• Journal of Aquaculture
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• v.20 no.1
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• pp.31-40
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• 2007

To find out the effect of the spat planting time and environmental factors in the arkshell, Scapharca broughtonii (Schrenck), we investigated the growth, survival rate of arkshell and habitat characteristics in Gamak Bay, Yeoja Bay and Saryang Island. We planted artificial spats of arkshell in Gamak Bay and Yeoja Bay at November 2004, and also planted domestic and Chinese natural spats in Saryang Island at March 2005. We measured growth, survival rate of arkshell, physiochemical parameters of the water mass (water temperature, salinity, dissolved oxygen, nutrients and chlorophyll a) and characteristics of the sediment (oxygen penetration depth, oxygen microprofiles, ignition loss and chemical oxygen demand) by monthly. The cumulative survival ratio of arkshell in Gamak Bay was the highest at December, whereas the ratio of arkshell in Yeoja Bay was recorded as 0% at October. The monthly growth rates of arkshell length in Gamak Bay and Yeoja Bay were the highest in May and the growth rate of the Korean arkshell in Saryang Island was higher than Chinese ones significantly. The high mortality (> 65%) of the arkshell in Yeoja Bay during summer probably caused by high water temperature, inflow of low salinity water, and low dissolved oxygen concentration in sediment. The concentrations of nutrient and sediment COD were considered to play an important role in the monthly survival ratio of arkshell in Gamak Bay and Sarayng Island. We suggest that the growth and mortality of arkshell might be influenced to the planting time of spat and the habitat characteristics.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.84-93
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• 2010

Petri dish and pot experiments were conducted to investigate germination and seedling emergence of Ammannia coccinea as influenced by environmental factors. The best germination of A. coccinea was obtained at $35/30^{\circ}C$ of temperature and 0 bar of osmotic potential, while no germination at temperatures of ${\leq}$ $15^{\circ}C$ and ${\geq}$ $40^{\circ}C$, osmotic potentials of ${\leq}$ -2.0 bar, or dark condition. The best seedling emergence was observed at $35/30^{\circ}C$, at which the first emergence of A. coccinea was observed at 7 days after sowing (DAS) with its maximum emergence reached at 10 DAS. No seedling emergence was observed at $15/10^{\circ}C$ with significant reduction at $40/35^{\circ}C$. Seedling emergence decreased with increasing soil depth, resulting in no seedling emergence at ${\geq}$ 3 cm. The Gompertz model well described the cumulative germination and seedling emergence of A. coccinea with time. Germination influenced by osmotic potential and seedling emergence influenced by soil burial depth were well described by the logistic model. Overall results indicate that A. coccinea is photoblastic and requires temperatures greater than $15^{\circ}C$, osmotic potential greater than -2.0 bar, and soil burial depth shallower than 3 cm for its germination and seedling emergence, which were faster than M. vaginalis but slower than E. crus-galli.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.3
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• pp.207-218
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• 2017

In this study, pitch-based activated carbon fibers (ACFs) were modified with pyrolysis fuel oil (PFO). Carbonized ACF samples were activated at $850^{\circ}C$, $880^{\circ}C$ and $900^{\circ}C$. A scanning electron microscope (SEM) and a BET surface area apparatus were employed to evaluate the indoor radon removal of each sample. Among three samples, the BET surface area and micropore area of ACF880 recorded the highest value with $1,420m^2{\cdot}g^{-1}$ and $1,270m^2{\cdot}g^{-1}$. Moreover, ACF880 had the lowest external surface area and BJH adsorption cumulative surface area of pores with $151m^2{\cdot}g^{-1}$ and $35.5m^2{\cdot}g^{-1}$. This indicates that satisfactory surface area depends on the appropriate temperature. With the above scope, ACF880 also achieved the highest radon absorption rate and speed in comparison to other samples. Therefore, we suggest that the optimum activation temperature for PFO containing ACFs is $880^{\circ}C$ for effective indoor radon adsorption.

• Korean journal of applied entomology
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• v.18 no.3 s.40
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• pp.127-132
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• 1979

This experiments were performed to investigate the temperature effects, which caused by the various types of collecting trap treatments, during the overwintering period of pine gall midge larvae, on the peak adult emergence time. And the following results were obtained. 1) The maximum temperatures inside of the collection traps were significantly different each other, and the vinyl cage showed the highest degree which highering $15^{\circ}C$, and standard cage, cage-50 and funnel trap highering $3-12^{\circ}C$ in monthly average comparing to control. 2) There was no significant difference among the treatment in minimum temperatures, during the overwintering periods of larvae. 9) The peak adult emergence time were May 15 in vinyl cage plot which shortened 20 days and both standard cage and cage-50 shortened 14 day than that of control. 4) The funnel type trap treatment delayed 6 days of the peak adult emergence comparing to control, in spite of the treatment showing higher maximum and cumulative temperatures than the control plot. 5) The decadal maximum temperatures of middle part of December and March were significantly correlated with the shortening of the peak adult emergence date.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.112-118
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• 2006

To select efficient entomopathogenic fungal strains of Lecanicillium for the biocontrol of aphid, Myzus persicae, conidial suspension ($1{\times}10\;conidia/ml$) was sprayed onto a detached Chinese cabbage leaf in a petri dish with a dampened filter paper that had 20 nymphs of aphid. Lecancillium strain 4078 and 6543 were the best strains for the biocontrol of aphid at high temperature of $30^{\circ}C$ and low relative humidity (RH) of 85%, respectively. The cumulative mortality of strain 4078 at $30^{\circ}C$ after 3 days was 100% and that of strain 6543 was 90% at 85% RH after 5 days. Strain 4078 also exhibited almost 100% germination ratio of conidia and high rate of mycelial growth at the broad temperature-range of $15{\sim}25^{\circ}C$. The strain 4078 and 6543 were all identified as Lecanicillium species based on the DNA sequences (accession no.: EF026004 and EF026005, respectively) of the ITS regions of the fungi. Excellent production of aerial conidia of strain 6543 was accomplished by using steamed polished rice as the solid culture medium.

• Journal of fish pathology
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• v.25 no.3
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• pp.151-158
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• 2012

Diseased eel (Anguilla bicolor) displayed severe hemorrhages in the gills, and congestion and swelling in the liver. During the epizootic, the water temperature was $28^{\circ}C$ and the morality rates were about 5%. No parasites were found on the gills and skin. Bacteria were not cultured from any internal organs using TSA or SS agar at $28^{\circ}C$ for 48 hrs. Histopathologically, the gills showed epithelial hyperplasia in the base of secondary gill lamellae and hemorrhages in the capillaries. Some cells in the proliferated interlamellar epithelia exhibited marginal hyperchromatosis. And severe vacuolated changes in the parenchymal cells and congestion in the central veins were observed in the liver. The specific amplicon (396 bp) was detected from gills and opercula of affected eel PCR using Anguillid herpesvirus-1 (AngHV-1) -specific primer sets HVAPOLVPSD (5-'GTG TCG GGC TTT GTG GTG C-3') and HVAPOLOOSN (5'-CAT GCC GGG AGT CTT TTT GAT-3'). Sequencing analysis of the amplicon demonstrated that this gene was 99% homologous to the AngHV-1 sequence deposited in GenBank. This is the first report of AngHV-1 outbreak in the farmed shortfin eels (A. bicolor) in Korea. When diseased fish were maintained for 10 days at water temperatures of $32^{\circ}C$ and $35^{\circ}C$, the cumulative mortalities were 100% and 10%, respectively. Even though the AngHV-1 genome in the gills from the eel kept at $35^{\circ}C$ was detected using PCR, the structure of gill filaments was similar with that of normal fish. Increasing the water temperature to $35^{\circ}C$ was an effective way to diminish the mortality of AngHV-1 affected eel.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.77-82
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• 2007

Volatilization of ammonia from N fertilizer is the major mechanism of N losses that occur naturally in all soils and is influenced by numerous soils, environmental and N fertilizer management factors. Vegetables are often damaged by $NH_3$ gas volatilized from the high rates of N fertilizer. We determined the rate of $NH_3$ volatilization from urea applied to surface of the alluvial soil (coarse silty, mixed, mesic family of Dystric Fluventic Eutrochrepts, Ihyeon series) as affected by fertilizer management factors such as rate of urea application, irrigation schedule and temperature. The $NH_3$ volatilization was triggered about 3 d after urea application and reached at maximum level in general within 15 days. Cumulative amounts of 3.0, 4.4, and 8.0 kg of $NH_3$ N after 17 d were volatilized at application rates of 200, 400, and $600kg\;N\;ha^{-1}$, respectively, which were equivalent to the N losses of 15.0, 10.9, and 13.0% of N applied. Masses of N volatilization were 5, 21, 75 and $87kg\;NH_3\;N\;ha^{-1}$ at 5, 8, 22, and 28, respectively. Total amounts of 21.3, 21.2, and $16.6kg\;N\;ha^{-1}$ were volatilized at control, 5 and 10 mm water irrigation before fertilization, respectively. However, those at 5 mm irrigation after fertilization were only $10.44kg\;N\;ha^{-1}$. Results showed that urea loss can be avoided by incorporating with the recommended level, applying when temperatures are low or irrigating immediately to carry the urea into soil.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.66-73
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• 2011

Objective of this study was to investigate the effect of biogas production to different systems and feeding stocks. For the biogas production through operating the temperature phase anaerobic digestion(TPAD) with different feeding stocks, the stage state of biogas production with 70% of methane concentration in the thermophilic digestion tank with co-digestion of food waste and swine manure(40 : 60) was delayed at 3.5 times, but its mesophilic tank was short for 5 days as relative to the swine manure. The cumulative methane production in the thermophilic digestion tank with co-digestion of food waste and swine manure was started with greater than its swine manure at 60 days after digestion periods. However, its mesophilic tank with swine manure was great at 3 days after digestion periods. For aspect of anaerobic digestion processes with swine manure, it was appeared that the stage state of biogas production rate in TPAD was shorter than the two phase anaerobic digestion system.

• Korean Journal of Optics and Photonics
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• v.30 no.2
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• pp.37-47
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• 2019

A reflecting omnidirectional optical system with four spherical and aspherical mirrors, for use with long-wavelength infrared light (LWIR) for night surveillance, is proposed. It is designed to include a collecting pseudo-Cassegrain reflector and an imaging inverse pseudo-Cassegrain reflector, and the design process and performance analysis is reported in detail. The half-field of view (HFOV) and F-number of this optical system are $40-110^{\circ}$ and 1.56, respectively. To use the LWIR imaging, the size of the image must be similar to that of the microbolometer sensor for LWIR. As a result, the size of the image must be $5.9mm{\times}5.9mm$ if possible. The image size ratio for an HFOV range of $40^{\circ}$ to $110^{\circ}$ after optimizing the design is 48.86%. At a spatial frequency of 20 lp/mm when the HFOV is $110^{\circ}$, the modulation transfer function (MTF) for LWIR is 0.381. Additionally, the cumulative probability of tolerance for the LWIR at a spatial frequency of 20 lp/mm is 99.75%. As a result of athermalization analysis in the temperature range of $-32^{\circ}C$ to $+55^{\circ}C$, we find that the secondary mirror of the inverse pseudo-Cassegrain reflector can function as a compensator, to alleviate MTF degradation with rising temperature.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.287-298
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• 2020

It is predicted that future climate warming will occur, and the subtropical climate zone currently confined to the south coast of Korea will gradually rise north. The shift of climate zone implies a change in area for cultivating crops. This study aimed to evaluate the current and future status of climate zones based on the high-resolution climate data of South Korea to prepare adaptation measures for cultivating crops under changing agricultural climate conditions. First, the climatic maps of South and North Korea were produced by using the high-resolution monthly maximum and minimum daily temperature and monthly cumulative precipitation produced during the past 30 years (1981-2010) covering South and North Korea. Then the climate zones of the Korean Peninsula were classified based on the Köppen climate classification. Second, the changes in climate zones were predicted by using the corrected monthly climate data of the Korean Peninsula (grid resolution 30-270m) based on the RCP8.5 scenario of the Korea Meteorological Administration. Köppen climate classification was applied based on the RCP8.5 scenario, the temperature and precipitation of the Korean Peninsula would continue to increase and the climate would become simpler. It was predicted that the temperate climate, appearing in the southern region of Korea, would be gradually expanded and the most of the Korean Peninsula, excluding some areas of Hamgkyeong and Pyeongan provinces in North Korea, would be classified as a temperate climate zone between 2071 and 2100. The subarctic climate would retreat to the north and the Korean Peninsula would become warmer and wetter in general.