• Title/Summary/Keyword: RO

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Estimation of Demand for and Proper Capacity of Ro-Ro Berths in Korea-Japan Trade (한일간 Ro-Ro 부두 수요 및 적정 규모 추정)

  • Kim, Yul-Seong;Lee, Kyung-Nam;Kang, Dal-Won
    • Journal of Korea Port Economic Association
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    • v.31 no.3
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    • pp.107-120
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    • 2015
  • International logistics systems for cross-border trading aim not only to reduce costs and time, but also to maximize added value. For accuracy of shipping time, cost reduction, rapidity, and safety improvement, demand for Ro-Ro shipping as a global supply chain operating system has increased. To anticipate these demands, this study estimates the optimal demand and scale of Ro-Ro berth construction by analyzing shipping volumes between Korea and Japan. Based on Ro-Ro shipping speeds and distances between Korea and Japan, the shipping volume (container and general cargo) of Busan port is sorted into two separate zones. After analyzing the ratio of items that have great potential benefits from using Ro-Ro shipping, we estimate possible shipping volumes using Ro-Ro berth provision. The results reveal that two berths for 20,000t vessels are additionally required to accommodate the estimated volume. Results suggest the construction of an exclusive Ro-Ro berth in Busan port. This would not only accommodate the demand between Korea and Japan, but also provide a way to avoid the lean-to-one-side port policy.

Hydraulic Model Experiment on the Circulation in Sagami Bay, Japan (II) - Dependence of the Circulation Pattern on External and Internal Rossby Number in Baroclinic Rotating Model

  • Choo Hyo-Sang;Sugimoto Takasige
    • Fisheries and Aquatic Sciences
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    • v.5 no.1
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    • pp.5-20
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    • 2002
  • To investigate the effect of mechanical parameters on the circulation and its fluctuation in Sagami Bay, baroclinic model experiments were carried out by use of a two-layer source-sink flow in a rotating tank. In the experiment, a simple coastal topography with flat bottom was reproduced. The results show that the path of the Through Flow, which corresponds to the branch current of the Kuroshio, depends on external Rossby number (Ro) and internal Rossby number $(Ro^*)$, and divided into two regimes. For $Ro^*\leq1.0$ in which Rossby internal radius of deformation of the Through Flow is smaller than the width of the approaching channel, the current flows along the Oshima Island as a coastal boundary density current separated from the western boundary of the channel. For $Ro^*>1.0$ it changes to a jet flow along the western boundary of the channel, separated from the coast of Oshima Island. The current is independent on both Ro and Ro* in the regime of $Ro^*>1.0,\;Ro\geq0.06$ and $Ro^*\leq1.0,\;Ro\geq0.06$. The pattern of the cyclonic circulation in the inner part of the bay is also determined by Ro and Ro*. In case of $Ro^*\leq1.0$, frontal eddies are formed in the northern boundary of the Through Flow. These frontal eddies intrude into the inner part along the eastern boundary of the bay providing vorticity to form and maintain the inner cyclonic circulation. For $Ro^*>1.0$, the wakes from the Izu peninsula are superposed intensifying the cyclonic circulation. The pattern of the cyclonic circulation is divided into three types; 1) weak cyclonic circulation and the inner anticyclonic circulation $(Ro<0.12)$. 2) cyclonic circulation in the bay $(0.12\leq Ro<0.25)$. 3) cyclonic circulation with strong boundary current $(RO\geq0.25)$.

Test method and Requirements of Water-Based Fire-Fighting Systems for RO-RO Spaces and Special Category Spaces (Ro-Ro Space 화재진압성능 평가를 위한 시험절차 및 성능요건)

  • Kwark, Jihyun;Lee, Doo-Hyun;Kim, Young-Han
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2012.06a
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    • pp.199-200
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    • 2012
  • Test method and requirements of fixed water-based fire-fighting systems for Ro-Ro spaces and special category spaces were introduced for research engineer's reference.

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A Study on the Removal of Dissolved Matter in Groundwater and Characteristics of Fouling using NF and RO (NF와 RO를 이용한 지하수중 용존성 물질의 제거와 막 오염의 특성에 관한 연구)

  • Gwon, Eun-Mi;Yu, Myong-Jin
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.12
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    • pp.2205-2213
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    • 2000
  • To investigate removal efficiency of dissolved matter by NF and RO, a pilot plant was operated for six months using groundwater treated by UF membrane. After the pilot plant operation, we performed autopsy test to identify characteristics of foulant attached on the membrane surface applying the used NF and RO in the pilot plant test. In autopsy test, we measured permeate flux and recovery rate of flux by chemical cleaning in each membrane. We also analyzed chemical cleaning disposal to examine component of foulant. Permeate flux of NF and RO1 showed rapid decline after 100 days of operation. Especially, reduction of specific flux in RO1 was more serious than in NF. Specific flux of RO2 with a low recovery rate resulted in gradual flux decline. Removal efficiencies of dissolved inorganic matters as a conductivity were 76.3%, 88.2% and 95.3% respectively for NF, RO1 and RO2, and RO2 presented the highest removal efficiency. And those of dissolved organic matters as TOC were about 80% for both NF and RO. The specific flux of membranes declined gradually from the feed water inlet to outlet of the membrane module and it showed that membrane fouling increased along the feed flow direction. Namely, concentration of pollutants became higher and volume of feed water was less as the feed flow approached to the outlet. It seemed that major foul ants were Ca consolidated into inorganic material and Si consolidated into organic material on the membrane surface. Fe was a great contribution to irreversible fouling. The SEM results indicated that the organic matter was attached to the first layer, closer to the membrane, and then inorganic matter with tetragonal shape layered over them. We could not observe biofouling because microorganism, which was cause of biofouling, was almost pretreated in UF membrane.

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An experimental study on development of water mist fire-fighting systems for Ro-Ro spaces (Ro-Ro 구역용 미분무 소화설비의 개발을 위한 실험적 연구)

  • Kwark, Ji-Hyun;Kim, Young-Han
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.8
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    • pp.946-952
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    • 2013
  • Large scale fire tests were conducted to develop water mist nozzles as a component of fixed water- based fire fighting systems for Ro-Ro spaces and special category spaces. Fire scenarios for this system consist of two cases which are for cargo fire in a simulated truck and for passenger vehicle fire, and each case has 3 different tests according to the position between fixed water mist nozzles and fire source. Every experiment proceeded for 30 minutes and acceptance criteria were based on gas temperature, fuel package's damage and ignition of targets. This study primarily dealt with the experimental results of cargo fire and focused on fire suppression capability in accordance with discharge pressure, flow rate and flow characteristics like swirl and penetration of the developed water mist nozzles. It appeared that low pressure water mist nozzles with about 40 L/min were able to control fire occurred in Ro-Ro spaces.

A study on reducing scale formation on the RO membrane using carbon dioxide (CO2를 이용한 RO 막의 스케일 생성 저감 연구)

  • Pyo, Minsu;Choi, Younggyun
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.4
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    • pp.391-399
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    • 2016
  • In this study, carbon dioxide ($CO_2$) was used as an inhibitor of scale production on the surface of RO membrane. In order to compare the effects of $CO_2$ injection on scale production, four RO modules: 1) without $CO_2$ injection and anti-scalant (RO module #1), 2) with only $CO_2$ injection (RO module #2), 3) with only anti-scalant (RO module #3), 4) with both $CO_2$ injection and anti-scalant (RO module #4), were operated for 60 days under constant flux mode. The trans-membrane pressure (TMP) was observed to decrease significantly in RO modules with $CO_2$ injection as compared with the other RO modules. When the feed water pH was controlled at 5.0 by injecting $CO_2$, the maximum TMP in RO modules #2 and #4 was founded to decrease by 42 and 40%, respectively. Moreover, the $Ca^{2+}$ concentration in the concentrate was 20mg/L lower in RO modules without $CO_2$ injection which is attributed to the scale formation on the surface of the RO membranes. The SEM-EDS analysis further showed a serious fouled RO membrane surface in RO modules #1 and #3.

Development of Optimization Mixture Tea prepared with Roasting Mulberry Leaf and Fruit (반응표면분석을 이용한 로스팅 뽕잎과 오디 혼합차 개발)

  • Kim, Ae-Jung;Kang, Hyun-Jeong;Kim, Min-Ju
    • The Korean Journal of Food And Nutrition
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    • v.29 no.6
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    • pp.1040-1049
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    • 2016
  • In this study, we aimed to develop a mixed tea prepared with roasted mulberry leaf and fruit using response surface methodology (RSM). Roasting of mulberry leaf was by 6 stages, as shown in Fig. 1; and mulberry fruit was roasted in 4 stages, as shown in Fig. 2. Subsequently, physicochemical measurements such as total polyphenol content, nitric oxide production content, and ${\alpha}$-glucosidase inhibitory effect were obtained for each sample. Central composite design was applied to prepare samples containing varying contents of roasted mulberry leaf (RoML) and roasted mulberry fruit (RoMF); subsequently, sensory evaluation was conducted. The total polyphenol content of roasted samples (RoML and RoMF) were significantly higher than that of raw samples (RaML and RaMF), respectively. The nitric oxide (NO) production of roasted samples were significantly lower than that of control (LPS induced RAW 264.7 cell). The ${\alpha}$-glucosidase inhibitory effect of roasted samples was significantly higher than that of raw samples, respectively. Based on the RSM estimation for determination of optimum ratio by sensory evaluation (taste, color, and flavor) among 13 mixed samples, the optimum mixing ratio of RoML and RoMF for taste, color, and flavor were 1.64 g (RoML) and 0.88 g (RoMF), 1.35 g (RoML) and 0.92 g (RoMF), 1.65 g (RoML) 1.03 g (RoMF), respectively. Based on results of three sensory evaluations, mixing ratio comprising 1.54 g of RoML and 0.92 g of RoMF is desirable for delicious tea with functionality.

TOXIC MECHANISM OF Ro09-0198 ISOLATED FROM STREPTOVERTICILLIUM (Ro 09-0198의 독성발현 기전에 관한 연구)

  • Choung, Se-Young
    • Toxicological Research
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    • v.6 no.1
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    • pp.109-119
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    • 1990
  • Ro09-0198, a cyclic peptide isolated from culture filtrates of Streptoverticillium griseoverticillatum, induced lysis of erythrocytes. Ro-09-0198-induced hemolysis was temperature-dependent and the sensitivity of hemolysis differed greatly among animal species. Preincubation of the peptide with phosphatidylethanolamine reduced the hemolytic activity, whereas other phospholipids present in erythrocytes in nature had no effect. A study of the structural requirements on phosphatidylethanolamine necessary for interaction with the peptide indicates that Ro09-0198 recognizes strictly a particular chemical structure of phosphatidylethanolamine: dialkylphosphoethanolamine as well as 1-acylglycerophosphoethanolamine showed the same inhibitory effct on hemolysis induced by Ro09-0198 as diacylphosphatidyl-ethanolamine, whereas phosphoethanolamine gave no inhibitory effect. Neither phosphatidyl-N-monomethylethanolamine nor alkylphosphopropanolamine had an inhibitory effect. Proton resonances of the peptide were observed in dimethyl sulfoxide solution in the presence of 1-dodecanoyl-sn-glycerophosphoethanolamine. This peptide caused permeability increase and aggregation of liposomes containing phosphatidylethanolamine. A glycerol backbone and a primary amino group of phosphatidylethanolamine are necessary for interaction with Ro09-0198 to cause membrane damage. Ro09-0198 induced a selective permeability change on liposomes. Glucose and umbelliferyl phosphate were effluxed significantly, but sucrose was only slightly permeable and inulin could not be released. Platelet aggregation and serotonin release simultaneously induced by Ro09-0198. Addition of peptide to rat platelet, loaded with the fluorescent $Ca^{++}$ chelator quin-2, caused immediate rise in cytosolic free $Ca^{++}$ to liposomal membrane containing phosphatidylethanolamine was observed dose dependently.

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Landfill Leachate Treatment and Boron Removal by Reverse Osmosis (RO막을 이용한 매립지 침출수 처리 및 붕소 제거)

  • Jung, Soojung;Na, Sukhyun;Bae, Sangok;Lim, Byungjin
    • Journal of Korean Society on Water Environment
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    • v.28 no.5
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    • pp.657-662
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    • 2012
  • This study was carried out to evaluate the removal rate of organic and inorganic matters from landfill leachate using pre-treatment process as coagulation and limonite adsorption, and membrane process as RO (reverse osmosis) and NF(nanofiltration). By adding limonite adsorption as pre-treatment process, about 40% of organic matters in leachate was removed through pre-treatment process and 74.7% of boron was removed after RO process without pH adjustment. The rejection rate of boron in RO process mainly depends on the pH and increased at pH value of 10. RO process was performed as two stage system adjusting pH condtion to 7 and 10 in second RO stage for boron removal. Most (>90%) of TOC, Cl- and inorganic matters as Ca was rejected in first RO stage, the residue was rejected in second RO and the rejection rate was above 97%. Considering economic efficiency of operation cost, NF substituted for the first RO and total removal rate of TOC was above 90%. Through RO system toxicity to Daphnia in leachate was removed completely.