• Title/Summary/Keyword: Contamination process

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A Study on the Application of Chemical Grouting Method for Aging Reservoir Reinforce According to the Change of Binder and Using Water (결합재 및 사용수 변화에 따른 노후저수지 보강용약액주입공법 적용에 관한 연구)

  • Song, Sang-Hwon;Seo, Se-Gwan
    • Journal of the Korean Institute of Rural Architecture
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    • v.21 no.4
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    • pp.45-52
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    • 2019
  • Chemical grouting method is mainly used for construction of dams and reservoirs, stabilization and reinforcement of slopes, reinforcement of soft grounds such as embankments, dredging and landfills, the order of earthquake response method, and the reinforcement of structures. Recently, it is widely applied in construction sites such as highways, airfields, high-speed railways, subsea facilities, port construction works, tunnels, and subway works. As such, the demand for grouting continues to increase. The development of the grouting method was focused on increasing the strength of the ground, and the development of the chemical additives, the injection device, and the stirring device were mainly performed. But ordinary portland cement used for grouting is a product that consumes natural resources such as limestone, generates a large amount of greenhouse gases, consumes a large amount of energy sources, and it is time to develop products and new methods to replace them. In this study, Ordinary Portland Cement and New Grouting Binder (circulating fluidized bed boiler fly and blast furnace slag) were compared and analyzed by the following test. Homo-gel strength and homo-gel time, water quality analysis of the water used and soil contamination process tests of homo-gel samples were performed. In the case of NGB, when Using water is used as the reservoir water, the strength measured smaller than that of the other water. However, it shows about 2.5 times greater than the homo-gel compressive strength applied to OPC (7-day, reservoir water), so there is no problem with water quality when applied.

The Jurisprudence on Anti-Doping Rule Violation through Review of CAS Awards (CAS의 결정례로 본 도핑 위반 사건의 법리)

  • Kim, Hyun-Sook
    • Journal of Arbitration Studies
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    • v.28 no.1
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    • pp.77-97
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    • 2018
  • The Court of Arbitration for Sport (CAS) has been adjudicating on sports-related disputes since 1984. CAS can be regarded as world supreme court for sports settling down about 4200 cases including doping issues. Doping disputes are generally processed by CAS Appeals division and Anti-Doping Division. An appeal against the decision by sports-related bodies may be filed with CAS Appeals Division. Doping issues concerning Olympic games are on Anti-Doping Division, introduced from 2016 Olympic games and invested with complete authority by IOC. The Award of Maria Sharapova finds a player is responsible if found to have committed any Anti-Doping Rule Violation regardless of his/her intention or fault. It offers detailed jurisprudence on imposing such a specific period of ineligibility in view of the totality of the circumstances. The award of Xinyi Chen also confirms the Strict Liability Rule on anti-doping disputes. The player appealed there could be either accidental contamination of drinks, or doping laboratories' mistakes that affected the test results. But, all of them were rejected. Though dealing with doping disputes in a timely manner is important for seasonal sports events like Olympic games, it is necessary to prepare the acceptable and fair process for the players in the future.

Risk Assessment for Retrofitting an Electrolysis Type Ballast Water Treatment System on an Exiting Vessel (현존선에 전기분해방식 선박평형수 처리장치 설치를 위한 위험도 평가 분석)

  • JEE, Jae-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.665-676
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    • 2017
  • Over the past several years, sea trade have increased traffic by ships which highlighted a problem of unwanted species invading the surrounding seas through ship's ballast water discharge. Maritime trade volume has continuously increased worldwide and the problem still exists. The respective countries are spending billions of dollars in an effort to clean up the contamination and prevent pollution. As part of an effort to solve marine environmental problem, BWM(Ballast Water Management) convention was adopted at a diplomatic conference on Feb. 13 2004. In order to comply harmoniously this convention by each country. This convention will be effective after 12 months from the date which 30 countries ratified accounting for more than 35% of the world merchant shipping volume. On Sep. 8 2016, Finland ratified this convention and effective condition was satisfied as 52 states and world merchant vessel fleet 35.1441%. Thus, after Sep. 8 2017, all existing vessels shall be equipped with BWTS(Ballast Water Treatment System) in accordance with D-2 Regulation, which physically handles ballast water from ballast water exchange system(D-1 Regulation). In this study, we analyzed in detail the optimal design method using the Risk Analysis and Evaluation technique which is mainly used in the manufacturing factory or the risky work site comparing with the traditional design concept method applying various criteria. The Risk Assessment Method is a series of processes for finding the Risk Factors in the design process, analyzing a probility of the accident and size of the accident and then quantifying the Risk Incidence and finally taking measures. In this study, this method was carried out for Electrolysis treatment type on DWT 180K Bulk Carrier using "HAZOP Study" method among various methods. In the Electrolysis type, 63 hazardous elements were identified.

Simulation of Curved Surface Forming of Steel Plate by Induction Heating (유도 가열을 이용한 강판의 곡면 성형 시뮬레이션)

  • Ryu, Hyun-Su;Kim, Ho-Kyeong;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4381-4387
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    • 2015
  • Ship hull is a compound curved shape and most of shipyards have been using gas heating method for the surface forming of steel plate. This traditional forming process have problems such as difficulties in heat input control and poor working conditions due to loud noise and air contamination. Recently, researches on automatic hull forming system have been conducted using high frequency induction heating method which have good control ability and favorable working environment. In this study, the induction heating simulation system for curved surface forming of steel plate was developed and induction heating experiments were performed. Based on the results of this study, efficient induction heating coil design and optimal heating conditions for the automatic hull forming system can be obtained.

Field Application of Ultrasonic Inspection System for Stay Welds at Steam Generator of KSNP (한국표준형 원전 증기발생기 Stay 용접부 자동검사시스템 및 현장 검증)

  • Lim, Sa Hoe;Park, Chi Seung;Park, Chul Hoon;Joo, Keum Chong;Noh, Hee Chung;Yoon, Kwang Sik
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.6 no.1
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    • pp.37-42
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    • 2010
  • The stay cylinder weld at the steam generator of Korean Standard Nuclear Power Plants is safety class I component and is subjected to be inspected by the volumetric examination such as ultrasonic method. As accessibility of this area is limited due to the narrow space and high radiation, the existing manual inspection method involves various difficulties. Moreover operators may be exposed to internal contamination by contaminated dust during the surface buffing process to improve the inspection reliability of this area. Recently the new automatic inspection system for stay cylinder welds has been developed. The inspection system basically consists of a driving assembly, data acquisition device and signal processing units. The driving assembly is classified by 1) the scanner for inspecting and buffing the weld, 2) pillars for guiding the scanner and 3) the base frame for loading and supporting pillars. The scanner has 4 sensor modules to inspect in 4 refracted angles and 4 incident directions. These components can be inserted into the skirt of the stay cylinder through the manway hole and assembled easily by one-touch in the skirt. Data acquisition device and signal processing units developed in previous works are also newly upgraded for better processing of data analysis and evaluation. The system has been successfully demonstrated not only in the mock-up but also in the field. In this paper, newly developed inspection system for the stay cylinder weld of the steam generator is introduced and their field applications are discussed.

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Development of ALARA Checklist for an ALARA Design Review (ALARA 설계검토를 위한 ALARA 점검표 개발)

  • Shin, Sang-Woon;Song, Myung-Jae
    • Journal of Radiation Protection and Research
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    • v.21 no.3
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    • pp.155-166
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    • 1996
  • All nuclear facilities and components should receive an initial ALARA review before the installation and thereafter whenever modifications are planned. A major objective in design aspects of ALARA is to identify areas where specific engineering input can reduce personnel exposure. The basic factors which should be considered in the ALARA design review process include curd control, shielding and isolation of radiation sources accessibility maintainability and reliability, and contamination control. Because many diverse aspects must be considered in the ALARA design reviews, a proper ALARA checklist should be used to aid the designer in preventing any of the ALARA review considerations from being slipped away. In order to develop the practical ALARA checklist, check items for basic ALARA factors have been prepared, and what should be considered in reviewing each item has been discussed here. Based on the proposed factors and items, an ALARA checklist was developed.

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Silicon wire array fabrication for energy device (실리콘 와이어 어레이 및 에너지 소자 응용)

  • Kim, Jae-Hyun;Baek, Seung-Ho;Kim, Kang-Pil;Woo, Sung-Ho;Lyu, Hong-Kun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.440-440
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    • 2009
  • Semiconductor nanowires offer exciting possibilities as components of solar cells and have already found applications as active elements in organic, dye-sensitized, quantum-dot sensitized, liquid-junction, and inorganic solid-state devices. Among many semiconductors, silicon is by far the dominant material used for worldwide photovoltaic energy conversion and solar cell manufacture. For silicon wire to be used for solar device, well aligned wire arrays need to be fabricated vertically or horizontally. Macroscopic silicon wire arrays suitable for photovoltaic applications have been commonly grown by the vapor-liquid-solid (VLS) process using metal catalysts such as Au, Ni, Pt, Cu. In the case, the impurity issues inside wire originated from metal catalyst are inevitable, leading to lowering the efficiency of solar cell. To escape from the problem, the wires of purity of wafer are the best for high efficiency of photovoltaic device. The fabrication of wire arrays by the electrochemical etching of silicon wafer with photolithography can solve the contamination of metal catalyst. In this presentation, we introduce silicon wire arrays by electrochemical etching method and then fabrication methods of radial p-n junction wire array solar cell and the various merits compared with conventional silicon solar cells.

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Development of V-SAM Process and Surface Characterization for Anti-contamination of CMP Conditioner (CMP Conditioner의 오염방지를 위한 V-SAM 공정개발과 박막특성 분석)

  • Kim, Dong-Chan;Kim, In-Kwon;Kim, Jeong;Chun, Jong-Sun;Park, Mun-Seak;Park, Jin-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.56-56
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    • 2009
  • 반도체 device가 점점 고집적화, 다층화 되면서 막질의 평탄화를 위한 CMP (chemical mechanical planarization) 공정은 반도체 제작 공정에서 필수 요건이 되었다. 특히 pad conditioning은 CMP 공정 중, 막질의 제거율과 균일도를 유지시키기 위한 중요한 공정이다. 하지만, conditioner를 장시간 사용할 경우 slurry residue와 같은 잔류 오염물질들이 conditioner의 표면의 오염을 유발할 수 있고 이로 인해 conditioner의 수명이 단축되거나 웨이퍼 표면에 결함을 유발할 수도 있다. 본 연구에서는 이를 방지하기 위해 vapor SAM을 이용하여 Ni conditioner 표면에 소수성 박막을 증착하여 오염여부를 평가해 보았다. 먼저, Ni wafer를 이용하여 증착 온도와 압력에 따라 소수성 박막을 증착하여 표면특성을 평가해 보았다. 증착전과 후에 Ni wafer 표면의 접촉각은 contact angle analyzer (Phoenix 400, SEO, Korea)를 이용하여 측정하였다. 박막 표면 형상과 거칠기는 AFM (XE-100, PSIA, Korea)를 이용하여 평가되었고 묘면 성분 분석을 위해 FT-IR (Nicolet 6700, Thermo Scientific, USA)이 사용되었다. SEM (S-4800, Hitach, Japan)은 박막 증착 전과 후의 conditioner를 이용하여 실제 conditioning후 conditioner 표면의 particle 오염정도를 관찰하기 위해 사용되었다. 또한, conditioner 표면에 실제 오염되어있는 particle 개수를 평가하기 위해 particle size analyzer (Accusizer 780A, Particle Sizing Systems Co., USA)을 사용하였다. 본 실험을 통해 최적 증착 조건을 확립하였으며 실제 conditioner 표면에 소수성 박막을 증착 후 $100^{\circ}$ 이상의 높은 contact angle을 확인할 수 있었다. 또한, 소수성 박막이 증착된 conditioner의 경우 실제 conditioning후 표면 particle 오염이 현저히 감소되었음을 확인할 수 있었다.

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Evaluation of Microleakage with Retrograde Filling Materials in Blood Contamination (혈액 오염된 역충전 재료의 미세누출 평가)

  • Cho, Hye-Jin;Moon, Jhong-Hyun;Chon, Seong-Min;Yu, Mi-Kyung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.1
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    • pp.85-93
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    • 2007
  • The purpose of this study was to evaluate the microleakage of root-end filling material filled in blood contaminated root-end cavity and self-etching adhesive placed over blood contaminated resected root apices without root-end preparation. Extracted, human maxillary incisors, canines and mandibular premolar were randomly divided into four groups of 15 teeth each. After canal preparation, resection of the apex and root-end preparation, MTA and IRM were filled in the root-end cavity (A and B group). After canal preparation and resection of the apex, Clearfil SE Bond and Prompt L-Pop were applied over the contaminated root-end surfaces (C and D group). The roots were then subjected to 15cm of water pressure to simulate periapical microleakage stress. Data were analyzed using one-way ANOVA. The results were as follows : 1. All groups showed a tendency of decreasing microleakage in process of time after 2weeks later except IRM group. 2. After 2 weeks and 1 month, MTA group showed less microleakage significantly than other groups(p<0.05). After 2 months, Prompt L-Pop group showed less microleakage significantly than other groups(p<0.05). 3. After 9 months, there were no significant differences among four groups(p>0.05). Thus it is considered that apical sealing using adhesives system without root-end preparation is good method in endodontic surgery.

Characterization of Bacteria and Their Antibiotic Sensitivities in Porcine Liquid Semen (돼지 액상정액 내 세균오염과 항생제 감수성에 관한 연구)

  • Ryu, Jae-Weon;Cho, Kyu-Ho;Hong, Joon-Ki;Kim, Myung-Jick;Park, Jun-Chul;Jung, Il-Byung;Kim, In-Cheul
    • Journal of Animal Science and Technology
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    • v.50 no.6
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    • pp.793-798
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    • 2008
  • The semen collection process in the porcine is far from being a sterile procedure. Consequently, porcine ejaculates commonly contain bacterial contaminants. The aim of this study is to identify the bacteria in porcine semen and to find the antibiotics resistance of bacteria. Twelve porcine originating from four AI center were used to collect semen. Bacteria were identified by automated instrument for rapid organism identification system and bacterial sensitivities of 8 antibiotics were tested. The Bacterial contaminants of Staphylococcus genus(37.8%), Proteus genus(7.0%), Bacillus genus (6.1%), Pasteulla genus(5.7%), Acinetobacte genus(5.2%), Serratia genus(4.3%) and others(33.9%) were frequently isolated. However, amikacin showed higher antibiotic sensitivity than other antibiotics. General sanitation protocols can contribute partly to inhibit the bacterial contamination, with monitoring boar housing, semen collection areas and the extended semen. But, proper selection of preservative antibiotics by microbial sensitivities can minimize the influence of bacteria.