• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.403-413
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• 2008

This study was conducted to select excellent tank mix combinations of pesticides for aerial application by manned helicopter. Among 209 pesticide combinations of 3-way tank-mixing for aerial application, a total of 93 recommendable combinations including tricyclazole SC+validamycin-A SL+imidacloprid SL were finally selected for the simultaneous control of key pests on paddy rice such as blast, sheath blight, brown planthopper and moth. The selected combinations were not phytotoxic to rice plants and nearby non-target crops, and excellent in physicochemical properties of ultra low volume (ULV) spray solutions. The efficacies on sheath blight, brown planthoppers and white-backed planthoppers of pesticides sprayed by aerial application were similar to those of pesticides by conventional spraying. Total cost of aerial application in paddy rice was very economical as one fourth level of that of conventional spraying.

• Environmental Engineering Research
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• v.19 no.3
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• pp.269-274
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• 2014

On-site sanitation systems are typically installed to treat grey and toilet wastewaters in areas without sewer and centralized treatment systems. It is well known that, due to inappropriate design and operation, treatment performance of these systems in developing countries is not satisfactory in the removal of pathogens and organic matters. This research aimed to investigate the hydraulic conditions occurring in some on-site sanitation systems and the effects of hydraulic retention times (HRTs) on the system performance. The experiments were conducted with a laboratory-scale septic tank (40L in size) and an actual septic tank (600L in size), to test the hydraulic conditions by using tracer study with HRTs varying at 12, 24 and 48 hr. The experimental results showed the dispersion numbers to be in the range of 0.017-0.320 and the short-circuit ratios in the range of 0.014-0.031, indicating the reactors having a high level of sort-circuiting and approaching complete-mix conditions. The removal efficiency of $BOD_5$ was found to be 67% and the $k_{30}$ values for $BOD_5$ was $2.04day^{-1}$. A modified complete-mix model based on the relationship between $BOD_5$ removal efficiencies and HRTs was developed and validated with actual-scale septic tank data having a correlation coefficient ($R^2$) of 0.90. Therefore, to better protect our environment and minimizing health risks, new generation toilets should be developed that could minimize short-circuiting and improving treatment performance.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1229-1234
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• 2001

The bottom slab of Inchon LNG in-ground #213 tank is designed as a massive structure witch has a large depth and section. The purpose of this study is to determine the optimum mix design having good workability and low hydration heat for bottom slab concrete and to control the actual concrete quality in site. For this purpose, we select the optimum mix design used ternary blended cement(furnace slag cement＋fly ash) and design factors. As test results of actual application, we have finish placing the bottom slab concrete of 23,180㎥ during 68hours with good success and obtain the good quality of fresh and hardened concrete including slump, air contents, no-segregation, compressive strength and low hydration heat in actual data. All test results are satisfied with our specifications for bottom slab concrete and we cut costs as the use of ternary blended cement and the reduction of placing hours.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.463-468
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• 1999

The slurry wall of Inchon LNG receiving terminal tank will be planned the super flowing concrete having properties of high strength (required strength 520kg/$\textrm{cm}^2$), no-vibrating and massive structure in the underground. For the performance of this concrete, we investigate and select all materials, the optimum mix design and sensibility test in the laboratory. As test results, we choose portland blast-furnace slag cement and lime stone powder(L.S.P) as cementitious materials, W/C 41%(W/B 35.4%), S/a 50.8% and unit volume of coasre aggregate 0.30 as optimum mix design. Also test result of the fresh and hardened concrete are satisfied with specifications of slurry wall.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.135-138
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• 2003

The purpose of this study was to design the self-compaction concrete mixture, having not only high strength but also compensation of shrinkage without thermal crack under 4 sides outer restraint of the member. In the experimental mix, replacement ratio of limestone Powder, CSA expansive additives, and unit water were selected as parameters, using portland blast-furnace slag cement. And, bleeding test, expansibility test, hydration heat analysis were performed. As a results, when 35% of limestone Powder, 6% CSA expansive additives are replaced at unit water 175kg/$\textrm{m}^3$, demanded performances of fresh and hardened self-compaction concrete are accomplished.

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.85-88
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• 2004

The purpose of this study was to design the self-compaction concrete mixture, having not only high strength but also compensation of shrinkage without thermal crack under 4 sides outer restraint of the member. In the experimental mix, replacement ratio of limestone Powder, CSA expansive additives, and unit water were selected as parameters, using portland blast-furnace slag cement. And, bleeding test, expansibility test. hydration heat analysis were performed. As a results, when 35% of limestone Powder, 6% CSA expansive additives are replaced at unit water 175kg/$\textrm{m}^3$, demanded performances of fresh and hardened self-compaction concrete are accomplished.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.204-210
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• 1984

For weeding on the after-barley cropping soybean, the tank-mix use of postemergence herbicides acifluorfen and haloxyfop-methyl was tested. Acifluorfen has shown the transient leaf-burn on the newly formed soybean leaves, but no growth inhibitions. Under the treatment of acifluorfen only, grassy weeds occurred successively and explosively. However, under the combinated spraying of both herbicides, the grassy weeds could be controlled in a slight antagonistic, the broadleaved weeds in additive, and the total weed species including sedges in synergic tendencies, respectively. Also, to achieve the full-season weeding efficacies for the prominent crop yields, both herbicides are suggested to be mixed with more dosages than 0.245 kg ai/ha of acifluorfen and 0.15 kg ae/ha of haloxyfop-methyl, respectively.

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.14-18
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• 1993

Greenhouse study was undertaken to find tank-mix feasibility of quinclorac with molinate and propanil, selective post-emergence herbicides in controlling barnyardgrass, for reducing the application rate of quinclorac. Following foliar application in combination of quinclorac at 0.038, 0.075, 0.150, and 0.300kg ai/ha with molinate at 0.190, 0.380, 0.750 and 1.500kg ai/ha, and propanil at 0.263, 0.525, 1.050, and 2.100kg ai/ha at 3.5-leaf stage of barnyardgrass, fresh weight and weeding efficacy and their interaction by Colby's efficacy method were evaluated. Percent inhibition of barnyardgrass growth by quinclorac, molinate and propanil at recommended rate were 78.1, 26.1, and 61.7%, respectively. The dose combination shown above 85% in weeding efficacy were from 0.300kg of quinclorac with 0.75kg of molinate and 0.150kg of quinclorac with all rates of propanil. Therefore, combination of quinclorac with molinate tended to additive interaction and that of quinclorac with propanil appeared partially synergistic interaction. Conclusively, for reducing the application rate of quinclorac, the combination of quinclorac with propanil was more synergistic than that of quinclorac with molinate.

• KCI Concrete Journal
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• v.14 no.3
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• pp.121-129
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• 2002

This study investigates experimentally into the design factors and quality variations having an effect on the properties of the combined high flowing concrete to be poured in the slurry wall of Inchon LNG in-ground receiving terminal. Especially, high belite cement and lime stone powder as cementitious materials and viscosity agent in order to improve self-compaction and hydration heat are used in this study. Water-cement ratio(W/C), fine aggregate volume ratio(Sr) and coarse aggregate volume ratio(Gv) as design factors of the combined high flowing concrete are applied to determine the optimum mix design proportion. Also quality variations for sensitivity test are selected items as followings. (1)Surface moisture(5cases) and (2)Fineness modulus of fine aggregate(5cases), (3)Concrete temperature(3cases), (4)Specific surface(3cases) and particle size of lime stone powder. As experimental results, water-cement ratio, fine and coarse aggregate volume ratio are shown as the optimum range 51%, 43% and 53% separately considering site condition of slurry wall. Also quality factors by sensitivity test should be controlled in the following ranges. (1) Surface moisture :to.67% and (2)Fineness modulus 2.6$\pm$0.2 of fine aggregate, (3)Concrete temperature l0-20t, (4) Specific surface 6,000$\textrm{cm}^2$/g and particle size 9.7$\pm$1.0${\mu}{\textrm}{m}$ of lime stone powder. Based on the results of this study, the optimum mix design proportion of the combined high flowing concrete are selected and poured successfully in the slurry wall of LNG in-ground tank.

• Geomechanics and Engineering
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• v.8 no.1
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• pp.113-132
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• 2015

In this study, lime (L), silica fume (SF), and lime-silica fume (L-SF) mix have been used for stabilizing and considering their effects on the soft clay soil. The improvement technique adopted in this study includes improving the behaviour, of a square footing over soft clay through grouting the clay with a slurry of lime-silica fume before and after installation of the footing. A grey-colored densified silica fume is used. Three percentages are used for lime (2%, 4% and 6%) and three percentages are used for silica fume (2.5%, 5%, 10%) and the optimum percentage of silica fume is mixed with the percentages of lime. Several tests are made to investigate the soil behaviour after adding the limeand silica fume. For grouting the soft clay underneath and around the footing, a 60 ml needle was used as a liquid tank of the lime-silica fume mix. Slurried silica fume typically contains 40 to 60% silica fume by mass. Four categories were studied to stabilize soft clay before and after footing construction and for each category, the effectiveness of grouting was investigated; the effect of injection hole spacing and depth of grout was investigated too. It was found that when the soft clay underneath or around a footing is injected by a slurry of lime-silica fume, an increase in the bearing capacity in the range of (6.58-88)% is obtained. The footing bearing capacity increases with increase of depth of grouting holes around the footing area due to increase in L-SF grout. The grouting near the footing to a distance of 0.5 B is more effective than grouting at a distance of 1.0 B due to shape of shear failure of soft clay around the footing.