• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.491-500
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• 2004

The Lewis acid-catalyzed reactions of anthrone with a variety of ethylenic substrates under various conditions have been studied. It has been observed that depending on kinds of ethylenic substrates and catalysts, products were varied. In particular, the $ZnCl_2$-catalyzed reaction of anthrone with ${\alpha},{\beta}$ -unsaturated ester gave bridged compounds 3 (Diels-Alder adduct type) and mono-Michael adduct 4 exclusively, while the base-catalyzed reaction gave 10,10-bis-Michael adduct as a major product independent of the amount of ethylenic substrate and base. Bridged compounds 3 were easily converted to the corresponding mono-Michael adduct 4 by a catalytic amount of base. Further Michael reaction of mono-Michael adducts with different ethylenic substrates in the presence of a catalytic amount of alkoxide gave unsymmetrical 10,10-bis Michael adducts in good or moderate yields.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.343-349
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• 2006

Systematic experiments in $CH_4/Air$ counterflow diffusion flames diluted with He have been undertaken to study the oscillatory instability in which lateral flame size was less than burner nozzle diameter and thus lateral heat loss could be remarkable at low global strain rate. The oscillatory instability arises for Lewis numbers greater than unity and occurs near extinction condition. The oscillation is the direct outcome from the advancing and retreating edge flame. The dynamic behaviors of extinction in this configuration can be classified into three modes; growing, harmonic and decaying oscillation mode near extinction. As the global strain rate decreases, the amplitude of the oscillation becomes larger. This is caused by the increase of lateral heat loss which can be confirmed by the reduction of lateral flame size. Oscillatory edge flame instabilities at low global strain rate are shown to be closely associated with not only Lewis number but also heat loss (radiation and lateral heat loss).

• Korean Journal of Clinical Pharmacy
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• v.24 no.4
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• pp.240-247
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• 2014

Objective: Undernutrition is common amongst esophageal cancer patients and therefore appropriate nutrition support is critical. Nevertheless, the effectiveness of enteral nutrition (EN) versus parenteral nutrition (PN) is still controversial. The aim of this study was to investigate the effect of EN and PN on the nutritional state and the length of hospital stay for patients who underwent an Ivor-Lewis (IL) esophagectomy. Method: A retrospective clinical analysis was performed that utilized the electronic medical records of patients who underwent IL esophagectomy during a 3-year period between January 2010 and December 2012 at a tertiary teaching hospital located in Seoul, Korea. The EN group and PN group were analyzed by comparing the nutrition supply, postoperative complications, length of hospital stay, and weight variation. Results: After an IL esophagectomy, the complication rate between the EN group and PN group was insignificant and the length of hospital stay was significantly shorter for the PN group compared to the EN group (14 vs. 16 days, respectively; p<0.001). At the time of discharge, those in the PN group lost less weight postoperatively (p=0.003). Conclusion: PN may be considered as safe nutrition support for esophageal cancer patients who underwent an esophagectomy.

• Journal of the Korean Society of Combustion
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• v.16 no.2
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• pp.23-32
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• 2011

To investigate cell formation in hydrocarbon/hydrogen/carbon monoxide-air premixed flames, the outward propagation and cellular instabilities were experimentally studied in a constant pressure combustion chamber at room temperature and elevated pressures. Unstretched laminar burning velocities and Markstein lengths of the mixtures were obtained by analyzing high-speed schlieren images. In this study, hydrodynamic and diffusional- thermal instabilities were evaluated to examine their effects on flame instabilities. The experimentally-measured unstretched laminar burning velocities were compared to numerical predictions using the PREMIX code. Effective Lewis numbers of premixed flames with methane addition decreased for all of the cases; meanwhile, effective Lewis numbers with propane addition increased for lean and stoichiometric conditions and increased for rich and stoichiometric cases for hydrogen-enriched flames. With the addition of propane, the propensity for cell formation significantly was diminished, whereas cellular instabilities for hydrogen-enriched flames were promoted. However, similar behavior of cellularity was obtained with the addition of methane to the reactant mixtures.

• Journal of the Korean Society of Combustion
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• v.17 no.4
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• pp.51-59
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• 2012

Experimental study in coflow jet flames has been conducted to investigate the helium-dilution effect of coflow air on self-excitation. For various helium mole fractions and jet velocities, two types of self-excitation were observed: buoyancy-driven self-excitation and Lewis-number-induced self-excitation(here after called Le-ISE) coupled with buoyancy-driven one. The difference between buoyancy-driven and Le-ISE is clarified by using the Mie-scattering visualization as well as exploring the different features. The mechanism of Le-ISE is proposed. When the system Damk$\ddot{o}$hler number was lowered, Le-ISE is shown to be launched. Le-ISE is closely related to heat loss, in that it can be launched in even methane jet flame (Lewis number less than unity) with helium-diluted coflow air. Particularly, Le-ISE becomes significant as the Damk$\ddot{o}$hler number decreases and heat-loss becomes significant.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.911-914
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• 1998

We report our experience with 2 cases of perforation of intrathoracic stomach after Ivor Lewis operation for esophageal cancer. There was no problem in the anastomotic site, but the drainage from pleural cavity increased after oral intake. The stomach perforation was proved by rethoracotomy. The perforation site was repaired by sutures with pedicled intercostal muscle.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.456-456
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• 2012

한강유역에 위치한 247개의 강우계에서 관측된 강우 자료를 분석하여 Modified Bartlett-Lewis Retangular Pulse Model (MBLRPM)의 매개변수들을 산정하고, 이들의 지도를 작성한 후, 이들의 정확도 및 매개변수들의 시/공간적 변화 유형을 분석하였다. 이를 위한 첫번째 과정으로, 각 강우 게이지에 대해 MBLRPM의 매개변수에 사용되는 통계치 (각 달에 대한 1, 3, 12, 24시간 누적 수준에서의 평균, 분산, 자기 상관계수, 무강우 확률)들을 계산한다. 이 후, 격자화된 한강유역의 각 셀에 대하여 앞서 계산된 강우 통계치를 Ordinary Kriging 공간 보간법을 통하여 할당한다. 이 후, 각 셀에 할당된 강우 통계치를 사용하여 MBLRPM의 매개변수들을 산정하여 각 매개변수들의 지도를 각 달에 대하여 얻는다. 매개변수 지도를 사용하여 MBLRPM에 의해 생성된 강우 데이터들은 관측치의 통계치를 정확성있게 재현하였으며, 시/공간적 경향성을 분석한 결과, 강우세포의 지속기간과 관련된 매개 변수를 제외한 나머지 5개의 매개변수들은 확연한 공간적 경향성을 보인 한 편, 시간적 경향성은 잘 나타나지 않았다. 본 연구 결과는 매개변수 산정이 힘든 MBLRPM의 특성을 극복하게 해주어 가상 강우 생성을 용이하게 함으로써 강우에 영향을 받는 여러 종류의 연구 주제에 대해 불확실성 분석을 할 수 있게 한다는 점에서 의미를 가질 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.341-341
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• 2012

최근 기후변화로 인한 이상호우의 발생으로 도시유역에서의 홍수피해가 급증하고 있으며 이로 인해 도시유역에서의 설계홍수량 산정이 매우 중요시 되고 있다. 지금까지는 도시유역에서의 설계홍수량을 산정하기 위해 I-D-F 곡선을 이용하고 있으나 현실적으로 시간단위 이하의 관측강우량 자료의 부족으로 인해 신뢰성 있는 시간단위 이하의 설계강우량 산정에 많은 불확실성을 지니고 있다. 도시유역의 경우에는 자연유역에 비해 강우발생시 일반적으로 도달시간이 한 시간 이하이기 때문에 극한 강우사상 즉, 단시간에 집중적으로 많은 양의 강우가 발생 할 경우 시간단위 이하의 강우강도를 이용한 유출해석이 필요하다. 따라서 본 연구에서는 추계학적 강우발생기법을 통해 시간단위 강우시계열자료를 확충한 후 분해기법을 통해 시간단위이하강우를 생성하였다. 이를 위해 Bartlett-Lewis rectangular pulse 모형과 Cascade 분해 기법을 이용하여 5분단위 강우량자료를 모의발생 하였다. 또한 모의치와 관측치를 재현기간별로 비교, 분석하여 그 차이를 확인하였다.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.683-687
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• 2019

The leafhopper genus Batracomorphus Lewis, 1834 belongs to the tribe Batracomorphini (Hemiptera: Auchenorrhyncha: Cicadellidae: Iassinae). B. irroratus Lewis, 1834 was designated as its type species. The genus includes most diverse species in the subfamily Iassinae and contains approximately 350 described species from the world. In Korea, four Batracomorphus species, B. allioni (Turton, 1802), B. punctilliger Anufriev, 1981, B. stigmaticus (Matsumura, 1912), B. viridulus (Melichar, 1902), have been reported in the Korean peninsula. The members of this genus have a similar body size and similar general appearances; thus, it is very difficult to identify clearly without examining the male's genital structures. In this study, Batracomorphus furcatus Li and Wang, 2003 is newly reported from Korea for the first time. This species is previously known to be from China. Herein, the morphological information of B. furcatus Li and Wang is provided with a re-description, photographs of the male dorsal habitus, illustrations of the genitalia structure and distributional records. In addition, a key to the Korean five species of Batracomorphus is presented.

• Biomedical Science Letters
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• v.26 no.4
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• pp.267-274
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• 2020

The larva of Protaetia brevitarsis Lewis (P. brevitarsis), edible insect, is traditionally consumed as alternative source of nutrients and has various health benefits. However, the exact pharmaceutical effects of P. brevitarsis on inflammatory response are still not well understood. Thus, we investigated the anti-inflammatory effects and mechanisms of P. brevitarsis in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. We investigated the effects of P. brevitarsis on the expression levels of inflammatory-related genes, including inflammatory cytokines, prostaglandin E2 (PGE2), cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. To understand the anti-inflammatory mechanism of P. brevitarsis, we explored the regulatory effect of P. brevitarsis on nuclear factor (NF)-κB and caspase-1 activation. The findings of this study demonstrated that P. brevitarsis inhibits the LPS-induced inflammatory cytokine and PGE2 levels, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory effect of P. brevitarsis occurs via suppression of the activation of NF-κB and caspase-1. Conclusively, these findings provide experimental evidence that P. brevitarsis may be useful candidate for the treatment of inflammatory-related diseases.