대추와 5개의 균주로 발효시킨 발효대추의 total polyphenol 함량과 in vitro에서의 radical 소거능을 검토한 결과 대추에 비해 발효대추에서의 total polyphenol 함량이 높게 나타났고 DPPH와 ?OH의 소거능이 우수하였으며, 특히 Saccharomyces cerevisiae로 발효시킨 대추가 가장 우수한 효과를 보였다. 이에 대추 추출물과 Sac. cerevisiae로 발효시킨 대추 추출물을 이용하여 C57BL/6N 탈모 마우스실험 모델 하에서 발모 성장 촉진 효과 및 탈모 예방 효과를 검토하였다. 제모 후 EtOH 도포군에서는 거의 발모가 진행되지 않았으나 Zizyphus jujuba(Zj) 도포군과 Sac. cerevisiae-fermented Zj(Zj-Y) 도포군에서는 전체적으로 발모가 진행되었고, 모발의 성장 속도는 minoxidil 도포군>Zj-Y 도포군> Zj 도포군> EtOH 도포군의 순으로 나타났다. 또한 자발적인 탈모에 대한 예방 효과도 대추, 특히 발효대추 도포군에서 우수함을 관찰할 수 있었다. 본 연구 결과로 대추에 비해 발효대추, 특히 Sac. cerevisiae로 발효시킨 대추가 항산화 효능이 뛰어나며, 발모 촉진 효과 및 탈모예방 효과가 우수함을 알 수 있었다.
본 연구는 국내에서 개발 중인 초박층 교면포장용 폴리설파이드 에폭시 폴리머 콘크리트의 물리적 특성을 파악하고 국내로의 적용 가능성을 향상시키기 위해 수행되었다. 바인더와 폴리머 콘크리트의 배합실험을 통해 폴리머 콘크리트의 최적 배합비율을 결정하고, 결정된 배합비율로 생산된 폴리머 콘크리트에 대하여 압축, 휨, 부착 강도 시험을 수행하여 강도특성을 파악하였으며 동결 융해 저항성 시험을 통해 폴리머 콘크리트의 내구성을 평가하였다. 강도 시험 결과, 우수한 강도 성능과 휨 추종성을 나타내었고 미국콘크리트학회에서 제시하는 모든 강도 기준을 충족하였다. 또한 다양한 온도에서의 강도 시험에서도 기존의 재료에 비하여 개선된 성능을 나타내었다. 동결 융해 시험 및 동결 융해 과정을 거친 시편의 강도 시험 결과, 폴리머 콘크리트의 내구성에는 전혀 문제가 없는 것으로 판단된다. 따라서 본 연구에서 새롭게 개발된 폴리머 콘크리트는 초박층 교면포장으로 사용하기에 적절한 특성을 가지고 있을 뿐만 아니라, 온도 민감성도 개선되어 기존의 초박층 교면포장 재료에 비해 폭 넓은 적용성을 갖춘 것으로 판단된다. This research was performed to identify physical properties of polysulfide epoxy polymer concrete for ultra-thin bridge deck pavement, and improve domestic applicability. With the optimum mix ratio determined from mixing experiments of polymer concretes, compressive, flexural, and bond strength were tested to identify its strength properties along with the freezing-thawing resistance test to evaluate its durability in harsh environments. As a result, the tested polymer concretes showed excellent performance in strength and deflection characteristic and all tested strength satisfied the criteria of American Concrete Institute. Moreover, it had better performance under variable temperatures comparing to other existing pavement materials. By the results of freezing-thawing resistance test and strength measurement for specimens underwent the freezing-thawing process, it can be judged that there is no such problem to the concrete's durability. In conclusion, the newly developed polymer concrete in this research has appropriate properties for use in ultra-thin pavement on bridge deck, and moreover it has superior applicability in comparison with former materials due to its improved temperature sensitivity.
Energy and power industrial plants need to improve the health monitoring systems of their facilities, particularly high-risk facilities. This need has created a demand for wireless sensor networks (WSNs). However, for the application of WSN technology in large-scale industrial plants, issues of reliability and security should be fully addressed, and an industrial sensor network standard that mitigatesthe problem of compatibilitywith legacy equipment and systems should be established. To fulfill these requirements, this study proposes a health monitoring system of the pipe-rack structure using ISA100.11a standard. We constructed the system, which consists of field nodes, a network gateway, and a control server, and tested its operation at a large-scale petrochemical plant. The data obtained from WSN-based sensors show that the proposed system can constantly monitor and evaluate the condition of the pipe-rack structure and provide more efficient risk management.
Titanium dioxide (TiO2) nanoparticles were encapsulated with polystyrene (PS)-based copolymeric materials for an electrophoretic display application. This coating process was performed in order to improve the dispersion stability of electrophoretic pigment particles in a dielectric medium and to reduce the density mismatch between TiO2 and the dielectric medium. The characteristics of polymer-coated TiO2 nanoparticles of the density, chemical structure, particle size, shape, and morphology, were examined respectively by FT-IR, thermogravimetric analysis, particle size analysis, and SEM. Additionally, the electrophoretic mobility of the fabricated nanoparticles with a charge control agent was determined by measurements of the zeta potential.
It is of great importance to be able to monitor and enforce vehicle weight limits for road authorities involved in almost all aspects of transportation and pavement engineering. For the active control of additional weight carried by overloaded vehicles, essential IT technologies such as sensors, measurement, and data processing have been applied. The integration of vehicle load monitoring systems with Wireless Sensor Networks (WSN) technology has a possibility of reducing installation efforts and costs, and enabling the quick and easy configuration of data acquisition and control systems. In this paper, we try to verify that WSN technology can replace the wiring sensor applications for vehicle monitoring issues. The WSN-based system includes: inclinometer sensors which measure variation of inclination values with load changes;, an Access Point (AP) that logs the data collected from all these sensors;, and a weight estimation algorithm. To reach the goal, we performed an experiment with real deployment and estimated the weight of trucks with an error of less than 3%. The result shows that it is possible to adopt WSN for commercial vehicle load monitoring.
Titanium dioxide (TiO2) nanoparticles were encapsulated with polystyrene (PS)-based copolymeric materials for an electrophoretic display application. This coating process was performed in order to improve the dispersion stability of electrophoretic pigment particles in a dielectric medium and to reduce the density mismatch between TiO2 and the dielectric medium. The characteristics of polymer-coated TiO2 nanoparticles of the density, chemical structure, particle size, shape, and morphology, were examined respectively by FT-IR, thermogravimetric analysis, particle size analysis, and SEM. Additionally, the electrophoretic mobility of the fabricated nanoparticles with a charge control agent was determined by measurements of the zeta potential.
The purpose of this study is to evaluate the seismic performance of the frame which is assumed to be used with Welded Unreinforced Flange-Bolted web (WUF-B) connections and detailed in compliance with FEMA 350 recommended seismic design criteria. In FEMA 350, these types of connections are only valid for Ordinary Moment-Resisting Steel Frames (OMRSFs). For this purpose, based on test results, we proposed an analytical model for the Post-Northridge WUF-B connections with different panel zone strength ratios. Using the connection model, SAC Phase II three and nine-story frames were modeled and analyzed. From a nonlinear static pushover analysis, ductility, maximum strength, and the maximum interstory drift ratio were investigated for buildings with Post-Northridge details. Moreover, the maximum interstory drift ratio of each performance level (IO and CP) was also investigated through Incremental Dynamic Analysis (IDA). Analytical results were compared with those of buildings with either Pre-Northridge connection or ductile connections with no fracture. The analytical results showed that buildings with Post-Northridge WUF-B connections provide superior strength and interstory drift ratio capacity than buildings with Pre-Northridge WUF-B connections.
Tryptophan synthase alpha-subunit from Escherichia coli functionally exists as a heterotetramer of alpha(2)beta(2) with beta-subunit. While wild-type and mutant (F139W, T24M/F139W, and T24L/F139W) alpha-subunits were expressed as a monomer from recombinant plasmids in Escherichia coli, T24A/F139W, T24S/F139W, and T24K/F139W mutant alpha-subunits were abnormally expressed as soluble homodimers in addition to monomers. Monomers of dimer-forming mutant alpha-subunits retain high affinity to beta-subunit, high activity in stimulating catalytic activities of beta-subunit, and nearly intact content of secondary structure, indicating that the global structures of these monomers are identical to that of F139W alpha-subunit. However, fluorescence spectra of Trp139 and ANS binding indicate that significant perturbations occur in the mutant proteins. Interestingly, these defective properties of monomers caused by residue replacement were partially repaired by the dimer formation. As a result, it is suggested that dimers may be formed by domain or loop swapping, and that residue 24 may play important role in maintaining on-pathway of alpha-subunit folding.