• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.295-298
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• 2003

The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-$B_2O_3-V_2O_5$. DTA, XRD and SEM were used to study and characterize BaO-ZnO-$B_2O_3-V_2O_5$ glasses. PbO free paste developed at this paper has thermal expansion of $74{\times}10^{-7}/^{\circ}C$, DTA transformation point of $460^{\circ}C$, and firing condition of $560^{\circ}C$, 10min.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.524-525
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• 2005

The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system $ZnO-B_2O_3-Bi_2O_3-SiO_2$, DTA, and XRD were used to characterize $ZnO-B_2O_3-Bi_2O_3-SiO$ glasses. In this present study, PbO free paste had thermal expansion of $74\times10^{-7}/^{\circ}C$, DTA transformation point of $470^{\circ}C$, and firing condition of $540^{\circ}C$, 20min.

• 열처리공학회지
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• 제21권4호
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• pp.189-198
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• 2008

The production of automotive chassis parts requiring both high hardness and good shape-holdability is better realized by using press quenching technology, comprising the austenitizaton and the subsequent press quenching in a specially designed stamping tool. The effect of press quenching mold shape on the hardness distribution, bending height, and degree of planeness of automotive flexible plate during press quenching and tempering has been investigated. The preferable shape of the projections of punch and die in contact with the flexible plate was close to oval to improve the flow of cooling oil, leading to the higher hardness. The press quenching mold with three separate parts was more effective to control the dimensional change due to thermal deformation during press quenching. Some decrease in the bending height during tempering may be related to some recovery of the residual stress at $400^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.94-98
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• 1996

The x-ray diffraction experiments were carried out to investigate the phase transformation of the sputter-deposited Ag-In-Sb-Te optical thin films after rapid thermal annealing and while being annealed with high-temperature x-ray attachment. The formation mechanism of the reported mixed phase, with both amorphous phase and fine crystalline AgSbTe2 phase, of Ag-In-Sb-Te system in its ordered state was explained. Moreover the characteristics of the other phases which appear during the annealing processes were also discussed in the present article.

• Structural Engineering and Mechanics
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• 제90권3호
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• pp.263-272
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• 2024

This research deals with the study of two-dimensional deformation in transversely isotropic thermoelastic diffusion medium. This investigation integrates the effect of diffusion and thermal effects in transversely isotropic thermoelastic solids under inclined load. Inclined load is taken as linear combination of normal load and tangential load. Laplace and Fourier transformation techniques are employed to transform the physical domain and then transformed solutions are inverted with the aid of numerical inversion techniques. Concentrated and distributed load are considered to exemplify its utility. Graphical representation of variation in displacement, stresses, temperature and concentration distribution with distance is depicted by taking inclination at different angles. Some particular cases are studied.

• 한국축산식품학회지
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• 제40권4호
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• pp.588-600
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• 2020

The effect of age (22, 30, 38, and 46 days) on Beijing duck breast myosin gels was investigated. The results showed that the water holding capacity (WHC) and gel strength were markedly improved at the age of 30 days. Differential scanning calorimetry suggested that the myosin thermal ability increased at the age of 30 and 38 days (p<0.05). A compact myosin gel network with thin cross-linked strands and small regular cavities formed at the age of 30 days, which was resulted from the higher content of hydrophobic interactions and disulfide bonds. Moreover, the surface hydrophobicity of myosin extracted from a 30-day-old duck breast decreased significantly under temperature higher than 80℃ (p<0.05). This study illustrated that myosin extracted from a 30-day-old duck's breast enhanced and stabilized the WHC, thermal stability and molecular forces within the gel system. It concluded that age is an essential influencing factor on the myosin thermal stability and gel quality of Beijing duck due to the transformation of fibrils with different myosin character.

• 한국결정성장학회지
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• 제8권1호
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• pp.83-90
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• 1998

Li, K과 Na-흑연 층간화합물의 stage 전이 특성을 탄소층사이에 존재하는 intercalants의 deintercalation 메카니즘을 고려하여 제시하였다. 온도와 압력을 조절하여 합성된 Li-GICs(graphite intercalation compounds)를 분위기하에서 자발적으로 분해시켰다. 이들 화합물을 XRD 분석한 결과 1, 2 stage의 d001-값이 각각 3.71, 7.06 $\AA$으로 나타났다. 분위기하에서 Li-GiCs를 deintercalation 반응을 시킨 6주 후에 잔유화합물이 형성됨을 알 수 있었다. 또한, two-bulb 법으로 K-GICs를 합성하였으며, K-GDICs(graphite deintercalation compounds)의 구조적 안정성과 stage 전이에 대하여 조사하였다. X-선회절 결과로부터 K-GDICs는 10주 동안 안정한 K-흑연 잔유 화합물을 형성하였다. 그리고 고온, 고압법을 이용하여 합성된 1, 2stage의 Na-GICs의 deintercalation 반응과 열적 안정성에 대한 온도 의존성에 대하여 논하였다. 열적 안정성과 관련하여 Na-GICs의 구조변화를 XRD에 의하여 확인하였다. 이들 과정에 따르면 stage 전이는 무질서한 stage를 가진 GDICs의 불규칙적인 deintercalation에 의하여 형성됨을 제시할 수 있었다.

• 센서학회지
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• 제3권2호
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• pp.74-80
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• 1994

Silicon direct bonding 기술은 잔류 응력이 없고, 안정한 특성을 가진 센서의 제작과 silicon-on-insulator 소자의 제조에 널리 이용되고 있다. SDB의 공정 절차는 크게 실리콘 웨이퍼의 수산화 공정 과정과 wet oxidation fumace에서 고온의 열처리 공정 과정을 거치게 된다. 수산화 공정을 행한 후, Fourier transformation-infrared spectroscopy를 사용하여 실리콘 웨이퍼 표면을 분석하여 보면, 실리콘 웨이퍼의 표면에서는 수산화기가 생성됨을 알 수 있다. 실험 결과, $H_{2}O_{2}\;:\; H_{2}SO_{4}$ 용액을 사용한 친수성 용액 처리의 경우에 있어서는 수산화기가 3474 $cm^{-1}$ 주위의 넓은 영역에서 관찰되었다. 그러나, diluted HF 용액의 경우에 있어서는 수산화기가 관찰되지 않았다. 접합된 실리콘웨이퍼를 tetramethylammonium hydroxide 식각 용액을 사용하여 식각 공정을 수행하였다. 식각 공정은 자동 식각 중지가 수행되었으며, 식각된 표면은 평탄하고 균일하였다. 그러므로, 이러한 SDB 기술은 우수한 특성을 가진 압력, 유속, 가속도 센서 등과 같은 센서의 제작 및 센서 응용 분야에 이용될 수 있을 것이다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.182-185
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• 2005

Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

• 한국분말재료학회지
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• 제23권5호
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• pp.353-357
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• 2016

In this study, $TiO_2$ powders are synthesized from ammonium hexafluoride titanate (AHFT, $(NH_4)_2TiF_6$) as a precursor by heat treatment. First, we evaluate the physical properties of AHFT using X-ray diffraction (XRD), particle size analysis (PSA), thermogravimetric analysis (TGA), and field-emission scanning electron microscopy (FE-SEM). Then, to prepare the $TiO_2$ powders, is heat-treated at $300-1300^{\circ}C$ for 1 h. The ratio of anatase to rutile phase in $TiO_2$ is estimated by XRD. The anatase phase forms at $500^{\circ}C$ and phase transformation to the rutile phase occurs at $1200^{\circ}C$. Increase in the particle size is observed upon increasing the reaction temperature, and the phase ratio of the rutile phase is determined from a comparison with the calculated XRD data. Thus, we show that anatase and rutile $TiO_2$ powders could be synthesized using AHFT as a raw material, and the obtained data are utilized for developing a new process for producing high-quality $TiO_2$ powder.