ZnO micro/nanocrystals with different morphologies were synthesized by thermal evaporation of various zinc source materials in an air atmosphere. Zinc acetate, zinc carbonate and zinc iodide were used as the source materials. No catalysts or substrates were used in the synthesis of the ZnO crystals. The scanning electron microscope(SEM) image showed that the morphology of ZnO crystals was strongly dependent on the source materials, which suggests that source material is one of the key factors in controlling the morphology of the obtained ZnO crystals. Tetrapods, nanogranular shaped crystals, spherical particles and crayon-shaped crystals were obtained using different source materials. The X-ray diffraction(XRD) pattern revealed that the all the ZnO crystals had hexagonal wurtzite crystalline structures. An ultraviolet emission was observed in the cathodoluminescence spectrum of the ZnO crystals prepared via thermal evaporation of Zn powder. However, a strong green emission centered at around 500 nm was observed in the cathodoluminescence spectra of the ZnO crystals prepared using zinc salts as the source materials.

Yi, So Young. 2017. “Social and stylistic variation in vowel raising in Seoul Korean”. The Sociolinguistic Journal of Korea 25(3). 165~197. The purpose of this study is to examine extralinguistic factors that influence vowel raising of /o/ in constituent-final -ko and -to in Seoul Korean, focusing mainly on the influence of social variations and stylistic variations on this phenomenon. The Sociolinguistic interview data showed that older speakers used the most raised variant of /o/ in the AP-medial position, which is evidence for age-grading for the following reasons: (i) the linguistic marketplace, which is an important concept in age-grading, supports this idea because older people use the non-standard form of /o/, which is the raised variant, after they leave the workforce, and (ii) the unraised variant does not push out the raised variant, but rather, they co-exist. In addition, stylistic variations related to the formality of the speech setting and the solidarity between interactants affect the vowel, leading to vowel raising (i) in casual speech situation and (ii) in interaction with an addressee with whom the speaker is intimate; these trends are especially salient for younger speakers.

Skin barrier function can be assessed non-invasively, including by transepidermal water loss (TEWL), skin hydration, and sebum level. The aim of this study was to evaluate day-to-day variation in measurements of TEWL, skin hydration, and sebum level at various anatomic sites and the relationship between these parameters in normal dogs. Measurements were repeated five times on two separate days in five clinically normal Beagle dogs at seven anatomic sites, i.e., the left and right pinnae, left and right axillae, left and right groin areas, and ventrum. Coefficient of variation was used to show the variation in measurements. Correlations between each of the measurements were analyzed to determine the contribution of skin hydration and sebum level to TEWL. There was no variation in the measurements obtained according to time or anatomic site (P>.0.05). The coefficient of variation was highest for sebum level (209.0 ± 81.8%) followed in descending order by skin hydration (62.7 ± 34.5%) and TEWL (41.1 ± 6.9%). Of the seven anatomic sites sampled, the left and right pinnae showed the lowest variation in repeated measurements for TEWL (39.2%), skin hydration (29.6%), and sebum level (75.5%). There was no significant relationship between the results for each measurement (P>.0.05). Because of its relatively low variation on repeated measurement, TEWL might be the most useful way of evaluating skin condition in dogs.

Colletotrichum acutatum J. H. Simmonds is an important fungal pathogen that causes anthracnose disease in crops. In this study, 59 C. acutatum isolates from regions in South Korea were collected and phenotypically compared. The average colony diameters of isolates from Gyeongsangbuk-do, Chungcheongbuk-do, and Gangwon-do were 4.36 cm, 4.24 cm, and 4.38 cm, respectively, following 6 days of growth on V8 juice agar. The average conidium concentrations of the isolates from each province were 14.43, 12.83, and 10.17 × 104/mL after 7 days of growth on V8A. Amplified fragment length polymorphism(AFLP) analysis using three primer pairs identified 5 polymorphic bands and 56 monomorphic bands. Two polymorphic bands were identified using the E-ACC/M-CTT primer pair, one polymorphic band was identified using the E-ACG/M-CTG primer pair, and two polymorphic bands were identified using the E-ACG/M-CTT primer pair. A dendrogram was constructed using the AFLP data, and four clusters were identified.

This experiment was performed to analyze the annual variation of growth traits of soybean to determine the information of less sensitive traits and stable cultivars based on the environmental conditions. Sowing was carried out on June 2 for each year and the test plot was arranged in three replicates by randomized complete block design with thirty soybean varieties including two landraces during the period 2014-2015. The weather conditions during the test period were quite different with extremely low precipitation and longer sunshine duration in 2015. The variation of characteristics related to growth period such as days of growth, days of maturity, days of flowering and 100-seed weight were less in spite of different environmental conditions. While the variation of the number of pods per plant was high. Considering growth and seed characteristics like the number of pods per plant, the number of seeds per pod, and 100-seed weight which are linked directly to the yield, cultivars such as Shingi, Daewonkong, Danbaegkong, and Daepung for beancurd and soypaste, Pungwon, Haepum and Shingang for soy-sprout and Seoritae for cooking with rice were more stable and are expected to have high yield in Suwon, the south-central part of South Korea. These results are useful for the selection of breeding resources to develop cultivars with high stability under changeable weather condition.

We investigate the solar cycle variation of microwave and extreme ultraviolet (EUV) intensity in latitude to compare microwave polar brightening (MPB) with the EUV polar coronal hole (CH). For this study, we used the full-sun images observed in 17 GHz of the Nobeyama Radioheliograph from 1992 July to 2016 November and in two EUV channels of the Atmospheric Imaging Assembly (AIA) 193 A° and 171 A° on the Solar Dynamics Observatory (SDO) from 2011 January to 2016 November. As a result, we found that the polar intensity in EUV is anti-correlated with the polar intensity in microwave. Since the depression of EUV intensity in the pole is mostly owing to the CH appearance and continuation there, the anti-correlation in the intensity implies the intimate association between the polar CH and the MPB. Considering the report of Gopalswamy et al. (1999) that the enhanced microwave brightness in the CH is seen above the enhanced photospheric magnetic field, we suggest that the pole area during the solar minimum has a stronger magnetic field than the quiet sun level and such a strong field in the pole results in the formation of the polar CH. The emission mechanism of the MPB and the physical link with the polar CH are not still fully understood. It is necessary to investigate the MPB using high resolution microwave imaging data, which can be obtained by the high performance large-array radio observatories such as the ALMA project.

The well-known solar cycle controls almost the entire appearance of the solar photosphere. We therefore presume that the continuous emission of visible light from the solar surface follows the solar cyclic variation. In this study, we examine the solar cyclic variation of photospheric brightness in the visible range using solar images taken by the Solar and Heliospheric Observatory (SOHO)/Michelson Doppler Imager (MDI). The photospheric brightness in the visible range is quantified via the relative intensity acquired from in the raw solar images. In contrast to total solar irradiance, the relative intensity is out of phase with the solar cycle. During the solar minimum of solar cycles 23--24, the relative intensity shows enhanced heliolatitudinal asymmetry due to a positive asymmetry of the sunspot number. This result can be explained by the strength of the solar magnetic field that controls the strength of convection, implying that the emission in the visible range is controlled by the strength of convection. This agrees with the photospheric brightness increasing during a period of long spotless days.

In this study, a winch and load motion control system design method is introduced. Especially, the winch and load (moving cart) are connected with long wire rope which is extended to few kilometers long. Therefore, the rope length changes such that many dynamic parameter values are changed as well by winding and releasing the rope from the winch system. In this paper, the authors designed the control system by considering the real time parameter variation to occupy and keep good control performance continuously. The effectiveness of introduced method was evaluated by simulation results.

CO2농도와 온도의 상승으로 인한 지구온난화가 진행되었을 때 광, 수분 그리고 유기물 구배에 따른 멸종위기식물인 황근의 생육과 생태적 지위폭의 변화를 알아보았다. 대조구(야외)와 처리구(CO2 + 온도 상승구)로 나누어 각각 광, 수분 그리고 유기물구배를 두어 재배하였다. 그 연구결과, 황근은 낮은 광량보다 높은 광량을 선호하나, 광량이 787±77.76μmol m-2s-1을 넘어가면 높은 광량이라 하더라도 생육이 어려웠다. 또한 유기물이 없거나(0%) 너무 많은 토양(20%)에서는 생육이 어려웠다. 그러나 수분 구배에 따른 경향이 보이지 않았다. 황근의 고사율은 대조구보다 처리구에서 광량이 높은 조건을 제외한 모든 구배에서 높았다. 이는 CO2와 온도가 상승하면 광에 대한 내성범위가 좁아진다는 것을 의미한다. 대조구와 처리구를 비교하였을 때, 수분구배에 따른 경향은 보이지 않았다. 유기물구배에서 는 대조구보다 처리구에서 모두 고사율이 낮았는데, 이는 유기물에 대한 내성의 범위가 넓어진 것을 의미한다. 황근의 생태적 지위폭은 처리구가 대조구보다 광 구배에서 30.1% 좁아졌으며, 수분 구배에서 8.6% 그리고 유기물 구배에서 30% 넓어졌다. 따라서 CO2농도와 온도의 증가로 인한 지구온난화가 진행되면, 황근의 생육은 광량에 의해서 제한될 것으로 판단된다.

From June 2007 to May 2008, seasonal variations of bacterial abundance and heterotrophic nanoflagellate (HNF), together with environmental factors, were investigated at weekly and monthly intervals in Kyeonggi Bay. During the study period, the water temperature and salinity varied from 1.9℃~29.0℃ and 31~35.1 psu, respectively. The concentration of ammonia, nitrate+nitrite, phosphate, and silicate ranged from 0.01 to 3.22 μM, 2.03 to 15.34 μM, 0.06 to 1.82 μM, and 0.03 to 18.3 μM, respectively. The annual average concentration of Chl. a varied from 0.86 μg L-1 to 37.70 μg L-1; the concentration was twice as much at the surface than at the deeper layers. The abundance of bacteria and HNF ranged from 0.29×106 to 7.62×106 cells mL-1 and 1.00×102 to 1.26×103 cells mL-1, respectively. In particular, there were significant correlations between bacteria and HNF abundance (p<0.05), and then the high abundance of HNF was frequently observed with an increase of bacterial abundance in summer (p<0.001). Our results therefore indicate that bacterial abundance in the bay was mainly controlled by resources supplied as organic and inorganic substances from Lake Shihwa due to the daily water exchange after dike construction. Also, the bacterial abundance was significantly controlled by HNF grazing pressure (top-down) in the warm seasons, i.e. excluding winter, in the Kyeonggi Bay.

The number of children who use day-care centers is increasing. Most indoor air quality (IAQ) management has been based on daily average pollutant concentrations measured once a year. A more comprehensive management of IAQ is needed to protect children’s health from air pollutants in day-care centers. In this study, we investigated the weekly variation of air pollutant concentrations in a nursing room of a day-care center located at the roadside for a week in June of 2014. Average concentrations of CO2, PM10, black carbon, and total surface area of lungdeposited particles during nursing time of the day-care center were 510 ppm, 27.8 μg/m3, 1.87 μg/m3, and 30.6 μm2/cm3, respectively, with a similar diurnal pattern shown on weekdays.

To improve the efficiency of hairtail trolling, it is important to gain an accurate understanding of the distribution of fish based on their diurnal vertical migration patterns. This study evaluated the vertical distribution of hairtails through catch efficiency tests using vertical longlines. Five replicate tests of the efficiency were carried out on the eastern coast of Jeju Island from August to September 2016, from 11:00 AM to 03:00 PM in the daytime and 11:00 PM to 03:00 AM in the nighttime. The fishing gear was composed of 20 hooks per line set, numbered in order from the first hook near the surface to the last hook on the seabed. The depth of the first hook was 18 m, and that of the last hook was 86 m. Pacific saury was used as the baits. In total, 10 sets of fishing gear were used per trip. After fishing, we counted the hairtails at each numbered hook, which were summed up both by number and in aggregate. A total of 232 hairtails were caught using 2,000 hooks: 193 individuals at daytime and 39 at nighttime. The hook rate was 11.5% : 9.6% at daytime; 2.0% at nighttime. For both daytime and nighttime catches, there were variations in the hook rates at each numbered hook. In the daytime, a maximum of 28.5% catches occurred at hook number 18, followed by 21.4% at number 20, and 10.7% at number 17, accounting for 60.6% of the daytime hook rates. In the nighttime, a maximum of 23.0% catches occurred at hook number 1, followed by 15.3% at hook number 4 and 9, accounting for 53.6% of the nighttime hook rate. Based on the above results, hairtails are usually distributed in deeper region in daytime, whereas they occur near the surface in nighttime. Therefore, it is necessary to position trolling lines according to diurnal vertical distribution layers of hairtails for fishing efficiency.