• Korean journal of applied entomology
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• v.42 no.4
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• pp.335-343
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• 2003

An experiment was conducted to investigate types of injury inflicted by the stone leek leafminer, Liriomyza chinensis Kato (Diptera: Agromyzidae) on welsh onion. A feeding scar made by an adult female was a hole round in shape, with diameter of 0.08 mm and 0.48 mm in lesion, resulting in a white spot, many of which often form vertical dotted lines on a leaf. Egg spots were oval with 0.1 ${\times}$0.14 mm in size, one or several of which often form a V-shape in group. Feeding by adults began immediately after emergence and was very active from 4th to 5th day. Oviposition was done from 2nd to 6th day after emergence. In both feeding and oviposition, they were more active in the day time. Larvae after emergence crawled up the leaf at first, and then moved up and down to feed on mesophyll. When in high density, they feed on leaf from leaf tip to bottom, and let the leaf die. Area of damage per one larva was calculated as 72.1 $\textrm{mm}^2$. The aged larvae escaped from the leaf in early morning, usually between 5 and 7 am. Most pupation sites were distributed near plants,5cm in soil depth and within 10 cm away from the plant. Pupae of L. chinensis overwintered 10cm below soil surface and emerged from early May to late June the next year Adults then moved to welsh onions near over wintering sites, nursery, transplanted, and levee.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.256-262
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• 2014

Cycle length of domestic nuclear power plants is determined by the demand-supply plan of utility company. The target cycle length is achieved by adjusting the number of feed fuel assembly and fuel enrichment. Traditionally, utility company first select the number of feed fuel assembly and then find out the fuel enrichment to achieve the special cycle length. But it is difficult to find out if this method is most economical than any other combinations of the enrichment and batch size satisfying the same cycle length. In this paper, core depletion calculation is performed to find out the optimum combination of the enrichment and batch size for given target cycle length in terms of fuel cycle cost using commercial core design code; CASMO/MASTER code. To minimize the uncertainty resulting from transition core analysis, levelized fuel cycle cost analysis was applied to the equilibrium cycle core in order to determine the optimum combination. The sensitivity study of discount rate was also carried out to analyze the levelized fuel cycle cost applicable to countries with different discount rates. From the levelized fuel cycle cost analysis results, the combination with smaller batch size and higher fuel enrichment becomes more economical as the discount rate becomes lower. On the other hand, the combination with higher batch size and lower fuel enrichment becomes more economical as the discount rate becomes higher.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.77-82
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• 2018

In South Korea, LM crops are not allowed to grow locally, but have been allowed to be imported as food and feed purposes. Currently, the typical LMO imports are continuously increasing in the region of South Korea. In 2014, we carried out a review of the environmental release monitoring of LM maize (Zea mays L.) in Gyeonggi-do of South Korea, and analyzed volunteer samples using strip test kits and polymerase chain reaction (PCR) methods. We thereby collected 44 volunteers of released LM maize in 169 locations around ports, from roadsides, feed factories and stockbreeding farmhouses. We found 4 positive samples at 3 sites using strip test kits. Based on the PCR analysis, the LM maize plants were found using event-specific primers. These results suggested that our monitoring is necessary to detect the presence of released LM maize in the natural environment of South Korea.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.44-52
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• 2002

Low temperature thermal desorption (LTTD) has become one of the cornerstone technologies used for the treatment of contaminated soils and sediments in the United States. LTTD technology was first used in the mid-1980s for soil treatment on sites managed under the Comprehensive Environmental Respones, Compensation and Liability Act (CERCLA) or Superfund. Implementation was facilitated by CERCLA regulations that require only that spplicable regulations shall be met thus avoiding the need for protracted and expensive permit applications for thermal treatment equipment. The initial equipment designs used typically came from technology transfer sources. Asphalt manufacturing plants were converted to direct-fired LTTD systems, and conventional calciners were adapted for use as indirect-fired LTTD systems. Other innovative designs included hot sand recycle technology (initially developed for synfuels production from tar sand and oil shale), recycle sweep gas, travelling belts and batch-charged vacuum chambers, among others. These systems were used to treat soil contaminated with total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs) and dioxin with varying degrees of success. Ultimately, performance and cost considerations established the suite of systems that are used for LTTD soil treatment applications today. This paper briefly reviews the develpoment of LTTD systems and summarizes the design, performance and cost characteristics of the equipment in use today. Designs reviewed include continuous feed direct-fired and indirect-fired equipment, batch feed systems and in-situ equipment. Performance is compared in terms of before-and-after contaminant levels in the soil and permissible emissions levels in the stack gas vented to the atmosphere. The review of air emissions standards includes a review of regulations in the U.S. and the European Union (EU). Key cost centers for the mobilization and operation of LTTD equipment are identified and compared for the different types of LTTD systems in use today. A work chart is provided for the selection of the optmum LTTD system for site-specific applications. LTTD technology continues to be a cornerstone technology for soil treatment in the U.S. and elsewhere. Examples of leading-edge LTTD technologies developed in the U.S. that are now being delivered locally in global projects are described.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.185-200
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• 2012

It has been reported that world population continues to increase so that a matter of food security can be a world-wide problem for mankind. An anticipated rise in world population of 30% and the subsequent increased demand for food brings with it challenges in terms of global resource usage and food security. However, ruminant livestock production and consumption make a large contribution to the greenhouse gas (GHG) emissions which can be attributable to food production. Given the association between GHG and climate change, this is clearly of great concern to the livestock industry worldwide. Nevertheless, ruminant livestock also play an important role in global food security as they can convert the plant cell wall materials and non-protein nitrogen compounds, found widely in plants but indigestible to all monogastric animals including man, into high value proteins for human consumption. Much effort has been made to maximize animal production, feed conversion ratio, and to improve animal breeding in ruminant agriculture. In addition improving feed formulation techniques, developing chemical additives, plant extracts, and new plant varieties for grazing have been tested. Future ruminant production systems will need to capitalize on important benefits of ruminants. It is therefore suggested that ruminant agriculture has a key role to play in maintaining and enhancing provision of quality proteins and essential nutrients for human being but the challenge of reducing GHG emissions, and methane in particular, needs to be successfully addressed.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.158-162
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• 2005

The objective of this study was to assess the assimilable organic carbon (AOC) in processing water, a measurement of biostability, at several stages of a full-scale nanofiltration (NF) water treatment plant. The NF membrane plant investigated was a $45,400\;m^3$/day (12 mgd) water softening facility at Plantation City in southern Florida, which utilized an organic rich groundwater (dissolved organic carbon (DOC) = 17.6 mg/L) originated from a surficial aquifer. The average AOC concentration of raw feed water was estimated at 158 g/L acetate-C. After pretreatment(acid and antiscalant addition), AOC levels increased by 12.7%, suggesting that pretreatment chemicals used to control scaling may deteriorate feed water biostability. The results also demonstrated that nanofiltration was capable of effectively removing 63.4% of AOC and 94.8% of DOC from the raw water. AOC rejection in stage 1 (${\approx}\;68%$) was slightly higher than that of stage 2 (${\approx}\;58%$) indicating that AOC was removed less at the solution environment (i.e. low pH, high ionic strength and high hardness), which was often created in the $2^{nd}$ stage of full-scale membrane plants due to pretreatment (acid addition) and high recovery operation.

• Journal of Environmental Science International
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• v.16 no.10
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• pp.1203-1208
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• 2007

Feathers are produced in huge quantities as a waste product at commercial poultry processing plants. Since feathers are almost pure keratin protein, feather wastes represent an alternative to more expensive dietary ingredients for animal feedstuffs. Generally they become feather meal used as animal feed after undergoing physical and chemical treatments. These processes require significant energy and also cause environmental pollutions. Therefore, biodegradation of feather by microorganisms represents an alternative method to prevent environment contamination. The aim of this study was to investigate cultural conditions affecting keratinolytic protease production by Bacillus pumilus RS7. We also assessed the nutritive value of microbial and alkaline feather hydrolysates, The composition of optimal medium for the keratinolytic protease was fructose 0.05%, yeast extract 0.3%, NaCl 0.05%, K2HPO4 0.03%, KH2PO4 0.04% and MgCl2 6H2O 0.01%, respectively. The optimal temperature and initial pH was $30^{\circ}C$ and 9.0, respectively. The keratinolytic protease production under optimal condition reached a maximum after 18 h of cultivation. Total amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $113.8\;{\mu}g/ml$ and $504.9\;{\mu}g/ml$, respectively. Essential amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $47.2\;{\mu}g/ml$ and $334.0\;{\mu}g/ml$, respectively. Thus, feather hydrolysates have the potential for utilization as an ingredient in animal feed.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.163-170
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• 2013

Selective catalytic reduction of $NO_x$ by $NH_3$ ($NH_3$-SCR) over $V_2O_5/TiO_2$-based catalysts is recently reported to be an anthropogenic emitter of $N_2O$ that is a global warming gas with a global warming potential of 310. Therefore, this review will get a touch on significance of some parameters regarding $N_2O$ formation in the $deNO_xing$ reaction for fossil fuels-fired power plants applications. The $N_2O$ production in $NH_3$-SCR reaction with such catalysts occurs via side reactions between $NO_x$ and $NH_3$ in addition to $NH_3$ oxidation, and the extent of these undesired reactions depends strongly on the loadings of $V_2O_5$ as a primary active component and the promoter as a secondary one ($WO_3$ and $MoO_3$) in the SCR catalysts, the feed and operating variables such as reaction temperature, $NO_2/NO_x$ ratio, oxygen concentration, gas hourly space velocity, water content and thermal excursion, and the physical and chemical histories of the catalysts on site. Although all these parameters are associated with the $N_2O$ formation in $deNO_xing$ reaction, details of some of them have been discussed and a better way of suppressing the $N_2O$ production in commercial SCR plants has been proposed.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.1-5
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• 1994

Sixteen kinds of piercing-sucking mouth type insects were observed at witches'-broom diseased paulownia (Paulownia tomentosa) trees. Among ten insect species tested, a leafhopper, Empoasca sp., transmitted paulownia witches'-broom mycoplasma-like organism(PWB-MLO) to periwinkle(Catharanthus roseus) plant. Adults of this leafhopper were collected from PWB-diseased paulownia trees. The leafhpoppers were allowed to feed on the PWB-infected paulownia trees for three weeks to acquire PWB-MLO. These insects were then transferred to healthy seedlings of paulownia and periwinkle plants for inoculation-feeding. About 30-40days after the inoculation, "little-leaf" symptoms developed on periwinkle plants, but no symptoms developed on paulownia seedlings. MLO infection in the diseased periwinkle tissue was diagnosed by fluorescence microscopy. MLOs were observed in the sieve tubes by electron microscopy, proving the insect transmission of PWB-MLO.