• Title/Summary/Keyword: L/D rate

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Stereoselective Solvolyses of Activated Esters in the Aggregate System of Imidazole-Containing Copolymeric Surfactants

  • Cho, I-Whan;Lee, Burm-Jong
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.172-177
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    • 1989
  • Stereoselective solvolyses of optically active activated esters in the aggregate system of optically active polymeric surfactants containing imidazole and benzene moieties were performed. The catalyst polymers employed were copolymers of N-methacryloyl-L-histidine methyl ester (MHis) with N,N-dimethyl-N-hexadecyl-N-[10-(p-methacryloylo xyphenoxycarbonyl)-decyl]ammonium bromide(DEMAB). In the solvolyses of N-carbobenzoxy-D- and L-phenylalanine p-nitrophenyl esters (D-NBP and L-NBP) by polymeric catalysts, copoly(MHis-DEMAB) exhibited not only increased catalytic activity but also enhanced enantioselectivity as the mole ${\%}$ of surfactant monomers in the copolymers increased. The polymeric catalysts showed noticeable enantioselective solvolyses toward D- and L-NBP of the substrates employed. As the reaction temperature was lowered for the solvolyses of D- and L-NBP with the catalyst polymer containing 3.5 mole ${\%}$ of MHis, the increased reaction rate and enhanced enantioselectivity were observed. The coaggregative systems of the polymer and monomeric surfactants were also investigated. In the case of coaggregate system consisted of 70 mole ${\%}$ of cetyldimethylethylammonium bromide with polymeric catalyst showed maximum enantioselective catalysis, viz., $k_{cat}(L)/k_{cat}(D)$ = 2.85. The catalyst polymers in the sonicated solvolytic solutions were confirmed to form large aggregate structure by electron microscopic observation.

Efficiency of Livestock Farming Wastewater Treatment by Trickling Filters (撒水濾床法에 依한 畜産廢水의 處理效果에 관한 연구)

  • Ahu, Soo Mi
    • Journal of Environmental Health Sciences
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    • v.11 no.2
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    • pp.17-27
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    • 1985
  • The objectives of this study is to examine efficiency of swinery wastewater treatment by trickling filters' pilot plant. The results of this study are as follows: 1. The characteristics of sample. The BOD$_5$ was from 2,450 to 2,880mg/l, COD(KMnO$_4$ acid method) was from 910 to 1,064mg/l, and SS was from 920 to 990mg/l. The pH of influent was from 7.3 to 7.6, and the temperature of water was from 17.0$\circ$C to 22.5$\circ$C. 2. For experiment by recirculation, the BODs removal efficiency is 65.2% at recirculation ratio (r)=0, and 70.7% at r=1. The ramoval efficiency of this study is higher than NRC formula of U.S.A.. The recirculation is not significant effect on removal efficiency. 3. For experiment by hydraulic load, the BOD$_5$ removal rate decreased from 73.1% at $3.1m^3/m^2\cdot d$ to 65.3% at $9.2m^3/m^2\cdot d$. The design formula of this study which shows the removal rate of soluble BOD is $Le/Li =10^{-0.24} D/Q^{0.24}$ (Q: hydraulic load, D: depth of filter). 4. For experiment by organic load, the BOD$_5$ removal rate is increased from 70.2% at $0.77kg/m^3\cdot d$ to 75.4% at $4.28kg/m^3\cdot d$. We can obtain the straight line y=0.749 x (y: removed BOD, x :applied BOD) by the least squares method. 5. We can know that trickling filters is strong with the hydraulic load and the organic matter shock load. Here, we can judge that trickling filters is a good method for the treatment of swinery wastewater which containing high concentrated organic matter.

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Development of Biological Filtration Process for Effective Nitrogen Removal in Tertiary Treatment of Sewage (생물막 여과반응기를 이용한 고도질소 제거법의 개발)

  • Jeong, Jin-Woo;Kim, Sung-Won;Tsuno, Hiroshi
    • Journal of Korean Society on Water Environment
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    • v.22 no.2
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    • pp.222-229
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    • 2006
  • The treatment performance and operational parameters of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. In Filter 2, denitrification was accomplished under LV of 50~168 m/d in a 1 m filter-bed. However, the denitrification capacity reached the maximum when the linear velocity was increased to 202 m/d. Relationship between increase in microorganism and headloss was clearer in Filter 2. As a result, the denitrification rate increased from 1.0~2.3 kgN/($m^3-filter-bed{\cdot}d$) as the headloss increased. The COD removal rate was 6.0~9.6 kgCOD/($m^3-filter-bed{\cdot}d$) when operated with Filters 1 and 2. These results mean that captured bacteria contributed a part of COD consumption and denitrification. The maximum nitrification and denitrification rate was 0.5 and 4 kgN/($m^3-filter-bed{\cdot}d$) in Filter 1 and 2.The ratio of backwashing water to the treated water was about 5~10 %. In Filter 1, wasted sludge in backwashing was only 0.7~5.3 gSS/($m^3$-treated water). In Filter 2, added methanol was converted into sludge and its value was 8.0~24 gSS/($m^3$-treated water). These results proved that this process is both convenient to install as tertiary treatment and cost effective to build and operate.

Enhancing Anaerobic Digestion of Furfural Wastewater through Magnetite Powder Supplementation (자철석 가루 투입을 통한 푸르푸랄의 혐기성 소화 개선 효과 조사)

  • Seonmin Kang;Joonyeob Lee
    • Journal of Environmental Science International
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    • v.33 no.2
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    • pp.131-138
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    • 2024
  • The effect of magnetite particles on the anaerobic digestion (AD) of furfural wastewater was investigated using sequential anaerobic batch tests. The batch tests with four 500 mL anaerobic bioreactors were performed under two conditions: FC treatment for AD of furfural without magnetite particles, and FM treatment for AD of furfural with magnetite particles. The FC bioreactors showed a decreasing methane production rate (MPR) across the sequential batches, with a final batch MPR of 11.3 ± 0.4 mL CH4/L/d, indicating the need for a methanogenesis enhancer to achieve high-rate AD of furfural. Conversely, FM bioreactors exhibited significantly higher MPR, exceeding FC values by 4-196%, with a final batch MPR of 33.5 ± 0.1 mL CH4/L/d, which was about three times higher than FC. Additionally, FM bioreactors had faster degradation rates of furfural, valeric acid, and acetic acid compared to FC, with values exceeding those in PC by 3.0, 1.14, and 2.8 times, respectively. These results demonstrate that magnetite particles can enhance the AD of furfural not only by accelerating methanogenesis but also by accelerating the anaerobic degradation of furfural and its intermediates, such as volatile fatty acids. This study provides valuable insights for developing high-rate AD systems for furfural wastewater treatment.

Clinical study on treatment of HIVD of lumbar spine using Scolopendrid herbal acupuncture (오공약침(蜈蚣藥針)을 이용한 요추간판탈출증(腰椎間板脫出症) 치료(治療)의 임상적(臨床的) 연구(硏究))

  • Koh, Kang-Hoon;Park, So-Young;Choi, Hoi-Gang;So, Ki-Sook;Hwang, Wu-Jun;Lee, Kun-Mok;Kim, Sung-Chul
    • Journal of Acupuncture Research
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    • v.19 no.3
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    • pp.192-206
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    • 2002
  • Objective : This study is performed for the purpose of examining into the efficacy of the scolopendrid(Scolopendra morsitans L) which has been used among the Korean people for the H.I.V.D of lumbar spine. Methods & Results : Using the herbal acupuncture made of scolopendrid(Scolopendra morsitans L), we treated the 20 H.I.V.D patients for 1 week and operated 4 pre and post treatment test ; D.I.T.I, 6 kinds of physical test, Oswestry disability index, and self-conscious pain rate. Trough the test, we saw 43-95% of efficacy rate in each test. And all of the 7 acupuncture point in D.I.T.I, Oswestry disability index and self-conscious pain rate test showed statistically valuable change. Conclusion : We brought to the conclusion that the scolopendrid herbal acupuncture has possibility to be efficient to cure the H.I.V.D patients. So we suggest the possibility to use this new remedy for the H.I.V.D.

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Bio-regeneration of Ion-exchange Resin for Treating Reverse Osmosis Concentrate (RO 농축폐액의 처리를 위한 이온교환수지의 생물재생)

  • Bae, Byung-Uk;Nam, Youn-Woo
    • Journal of Korean Society on Water Environment
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    • v.30 no.5
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    • pp.517-523
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    • 2014
  • In order to remove both nitrate and sulfate present in the concentrate of RO(reverse osmosis) process, a combined bio-regeneration and ion-exchange(IX) system was studied. For this purpose, both denitrifying bacteria(DNB) and sulfate reducing bacteria(SRB) were simultaneously cultivated in a bio-reactor under anaerobic conditions. When the IX column containing a nitrate-selective A520E resin was fully exhausted by nitrate and sulfate, the IX column was bio-regenerated by pumping the supernatant of the bio-reactor, which contains MLSS concentration of $125{\pm}25mg/L$, at the flowrate of 360 BV/hr. Even though the nitrate-selective A520E resin was used, the breakthrough curves of ionic species showed that sulfate was exhausted earlier than nitrate. The reason for this result is due to the fact that the concentration of sulfate in RO concentrate was 36 to 48 times higher than nitrate. The bio-reactor was successfully operated at a volumetric loading rate of 0.6 g $COD/l{\cdot}d$, nitrate-N loading rate of 0.13 g $NO_3{^-}-N/l{\cdot}d$, and sulfate loading rate of 0.08 g $SO_4{^{2-}}/l{\cdot}d$. The removal rate of SCOD, nitrate-N, sulfate was 90, 100, and 85%, respectively. When the virgin resin was fully exhausted and consecutively bio-regenerated for 2 days, 81% of nitrate and 93% of sulfate were reduced. When the virgin resin was repeatedly used up to 4 cycles of service and bio-regeneration, the ion-exchange capacity of bio-regenerated resin decreased to 95, 91, 88, and 81% of virgin resin.

Effect of Nozzle Orifice Shape and Nozzle Length-to-Diameter Ratio on Internal and External Flow Characteristics of Diesel and Biodiesel Fuel (노즐 오리피스 형상 및 형상비가 디젤과 바이오디젤 연료의 노즐 내부 및 외부 유동특성에 미치는 영향)

  • Park, Su-Han;Suh, Hyun-Kyu;Lee, Chang-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.3 s.258
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    • pp.264-272
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    • 2007
  • The aim of this study is to investigate the effects of nozzle orifice shapes and the nozzle length-to-diameter ratio(L/D) on the nozzle cavitation formation inside the orifice and the external flow pattern. The nozzle used in this work was tested the taper orifice nozzle and the rectangular orifice nozzle which was made from the transparent acrylic acid resin. For studying the effect of the nozzle L/D ratio, it was used to three L/D ratios of 3.33, 10, and 20. The cavitation flow of nozzle was visualized by using the ICCD camera and optical system. This work revealed that the flow rate and discharge coefficient($C_d$) of the taper orifice nozzle was larger than those of the rectangular orifice nozzle at the same injection pressure. The cavitation flow was observed in the nozzle orifice at the low injection pressure and the breakup of liquid jet was promoted as the L/D ratio is decreased. The cavitation of biodiesel fuel was formed at the lower injection pressure than that of diesel fuel because of higher viscosity and density.

C-reactive protein and N-terminal pro-brain natriuretic peptide discrepancy: a differentiation of adenoviral pharyngoconjunctival fever from Kawasaki disease

  • Choi, Jung Eun;Kang, Hee Won;Hong, Young Mi;Sohn, Sejung
    • Clinical and Experimental Pediatrics
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    • v.61 no.1
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    • pp.12-16
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    • 2018
  • Purpose: To differentiate adenoviral pharyngoconjunctival fever (PCF) from acute Kawasaki disease (KD) using laboratory tests before results of virus-real time polymerase chain reaction and ophthalmologic examination are obtained. Methods: Baseline patient characteristics and laboratory measurements were compared between 40 patients with adenovirus infection and 123 patients with KD. Results: The patients with adenovirus infection were generally older than those with KD (median: 3.9 years vs. 2 years, P=0.000). White blood cell and, platelet count, and aspartate aminotransferase, alanine aminotransferase, and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels showed significant differences between the 2 groups, but the C-reactive protein (CRP) levels did not ($6.8{\pm}3.0mg/dL$ vs. $8.3{\pm}5.8mg/dL$, P=0.126). In the adenovirus infection group, the CRP levels were <1, <3, <10, and ${\geq}10mg/dL$ in 2 (5%), 3 (7.5%), 30 (75%), and 5 patients (12.5%), respectively. The cutoff NT-proBNP level was 265 pg/mL. Discrepancy was defined as CRP and NT-proBNP levels of ${\geq}3$ or <3 mg/dL, and <265 or ${\geq}265pg/mL$, respectively. Among the 35 patients with adenovirus infection whose CRP levels were ${\geq}3mg/dL$, 29 (82.9%) showed a discrepancy. Conversely, of the 103 patients with KD whose CRP levels were ${\geq}3mg/dL$, 83 (80.6%) showed no discrepancy. Between the groups, a significant difference in discrepancy rate was observed (P=0.000). None of the patients with adenovirus infection had CRP and NT-proBNP levels of <3 mg/dL and ${\geq}265pg/mL$, respectively. Conclusion: With a sensitivity of 82.9% and a specificity of 80.6%, CRP and NT-proBNP levels may differentiate between adenoviral PCF and acute KD.

Implications of Temperature and Humidity on Pupation Patterns in the Silkworm, Bombyx mori L.

  • Lakshminarayana, P.;Naik, S.Sankar;Reddy, N.Sivarami
    • International Journal of Industrial Entomology and Biomaterials
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    • v.5 no.1
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    • pp.67-71
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    • 2002
  • The implications of temperature (25,30 and 35$^{\circ}C$) and relative humidity (60, 70 and 80%) on the pupation patterns were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB4D2 and their hybrid, PM ${\times}4 NB4D2 were reared under experimental conditions under natural day photoperiodic (LD 12: 12) condition. The three developmental marker events viz., larval ripening, pharate pupal formation and pupal formation occurred at or around the beginning of the photo-phase. The computed of mean vector (equation omitted), based on the circular statistics, also confirmed the above. However, the length of mean vector, r and the mean vector angular variance, s varied according to temperature and humidity conditions imposed; the variations being non-significant. Extreme temperature and humidity conditions, however, resulted in reduction in pupation rate (%) for PM and PM ${\times}4 NB4D2. On the other hand, in NB4D2 pupation percentage reduced below the economic level. The temperature and humidity together seems to exert synergic impact on the pupation rate at least in the silkworm Bombyx mori, L.

Continuous electricity generation in microbial fuel cells with non-precious metal catalysts (비귀금속촉매 미생물연료전지의 연속운전을 통한 전기 생산)

  • Moon, Chungman;Kim, Dong-Hoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.23 no.1
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    • pp.45-51
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    • 2015
  • In this study, continuous microbial fuel cells (MFCs) were operated using non-precious metal catalysts such as iron(II) phthalocyanine (FePc) and cobalt tetramethoxyphenylporphyrin (CoTMPP)) as alternative cathode catalysts for platinum. To evaluate MFCs performance, operational conditions of organic loading rate (OLR) (0.5~3 g COD/L/d) and hydraulic retention rate (HRT) (0.25~1 day) were changed. Power density of MFCs were determined by cathode electrode performance. The maximum power density was $3.3W/m^3$ with platinum at OLR 3 g COD/L/d. Given each HRTs at 1 g COD/L/d, FePc showed to be a better alternative for platinum than CoTMPP because the power density of MFC with FePc was similar to that of MFC with platinum. CoTMPP catalyst, however, showed the lowest power density due to increase of internal resistance during continuous operation.