• Title/Summary/Keyword: 과학에 대한 태도

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Hazardous Heavy Metal Contents of Mushrooms from Retail Markets in Seoul (서울 지역에서 유통되는 버섯류의 유해중금속 함량 조사에 관한 연구)

  • Cha, Hyun-A;Kang, Soon-Hwa;Choe, Su-Bin;Kim, Hyung-Kook;Kang, Sung-Tae
    • Korean Journal of Food Science and Technology
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    • v.46 no.3
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    • pp.283-287
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    • 2014
  • This study determined the hazardous heavy metal content of mushrooms from markets in Seoul, Korea. One hundred and fifty mushroom samples were digested by the microwave method then the hazardous heavy metal (Pb, Cd, As, Cr, Ni and Hg) content was determined by the inductively coupled plasma-mass spectrometry (ICP-MS) and mercury analyzer. The average values of heavy metals in the samples were as follows: (mean [minimum-maximum], ${\mu}g/kg$); Pb 7.8 (1.9-30.0), Cd 45.3 (0.7-292.4), As 54.6 (24.2-229.3), Cr 42.6 (8.4-334.3), Ni 22.4 (up to 180.4), and Hg 8.9 (2.0-25.0). The contents of hazardous heavy metal in mushrooms were lower than those reported previously and also lower than the Provisional Tolerable Weekly Intake (PTWI) limit prescribed by the FAO/WHO. Thus, it could be suggested that the hazardous heavy metals levels in the mushrooms of retail market were adequately safe for consumption.

Quality characteristics of sponge cake made with aronia powder (아로니아 분말을 첨가한 스펀지케이크의 품질특성)

  • Jang, Nak Hoon;Roh, Hyeon Su;Kang, Sung Tae
    • Korean Journal of Food Science and Technology
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    • v.50 no.1
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    • pp.69-75
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    • 2018
  • This study was performed to examine the quality characteristics and antioxidant activities of the sponge cakes containing different concentrations (2-10%, w/w) of aronia powder (AP). The specific gravity of the dough and the baking loss rate were significantly increased with higher AP content. The specific volume, height, volume index, and pH were significantly decreased with the increase in AP. The lightness and redness values increased, while the yellowness values decreased with increasing amounts of AP. Textural characteristics, such as hardness, gumminess, and chewiness significantly increased on addition of AP. The DPPH radical scavenging activities of the cakes increased significantly with the increase in concentration of AP. In sensory evaluation, the group with cakes containing AP at 2% concentration was ranked higher than other cakes with respect to all parameters, except for color. Therefore, the results of this study suggest that sponge cakes prepared with 2% AP is the most suitable product, based on its sensory characteristics and antioxidant activities.

Gas Absorption Potential of Oak Charcoal and Modelling for Practical Application (참숯의 가스 흡착능 분석 실험과 실용화 모델링)

  • Park, Youn-Moon;Ha, Hyun-Tae
    • Horticultural Science & Technology
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    • v.19 no.2
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    • pp.174-178
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    • 2001
  • Absorption potential of oak charcoal was estimated using simulated static and dynamic systems to establish a model for practical application of the charcoal in modified atmosphere (MA) packaging and during the storage of 'Fuji' apples. Practical MA packaging was performed using $60{\mu}m$ PE film zipper bags in which five apples were placed. Absorption potential of oak charcoal was $58.4{\mu}L/100g$ charcoal for ethylene and 583 mg/100 g charcoal for carbon dioxide. Effects of enclosing a 100 g-charcoal packet inside a MA package seemed not to last long enough for quality maintenance of 'Fuji' apples stored at $0^{\circ}C$ for three months. During extended storage, ethylene and $CO_2$ levels were not significantly reduced by charcoal treatment. Nevertheless, absorption of carbon dioxide appeared to alleviate the incidence of $CO_2$-related internal browning disorder. Modelling study of practical storage and marketing procedure indicates that 0.19 kg charcoal/day is required to offset $CO_2$ production from 15 kg of apples at $0^{\circ}C$. The amount of charcoal should be increased to 3.10 kg/day if ethylene is a target gas. From the practical point of view, the results suggest that charcoal could be used only for small unit packages for a short period.

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Development and application of improving techniques for watershed water cycle to adapt climate change - Lam Takhong reservoir in Thailand (기후변화 적응 유역 물순환 개선기술 개발 및 적용 - Lam Takhong Reservoir (Thailand))

  • Jang, Cheol Hee;Kim, Hyeon Jun;Cho, Jae Pil
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.395-395
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    • 2018
  • 기후변화 및 토지이용변화에 따라 강우량 및 증발산량 등과 같은 물순환계 구성요소가 변화하면 유역에서의 물순환계가 영향을 받게 된다. 이렇게 변화된 유역의 물순환계를 종합적으로 관리하기 위해서는 물순환 개선 기술을 통한 지속가능하고 건전한 물순환체계의 구축이 필요하다. 유역 물순환 개선 기술은 기후변화가 진행 중에 있거나 예상되는 지역에 대하여 강우-유출수를 지연, 저류, 침투시켜 지속가능한 물순환체계를 유지 회복하도록 하는 기술이라 할 수 있다. 한국건설기술연구원에서는 기후변화 대비 수자원 적응기술 개발 연구단(CCAW, Climate Change Adaptation for Water resources)의 연구비 지원을 받아 유역 건전성 및 취약성을 평가 하고 취약한 유역에 대한 물순환 개선기술을 확보하기 위한 연구를 수행 중에 있다. 특히, 수년간 국가연구개발사업을 통해 개발되고 사업화에 성공한바 있는 유역 물순환 평가 모형인 CAT(Catchment hydrologic cycle Assessment Tool)을 수정 개선하여 수요자 중심의 활발한 현장 적용을 도모하고 있다. 본 연구에서는 개발된 유역 물순환 개선 및 평가시스템의 적용성 평가를 위하여 대상유역으로 태국의 Lam Takhong 저수지 유역을 선정하였다. Lam Takhong 저수지 유역은 유역면적은 $1,423km^2$이며 저류량은 약 $440{\times}106m^3$이다. 입력자료인 DEM, Land Cover 자료는 USGS Hydro1K (https://earthexplorer.usgs.gov/), 하천망 및 유역경계 자료는 USGS HydroSHEDS (https://hydrosheds.cr.usgs.gov/dataavail.php), 기상 및 관측 유입량, 저수지 제원 등의 자료는 APEC 기후센터의 협조를 받아 1976년부터 2016년까지의 일단위 자료를 이용하였다. 모의결과는 저수지 월별 관측 유입량과 상류 유역의 모의 유출량을 이용하여 비교-분석 하였다. Lam Takhong 저수지 상류 유역은 APEC 기후센터에서 SWAT 모형을 이용하여 저수지 유입량 분석을 수행한 바 있다. 따라서 본 연구의 결과를 SWAT 모의결과와 비교하여 그 적용성을 검증하였다. 월별 관측 유입량과 저수지 상류 유역 모의 유출량을 비교한 결과 CAT의 경우 결정계수(R2) 값이 0.86, SWAT은 0.76으로 나타나 CAT의 적용 결과가 좀 더 우수한 것으로 나타났다. 모의 결과는 매개변수 최적화 과정을 거치지 않은 결과이며 SWAT 모형과의 결과 비교를 위하여 매개변수는 동일하게 적용하였다. 향후 매개변수 최적화 모듈을 통해 검 보정 단계를 거친다면 정밀한 분석이 가능할 것으로 판단된다.

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Evaluation of Soil Disturbance Due to Bucket Installation in Sand (모래지반에서 버켓기초 설치에 의한 지반교란 평가)

  • Kim, Jae-Hyun;Lee, Seung-Tae;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.34 no.11
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    • pp.21-31
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    • 2018
  • Bucket foundations are widely used in offshore areas due to their various benefits such as easy and fast installations. A bucket is installed using self-weight and the hydraulic pressure difference across the lid generated by pumping out water from inside the bucket. When buckets are installed in high permeable soil such as sands, upward seepage flow occurs around the bucket tip and interior, leading to a decrease in the effective stress in the soil inside the buckets. This process reduces the penetration resistance of buckets. However, the soil inside and outside the bucket can be disturbed due to the upward seepage flow and this can change the soil properties around the bucket. Moreover, upward seepage flow can create significant soil plug heave, thereby hindering the penetration of the bucket to the target depth. Despite of these problems, soil disturbance and soil plug heave created by suction installation are not well understood. This study aims to investigate the behavior of soil during suction installation. To comprehend the phenomena of soil plug heave during installation, a series of small-scale model tests were conducted with different testing conditions. From a series of tests, the effects of tip thickness of bucket, penetration rate, and self-weight were identified. Finally, soil properties inside the bucket after installation were approximated from the measured soil plug heave.

The effects of antioxidant and anti-aging treatment of UVB-irradiated human HaCaT keratinocytes with ethanol extracts of colored rice varieties (유색미 에탄올 추출물의 산화방지 효과와 UVB에 유도된 인간유래 피부각질형성세포에서의 항노화 효과)

  • Choi, Eun-Young;Lee, Jin-Tae
    • Korean Journal of Food Science and Technology
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    • v.50 no.6
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    • pp.653-659
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    • 2018
  • In this study, we investigated the antioxidant activities and anti-aging efficacy in terms of suppression of matrix metalloproteinases (MMPs) in UVB-irradiated HaCaT cells by adding the ethanol extracts of Josaengheogchal (JE) and Shintoheug rice (SRE). In the electron-donating ability and ABTS radical-scavenging assays, we observed that both JE and SRE had scavenging activities and in a collagenase inhibition assay, both extracts showed inhibition effects of over 73% at $1,000{\mu}g/mL$ concentration. The expression of MMP-1 and -3, when the extracts were treated with UVB $50mJ/cm^2$, irradiated human HaCaT keratinocytes, was analyzed by western blotting and reverse-transcription polymerase chain reaction (RT-PCR). The results showed that MMP-1 and -3 proteins and mRNAs were downregulated in a concentration-dependent manner in response to both extracts. Therefore, we expect that these compounds have a potential for the use as functional ingredients with anti-aging effects in the cosmetic and food industries.

The Antioxidant and Anti-aging Effects of Treatment with Schisandra chinensis Seeds Fractions in UVB-irradiated Human HaCaT Cells (자외선 B에 유도된 사람유래 HaCaT cells에서의 오미자 종자 분획물의 항산화 및 항노화 효과)

  • Choi, Eun-Young;Sohn, Ho-Yong;Lee, Jin-Tae
    • Journal of Life Science
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    • v.29 no.10
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    • pp.1071-1079
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    • 2019
  • In this study, we investigated the antioxidant and anti-aging activities of Schisandra chinensis seed fractions by adding them to UVB-irradiated HaCaT cells and analyzing the suppression of matrix metalloproteinases (MMPs). An electron-donating assay, ABTS radical scavenging assay, and hydrogen peroxide scavenging assay showed that the ethyl acetate fraction of S. chinensis seed (SCEAf) has scavenging activities. A collagenase inhibition activity assay showed that SCEAf had inhibitory effects of over 92.3% at $500{\mu}g/ml$ concentration. An MTT assay was performed to determine the cytotoxicity of SCEAf in HaCaT cells and the results showed that SCEAf increased cellular viability in a concentration-dependent manner. In addition, SCEAf was found to increase the viability of cells irradiatged by UVB $50mJ/cm^2$. To examine the anti-aging effects of SCEAf on HaCaT cells irradiated with UVB $50mJ/cm^2$, the expression of MMP-1 and -3 was analyzed by Western blotting and reverse-transcription polymerase chain reaction. The results showed that MMP-1 and -3 proteins and mRNA levels were downregulated in a concentration-dependent manner in response to SCEAf. These results suggest that SCEAf can prevent aging and alleviate aging symptoms by inhibiting collagenase activity in skin keratinocytes damaged by UVB. Therefore, S. chinensis seeds may have the potential for use as functional ingredients with anti-aging effects in the cosmetic and food industries.

Taxonomic studies of the tribe Potentilleae (Rosaceae) in Korea (한국산 양지꽃족(장미과)의 분류학적 연구)

  • HEO, Kyeong-In;LEE, Sangryong;KIM, Yongsung;PARK, Jongsun;LEE, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.49 no.1
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    • pp.28-69
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    • 2019
  • We conducted taxonomical investigations based on morphological characteristics, fruit morphology, and literature research on the tribe Potentilleae (Rosaceae) in Korea covering seven genera and 24 species. The style position on the ovary and the shape of style were useful characteristics for the classification of subtribal and generic levels in the tribe Potentilleae. The subtribe Fragariinae is characterized by subbasal or lateral style on the ovary and anthers with one theca. The subtribe Potentillinae has a subterminal style on the ovary, except for Argentina, which presents a subterminal and lateral style and anthers with two thecae. These results support the recent taxonomic recognition that i) the tribe Potentilleae consists of two subtribes, and ii) genera such as Dasiphora, Comarum, and Sibbaldianthe sometimes included in Potentilla s.l. are treated as independent genus. In the subtribe Potentillinae, Argentina, which has been treated as Potentilla, is supported as a distinct genus according to the characteristics of the subterminal and lateral style position and the ventral stipular auricles. In Fragaria, F. nipponica subsp. chejuensis, which has generally small leaves and a limited distribution only on Hallasan Mt., is supported by treatment as an endemic species. Duchesnea chrysantha is distinguished from D. indica by the characteristics of light green or yellowish green leaves, thin and somewhat membranous leaflets, and broad ovate or obovate leaflets. Each complex of P. dickinsii and P. chinensis remains unresolved with regard to controversy over the taxonomic circumscription due to their external morphological variations. Additional taxonomical research and molecular population studies are required for a more in-depth understanding of the tribe Potentilleae in Korea.

Evaluation of Whitening Activity and Wrinkle Inhibitory Effect of Ethanol Extracts of Nelumbinis Rhizomatis Nodus (우절 에탄올추출물의 미백활성능과 주름저해 효능평가)

  • Jang, Young-Ah;Yeom, Bo-Seul;Kim, Se-Gie;Lee, Jin-Tae
    • Journal of Life Science
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    • v.29 no.11
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    • pp.1192-1199
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    • 2019
  • The intention of this study was to confirm the possible use of an ethanol extracts of Nelumbinis Rhizomatis Nodus (NRN) as a cosmetic material. To this end, we extracted NRN with 70% ethanol and performed biological activity evaluation of whitening efficacy and wrinkle reduction. We performed cellular tyrosinase inhibition and melanin contents assay to check the whitening activity of NRN and carried out a toxicity evaluation of NRN via an MTT assay and the amounts of associated proteins that affect melanin production in a melanoma cell line (B16F10). And collagenase inhibitory assay was performed for the evaluation of anti-wrinkle of samples. In addition, a toxicity evaluation using an MTT assay and matrix metalloprotease (MMP-1) and procollagen synthesis inhibition by NRN were evaluated in a fibroblast cell line (CCD-986sk). Western blot results for the whitening activity evaluation revealed that the levels of two proteins related to melanin production, tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2), were decreased in a dose-dependent manner. Moreover, collagenase inhibition activity at a concentration of $500{\mu}g/ml$ NRN by measuring epigallocatechin-3-gallate (EGCG) was increased by more than 80% compared to the control group. Meanwhile, procollagen synthesis was reduced by 68.8% in the UVB-induced CCD- 986sk cells group whereas collagen synthesis recovered by 80.2% with $25{\mu}g/ml$ NRN. The MMP-1 expression rate showed 20.2% reduction at $25{\mu}g/ml$. The results of the experiments verified the whitening and wrinkle suppression effects of NRN and confirmed that it could be used as a safe natural cosmetic material in the future.

Analysis of Model of Sport for All Participate Behavior with People with Physical Disabilities Applied to the TPB (계획행동이론을 적용한 지체장애인 생활체육 참여행동 모형 분석)

  • Lee, Hyun-Su
    • 한국체육학회지인문사회과학편
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    • v.51 no.2
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    • pp.431-440
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    • 2012
  • The purpose of this study was to positively examine whether people with physical disabilities participation behavior model of sport for all applying the theory of planned behavior was appropriate for explaining the participation behavior of sport for all and to investigate the effects of causality within the variables. For this study, a questionnaire was designed base on the contents of measuring total five sub variables drawn from Lee Hyun Su's(2011) via an expert conference. Through validity and reliability verification, the final questionnaire was developed. For data analysis, used PASW statistics 18.0, this study conducted Cronbach's α analysis and exploratory analysis to verify the questionnaire's validity and reliability. It also used SEM and CFA as well utilizing AMOS Ver. 7.0. The results of this study were shown below. First, according to the result of verifying the appropriateness of this study model, the model for this study was found to be appropriate since its evaluation indexes for the appropriateness of a model, such as Normed χ2, RMR, IFI, TLI, CFI, and RMSEA, satisfied the criteria for acceptance. Second, there was significantly positive (+) effect of behavioral attitudes on behavioral intention, subjective norms on behavioral intention, perceived behavioral control on behavioral intention, behavioral intention on actual behavior, and perceived behavioral control on actual behavior.