• Natural Product Sciences
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• 제25권1호
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• pp.23-27
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• 2019

From the pericarps of Litsea japonica (Thunb.) Jussieu, eighteen butanolide derivatives (1 - 18) were evaluated for their cytotoxic activity against HeLa, HL-60, and MCF-7 cells. Compounds 1-9 with 2-alkylidene-3-hydroxy-4-methylbutanolides structure exhibited cytotoxic activities against cancer-cell lines. Among them, compound 8 (litsenolide $D_2$) exhibited the most potent cytotoxicity against the tested cell lines, including HeLa, HL-60, and MCF-7, with $IC_{50}$ values of $17.6{\pm}1.3$, $4.2{\pm}0.2$, and $12.8{\pm}0.0{\mu}M$, respectively. Compound 8 induced apoptosis in a dose-dependent manner. Annexin V/Propidium Iodide (PI) double staining confirmed that 8 effectively induced apoptosis in MCF-7 cells. To the best of our knowledge, we have reported cytotoxic activity of butanolides from L. japonica against these cancer-cell lines for the first time.

• 천문학회지
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• 제40권2호
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• pp.39-47
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• 2007

A high resolution spectrum of PU Vul obtained at Bohyunsan Astronomy Observatory on April 9, 2004 is presented. At this phase, PU Vul was an emission-line star and its continuum was very weak. Emission lines of He II, H I, [Ne IV], [N II], [O III], [Ar V ] and [Fe VII] dominated the spectrum of PU Vul. Many of them exhibited hat-top profiles with strong and multi-peaked emissions on flat-tops of their profiles. Radial velocities for these lines were measured. Origins of the spectral lines are discussed in terms of the wind and the photoionization models.

• 전기학회논문지
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• 제62권12호
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• pp.1706-1711
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• 2013

This paper presents the filter of a resonator comprising a shorted open gap ring(SOGR) and interdigital lines. The proposed filter has the ultra wideband characteristic operating from 3 GHz to 10.5 GHz. In order to achieve the remarkable improvement in the size-reduction of the overall filter structure, only one cell of the SOGR with the inter-digital lines is adopted. It is shown that this filter has the size of $18mm{\times}15mm$ using a metamaterial, the fractional bandwidth over 100%, the insertion loss much less than 1dB, an acceptable return loss performance in the results.

• 소성∙가공
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• 제33권2호
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• pp.123-131
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• 2024

Plastic, the main material of FFF-type 3D printing, exhibits lower strength compared to metal. research aimed at increasing strength is needed for use in various industrial fields. This study analyzed three X-shape infill patterns(grid, lines, zigzag) with similar internal lattice structure. Moreover, tensile test considering weight and printing time was conducted based on the infill line multiplier and infill overlap percentage. The three X-shape infill patterns(grid, lines, zigzag) showed differences in nozzle paths, material usage and printing time. When infill line multiplier increased, there was a proportional increase in tensile strength/weight and tensile strength/printing time. In terms of infill overlap percentage, the grid pattern at 50% and the zigzag and lines patterns at 75% demonstrated the most efficient performance.

• 천문학회보
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• 제40권2호
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• pp.35.4-36
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• 2015

Gaseous inner disks are the main controller of the final structure of planetary systems as well as the building place of planets, especially of terrestrial planets. However, the inner disk of <5AU is still difficult to be spatially resolved even at the closest star forming regions. Resolving velocity structure in the disk with high resolution infrared spectroscopic study is the best approach to study the inner disk at this moment. Here, we present the IGRINS (Immersion GRating INfrared Spectrometer) result of the Class I young stellar object, ESO Ha 279a, in the Serpens molecular cloud region. IGRINS has a resolving power of R=40,000, corresponding to the velocity resolution of 7 km/s at K-band, which is perfect to study the hot inner disk structure. We report that NaI and CO overtone emission lines are indeed good tracers of the rotating inner warm disk tracing from ~0.04 to ~7AU of this source. We also report the disk properties using other emission lines.

• 한국표면공학회지
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• 제46권4호
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• pp.162-167
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• 2013

Encapsulation is required since organic materials used in OLED devices are fragile to water vapor and oxygen. Laser sealing method is currently used where IR laser is scanned along the glass-frit coated lines. Laser method is, however, not suitable to encapsulating large-sized glass substrate due to the nature of sequential scanning. In this work we propose a new method of encapsulation using Joule heating. Conductive layer is patterned along the sealing lines on which the glass frit is screen printed and sintered. Electric field is then applied to the conductive layer resulting in bonding both the panel glass and the encapsulation glass by melting glass-frit. In order to obtain uniform bonding the temperature of a conductive layer having a shape of closed loop should be uniform. In this work we conducted simulation for heat distribution according to the structure of a conductive layer used as a Joule-heat source. Uniform temperature was obtained with an error of 5% by optimizing the structure of a conductive layer. Based on the results of thermal simulations we concluded that Joule-heating induced encapsulation would be a good candidate for encapsulation method especially for large area glass substrate.

• Nuclear Engineering and Technology
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• 제2권3호
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• pp.163-178
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• 1970

닉켈기 내열합금의 일종인 Rene 41을 76$0^{\circ}C$ 및 87$0^{\circ}C$에서 최고 9300 시간까지 시효열처리한 다음, 5% 내지 20%로 압축변형시켜, 이 합금의 실온에서의 소성변형방식 및 석출입자인 ${\gamma}$'입자와 slip line 간의 상호작용을 전자현미경적 방법으로 관찰연구하였다. 본합금의 slip구조는 $\alpha$황동때와 유사하게｛111｝<110>계에 속하는 단일 slip line으로 구성되어 있었으며, 순알루미늄에서 관찰되는 층상구조는 볼 수 없었다. 또한, slip 구조는 시효조건에 따라 변화한다는 것을 알 수 있었다. 미시효상태뿐만 아니라 과시효상태에 있어서도 Slip line은 여전히${\gamma}$' 석출입자를 통과하였으며, 이 때 석출입자는 지금과 더불어 변형되는 것을 볼 수 있었다. 이 관찰결과를 앞서 발표된 자료와 비교 검토하여 과시효상태에서도 ${\gamma}$'입자는 적어도 일부 지금과 정합되어 있다는 결론을 얻었다.

• 한국조경학회지
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• 제25권4호
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• pp.171-183
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• 1998

The purpose of this study was to analyze urban greenspace area and vegetation structure by land use types for both Chuncheon and Kangleung. Natural and agricultural lands were predominant in the study cites, as 75-80% of total area. Residential lands accounted for about 10%, and commercial and industrial lands(including transportation), 5-10%. Only 10-20% of urban residential and commercial area was covered with greenspace. Woody plant cover was 12-13%, and tree density was 1.5 trees/100$m^2$ for urban lands(all land use types except natural land) in both cities. The tree-age structure was largely characterized by young, growing tree population, and species diversity within a diameter class decreases as the diameter classes get larger. Urban lands of both cities had quite a similar species composition of woody plants (similarity index of 0.65). Street trees in Chuncheon were intensively pruned annually to protect the above ground utility lines. Some strategies were explored to solve problems found in the existing greenspace structures. They included increase of biomass and greenspace area through minimization of unnecessary impervious surfaces, creation of multilayered and multiaged vegetation structures, relocation of above ground utility lines and avoidance of intensive tree pruning, and establishment of greenspace proximity and connectivity.

• 한국작물학회지
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• 제47권1호
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• pp.13-20
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• 2002

Bread baking parameters and relationships between bread baking properties and flour characteristics were evaluated for two years, 1997 and 1998, and at two locations, Suwon and Deokso, with Korean winter wheat cultivars and lines. Among the bread baking parameters, lightness of crumb grain showed differences between years. No significant differences were found in dough mixing time, bread loaf volume, crumb grain score or firmness. Keumkangmil, Suwon 278 and Tapdongmil showed higher bread loaf volume, good structure of crumb grain and softer crumb firmness. However, compared to commercial flours for baking, cultivar means averaged over years and locations of nineteen Korean winter wheats showed poor bread baking quality because of low protein content and unsuitable protein quality. Protein content and flour swelling volume showed better relationships with the bread baking parameters than other flour characteristics. Friabilin-absence lines showed softer crumb firmness than those of friabilin-presence lines.

• 한국항해항만학회지
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• 제31권9호
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• pp.759-762
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• 2007

A novel miniaturized CMOS C-Band bandpass filter based on diagonally end-shorted coupled lines and interdigital capacitors is proposed. The utilized coupled lines structure reduced the configuration in size, as small as a few degrees. Moreover, the characteristic of interdigital capacitor, relatively high Q and good capacitance tolerance, accounts for the satisfied performance of this new filter. A two-stage bandpass filter was designed and fabricated with chip surface area only $1.02{\times}1.4\;mm^2$.