• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.71-81
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• 2013

Trace metal concentration in sediment cores from the outer sea of Lake Shihwa were determined to study the vertical profiles of metal concentrations and to evaluate the levels of metal contamination. Sediment pollution assessment was carried out using enrichment factor (EF) and geo-accumulation index (Igeo). The mean concentration of metals were 58.8 mg/kg for Cr, 10.3 mg/kg for Co, 22.8 mg/kg for Ni, 18.1 mg/kg for Cu, 74.0 mg/kg for Zn, 6.75 mg/kg for As, 0.14 mg/kg for Cd, 27.4 mg/kg for Pb and 0.026 mg/kg for Hg, respectively. The mean EF values for Cu, Zn, As, Cd and Hg were greater than 1.5 in sediment cores, indicating that these metals in sediments are slightly enriched by anthropogenic activities. The geo-accumulation index (Igeo) suggested unpolluted status for metals of sediments collected from outer see of Lake Shihwa. Igeo values for Cu and Hg nearby LNG station (site C, D, E) ranged from 1 to 2, indicating moderately to unpolluted pollution status for those metals. Even if the higher concentrations of trace metals nearby LNG station were observed, there is significantly positive relationship between Al and trace metals. Thus, the sediment grain size plays an important roles in influencing the distribution of trace metals in sediment cores from the outer sea of Lake Shihwa. Based on the comparison with sediment quality guidelines such as threshold effect level and probable effect level in Korea, the concentration of metals in sediments from outer sea of Lake Shihwa are likely to result in no harmful effects on sediment-dwelling organisms.

• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.71-80
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• 2011

This study was conducted to investigate the effects of dietary supplementation of CS682, a fermentation product of Actinomycetae Nocardia sp. CS682, and DCS682$^{(R)}$, a commercial product, on the performance, blood parameters, small intestinal microflora, and immunoglobulin contents in broilers. In Exp. 1, a total of 240 ROSS$^{(R)}$ broiler chickens of 1d old were assigned to six dietary treatments: Control, Antibiotics (6 ppm avilamycin), CS682-0.25 (CS682 0.25%), CS682-0.50, CS682-0.75 and CS682-1.00. There were significant (p<0.05) differences among treatments in feed conversion. The CS682-0.25 treatment was significantly (p<0.05) lower than Antibiotics and other CS682 treatments in 0~2 wk feed conversion. The CS682 treatments influenced MCV (mean corpuscular volume) in blood. The cfu of Escherichia coli in small intestinal content was lowest in Antibiotics treatment followed by CS682 treatments and Control. In Exp. 2, a total of 1,000 ROSS$^{(R)}$ broiler chickens of 1 d old were assigned to five dietary treatments: Control, Antibiotics (6 ppm avilamycin), DCS682-0.05 (DCS682$^{(R)}$ 0.05%), DCS682-0.10 and DCS682-0.20. There were significant differences (p<0.05) among treatments in mortality. The DCS682-0.20 treatment was lower than DCS682-0.10 in 0~3 wk and lower than Control in 0~5 wk mortality. Antibiotics treatment was lowest in all microbial population in small intestinal content. The cfu of E. coli and Salmonella typhimurium of DCS682 treatments were higher than Antibiotics treatment but lower than the Control. The results of present broiler experiments indicated that supplementation of 0.20~0.25% CS682 and DCS682, improve feed conversion, mortality and control harmful intestinal microbes.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.161-170
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• 2008

Recently irregular dark-colored patches were found on the Kentucky teeing ground in a golf course in Gyunggi providence. Interestingly, blue-green algae from the leaf tissue sample containing black spot-stained symptoms were largely observed through microscopic study. In general, algae present on the upper soil surface or in the upper layer of root zone form dark brown layers of scum or crust, which invoked harmful effects to turf growth such as poor drainage, inhibition of new root development. In this observation, unlike the algae were sometime found in senescing leaves on contacted soil in July and August, the blue-green algae were detected within black spot-stained Kentucky bluegrass leaf tissues including leaf blade, ligule, auriclea as well as leaf sheath. The blue-green algae were also detected on the leaf and stem tissue adjacent to the symptomatic leaf tissues. Two species of blue-green algae, Phomidium and Oscillatoria, were greatly observed. Oscillatoria species was more commonly notified in all samples. In addition, the two species were found on a putting green showing yellow spot disease at another golf course in Gyunggi providence. The data from chemical control assay revealed that chemicals such as propiconazole, iprodione, and azoxystrobin decreased blue-green algae population and leaf spots, which finally resulted in enhanced leaf quality. All taken together, we strongly suggested that the disease-like phenomenon by blue-green algae might be very closely mediated with infection/translocation process in relation with turfgrass. It indicates that blue-green algae in turf management may play an adverse role as a secondary barrier as well as a pathogenic agent. This report may be helpful for superintendents to recognize and understand the fact that algae control should be provided more cautiously and seriously than we did previously in upcoming golf course management.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.275-281
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• 2018

It is known that he pollutant emitted from the combustion process of marine fuel oil causes air pollution and harmful effects to the human body. Accordingly, IMO regulates pollutants emitted from ships. However, the regulation of Particulate Matter (PM) is still in the process of debate, so preemptive action is needed. Fundamental research on PM is essential. In this study, the Dimensionless Light Extinction Constant ($K_e$) of fuel oil used in marine diesel engines was measured and analyzed to construct the basic data of the PM generated from marine-based fuel oil. The fuel oil used in the land diesel engine was measured in the same way for character comparison. Both fuel oils differ in sulfur content and density. The $K_e$ was measured via the optical method using a 633 nm laser and was determined by using the volume fraction of PM collected by the gravimetric filter method. The $K_e$ of the PM discharged from marine fuel oil is 8.28, and the land fuel oil is 8.44. The $K_e$ of two fuel oils was similar within the measurement uncertainty range. However, it was found by comparison with the value obtained by the Rayleigh-Limit solution that the light scattering portion could be large. Also, it was found that light extinction characteristics could be different due to the relationship between light transmittance and collected mass.

• Journal of the Korean Dietetic Association
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• v.8 no.3
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• pp.269-279
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• 2002

To investigate the change of perception after weight management education in elementary, middle and high school students, a survey was conducted. Same questionnaire was administered twice, before and after weight management education, to 426 students at 9 schools in Seoul area. The mean height, weight and body mass index were 145.5$\pm$8.0cm, 40.0$\pm$8.3kg, 18.6$\pm$3.0 for elementary school students, 160.1$\pm$5.2cm, 50.2$\pm$7.3kg, 19.5$\pm$2.4 for middle school students, and 162.2$\pm$5.0cm, 52.2$\pm$6.4kg, 19.8$\pm$2.3 for high school students, respectively. Before education, their preferred weight and perceived healthy weight was 35.4kg and 37.0kg among elementary school students, 44.8kg and 46.5kg among middle school students, and 47.3kg and 48.9kg among high school students, respectively. Differences between their present body weight and their preferred weight and/or perceived healthy weight appeared to be 4.5kg and 2.9kg in elementary school students, 5.6kg and 4.0kg in middle school students, and 5.1kg and 3.3kg in high school students, respectively. After administering education, the differences decreased to 2.5kg and -0.2kg in elementary school students, 4.2kg and 2.7kg in middle school students, and 4.3kg and 2.0kg in high school students, respectively (p<0.01). And their perception on own body shape was investigated using 5 point scale ('too lean' to 'too fat', 1 to 5) before and after education. The mean values changed from 3.1 to 2.8 in elementary school students, from 3.3 to 3.0 in middle school students, and from 3.4 to 3.2 in high school students (p<0.01). Their satisfaction with own body weight was monitored using 5 point scale ('very satisfied' to 'very unsatisfied', 1 to 5), also. The mean values changed from 3.0 to 2.7 in elementary school students, from 3.6 to 3.2, in middle school students, and from 3.8 to 3.4 in high school students (p<0.01). In the evaluation of their nutrition knowledge about weight control using 10 item quiz, before and after education, the mean quiz score was changed from 6.3 to 7.0 in elementary school students, from 7.0 to 7.9 in middle school students, and from 7.5 to 8.1 in high school students (p<0.01). In summary, nutrition education on weight management improved the subject's perception on perceived healthy weight and own body shape, and satisfaction with present body weight. This result suggests that nutrition education program should incorporate strategies to change incorrect beliefs and knowledge regarding weight control. Onto this, weight control education for students should start from their early age, be repeated periodically and consistently, and focus on the harmful effects of excessive weight loss and information on the practical and scientific ways of weight management.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.25-25
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• 2014

Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.11-16
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• 1987

With the purpose of pursuing the increase and decrease of chlorophyll a and chlorophyll b caused by application of the simulated acid rain treatment on Pinus koraiensis seedlings and Ligustrum obtusifolium cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College, during the growing season of 1985. Pinus koraiensis seeds stratified in cool and moist condition were sown on pots, and in case of Ligustrum obtusifolium, C1/1 cuttings were potted for experimental use in the early spring. The regime of artificial acid rain, based upon precipitation frequency and density, was simulated from the learning of climatological data averaged from 30 years records. The spray of acid water containing pH values of 4.0 and 2.0 was initiated from the 1st of May and ended on the 31st of August. As control, ground water was also treated at the same time. To analyse the chlorophyll content, those leaves looking representative and unaffected by other harmful agents were sampled on the 18th of September, and UV-visible spectrophotometer was used. With decrease in pH values of acid rain, the content of chlorophyll a and chlorophyll b decreased in both species. The decrease in chlorophyll a could be confirmed through statistical significance, but not in chlorophyll b. And when we discussed the chlorophyll decrease index which was explained in detail in the paper, an attention might be given to similarly decreasing values in both chlorophyll a and chlorophyll b, according as pH levels of acid rain decreased. The ratios of chlorophyll a to chlorophyll b in both species were not affected by different pH leaves of acid rain.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.203-207
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• 2009

The concern of seriousness and harmful effects of environmental pollution is rising by the various water pollutions, appearances of new micro-noxious substances and increase of sustainable pollutants. The method is suggested that can effectively increase the removal of organic substances and several pollutants using a coagulation process. The experiment for characteristics of $ZrSiO_4$ (zirconium silicate) as a coagulation-aid was carried out for application to coagulation process with domestic wastewater and lake water, and the removal rate of the organic substances depending on a dosage was evaluated by PDA (Photometric Dispersion Analyzer) in this study. Zeta-potential of zirconium silicate solution was -32.22 mv at pH 7 and the lower negative(-) charge was detected in the more acidic conditions. Absorbance on $UV_{254}$ presented higher when zirconium silicate was added than in a domestic wastewater itself. Besides, the results by PDA experiment represented that injection of zirconium silicate could promote growing of floc. Tests for coagulation process were conducted by three ways which are pre-injection, co-injection and post-injection of zirconium silicate with alum. Accordingly, removal efficiency of organic substances increased over 15% in co-injection than in using of alum as a sole reagent. When a 20 mg/L of alum was used with a 10 mg/L of zirconium silicate, the removal efficiency was high up to 90%. Removal efficiency of $COD_{Cr}$ was improved more than 15% in case of dosage of coagulant either PAC (Poly aluminium chloride) or PACS (Poly aluminium chloride Silicate) together with zirconium silicate. As a result, the removal efficiency of $COD_{Cr}$ were 5~10% higher in a co-injection of zirconium silicate with a coagulant than a pre-injection and a post-injection but it of soluble substances was lower in a co-injection.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.369-392
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• 2021

This study aimed to provide basic data for efficient flora management of vascular plants, halophytes, and naturalized plants in the Gwangpo Bay area in Sacheon city, Gyeongsangnam-do. The flora found in this area incorporated 520 taxa, including 93 families, 299 genera, 466 species, 3 subspecies, 41 varieties, and 10 forma, and accounted for approximately 10.6% of total vascular plants (4,884 species) in Korea. According to the survey, 76 species of Gramineae showed the highest frequency (14.6%), followed by 67 species of Compositae (12.8%), 34 species of Leguminosae (6.5%), 27 species of Cyperaceae (5.2%), and 22 species of Rosaceae (4.2%). Rare plant species designated by the Korea Forest Service were categorized into six taxa, including three taxa in the LC grade, one taxon in the CR grade, one taxon in the VU grade, and one taxon in the EN grade. Korea endemic plants belonged to nine taxa consisting of seven families, seven genera, and nine species. The special floristic plants included 44 taxa, including one taxon (Prunus yedoensis) in the V grade, four taxa in the IV grade, ten taxa in the III grade, six taxa in the II grade, and 23 taxa in the I grade. Naturalized plants included 62 taxa consisting of 15 families, 47 genera, 59 species and 3 varieties. Halophytes consisted of 27 taxa, including 13 families, 24 genera, 24 species, 2 varieties, 1 forma, which consisted of Atriplex gmelinii, Suaeda glauca, Suaeda maritima, and Lathyrus japonicus. Invasive alien species in the Gwangpo Bay area included seven taxa. Since Ambrosia artemisiifolia, Sicyos angulatus, andPaspalum distichum var. indutummay have harmful effects on native plants, these plants must be artificially controlled.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.965-973
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• 2021

Since radiation therapy is irradiated with high-energy X-rays in a variety of at least 20 Gy to 80 Gy, a high dose is administered to the local area where the tumor is located, and various side effects of some normal tissues are expected. Currently, in clinical practice, lead, a representative material, is used as an effort to shield normal tissues, but lead is classified as a heavy metal harmful to the human body, and a large amount of skin contact can cause poisoning. Therefore, this study intends to manufacture a measurement sheet that can compensate for the limitations of lead using the materials Tungsten, Brass, and Copper of the 3D printer of the FDM (Fused Deposition Modeling) method and to investigate the penetration performance. Tungsten mixed filament transmission measurement sheet size was 70 × 70 mm and thickness 1, 2, 4 mm using a 3D printer, and a linear accelerator (TrueBeam STx, S/N: 1187) was measured by irradiating 100 MU at SSD 100 cm and 5 cm in water using a water phantom, an ion chamber (FC-65G), and an elcetrometer (PTW UNIDOSE), and the permeability was evaluated. As a result of increasing the measurement sheet of each material by 1 mm, in the case of Tungsten sheet at 3.8 to 3.9 cm in 6 MV, the thickness of the lead shielding body was thinner than 6.5 cm, and in case of Tungsten sheet at 4.5 to 4.6 cm in 15 MV. The sheet was thinner than the existing lead shielding body thickness of 7 cm, and equivalent performance was confirmed. Through this study, the transmittance measurement sheet produced using Tungsten alloy filaments confirmed the possibility of transmission shielding in the high energy region. It has been confirmed that the usability as a substitute is also excellent. It is thought that it can be provided as basic data for the production of shielding agents with 3D printing technology in the future.