• 한국재료학회지
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• 제18권2호
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• pp.98-102
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• 2008

The ferroelectric properties of UV irradiated and non-irradiated PZT films prepared via photochemical metal-organic deposition using photosensitive precursors were characterized. Fourier transform infrared spectroscopy showed that complete removal of organic groups was possible through UV exposure of the spin-coated PZT precursor films at room temperature. The measured remnant polarization values of UV-irradiated and non-irradiated PZT films after annealing at $650^{\circ}C$ were 29 and $23\;{\mu}C/cm^2$, respectively. The UV irradiation was found to be effective for the enhancement of the <111> growth orientation and ferroelectric property of PZT film and in the direct patterning in the fabrication of micro-patterned systems without dry etching.

• 한국분말재료학회지
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• 제26권2호
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• pp.119-125
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• 2019

Piezoelectric energy harvesting technology is attracting attention, as it can be used to convert more accessible mechanical energy resources to periodic electricity. Recent developments in the field of piezoelectric energy harvesters (PEHs) are associated with nanocomposites made from inorganic piezoelectric nanomaterials and organic elastomers. Here, we used the $BaTiO_3$ nanoparticles and piezoelectric poly(vinylidene fluoride) (PVDF) polymeric matrix to fabricate the nanocomposites-based PEH to improve the output performance of PEHs. The piezoelectric nanocomposite is produced by dispersing the inorganic piezo-ceramic nanoparticles inside an organic piezo-polymer and subsequently spin-coat it onto a metal plate. The fabricated organic-inorganic piezoelectric nanocomposite-based PEH harvested the output voltage of ~1.5 V and current signals of ~90 nA under repeated mechanical pushings: these values are compared to those of energy devices made from non-piezoelectric polydimethylsiloxane (PDMS) elastomers and supported by a multiphysics simulation software.

• 한국전기전자재료학회논문지
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• 제35권4호
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• pp.366-371
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• 2022

Recently many efforts have been made to develop a novel class of non-fullerene electron acceptor materials for high-performance organic solar cells. In this work, anthraquinone derivatives, TMAQ and THAQ, were prepared and their availability as electron acceptor materials for organic solar cells were investigated in terms of optical, thermal, electrochemical properties, and solar cell devices. Compared to TMAQ, a significant bathochromic shift of absorption band was observed for THAQ owing to intramolecular hydrogen-bond-assisted CT interactions. Thanks to the fused aromatic ring structure and benzoquinone unit, both TMAQ and THAQ exhibited a high thermal stability and an efficient electron reduction process. In particular, the intramolecular O-H---O=C hydrogen bond of THAQ plays an important role in improving the thermal stability and electron reduction properties. In the P3HT:acceptor solar cell system, THAQ-based devices had more than ca. 6 times higher power conversion efficiency than TMAQ -based devices. These results serve as a guide for developing high-efficient anthraquinone-based electron acceptor materials.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.370.1-370.1
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• 2016

Volatile organic compounds (VOCs) are considered hazardous air pollutants and these are emitted from building materials and household products. VOCs can cause global warming as well as human sickness, and even cancer. Photocatalysis provides a way of converting VOCs into harmless materials. Various researches have shown that $TiO_2$ is the most efficient photocatalysts due to its excellent activity. In this study, metal/non-metal doped $TiO_2$ particles are synthesized for the enhancement of the photocatalytic properties of pure $TiO_2$. By metal/non-metal doping, band gap energies of prepared samples were analyzed by UV/Visible spectrophotometer. The physical and chemical properties of synthesized powder were characterized by field emission scanning electron microscope, by BET for measuring their specific surface area, and by XRD for phase identification and particle size determination. Degradation ability for p-xylene was evaluated through monitoring the concentration in a closed chamber. Relation between their properties and decomposition abilities for VOC were evaluated based on the experimental results.

• 한국세라믹학회지
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• 제41권5호
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• pp.349-352
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• 2004

Organic-inorganic hybrid sol based on ZrO$_2$-SiO$_2$ system was prepared by sol-gel process. Firstly, ZrO$_2$ non-aqueous precursor sol was synthesized and then organosilane compounds which include epoxy silane (GPTS; 3-g1ycidoxypropyl tri-methoxysilane) and acryl silane (ACS; (3-(tri-methoxysilyl)propylmethacrylate)) were added to ZrO$_2$precursor sol for hybridization. Finally, com-mercial silica sol was added to improve the mechanical properties. Synthesized organic-inorganic Zr-hybrid sol was coated on polycarbonate substrate for enhancing it’s mechanical properties, especially hardness. Vicker’s hardness of polycarbonate sub strate was increased from 13.6 to 17.8 MPa and its pencil hardness was increased from 2 to 7 H, respectively, after coating and drying at 10$0^{\circ}C$ for 30 min.

• Journal of Information Display
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• 제10권2호
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• pp.80-86
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• 2009

The variation of the electrical characteristics of thin-film transistors (TFTs) causes a non-uniform image quality problem, and the differential aging of organic light-emitting diode (OLED) devices causes an image-sticking problem. A video data correction method is proposed herein as an effective solution to the non-uniform electro-optical characteristics of the pixels in activematrix organic light-emitting diode (AMOLED) displays. The results of the simulation that was conducted show that the proposed method successfully senses the electrical characteristics of TFTs and the degradation of OLEDs and effectively compensates for them.

• Applied Microscopy
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• 제51권
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• pp.9.1-9.10
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• 2021

Brain disorders seriously affect life quality. Therefore, non-invasive neuroimaging has received attention to monitoring and early diagnosing neural disorders to prevent their progress to a severe level. This short review briefly describes the current MRI and PET/CT techniques developed for non-invasive neuroimaging and the future direction of optical imaging techniques to achieve higher resolution and specificity using the second near-infrared (NIR-II) region of wavelength with organic molecules.

• 한국식품영양과학회지
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• 제45권2호
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• pp.298-305
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• 2016

발효과정(양파 알코올 발효 및 양파 초산 발효) 중의 정미성분을 분석하였다. 유기산의 분석 결과 양파 착즙액(유기산 함량 1,180.8 mg/100 g)에서 malic acid(50.1%)와 citric acid(26.9%)가 대부분의 함량을 차지하였다. 양파 알코올 발효액(유기산 함량 2,008.8 mg/100 g)은 malic acid(28.1%), acetic acid(20.8%), lactic acid(20.1%), citric acid(13.3%) 및 succinic acid(12.0%) 순으로 높은 함량을 차지하였다. 양파 초산 발효액의 총유기산 함량은 4,612.0 mg/100 g으로 양파 착즙액이나 알코올 발효액에 비해 각각 약 3.9배와 2.3배 증가하였으나 acetic acid 이외 유기산의 함량은 감소하였다. 비단백태 질소화합물은 양파 착즙액(총비단백태 질소 함량 $9,803.1{\mu}g/100g$)에 비하여 알코올 발효 후 4.23배($41,526.8{\mu}g/100g$)로 증가하였고, 특히 urea(81.43%)가 두드러지는 증가를 보였다. 양파 초산 발효액은 $2,658.9g/100g$으로 초산균의 생육과 관련하여 소비가 이루어진 것으로 사료된다. 양파 착즙액에 검출된 유리당(포도당, 과당, 자당)은 발효과정 중 과당을 제외하고는 검출되지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.907-915
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• 2010

Three hundred and seventy-three steers (approximately 7 mo of age and $247{\pm}19.4\;kg$) were utilized to determine the effects of trace mineral (TM) source and growth implants on trace mineral status. Steers were blocked by ranch, post-weaning treatment within ranch, stratified by initial body weight, and randomly assigned to one of 36 pens (9-12 head/pen). Treatment consisted of: I) control (no supplemental Cu, Zn, Mn, and Co), ii) inorganic trace minerals, and iii) organic trace minerals. Six pens of steers per treatment received a growth implant at the beginning of the experiment and were re-implanted during the finishing phase. The remaining steers received no growth implants. Steers were fed a corn silage-based growing diet for 56 d then were gradually switched to a high concentrate finishing diet. Treatments during the finishing phase consisted of: i) control (no supplemental Zn); ii) inorganic Zn (30 mg of Zn/kg DM from $ZnSO_4$); and iii) organic Zn (iso-amounts of organic Zn). By the end of the growing and finishing phases, implanted steers had greater (p<0.01) plasma Cu concentrations than non-implanted steers. During the growing phase, liver Cu concentrations (p<0.01) and plasma Zn concentrations (p<0.02) were greater in steers supplemented with TM compared to control steers. Steers supplemented with inorganic minerals had greater liver Cu concentrations than steers supplemented with organic minerals at the beginning (p<0.01) and end (p = 0.02) of the growing phase. During both the growing (p = 0.02) and finishing phases (p = 0.05), nonimplanted control steers had greater plasma Cu concentrations than non-implanted steers supplemented with TM, whereas, implanted control steers had similar plasma Cu concentrations than implanted steers supplemented with TM. Non-implanted steers that received inorganic TM had lower plasma Cu concentrations (p = 0.03) during the growing phase and ceruloplasmin activity (p<0.04) during the finishing phase than non-implanted steers that received organic TM, whereas, implanted steers supplemented with either organic or inorganic TM had similar plasma Cu concentrations.

• 한국식품영양과학회지
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• 제22권1호
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• pp.53-57
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• 1993

국내 김치류 가운데 향토식품으로서 연구개발의 필요성이 있는 갓의 비휘발성 유기산, 무기질, 지방산조성 및 섬유소 등에 대한 성분분석 결과는 비휘발성 유기산은 잎줄기보다 잎에 많았으며, 특히 malic acid의 함량이 79.lmg%로서 가장 높았고, citric acid는 23.7mg%로서 잎의 함량이 잎줄기보다 4배 정도 더 많았다. 잎과 잎줄기의 무기질은 칼슘(143.7, 81.3mg%)과 마그네슘(22.7, 14.5 mg%)이 높게 나타났으며, 대체로 잎의 무기질함량은 잎줄기에 비하여 1~1.8배 정도 많았다. 특히 철 (6.9, 7.3mg%)은 다른 십자화과 채소에 비하여 상당히 많았다. 총지질을 구성하는 지방산 조성은 $\alpha$-linolenic acid, palmitic acid 그리고 linoleic acid가 대부분을 차지하며, 불포화지방산의 함량이 포화지방산에 비하여 3.7배 많으며, 잎과 잎줄기의 P/S비율이 각각 4.1과 2.9로서 잎이 1.4배 높았다. 식이성 섬유질 중 펙틴질에 있어서 잎과 잎줄기의 알코올불용성성분 (AIS)은 9.4및 6.7%로서 잎의 AIS함량이 1.4배 많았으며, 잎과 줄기에서 공통적으로 AIS는 열수수용성펙틴(HWSP), 인산염가용성펙틴(HXSP), 염산가용성펙틴(HSP)이 4.1 : 2.8 : 1의 비로 구성되며, HXSP와 HSP의 함량이 크게 차이를 보였다. 또한 총 식이성섬유질의 함량은 잎과 잎줄기에서 각각 1.2와 2.8%를 함유하며, ADF에 비하여 NDF함량이 많았으며, 리그닌이 가장 적었다. 셀루로스는 헤미셀루로스에 비하여 2.1배 많았으며, 대체로 잎줄기에는 잎에 비하여 각 식이성 섬유소의 함량이 약간씩 높았다.