• 생약학회지
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• 제19권1호
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• pp.34-38
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• 1988

Veronicastrum species are perennial herb growing on the moisty land. They involves on species (V. sibiricum, Naeng-Cho), one subspecies (V. sibiricum var. zuccarini, Tuel-Naeng-Cho) and one variety (V. sibiricum var. zuccarini for. albiflora). This paper deals with a comparison of the chemical components between Naeng-Cho and Tuel-Naeng-Cho.) In the specified HPLC condition used with ${\mu}BondapakC_{18}\;column$, the retention time of aucubin, catalpol, minecoside and veratryl catalpol ester were 2.30, 2.65, 3.05 and 3.10 min, respectively, and in the other condition used with ${\mu}Bondapak\;C_8-NH_2$, the retention time of aucubin, catalpol, minecoside and veratryl catalpol were 5.4, 5.4, 4.4 and 3.2 min, respectively. The contents of minecoside in Tuel-Naeng-Cho were found to be 3.5 and 1mg/g of dry plant material and that of catalpol were found to be 5 and 2 mg/g, respectively.

• 한국식품과학회지
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• 제34권6호
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• pp.1145-1148
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• 2002

뇌의 송과선에서 분비되는 호르몬인 melatonin은 생체의 산화적 손상을 방어하는 효능이 있다고 알려져 있는데, 26종의 식물체로부터 그 존재 및 함량을 분석하였다. Melatonin 함유 분획을 조제하기 위하여 동결건조된 식물체 분말을 50% ethanol로 추출한 다음 여과 후 TLC 상에서 acetone으로 전개시켜 melatonin을 분리하였다. 형광하에서 확인된 melatonin spot은 methanol로 추출한 다음 HPLC로 분석하였다. HPLC 분석시 ODS-A column을 사용하였으며 이동상은 70% ammonium acetate와 메탄올을 30 : 70(v/v)으로 섞어서 1.0 mL/min의 속도로 흘려주었다. Melatonin peak의 확인은 형광 detector를 이용하였으며 retention time은 17분이었다. 이같은 분석조건에서 셀러리, 부추, 브로콜리, 컬리플라워 등에서 높은 melatonin 함량이 확인되었다.

• 한국물환경학회지
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• 제35권4호
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• pp.332-339
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• 2019

A comparative study on the anaerobic digestion efficiency according to the temperature change was conducted considering the characteristics of domestic food wastes with high water content of about 80 % or more. The substrate was tested for anaerobic digestion efficiency in two substrates, a liquid component separated naturally from food waste and food waste itself. In the anaerobic digestion experiments, the digestion efficiency was the highest at $55^{\circ}C$ (thermophilic temperature). However, the digestion efficiency at $45^{\circ}C$(middle high temperature) was lower than that at $35^{\circ}C$(mesophilic temperature). The comparison of general food wastes anaerobic digestion requiring 30 days of hydraulic retention time to the liquid component indicated a stable digestion efficiency even after 15 days of hydraulic retention time.In the experiments conducted on food waste, the digestion efficiency at $55^{\circ}C$ was higher than that at $35^{\circ}C$. When the food waste, especially the liquid component originating from food waste, is treated by anaerobic digestion method, the mesophilic temperature and thermophilic temperature conditions are more favorable in the digestion efficiency than the middle high temperature ($45^{\circ}C$). However, when applying thermophilic or mesophilic temperature anaerobic digestion process operation in the field, the amount of energy input should be considered.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.554-556
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• 2022

최근 1인 가구의 급증에 따라 고독사가 중요한 사회 문제로 주목받고 있다. 본 논문에서는 고독사 위험에 노출된 사회적 약자들을 보호하기 위하여 RFID를 활용한 적응형 모니터링 시스템을 개발한다. 개발된 시스템은 웨어러블 RFID 태그, 주거지 내 부착된 RFID 리더기, 사용자 모니터링 앱으로 구성된다. 개발된 시스템은 웨어러블 태그를 지닌 사용자가 리더기가 부착된 장소에 머무는 시간을 측정하고, 적응적으로 결정된 임계치를 초과할 때 보호자에게 긴급 알림을 전송한다. 아두이노를 기반으로 거주지를 모델링한 프로토타입을 구현함으로써 설계된 시스템의 효용성을 검증하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.53-53
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• 2009

Charge trap flash memory devices with modified tunneling barriers were fabricated using the tunneling barrier engineering technique. Variable oxide thickness (VARIOT) barrier and CRESTED barrier consisting of thin $SiO_2$ and $Si_3N_4$ dielectric layers were used as engineered tunneling barriers. The VARIOT type tunneling barrier composed of oxide-nitride-oxide (ONO) layers revealed reliable electrical characteristics; long retention time and superior endurance. On the other hand, the CRESTED tunneling barrier composed of nitride-oxide-nitride (NON) layers showed degraded retention and endurance characteristics. It is found that the degradation of NON barrier is associated with the increase of interface state density at tunneling barrier/silicon channel by programming and erasing (P/E) stress.

• Membrane and Water Treatment
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• 제2권1호
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• pp.63-74
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• 2011

A spiral wound nanofiltration (NF) membrane (GE Osmonics, DK 4040F) was used to remove pesticides from water. Several solutions of single pesticides and their mixtures were prepared. The pesticides initial concentration ranged from ca. 50 ng/L (single pesticide) to ca. 700 ng/L (as sum of 14 pesticides) and progressively increased with time since the NF experiments were carried out in a concentration mode up to a Volume Concentration Ratio, VCR = 10. Permeate flux and pesticides retention were evaluated as a function of the Volume Concentration Ratio. The permeate flux did not practically change by varying VCR. Pesticide retention was found to be around 97-98% both in the cases of single pesticide solutions and different mixtures of pollutants, and was not affected by the VCR. Pesticides concentration in permeate samples was found to be lower than the maximum concentration level fixed in European directive.

• 한국전기전자재료학회논문지
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• 제18권3호
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• pp.193-198
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• 2005

NOR type flash 32 ${\times}$ 32 way are fabricated by using the typical 0.35 ${\mu}{\textrm}{m}$ CMOS process. The structure of array is the NOR type with common source line. In this paper, optimized program and erase voltage conditions are presented to realize multi-bit per cell at the CSL-NOR array. These are considered selectivity of selected bit and disturbances of unselected bits. Retention characteristics of locally trapped-charges in the nitride layer are investigated. The lateral diffusion and vertical detrapping to the tunneling oxide of locally trapped charges as a function of retention time are investigated by using the charge pumping method. The results are directly shown by change of the trapped-charges quantities.

• Transactions on Electrical and Electronic Materials
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• 제16권5호
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• pp.290-292
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• 2015

We have reported about bipolar resistive switching effect on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]:Graphene oxide composite films, which are sandwiched between aluminum and indium tin oxide electrodes. In this case, I-V sweep curve showed a hysteretic behavior, which varied according to the polarity of the applied voltage bias. The device exhibited excellent switching characteristics, with the ON/OFF ratio being approximately two orders in magnitude. The device had good endurance (10⁵ cycles without degradation) and long retention time (5 × 10³ s) at room temperature. The bistable switching behavior varied according to the trapping and de-trapping of charges on GO sites; the carrier transport was described using the space-charge-limited current (SCLC) model.

• 펄프종이기술
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• 제36권1호
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• pp.67-74
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• 2004

This study was carried out to investigate the characteristics of handsheets made from nonwoody New-Zealand hemp (Phormium tenax) fibers that was not used before in Korea. The results were as follows : 1. Physical properties of bleached phormium fiber were satisfactory for handsheet forming. Specially, tensile strength was improved by adding bleached phormium fiber. 2. Opacity of handsheet with phormium pulp was fine, therefore it can be useful fiber to improve opacity of light-weight printing paper. 3. Filler retention rate was improved when phormium pulp was added, while drainage time was increased. 4. Phormium fiber has good characteristics as pulp for paper manufacture. So it can be valuable non-wood fiber resource if drainage problem is solved.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.89-94
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• 1999

The workability of high strength concrete using high range water reducing admixture is varied rapidly according to elapsed time. For using the high strength concrete in situ, careful caution on workability is necessary. By using fly ash as a admixture, the slump loss of concrete can be reduced considerably, but the early strength of concrete used fly ash is smaller than that not used fly ash. For the purpose of elevating the utilization of fly ash on high strength concrete, the high fluidity retention and the strength development in early age are necessary in concrete used fly ash. In this study, to improve the fluidity retention and to acquire strength development on concrete used fly ash, the gypsum is applied.