• 제목/요약/키워드: TCV

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A Study on the Performance Improvement of Pressure Compensating Temperature Control Valve (압력 평형식 온도조절 밸브 성능 향상을 위한 연구)

  • Kim T.-A.;Kim Youn J.
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.671-674
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    • 2002
  • Pressure compensating temperature control valve(TCV) is one of the important control devices, which is used to maintain the constant temperature of working fluid in power and chemical plants. The ratio of cylinder hole diameters of inlet and outlet is the main design parameters of TCV. So this needs to be investigated to improve the function of control of temperature and void fraction. In this study, numerical analysis is carried out with various ratios of cylinder hole diameters of the inlet and outlet in the TCV. Especial1y, the distribution of the static pressure Is investigated to calculate the new coefficient($C_{\upsilon}$) and resistance coefficient(K). The governing equations are derived from making using of three-dimensional Naver-Stokes equations with standard $k-{\varepsilon}$ turbulence model and SIMPLE algorithm. Using a commercial code, PHOENICS, pressure and flow fields in TCV are calculated with different inlet and outlet diameters of the cylinder hole for cold and hot water passages.

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HRT-mediated Turnip crinkle virus Resistance in Arabidopsis

  • Park, Jeong-Mee;Daniel F. Klessig
    • The Plant Pathology Journal
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    • v.19 no.1
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    • pp.19-23
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    • 2003
  • Turnip crinkle vims (TCV) inoculation onto resistant Arabidopsis ecotype Dijon(Di-17) leads to a hypersensitive response (HR) on the inoculated leaves. A dominant gene, HRT, which confers an HR to TCV, has been cloned from Di-17 plants by map-based cloning. HRT is a LZ-NBS-LRR class resistance gene and it belongs to a small gene family that includes RPP8, which confers resistance to Peronospora parasitica Emco5. Outside of the LRR region, HRT and RPP8 proteins share 98% amino acid identity while their LRR regions are less conserved (87% identity). HRT-transformed Arabidopsis plants developed an HR but generally remained susceptible to TCV due to a dominant RRT allele, which is not compatible with resistance. However, several transgenic plants that over-expressed HRT much higher than Di-l7 showed micro-HR or no HR when inoculated with TCV and were resistant to infection. Both the HR and resistance are dependent on salicylic acid but independent of NPRI, ethylene, or jasmonic acid. Arabidopsis plants containing both TCV coat protein gene and HRT developed massive necrosis and death in seedlings, indicating that the TCV coat protein is an avirulence factor detected by the HRT.

A Numerical Study on the Flow Characteristics of Temperature Control Valve by Pressure Compensation (압력 평형식 온도조절 밸브 내부 유동 특성에 대한 수치적 연구)

  • Hwang, J.H.;Kim, T.A.;Kim, Youn-J.
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.448-453
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    • 2005
  • Temperature Control Valve (TCV) is one of the useful temperature control devices, which is used to control constant temperature of working fluid in power and chemical plants and domestic water supply systems. TCV is composed of body, cylinder and piston, and the body shape has a symmetrical H-type. In general, it has several inlet and outlet holes, and its shape is like as tubular sleeve. The piston has three rings two rings of the end of piston have the function of controlling inlet flow rate with hot and cold working fluids, the center ring has the function of preventing hot and cold water from intermixing. Consequently, the shapes of piston and cylinder are the main design parameters in the performance of TCV. In this study, numerical analyses were carried out with two different piston and cylinder shapes to investigate the functions as a temperature control valve and the flow characteristics according to piston opening grade in TCV. Using a commercial code, FLUENT, velocity and pressure fields in TCV are obtained under steady, standard $k -{\epsilon}$ turbulence model and no-slip condition.

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A study on the flow charateristics of temperature control valve by pressure compensation (압력 평형식 온도 조절 밸브의 유동특성 연구)

  • Kim, T.-A.;Kim, Youn J.
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.419-424
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    • 2001
  • TCV(Temperature control valve by pressure compensation) controls temperature constantly, when it is sending steam or high temperature water to heating device of heat exchanger. For designing TCV, the ratio of piston and hole diameters is one of the important design parameters. Numerical analysis is carried out to elucidate the flow characteristics in the TCV with different port areas of cold and hot waters, using the k-$\epsilon$ turbulence model and Cartesian cut-cell method. Numerical results show that the exit flow rate is mainly affected by pressure distribution in the piston.

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A Study on Analysis of Intake Flow in a 5-valves Gasoline Engine by using a Two Color PIV System (이색 PIV를 이용한 5밸브 가솔린 엔진의 흡입 유동 해석)

  • Woo, Young-Wan;Park, Sang-Chan;Lee, Ki-Hyung;Lee, Chang-Sik
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.933-938
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    • 2001
  • A 5-valve(intake 3-valve) engine has been developed to increase engine performance. These vehicles have a high power caused by the decrease of inertia mass of an intake valve and the increase of intake effective area. In this study, velocity profiles at near intake valves were inspected by using a two-color PIV and laser sheet method with tumble control valve(TCV). In addition, steady flow tests were performed to quantify tumble ratio on flow-fields generated with a TCV. These experimental results show that the tendency of the tunble ratio in intake 3-valve engine is different from the one in intake 2-valve engine. From this results, the intake flow characteristics around intake valves were made clear.

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Estimation of Gasification Performance and Slag System Capacity for 300MW IGCC Plant (300MW IGCC 가스화플랜트의 가스화 성능 및 Slag System 용량 예측)

  • Koo, Ja-Hyung;Paek, Min-Su;Yoo, Jeong-Seok;Kim, Bong-Keun;Kim, You-Seok;Lee, Hwang-Jik
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.234-237
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    • 2008
  • 분류층 가스화기에서 가스화기 운전 온도는 슬래그의 원활한 배출과 가스화기 성능 등에 영향을 미친다. 가스화기 운전온도는 또한, 석탄 및 산소 소비량에도 영향을 미쳐 궁극적으로는 가스화 플랜트의 주요 설비 용량을 결정하는 주요 요인중의 하나이다. 가스화기 운전 온도가 일정수준 이상으로 증가할 경우 냉가스 효율이 저하되고 가스화 성능에 약 영향을 미친다. 본 논문에서는 Coal 및 Flux 공급장치, 슬래그 배출장치 당의 구성을 설명하고 Flux 투입량에 따른 슬래그 Tcv, 가스화기 성능 등을 예측하였다. 또한, 300MW IGCC 실증 가스화플랜트 엔지니어링을 위한 예비단계로 석회석 투입에 따른 Flux 공급장치를 포함한 Feeding 설비 용량, 슬래그처리설비 용량, 가스화기 내부 및 출구 적정온도를 예측하였다.

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The coat protein of Turnip crinkle virus is required a full-length to maintain suppressing activity to RNA silencing but no relation with eliciting resistance by N-terminal region in Arabidopsis.

  • Park, Chang-Won;Feng Qu;Tao Ren;T. Jack Morris
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.76.1-76
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    • 2003
  • The coat protein (CP) of Turnip crinkle virus (TCV) is organized into 3 distinct domains, R domain (RNA-binding) connected by an arm, 5 domain and P domain. We have previously shown that the CP of TCV strongly suppresses RNA silencing, and have mapped N-terminal R domain of which is also the elicitor of resistance response in the Arabidopsis ecotype Di-17 carrying the HRT resistance gene. In order to map the region in the TCV CP that is responsible for silencing suppression, a series of CP mutants were constructed, transformed into Agrobacterium, coinfiltrated either with HC-Pro (the helper component proteinase of tobacco etch potyvirus) known as a suppressor of PTGS or GFP constructs into leaves of Nicotiana benthmiana expressing GFP transgenically. In the presence of HC-Pro, all CP mutants were well protected, accumulating mutant CP mRNAs and their proteins even 5 days post-infiltration (DPI). In the presence of GFP, some mutant constructs which showed the accumulation of CP mutants and GFP mRNAs at early stage but eventually degraded at 5 DPI. Only a mutant which carrying 4 amino acid deletion of R domain was tolerable to maintain suppressing activity, suggesting that the suppressing activity is not directly related with the eliciting activity. A transient assay also revealed that the mutants synthesized their proteins, suggesting that a full length of CP sequences and its intact structure are required to stabilize CP, which suppresses the RNA silencing.

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Effect of Pelleting Treatment on Seed Germination in Adenophora triphylla (잔대 종자 펠렛처리가 종자 발아에 미치는 영향)

  • Im, Dong Hyeon;Nam, Joo Hee;Kim, Jong Hyuk;Lee, Min Ju;Rho, Il Rae
    • Korean Journal of Medicinal Crop Science
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    • v.28 no.2
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    • pp.128-135
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    • 2020
  • Background: Sowing seeds of Adenophora triphylla is known to be difficult owing to their small size and irregular seed shape. Therefore, this study was conducted to develop a seed pelleting technique to save labor during sowing. Methods and Results: To identify the optimal germination temperature for A. triphylla seeds, the temperature range was set from 17℃ to 32℃. Germination surveys were conducted in plastic greenhouse conditions in March, April, and May to determine the appropriate sowing time. The optimal germination temperature for A. triphylla seeds was 29℃ and May was the optimal sowing time in plastic greenhouse conditions. Covering materials for seed pelleting used talc (T), kaolin (K), calcium carbonate (C), and vermiculite (V). The pellet binder used agar (A), pectin, xanthan gum, polyvinyl alcohol (PVA), and sodium alginate (S). The best suited treatment mixture were the best suited in kaolin / calcium carbonate / vermiculite (KCV), talc / calcium carbonate / vermiculite (TCV) mixture treatment for covering material, and sodium alginate (S), agar (A) as pellet binder, respectively. The germination rate was the best in TCV mixed with S. Conclusion: The mixture of TCV (2 : 1 : 3) + 1.5% S (TCVS), was found to be the best pelleting materials for A. triphylla seeds, and seed pelleting can be labor-saving during sowing.

Effect of V2O3 and CaO Concentrations on the Viscosity of 5-Component Petcoke Slag (V2O3와 CaO의 농도에 따른 5-성분계 석유코크스 슬래그의 점도 변화)

  • Yang, Yoonjung;Oh, Myongsook S.
    • Applied Chemistry for Engineering
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    • v.31 no.6
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    • pp.688-696
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    • 2020
  • Petroleum coke (petcoke) is widely used, next to coal, as a gasification feedstock. In gasification processes, the viscosity of the ash and the formation of crystalline phases must be understood to ensure the continuous removal of slag. This study investigates the effect of CaO and V2O3 on petcoke slag viscosity. The viscosity of the molten slag was measured in the temperature range of 1100~1600 ℃ while varying the concentration of each component. The crystalline phases formed in a cooled slag were examined. The most slag samples tested in this study exhibited crystalline slag behavior. The increased CaO concentration resulted in a lower viscosity and a lower Tcv. The viscosity behavior changed from the glassy to crystalline slag and also showed a higher Tcv as the concentration of V2O3 increases. Most slag samples showed different crystalline phases from top to bottom. Anorthites and Ca-V phases were observed in the top and middle section, while the bottom section mainly showed V2O3 and anorthite. The vanadium in the ash forms Ca-V and V-Fe phases and also remains in molten slag. A low melting Ca-V phase can contribute to lowering the viscosity.

DNA Damage Triggers the Activation of Immune Response to Viral Pathogens via Salicylic Acid in Plants

  • Hwi-Won Jeong;Tae Ho Ryu;Hyo-Jeong Lee;Kook-Hyung Kim;Rae-Dong Jeong
    • The Plant Pathology Journal
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    • v.39 no.5
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    • pp.449-465
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    • 2023
  • Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense-and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.