• Journal of the Semiconductor & Display Technology
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• v.5 no.1 s.14
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• pp.39-43
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• 2006

The polyvinyl series organic films as gate insulators of thin film transistor(TFT) have been processed and characterized on the polyether sulphone (PES) substrates . The poly-4-vinyl phenol(PVP) and polyvinyl toluene (PVT) were used as solutes and propylene glycol monomethyl ether acetate(PGMEA) as a solvent in the formation of organic insulators. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compound. The electrical characteristics measured in the metal-insulator-metal (MIM) structures showed that insulating properties of PVP layers were generally superior to those of PVT layers. Among the layers of PVP series; copolymer PVP(10 wt%), 5wt% cross-linked PVP(10 wt%), copolymer PVP(20 wt%), 5 wt% cross-linked PVP(20 wt%) and 10 wt% cross-linked PVP(20 wt%), the 10 wt% cross-linked PVP(20 wt%) layer showed the lowest leakage current of 1.2 pA at ${\pm}10V$. The ms value of surface roughness and the capcitance per unit area are 2.41 and $1.76nF/cm^2$ in the case of 10 wt% cross-linked PVP(20 wt%) layer, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3305-3311
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• 2012

Background: The present study aimed to find the prognostic implications of two polymorphisms in TP53 (p.R72P, PIN3 Ins16bp) and one in CCR5 ($CCR5{\Delta}32$) in sporadic breast cancer patients. Methods: DNA samples of 80 breast cancer patients and 80 age and gender matched unrelated healthy control individuals from Punjab, North West India were analyzed. Results: For p.R72P, the genotype frequency was 13.8% (RR), 58.8% (RP), 27.5% (PP) in patients and 33.9% (RR), 40.0% (RP), 26.5% (PP) in controls. For PIN3 Ins16bp, the genotype frequencies were 53.75% (A1A1), 37.5% (A1A2), 8.75% (A2A2) in patients and 66.3% (A1A1), 31.3% (A1A2), 2.5% (A2A2) in controls. Only 4 (5%) breast cancer patients were heterozygous for $CCR5{\Delta}32$ deletion. Common RR-A1A1-WT/WT genotype was lower while RP-A1A2-WT/WT genotype was higher in patients as compared to controls. RP-A1A1-WT/WT genotype was significantly higher in patients as compared to control individuals (p = 0.008). Conclusion: Though a clear association of any particular genotype with sporadic breast cancer or stage was not apparent, the results of present study were suggestive that sporadic breast cancer patients with RR-A1A1-WT/WT genotype might have a better response to chemotherapy, thus improving their chances of survival.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1099-1109
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• 1998

To investigate the effect of V and Sb on the corrosion behavior of Zr- based alloys, corrosion tests were performed on 6 kinds of Zr alloys in an autoclave at $360^{\circ}C$ for 100 days. The transition of the corrosion rate occurred in the sample containing 0.1wt.%V after 10 days but did not occur in the samples containing 0.2wt.%V and 0.4wt.%V. The corrosion resistance of V containing alloys increased with increasing V contents from 0.1 to 0.4wt.% and the alloys containing 0.4wt.%V showed the best corrosion resistance. In the ternary alloys containing 0.1wt.%Sb and 0.4wt.%Sb, the corrosion rate increased significantly from the short exposure time. It was observed that the optimal Sb content for corrosion resistance was 0.2wt.%. The size and volume fraction of precipitates increased with increasing V and Sb contents. The superior corrosion resistance was observed in the Zr alloy having precipitate size of 0.11-0.13$\mu\textrm{m}$. From the result of corrosion behavior and the obserbation of precipitates, the optimal size of the precipitate appear to control the electron conduction in the cathodic reaction and play an important role in maintaining a stable oxide microstructure.

• Journal of the Korean Ceramic Society
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• v.35 no.4
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• pp.330-330
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• 1998

Active belite cement clinkers were synthsized by using natural raw materials with borax and calcium phosphate ({{{{ {Ca }_{3 }( {PO}_{4}) }}2) In both case {{{{alpha ^、 {C }_{2 }S }} were formed but borax was more efficient. The cement syn-thesized with the addition of borax was hydrated with the addition of anhydrite(5 wt%) and slag(30wt%, 40wt% 50wt%) The addition of 50wt% slag with anhydrite was good for strength development in 7days and the compressive strength was developed to twice than no addition of slag at 28 days strength.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.137.1-137.1
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• 2011

올리빈 구조의 $LiFePO_4$ 정극 활물질은 $650^{\circ}C$에서 고상법으로 제조되었다. $LiFePO_4$의 전자전도도를 향상시키기 위하여 graphite nanofiber(GNF)를 각각 3wt%, 5wt%, 7wt%, 9wt% 첨가하여 $LiFePO_4$-C를 제조하였다. 제조된 분말의 입자 형태를 확인하기 위하여 X-ray diffraction(XRD)과 File Electronic Scaning Electromicroscopy(FE-SEM)를 측정하였다. XRD결과로부터 제조된 분말은 모두 순수한 결정 구조를 나타내었고 입자의 크기는 약 200nm였다. 5wt% GNF를 첨가한 $LiFePO_4$-C는 기타 첨가량에 비해 방전용량이 가장 높았다. 첫 사이클의 용량은 151.73mAh/g 나타났고 50 사이클 뒤에도 92% 이상을 유지하고 있었다. 첨가하지 않은 것에 비해 43% 증가하였다. $LiFePO_4$-C(3wt%), $LiFePO_4$-C(7wt%), $LiFePO_4$-C(9wt%)의 첫 사이클 방전용량은 각각 147.94mAh/g, 136.64mAh/g, 121.07mAh/g 나타났다. $LiFePO_4$-C(5wt%)에 비해 용량은 떨어쪘지만 순수한 $LiFePO_4$보다 많이 높았다. 임피던스 결과를 보면 기타 첨가량에 비해 $LiFePO_4$-C(5wt%)의 저항 제일 낮았다. 이는 충방전 결과와 일치하였다. graphite nanofiber의 첨가로 인하여 $LiFePO_4$ 정극 활물질의 전자전도도가 높아지고, 따라서 전기화학적 특성도 크게 향상되었다.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.675-687
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• 2006

The purpose of this study is to determine the geochemical characteristics of the stream sediments in the Cheongpung area. So that we can understand the natural background and predict the prospects of geochemical disaster, if any. We collected the stream sediments samples by wet sieving along the primary channels and slow dried the collected samples in the laboratory and ground them to pass a 200 mesh using an alumina mortar and pestle for chemical analysis. Miner-alogical characteristics, major, trace and rare earth elements were determined by XRD, XRF, ICP-AES and NAA analysis methods. For geochemical characteristics on the geological group of stream sediments, the studied area was grouped into granitic gneiss area, metatectic gneiss area, Dado tuff area, Yuchi conglomerate area, and Neungju flow area in the Cheongpung area. Contents of major elements for the stream sediments in the Cheongpung area were $SiO_2\;47.31{\sim}72.81\;wt.%,\;A1_2O_3 \;11.26{\sim}21.88\;wt.%,\;Fe_2O_3\;2.83{\sim}8.39\;wt.%,\;CaO\;0.34{\sim}7.54\;wt.%,\;MgO\; 0.55{\sim}3.59\;wt.%,\;K_2O\;1.71{\sim}4.31\;wt.%,\;Na_2O\;0.56{\sim}2.28\;wt.%,\;TiO_2\;0.46{\sim}1.24\;wt.%,\;MnO\;0.04{\sim}0.27\;wt.%,\;P_2O_5\;0.02{\sim}0.45\;wt.%$. The con-tents of trace and rare earth elements for the stream sediments were $Ba\;700ppm{\sim}8990ppm,\;Be\;1.0{\sim}3.50ppm,\;Cu\;6.20{\sim}60ppm,\;Nb\;12{\sim}28ppm,\;Ni\;4.4{\sim}61ppm,\;Pb\;13{\sim}34ppm,\;Sr\;65{\sim}787ppm,\;V\;4{\sim}98ppm,\;Zr\;32{\sim}164ppm,\;Li\;21{\sim}827ppm,\;Co\;3.68{\sim}65ppm,\;Cr\;16.7{\sim}409ppm,\;Cs\;2.72{\sim}37.1ppm,\;Hf\;4.99{\sim}49.2ppm,\;Rb\;71.9{\sim}649ppm,\;Sb\;0.16{\sim}5.03ppm,\;Sc\;4.97{\sim}52ppm,\;Zn\;26.3{\sim}375ppm,\;Ce\;60.6{\sim}373ppm,\;Eu\;0.82{\sim}6ppm,\;Yb\;0.71{\sim}10ppm$.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.167-181
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• 2020

Analysis of variance (ANOVA) and multiple comparison analysis were performed for shear strengths categorized by breccia content of 5 wt.% (Case-I), 10 wt.%, (Case-II) and 15 wt.% (Case-III) in fault cores. The relationship between breccia contetnt and shear strength was quantitatively classified by calculating the mean and standard deviation of shear strength for each population in each case and then the grouping the breccia contents that had a statistically similar effect on the dispersion of shear strength. As a result, shear strength was clearly classified into group 1 (breccia content of 0-15 wt.%) and group 2 and 3 (breccia coantent of 15-30 wt.% and 30 wt.% or more) in Case-III. Shear strength of the standard line at breccia content of 15 wt.% were determined to be 43.6 kPa, 77.6 kPa, and 118.6 kPa at each normal stress (54 kPa, 108 kPa, and 162 kPa), respectively. In addition, the distribution range of cohesions is 0-43.6 kPa at breccia content of 15 wt.% or less, and 0-70.0 kPa at 15 wt.% or more. Distribution range of friction angles is 0-45.7 ° at breccia content of 15 wt.% or less, and 16.7-57.5 ° at 15 wt.% or more.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.6
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• pp.257-261
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• 2004

The pottery stones from the Taebek area consist of abundant quartz with kaolinite. In this study, the characteristics of pottery stones were examined by XRD (X-ray diffractometer), XRF (X-ray fluorescence spectrometer), TG-DTA and SEM (Scanning Electron Microscope). The chemical compositions of the raw ore showed 71.75 wt%$SiO_2$, 22.10 wt%$Al_2O_3$, 1.86 wt%CaO, 2.97 wt%$K_2O$, 0.62 wt%$Fe_2O_3$. When pottery stone of 3 mm size was leached at $80^{\circ}C$ with 10 % oxalic acid, the content of $Fe_2O_3$ was reduced from 0.62 wt% to 0.24 wt% and the whiteness was enhanced. Grinding of pottery stone was conducted by a planetary ball mill using media of zirconia, the average particle size was 2～5 $\mu\textrm{m}$.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.987-992
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• 2001

A refractory grade low-cost silicon nitride powder was chemically analyzed, purified, and gas pressure sintered with the sintering additives. As-received powder contained a significant amount of free-Si, 0.72 wt% of Fe, 0.5 wt% of al and 0.31 wt% of Ca. Oxygen and carbon contents of the powder were 3.3 wt% and 0.4 wt%, respectively, and it consisted of 96% of $\beta$-phase and 4% of $\alpha$-phase. After lowering the Fe content and nitriding treatment, the powder was sintered with 6 wt% yttria and 2 wt% alumina for 1 h between 1823 K and 2123 K in order to examine the sintering behavior. Fully dense samples were obtained by sintering at 2123k for 2h. For comparison, a commercially available high-grade powder was also sintered at the same time. The low-cost powder showed much slower densification rate than the high-grade powder. Fully dense sample prepared from the low-cost powder contained a number of coarse grains with a low aspect ratio, and its hardness, fracture toughness, flexural strength and thermal shock resistance were not as good as those of the sample prepared with the high-grade powder.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.37-42
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• 2006

The preparation and processing of PVP-gate insulators on the device performance have been studied in the fabrication of organic thin film transistors (OTFTs). One of polyvinyl series, poly-4-vinyl phenol(PVP) was used as a solute and propyleneglycol monomethyl etheracetate(PGMEA) as a solvent in the formation of organic gate solutions. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compounds. From the measurements of electrical insulating characteristics of metal-insulator-metal (MIM) samples, PVP-based insulating layers showed lower leakage current according to the increase of concentration of PVP and poly (melamine-co-formaldehyde) to PGMEA in the formation of organic solutions. The PVP(20 wt%) copolymer with composition of 20 wt% PVP to PGMEA and cross-linked PVPs in which 5 wt% and 10 wt% poly (melamine-co-formaldehyde) hardeners had been additional]y mixed into PVP(20 wt%) copolymers were used as gate dielectrics in the fabrication of OTFTs, respectively. In our experiments, the maximum field effect mobility of $0.31cm^2/Vs$ could be obtained in the 5 wt% cross-linked PVP(20 wt%) device and the highest on/off current ratio of $1.92{\times}10^5$ in the 10 wt% cross-linked PVP(20 wt%) device.