• Title/Summary/Keyword: suspending

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Influence of Iron Phases on Microbial U(VI) Reduction

  • Lee, Seung-Yeop;Baik, Min-Hoon;Lee, Min-Hee;Lee, Young-Boo;Lee, Yong-Jae
    • Journal of Soil and Groundwater Environment
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    • v.16 no.6
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    • pp.58-65
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    • 2011
  • The bacterial uranium(VI) reduction and its resultant low solubility make this process an attractive option for removing U from groundwater. An impact of aqueous suspending iron phase, which is redox sensitive and ubiquitous in subsurface groundwater, on the U(VI) bioreduction by Shewanella putrefaciens CN32 was investigated. In our batch experiment, the U(VI) concentration ($5{\times}10^5M$) gradually decreased to a non-detectable level during the microbial respiration. However, when Fe(III) phase was suspended in solution, bioreduction of U(VI) was significantly suppressed due to a preferred reduction of Fe(III) instead of U(VI). This shows that the suspending amorphous Fe(III) phase can be a strong inhibitor to the U(VI) bioreduction. On the contrary, when iron was present as a soluble Fe(II) in the solution, the U(VI) removal was largely enhanced. The microbially-catalyzed U(VI) reduction resulted in an accumulation of solid-type U particles in and around the cells. Electron elemental investigations for the precipitates show that some background cations such as Ca and P were favorably coprecipitated with U. This implies that aqueous U tends to be stabilized by complexing with Ca or P ions, which easily diffuse and coprecipitate with U in and around the microbial cell.

Studies on the Detergency Characteristics of Free Fatty Acid in Oily Soil. Part 1. Detergency of Palmitic Acid. (오염중의 유이지방산이 세척에 미치는 영향(제일보 팔미트산의 세척 특성))

  • Chung Hae Won;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.1 no.1
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    • pp.31-37
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    • 1977
  • The effects of surfactants and concentration of NaOH in surfactant solution on the removal of free fatty acid soil from cotton fabrics were investigated. Cotton fabrics were soiled with palm itic acid which is the most common fatty acid found in natural oily soil and washed in Lauder-ometer with various types of surfactant with or without NaOH. The rate of soil removal was estimated by analyzing palmitic acid contents in fabric before ar d after washing. Analysis of palmitic contents was made by extracting palmitic acid with azeotropic mixture of alcohol-benzene and the extracts were titrated with standard NaOH solution. It was shown that the types of surfactant are important factor in free fatty acid removal and the efficiency increases in the following order: SLS$90\%$ of initial sorption. In relation to the mechanism of detergency, the suspending and emulsifying power of surfactants were also examined. From the results of this experiments, it could be concluded that the soap formation with alkali and the suspending power of surfactant arc significant factors in free fatty acid soil removal, but the emulsifying power of it is neglizible.

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Synthesis Conditions of Magaldrate and Rheological Characteristics of its Aqueous Suspensions (마갈드레이트의 합성조건과 그 현탁액의 유동학적 특성)

  • Shin, Wha-Woo;Choi, Kwang-Sik
    • YAKHAK HOEJI
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    • v.40 no.1
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    • pp.25-35
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    • 1996
  • Magaldrate. an antiacid was synthesized by reacting magnesium oxide, aluminum sulfate, and dried aluminum hydroxide gel. The optimum synthesis conditions based on the yield of t he product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magaldrate were as follows: Reaction temperature; 61~$85{\circ}C$, concentration of two reactants. Mgo and $Al(OH)_3$: 16~19.8%, molar concentration ratio of two reactants, [MgO]/[$Al(OH)_3$]; 4.2~5.0, temperature of washing water; 36~$41^{\circ}C$ and drying temperature of the product: 76~$80^{\circ}C$. Magaldrate was synthesized under the optimum synthesis conditions and identified by analyzing the chemical composition, and by differential scanning calorimetry and X-ray diffraction method. The Magaldrate sample synthesis under these conditions was used to prepare 15.6% Magaldrate original suspension which was utilized to make 13% Magaldrate suspension dispered in various concentrations of eight types of suspending agents. The acid-neutralizing capacity of 13% Magaldrate suspension dispersed in 0.25% suspending agents was examined by Rosset-Rice method. The maximum pH was reached within 1 minute in all suspension tested, and duration maintained between pH 3~5 was decreased in the order of Na alginate Na silicate(meta) Veegum HV pectin agar>Na>CMC>xanthan gum>bentonite. It was found that the hysteresis loop area was increased with temperature in the case of Riopan Plus and the addition of agar, whereas the area was decreased with temperature in the case of the addition of Na alginate and xanthan gum. 13% Magaldrate suspension tends to sediment by the addition of bentonite.

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A Study on the Remedial Cases of Anticipatory Breach in int'l Sales (국제물품매매에서 이행기전 계약위반에 대한 구제권 연구(사례를 중심으로))

  • Ha, Kang-Hun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.39
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    • pp.3-26
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    • 2008
  • CISG provides the Convention's default provisions on anticipatory breach. Article 71 permits the aggrieved party to suspend the performance of his obligations if it becomes apparent that the other party will not perform a substantial part of his obligations after the conclusion of the contract. The aggrieved party must give notice of the suspension to the other party and if he provides adequate assurance of his performance, the party must continue with performance. Article 72 authorizes the aggrieved party to avoid the contract to the date of performance when it is clear that the other party will commit a fundamental breach. The aggrieved party is also required to give the other party notice of his intent to avoid the contract if time allows. The requirements for avoidance under Article 72 are more stringent than those for suspension under Article 71. Article 72 requires reasonable prior notice only if time allows, while article 71 requires immediate notice with no exceptions.

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In Situ Ruminal Digestion Kinetics of Forages and Feed Byproducts in Cattle and Buffalo

  • Sarwar, M.;Mahr-un-Nisa, Mahr-un-Nisa;Bhatti, S.A.;Ali, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.2
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    • pp.128-132
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    • 1998
  • The relative disappearance and rate of degradation of dry matter (DM) and neutral detergent fiber (NDF) of nine different feedstuffs were determined by simultaneously suspending groups of substrates, using the nylon bags, in the rumen of males of Sahiwal cattle and Nili-Ravi buffalo. The digestion kinetics of leguminous forages (Lucerne, berseem and cowpeas) and feed byproducts (cotton seed cake, wheat bran and wheat straw) did not differ between the two species. However, the DM and NDF digestibilities and rates of digestion of grasses and wheat straw were greater in buffalo than in cow bulls, indicating that buffaloes are better converters of poor quality roughages than are Sahiwal. The lag time for DM of grasses did not differ between these two species but the NDF lag time was lower in buffalo than in cows, indicating that both the rate and lag time of digestion may be reliable indicators for assessing the NDF quality.

Development of Dynamic Analysis Program Considering Vehicle-Bridge interaction (차량-교량 상호작용을 고려한 동적해석 프로그램 개발)

  • Cho Eun-Sang;Koo Hyoung-Woo;Hwang Won-Sup
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.505-509
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    • 2005
  • Analysis program to estimate the dynamic characteristics of bridge is investigated by using three-dimensional analytical model considering vehicle-bridge interaction. A dynamic interaction models of the vehicle-bridge system are established, which is composed of a vehicle element model and a finite element bridge model. The vehicle models are established according to the structure and suspending properties of vehicle. The dynamic responses of the bridge are calculated. But the computer simulation program is being verified with field tests results, it must be corrected according to them.

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Levitation Control of BLSRM using Adaptive Fuzzy PID Controller (퍼지제어기 기반의 새로운 BLSRM의 축방향지지력 제어)

  • He, Yingjie;Zhang, Fengge;Lee, Donghee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.519-520
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    • 2016
  • BLSRM is a nonlinear, strong coupling and multi-variable system. The conventional control method is vulnerable to uncertain factors such as the load disturbance and satellite parameters change. It is difficult to obtain satisfactory control effect. Basing on a 8/10 BLSRM, whose suspending force control is separated with the torque control, this paper presents adaptive fuzzy PID controller for levitation control, which apply the fuzzy logic control to the conventional PID controller for parameters self-tuning. Both fuzzy and parameters of PID controller are self-tuning on-line, which improve the performance of controller. Finally, simulation and experimental results show the performance of the proposed method.

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Effect of glucose and nitrogen sources on production of gellan

  • Im, Seong-Mi;Lee, Ji-Hyeon;Kim, Seong-Gu
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.418-421
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    • 2001
  • The gellan was produced by Pseudomonas elodea ATCC 31461 under aerobic condition. Gellan provides various functionalities such as gelling, suspending, stabilizing, emulsifying and binding properties in aqueous systems. In this study, the effect of glucose concentration and nitrogen sources concentration, bacto peptone and $NH_4NO_3$, on the cell growth and the production of gellan were evaluated. The maximum specific yield (g gellan/g cell) of 2.22 was obtained at 1.0% of glucose. Bacto peptone increased cell growth. And nitrogen limitation was essential for higher production of gellan. The highest cell and gellan production were abtained at 0.5 g/${\ell}$ of bacto peptone without $NH_4NO_3$.

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Self-Sensing Electrostatic Suspension System (자가 검출 방식을 이용한 정전 부상 시스템)

  • 정학근;최창환;박기환
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.454-461
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    • 2000
  • Electrostatic suspension offers an advantage of directly suspending various materials such as conductive materials, semiconductors and dielectric materials without any mechanical contacts. This is a specific feature compared with electromagnetic suspension which can suspend only ferro-magnetic material. In general, the electrostatic suspension systems require position sensors for stabilizing the suspended object. Therefore, a lot of displacement sensors and a switching circuit are required for moving the object through a long distance. In order to circumvent this problem, this paper proposes a self-sensing method which can provide the gap displacement between electrodes and suspended object without external sensors. Moreover a simple on-off controller is presented for stabilization. Experimental validation of the proposed scheme has been performed through the successful levitation of a 4-inch silicon wafer.

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Design of 1-DOF Walking Orthosis for Paralysis Patients (하지 마비 환자를 위한 1 자유도 보행 보조기 설계)

  • 정철희;최용제
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1137-1142
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    • 2004
  • Walking training is one of the most important rehabilitation processes with paralysis patient. Walking training by using an orthosis can help advancing a patient's independent level. However, existing orthoses have some serious demerit of mechanical problem that the knee joint is locked in the state where it is completely extended, which increases energy consumption and fatigue. For this reason, it is suggested, for more practical orthosis, that the knee joint should be placed and it should have capability of suspending patient's weight. In this paper, 1-DOF walking orthosis which compensates the demerit of the existing orthosis and secures patient's mobility has been proposed. New orthosis has been designed under the following two premises. First, the knee joint of the orthosis was designed fold in order for the orthosis to move in a walking pattern similar to that of a normal person. Second, the knee joint was designed to extend during the swing phase and lock safely during the stance phase.

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