The growth characteristics of Paeonia ostii ‘Fengdan’ seedlings roots in response to trichokonins-spray treatment were investigated in this study. One-year-old seedlings of P. ostii ‘Fengdan’ were potted in plastic cups containing garden mold and grown under field conditions. The results showed that application of trichokonins significantly promoted root growth in P. ostii ‘Fengdan’ seedlings. The total root projection area, total root surface area, total root volume, total root length, root number and root diameter of seedlings treated with 0.25 mg/L trichokonins were higher by 141.70, 116.59, 119.44, 55.97, 348.88 and 127.78%, respectively, than that of the control. Thus, the results supported the hypothesis that good growth condition for roots could directly improve their nutrient absorption and utilization efficiency, promoting plant growth and development.
The heat budget is investigated in the Gumi Reservoir of the Nakdong river. In warm climate season, solar radiation effects play a important role in the change of water temperature. The features of the surface heat balance are almost derived by the latent heat flux and the solar radiation flux. On the other hand, in cold climate season, change of heat stored in the water is mainly dominated by latent and sensible heat transfer between water and air, since flux of solar radiation and loss of outgoing long wave radiation balance approximately. For the annual averages, net flux of radiation, evaporation(latent heat) loss are dominant in the Gumi reservoir. The evaporation losses are dominant from spring to early winter. This means that the Gumi reservoir rolls like a lake of thermal medium or deep depth.
This study analyzes the PM10 characteristics (particulate matter with aerodynamic diameter less than 10 ㎛), concentration, and emissions in eight large South Korean cities (Seoul, Incheon, Daejeon, Daegu, Gwangju, Ulsan, Busan, Jeju). The annual median of PM10 concentration showed a decline of 0.02~1.97 ㎍/㎥ in the regions, except for Incheon, which recorded an annual 0.02 ㎍/㎥ increase. The monthly distribution levels were high in spring, winter, fall, and the summer, but were lower in summer for all regions except for Ulsan. These differences are thought to be due to the dust in spring and the cleaning effect of precipitation in summer. The variation in concentrations during the day (diurnal variation) showed that PM10 levels were very high during the rush hour and that this was most extreme in the cities (10.00 and 18.00-21.00). The total annual PM10 emissions analysis suggested that there had been a general decrease, except for Jeju. On-road mobile (OM) sources, which contributed a large proportion of the particulates in most regions, decreased, but fugitive dust (FD) sources increased in the remaining regions, except for Daegu. The correlation analysis between PM10 concentrations and emissions showed that FD could be used as a valid, positive predictor of PM10 emissions in Seoul (74.5% (p<0.05)), Dajeon (47.2% (p<0.05)), and Busan (59.1% (p<0.01)). Furthermore, industrial combustion (IC) was also a significant predictor in Incheon (61.7% (p<0.01)), and on-road mobile (OC) sources were a valid predictor in Daegu (24.8% (p<0.05)).
The present study was investigated the effect of recycled coir organic substrates on the growth of different vegetable crops. The recycled coir had better physical and chemical properties than the new coir. The growth of tomato plant was better on the coir substrate that had been used for 2 years than that on the new coir substrate. The average number of tomato fruits was 108 on the new coir substrate, while it was 179 and 165 on the coir substrate used for 1 and 2 years, respectively. The growth of cherry tomato plant was also better on the coir substrate used for 2 years than that on the new coir substrate. The average number of cherry tomato fruits was 43 on the new coir substrate, while it was 206 and 164 on the coir substrate used for 1 and 2 years, respectively. The growth of brussel sprout was better on the coir substrate used for 3 years than that on the new coir substrate and the average number of brussel sprout leaves was 26.8 on the new coir substrate, while it was 34.3 on the coir substrate used for 3 years. The growth of Korean cabbage improved on the coir substrate used for 1 years compared to the new coir substrate and the number of leaves was 15.1 on the new coir substrate, while it was 24.3 on the coir substrate used for 1 year. Thus, used coir can be recycled to improve vegetable yields compared to using new coirs.
The concepts of residence time and flushing time can be used to explain the exchange and transport of water or materials in a coastal sea. The application of these transport time scales are widespread in biological, hydrological, and geochemical studies. The water quality of the system crucially depends on the residence time and flushing time of a particle in the system. In this study, the residence and flushing time in Gamak Bay were calculated using the numerical model, EFDC, which includes a particle tracking module. The average residence time was 55 days in the inner bay, and the flushing time for Gamak Bay was about 44.8 days, according to the simulation. This means that it takes about 2 months for land and aquaculture generated particles to be transported out of Gamak Bay, which can lead to substances accumulating in the bay. These results show the relationships between the transport time scale and physical the properties of the embayment. The findings of this study will improves understanding of the water and material transport processes in Gamak Bay and will be important when assessing the potential impact of coastal development on water quality conditions.
The present study was performed to investigate the psychological effects of spring flowers blossoms, which is one of the elements influencing to human psychology, in order to provide scientific evidence on the psychological benefits of green plants. A self-reporting survey was conducted by using self reporting questionnaires on the impression (semantic differential method: SD method) and mood states (profile of mood states: POMS) of eighty university students in their twenties. Korean forsythia, Korean rosebay, Japanese apricot, Cherry blossom, and Magnolia were chosen as spring flowers. The results of impression evaluation and mood states changes showed that spring flower blossom had beautiful, soft, warm, moist, familiar and full impressions, and changed our mood positively by reducing depression and anger, or by increasing vigor. In addition, different psychological effects can be differently observed depending on the species; for example, Cherry blossom had a greater effect in changing the impression and feeling than others. The findings would provide support toward the active usage in green space as well as its design maximizing the psychological effects of nature.
This research, sponsored by the Korean Ministry of Environment in 2014, was the first epidemiological study in Korea that investigated the health impact assessment of radon exposure. Its purpose was to construct a model that calculated the annual mean cumulative radon exposure concentrations, so that reliable conclusions could be drawn from environment-control group research. Radon causes chronic lung cancer. Therefore, the long-term measurement of radon exposure concentration, over one year, is needed in order to develop a health impact assessment for radon. Hence, based on the seasonal correction model suggested by Pinel et al.(1995), a predictive model of annual mean radon concentration was developed using the year-long seasonal measurement data from the National Institute of Environmental Research, the Korea Institute of Nuclear Safety, the Hanyang University Outdoor Radon Concentration Observatory, and the results from a 3-month (one season) survey, which is the official test method for radon measurement designated by the Korean Ministry of Environment. In addition, a model for evaluating the effective annual dose for radon was developed, using dosimetric methods. The model took into account the predictive model for annual mean radon concentrations and the activity characteristics of the residents
To analyze human thermal environments in protected horticultural houses (plastic houses), human thermal sensations estimated using measured microclimatic data (air temperature, humidity, wind speed, and solar and terrestrial radiation) were compared between an outdoor area and two indoor plastic houses, a polyethylene (PE) house and a polycarbonate (PC) house. Measurements were carried out during the daytime in autumn, a transient season that exhibits human thermal environments ranging from neutral to very hot. The mean air temperature and absolute humidity of the houses were 14.6-16.8℃ (max. 22. 3℃) and 7.0-12.0 g∙m-3 higher than those of the outdoor area, respectively. Solar (K) and terrestrial (L) radiation were compared directionally from the sky hemisphere (↓) and the ground hemisphere (↑). The mean K↓ and K↑ values for the houses were respectively 232.5-367.8 W∙m-2 and 44.9-55.7 W∙m-2 lower than those in the outdoor area; the mean L↓ and L↑ values were respectively 150.4-182.3 W∙m-2 and 30.5-33.9 W∙m-2 higher than those in the outdoor area. Thus, L was revealed to be more influential on the greenhouse effect in the houses than K. Consequently, mean radiant temperature in the houses was higher than the outdoor area during the daytime from 10:45 to 14:15. As a result, mean human thermal sensation values in the PMV, PET, and UTCI of the houses were respectively 3.2-3.4℃ (max. 4.7℃), 15.2-16.4℃ (max. 23.7℃) and 13.6-15.4℃ (max. 22.3℃) higher than those in the outdoor area. The heat stress levels that were influenced by human thermal sensation were much higher in the houses (between hot and very hot) than in the outdoor (between neutral and warm). Further, the microclimatic component that most affected the human thermal sensation in the houses was air temperature that was primarily influenced by L↓. Therefore, workers in the plastic houses could experience strong heat stresses, equal to hot or higher, when air temperature rose over 22℃ on clear autumn days.
This study was conducted to compare the antioxidant, anticytotoxic, and anti-inflammatory properties of Euphorbia maculata ethanol extract with those of E. supina ethanol extract. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide scavenging activities of E. maculata at 50 μg/mL were 38.3 ± 3.7 and 21.5 ± 1.2%, respectively, whereas those of E. supina at the same concentration were 109.4 ± 0.9 and 59.5 ± 4.8%, respectively. Oxygen radical absorbance capacities of E. maculata and E. supina at 10 μg/mL were 14.70 ± 0.63 and 26.17 ± 1.36 nmol/mL Trolox, respectively. Cupric reducing antioxidant capacities of E. maculata and E. supina at 10 μg/mL were 10.22 ± 0.97 and 62.99 ± 5.28 nmol/mL Trolox, respectively. Total phenolic contents of E. maculata and E. supina at 50 μg/mL were 29.03 ± 0.14 and 87.89 ± 0.20 nmol/mL gallic acid, respectively. E. maculata and E. supina were reported to prevent supercoiled DNA breakage induced by peroxyl and hydroxyl radicals in a concentration-dependent manner, where protection against the supercoiled DNA breakage provided by E. supina was greater than that provided by E. maculata. E. maculata and E. supina at 100 μg/mL inhibited tert-butyl hydroperoxide-induced cytotoxicity in HepG2 cells by 49.4 ± 4.3 and 87.3 ± 4.5%, respectively. E. maculata and E. supina at 500 μg/mL inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells by 63.1 ± 7.0 and 85.2 ± 1.6%, respectively. The antioxidant capacities including DPPH radical scavenging, superoxide scavenging, oxygen radical absorbance, and cupric reducing antioxidant activity were found to be highly correlated with total phenolic content (0.896 < r < 0.983, p < 0.01) and anticytotoxic activities (0.915 < r < 0.960, p < 0.01). However, the superoxide scavenging activity was not significantly correlated (r = 0.604, p > 0.05) with the anti-inflammatory activity. Thus, these findings demonstrated that the radical scavenging, anticytotoxic, and anti-inflammatory capacities of E. supina were more potent than those of E. maculata. Further studies are needed to elucidate the properties of polyphenolic constituents in E. supina responsible for these effects and the underlying mechanisms.
Plant biomass, photosystem II (PSII) photochemical activity, photosynthetic function, and zinc (Zn) accumulation were investigated in a sorghum-sudangrass hybrid (Sorghum bicolor × S. sudanense) exposed to various Zn concentrations to determine the elimination capacity of Zn from soils. Plant growth and biomass of the sorghum-sudangrass hybrid decreased with increasing Zn concentration. Symptoms of Zn toxicity, i.e., withering and discoloration of old leaves, were found at Zn concentrations over 800 ppm. PSII photochemical activity, as indicated by the values of Fv/Fm and Fv/Fo, decreased significantly three days after exposure to Zn concentrations of 800 ppm or more. Photosynthetic CO2 fixation rate (A) was high between Zn concentrations of 100-200 ppm (22.5 μmol CO2・m –2・s –1), but it declined as Zn concentration increased. At Zn concentrations of 800 and 1600 ppm, A was 14.1 and 1.8 μmol CO2・m –2・s –1, respectively. The patterns of stomatal conductance (gs), transpiration rate (E), and water use efficiency (WUE) were all similar to that of photosynthetic CO2 fixation rate, except for dark respiration (Rd), which showed an opposite pattern. Zn was accumulated in both above- and below-ground parts of plants, but was more in the below-ground parts. Magnesium (Mg) and iron (Fe) concentrations were significantly low in the leaves of plants, and symptoms of Mg or Fe deficiency, such as a decrease in the SPAD value, were found when plants were treated with Zn concentrations above 800 ppm. These results suggest that the sorghum-sudangrass hybrid is able to accumulate Zn to high level in plant body and eliminate it with its rapid growth and high biomass yield.
The treatment efficiencies of domestic sewage treatment processes were analysed and assessed to suggest and design a suitable technology for coal seam gas (CSG) water treatment. Two sewage treatment plants (S and G in Busan) were selected. The former operates with standard activated sludge and modified Ludzak Ettinger processes while the later uses the combination of A2/O and gravity fiber filtration. For both plants, the concentrations of BOD, CODMn, T-N and T-P were about 5.0, 19.0, 5.0, 11.0 and 1.0 ppm, respectively, which satisfy the discharge standards. Therefore, although sewage treatment processes seems to be applicable for CSG water treatment, additional processes to remove total dissolved solids and ionic compounds (i.e. bicarbonate) need to be introduced to produce fit-for-purpose water resources for beneficial use (in accordance with Water ACT 2013). This, for the CSG treatment process design, it is necessary to align the operating conditions with merging methods of combinable unit technology obtained from sewage treatment processes.
The accuracy of digital elevation models (DEMs) is crucial for properly estimating flood inundation area. DEM pixel size is especially important when generating flood inundation maps of small streams with a channel width of less than 50 m. In Korea, DEMs with large spatial resolutions of 30 m have been widely applied to generate flood inundation maps, even for small streams. Additionally, when making river master plans, field observations of stream cross-sections, as well as reference points in the middle of the river, have not previously been used to enhance the DEM. In this study, it was graphically demonstrated that high-resolution DEMs can increase the accuracy of flood inundation mapping, especially for small streams. Also, a methodology was proposed to modify the existing low-resolution DEMs by adding additional survey reference points, including river cross-sections, and interpolating them into a high spatial resolution DEM using the inverse distance weighting method. For verification purposes, the modified DEM was applied to Han stream on Jeju Island. The modified DEM showed much better accuracy when describing morphological features near the stream. Moreover, the flood inundation maps were formulated with the original 30 m pixel DEM and the modified 0.1 m pixel DEM using HEC-RAS modeling of the actual flood event of Typhoon Nari, and then compared with the flood history map of Nari. The results clearly indicated that the modified DEM generated a similar inundation area, but a very poor estimate of inundation area was derived from the original low-resolution DEM.
In order to prepare the information needed to construct a reduction system for volatile organic compounds (VOCs) exhausted from ship-block paint-booths in a giant shipyard, VOCs in paint-shop airs were analyzed and compared to the components in paint thinners. Aromatic hydrocarbons containing eight and nine carbon atoms are known to be major VOC compounds found in shipyard paint-shops. The total hydrocarbon (THC(C7)) concentrations calibrated using toluene gas, were measured in block paint-shops with two photo-ionization detector (PID) meters, and the resulting THC(C7) data were converted to THC(C1) concentrations according to the Standard Methods for the Measurements of Air Pollution in South Korea. THC(C1) concentrations near the spray site ranged from 10 to 2,000 ppm, but they were less than 400 ppm near the walls of the paint-booth. The measurements of THC concentrations, based on the height of the monitoring sites, were related to the height of the target to which the spray paints were applied. The maximum concentrations occurred at almost the same height as the spray targets. When painted blocks had been dried-by warming with no spraying, the THC concentrations were 80~100 ppm.
Transported deposit was accumulated in a grit chamber built at the mouth of Yeocheoncheon in 1987 with the intention of blocking the influx of sediment into the Ulsan-harbor. This study attempted to analyze the effects of the transported deposit on the water quality at Yeocheoncheon. Only one episode of dredging has been performed in the approximately 25 years since the grit chamber were built, leading to the formation of stagnant water in the grit chamber due to a large amount of transported deposit. The deposit has a relatively high organic content, in the range of 11.7-25.9% (mean 18.3%). It appears that the main reason for the upstream transport of water pollution from the mouth of the Yeocheoncheon is the tides. The effects of organic content and stagnant water on water quality were analyzed using WASP. Moreover, the changes in water quality arising due to the removal of the grit chamber were analyzed. Results indicated that BOD improved by 18.8-100%, while T-P improved by 90.0-617.4%, between the grit chamber and Hanbi-Gyo , which is located 1.3 km away from the grit chamber.
The objectives of this study were to evaluate the effect of replacing 40% corn meal with three different types of barley (Youngyang, Wooho, and Yuyeon) on the chemical compositions, microbial indices, gas emission, and volatile fatty acid (VFA) content in feces of growing pigs. Sixteen pigs (Landrace × Yorkshire × Duroc) with an initial average body weight of 71 ± 2 kg were maintained in metabolic cages and randomly allotted to four treatments containing different sources of barley, for 23 days. The treatment with three different barley types replacing 40% ground corn showed no effect (P>0.05) on fecal chemical compositions, microbial indices, gas emission, and VFA. However, some differences (P<0.05) were noted in the chemical compositions of crude fiber and ash, and in the levels of Lactobacillus and Salmonella in the feces of the growing pigs. In conclusion, methane and hydrogen sulfide decreased by replacing 40% corn meal with Youngyang and Wooho barley, respectively.