• Bulletin of the Korean Chemical Society
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• v.6 no.1
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• pp.29-32
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• 1985

Normal modes of crystalline orthorhombic sulfur belonging to the space group $D_{2h}$-Fddd, have been evaluated by taking the lowest temperature phase in the solid. Normal modes are obtained by the valence force field with modified force constants and a quantitative description of the mode is adjusted by the potential energy distribution. Since the full crystal system of orthorhombic sulfur is so large, we intended to calculate the normal modes simply by constructing the imaginary box made by the infinite mass boundary. And the Raman experiment is done by using the more powerful Ar-Kr gas laser with lowering the temperature to ${\sim}10^{\circ}K$.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.144-152
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• 1995

This study was carried out in order to utilize ginseng marc (GM), a byproduct produced during the preparation of ginseng extract. For the utilization of GM as coffee-replacing beverage, GM was roasted at 140-23$0^{\circ}C$, for 10-30 min to generate coffee-like flavor and taste. The physicochemical changes in GM induced by roasting process was measured. Weight and moisture contents of GM abruptly decreased while roasting at various temperature and period of time, and the amount of water-extracted solid substances decorated beyond 23$0^{\circ}C$. Among the proximate components, total and free sugar decreased remarkably, while crude fat content increased. Crude protein content did not change by the roasting process. pH derides to pH 4.9 after 30 min at 20$0^{\circ}C$, but increased at higher temperatures. Hunter color L value of the GM powder decreased, whereas a and b values, increased up to 10 times as compared to that of the control. The brown color(O, D 490 nm) in 50% ethanol extract of the roasted GM was 46 times higher than that of the control.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.1-5
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• 2021

Ultraviolet (UVA)-emissive BaSiO₃:Ce³⁺ phosphor was astonishingly reproducible by vacuum-sintering at a high temperature through a simple solid-state reaction method. It was conveniently formed in BaSiO₃ phases. The compound showed the UVA emission and the UV-VUV excitation due to 5d-4f transitions from Ce³⁺ ions: emission peak at 380 nm with a 56 nm width. Its temperature dependence and vacuum UV excitability were examined for practical application as an excimer discharge lamp, which showed the high thermal stability (80% at 100℃) and the strong VUV excitations at 145 nm and 172 nm.

• Annual Conference of KIPS
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• 2010.04a
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• pp.531-533
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• 2010

솔리드 텍스처 합성에서 최종 결과의 품질과 마찬가지로 텍스처 합성에 필요한 계산을 단축하는 것은 중요하다. 최근 연구에서는 데이터 차원 감소나 k-coherence search 같은 매칭 가속화 방법을 사용해서 솔리드 텍스처 합성 시간을 단축하였다. 본 논문에서는 빠르게 2D 이미지로부터 솔리드 텍스처 합성을 할 수 있는 새로운 방법을 제시한다. 제안하는 방법의 기본 아이디어는 주어진 이미지를 다수 영역으로 분할하여 형상 매칭(feature matching) 과정에서 사용되는 후보 수를 줄이는 것으로, 사물을 이루는 복셀과 관련한 픽셀이 포함된 분할 영역내의 후보들과 비교함으로써, 보다 빠르게 최적의 결과값을 제공한다. 실험적으로 본 방법은 k-coherence search 알고리즘에서 k 값을 1 로 사용했을 때보다 빠르거나 비슷한 시간을 갖는다.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.86-96
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• 1995

Alum recovery has recently gained more attention because many water utilities need to improve their sludge handling and disposal practices. As part of an overall sludge management program recovery can reduce the amount of solids and allow for reuse of the recovered Alum as a coagulant. This study was examined the effectiveness of Alum recovery from the Sludge at the D water treatment plant in Kwangju city. The results were summarized as follows 1. Alum recovery was obtained sufficiently acidification(An optimum condition was pH2-3) With $H_{2}SO_{4}$ to settled sludge. In this case recovered liquid Alum from sludge of 2.1% solids concentration at pH 2.1 was contains Aluminum $1,602mg/{\ell}$(as $Al_{2}O_{3}$ 0.3% ) and other metal of low level. 2. It was an optimum condition to all reuse of recovered Alum as a coagulant that rate of Commercial Alum:Recovered Alum=$14{\mu}{\ell}/{\ell}{\;}:{\;}200{\mu}{\ell}/{\ell}$ In a result of Jar Tests. 3. It was a result of Alum recovery from sludge, the reduction effect of amount of solids was about 57.4%. 4. If all recovered Alum were reused the reduction effect of solid wastes disposal cost and chemical drug's cost was about 22%.

• Journal of the Korean Magnetic Resonance Society
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• v.14 no.2
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• pp.88-104
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• 2010

Human melanocortin-4 receptor (hMC4R) has a critical role in part of energy homeostasis, and their heterozygous mutations related in genetic cause of severe human obesity. In order to study the structure and function of these membrane proteins, it is important to prepare the samples. However, the preparation of transmembrane peptide is seriously difficult and time-consuming. Overexpression and purification of membrane proteins was reported to be difficult due to their innate insoluble and toxic properties. Among the many difficulties, the most important is the difficulty in obtaining sufficient quantities of purified protein. Recently, we succeed to produce large amounts of the second transmembrane domain from the wild-type hMC4R (wt-TM2) and D90N mutant hMC4R (m-TM2) and proposed the structural difference of them in membrane-like environments. In this paper, we demonstrate the optimization procedures to express and purify wt-TM2 or m-TM2 peptides, and solution NMR studies in different detergents to get high-resolution spectra were also described.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.27-34
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• 2000

The chloroform and methanol (2;1, v/v) extract from an edible plant, Actinidia arguta Planchon, appeared to possess antitumor activity against human leukemias Jurkat T and U937 cells through inducing apoptosis. The substance in the solvent extract was purified by silica gel column chromatography, preparative TLC, and Sephadex LH-20 column chromatography. Characteristics of the substance analyzed by UV scanning analysis, $^1H$ and $^{13}C$ NMR spectra suggested that the substance belongs to the chlorophyll derivatives-like group. The $IC_{50}$ value of the chlorophyll derivative (Cp-D) determined by MTT assay was $15\mu\textrm{g}/ml$ for Jurkat, $10\mu\textrm{g}/ml$ for U937, and $11.4\mu\textrm{g}/ml$ for HL-60m and was more toxic to these leukemias than to solid tumors or normal fibroblast. In order to elucidate cellular mechanisms underlying the cytotoxicity, the effect of the Cp-D on Jurkat T cells was investigated. When cells were treated with the Cp-D at a concentration of $15\mu\textrm{g}/ml$, [3H]thymidine incorporation declined rapidly and wa undetectable in 1h. However, no significant changes were made in the cell cycle distribution of the cells by 24h. The sub-Gl peak representing apoptotic cells began to be detectable in 36h, at which time apoptotic DNA fragmentation was also detected on agarose gel electrophoresis, demonstrating that the cytotoxic effect of the Cp-D is attributable to the induced apoptosis. Under the same conditions, although the protein level of cyclin-dependent kinases such as cdc4, csk6, cdk2, and cdc2 was not significantly changed until 24h, the kinase activity of all c안 rapidly declined and reached a minimum level within 1-6h and then recovered to the initial level by 12h and sustained until 24h. These results suggest that inactivation of cdks at an inappropriate time during the cell cycle progression in jurkat T cells following a treatment with the Cp-D leads to induction of apoptotic cell death.

• Journal of the Korean Society for Nondestructive Testing
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• v.14 no.4
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• pp.237-243
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• 1995

We have studied methods of detecting attenuation of solid materials such as silicon wafer and piezoelectric $LiTaO_3$ by means of optical probing techniques. We have performed measurements of surface acoustic waves(SAW) generated from 90 degree wedge type transducer and also from inter-digital transducers(IDT). SAW of 20.0 MHz was generated on a silicon wafer from the 90 degree wedge type transducer and those of 20.8 and 14.5 MHz are generated on a $LiTaO_3$ from the IDT. Then any surface-corrugation resulted from the above SAW was investigated by He-Ne laser beams. We projected laser beams, which were modulated by an optical chopper, on the SAW of the same frequency and then measured the scattered beam by the lock-in amplifier. We modulated and synchronized both SAW and the incident laser beam as well as the phase sensitive detector(PSD) to the same frequency in order to simplify our measurement system. We obtained the attenuation coefficients of SAW to be $0.62{\sim}0.75dB/mm$(from IDT1, 20.8 MHz), and $0.60{\sim}0.72dB/mm$(from IDT2, 14.5 MHz), $0.83{\sim}1.28dB/mm$(from the wedge type), respectively.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.9-15
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• 2021

Miniaturization of semiconductor devices has recently faced a physical limitation. To overcome this, 3D packaging in which semiconductor devices are vertically stacked has been actively developed. 3D packaging requires three unit processes of TSV, wafer grinding, and bonding, and among these, copper bonding is becoming very important for high performance and fine-pitch in 3D packaging. In this study, the effects of Ti nanolayer on the antioxidation of copper surface and low-temperature Cu bonding was investigated. The diffusion rate of Ti into Cu is faster than Cu into Ti in the temperature ranging from room temperature to 200℃, which shows that the titanium nanolayer can be effective for low-temperature copper bonding. The 12nm-thick titanium layer was uniformly deposited on the copper surface, and the surface roughness (R_q) was lowered from 4.1 nm to 3.2 nm. Cu bonding using Ti nanolayer was carried out at 200℃ for 1 hour, and then annealing at the same temperature and time. The average shear strength measured after bonding was 13.2 MPa.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.638-643
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• 1996

The efficiency of dewatering of soybean milk residue was improved by hydraulic pressing after pH adjustment to 4.5 with organic acids such as acetic and lactic acids. Water content of raw soybean milk residue was reduced from 80% to 72% by pressing after pH adjustment, while only to 78% by the conventional hydraulic press. The water content of the residue after pH adjustment was further reduced to 63% by hydraulic pressing with ohmic heating. The pH adjustment facilitated separation of cake from the filter cloth and reduced the solid content of the expressed liquid from 10 to 3%.