• 제목/요약/키워드: treatment systems

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Evaluation of Environmental Impact with Application of the Life Cycle Assessment Method to Swine Waste Treatment Systems (가축분뇨 처리 시스템에 대한 전과정평가 방법을 적용한 환경영향 평가)

  • Shin, Joungdu;Lee, Sun-Ill;Park, Wu-Kyun;Hong, Seung-Gil;Choi, Yong-Su
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.3
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    • pp.64-73
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    • 2013
  • The application of the Life Cycle Assessment (LCA) methodology to analyze the environmental impact to different swine waste treatment systems was investigated. The first part of LCA is to organize an inventory of parameters and emissions released due to the system under investigation. In the following step of the Life Cycle Impact Assessment, the inventory data were analyzed and aggregated in order to finally get one index representing the total environmental burden. For the Life Cycle Impact Assessment (LCIA) the Eco-indicator 95 method has been chosen because this is well documented and regularly applied impact method. Two different swine waste treatment systems such as aerobic and anaerobic digestion systems were chosen as an example for the life cycle impact analysis. For establishing the parameters to be assessed the agricultural environmental effects to above swine waste treatment systems, it has been observed that there was high at T-P emission in anaerobic digestion system and $CO_2$ emission in aerobic digestion system. For Eco-indicator values per environmental effect for swine waste treatment systems related to one tonne of swine waste, it was shown that there was a negative index for global warm potential and soil acidification in aerobic digestion system, but relatively high positive index for eutrophication in anaerobic digestion system.

Effects of different finishing/polishing protocols and systems for monolithic zirconia on surface topography, phase transformation, and biofilm formation

  • Mai, Hang-Nga;Hong, Su-Hyung;Kim, Sung-Hun;Lee, Du-Hyeong
    • The Journal of Advanced Prosthodontics
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    • v.11 no.2
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    • pp.81-87
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    • 2019
  • PURPOSE. The purpose of this study was to evaluate the effects of various protocols and systems for finishing and polishing monolithic zirconia on surface topography, phase transformation, and bacterial adhesion. MATERIALS AND METHODS. Three hundred monolithic zirconia specimens were fabricated and then treated with three finishing and polishing systems (Jota [JO], Meisinger [ME], and Edenta [ED]) using four surface treatment protocols: coarse finishing alone (C); coarse finishing and medium polishing (CM); coarse finishing and fine polishing (CF); and coarse finishing, medium polishing, and fine polishing (CMF). Surface roughness, crystal phase transformation, and bacterial adhesion were evaluated using atomic force microscopy, X-ray diffraction, and streptococcal biofilm formation assay, respectively. One-way and two-way analysis of variance with Tukey post hoc tests were used to analyze the results (${\alpha}=.05$). RESULTS. In this study, the surface treatment protocols and systems had significant effects on the resulting roughness. The CMF protocol produced the lowest roughness values, followed by CM and CF. Use of the JO system produced the lowest roughness values and the smallest biofilm mass, while the ME system produced the smallest partial transformation ratio. The ED group exhibited the highest roughness values, biofilm mass, and partial transformation ratio. CONCLUSION. Stepwise surface treatment of monolithic zirconia, combined with careful polishing system selection, is essential to obtaining optimal microstructural and biological surface results.

New Backstepping-DSOGI hybrid control applied to a Smart-Grid Photovoltaic System

  • Nebili, Salim;Benabdallah, Ibrahim;Adnene, Cherif
    • International Journal of Computer Science & Network Security
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    • v.22 no.4
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    • pp.1-12
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    • 2022
  • In order to overcome the power fluctuation issues in photovoltaic (PV) smart grid-connected systems and the inverter nonlinearity model problem, an adaptive backstepping command-filter and a double second order generalized Integrators (DSOGI) controller are designed in order to tune the AC current and the DC-link voltage from the DC side. Firstly, we propose to present the filter mathematical model throughout the PV system, at that juncture the backstepping control law is applied in order to control it, Moreover the command filter is bounded to the controller aiming to exclude the backstepping controller differential increase. Additionally, The adaptive law uses Lyapunov stability criterion. Its task is to estimate the uncertain parameters in the smart grid-connected inverter. A DSOGI is added to stabilize the grid currents and eliminate undesirable harmonics meanwhile feeding maximum power generated from PV to the point of common coupling (PCC). Then, guaranteeing a dynamic effective response even under very unbalanced loads and/or intermittent climate changes. Finally, the simulation results will be established using MATLAB/SIMULINK proving that the presented approach can control surely the smart grid-connected system.

Effects of binder type and heat treatment temperature on physical properties of a carbon composite bipolar plate for PEMFCs

  • Kang, Dong-Su;Roh, Jea-Seung
    • Carbon letters
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    • v.14 no.2
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    • pp.110-116
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    • 2013
  • This study investigated a developed process for producing a composite bipolar plate having excellent conductivity by using coal tar pitch and phenol resin as binders. We used a pressing method to prepare a compact of graphite powder mixed with binders. Resistivity of the impregnated compact was observed as heat treatment temperature was increased. It was observed that pore sizes of the GCTP samples increased as the heat treatment temperature increased. There was not a great difference between the flexural strengths of GCTP-IM and CPR-IM as the heat treatment temperature was increased. The resistivity of GPR700-IM, heat treated at $700^{\circ}C$ using phenolic resin as a binder, was $4829{\mu}{\Omega}{\cdot}cm$ which was best value in this study. In addition, it is expected that with the appropriate selection of carbon powder and further optimization of process we can produce a composite bipolar plate which has excellent properties.

A Survey of Robotic Technologies for Diagnosis and Treatment of Prostate Cancer (전립선 암 진단 및 치료를 위한 로봇기술 응용 현황)

  • Ahn, Bum-Mo;Park, Ki-Han;Lee, Hyo-Sang;Kim, Jung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.9
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    • pp.852-859
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    • 2010
  • Robotic techniques can be one of the promised solutions to address the prostate cancer which is one of the most important public health problems in medical fields. Despite several past and on-going dedicated researches, the systematic techniques and completed theories have not been established well. Therefore we review the state-of-the-art literature on the applications of engineering technologies with particular focus on diagnosis and treatment of prostate cancer. The current status of the elastography and systematic DRE are presented as novel diagnostic tools, and an overview of the applied technologies to address the limits of the treatment (radical prostectomy and brachytherapy) is reviewed.

Characteristics of Surface Heat Treatment for Carbon Steel as Laser Beam Mode (빔 모드에 따른 탄소강의 레이저 표면 열처리 특성)

  • Kim, Jong-Do;Gang, Un-Ju;Lee, Chang-Jae;Lee, Je-Hun;Seo, Jeong;Lee, Mun-Yong
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.207-209
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    • 2006
  • This study is about an effect on a characteristics of the laser heat treatment as a optic systems which have a transverse beam mode each other. An experiment are carried out using a circular gaussian beam optics and rectangular beam optics. Generally, the optic system which has a uniform power intensity is mainly used in the laser heat treatment process. In this study, we would like to carried out experiments simultaneously using two optic systems and research the differences from a characteristics of the laser heat treatment.

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A Study on the Determination of Dosing Rate for the Water Treatment using Genetic-Fuzzy (유전-퍼지를 이용한 정수장 응집제 주입률 결정에 관한 연구)

  • 김용열;강이석
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.7
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    • pp.876-882
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    • 1999
  • It is difficult to determine the feeding rate of coagulant in the water treatment process, due to nonlinearity, multivariables and slow response characteristics, etc. To deal with this difficulty, the genetic-fuzzy system was used in determining the feeding rate of the coagulant. The genetic algorithms are excellently robust in complex optimization problems. Since it uses randomized operators and searches for the best chromosome without auxiliary informations from a population consists of codings of parameter set. To apply this algorithms, we made the lookup table and membership function from the actual operation data of the water treatment process. We determined optimum dosages of coagulant(LAS) by the fuzzy operation, and compared it with the feeding rate of the actual operation data.

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A Study on Coagulant Feeding Control of the Water Treatment Plant Using Intelligent Algorithms (지능알고리즘에 의한 정수장 약품주입제어에 관한 연구)

  • 김용열;강이석
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.1
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    • pp.57-62
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    • 2003
  • It is difficult to determine the feeding rate of coagulant in the water treatment plant, due to nonlinearity, multivariables and slow response characteristics etc. To deal with this difficulty, the genetic-fuzzy system genetic-equation system and the neural network system were used in determining the feeding rate of the coagulant. Fuzzy system and neural network system are excellently robust in multivariables and nonlinear problems. but fuzzy system is difficult to construct the fuzzy parameter such as the rule table and the membership function. Therefore we made the genetic-fuzzy system by the fusion of genetic algorithms and fuzzy system, and also made the feeding rate equation by genetic algorithms. To train fuzzy system, equation parameter and neural network system, the actual operation data of the water treatment plant was used. We determined optimized feeding rates of coagulant by the fuzzy system, the equation and the neural network and also compared them with the feeding rates of the actual operation data.

A review on recent advances in water and wastewater treatment facilities management for earthquake disaster response (지진발생 대응을 위한 상하수도시설 관리 및 기술 현황에 대한 고찰)

  • Park, Jungsu;Choi, June-Seok;Kim, Keugtae;Yoon, Younghan;Park, Jae-Hyeoung
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.1
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    • pp.9-21
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    • 2020
  • The proper operation and safety management of water and wastewater treatment systems are essential for providing stable water service to the public. However, various natural disasters including floods, large storms, volcano eruptions and earthquakes threaten public water services by causing serious damage to water and wastewater treatment plants and pipeline systems. Korea is known as a country that is relatively safe from earthquakes, but the recent increase in the frequency of earthquakes has increased the need for a proper earthquake management system. Interest in research and the establishment of legal regulations has increased, especially since the large earthquake in Gyeongju in 2016. Currently, earthquakes in Korea are managed by legal regulations and guidelines integrated with other disasters such as floods and large storms. The legal system has long been controlled and relatively well managed, but technical research has made limited progress since it was considered in the past that Korea is safe from earthquake damage. Various technologies, including seismic design and earthquake forecasting, are required to minimize possible damages from earthquakes, so proper research is essential. This paper reviews the current state of technology development and legal management systems to prevent damages and restore water and wastewater treatment systems after earthquakes in Korea and other countries. High technologies such as unmanned aerial vehicles, wireless networks and real-time monitoring systems are already being applied to water and wastewater treatment processes, and to further establish the optimal system for earthquake response in water and wastewater treatment facilities, continuous research in connection with the Fourth Industrial Revolution, including information and communications technologies, is essential.

Present State of Membrane Filtration for Water Treatment in Japan

  • Kiso, Yoshiaki
    • Membrane Journal
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    • v.13 no.1
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    • pp.1-8
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    • 2003
  • Membrane filtration systems have been focusing and increasing rapidly in the filed of drinking water treatment because of several reasons. We describe briefly the present state of membrane filtration processes for drinking water treatment in Japan: including background, objectives, membrane suppliers, and some cases of actual plants.