• 소성∙가공
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• 제28권3호
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• pp.123-129
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• 2019

Hypereutectic Al-Si alloys have been widely utilized for wear-resistant components in the automotive industry. In order to expand the application of Hypereutectic Al-Si alloys, the addition of alloying elements forming a stable precipitate at high temperature is required. Thermally stable inter metallic compounds can be formed through the addition of transition elements such as Fe, Ni to Al alloys. However, the amount of transition element to be added to Al alloys is limited due to their low solid solubility. Also, hypereutectic Al-Si-Fe alloys form coarse primary Si phases and needle-shaped intermetallic compounds during solidification in the general casting processes. In this study, the effects of the destruction of Intermetallic compound and Si phase are investigated via hot extrusion. Both the microstructure and mechanical properties are discussed under different extrusion conditions.

• Journal of the Korean Wood Science and Technology
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• 제47권2호
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• pp.178-188
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• 2019

Licorice, which has an extensive history of use as an herbal medicine, has been suggested to have oral health benefits. However, to date, no systematic study has been conducted on the preparation method of licorice extracts for oral health. In this study, licorice extracts prepared using water and ethanol were investigated for its ability to inhibit the biofilm formation of Streptococcus mutans. The licorice extract prepared with around 60% ethanol effectively inhibited the biofilm formation of S. mutans. Licorice extracted with 50% ethanol almost completely inhibited the biofilm formation at 1.5 g/L of licorice extract. This inhibitory activity was confirmed in a microplate assay and a flow cell system. Glycyrrhetic acid was extracted from licorice effectively with 60% ethanol concentration. The strong inhibitory activity of glycyrrhetic acid and the synergistic inhibition with glycyrrhizin on biofilm formation were suggested as major reasons for a concentration-specific extraction. These results suggest that licorice extract prepared using around 60% ethanol effectively inhibits the biofilm formation of S. mutans.

• 전자통신동향분석
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• 제34권4호
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• pp.76-88
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• 2019

With advances in olfactory sensor technologies, the number of reports on various intelligent applications using multiple sensors (sensor arrays) are continuously increasing for fields such as medicine, environment, security, etc. For intelligent and point-of-care applications, it is not only important for the sensor technology to perform chemical or physical measurements rapidly and accurately, but it is also important for artificial intelligence technology to recognize and quantify specific chemicals or diagnose diseases such as lung cancer and diabetes. In particular, great advances in pattern recognition technologies, including deep learning algorithms, as well as sensor array technologies, are expected to enhance the potential of various types of olfactory intelligence applications, including early cancer diagnosis, drug seeking, military operations, and air pollution monitoring.

• Steel and Composite Structures
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• 제33권2호
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• pp.299-306
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• 2019

The natural fibre composites are termed as bio-composites. They have shown a promising replacement to the current carbon/glass fibre reinforced composites as environmental friendly materials in specific applications. Natural fibre reinforced composites are potential materials for various engineering applications in automobile, railways, building and Aerospace industry. The natural fibre selected to fabricate the composite material is plant-based fibre e.g., sisal fibre. Sisal fibre is a suitable reinforcement for use in composites on account of its low density, high specific strength, and high hardness. Epoxy is a thermosetting polymer which is used as a resin in natural fibre reinforced composites. Hand lay-up technique was used to fabricate the composites by reinforcing sisal fibres into the epoxy matrix. Composites were prepared with the unidirectional alignment of sisal fibres. Test specimens with different fibre orientations were prepared. The fabricated composites were tested for mechanical properties. Impact test, tensile test, flexural test, hardness test, compression test, and thermal test of composites had been conducted to assess its suitability in industrial applications. Scanning electron microscopy (SEM) test revealed the microstructural information of the fractured surface of composites.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.372-372
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• 2019

본 논문에서는 격자 기반의 2차원 침수해석 모형인 G2D(Grid based 2-Dimensional land surface flood model)의 GUI 개발에 대해서 기술하였다. G2D 모형은 ASCII 래스터 포맷의 DEM을 이용하여 정형 사각격자로 구성되는 침수모의 도메인을 설정하고, 수위, 수심, 유량 등의 경계조건과 강우와 유량을 연속방정식의 생성항으로 사용하여 2차원 침수모의를 한다. 주요한 침수모의 결과는 ASCII 래스터 포맷을 가지는 수심과 수위 등이다. 이와 같이 G2D 모형은 ASCII 래스터 파일을 주로 이용하고 있다. 본 연구에서는 우선 래스터 파일의 전후처리와 침수모의 결과의 가시화에 대한 편의성을 높이기 위해서 GIS 소프트웨어를 이용하여 GUI를 개발하고자 하였다. 이와 더불어 사용자들이 소프트웨어 구매 비용에 대한 부담을 없애고, 편리하게 사용할 수 있는 오픈소스 소프트웨어를 이용하고자 하였으며, 이 두 가지 조건을 만족할 수 있는 QGIS를 이용해서 G2D 모형의 GUI인 QGIS-G2D를 개발하였다. QGIS-G2D는 QGIS의 plug-in으로 실행된다. QGIS-G2D는 G2D 모형의 실행에 필요한 프로젝트 파일(.g2p)을 GUI를 이용해서 만들 수 있으며, 모의결과를 애니매이션 등으로 가시화 할 수 있는 후처리 기능을 포함하고 있다. 또한 QGIS-G2D는 DEM 수정 기능과 같이 G2D 모형의 입력자료 전처리를 위해서 QGIS plug-in으로 제공되는 여러 가지 기능을 함께 이용할 수 있다. 또한 물리적 분포형 강우-유출 모형인 GRM(Grid based Rainfall-runoff Model)의 QGIS plug-in인 QGIS-GRM과 연계하여, 유역 유출모의와 침수모의를 QGIS 환경에서 함께 수행할 수도 있다. 개발된 소프트웨어는 오픈소스 플랫폼인 GitHub(https://github.com/floodmodel/)를 통해서 제공된다. 본 연구를 통해서 홍수해석에 필요한 강우-유출 모의와 침수모의를 위한 모형을 제공하고, 이를 편리하게 활용할 수 있는 오픈소스 소프트웨어를 제공할 수 있었다. 이러한 연구들은 홍수 분야의 전문가들에 의해서 다양한 분야의 홍수해석에 사용될 수 있을 것으로 기대한다.

• 동서간호학연구지
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• 제26권1호
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• pp.1-16
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• 2020

Purpose: The purpose of this study was to evaluate the effectiveness of non-pharmacologic interventions for chronic nonspecific low back pain (CLBP) in adults aged 18-64 years. Methods: We searched for potentially relevant randomized controlled trials and non-randomized controlled trials through five Korean electronic databases (i.e., Korean Studies Information Service System, Research Information Sharing Service, Korean Medical Database, KoreaMed, and National Assembly Library) published from January 2010 to May 2019. Two investigators independently selected the studies based on the criteria and assessed risk of bias in the included studies. We estimated the effect size of interventions using Comprehensive Meta Analysis 3.3. Results: Of 10,151 studies, 26 studies met the inclusion criteria and 15 studies were included in the meta-analysis. Exercise reduced low back pain (Hedges's g=-1.53, 95% CI: -2.22 to -0.85) and pain-related disabilities (Hedges's g=-0.92, 95% CI: -1.40 to -0.45). We found that taping was effective in decreasing low back pain (Hedges's g=-1.12, 95% CI: -1.51 to -0.73) and pain-related disabilities (Hedges's g=-0.50, 95% CI: -0.93 to -0.07). Manual therapy yielded a marginally significant reduction in low back pain (Hedges's g=-2.32, 95% CI: -4.64 to 0.00), the therapy was not effective in decreasing pain-related disabilities. Conclusion: Although there was little evidence for the effectiveness of manual therapy in adults with CLBP, exercise and taping were effective to relieve pain and pain-related disabilities. Based on these findings, we suggest the development of non-pharmacologic interventions or a nursing intervention protocol for the CLBP management. Also, nurses should consider implementation of effective non-pharmacologic interventions for CLBP.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.700-707
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• 2020

This study is concerned with the investigation of the half-space albedo problem for "İnönü-linear-quadratic anisotropic scattering" by the usage of Modified FN method. The method is based on Case's method. Therefore, Case's eigenfunctions and its orthogonality properties are derived for anisotropic scattering of interest. Albedo values are calculated for various linear, quadratic and İnönü anisotropic scattering coefficients and tabulated in Tables.

• 소성∙가공
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• 제28권5호
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• pp.294-310
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• 2019

• Journal of Plant Biotechnology
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• 제46권3호
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• pp.189-204
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• 2019

본 연구의 목적은 유묘기 TO1000DH3와 Early big에서 MeJA 처리에 의해 글루코시놀레이트 함량 변화 및 유전자의 발현 변화를 분석하기 위하여 수행되었다. $200{\mu}M$ 농도의 MeJA를 처리하여 글루코시놀레이트 함량을 분석한 결과, 글루코시놀레이트 총 함량이 처리 전보다 TO1000DH3에서 1.3~1.5배, Early big에서 1.3 ~ 3.8배 증가하였다. 알리패틱 글루코시놀레이트인 progoitrin과 gluconapin은 TO1000DH3에서만 검출되었으며, neoglucobrassicin 성분의 함량 변화가 MeJA 처리 48시간 후 TO1000DH3와 Early big에서 가장 크게 증가되었다. 전사체 분석을 통해 TO1000DH3에서는 stress나 defense 반응에 관여하거나, 생장과 관련된 전사체가 특이적으로 발현하고, Early big에서는 nucleoside 또는 ATP 생합성 관련 전사체가 특이적으로 발현하는 것을 알 수 있었다. MeJA를 처리함에 따라 발현이 2배 이상 변한 전사체를 TO1000DH3에서 12,020개, Early big에서 13,510개를 선발하여 GO 분석한 결과 stimulus, chemical에 반응하는 전사체의 발현이 공통적으로 증가하였고, single-organism 및 ribosome 합성 관련 전사체의 발현이 공통적으로 감소하였다. 특히 glucobrassicin, neoglucobrassicin 함량과 연관되어 발현이 증가한 인돌릭 글루코시놀레이트 생합성 관련 전사체의 발현이 모두 증가하였다 (MYB34 (Bo7g098110), IGMT2 (Bo8g070650), CYP81D1 (Bo6g056440), CYP81D4 (Bo7g118500), CYP81F4 (Bo1g004730, Bo01007s020), CYP81G1 (Bo4g154660), CYP83B1 (Bo8g024390) 및 CYP91A2 (Bo1g003710)). 글루코시놀레이트 생합성 경로 관련 유전자를 대표하는 전사체 104개를 선발하여 발현 양상을 분석한 결과 transcription factor에 속하는 MYB28, MYB51의 발현은 MeJA 처리 전에 비해 처리 후 발현양이 감소하였지만, 대부분의 전사체의 발현은 MeJA 처리에 의해 증가하였다. MeJA 처리에 의해 AOP3 (Bo9g006220, Bo9g006240), TGG1 (Bo14804s010)는 TO1000DH3에서만 특이적으로 발현이 증가하였고, Dof1.1 (Bo5g008360), UGT74C1 (Bo4g177540), GSL-OH (Bo4g173560, Bo4g173550, Bo4g173530)는 Early big 특이적으로 발현이 증가하였다. MeJA 처리 전 두 계통에서 발현이 가장 높은 글루코시놀레이트 생합성 관련 유전자는 GSTU20이었고, MeJA 처리에 의해 12시간 후TO1000DH3에서 CYP79B2 (Bo7g118840), Early big에서는 CYP79B3 (Bo4g149550)의 발현이 가장 많이 증가하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제21권4호
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• pp.9-12
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• 2019

We performed Raman spectroscopy on two different over-doped Bi₂Sr₂CaCu₂O_8+x (BSCCO), of which superconducting transition temperatures are 89 K and 77 K. Line-shape analysis of the Raman-spectrum was done, focused on B_1g bond buckling mode which have drawn a lot of attention, since photoemission studies showed an evidence for strong coupling between the mode and electron. The line-shapes show asymmetry and are well fitted by the Fano line-shape formula. Remarkably, we found that the peak line-widths from B_1g bond buckling mode in BSCCO show much broader than those in YBa₂Cu₃O_7-x. The broad line width can be attributed to the superstructure modulation of BSCCO. Our results imply that B_1g bond buckling mode may have close relation to the origin of superconductivity or to boosting the superconducting transition temperature in BSCCO.