• Advances in nano research
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• 제13권1호
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• pp.1-12
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• 2022

The existence of active material in the environment causes the small-scale systems to be sensitive to the actual environment. Carbon dioxide is one of the active materials that exists a lot in the air conditions of the living environment. However, in some applications, the carbon dioxide-coated is used to improve the performance of systems against the destructive factors such as the corrosion; nevertheless, in the current research, the stability analysis of a carbon dioxide capture mechanism-coated beam is investigated according to the mathematical simulation of a rectangular composite beam utilizing the modified couple stress theory. The composite mechanism of carbon dioxide trapping is made of a polyacrylonitrile substrate that supports a cross-link polydimethylsiloxane gutter layer as the carbon dioxide mechanism trapping. Three novel types of carbon dioxide trapping mechanism involving methacrylate, poly (ethylene glycol) methyl ether methacrylate, and three pedant methacrylates are considered, which were introduced by Fu et al. (2016). Finally, according to introducing the methodology of carbon dioxide (CO₂) trapping, the impact of various effective parameters on the stability of composite beams will be analyzed in detail.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.268.1-268.1
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• 2013

Immobilization of conducting nanoparticles on a nanogap comprising two electrodes spaced at a distance comparable to the particle size can be used as a simple and sensitive method of detecting the particles. In this work, we have examined the performance of the nanogap devices in the measurement of metallic nanoparticles, particularly gold nanoparticles (Au NPs). Detection of pM-level Au NPs in an aqueous suspension was quite straightforward irrespective of the existence of non-conducting materials. Speed of detection or the time necessary for the completion of the measurement, however, was strongly dependent upon the immobilization process. Active trapping process was found to be much more efficient and also effective in the detection of nanoparticles than its passive counterpart.

• Natural Product Sciences
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• 제23권4호
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• pp.247-252
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• 2017

The methylglyoxal (MGO) trapping constituents from onion (Allium cepa L.) peels were investigated using pre-column incubation of MGO and crude extract followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Among major constituents in outer scale of onion, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2) was more effective MGO scavenger than quercetin (6) and its 4'-glucoside, spiraeoside (3). After 1 h incubation, compound 2 trapped over 90% MGO at a concentration of 0.5 mM under physiological conditions, but compounds 3 and 6 scavenged 45%, 16% MGO, respectively. HPLC-ESI/MS showed that compound 2 trapped two molecules of MGO to form a di-MGO adduct and compounds 3 and 6 captured one molecule of MGO to form mono-MGO adducts, and the positions 6 and 8 of the A ring of flavonoids were major active sites for trapping MGO.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.160.3-161
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• 2003

Aldehyde and active form of free oxygen produced in alcohol metabolism in liver are the cause of liver cell damage. The main system of alcohol metabolism is composed of alcohol dehydrogenase(ADH), aldehyde dehydrogenase(ALDH) and cytochrome P4502E1. Alcohol dehydrogenase is reversible in alcohol metabolism. To block the backward reaction and enhance alcohol oxidation, acetaldehyde trapping agents were assayed. The assay was carried out by measuring decreasing NADH at 340nm, using acetaldcehyde and NADH as substrate and coenzyme respectively. (omitted)

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1907-1910
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• 2004

Generation of hydroxyl radical, one of their major active species in ozonation of water was directly observed with spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-pyrrolidine-1-oxyl (DMPO) as a spin-trapping reagent. Hydroxyl radical was trapped with DMPO as a stable radical, DMPO-OH. 80 mM of ozone produced $1.08{\times}10^{-6}$M of DMPO-OH, indicating that 1.4% of ${\cdot}$OH is trapped with DMPO if ${\cdot}$OH is produced stoichiometrically from ozone. Humic acid suppressed DMPO-OH generation in a dose-dependent manner. Generation rate of DMPO-OH was determined with ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance·OH generation during ozonation of water.

• Natural Product Sciences
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• 제27권4호
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• pp.245-250
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• 2021

The methylglyoxal (MGO) trapping constituents from Malus baccata L. were investigated using incubation of MGO and crude extract under physiological conditions followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Sieboldin was identified as a major active molecule representing MGO-trapping activity of the crude extract. After reaction of sieboldin and MGO, remaining MGO was calculated by microplate assay method using imine (Schiff base) formation of 2,4-dinitrophenylhydrazine (DNPH) and aldehyde group. After 4 h incubation, sieboldin trapped over 43.8% MGO at a concentration of 0.33 mM and showed MGO scavenging activity with an RC₅₀ value of 0.88 mM for the incubation of 30 min under physiological conditions. It was also confirmed that sieboldin inhibited the production of advanced glycation end products (AGE) produced by bovine serum albumins (BSA)/MGO. Additionally, MGO trapping mechanism of sieboldin was more specifically identified by ¹H-, ¹³C-, 2D NMR and, confirm to be attached to the position of C-3' (or 5').

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.90.2-90.2
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• 2010

The crystalline silicon solar cells have been optical losses. but it can be reduced using light trapping by texture structure and anti-reflection coating. The high reflective index of crystalline silicon at solar wavelengths(400nm~1000nm) creates large reflection losses that must be compensated for by applying anti-reflection coating. In this study, the use of porous silicon(PSi) as an active material in a solar cell to take advantage of light trapping and blue-harvesting photoluminescence effect. Porous silicon is form by anodization and can be obtained in an electrolyte with hydrofluoric. We expect our research can results approaching to lower than 10% of several reflectance by porous silicon solar cells.

• 한국응용곤충학회지
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• 제60권4호
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• pp.369-377
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• 2021

꽃노랑총채벌레(Frankliniella occidentalis) 방제 전략 가운데 하나로 대량유살 기술이 제기되었다. 이를 위해 본 연구는 이 해충에 적용되는 상용유인제의 효능을 시설 고추재배지를 중심으로 분석하였다. 총채벌레 모니터링에 사용되는 점착트랩의 경우 청색과 황색 색상에 따른 유인력 차이는 크지 않았다. 그러나 트랩의 위치는 큰 변수로서 기주에 가까이 위치할수록 포획 밀도가 높았다. 또한 상하 위치도 중요한 변수로서 기주 작물 수관 부위에서 가장 높은 포획 밀도를 보였다. 이를 기준으로 황색 점착 트랩을 설치한 경우 전체 총채벌레 밀도의 약 1%를 유살하였다. 이러한 낮은 유살 능력을 높이기 위해 상용유인제를 황색트랩에 추가하였다. 집합페로몬 또는 식물 휘발성 유인제(4-methoxybenzaldehyde) 성분의 두 가지 상용유인제 추가 처리는 황색트랩 단독 처리에 비해 크게 유인력을 증가시키지 못하였다. 그러나 Y-튜브 실내 행동분석은 집합페로몬과 식물 휘발성 유인제(methyl isonicotinate)들이 각각 꽃노랑총채벌레에 대해서 높은 유인력을 가지고 있는 것을 확인하였다. 반면에 이들 유인물질 은 기주 고추 꽃보다 꽃노랑총채벌레에 대해서 상대적으로 낮은 유인력을 나타냈다. 이는 꽃이 없는 시설 대파(Allium fistulosum) 재배지에서는 상용유인제 추가 처리가 황색트랩 단독 처리보다 꽃노랑총채벌레에 대하여 높은 유인력을 가지는 것을 미뤄 이 곤충의 꽃에 대한 높은 선호성을 뒷받침하였다. 본 연구는 꽃노랑총채벌레에 사용되는 상용유인제들의 한계성을 지적하며 추후 고추 꽃을 중심으로 새로운 유인물질의 탐색에 대한 기초자료를 제공한다.

• 전기학회논문지
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• 제56권1호
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• pp.112-116
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• 2007

We have investigated the hysteresis phenomenon of a hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and analyzed the effect of hysteresis phenomenon when a-Si:H TFT is a pixel element of active matrix organic light emitting diode (AMOLED). When a-Si:H TFT is addressed to different starting gate voltages, such as 10V and 5V, the measured transfer characteristics with 1uA at $V_{DS}$ = 10V shows that the gate voltage shift of 0.15V is occurred due to the different quantities of trapped charge. When the step gate-voltage in the transfer curve is decreased from 0.5V to 0.05V, the gate-voltage shift is decreased from 0.78V to 0.39V due to the change of charge do-trapping rate. The measured OLED current in the widely used 2-TFT pixel show that a gate-voltage of TFT in the previous frame can influence OLED current in the present frame by 35% due to the change of interface trap density induced by different starting gate voltages.

• Journal of Life Science
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• 제12권2호
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• pp.75-79
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• 2002

Tea catechins, the most important compounds in tea polyphenols, can efficiently scavenge superoxide anion free-radical ($O_2$.), hydroxyl radical. (.OH) The mechanism of scavenging active oxygen free radicals was investigated by ESR spin trapping technique and Chemiluminescence. Results showed that various tea catechins constitute an antioxidant cycle in accordance with the decreasing order of the first reductive potential, and produce the effect of cooperative strength each other. Esterificated catechins could scavenge active oxygen free radicals more effectively than the non-esterificated ones. When.OH and $O_2$.- were scavenged by (-)-epigallocatechin gallate [(-)- EGCG], the stoichiometric factors were 6, and the rate constants of scavenging reaction reached $7.71{\times}10^6$ and $3.52{\times}10^{11}$ L $mmol^{-1}s^{-1}$, respectively. In the mean time, tea catechins could scavenge superoxide anion fiee radical ($O_2$-.) and hydroxyl radical (.OH) in a dose dependent manner. But at higher concentration or pH value, tea catechins can induce the prooxidant.