• 한국재료학회지
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• 제7권5호
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• pp.374-380
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• 1997

열전재료 분말을 AI관에 진공봉입하고 형틀가입한 후 소결하는 새로운 방법으로 n형 B $i_{2}$T $e_{2.4}$S $e_{0.6}$를 제조하여 소결조건에 따른 소결성과 열전특성을 조사.분석하였다. AI은 소결시 열전재료와 반응하지 않아 보호 용기로 적합하였으며, 평균입도 195$\mu\textrm{m}$의 분말을 사용하여 성형압 280 MPa, 온도 400에서 50$0^{\circ}C$에서 소결할 경우 성능지수는 1.9x $10^{-3}$K였다.다.

• 정보학연구
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• 제5권1호
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• pp.39-50
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• 2002

본 연구는 최근 인터넷쇼핑몰 쇼핑의 폭발적 활용과 성장에 따라 국내 온라인 기업들에게 현재 및 미래의 중요한 시장으로 떠오르는 B2C 거래의 성공적으로 이끌기 위해 필요한 마케팅정보를 제공하고자 하는데 있다. 따라서 인터넷쇼핑몰 B2C 거래자의 I-VALS 군집분류를 탐색적으로 파악하였다. 이는 이러한 결과는 인터넷쇼핑몰에서 구매한 사이버소비자 집단의 구성원의 생활의식과 행동에 어떤 영향을 미치고 그 결과로 라이프스타일과 소비자행동에 어떠한 관계를 갖는가를 파악함으로써 시장세분화에 체계적으로 접근할 수 있는 프레임웍(framework)을 제공해 줄 것이다.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.40-50
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• 2022

The Périgord black truffle (Tuber melanosporum) is an edible fungus and among the most expensive foods worldwide. It is the basis of a multimillion-dollar bio-business. Truffle farming does not exist in Mexico, and no formal studies have been conducted on its culture. This report describes the mycorrhizal synthesis (i.e., artificial union of fungus with host) of T. melanosporum with oak species native to Mexico (Quercus polymorpha, Q. fusiformis, and Q. canbyi). The mycorrhizal association was successful in Q. polymorpha and Q. fusiformis, as confirmed morphologically and using T. melanosporum molecular primers (ITSML/ITS4LNG). The effect of the ectomycorrhizal fungus on host growth (stem diameter) was statistically significant. Illustrations of the study are presented.

• 천문학회보
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• 제40권1호
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• pp.69.1-69.1
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• 2015

Classical T Tauri star DG Tau is suggested as the driving source of parsec-scale jet which expands up to 650" (0.4 pc). To investigate the kinematics and physical properties of the jet, we have obtained the optical emission lines of $H{\alpha}$, [O I] ${\lambda}{\lambda}$6300, 6363, [N II] ${\lambda}{\lambda}$6548,6584, and [S II] ${\lambda}{\lambda}$6716, 6731 from HH 158 ad HH 702. The radial velocity of HH 158 is in the range of -50 to $-250km\;s^{-1}$. For HH 702, located at 650" from the source, it shows ~ $-80km\;s^{-1}$. In HH 158, the electron density ($n_e$) close to the star is ${\sim}10^4cm^{-3}$ and it decreases to ${\sim}10^2cm^{-3}$ at 14" away from the star. Electron temperature ($T_e$) is decreasing from >15,000 K to ~5,000 K with distance. Ionization fraction ($x_e$) is increasing from almost zero to > 0.4 along the distance. In HH 702, the values of $n_e$, $T_e$, and $x_e$ are similar to those estimated at 14" from source, where knot C of HH 158 is located. This may imply that the physical properties of the knot could persist through such a long distance in the space, and the gas could be re-excited by the shock during propagation of the jet. On the other hand, we cannot avoid the possibility that HH 702 is driven by another source rather than DG Tau because HH 158 and HH 702 show somewhat large difference in their inclination angles (${\Delta}i=21-35^{\circ}$).

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1421-1425
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• 2018

The dynamics of gas release at thermal oxidation of extraction systems on the basis of diamides of dicarbonic acids in fluorinated sulphones with 14 mol/L $HNO_3$ was investigated. The effect of preirradiation of the mixtures with accelerated electrons on the kinetics of their thermolysis was determined. The mixtures were heated in an autoclave at temperatures of 170 and $200^{\circ}C$ and irradiated using an electron accelerator to absorbed doses of 0.1, 0.5, and 1.0 MGy. It has been shown that no conditions for autocatalytic oxidation at thermolysis of extraction mixtures irradiated up to a dose of 1 MGy were developed.

• Current Research on Agriculture and Life Sciences
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• 제2권
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• pp.109-114
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• 1984

Eight Korean native black goats were used, $10m{\ell}$ of blood was collected from the Jugular vein into heparinized tubes a week interval. The heparinized blood was centrifuged for separation to blood plasma and corpuscles. The hematocrit, per centage of blood that is red blood cells, was reschuffuled of 10 %, 20 %, 30 %, 40 % and 50 % using blood plasma, 0.9 % NaCl solution and 5.4 % dextrose solution. The sedimentation rates of red blood cell obtained at $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$ are summarized as follows. 1) The sedimentation rates of red blood cell were more increased by lower PCV%, i.e. there was a reverse relationship between the sedimentation rates and PCV% at any condition of these experiments. 2) The RBC were sedimented the most quickly in the NaCl solution and slower in the plasma compare with the dextrose solution at the same PCV%. 3) There was no temperature effect on the sedimentation rates between the two groups of $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$(at PCV 20% and 10%), even though the temperature difference is $20^{\circ}C$.

• Tribology and Lubricants
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• 제35권2호
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• pp.106-113
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• 2019

We investigated the application of tetrahedral amorphous carbon (ta-C) coatings to fabricate a glass lens manufactured using a glass molding process (GMP). In this work, ta-C coatings with different thickness (50, 100, 150 and 200 nm) were deposited on a tungsten carbide (WC-Co) mold using the X-bend filter of a filtered cathode vacuum arc. The effects of thickness on mechanical and tribological properties of the coating were studied. These ta-C coatings were characterized by atomic force microscopy, scanning electron microscopy, nano-indentation measurements, Raman spectrometry, Rockwell-C tests, scratch tests and ball on disc tribometer tests. The nano-indentation measurements showed that hardness increased with an increase in coating thickness. In addition, the G-peak position in the Raman spectra analysis was right shifted from 1520 to $1586cm^{-1}$, indicating that the $sp^3$ content increased with increasing thickness of ta-C coatings. The scratch test showed that, compared to other coatings, the 100-nm-thick ta-C coating displayed excellent adhesion strength without delamination. The friction test was carried out in a nitrogen environment using a ball-on-disk tribometer. The 100-nm-thick ta-C coating showed a low friction coefficient of 0.078. When this coating was applied to a GMP, the life time, i.e., shot counts, dramatically increased up to 2,500 counts, in comparison with Ir-Re coating.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.117-118
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• 2000

The secondary electron emission coefficient ${\gamma}$ of MgO single crystals according to the gas mixture ratio of Xe to Ne have been investigated by ${\gamma}-focused$ ion beam system. It is found that the MgO single crystals of (111) crystallinity has the highest ${\gamma}$ from 0.09(0.03) up to 0.16(0.04), while from 0.07(0.02) to 0.15(0.03) for (200) and from 0.06(0.01) to 0.13(0.02) for (220) crystallinity for operating Ne (Xe) ions ranging from 50eV to 200eV throughout this experiment. And it is found that the ${\gamma}$ ranged from 0.03 up to 0.06 for Ne-Xe mixtures are much smaller than those of 0.09 up to 0.16 for pure Ne ions under accelerating voltage ranged from 50V to 200V.

• 한국식물병리학회지
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• 제14권3호
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• pp.191-202
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• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• 한국전기전자재료학회논문지
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• 제21권6호
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• pp.562-568
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• 2008

In this paper, the hole injection layer(HIL) materials have been synthesized and analyzed. Their HOMO levels are $4.93{\sim}5.22\;eV$, and their energy band gaps are $2.74{\sim}3.19\;eV$. Their glass transition temperatures($T_g$) are all above $114^{\circ}C$, which implies that they are highly thermal-stable. The green OLED devices with a structure of ITO(150 nm)/NEW_HIL(50 nm)/NPB(30 nm)/$Alq_3$(50 nm)/Al:Li(100 nm) were fabricated and tested, incorporating these newly synthesized HIL materials. According to the test results of OLED devices, the I-V-L performances of these devices increase in the following sequence: ELM307 > ELM200 > ELM321 > ELM327 > ELM325. In addition, the OLED device with ELM307 as a HIL has the highest brightness and efficiency at the same driving voltage. These experimental results have shown that ELM307 can be used as one of the most promising candidates for HIL materials.