• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.466-474
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• 1998

This study was conducted to evaluate heavy metal concentrations(Cd, Cu, Z, and Pb) in the soil of two zinc mines and to correlate heavy metal contents between the soils and trees growing near the mines. Soils and leaves, stems, and roots of five tree species(Corylus heterophylla, Pinus rigida. Populus alba${\times}$glandulosa, Rhododendron mucronulatum, and Robinia pseudoacacia) were collected from Sambo Zinc Mine located in Hwasung and Gahak Zinc Mine in Kwangmyung city in Kyonggido. Soils near two zinc mines were not seriously contaminated by heavy metals, but Zn and Pb concentrations were at toxic level. The heavy metal concentration in soils decreased in the order of Zn, Pb, Cu, and Cd, and decreased with increasing distance from zinc mining sites. Among the five tree species, Populus alba ${\times}$ glandulosa showed the highest heavy metal concentrations in the tissue except for Pb. Particulars, leaves of the species contained the high concentrations of heavy metals to reach the maximum of 91ppm Zn. The roots of Corylus heterophylla contained high concentrations of Cu and Pb. The order of heavy metal concentrations in the tree species was Zn, Cu, Pb and Cd. The concentration of heavy metals in the tree tissues showed a positive correlation with that in soil in which trees are growing. The ratio of heavy metal concentration of trees to that of soils(concentration factor : CF) was highest in Zn and lowest in Pb. Populus alba${\times}$glandulosa had the highest CF value among the five tree species. It was concluded that Populus alba${\times}$glandulosa, based on the high metal uptake ability, could be used for decontaminating of heavy metals from contaminated soils, and Pinus rigida could be used to reflect the level of contamination in soils.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.404-414
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• 1998

The purpose of this study was to investigate the influence of air pollution using epiphytic lichens on forest trees around Ulsan and Onsan industrial complex from April to June, 1997. The distribution of lichens was investigated at 58 sampled sites. In this study, 16 kinds of epiphytic lichens were recorded, of them, Lepraria sp. having a tolerance to air pollution showed the highest frequency as 30.85%, and in order of Lecanora strobilina(26.18%) and Parmelia austrosinensis(13.42%) unknown to tolerance of air pollution. The number of lichens was gradually decreased around industrial complex, where so - called "lichen desert" was detected. As being distant from the industrial complex, the mean degrees of cover were increased. The degrees of cover in the investigated sites ranged from I to V. According to $SO_2$ concentration limiting lichen's growth, the pattern of distribution of Cladonia sp., Dirinaria applanata, Parmelia austrosinensis, Lepraia sp. and Lecanora strobilina were dissimilar by sensitivity to air pollution Especially Lepraria sp. and Lecanora strobilina were widely distributed to degree of cover from I to V, and as the both had a similar distribution pattern, it could be inferred that Lecanora strobilina had also a tolerance to air pollution. The IAP values ranging from 0 to 64.3 were arranged into six groups and the investigated area was delineated into six IAP zones to represent degree of air environment. It was a high IAP value as being distant from industrial complex. The mare IAP increased, the more number of kinds of lichens increased. It was confirmed that the number of species, coverage and IAP value of epiphytic lichens showed a tendency to decrease of urban area and industrial complex.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1041-1048
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• 2012

Shiitake mushroom (SM; Lentinus edodes) are cultivated and consumed in many Asian countries including Vietnam, China, Japan, Korea, and Thailand. In Asia, SM are mainly dried and used as flavoring. The aim of this study was to compare the effects of SM created with different drying processes, such as oven-dried and sun-dried, on the antioxidative and antigenotoxic effects. Raw and dried SM were extracted with acetone, ethanol, methanol, and hot water. The antioxidant effects of SM were evaluated by determining total phenolic content, DPPH radical scavenging activity (RSA), an ORAC assay, and a cellular antioxidant capacity (CAC) assay. The inhibitory effect of SM on oxidative stress-induced DNA damage in human leukocytes was evaluated by a Comet assay. The total phenolic content of raw SM extracted with methanol and of that extracted with water were significantly higher than the dried SM. Among the water extracts, the $IC_{50}$ for DPPH RSA of raw and sun-dried SM were significantly higher than that of oven-dried SM. Sun-dried SM showed the most potent ORAC value at 50 g/mL. The CAC against $AAPH^-$ induced oxidative stress in HepG2 cells, and $H_2O_2$ induced DNA damage were effectively protected against by all SM extracts. These results suggest that unprocessed SM are the best antioxidants, and that the sun-dried method would be the best option to use in terms of antioxidant activity and the antigenotoxic effect.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.235-245
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• 1993

This study was carried out to understand the stand structure based on the compositional characteristics of natural deciduous forest dominated by Quercus species, which will provide with fundamental ecological and silvicultural information for effective forest management. Of two tracts selected from the Seoul National University Research Forests, one is located in Kwangju-Gun Kyunggi-Do, and the other in Kwangyang-Gun Chollanam-Do. Point-quarter sampling method w-as employed to survey woody vegetation confined to larger than 6cm in DBH. The numbers of sample points were 152 and 187, in Kwangju-Gun and Kwangyang-Gun, respectively. Comparative analysis for two forest tracts was made as follows ; 1) species composition by calculation of importance values ; 2) number of stems per hectare for major tree species ; 3) species diversity for the forests in two locations ; 4) inter-species association based on $X^2$ test. The relative dominate of Quercus speices showed 88% at Kwangju-Gun, Kyunggi-Do and 50% at Kwangy-ang-Gun. Chollanam-Do. Such high dominance occurred due to high importance values of Quercus variahilis and Q. mortgolica in both locations. Quercus serrata showed low value at Kwangju-Gun. Kyunggi-Do whereas Q. acutissirna, Q. dentata and Q. aliena did none at Kwangyang-Gun. Chollanam-Do. The species diversity and evenness in oak communities exhibited 0.82 and 0.61, respectively at Kwangju-Gun. Kyunggi-Do, while those did 1.09 and 0.73 at Kwangyang-Gun, Chollanam-Do. Therefore, it was considered that Ku-angju-Gun region was disturbed severely by human activities but Kwangyang-Gun region eras less disturbed. Frequent appearance of Carpinus and Acer species indicates increase in diversities and better development of succession at Kwangyang-Gun region.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.238-247
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• 2006

The purpose of this study was to evaluate school dieticians' performance of nutritional quality control, and further to establish effective and objective standards of nutritional quality control. Data for this study came from 200 school dieticians' responses in the Chungbuk area. The total quality management (TQM)-based questionnaire was structured. The questionnaire consisted of the following four fields (1) performance of nutritional quality control, (2) performance of stepwise food production to maximize nutrient preservation rate, (3) management of documents and records related to nutritional quality control, and (4) other relating matters. The items of the questionnaire were measured on a five-point Likert scale which ranged from 'strongly agree' to 'strongly disagree'. First, the analysis indicated that school dieticians performed 'least' on human resource management', 'mediocre' on nutritional quality control, and best on 'leadership'. Second, the analysis on performance of stepwise food production to maximize nutrient preservation rate showed that dieticians considerably endeavored to maximize nutrients of cooked food, but it was found out that the most of nutrient destruction can be caused by heating during cooking. Third, the result showed that the systematic use of documents and records for nutritional quality control was not sufficiently accomplished, especially in the production phase of food. In addition, the measure by the Pearson correlation coefficient indicated that there was a significant relationship between performance of nutritional quality control and performance of stepwise food production to maximize nutrient preservation rate, and between performance of nutritional quality control and management of documents and records related to nutritional quality control. Finally, the findings of this study suggest that more effort should be exerted to carefully establish TQM-based standards for the improvement of nutritionary quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.62-67
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• 1999

Infection rates of oyster ovarian parasite, Marteiliodes chungmuensis and productivity of the oyster shellstock infected with the parasite were investigated at the main seed collection areas in the southern coast of Korea where the extreme bad seed collection of oyster occurred in 1992 and 1993 to evaluate the cause of the bad seed collection. Additionally, the bacterial flora of the sea water and oyster lana were examined to identify the shellfish larva pathogenic bacteria like Vibrio sp. and Pseueomonas sp. In August 1992 to September 1993, infection rate of oyster ovarian parasite, M. chungmuensis at Tongyong, Kyongsangnam province, and Yosu, Chollanam province where the bad seed collection occurred, were $11.8\~100\%$ and $14.3\~100\%$, respectively. But the parasite was not detected in the shellstock collected at Daechon, Chungchongnam province. While a virus-like particle was identified in the cytoplasm of the egg infected by the parasite. The parasite infected egg was not able to fertilize completely. Uninfected egg in the gonad contaminated by the parasite could be able to fertilize but showed an abnormal development till D-shaped larva and then, died of necrosis after D-shaped lana. And some lana developed from low lipid content egg could not develop to the spat and died after the early umbo stage. The predominant bacteria in the oyster lana collected at bad seed collection areas were Pseudomonas sp. and Pseudomonas like bacteria and the occupancy rates were $53.3\~87.1\%$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.299-306
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• 2014

Fresh edible sweet corns demand relatively short period to harvest fresh ears, which can allow farmers to make a choice sweet corns for various cropping systems. For this reason, we were to find the optimum planting date of late-planted sweet corns to sell fresh ears in the autumn linked to cropping system with winter crops, investigating yield and properties of marketable fresh ears and growth traits of sweet corns (cv. 'Godangok' and cv. 'Guseulok') depending on planting dates such as 10 July, 20 July, and 30 July in Suwon 2012 and 2013, respectively. The 20 July-planted sweet corns showed the most fresh ear yield. However, the 10 July-planted and the 30 July-planted had 32% less yield caused by consecutive rainfall from 10 July through 20 July, and 15% less yield due to low air temperature during ripening than the 20 July-planted, respectively. The 10 and 20 July-planted sweet corns had average 140g of a fresh ear weight and 15% heavier ear than the 30 July-planted. For the July-planted sweet corns, silking days after planting ($r=-0.80^{**}$), and harvesting days after silking ($r=-0.97^{**}$) and planting ($r=-0.91^{**}$) were highly negatively correlated with daily mean air temperature during the period, resulting in it takes 1,100 growing degree days (GDD) to harvest fresh ears from the July-planted sweet corns. The fresh ears of the 20 July-planted sweet corns are able to be harvested by early October. Therefore it will be a good choice for the cropping system based on winter vegetable cash crops such as temperate garlic and onion with medium or late maturity. Among three planting dates 20 July-planted sweet corns had the best field performance in every year considering fresh ear yield, ear size, and stability to grow.

• Economic and Environmental Geology
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• v.49 no.2
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• pp.121-134
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• 2016

We characterize the spatial distribution of Cobalt-rich ferromanganese crusts covering the summit and slopes of a seamount in the western Pacific, using acoustic backscatter from multibeam echo sounders (MBES) and seafloor video observation. Based on multibeam bathymetric data, we identify that ~70% of the summit area of this flattopped seamount has slope gradients less than $5^{\circ}$. The histogram of the backscatter intensity data shows a bi-modal distribution, indicating significant variations in seabed hardness. On the one hand, visual inspection of the seafloor using deep-sea camera data exhibits that the steep slope areas with high backscatter are mainly covered by manganese crusts. On the other hand, the visual analyses for the summit reveal that the summit areas with relatively low backscatter are covered by sediments. The other summit areas, however, exhibit high acoustic reflectivity due to coexistence of manganese crusts and sediments. Comparison between seafloor video images and acoustic backscatter intensity suggests that the central summit has relatively flat topography and low backscatter intensity resulting from unconsolidated sediments. In addition, the rim of the summit and the slopes are of high acoustic reflectivity because of manganese crusts and/or bedrock outcrops with little sediments. Therefore, we find a strong correlation between the acoustic backscatter data acquired from sea-surface multibeam survey and the spatial distribution of sediments and manganese crusts. We propose that analyzing acoustic backscatter can be one of practical methods to select optimal minable areas of the ferromanganese crusts from seamounts for future mining.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1226-1232
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• 2003

Bamboo trees have been used for a long time as folk remedies for treatment of hypertension and stroke symptoms in Oriental regions. These pharmaceutical effects of bamboos look like to be related to its antioxidant capacity and phytochemicals in bamboos. To evaluate the antioxidative effects of bamboo trees, five kinds of bamboo varieties dominant in Korean peninsular were chosen and determined its total antioxidaive activities, free radical scavenging activities and nitrite scavenging activities by TEAC (Trolox Equivalent Antioxidant Capacity) assay, DPPH and Griess reagent assay using in vitro system, respectively. To evaluate the correlation between antioxidative activities and Maillard reaction during hot water extraction, contents of reducing sugar and total nitrogen and brown color intensity at 420 nm were determined. When total antioxidative activities, free radical scavenging activities and nitrite scavenging activities of five kinds of bamboo trees were compared, wang-dae (Phyllostachys bambusoides S. et Z.) showed the strongest effect among samples, although all kinds of extracts showed relatively strong effects against oxidation. The bamboo culms extract showed stronger antioxidative effects than that of bamboo leaves. In each fraction obtained from 70% ethanol extract, antioxidative effect were increased in order of dichloromethane>ethyl acetate>butanol>water>hexane fraction. In reducing sugar analysis of extracts, reducing sugar contents of water extracts were higher than that of 70% ethanol extracts and wang-dae water extract showed the highest level which was 708.92 mg/g. Total nitrogen contents of the extracts were $1.785{\sim}2.605\;mg%$ and contents in water extracts were lower than that in 70% ethanol extracts. Brown color intensity at 420 nm showed similar tendency with results in reducing sugar contents.

• Journal of the Mineralogical Society of Korea
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• v.25 no.3
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• pp.163-173
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• 2012

In this study, we determined the relative clay mineral composition of 51 surface sediments from SEYSM (Southeastern Yellow Sea Mud) (northern part 25, southern part 26) and 30 river sediments inflow to Yellow Sea using the semi-quantitative X-ray diffraction analyses. In addition to we analyzed illite characteristics of the same samples. The clay-mineral assemblage is composed of illite (61~75%), chlorite (14~24%), kaolinite (9~14%), and smectite (1~7%), in decreasing order. The average composition of each clay mineral is not different from northern part to southern part of SEYSM except a little higher kaolinite and lower smectite content in northern part. Smectite content generally has reverse relationship with illite content. Mineralogical characteristics of illite such as illite crystallinity index also is not different between two areas and show very narrow range (0.18~0.24 ${\Delta}^{\circ}2{\theta}$). Our results reveal that clay mineral composition and illite characteristics are nearly the same between northern and southern part of SEYSM. Characteristics of surface sediments in SEYSM is closer to Korean river sediments than Chinese Hanghe sediments, however it is necessary to investigate further study including Yangtze river sediments. This study conclude that most of surface sediments in SEYSM attribute to the supply of considerable amount of sediments from the nearby Korean rivers. The large sediment budget and high accumulation rate in the SEYSM can be explained by erosion and reworking of surface sediments in this area. Tidal and regional current system around SEYSM might contribute these erosional and depositional regimes.