• Title/Summary/Keyword: Attached growth

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Biological Removal Characteristics by the Internal Recycle Rate in the Attached Growth Process (부착증식공정에서 내부 반송율 변화에 따른 생물학적 제거 특성)

  • 박충기;김병욱;임재명
    • Journal of environmental and Sanitary engineering
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    • v.14 no.4
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    • pp.110-116
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    • 1999
  • This study was conducted to investigate the contaminants removal efficiency and the optimal operating parameters by the internal recycle rate (IRR) in the combining A2/O process with fixed film. The average removal efficiency of BOD and COD was 92.5%~94.6%, 73.9%~87.0% in RUN 1 and 91.9%~94.7%, 77.7%~89.0% in RUN 2, respectively. Organic removal efficiency, at two different hydraulic retention time of 10 and 14hr, was similar. At 50% of the internal recycle rate, organic removal efficiency was somewhat higher than the other. Total nitrogen (T-N) and total phosphorus (T-P) were removed, highly, at 50% of internal recycle rate. It could be suggested by this study that the optimum internal recycle rate is 50% and hydraulic retention time is 14hr.

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Research on synchronization between smart toys and smart phones for classifying smart toys

  • Jung, Sugkyu
    • International Journal of Internet, Broadcasting and Communication
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    • v.9 no.4
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    • pp.25-30
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    • 2017
  • Market of smart toys is showing rapid growth globally. Recently, new types of toys which can be synced with smart phones, so called smart toys, are being released continuously. As a result, products from RC cars with camera attached that can be driven and monitored using a connected smart phone to toys that would call kid's name once it has been entered through a mobile app. It has been confirmed that there are various way to connect those toys with mobile devices. In this paper, functions of smart toys are classified, and research on different synchronization methods of the toys sold in market as of July, 2017 are explained.

Organic Characteristic of Piggery Wastewater and Kinetic Estimation in Biofilm Reactor (생물막 반응조에서 돈사폐수의 유기물 특성 및 동력학계수 산정)

  • Rim, Jay-Myoung;Han, Dong-Joon;Kwon, Jae-Hyuk
    • Journal of Industrial Technology
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    • v.16
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    • pp.51-60
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    • 1996
  • This research was performed for the fundamental data using a advanced treatment process of piggery wastewater. Characteristics of influent wastewater was divided with various methods in fixed biofilm batch reasctor. Fractons of organic were divided into readily biodegradable soluble COD(Ss), slowly biodegradable COD(Xs), nonbiodegradable soluble COD($S_I$), and nonbiodegradable suspended COD($X_I$). Experimental results were summerized as following : i) biodegradable organics fraction in piggery wastewater was about 88.1 percent, and fraction of readily biodegradable soluble COD was about 66.1 percent. ii) Fractions of nonbiodegradable soluble COD was 11~12 percent, and soluble inert COD by metabolism was producted about 6~8 percent. iii) Active biomass fraction of attached biofilm was about 54.7 percent, and substrate utilization rate and maximum specific growth rate of heterotrophs were $8.315d^{-1}$ and $3.823d^{-1}$, respectively.

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Development of Biaxial Tension & Shear Tester using Stepper Motor with Harmonic Driver (감속 스텝모터를 이용한 2축 인장·전단 시험기의 개발)

  • Choi, Byung-Sun;Bae, Won-Ho;Chai, Young-Suck
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.4
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    • pp.379-386
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    • 2001
  • The lower toughness or brittle materials for mechanical test lead to the additional requirement that applied displacements be controlled with high resolution. Biaxial tension and shear tester using stepper motor with harmonic driver is shown. The device had to be high resolution so that the crack initiation process of slow extension and steady growth could be examined, Grip plates were connected to a linear bearing and actuator. The actuators consisted of stepper motors with harmonic driver connected to pre-loaded ball screw and nut assemblies. The encoders and motor controllers were connected to a personal computer so that arbitrary displacements histories could he prescribed in normal and tangential directions. The linear bearings were used to react loads perpendicular to their axes while allowing low friction, parallel movement of the attached grips. Load cells measured the reactions normal and tangential. the loads measured the reactions were recorded by the computer.

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Coupled Vibration of Lateral and Torsional Vibrations in a Rotating Shaft Driven through a Universal Joint - Derivation of Equations of Motion and Stability Analysis - (유니버셜 조인트에 의해 구동되는 회전축의 횡진동과 비틀림진동의 연성진동 - 운동방정식의 유도 및 안정성해석 -)

  • 김정렬;전승환;이돈출
    • Journal of KSNVE
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    • v.9 no.3
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    • pp.461-465
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    • 1999
  • This paper presents theoretical analyses for unstable vibrations caused by the couple of bending and torsion in a rotating shaft driven through a universal joint. A driving shaft is assumed to be rigid and to rotate with a constant angular velocity. The driven shaft system consists of a flexible shaft with a circular section and a symmetrical rotor attached at a point between the shaft ends. Equations of motion derived hold with an accuracy of the second order of shaft deformations, and are analyzed by the asymptotic method. The vibrations become unstable when the driving shaft rotates with the angular velocity to be approximately equal to half of the sum of the natural frequencies for whirling and torsional vibrations.

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A Study on Cultivation of Petalonia fascia (Scytosiphonales, Phaeophyta) by Vegetative Regeneration

  • Lee,Kang-Hwa;Cho,Jae-Hyun;Shin,Jong-Ahm
    • ALGAE
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    • v.18 no.4
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    • pp.333-339
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    • 2003
  • To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

Solid medium integrated impedimetric biosensor for detection of microorganisms (미생물 검침을 위한 고체 배지 임피던스 센서)

  • Choi, Ah-Mi;Park, Jae-Sung;Jung, Hyo-Il
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1629-1632
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    • 2008
  • Rapid, real-time detection of pathogenic microorganisms is an emerging and quickly evolving field of research, especially with regard to microorganisms that pose a major threat to public health. Herein, a new method that uses bioimpedance and solid culture medium for the real-time detection of microorganisms is introduced. We fabricated a new impedimetric biosensor by integrating solid media and two plane electrodes attached on two facing sides of an acryl well. During bioelectrical impedance analysis, the solid medium showed the characteristics of a homogenous conductive material. In a real-time impedance measurement, our solid-medium biosensor could monitor bacterial growth in situ with a detection time of ${\sim}4$ hrs. Our data indicate that the solid-medium biosensor is useful for detecting airborne microorganisms, thereby providing a new analytical tool for impedance microbiology.

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Basis or In-Vivo and In-Vitro Thrombosis Detection of Mechanical Valve (In-Vivo 및 In-Vitro 실험을 통한 기계식 판막의 혈전현상 검출을 위한 기초연구)

  • Lee, H.S.;Lee, S.H.;Kim, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.113-117
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    • 1997
  • In this paper we detected the thrombosis formation by spectral analysis and neural network. Using microphone and amplifier, we measured the sound from the mechanical valve which is attached to the pneumatic ventricular assist device. The sound was sampled by A/D converter and the periodogram is the main algorithm or obtaining spectrum. We made the valvular thrombosis models using pellethane and silicon and they are thrombosis model on the disk, around the sewing ring and fibrous tissue growth across the orifice of valve. The spectrum of normal and 5 kinds of thrombotic valve were obtained and primary and secondary peak appeared in each spectrum waveform. So to distinguish the secondary peak of normal and thrombotic valve quantatively, 3 layer back propagation neural network.

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Nitrogen Removal in the Multi-stage Bed Attached Growth Process of $A^2/O$ System with Interanal Recycle Ratio (다단층 부착성장 공법($A^2/O$향)에서 순환비에 따른 질소제거)

  • 최규철;윤용수;정일현
    • Journal of environmental and Sanitary engineering
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    • v.12 no.3
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    • pp.95-102
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    • 1997
  • The process which can stabilize water quality of treatment and improve nitrogen removal rate under the condition of high organic loading was developed by charging fibrous HBC media to single sludge nitrification-denitrification process. This process was operated easier, minimized the treatment cost, and shortened the retention time. To improve T-N removal rate, a part of nitrifing liquid at aerobic zone was recycled to anoxic zone by approximate internal recycle ratio. The experimental results are as follows ; T-N removal efficiency in the organic volumetric loading 0.14-0.19 kg/COD/m$^{3}$·d was obtained asmaxium of 85% at internal recycle ratio 2.5 and in more ratio than this it was decreased. Organic removal efficiency was about 91% under the overall experimental conditions and not influenced by recycle ratio.

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Characteristics of continuous operation of the anaerobic biofilm reactor (혐기성 생물막 반응기의 초기 운전특성)

  • 이승란;김도한;나영수;이창한;박영식;윤태경;송승구
    • Journal of Environmental Science International
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    • v.11 no.3
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    • pp.209-214
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    • 2002
  • The lab-scale anaerobic continuous reactor which was filled with the sludge of anaerobic digestion from Suyoung wastewater treatment plant was operated by feeding of various concentrations and flow rates. This experiment indicated that more than 6,870 mgCOD/L of substrate concentration was required to promote good metabolism and growth of anaerobic biomass. And increasing loading rate slowly was also required in order to treat substrate of higher concentration and higher loading rate. The substrate concentration of about 10,000 mgCOD/L was adequate to generate biogas efficiently. The pH was sharply decreased at the onset of higher leading rate, but the pH was restabilized soon at 8. During the experiment, the amount of the attached biomass was kept constant.