• Korean journal of applied entomology
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• v.9 no.1
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• pp.25-32
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• 1970

This experiment was conducted to find out the simultaneous control effect of granulated insecticides on the several major rice insect pests in Korea. The granulated insecticides used were Terracur P$5\%$ (one of the phosphoric insecticides), Lebaycid $5\%$, and Sang-gamma (gamma-BHC) $6\%$. Those insecticides were broadcasted by hand on the paddy field at the ratio of 3kg. in June and 4kg. in August per 10 a, and the date of insecticidal application was based on the maximum moth occurrence of the rice stem borer in 1969. The rice insect pests tested in this study were rice stem borer (Chilo suppressalis W.), green rice leafhopper (Nephotettix bipunctatus cincticeps U.), smiller brown planthopper (Laodelphax striatellus F.), and white back planthopper (Sogotella furcifera H.). For the study of residual effectiveness of the insecticides, the rice stem borer larvae just hatched from the eggs were installed on the sheath of rice plants collected from the paddy field after insecticidal treatment, and the mortality was made at 48 hours after installation. High mortality was observed in Terracur P and Sang-gamma treatments and low mortality in Lebaycid treatment. The duration of residual effects giving about 50% mortality was about 14 days in Sang-gamma and about 6 days in Terracur P treatments. The study on the effectiveness of the insecticides to the rice stem borer in the paddy field was made by the number of dead blades and white heads of the rice plants injured by the larvae, and the number of survival larvae in the straws after crop harvest. The order of insecticidal effectiveness to the rice stem borer was Terracur P=Sang-gamm>Lebaycid. The study on the effectiveness of the insecticides to the leafhoppers and planthoppers in the paddy field was made by the population density by sweeping (5 times) at the given day intervals after treatments. Terracur P was highly effective for the control of the green rice leafhoppers and Lebaycid was moderately effective, but Sang-gamma seemed not to be effective. The effectiveness of the insecticides tested to the planthoppers was not clear, and it seemed to related with the low insect population density. Study on the determination of proper timing of insecticidal application was not also made clear, and it seemed to be short in the range of day intervals in the insecticidal application. For the study on the control effects of the rice insect pests, rice yield per 100 hills per plot was observed. There was no statistically significant difference among the treatments in rice yields, but the order of yield (Terracur P>Sang-gamma>Lebaycid>Control) was paralleled with the tends of control effects above mentioned. In a view point of simultaneous control of the rice stem borers and green rice leafhoppers by the application of granulated insecticides, Terracur P and Lebaycid were more effective than Sang-gamma which have been used.

• Food Science and Preservation
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• v.20 no.6
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• pp.791-797
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• 2013

This study was conducted to investigate the changes in the composition and microbiological properties of domestic sun-dried salt (white and gray salts) according to their collection time and production method. The results showed that the moisture contents of the white and gray sun-dried salts were 10.4~13.2% and 5.2~8.0%, respectively, and the sand contents were 0.1% and 0.2~0.3%, respectively, according to the month. Several samples exceeded the criteria of 15% moisture content and 0.2% sand content. The ash content and salinity of gray salt (below 85% and 90%, respectively) were higher than those of white salt (both below 80%). The total chloride contents of the salts collected in September and October were slightly lower than that of the others and exceeded the criteria of above 40%. In the case of mineral contents, there was no significant difference among the collection times because the analyses showed a marked deviation. The microbiological analysis showed that there was no significant difference among the production method, but the salt samples collected in September and October had relatively high detection rates of total aerobe, staphylococci, and halophilic bacteria.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.60-65
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• 2014

This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.113-125
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• 1984

Water supply has been mainly dependent on the construction of the dams in Korea. It is difficult, however, to continue to construct dams for many reasons, such as the decrease of construction sites, the increase of construction costs, the compensation of residents in flooded areas, and the environmental effects. Water demands have increased and are expected to continue increasing due to the concentration of people in the cities, the rise of the living standard, and rapid industrial growth. It is acutely important to find countermeasures such as development of ground water, desalination, and recycling of waste water to cope with increasing water demands. Recycling waste water includes all means of supplying non-potable water for their respective usages with proper water quality which is not the same quality as potable water. The usages of the recycled water include toilet flushing, air conditioning, car washing, yard watering, road cleaning, park sprinkling, and fire fighting, etc. Raw water for recycling is obtained from drainage water from buildings, toilets, and cooling towers, treated waste water, polluted rivers, ground water, reinfall, etc. The water quantity must be considered as well as its quality in selecting raw water for the recycling. The types of recycling may be classified roughly into closed recycle systems and open recycle systems, which can be further subdivided into individual recycle systems, regional recycle systems and large scale recycle system. The treatment methods of wastewater combine biochemical and physiochemical methods. The former includes activated sludge treatment, bio-disc treatment, and contact aeration treatment, and the latter contains sedimentation, sand filtration, activated carbon adsorption, ozone treatment, chlorination, and membrane filter. The recycling patterns in other countries were investigated and the effects of the recycling were divided into direct and indirect effects. The problems of water reuse in recycle patterns were also studied. The problems include technological, sanitary, and operational problems as well as cost and legislative ones. The duties of installation and administrative organization, structural standards for reuse of water, maintenance and financial disposal were also studied.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.416-422
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• 2004

Efficacy of surface sterilization and physicochemical properties of electrolyzed water manufactured depending on electrolyte, materials, and type of electrolytic diaphragm used were investigated. Physical properties of electrolyzed water manufactured from diaphragm system showed the highest effectiveness under at distance between diaphragms of 1.0 mm and 20% NaCl supplying rate of 6 mL/min. ORP, HClO (should defined) content, and pH at above conditions were 1,170 mV, 100 ppm, and 2.5, respectively. Two-stage electrolyzed system was more effective than one-stage one. Electrolyzed water manufactured from non-diaphragm system at 4 mL/min supplying rate of 20% NaCl was similar to the most effective diaphragm system, whereas ORP, HClO content, and pH were 800 mV, 200 ppm, and 9, respectively. Sealed electrolyzed water could be preserved more than one month at room temperature with ORPs of 750 and 1,150 mV in non-diaphragm and diaphragm systems, respectively, and at HClO content of 100 ppm. Physicochemical properties of electrolyzed water manufactured from electrolytic diaphragm of $IrO_{2}$ and Pt+Ir were more effective than that of Pt. ORP and HClO contents of electrolyzed water manufactured from various electrolytes were high in order of NaCl>KCl>$CaCl_{2}$, whereas no differences were observed among electrolytes in sterilization efficacy. Twelve kinds of microorganisms tested (initial total count, $10^{5}-10^{6}CFU/mL$) were sterilized within 1-2 min by electrolyzed water.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.105-114
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• 2007

The most advanced oxidation processes (AOPs) are based on reactivity of strong and non-selective oxidants such as hydroxyl radical (${\cdot}OH$). Decomposition of typical DNAPL chlorinated compounds (TCE, PCE) using various advanced oxidation processes ($UV/Fe^{3+}$-chelating agent/$H_2O_2$ process, $UV/H_2O_2$ process) was approached to develop appropriate methods treating chlorinated compound (TCE, PCE) for further field application. $UV/H_2O_2$ oxidation system was most efficient for degrading TCE and PCE at neutral pH and the system could remove 99.92% of TCE after 150 min reaction time at pH 6($[H_2O_2]$ = 147 mM, UVdose = 17.4 kwh/L) and degrade 99.99% of PCE within 120 min ($[H_2O_2]$ = 29.4 mM, UVdose = 52.2 kwh/L). Whereas, $UV/Fe^{3+}$-chelating agent/$H_2O_2$ system removed TCE and PCE ca. > 90% (UVdose = 34.8 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 147 mM) and 98% after 6hrs (UVdose = 17.4 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 29.4 mM), respectively. We improved the reproduction system with addition of UV light to modified Fenton reaction by increasing reduction rate of $Fe^{3+}$ to $Fe^{2+}$. We expect that the system save the treatment time and improve the removal efficiencies. Moreover, we expect the activity of low molecular organic compounds such as acetate or oxalate be effective for maintaining pH condition as neutral. This oxidation system could be an economical, environmental friendly, and practical treatment process since the organic compounds and iron minerals exist in nature soil conditions.

• Korean Journal of Environment and Ecology
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• v.22 no.1
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• pp.18-34
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• 2008

Based on external morphology, each of five species can be classified into three groups: 1) B. falcatum group (B. falcatum, B. scorzonerifolium), 2) B. euphorbioides group (B. euphorbioides) and 3) B. longiradiatum group (B. longiradiatum, B. latissimum). B. falcatum group has cauline leaves linear or lanceolate in shape and attenuate at base and not surrounding the stem. In contrast, B. longiradiatum group and B. euphorbioides group have cauline leaves ovate, lanceolate or panduriform in shape and auriculate or cordate at base and completely surrounding the stem. The inflorescence is basically compound umbels terminated at the apex of stem. But B. euphorbioides group is small in size and pedicels are rather short and the number of the pedicel is ca. 20. On the other hand, B. longiradiatum and B. falcatum groups are large in size and their pedicels are long and the number of the pedicel is around 10. The pore of pollen aperture of B. longiradiatum and B. latissimum is partially projected or not while those of B. falcatum group and B. euphorbioides is usually remarkably projected. The number of somatic chromosomes was counted as 2n=20 in B. falcatum, 2n=12 in B. scorzonerifolium and B. longiradiatum, and 2n=16 in B. euphorbioides and B. latissimum. Although chromosome numbers of B. euphorbioides and B. latissimum are the same, the two species are not likely to relate because the karyotypes of the two species are different from each other. Based on these observations, it can be concluded that B. latissimum is most closely related to B. longiradiatum. However, molecular data indicated that the species is probably related to B. bicaule distributed in central Siberia. In terms of conservation of B. latissimum, overexploitation by human and grazing by goat are most threatened factors.

• Korean Journal of Environmental Agriculture
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• v.7 no.1
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• pp.8-13
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• 1988

This experiment was conducted to evaluate the effect of polyethylene film(P.E.) mulching on degradation of the soil insecticides, endosulfan(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), fonofos(O-ethyl S-phenyl ethylphosphonodithioate), and ethorprophos(O-ethyl S, S-dipropyl phosphorodithioate) in red pepper, peanut, and sesame fields. Degradation of endosulfan, fonofos and ethoprophos in the soils under P.E. mulching and non-mulching followed first-order kinetics. The half-lives of fonofos, ethoprophos, ${\alpha}-$ and ${\beta}-endosulfan$ were $19{\sim}21$, $25{\sim}37$, $33{\sim}39$ and $56{\sim}81$ days, respectively. There were few differences in the half-lives of fonofos in either mulching or non-mulching concitions. However, half-lives of α-endosulfan, ethoprophos, and ${\beta}-endosulfan$ were 6, 12 and 25 days longer under P.E. mulching than under non-mulching conditions, respectively. The effect of P.E. mulching on degradation was remarkable for the slower degrading insecticides. Residues of ethoprophos in the harvested sesame under P.E. mulching and non-mulching conditions were 0.024 and 0.074ppm, respectively. Residues of fonofos in the harvested peanuts under P.E. mulching and non-mulching conditions were 0.078 and 0.017ppm, respectively. However, no endosulfan was detected in the harvested red peppers under either condition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.1-8
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• 2019

This study was conducted to predict the energy requirements for maintenance and growth of female Korean black goats during their growth and pregnancy phases. Fifty female goats ($18.7{\pm}0.27kg$) in their growth phase with an average age of 5 months were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in metabolic energy (ME) [2.32 (G1), 2.49 (G2), 2.74 (G3), 2.99 (G4), and 3.24 (G5) Mcal/kg] until they were 9-month-old. After natural breeding, 50 female goats ($30.7{\pm}0.59kg$) were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in ME [2.32 (P1), 2.43 (P2), 2.55 (P3), 2.66 (P4), and 2.78 (P5) Mcal/kg]. The average feed intake ranged between 1.5 and 2.0% of the body weight (BW), and there was no significant difference between the treatment groups with goats in growth or pregnancy phases. Average daily gain (ADG) in diet demand during the growth phase increased with an increasing ME density and ranged from 46 to 69 g/d (p<0.01). Feed conversion ratio (FCR) improved with the ME density during the growth phase (p<0.01). The intercept of the regression equation between ME intake and ADG indicated that energy requirement for maintenance of goats during growth and pregnancy phases was $103.53kcal/BW^{0.75}$ and $102.7kcal/BW^{0.75}$, respectively. These results may serve as a basis for the establishment of goat feeding standards in Korea. Further studies are required to assess the nutrient requirement of goats using various methods for improving accuracy.