• Food Science and Preservation
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• v.20 no.4
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• pp.459-466
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• 2013

This study was carried out in order to investigate sterilization effect and to extend storage periods of the Rubus coreanus by treating with tap water (TW), electrolyzed water (EW) and aqueous chlorine dioxide ($ClO_2$). After each treatment plot was soaked with 10, 50, 100, 200 ppm in each sterilizing solution within 30 sec, each treatment was compared during the storage time at room temperature and refrigerator temperature. As results of total plate count according to temperatures and periods, the microbial sterilizing power of each treatment plot was bigger at EW and $ClO_2$ treatment plots than the TW treatment plot; however, it sharply increased on the high concentration $ClO_2$ treatment plot. Futhermore, the cold storage treatment plot had more outstanding microbial sterilizing power than the room temperature treatment plot. As a result of observing the surface of the Rubus coreanus using scanning electron microscope (SEM), no microbe was seen in EW and $ClO_2$ treatment plot. The results of measuring enzyme activity showed a more significant decrease in EW and $ClO_2$ solutions treatment plot than TW treatment plot but gradually increased with time. The contents of total polyphenol revealed similar values on each treatment. The EW and $ClO_2$ treatment of the Rubus coreanus could be considered as good methods for inhibiting microbial growth in fresh vegetables and fruit, thereby contributing to quality maintenance.

• Food Science and Preservation
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• v.20 no.1
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• pp.111-120
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• 2013

Sprassis crispa was cultivated using soybean curd whey, and its antimicrobial activities were examined against those of eight microorganisms that were foodborne pathogens or food-poisoning bacteria. The culture broth of soybean curd whey was superior in mycelium content (17.76 g/L) to that of the defined culture broth, and the ${\beta}$-glucan content was about 10.64 percent (w/w). The antimicrobial activities of the culture broth were confirmed against those of B. cereus, St. aureus, L. monocytogenes and S. typhimurium using the paper disk method. The antimicrobial activity was also maintained after the heat treatment and alcalase treatment. The filtrate with less than 3 kDa M.W. also showed the antimicrobial activity against four strains: B. cereus, St. aureus, L. monocytogenes and S. typhimurium. The minimum inhibitory concentration (MIC) was about 1.26 mg/mL in the B. cereus and 12.6 mg/mL in the St. aureus and L. monocytogenes. The S. typhimurium showed a MIC of 62.8 mg/mL. Thus, the culture of Sparassis crispa using soybean curd whey provides a thermally stable antimicrobial agent that can be used as a natural preservative in the biofood industry.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.46-53
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• 2002

The study was carried out to determine the growth and biomass production of deciduous trees including Betula pendula, Fraxinus rhynchophylla, Cornus controversa subjected to artificial shade treatment of three levels in nursery field. The results were as follows; The height growth of seedlings was no difference subjected to artificial shade treatment. The root collar diameters of the relative growth rates of seedlings grown in full sun showed 29-32% as compared with those subjected to the shade treatment of 7-10% light intensities of full sun. Corrus controversa of the root collar diameters of the relative growth rates were better in the seedlings grown in 26-34% light intensities of full sun. Total dry mass including the dry mass of leaves, shoot and root were as a whole decreased with shade treatment. The ratio of the dry mass of leaves and stem increased the dry mass of root. T/R ratio of the seedlings increased by decreasing the relative light intensity. And the T/R ratio of 7-10% light intensities of full sun was ranged from 1.00~2.27 were greater in the full sun light was ranged from 0.51~l.13. Light intensity by artificial shade treatment decreased in deciduous trees when compared on the whole, it showed tendency that SLA increases, increased that seeing resemblant tendency in LAR and LWR and changed of light intensity is strong, it increased that showed difference as statistical.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.848-856
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• 2016

The purpose of this study is to determine the impact on settlement pattern of wintering swans by distribution of rapidly spreading lotus in Junam reservoir. When we investigated the relationship between the spreading lotus and population variation of the wintering swans in all around Nakdong-river estuary, the spreading lotus did not affect the number of swans in Junam reservoir. The occupation ratio of lotus distribution continuously increased from 13.2%(2013) to 19.0%(2014). Before we begin with the investigation, we compared two particular groups: inside of lotus community and far (>100 m) water area from the border of lotus community. At the first survey(2013.12.17), we observed 3.1 times more swan population in the inside, comparing with far water area. The third(2014.01.29.) and fourth(2014.12.03) inquiries also showed respectively 5.5 and 7.5 times higher swan population in the inside and near water area. The second observation was conducted during visitors were increased so these phenomenon was not observed. This result might be explained as the similar environmental condition of habitate for swan and lotus such as less than 1 m water depth. However, we considered that lotus and swan were not relation of conflict due to increasing both lotus community and swan population at the same time. According to the observation that inhabitation density of wintering swans is significantly high in near lotus communities area, at least spread of lotus did not negatively affect the wintering swans.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.218-224
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• 2015

Recently, removing methods of red tide has been attempted by filtering the organisms using the ceramic porous bodies. However, the marine biofouling could be developed on the surfaces of porous ceramic body after use for more than one month, and it might decrease the function of the specimen. In this paper, a method of inhibiting marine biofouling by changing the physical properties or surface-modification of ceramic porous body was studied. After experiment with six different ceramic porous bodies, it was found that the specimen of lower porosity and water absorption showed the least amount of biofouling. In addition, by increasing the surface roughness with silica particles bonded to the surface of specimen, the amount of biofouling caused by large marine life such as barnacle and mussel could be decreased. On the other hand, when the surface of specimen was coated and fused by glass powder, the amount of biofouling was rather increased. This might be due to eluted inorganic ions from the glass which can promote the growth of the microorganism. In conclusion, the environmental-friendly methods to reduce the amount of marine biofouling, such as controlling the physical properties and the surface roughness of the porous ceramics, can be possible without the use of dangerous substances. So it is expected for the results obtained to be applicable to a marine structure.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.1-5
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• 2004

Rutin has many beneficial effects on human health. It was established that rutin antagonizes the increase of capillary fragility associated with hemorrhagic disease, reduces high blood pressure, decreases the permeability of the vessels, and has an antiedema effect, reduces the risk of arteriosclerosis, and shows antioxidant activity. Rutin analysis with mulberry fruits was carried out by high-performance liquid chromatography (HPLC) to reveal the possibility of source of functional food. As a result, mean content of fifty accessions was 0.14±0.050% DW. Among the tested fifty accessions, 'Sabangso' was showed the highest rutin in 0.29%DW, whereas 'Simseol' was the lowest content in 0.05% DW. Also, we researched the change of rutin content according to harvested date. The rutin contents of earlier harvested groups were higher than later harvested groups. Simultaneously, fruity characteristics as well as rutin content were researched and analyzed to select the functional mulberry varieties for the production of fruit. From the six accessions which were contained high rutin content, we selected three suitable varieties such as 'Ficus', 'Kangsun', and 'Palcheongsipyung'.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.1
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• pp.10-18
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• 2017

Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.45-51
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• 1987

This experiment was conducted to find out the critical competitive period and competitive ability of rice against red rice. Plant height and number of tillers of rice decreased as red rice competed with rice during active tillering stage. The maximum tillering stage of rice competed with red rice became about 10days earlier than those non-competed. Significant yield reduction of rice was observed in the plots competed for 20 days after transplating or longer. Such a yield reduction can be mainly attributed to the decrease in number of panicles per hill and grain number per panicle. In a replacement diagram for rice and red rice, their competition is turned out being antagonized. The relative yield total was considered lower than 1. Grain number, culm and panicle length of rice was not affected significantly by inter-specific competition. Rice grain yield reduction was highly correlated with the number of panicles of red rice. Three hundred panicles/$m^2$ of the red rice were necessary to reduce rice grain yield by 50% of the check plot.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.17-22
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• 2016

Yellow tuft symptoms of a dense cluster on zoysiagrass (Zoysia japonica Steud.) occurred extensively at cultivated fields of zoysiagrass sods in Jangsung. The dense cluster of zoysiagrass showed significant morphological changes such as the tufts of shortening of internodes. The disease symptom was spread on a large scale throughout stolon nodes with multiple short leaves and it thrives in broom-like shaped clusters, exhibiting light green or yellow color on their leaves. The dense cluster of zoysiagrass had approximately 5.8 times more leaves on each node of its stolon then healthy zoysiagrass. Also, these zoysiagrass had poorly developed root and stolon caused by the tufts of a dense cluster of shoots. The dense cluster of zoysiagrass were collected for the putative causal agent incubation and upon close observation, it was found that the sporangia took the shape of a lemon, each sporangium was pointed at the end of its axis and was measured to be $60{\sim}96{\times}42{\sim}51{\mu}m$. These findings were analogous to the mycological characteristics of sporangia formed by the pathogen Sclerophthora macrospora. The symptoms of yellow tuft were prevalent in spring and autumn. Therefore, this study aims to present fundamental data in relation to yellow tuft on zoysiagrass in Korea.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.389-393
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• 2005

This study was carried out to investigate the effects of soil acidification on the growth of 3-year-old Pinus densiflora seedlings grown for 21 weeks in brown forest soils acidified with $H_2SO_4$ solution. The concentrations of Al in the acidified soils were increased with increasing amount of $H^+$ added to the soil. The total dry weight of the seedlings was reduced by the addition of the $H_2SO_4$ solution. In addition, there was a strong positive correlation (r=0.97, p<0.01) between the dry weight of the seedlings and the molar (Ca+Mg+K)/Al ratio of the soil. The seedlings with the molar (Ca+Mg+K)/Al ratio of 1.0 resulted from approximately 50% growth reduction compared with the control value. The results suggest that the molar (Ca+Mg+K)/Al ratio of the soil may be a useful indicator for assessing the critical load of acid deposition.