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Wŏnju, South Korea

Lee J.,Nature and Human Co | Kim J.-O.,Rural Research Institute Korea Rural Community Corporation | Owen J.S.,Hankuk University of foreign Studies | Kim B.,Kangwon National University
International Aquatic Research

We evaluated movement of fish, especially Misgurnus spp. (loach), in paddy fields and irrigation ponds by conducting an inventory of δ13C and δ15N of fish, potential food sources, and soil organic matter in two irrigation pond–paddy field systems in Korea. The pond–paddy systems differ with respect to the presence or the absence of a ridge between the paddy field and the irrigation pond and also whether or not livestock are present in their watersheds. The ridge prevents the free movement of fish between paddy field and irrigation pond habitats in one of the pond–paddy watersheds, but not in the other watershed. We found differences in loach δ13C and δ15N inhabiting the paddy fields compared to those in loach δ13C and δ15N in the irrigation ponds. In irrigation ponds, loach δ13C was lower in September (average −27.9 and −27.7 ‰) compared to July (average −26.2 and −26.3 ‰) in the watershed with a ridge (station 1) and without a ridge (station 6), respectively. Loach δ13C in irrigation ponds in September was similar to loach δ13C in the paddy field in July at both sampling sites, indicating loach might have moved into irrigation pond from paddy field. Loach δ15N in the watershed with livestock was significantly higher (average 18.2 ‰) in the irrigation ponds than loach δ15N in the watershed with no livestock present (average 11.3 ‰), probably reflecting higher anthropogenic nitrogen inputs from livestock. Differences in δ13C and δ15N in the loach reflected changes in habitat utilization of loach between paddy fields and irrigation ponds. Aquatic insect δ13C differed from loach δ13C but were more similar to carp δ13C. The stable isotope inventory approach used in this study could be used to augment or replace a more traditional field based mark–recapture approach. © 2015, The Author(s). Source

Jo E.-Y.,Kangwon National University | Cheon J.-L.,Nature and Human Co | Ahn J.-H.,Kangwon National University

The effects of the composition of a mixture containing food waste compost (FWC), rice bran (RB), and oak sawdust (SD) on the antler-type fruiting body (FB) yield of Ganoderma lucidum were studied. Experiments were performed using 0 (control), 5, 10, 15, 20, 25, 30, 35, and 40% (w/w) FWC added to a basal growth medium consisting of 20% (w/w) RB and 80% (w/w) SD. The content of 15% FWC gave the highest FB yield (27.0 ± 1.3 g/bottle),which was 44% higher than the yield (18.6±2.8 g/bottle) of the control treatment. However, FWC contents of 20~40% showed reduced yield (2.4~23.0 g/bottle), partly because FWC had a high Na concentration (0.6%). These results demonstrate the potential for use of FWC as a component of a growth medium for production of G. lucidum FBs. © The Korean Society of Mycology. Source

Lee J.-Y.,Nature and Human Co | Choi J.,Kangwon National University | Owen J.S.,Kyung Hee University | Lee K.,Kangwon National University | And 2 more authors.
Animal Cells and Systems

The aim of this study was to investigate differences in δ13C and δ15N of pond smelt (Hypomesus nipponensis) collected from three brackish lagoons, which have different characteristics, the principal one being the presence or absence of a weir located near the mouth of the outlet channel. The presence or absence of a weir is reflected in a difference in salinity among the study lakes. We found a general pattern of lower pond smelt δ13C values in Lake Mae with lower salinity and higher pond smelt δ13C values in Lake Hwajinpo and Lake Youngrang (lagoons with higher salinity). Pond smelt δ13C values showed little variation among the three lagoons related to pond smelt length, but likely reflected the availability of freshwater prey in Lake Mae. Among the lagoons, we found that pond smelt δ15N values were lower in Lake Hwajinpo compared with pond smelt δ15N values in Lake Youngrang and Lake Mae. This pattern likely shows a difference in anthropogenic nitrogen (N) loading among the lagoons. The results of this study emphasize the utility of stable isotope measurements to better understand how structural characteristics of aquatic ecosystems (presence or absence of a weir) and anthropogenic disturbances can affect stable isotope patterns in aquatic food webs. This stable isotope approach may be a general technique for evaluating fish habitat and restoration or management of coastal lagoon ecosystems. © 2013 Copyright Korean Society for Integrative Biology. Source

Kwon O.-H.,Korea University | Yun H.-K.,Korea University | Han S.-K.,Korea University | Ahn D.-H.,Chungnam National University | And 4 more authors.
Applied Chemistry for Engineering

The main function of conventional insulation materials is only to block the heat transfer and reduce heat loss from the building. On the other hand, thermal storage materials can work as an energy saver by absorbing or emitting heat within a specific temperature range. Thermal storage materials for building can maintain a constant temperature by effectively regulating the cycle of indoor temperature. As a result, we can enhance the performance of a cooling and heating system efficiently. In this study, phase change materials (PCMs) were added as thermal storage materials into gypsum boards which are extensively used for building material and we found out the thermal environmental characteristics. In addition, we checked out some problems when applying the thermal storage materials to buildings. Finally, This study set out to examine the degree of environmental-friendly characteristics of thermal storage building materials by analyzing the amount of TVOC and HCHO contents with the possibility of pollutants emission. Source

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