• Title/Summary/Keyword: 2-phase model

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A Study on Development of Systematic Practical Education Model, Equipment Design and Application for Undergraduate linked with Employee Training on the Spot for Practical Engineering Empowerment (실천공학역량강화를 위한 학부와 재직자 교육의 체계적인 연계 모델 개발 및 장비 설계·적용에 대한 연구)

  • Lee, Woo-Young;Kim, Jin-Woo;Cho, Nam-Chae
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.3 no.2
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    • pp.136-141
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    • 2011
  • The current tendency on development and change of equipment system in the factory are overlapped with the specific field of the existing systems such as PLC, DCS and SCADA, and the limited portion of the systems in the specific field stands in their own field. Specially, systematic integration, inspection control system and manufacturing management system, management information system are getting closely linked and therefore we increasingly need the open system. Meeting the needs, manufacturing automated equipments in the factory overcoming the shortcomings of unlinked unit equipment recently are getting changed to the phase closely linking with other systems. The training systems for the university, however, have not kept up with the needs from the industry, in spite that fused complex function and performance are asked in the field. To solve the problems, we suggest that the training courses and the equipment designed for the undergraduate education.

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Storyboard Software Usage Frequency Ranking and Usability (스토리보드 소프트웨어의 사용빈도 순위와 사용성)

  • Lee, Doh-Soo;Kim, Jun-Kyo
    • The Journal of the Korea Contents Association
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    • v.10 no.7
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    • pp.159-168
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    • 2010
  • Due to the trend of shift to digitalization of the storyboard in 1990's, many a number of storyboard related softwares were born. With this change of trends, however, there was an undeniable lack of tangible data showing the advantage of such digitalization of the storyboard using software technology over conventional methods of doing the same job. In this study, therefore, we have selected the top five storyboard software suits in terms of their frequency in use and a sample group of 85 people to give an analysis on their usability. The result of this analysis revealed two underlying tendencies regarding this issue. Firstly, all of the five softwares selected lacked interactive presentational features, suggesting the directives for the next phase of software development. Secondly, our experiments in this study showed that the most prominent benefit of using the softwares is the higher efficacy in delivering necessary information through real-time based replays, rather than the digitalization of the contents themselves. We expect that the findings of our study would serve as a new model for future software enhancement for the developers. And for the users of such softwares, too, the findings of this study is expected to help them understand what kind of benefits they can expect as they use these storyboard softwares.

Numerical Simulation of Surface Tension-Dominant Multiphase Flows by Using Volume-Capturing Method and Unstructured Grid System (비정렬격자계와 체적포착법을 사용한 표면장력이 지배적인 다상유동 수치해석)

  • Myong, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.7
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    • pp.723-733
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    • 2011
  • A numerical method of the CSF(Continuum Surface Force) model is presented for the calculation of the surface tension force and implemented in an in-house solution code(PowerCFD). The present method(code) employs an unstructured cell-centered method based on a conservative pressure-based finite-volume method with volume capturing method(CICSAM) in a volume of fluid(VOF) scheme for phase interface capturing. The application of the present method to a 2-D liquid drop problem is illustrated by an equilibrium and nonequilibrium oscillating drop calculation. It is found that the present method simulates efficiently and accurately surface tension-dominant multiphase flows.

Recombinant Glargine Insulin Production Process Using Escherichia coli

  • Hwang, Hae-Gwang;Kim, Kwang-Jin;Lee, Se-Hoon;Kim, Chang-Kyu;Min, Cheol-Ki;Yun, Jung-Mi;Lee, Su Ui;Son, Young-Jin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.10
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    • pp.1781-1789
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    • 2016
  • Glargine insulin is a long-acting insulin analog that helps blood glucose maintenance in patients with diabetes. We constructed the pPT-GI vector to express prepeptide glargine insulin when transformed into Escherichia coli JM109. The transformed E. coli cells were cultured by fed-batch fermentation. The final dry cell mass was 18 g/l. The prepeptide glargine insulin was 38.52% of the total protein. It was expressed as an inclusion body and then refolded to recover the biological activity. To convert the prepeptide into glargine insulin, citraconylation and trypsin cleavage were performed. Using citraconylation, the yield of enzymatic conversion for glargine insulin increased by 3.2-fold compared with that without citraconylation. After the enzyme reaction, active glargine insulin was purified by two types of chromatography (ion-exchange chromatography and reverse-phase chromatography). We obtained recombinant human glargine insulin at 98.11% purity and verified that it is equal to the standard of human glargine insulin, based on High-performance liquid chromatography analysis and Matrix-assisted laser desorption/ionization Time-of-Flight Mass Spectrometry. We thus established a production process for high-purity recombinant human glargine insulin and a method to block Arg (B31)-insulin formation. This established process for recombinant human glargine insulin may be a model process for the production of other human insulin analogs.

Human Sexuality and Sexual Dysfunction (성(性)생활과 성기능장애)

  • Cho, Doo-Young
    • Korean Journal of Psychosomatic Medicine
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    • v.7 no.1
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    • pp.10-25
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    • 1999
  • Children above age of two are able to have sexual excitement, and they actively seek the pleasure actively or passively through touch and masturbation. In late $60_s$ and early $70_s$, Masters, obstetrician, and Johnson, social worker, illustrated four phases of human sexual responses, namely excitement, plateau, orgasmic and resolution phases in both sexes, and multiple orgasms in the female. Their treatment principles of sexual dysfunctions were largely based on behavioral model, introducing the concepts of sensate focus, dual therapy and sex education. Following Masters and Johnson, Kaplan, psychiatrist and psychoanalyst, in the early and mid-$70_s$ introduced new sex therapy which was based on the combination of analytically-oriented psychotherapy and behavior therapy, and classified sexual dysfunctions into three categories such as desire excitement and orgasmic phase disorders. Since $1980_s$ other medical fields joined the stream, putting the concentrated effort on the treatment of the impotence in the male. They have developed penile prosthesis, local injection therapy, and the administration of oral medications. Nowadays Sildenafil(Viagra) seems the best choice for the treatment of the impotence in the male.

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EFFECT OF VALVE TIMING AND LIFT ON FLOW AND MIXING CHARACTERISTICS OF A CAI ENGINE

  • Kim, J.N.;Kim, H.Y.;Yoon, S.S.;Sa, S.D.;Kim, W.T.
    • International Journal of Automotive Technology
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    • v.8 no.6
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    • pp.687-696
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    • 2007
  • To increase the reliability of auto-ignition in CAI engines, the thermodynamic properties of intake flow is often controlled using recycled exhaust gases, called internal EGR. Because of the internal EGR influence on the overall thermodynamic properties and mixing quality of the gases that affect the subsequent combustion behavior, optimizing the intake and exhaust valve timing for the EGR is important to achieve the reliable auto-ignition and high thermal efficiency. In the present study, fully 3D numerical simulations were carried out to predict the mixing characteristics and flow field inside the cylinder as a function of valve timing. The 3D unsteady Eulerian-Lagrangian two-phase model was used to account for the interaction between the intake air and remaining internal EGR during the under-lap operation while varying three major parameters: the intake valve(IV) and exhaust valve(EV) timings and intake valve lift(IVL). Computational results showed that the largest EVC retardation, as in A6, yielded the optimal mixing of both EGR and fuel. The IV timing had little effect on the mixing quality. However, the IV timing variation caused backflow from the cylinder to the intake port. With respect to reduction of heat loss due to backflow, the case in B6 was considered to present the optimal operating condition. With the variation of the intake valve lift, the A1 case yielded the minimum amount of backflow. The best mixing was delivered when the lift height was at a minimum of 2 mm.

Numerical Investigation of the Urea Melting and Heat Transfer Characteristics with Three Different Types of Coolant Heaters (냉각수 순환 방식 가열원 형상에 따른 요소수 해동 특성에 관한 수치적 연구)

  • Lee, Seung-Yeop;Kim, Man-Young;Lee, Chun-Hwan;Park, Yun-Beom
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.4
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    • pp.125-132
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    • 2012
  • Urea-SCR system, which converts nitrogen oxides to nitrogen and water in the presence of a reducing agent, usually AdBlue urea solution, is known as one of the powerful NOx reduction systems for mobile as well as stationary applications. For its consistent and reliable operation in mobile applications, such various problems as transient injection, ammonia slip, and freezing in cold weather have to be resolved. In this work, therefore, numerical study on three-dimensional unsteady heating problems were analyzed to understand the melting and heat transfer characteristics such as urea liquid volume fraction, temperature profiles and generated natural convection behavior in urea solution by using the commercial software Fluent 6.3. After validating by comparing numerical and experimental data with pure gallium melting phenomena, numerical experiment for urea melting is conducted with three different coolant heating models named CH1, 2, and 3, respectively. Finally, it can be found that the CH3 model, in which more coolant is concentrated on the lower part of the urea tank, has relatively better melting capability than others in terms of urea quantity of $1{\ell}$ for start-up schedule.

Fungal Growth and Manganese Peroxidase Production in a Deep Tray Solid-State Bioreactor, and In Vitro Decolorization of Poly R-478 by MnP

  • Zhao, Xinshan;Huang, Xianjun;Yao, Juntao;Zhou, Yue;Jia, Rong
    • Journal of Microbiology and Biotechnology
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    • v.25 no.6
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    • pp.803-813
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    • 2015
  • The growth of Irpex lacteus F17 and manganese peroxidase (MnP) production in a selfdesigned tray bioreactor, operating in solid-state conditions at a laboratory scale, were studied. The bioreactor was divided into three layers by three perforated trays. Agroindustrial residues were used both as the carrier of bound mycelia and as a nutrient medium for the growth of I. lacteus F17. The maximum biomass production in the bioreactor was detected at 60 h of fermentation, which was consistent with the CO2 releasing rate by the fungus. During the stationary phase of fungal growth, the maximum MnP activity was observed, reaching 950 U/l at 84 h. Scanning electron microscopy images clearly showed the growth situation of mycelia on the support matrix. Furthermore, the MnP produced by I. lacteus F17 in the bioreactor was isolated and purified, and the internal peptide sequences were also identified with mass spectrometry. The optimal activity of the enzyme was detected at pH 7 and 25℃, with a long half-life time of 9 days. In addition, the MnP exhibited significant stability within a broad pH range of 4-7 and at temperature up to 55℃. Besides this, the MnP showed the ability to decolorize the polymeric model dye Poly R-478 in vitro.

Arabidopsis thaliana as Bioindicator of Fungal VOCs in Indoor Air

  • Lee, Samantha;Hung, Richard;Yin, Guohua;Klich, Maren A.;Grimm, Casey;Bennett, Joan W.
    • Mycobiology
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    • v.44 no.3
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    • pp.162-170
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    • 2016
  • In this paper, we demonstrate the ability of Arabidopsis thaliana to detect different mixtures of volatile organic compounds (VOCs) emitted by the common indoor fungus, Aspergillus versicolor, and demonstrate the potential usage of the plant as a bioindicator to monitor fungal VOCs in indoor air. We evaluated the volatile production of Aspergillus versicolor strains SRRC 108 (NRRL 3449) and SRRC 2559 (ATCC 32662) grown on nutrient rich fungal medium, and grown under conditions to mimic the substrate encountered in the built environment where fungi would typically grow indoors (moist wallboard and ceiling tiles). Using headspace solid phase microextraction/gas chromatography-mass spectrometry, we analyzed VOC profiles of the two strains. The most abundant compound produced by both strains on all three media was 1-octen-3-ol. Strain SRRC 2559 made several terpenes not detected from strain SRRC 108. Using a split-plate bioassay, we grew Arabidopsis thaliana in a shared atmosphere with VOCs from the two strains of Aspergillus versicolor grown on yeast extract sucrose medium. The VOCs emitted by SRRC 2559 had an adverse impact on seed germination and plant growth. Chemical standards of individual VOCs from the Aspergillus versicolor mixture (2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, limonene, and ${\beta}-farnesene$), and ${\beta}-caryophyllene$ were tested one by one in seed germination and vegetative plant growth assays. The most inhibitory compound to both seed germination and plant growth was 1-octen-3-ol. Our data suggest that Arabidopsis is a useful model for monitoring indoor air quality as it is sensitive to naturally emitted fungal volatile mixtures as well as to chemical standards of individual compounds, and it exhibits relatively quick concentration- and duration-dependent responses.

Estimation of Emission Factor (Residual Rate) and Inventory of HFC-134a from Mobile Air Conditioners of Scrap Truck (폐트럭으로부터 온실가스 HFC-134a의 탈루배출계수와 인벤토리 산정에 대한 연구)

  • Kim, Eui-Kun;Kim, Seungdo;Kim, Hyerim;Lee, Young Phyo;Byun, Seokho;Lee, Dong Won
    • Journal of Environmental Science International
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    • v.22 no.9
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    • pp.1105-1113
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    • 2013
  • This paper attempted to estimate the emissions of HFC-134a from scrap truck as a result of measuring the residual quantities of HFC-134a in air conditioner of scrap truck. We measured the residual amounts in the scrap truck of 138 by applying commercial recover for refrigerants. The average residual rate(disposal-phase emission factor) is reported to be $44.3{\pm}3.3%$ within a confidence interval of 95%. Recent year model trucks exhibit the higher residual rates. Little variation, however, is observed in regard to vehicle size. The HFC-134a emission quantity from scrap truck in 2011 is estimated to be 55,908 $tCO_2$-eq that demonstrates 21.4% increase to compare with that in 2007. As the numbers of truck have increased dramatically during the last two decades, the emissions of HFC-134a from scrap truck would increase sharply in the next coming years. HFC-134a is a very high GWP greenhouse gas. therefore have to reduce the emissions from the scrap truck and need to find ways to recycle. The chemical compositions of refrigerants from scrap truck are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap truck could be reused as refrigerant.