has been the most generally used material today since developed in 1950s in the United States as a material for flexible partial denture. Valplast is much more aesthetic than general metal-acrylic partial denture due to its translucent pink color and biocompatibility in terms of material characteristic. It keeps its flexibility for a long time after production, imposes a less burden on the teeth used as abutment, and it can be easily insert and remove due to its particular suppleness. Moreover, it is felt like real teeth more than metal-acrylic partial denture when being put in and takes alveolar bone under good protection since it receives occlusal force equally under the denture base. The most outstanding feature of Valplast is flexibility. The extent of its flexibility is determined by width & thickness of denture base. Considering general working procedure of Valplast, it can be seen that the thickness of denture base formed out of wax is increasing by the pressure while injecting resin. This research is to decide and test on the thickness increasing of Valplast by injecting pressure and the hypothesis upon that and is to prepare the basis estimating the increasing extent of thickness of denture base on the basis of the test result. In this test, it is expected occlusal malposition & thickness increasing of denture base by injecting pressure according to 4 kinds of test data which are to select 3 types of sprue method settling the forefront position at which the test material of fixed standard can be invested and to position the test material at the rearmost part keeping the minimum distance to set sprue. For 4 kinds of injecting test by investment position & sprue type, 20 test materials, 5 for each test were produced and a pressure of 1,180Kg was given with automatic injector of air cylinder type. The results are as follows: 1. For the amount of thickness increasing of denture base by investment position, the thickness of front investment is less increasing than the one of rear investment. 2. For the amount of thickness increasing of denture base by sprue type, the thickness of straight decompression sprue type which can absorb the injecting pressure after injecting polyamide base resin is less increasing than the other sprue types.

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An Experimental Study on Placements and Thickness of Damping Material for Vibration Control of Automotive Roof (자동차 루프의 진동제어를 위한 제진재의 위치 및 두께에 대한 실험적 연구)

  • Lee, Jeong-Kyun;Kim, Chan-Mook;Sa, Jong-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.31-37
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    • 2005
  • This paper presents an experimental study on vibration characteristics of an automotive roof with damping material. The goal of the study is to extract modal parameters(natural frequency, loss factor, and mode shape) of automotive roof with damping materials treatment. To determine the effective positions and thickness of the damping material on a roof, vibration tests have been carried out for six cases; an aluminum plate with damping material on maximum strain energy positions, and an aluminum plate with damping material on nodal lines. From the result of aluminum plate, it is found that the damping material should be placed on the location with maximum strain energy part. For the automotive roof, patches of constrained damping material, which has two different density, have been attached to the positions of the maximum strain energy with four kinds of thicknesses. This paper shows that the proper positioning of the damping material is very important and the effective thickness is about twice that of the roof panel.

The Optical Properties of Sb2O3/Na3AlF6/Sb2O3/Cr Multi Layered Thin Films by EMP Simulation (EMP시뮬레이션을 활용한 Sb2O3/Na3AlF6/Sb2O3/Cr 다층박막의 광 특성)

  • Kim, Jun-Sik;Jang, Gun-Eik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.4
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    • pp.376-380
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    • 2008
  • The optical properties of multi layered thin films with $Sb_2O_3/Na_3AlF_6/Sb_2O_3/Cr$ were simulated by using EMP(Essential Macleod Program). EMP is a comprehensive software package to design and analyse the optical characteristics of multi-layered thin film. $Sb_2O_3$ and $Na_3AlF_6$ were selected as a high refractive index and low refractive index material respectively. Additionally Cr was chosen as mid reflective material. Optical properties including color effect were systematically studied in terms of different optical thickness of low refractive index material. The optical thickness of $Na_3AlF_6$ was changed as 0.25, 0.5, 0.75 and $1.0\lambda$. The film with 0.25, 0.5, 0.75 and $1.0\lambda$ of optical thickness showed mixed color range between purple and red range, yellowish green and bluish green, purple and mixed color range of green and purple respectively.

A Study on the Crack Growth Behavior of a Inclined Crack in a Non-Uniform Thickness Material (두께가 일정하지 않은 재료에서 경사진 균열의 성장거동에 관한 연구)

  • 조명래;표창률;박종주;고명훈
    • Journal of the Korean Society of Safety
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    • v.12 no.4
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    • pp.27-38
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    • 1997
  • The effect of geometry factors on the combined mode stress intensity factor behaviors of a slant crack in a non-uniform thickness material was analysed by 2-dimensional theoretical analysis. The analysis is based on the Laurent's series expansions of complex potentials where the complex coefficients of the series are determined from the compatibility and the equilibrium conditions of the thickness interface and the stress free conditions of the crack surface. In numerical calculations the perturbation technique is employed. The expressions for the crack tip stress intensity factor are given in the form of power series of dimensionless crack length $\lamda$, and the function of crack slant angle $\alpha$ and thickness ratio $\beta$. The results of numerical calculations for each problems are represented as the correction factors F($\lamda$, $\alpha$, $\beta$). The results clearly show the following characteristics : The correction factors of the combined mode stress intensity factors for a non-uniform thickness material can be defined in the form of F($\lamda$, $\alpha$, $\beta$). The stress intensity factor values for a given crack length are decreased with increase of thickness ratio $\beta$.

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Study on Optimization of the Vacuum Evaporation Process for OLED (Organic Electro-luminescent Emitting Display) (유기EL 디스플레이의 진공 성막 공정의 최적화에 관한 연구)

  • Lee, Eung-Ki
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.1
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    • pp.35-40
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    • 2008
  • In OLED vacuum evaporation process, the essential requirements include good uniformity of the film thickness over a glass substrate. And, it is commercially significant to improve the consuming efficiency of material of the evaporant which is deposited on the substrate because of high price of organic materials. In this paper, to achieve the better thickness uniformity and the better organic material consuming rate, a process optimization algorithm was developed by understanding vacuum evaporation process parameters that affect the material consuming efficiency and the uniformity of film thickness. Based on the method developed in this study, the vacuum evaporation process of OLED was successfully controlled. The developed method allowed the manufacture of high quality OLED displays with cheaper fabrication cost.

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