• Title/Summary/Keyword: Emerging Technology

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Investigation of dust particle removal efficiency of self-priming venturi scrubber using computational fluid dynamics

  • Ahmed, Sarim;Mohsin, Hassan;Qureshi, Kamran;Shah, Ajmal;Siddique, Waseem;Waheed, Khalid;Irfan, Naseem;Ahmad, Masroor;Farooq, Amjad
    • Nuclear Engineering and Technology
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    • v.50 no.5
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    • pp.665-672
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    • 2018

  • A venturi scrubber is an important element of Filtered Containment Venting System (FCVS) for the removal of aerosols in contaminated air. The present work involves computational fluid dynamics (CFD) study of dust particle removal efficiency of a venturi scrubber operating in self-priming mode using ANSYS CFX. Titanium oxide ($TiO_2$) particles having sizes of 1 micron have been taken as dust particles. CFD methodology to simulate the venturi scrubber has been first developed. The cascade atomization and breakup (CAB) model has been used to predict deformation of water droplets, whereas the Eulerian-Lagrangian approach has been used to handle multiphase flow involving air, dust, and water. The developed methodology has been applied to simulate venturi scrubber geometry taken from the literature. Dust particle removal efficiency has been calculated for forced feed operation of venturi scrubber and found to be in good agreement with the results available in the literature. In the second part, venturi scrubber along with a tank has been modeled in CFX, and transient simulations have been performed to study self-priming phenomenon. Self-priming has been observed by plotting the velocity vector fields of water. Suction of water in the venturi scrubber occurred due to the difference between static pressure in the venturi scrubber and the hydrostatic pressure of water inside the tank. Dust particle removal efficiency has been calculated for inlet air velocities of 1 m/s and 3 m/s. It has been observed that removal efficiency is higher in case of higher inlet air velocity.

  • https://doi.org/10.1016/j.net.2018.01.016 인용 PDF KSCI

General-purpose Transaction Management Technique for Data Stability of NoSQL on Distributed File System (분산 파일 시스템 기반 NoSQL의 데이터 안정성을 위한 범용 트랜잭션 관리 기법)

  • Kwon, Younghyun;Yun, Do-hyun;Park, Hojin
    • Journal of Digital Contents Society
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    • v.16 no.2
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    • pp.299-306
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    • 2015

  • In this paper, we research to secure stability of data storing/searching on NoSQL implemented on Distributed File System. When implementing NoSQL on Distributed File System, we faced that random write on Distributed File System is almost impossible. To solve this problem, a concept of Intermediate-File was employed, and then it has been achieved that our system resist any failure circumstance. Additionally, since we discovered its performance cannot be as fast as general File System, by redefining the file block unit for our NoSQL system, we have prevented a slowdown in system performance. As a result, we are able to develop highly scalable NoSQL as Distributed File System, which fulfills basic conditions of transaction: Atomicity, Consistency, Isolation, and Performance.

  • https://doi.org/10.9728/dcs.2015.16.2.299 인용 PDF KSCI

Risk Assessment of Micro and Emerging Contaminants in Domestic Effluent Environment: Targeting on 80 First-class substances assigned by Ministry of Environment (미량 및 신종유해물질의 국내 방류 환경에서의 위해성 평가: 환경부 지정 1순위 80종 대상으로)

  • Lee, Jai-Yeop;Park, Saerom;Kim, Ilho
    • Journal of Korean Society on Water Environment
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    • v.37 no.6
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    • pp.501-509
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    • 2021

  • In 2018, total 263 micro and emerging contaminants were selected as target substances by the Ministry of Environment, and 80 of them were first-class substance including endocrine disruptors, residual Pharmaceuticals and Personal Care Products (PPCPs), residual organic pollutants, pesticides and heavy metals. In this study, in order to evaluate the Hazard Quotient (HQ) of the 80 types in the domestic water environment the concentration of discharged effluent and nearby water environment reported by Korean institutes since 2010 was investigated. There were 45 substances reported to be detected, and Measurement Environment Concentration (MEC) were obtained by collectively converting them into water environment concentration. For biotoxicity, half maximal Effective Dose (EC50) to Daphnia magna, a water fleas species widely adopted in Material Safety Data Sheet (MSDS) was applied. As for the biotoxicity level, the Predicted No-Effect Concentration (PNEC) was obtained by applying the Assessment Factor (AF) and the HQ was derived by dividing it from the MEC. As a result of calculating the HQ, more than 1 substances were Cabamazepine, Mefenamic acid, Acetaminophen, Ibuprofen, Nonylphenol, Nickel, Erythromycin, Acetylslic acid, etc. Meanwhile, perfluorinated compounds were identified as hazardous substances in the water env ironment, with 5 out of 14 species included in the 20 ranks of first-class substance.

  • https://doi.org/10.15681/KSWE.2021.37.6.501 인용 PDF KSCI