Background: The biological activities of Tradescantia pallida grown in Korea have not been well determined, thus the aim of this study was to investigate the possibility of using it as a medicinal plant. Methods and Results: To investigate the antioxidant activity, α-glucosidase inhibitory effect and antimicrobial activity of T. pallida, we performed the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. This assay for T. pallida leaf extract showed the highest antioxidant activity for the ethyl acetate fraction (RC50= 14.55 ± 0.16㎍/㎖ and Abs = 0.613 at 300㎍). Further, the ethyl acetate fraction exhibited higher α-glucosidase inhibitory effect with an IC50 value of 14.1 ± 0.1㎍/㎖ and showed antimicrobial activity against gram positive bacteria (minimum inhibitory concentration = 1,000㎍/㎖). Conclusions: The ethyl acetate fraction of the crude methanol extract of T. pallida showed remarkable antioxidant activity, α-glucosidase inhibitory effects and antimicrobial activity. These activities might be related to the flavonoid content in the T. pallida leaf extract.

Improvement of winter hardiness, lodging resistance and good quality have been recently received more attention by covered barley(Hordeum vulgare L.) breeders than ever in Korea. ‘Hyeyang’, a new covered barley cultivar with early maturing and high yield was developed by the National Institute of Crop Science, RDA in 2010. It was derived from the cross between‘Milyang87’and‘Wolsung8120’with good quality. The initial cross was done in 1999 and the selected line, ‘Iksan432’ (YB4494-B-B-21-2), showed high yield and good quality characteristics under yield trial test from 2008 to 2010. The following is the characteristics of‘Hyeyang’that is characterized as the vernalization of Ⅰ, green leaf, compact spike and long rough awns. The heading date of‘Hyeyang’were similar to‘Olbori’. The culm length was 82 cm which was 6 cm shorter than‘Olbori’. It showed the spike length of 4.3 cm, 798 spikes / m2, 56 grains / spike and 26.7 g for 1,000 grains weight. It showed similar winter hardiness and stronger resistance to barley yellow mosaic virus (BaYMV) compare to‘Olbori’. It showed higher diastatic power 235DP than that of check cultivar, ‘Olbori’. Average yield of ‘Hyeyang’ was 4.44 MT/ha in the regional yield trials carried out in four location at double cropping system in Korea from 2008 to 2010, which was 8 percent higher than ‘Olbori’. ‘Hyeyang’would be suitable for the area above –8℃ of daily minimum temperature in January in Korean peninsula.

본 연구는 해상풍력발전기에 추가적인 통신전용선로를 확보하지 않고도 자체 전력선을 이용하여 나셀의 상태를 감시할 수 있는 시스템을 구현하는 것을 목표로 한다. MW 급 해상풍력발전기의 내부 전력선을 훼손하지 않고도 통신선로를 확보하기 위하여 유도성 결합기 기반 비접촉식 무배선 통신시스템을 제안하고 성능시험 결과를 보고한다. 페라이트 복합물질을 이용하여 최대 500 A의 고 전류에도 동작할 수 있는 전력선 통신용 유도성 결합기를 개발하였으며 제주도 풍력단지에서 실증시험을 진행하였다. iperf를 이용한 통신성능시험에서 풍력발 전기 나셀부와 하단 기저부의 전력변환기간 100 m 길이의 전력선으로 최소 15 Mbps 이상의 통신 속도를 안정적으로 확보할 수 있음을 보였 다. 이를 바탕으로 1 주일간의 연속적인 통신상태 시험을 수행하였으며 평균 20 Mbps의 데이터 전송률을 확인하였다. 시험기간 동안 단한번 의 통신 불량도 발생하지 않았다. 다음으로 나셀 내부 온도 분포와 변화를 측정하기 위하여 적외선 카메라를 설치하였다. 카메라에서 획득한 실시간 열화상 이미지가 오류 없이 성공적으로 전송됨을 확인하였다.

In this study, we compared disease incidence rate and phyllosphere microbial community between drought resistance transgenic rice (Agb0103) and non-transgenic Ilmi (NGM) during 2011-2014 to examine an environmental risk assessment of drought resistance transgenic rice (Agb0103). As the results, major diseases such as sheath blight, brown spot, leaf blast and false smut were occurred, however, there were no significant disease incidence rate between Agb0103 and NGM. As the results of counting bacterial and fungal viable cell, the colonies were increased or decreased which affected by environmental conditions, however there were no differences between Agb0103 and NGM. Also unweighted pair-group method with arithmetic averaging (UPGMA) analysis based on polymerase chain reaction with denaturing gel electrophoresis (PCR-DGGE) revealed that DGGE band pattern of bacterial and fungal communities were clustered by each month and there were no differences between Agb0103 and NGM. Furthermore, isolated casual agents causing sheath blight and brown spot were collected from Agb0103 and NGM, and they revealed that each of pathogens were no differences in morphology and pathogenicity. Therefore, our results suggested that Agb0103 showed no differences in disease incidence rate, characteristic of pathogens and phyllosphere community with NGM. In this way, it can be assumed that transgenic rice Agb0103 could not influence phyllosphere microorganism community and environmental conditions.

The preaent study was conducted to investigate the effect of mixed seeding of three wheat variwties, ‘Anzunbaengimil’, ‘Jokyoung’, and ‘Sooan’, on agricultural characteristics and quality of plants to select the most suitable mixed seeding ratio. We observed that the yield of plants obtained from the mixed seeding combinations was higher than those obtained from single seeding of the three varieties. The yield was high, especially for the combinations ‘Sooan’ and ‘Anzunbaengimil’ (80 and 20%, respectively) and ‘Sooan’ and ‘Jokyoung’ (90 and 10%, respectively). The protein content of the seedlings obtained from the above two combinations was higher than in the seedling of ‘Sooan’. Based on our results, we suggest that mixed seeding of wheat varieties is more effective than single seeding in improving the yield and quality of plants obtained from mixed seeding.

Anther culture is useful and significant tool for producing haploid or doubled haploid (DH) plants in crop breeding system. Androgenesis is the way of inducing haploid and DH plants from anther (immature pollen) or microspore culture. In vitro androgenesis is efficient technique for introducing complete homozygous lines in one generation, thus less time and expense could be necessary than conventional plant breeding. In maize, anther culture is important system for shortening the breeding cycle and enhancing selection efficiency. Anther culture technique is also applicable to various researches such as molecular genetics, genetic engineering, genomics, and plant biotechnology. We review the past and present studies on anther culture and provide useful information for future researches on androgenesis in maize. The combination of androgenesis with other techniques such as molecular breeding and biotechnology is producing a variety of variety of maize species. In addition, we suggest strategy to develop androgenesis technique adapted to Korean research environment.

The thermal and mechanical properties of fiber-reinforced cement-based composite for solar thermal energy storage were investigated in this paper. The effect of the addition of different cement-based materials to Ordinary Portland cement on the thermal and mechanical characteristics of fiber-reinforced composite was investigated. Experiments were performed to measure mechanical properties including compressive strength before and after thermal cycling and split tensile strength, and to measure thermal properties including thermal conductivity and specific heat. Test results showed that the residual compressive strength of mixtures with OPC and slag was greatest among cement-based composite. Thermal conductivity of mixtures including graphite was greater than that of any other mixtures, indicating favor of graphite for improving thermal transfer in terms of charging and discharging in thermal energy storage system. The addition of CSA or zirconium increased specific heat of fiber-reinforced cement-based composite. Test results of this study could be actually used for the design of thermal energy storage system in concentrating solar power plants.

이 논문의 목적은 압축강도 130 MPa급의 고강도 강섬유 보강 콘크리트 보의 휨거동 특성을 파악하는데 있다. 부피비 1.0%의 강섬 유와 철근비 0.02 이하의 철근으로 보강된 고강도 강섬유 보강 콘크리트의 휨거동 특성 실험결과를 제시하였다. 일반강도철근과 고강도철근 을 실험 부재에 사용하였다. 강섬유 보강 콘크리트의 압축 및 인장거동 재료 실험과 모델링을 수행하였다. 강섬유 보강 콘크리트의 하중-균열 개구변위 실험결과를 반영하여 가상균열모델에 근거한 역해석을 통해 인장거동모델링을 제시하였다. 실험결과는 강섬유 보강 콘크리트와 고 강도철근의 사용은 균열제어 및 연성 거동에 유리한 것을 나타낸다. 일반강도철근을 사용한 보의 휨강도 실험값에 대한 수치해석에 의한 예측 값의 비는 0.81~1.42를 나타내고, 고강도철근을 사용한 보의 휨강도 실험값에 대한 수치해석에 의한 예측값의 비는 0.92~1.07을 나타낸다. 수 치해석에 의한 휨강도는 실험결과를 합리적으로 예측하고 있는 것으로 판단된다.

With the development of nanotechnology, nanomaterials are used in various fields. Therefore, the interest regarding the safety of nanomaterial use is increasing and much effort is diverted toward establishment of exposure assessment and management methods. Occupational exposure limits (OELs) are effectively used to protect the health of workers in various industrial workplaces. This study aimed to propose an OEL for domestic multi-walled carbon nanotubes (MWCNTs) based on animal inhalation toxicity test. Basic procedure for development of OELs was examined. For OEL estimation, epidemiological study and quantitative risk assessment are generally performed based on toxicity data. In addition, inhalation toxicity data-based no observed adverse effect level (NOAEL) and benchmark dose (BMD) are estimated to obtain the OEL. Three different estimation processes (NEDO in Japan, NIOSH in USA, and Baytubes in Germany) of OELs for carbon nanotubes (CNTs) were intensively reviewed. From the rat inhalation toxicity test for MWCNTs manufactured in Korea, a NOAEL of 0.98 mg/㎥ was derived. Using the simple equation for estimation of OEL suggested by NEDO, the OEL of 142 μg/㎥ was estimated for the MWCNT manufacturing workplace. Here, we used test rat and Korean human data and adopted 36 as an uncertainty factor. The OEL for MWCNT estimated in this work is higher than those (2-80 μg/㎥) suggested by previous investigators. It may be greatly caused by different physicochemical properties of MWCNT and their dispersion method and test rat data. For setting of regulatory OELs in CNT workplaces, further epidemiological studies in addition to animal studies are needed. More advanced technical methods such as CNT dispersion in air and liquid should be also developed.

This study was carried out to investigate the flora of Mt. Baegam (1,099 m) from March, 2014 to July, 2015. The vascular plants were summarized as 506 taxa, including 90 families, 293 genera, 435 species, 5 subspecies, 58 varieties and 8 forms. Among the investigated 506 taxa, 14 Korean endemic, 16 rare plants and 80 specially designated plants (Ⅴ degree: 3 taxa, Ⅳ degree: 7 taxa, Ⅲ degree: 22 taxa, Ⅱdegree: 21 taxa, Ⅰ degree: 27 taxa) by the Ministry of Environment were also included. The naturalized plants were 36 taxa including 3 ecosystem disturbance wild plant. The urbanization index and percent of naturalized plants species were estimated as 11.2% and 7.1%, respectively. Useful plants of 506 taxa listed consists of 207 taxa (40.9%) of edible plants, 200 taxa (39.5%) of pasture plants, 146 taxa (28.9%) of medicinal plants, 58 taxa (11.5%) of ornamental plants and 15 taxa (3.0%) of timber plants, respectively.