• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.472-485
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• 2019

When wood plastic composites (WPCs) have been used for a certain period of time, they become waste materials and should be recycled to reduce their environmental impact. Waste WPCs can be transformed into reinforced composites, in which fillers are used to improve their performance. In this study, recycled WPCs were prepared using different proportions of waste WPCs, nanoclay, and glass fiber. The effects of nanoclay and glass fiber on the microstructural, mechanical, thermal, and water absorption properties of the recycled WPCs were investigated. X-ray diffraction showed that the nanoclay intercalates in the WPCs. Additionally, scanning electron micrographs revealed that the glass fiber is adequately dispersed. According to the analysis of mechanical properties, the simultaneous incorporation of nanoclay and glass fiber improved both tensile and flexural strengths. However, as the amount of fillers increases, their dispersion becomes limited and the tensile and flexural modulus were not further improved. The synergistic effect of nanoclay and glass fiber in recycled WPCs enhanced the thermal stability and crystallinity ($X_c$). Also, the presence of nanoclay improved the water absorption properties. The results suggested that recycled WPCs reinforced with nanoclay and glass fiber improved the deteriorated performance, showing the potential of recycled waste WPCs.

• 한국환경복원기술학회지
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• 제2권3호
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• pp.18-24
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• 1999

본 연구는 인공지반의 녹화에 보편적으로 이용되고 있는 자연토양, 개량토양, 인공토양에 따른 식물의 생육상태를 밝히기 위해 몇 가지 토양을 배합조성하고 이에 따른 목본식물(자산홍)의 생장상태를 측정하여 다음과 같은 결론을 얻었다. 먼저 토양종류에 따른 목본식물의 생장인자 간에 상관분석을 실시한 결과 지하부의 생장은 공극량 등이 중요하게 관여하고 있으며, 지상부의 경우는 전질소비가 생장에 중요한 영향요인으로 작용되고 있는 것으로 나타났다. 토양재료중 자연토양(밭흙)은 지상의 생장(수고, 엽수, 엽폭, 절화수)과 지상부의 건물중, 지하부의 건물중 모두 가장 저조한 것으로 나타났다. 인공토양(버미큘라이트)은 지상의 생장(수고, 엽수, 엽폭, 절화수 등)은 좋지 않았으나 상대적으로 지하부의 건물중이 월등히 높았으며 이러한 지하부의 우수한 생육에 기인하여 총건물중도 가장 높게 나타났다. 따라서 인공토양인 버미큘라이트의 경우 지닌 양분이 미약하여 지상의 생육상태는 양호하지 못했으나 통기성 및 투수성 등이 좋아 지하부의 생육에 결정적인 영향을 미친 것으로 판단된다. 밭흙을 주재료로 한 개량토양 중 버미큘라이트와 훈탄을 배합한 처리구는 지상부, 지하부 모두 중간정도의 생장상태를 나타냈다. 부숙톱밥을 혼합한 개량토양의 경우 총건물중은 인공토양(버미큘라이트) 다음으로 높았으며 나머지 수고, 엽수, 엽폭, 절화수 및 지상부의 건물중 등 지상부의 생장상태는 가장 좋은 것으로 나타났다. 특히 유기물 재료 중에서도 훈탄보다는 부숙톱밥이 들어간 배합토에서 생육이 좋은 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1593-1595
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• 1999

Effects of carbon black species and concentration on the mechanical and electrical properties of alumina trihydrate filled EPDM compounds were investigated. Mechanical properties improved with increasing carbon black concentration, and these effects were prominent in carbon blacks haying large specific area. In the case of non-conductive carbon black. tracking resistance improved when a small amount of carbon black was added to EPDM. Conductive carbon black showed detrimental effect to dielectric losses, volume resistivity and tracking resistance of EPDM compound.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.97-100
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• 2006

The efforts have improved the absorbtion that in order to high the quality of recycled aggregates, and the shape. For the shape of recycled aggregates, the shape of usually aggregates can affect the strength of concrete in an indirect way. So that, in the study, effects is investigated the shape of recycled aggregates that affects the compressive strength and slump. In the result, the a improved shape have a beneficial effect on compressive strength and slump for of a high quality recycled aggregate, and these appear a larger effects in unit water ; $175kg/m^3$ or specified strength ; 24MPa.

• Asian-Australasian Journal of Animal Sciences
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• 제8권6호
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• pp.607-610
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• 1995

An experiment was conducted to study the effects of Ascorbic Acid (AA) supplementations in the layer and broiler diets kept in the natural hot humid tropical climate ($20-35^{\circ}C$). The layers and the broilers were fed on normal commercial diet as control while supplementation of 400 and 600 mg/kg Ascorbic Acid made up the experimental diets. The results showed that AA supplementation in the layers significantly reduced egg weight and increased Haugh unit values of the eggs, but produced no significant effects on feed intake, body weight, egg production, respiratory rate and body temperature. The shell thickness was slightly improved, though not significantly, with AA supplementation. AA supplementation in broilers improved body weight gain and FCR and reduced the effect of heat stress as shown by lower body temperature and respiratory rates.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.973-980
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• 2004

Phase I clinical trials are often pharmacologically oriented and usually attempt to find the best dose of drug to employ. However, other purposes like determination of sizes and types of side effects and toxicity and organ system involved are equally important. Estimation of treatment effects or side effects is usually ignored since it is usually based on too small sample, even though Phase II clinical trials would be designed based on the Phase I studies. Statistical methods for constructing the approximate confidence interval for population median in case of small sample are considered and an improved method is proposed. The proposed estimator is compared with current methods through simulation studies.

• Current Research on Agriculture and Life Sciences
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• 제19권
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• pp.9-16
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• 2001

This study addressed the effects of environmental attitude improved using forest environmental interpretation program. While previous research has focused developing interpretation program itself, this study analyzed the effects that environmental interpretation has improved toward pro-environmental attitude. This program was designed self-guiding interpretive techniques at Mt. Palgongsan Provincial Park. Environmental attitude was measured using 12 statements which was based on fifth-graders attitude scale in U.S.A. Data were collected from 84 elementary school participants in this program. Results showed that attitude scores of participants increased toward pro-environmental attitude. Especially, three statements (interest, safe and benefits of forest) are statistically significant differences between pre- and post survey. Results can be used by outdoor educators to evaluate and plan their environmental interpretation programs and methods.

• 대한안전경영과학회지
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• 제13권4호
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• pp.207-212
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• 2011

Taguchi's robust design methodology has focus only a single characteristic or response, but the quality of most products is seldom defined by a characteristics, and is rather the composite of a family of characteristics which are often interrelated and nearly always measured in a variety of units. The multiple characteristics problem is how to compromise the conflicts among the selected levels of the design parameters for each individual characteristic. This paper presents a Taguchi-like approach based upon improved weighted main effects. One case study is solved by the proposed method.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.8-14
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• 2008

This paper studies a more exact flicker evaluation method by detecting power quality disturbances and excluding the effects of power quality disturbances. Up to the present, power quality disturbances affect flicker evaluation index because power quality problems do not have been considered. However, flick index should represent only flicker without power quality disturbances. Thus, in this paper, we present the improved flicker evaluation method which removing the effects of power quality disturbances such as voltage sag and transient caused by fault and inverter/breaker switching. We detect voltage sag and transient using wavelet transform and remove the effects of power quality disturbances from flicker index.

• 대한한방내과학회지
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• 제41권3호
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• pp.424-433
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• 2020

Qingfei Paidu decoction is recommended for treatment and prevention of COVID-19. It is a prescription that combines Mahaenggamseok-tang, Oryeong-san, Soshiho-tang, Saganmahwang-tang, and Kwakhyangjeonggi-san. According to several clinical reviews, symptoms of COVID-19 were improved, laboratory test indicators were improved, and the cure rate was increased. Pharmacologically, the Qingfei Paidu decoction and its composition have been reported to inhibit viral replication, alleviate immune responses, and have anti-inflammatory and antiviral effects. Severe side effects were not revealed, and this treatment is considered relatively safe. However, to validate and better understand these findings, well-designed clinical studies are needed.