• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2315-2321
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• 2010

Twenty spirodiclofen analogues have been designed and conveniently synthesized via three steps including esterification, one-pot heterocyclization, and acylation reactions. The target molecules have been identified on the basis of analytical spectra ($^1H$ NMR, $^{13}C$ NMR and ESI-MS) data. All newly synthesized compounds have been screened for their potential insecticidal and herbicidal activity by standard method. The preliminary assays indicated that some of analogues displayed moderate to good insecticidal activity against Plutella xylostella compared with spirodiclofen, and some compounds showed obvious activity against Brassica chinensis. Structure-activity relationship (SAR) is also discussed based on the experimental data.

• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.858-862
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• 2015

This paper presents a new forward-viewing mono-camera based obstacle detection algorithm for mobile robots. The proposed method extracts the coarse location of an obstacle in an image using inverse perspective mapping technique from sequential images. In the next step, graph-cut based image labeling is conducted for estimating the exact obstacle boundary. The graph-cut based labeling algorithm labels the image pixels as either obstacle or floor as the final outcome. Experiments are performed to verify the obstacle detection performance of the developed algorithm in several examples, including a book, box, towel, and flower pot. The low illumination condition, low color contrast between floor and obstacle, and floor pattern cases are also tested.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2207-2211
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• 2011

Colloidal cadmium telluride (CdTe) quantum dots (QDs) and their nanoparticles have been synthesized by one pot sonochemical reactions under multibubble sonoluminescence (MBSL) conditions, which are quite mild and facile compared to other typical high temperature solution-based methods. For a typical reaction, $CdCl_2$ and tellurium powder with hexadecylamine and trioctylphosphine/trioctylphosphineoxide (TOP/TOPO) as a dispersant were sonicated in toluene solvent at 20 KHz and a power of 220W for 5-40 min at 60 $^{\circ}C$. The sizes of CdTe particles, in a very wide size range from 2 nm-30 ${\mu}m$, were controllable by varying the sonicating and thermal heating conditions. The prepared CdTe QDs show different colors from pale yellow to dark brown and corresponding photoluminescence properties due mainly to the quantum confinement effect. The CdTe nanoparticles of about 20 nm in average were found to have band gap of 1.53 eV, which is the most optimally matched band gap to solar spectrum.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.153-163
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• 2015

The study was conducted to develop ecological restoration method of damaged area in DMZ vicinities. As the material for the ecological restoration, forest soil and trees waste have been used. Forest soils were collected for experiments in Yanggu, Gangwon Province. Effect of ecological restoration was analyzed through germination experiment. Germination experiment was performed using 12 kinds of woody and herbaceous seeds. Woody and herbaceous seed germination in test pot was relatively evenly. Mixed material consisting of forest soil and trees waste seemed a possibility as the material for the restoration. The effects on seed germination were higher in the case of mixing more than 70% by volume ratio of local resources. Total number germinated individuals were different depending on the mixing ratio of soil sampling depth. Individual plants showed different trends depending on the experimental combination. Results of the woody seed germination were affected only in the soil sampling depth. Seed germination of herbaceous received a combined effect on soil sampling depth and mixing ratio.

• 대한한의학방제학회지
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• 제28권3호
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• pp.281-287
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• 2020

Objectives : In case of herbs decoction, the ceramic or earthware pots was recommended, but not the metals, particularly iron or aluminum, which could cause unknown chemical reactions. In Korean Medical classics, it has been known that some herbs including Caulis Lonicerae Japonicae (CL) were not recommended to boil with iron pot. This study investigates the physical changes of extracts of CL with or without iron. Methods : CL was decocted with reflux cooling extraction system to prevent evaporation and volatilization. Content of polyphenol was detected by Folin-Denis method and the levels of loganin and chlorogenic acid were evaluated by UPLC. Results : The color of extract with glass beads (GB) is yellowish brown, and the iron beads (IB) is blackish brown. Polyphenol and chlorogenic acid levels were reduced in IB extracts. Conclusions : The color of extract was change to blackish brown, and polyphenol and chlorogenic acid levels were reduced in CL extract with iron. Therefore, iron pots is not suitable for CL extraction.

• 한국초지조사료학회지
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• 제7권1호
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• pp.8-17
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• 1987

Four foreign pasture cultivars such as Lotus corniculatus cv. Maitland, Trifolium pratense cv. Deben, Lolium perenne cv. $S_{23}$ and .Dactylis glomerata cv. $S_{26}$ were tested with "Kwisan" series, a common upland soil in Southern part of Korea. The cultivars in single or mixture were grown in pot with two levels of light intensity, i.e. a full sun light condition and 50% interception. Dry matter yield of top and root and their seasonal changes, the number of tillers or branches per plant and finally competative effects of mixtures were evaluated by estimating the expected yield, relative yield totals and compensation index. The results are summarized as follows: 1. Maitland showed a significant decrease in dry matter yield in shade condition, but the number of branches of Maitland was higher than those of Deben. 2. Maitland showed higher dry matter yield than Deben during the mid-summer period, while $S_{23}$, showed higher dry matter yield than $S_{26}$ during early season. 3. Mixtures of $S_{23}$ and Maitland, and $S_{26}$ and Deben gave better response to grasses by increasing the number of tillers in shade condition. 4. Combinations of Lotus corniculatus cv. Maitland and Dactylis glomerata cv. $S_{26}$ and Trifolium pratense cv. Deben and Dactylis glomerata cv. $S_{26}$ gave higher relative yield totals and higher compensation index, which envisages that the pasture establishment rates can be enhanced when those mixtures were sown by the oversowing method in the upland soil where phosphate level is very low and infertile in general.n general.

• 폴리머
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• 제31권5호
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• pp.417-421
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• 2007

덴드리틱 벤질 알코올을 트리에틸아민과 메탄술포닐클로라이드와 반응시켜서, 덴드리틱 벤질 클로라이드의 효율적인 합성이 이루어졌다. 이 반응은 히드록시기의 메실화 반응과 염소화 반응의 2단계 반응으로 이루어지는데, 중간체의 분리없이 한 반응 용기내에서 반응이 진행되는 경제적인 방법이다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2942-2946
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• 2013

Nanostructured Ag thin films could be facilely prepared by soaking glass substrates in ethanolic solutions containing $Ag_2O$ powders at an elevated temperature. The formation of zero-valent Ag was corroborated using X-ray diffraction and X-ray photoelectron spectroscopy. The deposition of Ag onto a glass substrate was readily controlled simply by changing the reaction time. Due to the aggregated structures of Ag, the surface-enhanced Raman scattering spectra of benzenethiol could be clearly identified using the Ag-coated glass. The enhancement factor at 514.5 nm excitation estimated using benzenethiol reached $1.0{\times}10^5$ while the detection limit of rhodamine 6G was found to be as low as $1.0{\times}10^{-13}$ M. Since this one-pot fabrication method is eco-friendly and is suitable for the mass production of diverse Ag films, it is expected to play a significant role in the development of surface plasmon-based analytical devices.

• Environmental Engineering Research
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• 제24권4호
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• pp.566-571
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• 2019

One-pot hydrothermal route was adopted to synthesize Al:BiVO₄, at 4 h and 8 h reaction durations, by adding 1% aluminiumoxide powder (w/v) to the precursors. The products were investigated using several characterization techniques that conform a significant morphological change and a decrease in bandgap energy of the materials upon Al modification of scheelite monoclinic bismuth vanadate matrix at both hydrothermal durations. Antibacterial experiments were performed against methicillin-resistant Staphylococcus aureus in visible light condition to harness the photoxidation property of Al-doped BiVO₄ and compare to that of unaltered BiVO₄. Minimum inhibitory concentration of the synthesized materials was identified. The results indicate that Al-doping on BiVO₄ has a significant effect on its photocatalytic antibacterial performance. Al:BiVO₄ synthesized at 8 h hydrothermal treatment parades excellent sunlight-driven photocatalysis compared to the one synthesized at 4 h.

• 한국해안·해양공학회논문집
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• 제23권4호
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• pp.265-275
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• 2011

방파제 등 항만 외곽시설의 설계에 있어서 파랑은 구조물의 단면을 결정하는 가장 중요한 요소이다. 본 연구에서는 Holland(1980)의 파라미터 모델을 이용하여 태풍시의 해상풍을 구축하고, WAM 모형을 이용하여 태풍에 의한 파랑을 수치 계산하였다. 남해안의 부산, 목포, 여수, 서귀포 지역에 영향을 미친 태풍을 선정하고 가상의 태풍을 추가하여 training set을 구성하고, 남향 계열의 7개 파향에 대해서 경험모의기법을 적용하여 재현기간별 설계 파고를 산정하였다. 또한, 이를 POT 방법과 한국해양연구원(2005)의 결과와 비교, 분석하였다.