• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.11-16
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• 2013

Salmonella is closely related with human health of modern society which has concern increased in livestock goods consumption as well as give economic damage throughout the chicken industry such as farm, hatchery, slaughter house and processing plant. From 2007 to 2011, this study investigated Salmonella prevalence from 200 old hen delivery trucks which deliver old egg-laying hens and broiler breeders in Korea. The prevalence of Salmonella species was 38.0% in old hen delivery truck. Serogroup C1 was the most frequently detected serogroup of Salmonella, followed by the serogroups D1, C2 and B. A total of 25 serotypes were identified and Salmonella infantis was the most frequently isolated serotype. In addition, we applied disinfectant to old hen delivery truck for the reduction of Salmonella contamination. The disinfectant consists of formaldehyde, glutaladehyde and quaternary ammonium compound was applied to the trucks. Salmonella isolation rate was significantly decreased after disinfection from 38.0% to 7.5%. Disinfectant could not effectively reduce Salmonella contamination at a dilution of 1:200 which is recommended by manufacturer, but Salmonella isolation rate was significantly decreased at a dilution of 1:50. Since old hen delivery truck could be a potential vector to carry Salmonella into farms and abattoirs, chicken delivery truck should be disinfected thoroughly and sufficiently to control contamination of farms and abattoirs.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.339-344
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• 1986

Frost damage which can reduce yields, impair fruit quality and cause loss of trees is closely related to the occurrence of daily minimum temperature. Horizontal distribution of air temperature minima can be characterized by conditions of radiational cooling and gravitational movement of cold air, which are influenced by the regional topographic features. Observations were made on the air temperature minima over Yangpyeong area, to delineate potential effects of topography on the temperature pattern during spring season. Two routes were selected for the observation. Liquid glass minimum thermometers were installed at 17 sites through the old peach orchards which had been closed due to the frequent freeze-frost hazards during the recent years. This route was 8.5km long and the highest point was 350m above mean sea level. The other route, which was 2.5km in distance, was run with a digital resistance thermometer during the hour just before sunrise. Observations were made both on a calm-clear day (April 30, 1986) and a windy-overcast day (May 1, 1986). The temperature on April 30 was in increasing trend with elevation but this was modified at near the riverside and the downtown area. An orchard lying on a hilltop showed the temperature $1^{\circ}C$ higher than near by lowland of which elevation was about 30m lower. The minimum temperature on the overcast day was little affected by terrestrial conditions but by the atmospheric lapse condition. The peach orchards severely damaged by cold air were found in the area where the lowest minimum temperature was observed. The results may be useful for selection of the proper orchard location to be developed in an area.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.101-108
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• 2005

Because the stone cultural properties located outdoors, they have been altered and deteriorated in external appearance due to environmental factors such as acid rain, extreme change in temperature, and salts. Damage to stone cultural properties is accelerated particularly due to recent industrial development and environmental pollution. An experimental study was conducted to evaluate the effect of environmental contaminants on the weathering of granite. And as part of the developing of conservation method, $TiO_2$ catalyst was prepared and tested. When fresh granite was dipped into the salt and acid solutions, dissolution rate of eight minerals (Si, Mg, Ca, Na, K, Fe, Mn, Al) are abruptly increased at initial stage of reaction and then increased steadily until 100 cycles. After salt and acid solution experiments, the mineral compositions of the granite surface were lower then that of the fresh granite and density of the weathered granite was steadily decreased from $2.60\;g/cm^3$ to $2.56\;g/cm^3$, but Poissions ratio and absorption ratio were slightly increased. It was expected at stone cultural assets could be weathered by salts and acid rain. In the case of $TiO_2$ was coated to the granite, the dissolution rate of minerals and absorption ratio of $TiO_2$ coated granite were decreased. Therefore, the $TiO_2$ coating method tested in this study considered to be a viable method to assist in the conservation of stone cultural properties from environmental contaminants.

• The Korean Journal of Nuclear Medicine
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• v.35 no.5
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• pp.313-323
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• 2001

Purpose: The purpose of this study was to search activated genes that could be related to radiation adaptive response (RAR) induced by low-level radiation from $^{99m}Tc$ in human cell lines. Methods: We used gene discovery array (GDA) and representational difference analysis (RDA) methods. $^{99m}Tc$-pertechnetate was added to $2{\times}106/mL$ NC-37 cells (human lymphoblastic cells) to make concentrations ranging from 148 MBq/mL to 148 Bq/mL by serial 10 fold dilutions. After 44 hours, 2 Gy gamma irradiation was given to them using a Cs-137 cell irradiator. Results: As compared to the control (Con) group to which no $^{99m}Tc$ was added, those cells to which 148 and 14.8 KBq of $^{99m}Tc$ were added showed significantly lower damage to chromosomes, which was evaluated by metaphase analysis. Cells with 148 KBq $^{99m}Tc$ (T148 group) showed most significant protection. Activated genes in the T148 group as compared to Con group were evaluated by GDA and GDA methods. GDA revealed genes of casein kinase 2 (CK2) beta chain, immunoglobulins (lg), human leukocyte antigen (HLA)-B, and two novel genes. Twenty RAR related clones were selected by RDA method. The size of those genes was from 234 to 603 base pairs. Conclusions: RAR was induced by low dose irradiation from $^{99m}Tc$ in NC-37 cell lines. Genes related to the response included CK2, lg, HLA-B in human lymphoblastic cell lines.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.104-111
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• 2007

As protein content of milled rice, generally used as a benchmark for rice eating quality, is greatly affected by N fertilization and nutrition status of rice plant, understanding its response to nitrogen rate and plant nitrogen status at different growth stage is important for recommending N fertilizer management for high quality rice production. The responses of milled-rice protein content were compared and quantified under various combinations of basal+tillering and panicle N application levels in 2001 and 2002. Protein content of milled rice was ranged from 6 to 9%, increasing significantly with increasing basal+tillering and panicle N rates. However, milled rice protein content was raised much greater by panicle N than by basal+tillering N fertilization. Even though basal+tillering N increased up to 20 kg/ha, protein content of milled rice was observed less than 7% in case that panicle N was applied below 1.8 kg/10a. Regression analysis revealed that nitrogen accumulated until harvest was partitioned with almost constant rates of 58.3% and 46.5% to panicle and milled rice, respectively. The partitioning rates was slightly but not significantly different between experimental years. Protein content of milled rice showed linear and quadratic responses to the shoot N accumulation until panicle initiation stage (PIS) ant shoot nitrogen accumulation from PIS to harvest, respectively. The increment of milled-rice protein content per unit N increase was much greater in shoot N accumulation from PIS to harvest than in that until PIS. Regardless of shoot N accumulation until PIS upto 8 kg/10a, protein content of milled rice was lower than 7% and ranged from 6.5 to 7.5% in case that shoot N accumulation from PIS to harvest was below 3.0 kg/10a and below 6.0 kg/10a respectively. It would be concluded that even under the same N accumulation until harvest milled rice protein content could be different according to the N fertilizer management and weather condition especially during ripening, providing rooms for controlling protein content by N fertilizer management without damage to grain yield.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.1
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• pp.48-57
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• 2015

In a sodium-cooled fast reactor, which is a Generation-IV reactor, refueling is conducted by rotating, but not opening, the reactor head to prevent a reaction between the sodium, water and air. Therefore, an inspection technique that checks for the presence of any obstacles between the reactor core and the upper internal structure, which could disturb the rotation of the reactor head, is essential prior to the refueling of a sodium-cooled fast reactor. To this end, an ultrasound-based inspection technique should be employed because the opacity of the sodium prevents conventional optical inspection techniques from being applied to the monitoring of obstacles. In this study, a ranging inspection technique using a plate-type ultrasonic waveguide sensor was developed to monitor the presence of any obstacles between the reactor core and the upper internal structure in the opaque sodium. Because the waveguide sensor installs an ultrasonic transducer in a relatively cold region and transmits the ultrasonic waves into the hot radioactive liquid sodium through a long waveguide, it offers better reliability and is less susceptible to thermal or radiation damage. A 10 m horizontal beam waveguide sensor capable of radiating an ultrasonic wave horizontally was developed, and beam profile measurements and basic experiments were carried out to investigate the characteristics of the developed sensor. The beam width and propagation distance of the ultrasonic wave radiated from the sensor were assessed based on the experimental results. Finally, a feasibility test using cylindrical targets (corresponding to the shape of possible obstacles) was also conducted to evaluate the applicability of the developed ranging inspection technique to actual applications.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.389-398
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• 1984

The effect of N forms ($NO_3{^-}-N$, $NH_4{^+}-N$) and concentrations (4, 8, $16meq/{\ell}$) which were changed at head formation stage on the tip-burn incidence of chinese cabbage was studied under the three levels (0, 8, 16 meq/l) of Ca. All of the plants grown on $NH_4{^+}-N$ showed the symptoms of tip-burn and low yields regardless of Ca levels. Roots of plants grown on $NH_4{^+}-N$ were severely damaged. The pH of the leachate from $NH_4{^+}-N$ pot was decreased to below pH 5. Plants which had been grown on $NH_4{^+}-N$ before the head formation stage, but changed to $NO_3{^-}-N$ were recovered from abnormal growth. But, the reverse showed the tip-burn symptoms. $NH_4{^+}-N$ treatments increased the T-N contents, but lowered K and Ca contents of inner leafblades. Icreased applications of Ca did not affect the T-N and K contents of the inner leafblades. $NH_4{^+}-N$ suppressed Ca translocation into the inner leaves from outer leaves after the head formation stage, but $NO_3{^-}-N$ accelarated it. Ca contents were much lower in leaves showing tip-burn symptoms than in healthy leaves. Internal rot which is a tip-burn symptom occuring after head formation were noted in plants applied with high concentration of $NO_3{^-}-N$ both before and after the head formation stage. Ca contents correlated well with the rates of Ca application, but there was no correlation between ca conents and internal rot incidence. Chinese cabbage tip-burn is not caused by Ca deficiency, as is commonly believed, but rather by the water stress (95% water contents in $NO_3{^-}$-fed plants, 91% in $NH_4{^+}$-fed plants) resulting from root damage caused by ammonium toxicity. Internal rot is also caused by excess applications of nitrogen, and is unaffected by calcium levels.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.1
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• pp.39-44
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• 1980

To study the effects of sulfur dioxide on the plant; Barly, wheat, soybean sweet potato, cucumber, egg plant, red pepper, tomato, lettuce, water melon, castor bean, grape and lily were exposed to the different levels of sulfur dioxide gas(0.1, 0.25, 0.50, $1.0mg/{\ell}/hr$) The symptoms of damage, ratios of destroyed leaf, sulfur content and absorption amounts of the gas by leaves were investigated 1. According to the increasing concentration of the gas ratios of destroyed leaf were increased in all plants. The ratios of destroyed leaf were shown by egg plant at $0.1mg/{\ell}/hr$ of $SO_2$ were 30 percent, and no visible injuries were shown by the wheat potato, castor bean, water melon, lily at $0.25mg/{\ell}/hr$. 2. Gray and red brown spots between the vein nerve shown by barly and wheat leaf; leaf burn by soybean, potato, sweat potato, castor bean, egg plant, red pepper, tomato and grape; leaf withering from the leaf tips by the lettuce, water melon, lily. 3. The volums of the gas absorption by cucumber, egg plant, red peper, castor he an were more than $10{\ell}/hr$, however less than $2{\ell}/hr$, be lettuce, water melon, grape, barly and wheat. 4. According to the increasing concentration of sulfur dioxide gas, sulfur contents in leaf were increased in all plants, however volums of absorption gas were decreaed. 5. According to the increase of sulfur content in leaf, ratios of destroyed leaf were increased. 6. Positive correlation was shown between total and water soluble sulfur content in leaf.

• The Korean Journal of Air & Space Law and Policy
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• v.25 no.2
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• pp.43-77
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• 2010

The development of the aviation industry has exponentially increased the volume of passengers and cargo and gradually expanded the damage scope of all kinds of accidents in the process of transportation. As a result, the need for aviation insurance has accordingly grown bigger and bigger every day. That is why most nations have a law to force mandatory insurance on the aviation industry. However, the Montreal Convention of 1999, which Korea also signed and today has the most extensive effect in the international civil aviation community, offers no clear interpretations about the coverage of aviation insurance along with the Air Transport Business Promotion Act of Korea. The advanced nations of air transport business such as EU, the U. S. A. and Canada prescribe the coverage of aviation insurance and have a law that makes it mandatory for all the passengers and third parties to cover air carrier's liability. EU requires them to include cargo and baggage in scope of coverage, and the U. S. A. and Canada recommend insuring by having a shipper receive a written notice containing information about whether the concerned cargo is insured or not. Making the scope of coverage of aviation insurance clear by law serves several purposes including diversifying risks for air transport companies, providing the victims with enough protection, observing the international accountability required in the air transport industry, and promoting the productive and sustainable growth of the aviation industry. Thus problems with Korea's aviation insurance should be resolved by clearly stating the coverage of aviation insurance that the Korean air carriers and operators need to insure according to the current state of Korea's air transport by consulting the legislations of the advanced nations in air transports. and enacting a law to comprehensively govern Korea's aviation insurance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.739-744
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• 2003

This study was carried out to investigate the antioxidative activity and to identify the active components of hot-water extract of Paeoniajaponica (PJ), which was a main ingredient of a herb mixture preparation recently established as a potent candidate of radioprotector in our laboratory. The water extract was fractionated with CHCl$_3$, EtOAc and n-BuOH. The extract and its fractions showed very low activity in hydroxyl radical scavenging test. In lipid peroxidation test, the extract, EtOAc and water fractions showed moderate inhibition with the ratio above 50%. In DPPH radical scavenging test, the extract, EtOAc and water fraction showed high activity with the ratio above 80%, especially. EtOAc fraction scavenged the radicals as much as synthetic antioxidant (BHA), even at low concentration. It is suggested that mai or partition for antioxidative activity of Paeonia japonica was EtOAc fraction. Subsequently, two active compounds (PJE021-1 and JE024-1) from EtOAc fraction were isolated by using MCI gel and silica gel column chromatography The two compounds inhibited remarkedly the $H_2O$$_2$-induced DNA damage in human peripheral blood lymphocytes, measured by single-cell gel electrophoresis (SCGE). PJE021-1 protected the cells to almost negative control level, dose-dependently. PJE024-1 exhibited a potent inhibition with the ratio of 71% at even low concentration (0.5 $\mu\textrm{g}$/$m\ell$). Finally, their chemical structures were identified as gallic acid (PJE021-1) and (＋)-catechin (PJE024-1), respectively, on the basis of the speculation of spectral and physical data.