• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1102-1107
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• 1999

FeAl matrix composite was fabricated successfully by hot-pressing. The mechanical properties of FeAl alloys have been widely studies, but their behaviors of surface hardening effect by plasma nitriding has not yet been studied. This study was to analysis the relationship between microstructure of the sintered composite by hot-pressing and surface hardening at plasma nitriding treatment. Surface hardening of FeAl base alloys was improved by plasma nitriding with increasing plasma treatment time. Excellent surface hardness in the FeAl alloys could be obtained by plasma nitriding($\textrm{H}_{\textrm{v}}$ 100gf, diffusion layer: 1100~1450kg/$\textrm{mm}^2$, matrix : 330~360kg/$\textrm{mm}^2$). Diffusion layer size increased with increasing plasma nitriding times and decreased with increasing Sic, content.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.458-458
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• 2013

We investigated a study on the thermal degradation of boron doped zinc-oxide (BZO) layer which used as a transparent conducting layer on the Cu (In1-xGax) Se2 (CIGS) based thin film solar cells. Devices were annealed under the temperature of $100^{\circ}C$ or 100 hours and then Hall measurement was carried out to characterize the parameters of mobility (${\mu}Hall$), resistivity (${\rho}$), conductivity (${\sigma}$) and sheet resistance (Rsh). The initial values of ${\mu}Hall$, ${\rho}$, ${\sigma}$ and Rsh were $29.3cm^2$/$V{\cdot}s$, $2.1{\times}10^{-3}{\Omega}{\cdot}cm$, $476.4{\Omega}^{-1}{\cdot}cm^{-1}$ and $19.1{\Omega}$/${\Box}$ respectively. After the annealing process, the values were $4.5cm^2$/$V{\cdot}s$, $12.8{\times}10^{-3}{\Omega}{\cdot}cm$, $77.9{\Omega}^{-1}{\cdot}cm^{-1}$ and $116.6{\Omega}$/${\Box}$ respectively. We observed that ${\mu}Hall$ and ${\sigma}$ were decreased, and ${\rho}$ and Rsh were increased. In this study, BZO layer plays an important role of conducting path for electrons generated by incident light onthe CIGS absorption layer. Therefore, the degradation of BZO layer characterized by the parameters of ${\mu}Hall$, ${\rho}$, ${\sigma}$ and Rsh, affect to the cell efficiency.

• Preventive Nutrition and Food Science
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• v.8 no.4
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• pp.306-314
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• 2003

Volatile flavor components, produced during the young (P-1), immature (P-2), mature (P-3) and old (P-4) growth stages, of shiitake mushrooms (Lentinus edodes), were extracted by simultaneous steam distillation and extraction (SDE), using a mixture of n-pentane and diethyl ether (1:1, v/v) as the extraction solvent. Analyses of the concentrates, by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS), led to the identification of 129, 129, 111 and 120 components in the P-1, 2, 3 and 4 stages, respectively. The major volatile compounds were l-octen-3-o1, 3-octanol, 3-octanone and 4-octen-3-one. Ethanol and ethyl acetate were also detected in large amounts. The characteristic volatile compounds found in shiitake mushrooms, such as dimethyl disulfide, dimethyl trisulfide and 1, 2, 4-thiolane, were at low concentrations in all samples. The amount of l-octen-3-o1 decreased as growth progressed, but concentrations of 3-octanone increased. The amount of 4-octen-3-ol decreased from P-1 to P-3, but was at a high concentrations in P-4. The concentration of 3-octanol gradually increased and reached its highest concentration in P-3, but decreased in P-4. The C8-compounds comprised 70.91, 64.09, 64.29 and 60.01 % in the P-1, 2, 3 and 4 stages, respectively, so decreased gradually with growth. The S-compounds were found in the highest concentrations in P-3.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.963-972
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• 2002

An 8192-point pipelined FFT/IFFT processor core is designed, which can be used in multi-carrier modulation systems such as DUf-based VDSL modem and OFDM-based DVB system. In order to improve the signal-to-quantization-noise ratio (SQNR) of FFT/IFFT results, two-step convergent block floating-point (TS_CBFP) scaling is employed. Since the proposed TS_CBFP scaling does not require additional buffer memory, it reduces memory as much as about 80% when compared with conventional CBFP methods, resulting in area-and power-efficient implementation. The SQNR of about 60-㏈ is achieved with 10-bit input, 14-bit internal data and twiddle factors, and 16-bit output. The core synthesized using 0.25-$\mu\textrm{m}$ CMOS library has about 76,300 gates, 390K bits RAM, and twiddle factor ROM of 39K bits. Simulation results show that it can safely operate up to 50-㎒ clock frequency at 2.5-V supply, resulting that a 8192-point FFT/IFFT can be computed every 164-${\mu}\textrm{s}$. It was verified by Xilinx FPGA implementation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.226-230
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• 2018

Pure $BiFeO_3$ (BFO) and codoped $Bi_{0.9}A_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (A=Eu, Dy) thin films were prepared on Pt(111)/Ti/$SiO_2$/Si(100) substrates by chemical solution deposition. The remnant polarizations (2Pr) of the $Bi_{0.9}Eu_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (BEFZO) and $Bi_{0.9}Dy_{0.1}Fe_{0.975}Zn_{0.025}O_{3-{\delta}}$ (BDFZO) thin films were about 36 and $26{\mu}C/cm^2$ at the maximum electric fields of 900 and 917 kV/cm, respectively, at 1 kHz. The codoped BEFZO and BDFZO thin films showed improved electrical properties, and leakage current densities of 3.68 and $1.21{\times}10^{-6}A/cm^2$, respectively, which were three orders of magnitude lower than that of the pure BFO film, at 100 kV/cm.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.236-236
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• 2013

비냉각 적외선 검출기는 산업용 군사용으로 최근 각광을 받고 있다. 이는 주야간 빛이 없는 곳에서도 사물의 열을 감지할 수 있어 인체감지 및 보안감시, 에너지 절감 등에 응용될 수 있는 핵심부품이다. 비냉각 적외선 검출기로는 재료의 저항의 변화를 감지하는 마이크로볼로미터형이 가장 많이 사용된다. 감지재료로는 비정질 실리콘(a-Si)과 산화바나듐(VOx)이 가장 많이 사용된다. VOx 박막은 일반적으로 RF sputtering 방법으로 증착이 되며, 저항이 낮고, 저항의 온도변화 계수(TCR)가 크며 신호 대 잡음 특성이 우수한 반면 산소(oxygen) phase가 다양하여 갓 증착된 상태의 박막은 재현성이 떨어지는 단점이 있다. 본 연구에서는 기존의 V 타겟을 사용한 VOx 박막을 증착하는 방법을 개선하여 ZnO 나노박막을 중간에 삽입하여 저항 특성을 조절할 뿐만 아니라 열처리에 의해 TCR 값을 향상시키고, VO2 phase 가 주로 나타나는 박막 증착 및 공정 방법을 소개한다. RF sputtering 장비를 이용하여 산소와 아르곤 가스의 혼합비를 4.5로 하였으며, VOx 증착 시 플라즈마 Power는 150 W 로 하여 상온에서 증착하였다. 갓 증착된 VOx 다층박막의 XRD 스펙트럼은 V2O5 피크가 주된 상을 이루고 있었으며, 산소열처리에 의해 VO2 상이 주로 나타남을 알 수 있었다. TCR 값은 갓 증착된 샘플에서 -0.13%/K의 값을 얻었으며, $300^{\circ}C$에서 50분간 열처리 후 -3.37%/K 으로 급격히 향상됨을 알 수 있었다. 저항은 열처리 후 약 100 kohm으로 낮아져 검출소자를 위한 조건에 적합한 특성을 얻을 수 있었다. 또한 산소열처리의 온도 및 시간에 따라 TCR 및 표면 거칠기 특성을 조사하였으며, 최적의 열처리 조건을 얻고자 하였다.

• Journal of Life Science
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• v.13 no.4
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• pp.463-472
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• 2003

Interactions between factor Va (HFVa) and membrane phosphatidylserine (PS) regulate the activity of the prothrombinase complex. I have previously shown that two solvent exposed hydrophobic residues located in the C2-domain, Trp2063 and Trp2064, are required for binding to immobilized PS and for expression of procoagulant activity on membranes containing 5% PS. In order to fully define the functional importance of these two residues I have expressed and isolated recombinant factor Va (rHFVa) W2063A/W2064A double mutant. In contrast to the native protein the two glycoforms resulting from alternative glycosylation of Asn2181 eluted as a single peak with rHFVa1 W2063A/W2064A eluting on the leading edge and rHFVa2 W2063A/W2064A eluting on the trailing edge. The double mutant rHFVa2 W2063A/W2064A expressed little or no procoagulant activity on membranes containing 1-10% mol % PS. In contrast, the procoagulant activity of this mutant was slightly greater than the native protein on membranes containing>18 mol % PS. The binding of rHFVa2 W2063A/W2064A to immobilized phospholipid vesicles was markedly reduced compared to the native protein in a surface plasmon resonance binding assay. I conclude that Trp2063 and Trp2064 are required for high affinity binding of factor Va to PS membranes and that this interaction is necessary for assembly of the prothrombinase complex on membranes containing physiological concentrations of PS.

• Journal of Convergence for Information Technology
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• v.9 no.3
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• pp.75-81
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• 2019

In this work, we investigated a low temperature polycrystalline silicon (LTPS) thin film transistors fabrication process on polymer layers. Dehydrogenation and activation processes were performed by a furnace annealing at a temperature of $430^{\circ}C$ for 2 hr. The crystallization of amorphous silicon films was formed by excimer laser annealing (ELA) method. The p-type device performance, fabricated by polycrystalline silicon (poly-Si) films, shows a very good performance with field effect mobility of $77cm^2/V{\cdot}s$ and on/off ratio current ratio > $10^7$. We believe that the poly-Si formed by a LTPS process may be well suited for fabrication of poly-Si TFTs for bendable panel displays such as AMOLED that require circuit integration.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.625-638
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• 2022

This study aimed to carefully investigate the effect of hydrolysis using Flavourzyme on meat quality, antioxidative status, and taste-related compounds in breast of Samgyetang that was supplemented with black garlic (BG). Four different treatment groups were compared: (1) conventional Samgyetang (control), (2) Samgyetang hydrolyzed with Flavourzyme (1%, v/w) (FS), (3) Samgyetang made with the BG extract without hydrolysis (NBG), and (4) BG samgyetang pre-treated with Flavourzyme (1%, v/w) in a water bath at 55℃ for 2.5 h and hydrolyzed before being processed (HBG). All the treatment groups were cooked by retorting at conditions 121℃ and 1.5 kg/cm² for 1 h. Improved umami profiles through the increase of umami-related nucleotides (5c-GMP, 5'-IMP) and free amino acids-aspartic acid and glumtamic acid, in Samgyetang breast was recorded following hydrolysis. The HBG group tended to impart stronger scavenging activity toward free radicals compared with the other two groups, while not differing with NBG group regarding suppressing malondialdehyde. Textural properties were improved through hydrolysis, wherein the shear force value decreased from 2.29 kgf in the control to 1.19 and 1.25 kgf in the FS and HBG group. Moisture percentages were highly retained, with the redness score increasing and the lightness color decreasing following hydrolysis. In conclusion, the results of this study can be a preliminary information of the effect of hydrolysis pre-treatment for BG samgyetang. Further experiments are required to compare various enzymes along with its organoleptic acceptances.

• Analytical Science and Technology
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• v.36 no.1
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• pp.32-43
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• 2023

This study reports for the first time about a stability indicating RP-HPLC method for qualitative and quantitative determination of acalabrutinib in bulk and dosage form and in presence its impurities 1, 2 and 3. The chromatographic separation was carried on Zorbax XDB-C18 (250×4.6 mm; 5 µ id) as stationary phase, Phosphate buffer pH 6.4 and methanol 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL/min, UV detection was carried at wavelength of 238 nm and the analysis was completed with a run time of 15 min. In these conditions the retention time of acalabrutinib and its impurities 1, 2 and 3 was observed to be 3.50, 4.83, 8.40 and 9.93 min respectively. The method was validated for system suitability, range of analysis, precision, specificity, stability and robustness. Spiked recovery at 50 %, 100 % and 150 % was carried for both standard and impurities and the acceptable % recovery of 98-102 was observed for acalabrutinib and both impurities studied and the % RSD in each spiked level was found to be less than 2. Stability tests were done through exposure of the analyte solution to five different stress conditions i.e expose to 1N hydrochloric acid, 1 N sodium hydroxide, 3 % peroxide, 80 ℃ temperature and UV radiation at 254 nm. In all the degradation condition, standard drug acalabrutinib was detected along with both the impurities studied and the degradation products were successfully separated. In the formulation analysis there is no other chromatographic detection of other impurities and formulation excipients. Hence the developed method was found to be suitable for the quantification of acalabrutinib and can separate and analyse impurities 1 and 2.