• Polymer(Korea)
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• v.36 no.6
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• pp.803-809
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• 2012

The non-isothermal crystallization behavior of ethylene-tetrafluoroethylene (ETFE) copolymer was investigated by DSC and imaging FTIR analysis. Modified non-isothermal Avrami analysis was applied to interpret the crystallization behavior of ETFE. It was found that the less linearity in ln[-ln(1-X(t))] vs. ln(t) plot was obtained in thermal analysis comparison with imaging FTIR due to relatively small crystallization enthalpy change in ETFE. It means that imaging FTIR measured by overall IR absorption intensity change due to the crystallization was found to be effective to understand the non-isothermal crystallization kinetics of ETFE. In addition, the optical transmittance of ETFE was studied. The crystallite developed by slow cooling caused the light scattering and resulted in the increase of haze and the lowering of transmittance up to 8%. From our results, it was confirmed that cooling rate is an important processing parameter for maintaining optical transmittance of ETFE as a replacement material for glass.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.171-176
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• 2009

Purpose : To investigate the effect of coating material in RF coil, which is one of main parts in MRI machine, on the Q-factor and SNR(signal-to-noise ratio) in MR images. Materials and Methods : RF coils with inner diameter of 1.7 mm were made by using copper wires coated with polyester, polyurethane, polyimide, polyamideimide, and polyester-imide, and by using copper wires in which coating materials had been removed. Q-factors of the RF coils were measured by network analyzer, and SNR values in the spin-echo MR images obtained by 600 MHz (14.1 T, Bruker DMX600) micro-imaging system for the coated and uncoated cases. Results : The measured SNRs were almost same for the RF coils with coat-removed copper wires, however SNRs and Q-factors were different for the coated cases depending on the coating material. They were maximized in the polyurethane-coated case in which the SNR was > 30% greater than polyester-coated case. Conclusion : We made solenoid-type RF coils which were easily used for MR micro-imaging in Bruker MRI probe. There was a significant coating-material dependence in the measured Q values and SNRs for the home-made RF coils. The study demonstrated that the choice of coating material of RF coil may be a critical factor in the MRI sensitivity based on SNR value.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.1
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• pp.13-19
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• 2008

Purpose : In sponge quality of the material in digital radiography environment coating because do position blocks two that do not become coating done positioning blocks two that do not become coating done positioning block and sponge quality of the material to testing bench image artifact's difference compare. Method of study : In digital radiography environment positioning block of different two products same sunshine or effect that image and positioning block artifact gents in image analyze. the target used positioning block 2 when examine hand, rib and examination condition did each differently according to used positioning block. reflex compared picture that do image and verify that examine first time. Result : 1. In sponge quality of the material coating in done product artifact appear. Did not appear in product that do not become coating. 2. Can know coating's existence, that artifact according to radish happens. 3. Quality of the material coating's existence, there was difference of slippage according to radish Conclusion : Quality of the material coating phenomenon that done positioning block thus, it may have to be considered that use after estimate degree that get in image.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.291-309
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• 2000

Statement of problem. There were several studies on the effects of irradiation to peri-implant bone tissue. However, no clear biological effect of irradiation on peri-implant bone tissue was reported yet. Purpose. This study compared the effect of irradiation on the surrounding tissue of a HA-coated implant fixture with controls. Material and methods. 6 Steri-Oss implants were implanted into the femur of 6 mongrels. The implanted dogs were divided into three groups and received irradiation. After 1 month, 2months and 4 months healing period, the histologic examination and mobility test and digital radiographic imaging analyses were performed to compare the control and experimental group respectively. Results. The irradiated group showed slower healing than control group in light microscopic observations. The mobility test demonstrated significant less number (Periotest) in control group than that of irradiated groups. The digital radiographic imaging analysis showed that the bone density of irradiated group was higher than control group. Conclusion. Generally, control group showed favorable biological response and less mobility than irradiated group. The conflict result of bone density value were measured by the digital radiographic imaging analysis. The digital radiographic imaging analysis needs more research in future.

• Transactions on Electrical and Electronic Materials
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• v.3 no.4
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• pp.16-20
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• 2002

The high bias voltage associated with the thick layer (typically 500-1000 ㎛) of selenium required to have an acceptable x-ray absorption in radiography and fluoroscopy applications may have some practical inconvenience. A hybrid x-ray detector with zinc sulfide-amorphous selenium structure has been developed to improve the x-ray sensitivity of a a-Se based flat-panel digital imaging detector. Photoluminescence(PL) characteristic of a ZnS:Ag phosphor layer showed a light emission peak centered at about 450 nm, which matches the sensitivity spectrum of selenium. The dark current of the hybrid detector showed similar characteristics with that of a a-Se detector. The x-ray sensitivity of hybrid and a-Se x-ray detector was 345 pC/㎠/mR and 295 pC/㎠/mR at an applied voltage of 10 V/㎛, respectively. The purpose of this study was to evaluate the pertinence of a solution using a thin selenium layer, as a photosensitive converter, with a thick coating of silver doped zinc sulfide phosphor.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.32-37
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• 2016

Sidewall angle (SWA) of an absorber stack in extreme ultraviolet lithography mask is considered to be $90^{\circ}$ ideally, however, it is difficult to obtain $90^{\circ}$ SWA because absorber profile is changed by complicated etching process. As the imaging performance of the mask can be varied with this SWA of the absorber stack, more complicated optical proximity correction is required to compensate for the variation of imaging performance. In this study, phase shift mask (PSM) is suggested to reduce the variation of imaging performance due to SWA change by modifying mask material and structure. Variations of imaging performance and lithography process margin depending on SWA were evaluated through aerial image and developed resist simulations to confirm the advantages of PSM over the binary intensity mask (BIM). The results show that the variations of normalized image log slope and critical dimension bias depending on SWA are reduced with PSM compared to BIM. Process margin for exposure dose and focus was also improved with PSM.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.202.2-202.2
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.133-136
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• 1998

The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. Here we report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films prepared by the Langmuir-Blodgett technique.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.269-272
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• 1996

The electrochemical behavior of Ru complex and PD complex monolayer, deposited on conductive substrate by the Langmuir-Blodgett(LB) technique as monolayer and multilayer, has been studied by cyclic voltammetry. Monolayer films show stable reversible state. Atomic resolution imaging of LB highly-conductive, environmently stable organic films has been obtained by atomic force microscopy (AFM) showing their closely packed structure,

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.10a
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• pp.82-85
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• 1988

In the present study, we have investigated a novel photothermal imaging technique in $80^{\circ}$ deposited Ge Se film which do not utilize silver and deposited a-$Ge_{25}Se_{75}$ films was measured with the exposure time and annealing time. The results showed that the maximum changing rate of thickness was 3% in exposured film and 14% in postexposure annealing film.