• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.401-410
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• 2005

A series of studies involving formulation processes, bubbling activity test, diffusibility test and biological efficacy test was undertaken to develop Jumbo herbicide formulations in paddy rice field. Gas evolution speed from the tablets prepared by different organic acids was in the order of oxalic acid, malonic acid, citric acid, and tartaric acid. The total volume of evolved gas from the tablet and diffusibility of the active ingredient in the submerged water were increased with increase of water temperature; the volume from 1 g of tablet at 10, 15, 25 and $30^{\circ}C$ for 5 minutes after immersion into water was 20, 25, 28, 45, 57 mL, respectively. The concentration of halosulfuron-methyl and pyriminobac-methyl in submerged water at 5, 15, 20 and $30^{\circ}C$ at the 2.4 m distance from the applied spot of the tablet was 20, 48, 85, and 97% of the concentration of treated spot, respectively. The evolved gas volume from the tablets was not affected by pH of submerged water. The concentration of halosulfuron-methyl in different sizes of submerged water within 24 hours after treatment of the tablet was maintained 0.16 ppm, which is ideal concentration at standard dosage regardless of the submerged water area. The concentration of pyriminobac-methyl was also uniformly dispersed in the water within 24 hours after applying it into the submerged water. The wind velocity of 5 m $sec^{-1}$ on concentration distribution of halosulfuron-methyl and pyriminobac-methyl in the submerged water 24 hours after treatment was not influenced; an equal concentration in the up the wind and down the wind from the applied spot was maintained. Spot treatments of one tablet formulations(5 g) including 4 times higher dosage at 4 different spots resulted in even concentration distribution of active ingredient in the water 24 hours after applying it into the submerged water.

• Journal of Industrial Technology
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• v.10
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• pp.69-72
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• 1990

In this paper the numerical method for the study of wave reflection from and transmission through submerged permeable breakwaters using the boundary element method is developed. The numerical analysis technique is based on the wave pressure function instead of velocity potential because it is difficult to define the velocity potential in the each region arising the energy dissipation. Also, the non-linear energy dissipation within the submerged porous structure is simulated by introducing the linear dissipation coefficient and the tag mass coefficient equivalent to the non-linear energy dissipation. For the validity of this analysis technique, the numerical results obtained by the present boundary element method are compared with those obtained by the other computation method. Good agreements are obtained and so the validity of the present numerical analysis technique is proved.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.129-135
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• 2009

PPCP (pharmaceuticals and personal care products) is known as micropollutant that is released from wastewater treatment plant. Research represents that these contaminants have increased in the last 10 years. This study tries to make four different trickling filter systems using plastic fiber media to remove PPCP such as acetaminophen, ibuprofen, caffeine. The results of the experiment that compares the process efficiencies of four different systems (A, B, C and D) using HBC media show that almost all the reactor has around 95% removal efficiency. Slope type HBC reactor has twice higher efficiency rather than submerged type reactor to remove PPCP in water system. In 8 hours, 89% of acetaminophen, ibuprofen, caffeine are removed in slope type reactor while 39% of them in submerged type.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.679-685
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• 1998

The Soysauce wastewater removal characteristics of submerged biofilters filled with two filter media respectively were experimentally examined with constant temperature, pH value and variable BOD loading and recirculation ratio. The decreasing order of BOD removal is Netring(random plastic media), cubic wire meshes(plastic module). This is mainly due to the media characteristics such as void ratio, specific surface area and media shapes. The BOD removal ratio decreases with increasing $BOD_5$/ volumetric loading rate, and the loading rate for the BOD removal over 85% is lower than 1.5kg$BOD_5$ 5/$m^3$d for the plastic media of Netring and cubic wire meshes. The $BOD_5$ removal rate increases with the recirculation ratio, but the rate of increase become smaller as the recirculation ratio increases over 20. When $BOD_5$ volumetric loading is 1.5kg$BOD_5$/$m^3$d, the required recirculation ratio to obtain 85% BOD$_{5}$ removal is about 20 for Netring and it was about 30 for cubic wire meshes.s.

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1095-1100
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• 2003

In this study, it was performed using submerged nonwoven bioreactor(SNBR) for removal of organic matter, nitrogen and phosphate under different aeration intervals(intermittent aeration). We applied the SNBR at the cheap nonwoven fiber module instead of the expensive membrane. The SUBR was mainly made up of an activated sludge reactor and a transverse flow nonwoven module, with an innovative configuration being in application between them. In case of sewage, the aeration conditions experimented consist of continuous aeration and 60min/60min, 120min/60min, 120min/120min of aeration/nonaeration time intervals, respectively. In case of landfill leachate, the intermittent aeration condition was 120min/120min at aeration/nonaeration. Consequently, a high COD removal rate (about 94%) was achieved in sewage and leachate. Although nutrient removal rate was relatively high without any additional chemicals.

• Journal of Industrial Technology
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• v.18
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• pp.209-216
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• 1998

Some mechanical properties of the submerged arc-welded(SAW) zone between different kinds of metal (SS400+SB450) are investigated and compared with that between same kinds of metal (SS400+SS400 and SB450+SB450). The analysis of the chemical components and observation of the micro-structure by SEM of the weld zone are also carried out. And the effect of the stress relief annealing is examined by comparing tensile strength, elongation, toughness add hardness of SAW specimens before and after the heat treatment.

• Korean Membrane Journal
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• v.7 no.1
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• pp.19-27
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• 2005

PP hollow fiber membrane was hydrophilized by EVOH dip coating followed by low temperature plasma treatment and UV irradiation. EVOH coating attained high water flux without any prewetting but its stability did not guaranteed at high water permeation rate. At high water permeation rate, water flux declined gradually due to swelling and delamination of the EVOH coating layer causing pore blocking effect. However, plasma treatment reduces the swelling, which suppress delamination of the EVOH coating layer from PP support result in relieving the flux decline. Also, UV irradiation helped the crosslinking of the EVOH coating layer to enhance the performance at low water permeation rate. FT-IR and ESCA analyses reveal that EVOH dip coating performed homogeneously through not only membrane surface but also matrix. Thermogram of EVOH film modified plasma treatment and W irradiation show that crosslinking density of EVOH layer increased. Chemical modification by plasma treatment and UV irradiation stabilized the hydrophilic coating layer to increase the critical flux of the submerged membrane.

• The Journal of the Korean dental association
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• v.58 no.8
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• pp.486-494
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• 2020

Objectives: Management of a horizontal root fracture of an anterior teeth is challenging and often requires multiple approaches for improving the functional and esthetic outcomes. This case report describes the treatment and 2-yr follow up of 3 maxillary incisors with horizontal root fracture. Two maxillary central incisors were treated with Mineral Trioxide Aggregate (ProRoot MTA, Dentsply, Tulsa, OK, USA). Left maxillary lateral incisors were treated with endodontic treatment and submerged. During 2-yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing even after endodontic treatment.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.51-61
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• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2125-2134
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• 2000

This research was to develope the economical treatment processes of the landfill leachate to meet the legal discharge standards. To achieve this purpose, experiments were conducted in laboratory to choose the optimum process and to obtain the design factors before a pi!ot-scale test. The concept of the process developing in this research was using the reverse osmosis system. The submerged membrane bio-reactor was used to achieve pre-treatment of reverse osmosis system and the concentrate was treated by evaporator with land fill gas as a fuel. The results of the research showed that SS, $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$ and T-N were removed 99.0%, 43.0%, 12.9%, 48.5% and 18.7% respectively in the submerged membrane bio-reactor. The reverse osmosis system could remove $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$ and T-N as an efficiency of97.5%, 97.6%, 79.7% and 85.4% respectively. The evaporator could remove $COD_{cr}$, $NH_4{^+}-N$ and T-N as an efficiency of 90.5%, 50.6% and 63.3% respectively. However the condensed water of the evaporator was not satisfied the legal standard and should be treated in reverse osmosis with the pre-treated leachate.