최근 세계적으로 신재생에너지에 대한 관심이 커지고 있으며, 국내의 경우 폐바이오매스를 이용하는 친환경적인 에너지원으로써 활용할 수 있는 연료화 기술이 각광받고 있다. 국내 폐바이오매스는 크게 식품폐기물, 축산폐기물, 농산부산물, 임산부산물 및 하수슬러지 등으로 구분할 수 있으며, 이를 에너지원으로 전환하는 공정은 생물학적, 열화학적 공정으로 크게 구분할 수 있다. 국내 하수슬러지의 경우, 해양투기가 금지된 이후 에너지로 전환하여 재활용하기 위한 연구가 활발히 진행되고 있으며, 2014년 환경부에 따르면 전국 하수슬러지 처리시설은 98개 지자체에서 96개의 하수슬러지 처리시설이 운영되고 있고, 추가적으로 18개의 시설이 설계 및 건설되고 있다. 이 중 대부분의 시설은 고화 및 건조연료화를 통해 하수슬러지 처리량 저감을 하고 있으나, 고화 및 건조 연료화를 통한 하수슬러지 저감은 슬러지 자체의 높은 수분함량으로 인해 상대적으로 많은 에너지를 필요로 한다. 본 연구는 하수슬러지의 연료화를 위해 열화학적 공정 중 하나인 반탄화 공정을 이용하여 10 TPD급 폐바이오매스 반탄화 반응 시스템을 구성하였다. 원료물질인 하수슬러지의 높은 수분함량에 따른 열량 부족 문제를 극복하기 위해 폐목재를 혼합하여 사용하였으며, 반응온도(250-350℃)와 하수슬러지와 폐목재 혼합물의 혼합비(6:4, 4:6)에 대하여 운전 조건의 최적화 연구를 수행하였으며, 결과적으로 반탄화물 수율 70% 이상, 생성된 탄화물의 고위발열량 4,000 kcal/kg 이상의 운전조건을 도출할 수 있었다. 이와 더불어 생산된 반탄화물의 원소분석에 따른 C, H, O의 구성비는 저품위 석탄과 유사하게 나타남을 확인할 수 있었다.
The objective of this study was to estimate air quality trends in the study area by surveying monthly and seasonal concentration trends. To do this, the mass concentration of PM10 samples and the metals, ions, and total carbon in the PM10 were analyzed. The mean concentration of PM10 was 33.9 ㎍/㎥. The composition of PM10 was 39.2% ionic species, 5.1% metallic species, and 26.6% carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the PM10 and had a high correlation coefficient with PM10. Seasonal variation of PM10 showed a similar pattern to those of ionic and metallic species. with high concentration during the winter and spring seasons. PM10 showed high correlation with the ionic species NO3 - and NH4 +. In addition, NH4 + was highly correlated with SO4 2- and NO3 -. We obtained four factors through factor analysis and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor accounted for 51.1% of PM10 from complex sources, that is, soil, motor vehicles, and secondary particles: the second factor indicated marine sources; the third factor, industry-related sources; and the last factor, heating-related sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea because it was from US EPA. Therefore, to more accurately estimate the pollutants present, it is necessary to create a pollution profile for Korea.
Nitrogen budgets in Sihwa-ho in 2010 were estimated using a mass balance approach. Major nitrogen fluxes sources can be divided into three sections: cities, agricultural area, and forest. Surplus nitrogen 2,030~2,214 ton/yr (2,123 ton/yr in average) was discharged to Sihwa Lake. 20% of the surplus nitrogen is removed from the wetland and 60% is removed tidal flats. Therefore net nitrogen discharge from Sihwa basin is estimated to be 650 708 ton/yr (679 ton/yr in average). Wet and dry nitrogen deposition and load from non-point sources ware estimated to be 97 ton/yr and 69 ton/yr, deposition is using CAMx model. So estimated total nitrogen discharge into Sihwa-ho was 817 875 ton/yr (846 ton/yr in average). The atmospheric load explains 11.1 11.9% (11.5% in average) of the total nitrogen load Sihwa-ho.
This paper describes a study on posture control of the multi-legged biomimetic underwater robot (CALEB10). Because the underwater environment has a feature that all degrees of freedom are coupled to each other, we designed the posture control algorithm by separating each degree of freedom. Not only should the research on posture control of underwater robots be a precedent study for position control, but it is also necessary to compensate disturbance in each direction. In the research on the yaw directional posture control, we made the drag force generated by the stroke of the left leg and the right leg occur asymmetrically, in order that a rotational moment is generated along the yaw direction. In the composite swimming controller in which the controllers in each direction are combined, we designed the algorithm to determine the control weights in each direction according to the error angle along the yaw direction. The performance of the proposed posture control method is verified by a dynamical simulator and underwater experiments.
Purpose – The purpose of this study is to examine the image similarity and attribute recognition of the top 10 rated spa destinations (Chungnam Deoksan, Chungnam Dogo, Busan Dongrae, Daejeon Yuseong, Chungnam Asan, Gyeongbuk Bomun, Chungbuk Suanbo, Gyeongnam Jangyu, Chungnam Onyang, & Gyeongbol Bugok) in Korea based on the visits to these spa places by the customers.
Research design, data, and methodology – The survey of this study was conducted on the visitors to the top 10 spa destinations in Korea from April 8 ∼ April 21, 2017, and a total of 300 questionnaires were distributed. Of them, effective questionnaires used in the final study were a total of 241. In this study, empirical analysis was made through frequency analysis, factor analysis, and multidimensional scaling ALSCAL(spinning symmetry for image similarity and rectangle for attributes recognition) by using the Statistics Package SPSS 24.0.
Results – According to the analysis result of spa destination image similarity, the stress level was 0.16453 and the level of the stress was good. Moreover, the coefficient of determination (RSQ) was, which had a description of each aspect of the spa destination, 0.79908. According to the results of attribute recognition, the stress value of 0.11805 represents a degree of conformity, and the coefficient of determination(RSQ) appeared at 0.98665. Therefore, the results of this analysis are that the similarities between spa destinations and the attribute recognition of the spa destinations is a suitable model that is properly expressed in two dimensions.
Conclusions – First, according to the analysis result of image similarity, Deoksan & Dogo spa revealed similar images, as well as the Dongrae and Yuseong spa, while on the contrary Asan, Bomun, Suanbo spa has different images from the rest. Second, according to the results of attribute recognition, Asan and Onyang spa has competitiveness in terms of accessibility to spa destination; Yuseong, Dongrae, Jangyu spa in terms of spa facilities, spa tourism conditions, and service & shopping conditions. while spa water quality and spa costs showed low attribute reflection for all 10 spas. Therefore, the spa visitors cannot recognize the differentiation of spa water quality and spa costs.
In order to investigate the PM10 concentration trend and its characteristics over five different sub area in Busan from 2013 to 2015, data analysis with considering air flow distribution according to its topography was carried out using statistical methodology. The annual mean concentrations of PM10 in Busan tend to decrease from 49.6㎍/m³ in 2013 to 46.9㎍/m³ in 2015. The monthly mean concentrations value of PM10 were high during spring season, from March to May, and low during summer and fall due to frequent rain events. The concentration of PM10 was the highest in five different sub-area in Busan. High concentration episodes over 90 percentile of daily PM10 concentration were strongly associated with mean daily wind speed, and often occurred when the westerly wind or southwesterly wind were dominant. Regardless of wind direction, the highest correlation of PM10 concentrations was observed between eastern and southern regions, which were geographically close to each other, and the lowest in the western and eastern regions blocked by mountains. Wind flow along the complex terrain in Busan is also one of the predominant factors to understand the temporal variation of PM10 concentrations.
This study identified physical characteristics and aerosol particle sources of PM10 and PM2.5 in the industrial complex of Busan Metropolitan City, Korea. Samples of PM10, PM2.5 and also soil, were collected in several areas during the year of 2012 to investigate elemental composition. A URG cyclone sampler was used for collection. The samples were collected according to each experimental condition, and the analysis method of SEM-EDX was used to determine the concentration of each metallic element. The comparative analysis indicated that their mass concentration ranged from 1% to 3%. The elements in the industrial region that were above 10% were Si, Al, Fe, and Ca. Those below 5% were Na, Mg, and S. The remaining elements (1% of total mass) consisted of elements such as Ni, Co, Br and Pb. Finally, a statistical tool was applied to the elemental results to identify each source for the industrial region. From a principal components analysis (SPSS, Ver 20.0) performed to analyze the possible sources of PM10 in the industrial region, five main factors were determined. Factor 1 (Si, Al), which accounted for 15.8% of the total variance, was mostly affected by soil and dust from manufacturing facilities nearby, Factors 2 (Cu, Ni), 3 (Zn, Pb), and 4 (Mn, Fe), which also accounted for some of variance, were mainly related to iron, non-ferrous metals, and other industrial manufacturing sources. Also, five factors determined to access possible sources of PM2.5, Factor 1 (Na, S), accounted for 13.5% of the total variance and was affected by sea-salt particles and fuel incineration sources, and Factors 2 (Ti, Mn), 3 (Pb, Cl), 4 (K, Al) also explained significant proportions of the variance. Theses factors mean that the PM2.5 emission sources may be considered as sources of incineration, and metals, and non-ferrous manufacturing industries.
본 연구에서는 약콩(Glycine soja Siebold et Zucc.) 분획 추출물의 미백효능을 관찰하기 위해 B16F10 멜라노마 세포에서 TRP-1 (tyrosinase related protein-1), TRP-2 (tyrosinase related protein-2), 티로 시나제 발현을 평가하였다. 그 결과 약콩 분획 추출물 0.125, 0.25, 0.5, 2.0 mg/mL 농도에서 82% 이상의 높 은 세포생존율을 나타내었다. α-melanocyte stimulating hormone (α-MSH)을 처리한 B16F10 멜라노마 세포에 약콩의 EtOAc 분획 추출물을 처리한 결과 티로시나제 발현이 감소되었으며 TRP-1, TRP-2 단백질 발현이 감소하였다. 이러한 결과는 약콩 분획 추출물이 멜라닌생합성과 관련되는 단백질의 발현을 감소시켜 피 부 미백효능을 나타내는 것으로 기대할 수 있다.
A new Phalaenopsis cultivar SM 6310 was bred by Kyungpook National University, Korea. The new cultivar SM 6310, showing the phenotype of yellow colored mini type characteristics, was introduced by artificial crossing of Phalaenopsis ‘Brother Gold Miss’ and Phalaenopsis philippinensis. An elite individual number ‘03-06-31’ later named as ‘SM 6310’ was selected among 250 individual progenies for more than 2 years(2004-2005) intensive selection process covering excellent vegetative and flowering characteristics. In year 2006-2007, the 1st and 2nd characteristic analysis were performed through stability and uniformity test. The ‘SM 6310’ shows that flower color is bright clean yellow (RHS#:12B) and flower shape is small type with size of 5.8 and 6.1cm in flower length and width, respectively. ‘SM 6310’ is regarded as raceme flower type suitable small flower pot market. The leaf of ‘SM 6310’ is rowing horizontally and about 15.6cm in length and 7.1cm in width. This cultivar also possesses no genetic variation, fast invitro propagation and easy growing due to vigorous growth habit. This ‘SM 6310’ is registered (Reg.#:3825) to Korea Seed & Variety Service (KSVS) in 21 December, 2011 and PBR (plant breeder's right) is currently controlled by Sangmiwon Orchid Company, Korea.
Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by global agricultural companies. Until now, GM crops have not been cultivated commercially in Korea. Commercialization of GM crops requires a compulsory assessment of environmental risk associated with the release of GM crops. This study was conducted to evaluate the frequency of pollen mediated gene flow from Bt transgenic rice (Agb0101) to japonica non-GM rice (Nakdongbyeo), indica non-GM rice (IR36), and weedy rice (R55). A total of 729,917, 596,318 and 230,635 seeds were collected from Nakdongbyeo, IR36, and R55, respectively, which were planted around Agb0101. Selection of the hybrids was determined by repeated spraying of herbicide and Cry1Ac1 immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using specific primer. The hybrids were found in all non-GM rice and out-crossing ranged from 0.0005% at IR36 to 0.0027% at Nakdongbyeo. All of hybrids were located within 1.2 m distance from the Agb0101 rice plot. The meteorological elements including rainfall and temperature during rice flowering time were found to be important factors to determine rice out-crossing rate. Consideration should be taken for many factors like the meteorological elements of field and physiological condition of crop to set up the safety management guideline to prevention of GM crops gene flow.
As a result of evaluating the spalling properties using a restrained ring-type concrete specimen, in the case of rapid heating, the water vapor pressure rapidly rise and the surface spalling is repeated. In the case of low-speed heating, The water vapor pressure accumulated in the concrete exceeded the limit, and explosive spalling occurred inside.
This study was conducted to determine correlations and similarity between the ozone and PM10 data of 19 air quality monitoring stations in Busan from 2013 to 2016, using correlation and cluster analyses. Ozone concentrations ranged from 0.0278±0.0148 ppm at Gwangbok to 0.0378±0.017 ppm at Taejongdae and were high in suburban areas, such as Yongsuri and Gijang, as well as in coastal areas, such as Jaw, Gwangan, Taejongdae and Noksan. PM10 concentrations ranged from 37.2±25.0 ug/m3 at Gijang to 58.3±32.2 ug/m3 at and Jangrim. PM10 concentrations were high in the west, exceeding the annual ambient air quality standard of 50 ug/m3. Positive correlations were observed for ozone at most stations, ranging from 0.61 between Taejongdae and Sujeong to 0.92 between Bugok and Myeongjang. The correlation coefficients of PM10 between stations ranged from 0.62 between Jangrim and Jaw to 0.9 between Gwangbok and Sujeong. Yeonsan, Daeyeon, and Myeongjang were highly correlated with other stations, so they needed to be reviewed for redundancy. Ozone monitoring stations were initially divided into two sections, north-western areas and suburban-coastal areas. The suburban-coastal areas were subsequently divided into three sections. PM10 monitoring stations were initially divided into western and remaining areas, and then the remaining areas were subsequently divided into three sections.
We retrieved rotational temperatures from emission lines of the OH airglow (8-3) band in the sky spectra of the Sloan digital sky survey (SDSS) for the period 2000-2014, as part of the astronomical observation project conducted at the Apache Point observatory (32°N, 105°W). The SDSS temperatures show a typical seasonal variation of mesospheric temperature: low in summer and high in winter. We find that the temperatures respond to solar activity by as much as 1.2 K ±0.8 K per 100 solar flux units, which is consistent with other studies in mid-latitude regions. After the seasonal variation and solar response were subtracted, the SDSS temperature is fairly constant over the 15 year period, unlike cooling trends suggested by some studies. This temperature analysis using SDSS spectra is a unique contribution to the global monitoring of climate change because the SDSS project was established for astronomical purposes and is independent from climate studies. The SDSS temperatures are also compared with mesospheric temperatures measured by the microwave limb sounder (MLS) instrument on board the Aura satellite and the differences are discussed.
The CALEB10 is a multi-legged biomimetic underwater robot. In the last research, we developed a swimming pattern named ESPG (Extended Swimming Pattern Generator) by observing diving beetle’s swimming actions and experimented with a positive buoyancy state in which CALEB10 floats on the water. In this paper, however, we have experimented with CALEB10 in a neutral buoyancy state where it is completely immersed in water for pitch motion control experiment. And we found that CALEB10 was unstably swimming in the pitch direction in the neutral buoyancy state and analyzed that the reason was due to the weight proportion of the legs. In this paper, we propose a pitch motion control method to mimic the pitch motion of diving beetles and to solve the problem of CALEB10 unstably swimming in the pitch direction. To control the pitch motion, we use the method of controlling additional joints while swimming with the ESPG. The method of obtaining propulsive force by the motion of the leg has a problem of giving propulsive force in the reverse direction when swimming in the surge direction, but this new control method has an advantage that a propulsive moment generated by a swimming action only on a target pitch value. To demonstrate validity this new control method, we designed a dynamics-based simulator environment. And the control performance to the target pitch value was verified through simulation and underwater experiments.
This study was conducted to investigate how PM10 concentration and Relative Humidity (RH) affected visibility in Jinju, Korea. A 9-yr dataset of 1 h averages for visibility, PM10, and RH data was analyzed to examine the correlation between these variables. On average, visibility decreased by 1.4 km for every 10 μg/㎥ increase in PM10 and by 2.1 km for every 10% increase in RH. In general, a negative correlation was observed between visibility and and PM10 concentration. However, under conditions of low PM10 concentration(< 15 μg/㎥) and visibility(< 2 km), there was a positive correlation between these two variables. In this case, RH levels were high (> 75%). A high correlation analysis between two variables need to be under control conditions with RH < 75%, PM10 15~100 μg/㎥, and visibility > 2 km.
The F2-layer critical frequency (foF2) data from several ionosondes are employed to study the long-distance effect of the M8.8 Chile Earthquake of February 27, 2010, on the F2 layer. Significant perturbations of the peak F2-layer electron density have been observed following the earthquake at two South African stations, Hermanus and Madimbo, which are located at great circle distances of ~8,000 and ~10,000 km from the earthquake epicenter, respectively. Simplified estimates demonstrate that the observed ionospheric perturbations can be caused by a long-period acoustic gravity wave produced in the F-region by the earthquake.