• Title/Summary/Keyword: 2 Stage Valve

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Assessment of radiographic left atrial dimension and C-reactive protein in dogs with myxomatous mitral valve disease

  • Jihee Hong;Han-Joon Lee;Dong-Kwan Lee;Kun-Ho Song
    • Korean Journal of Veterinary Service
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    • v.47 no.1
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    • pp.1-7
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    • 2024
  • Radiographic left atrial dimension (RLAD) is a valuable metric for assessing left atrial enlargement in dogs. While there have been studies on the use of RLAD and the increase in C-reactive protein (CRP) levels based on heart disease stages, there has been no prior research on the correlation between RLAD and CRP. In this study, the objective was to investigate the relationship between the rise in RLAD as myxomatous mitral valve disease (MMVD) stages advance and the increase in CRP levels with MMVD stage progression. In this study, a total of 30 small-breed dogs were included as subjects. These dogs were diagnosed with MMVD at the American College of Veterinary Internal Medicine (ACVIM) stage B1 or B2, or stage C, based on a comprehensive assessment including physical examination, thoracic radiography, and echocardiography. Measurements of VHS and RLAD were compared to assess any significant differences. There were significant differences in RLAD between dogs with MMVD ACVIM stage B1 and those with stage C. The monocytes and CRP levels showed significant differences between ACVIM stage B1, B2 and ACVIM C. Additionally, a significant correlation was observed between the RLAD and VHS measurements. This underscores the notable association between MMVD stage advancement and elevated monocyte and CRP levels. The RLAD scores exhibited a significant difference among dogs with ACVIM stages B1, B2, and C, and significant variations were also observed in monocyte and CRP levels. These results suggest that monocyte and CRP levels may be a valuable diagnostic indicator for heart disease in dogs during the diagnostic evaluation.

Finite Element Analysis and Process Planning about the Auto Transmission Solenoid Valve using of Multi-Former (다단-포머를 이용한 오토트랜스 미션용 솔레노이드 밸브 공정설계 및 유한요소해석)

  • Park, Chul-Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.1
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    • pp.97-103
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    • 2009
  • The process design of forward Extrusion and Upsetting of Axi-symmetric part has been studied in this paper. During the cold forging product; auto transmission Solenoid Valve part, the defects such as folding and under-fill can be appeared by the improperly controlled metal flow. In this study, to reduce the folding and under-fill the design of experiments has been used to find out the significant design variables in the design of forging process. This paper deals with an Process Planning with which designer can determine operation sequences even after only a little experience in Process Planning of Multi-Former products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge-base consisting of design rules is built. Based on the systematic procedure of process sequence design, the forming operation of cold forged auto transmission Solenoid Valve part is analyzed by the commercial Finite Element program, DEFORM/2D.

Numerical Study on the Waterhammer of PalDang Intake Pumping Station (팔당 취수펌프장의 수격현상에 관한 수치해석적 연구)

  • Kim, Kyung-Yup;Yu, Teak-In
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.4 s.9
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    • pp.52-58
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    • 2000
  • The numerical study on the waterhammer was carried out for the intake pumping station of the metropolitan water supply 6th stage project. Because the waterhammer problems as a result of the pump power failure were the most important, these situations were carefully investigated. The surge tank and the stand pipes effectively protected the tunnels md the downstream region of pipeline from the pressure surge. In case the moment of inertia of the pump and motor was above $5080\;kg{\cdot}m^2$, the column separation did not occur in the pipeline between the pumping station and the inlet of 1st tunnel. As the moment of inertia increased, the pressure surges decreased in the pipeline conveying raw water. The pump control valve was chosen as the main surge suppression device for the intake pumping station. After power failure, the valve disc should be rapidly closed in 2.5 seconds and controlled the final closure to 15 seconds by the oil dashpot. If the slamming happened to the pump control valve, there was some danger of this system damaging. As the reverse flow through the valve increased, the upsurge extremely increased.

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Development and Verification of Analytical Model of a Main Control Valve (메인 컨트롤밸브의 해석모델 개발 및 검증)

  • Kim, D.M.;Lee, J.M.;Jung, W.J.;Jang, J.S.
    • Journal of Drive and Control
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    • v.12 no.2
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    • pp.39-48
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    • 2015
  • In order to control the actuators of hydraulic machinery such as excavators, various control valves are typically assembled in a single block. Such a control block is called a main control valve(MCV). In this paper, we analyzed the working principle and the particular purpose of the design of all valves included in the MCV system. To Examine the reliability of the analysis model, the pressure drop of the MCV at each port was measured. The authors developed an analytical model of the control valve(main spool, load poppet, pressure relief, make up, and regeneration). The authors considered the notch shape of the spool while developing the analytical models of the main spool valve. Most importantly, at the stage before the analysis model was applied in the design tuning, the reliability was ensured by comparing the analysis results with the test results. This paper showed a process of developing an analysis model that can be utilized in the design and tuning stages.

Valve Replacement in a Patient with Chronic Renal Failure -a Case Report- (만성 신부전 환자에서의 판막치환술 1례 보고)

  • 구본일
    • Journal of Chest Surgery
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    • v.21 no.2
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    • pp.347-350
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    • 1988
  • Recent advances in the managements of chronic renal failure have increased the number of the candidates for cardiac operation in patients with chronic renal disease. There have been reports that the operative mortality of the open cardiac surgery in patients with end stage renal diseases was equal to that of the patients with normal renal function. Aortic valve replacement and mitral annuloplasty was successfully performed in a patient with chronic renal failure, and the pre-and postoperative managements are presented.

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Non-Toxic Post Boost Stage Demonstration

  • Fukuchi, Apollo B.;Ooya, Koji;Harada, Osamu;Makino, Takashi;Matsuda, Seiji;Akiyama, Masao
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.437-441
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    • 2008
  • A non-toxic Post Boost Stage(PBS) with LOX/Ethanol engine was successfully demonstrated at the Tomioka Facility of IHI Aerospace. IHI Aerospace has researched and developed the nontoxic propulsion systems and the LOX/Ethanol is one of the most attractive non-toxic bipropellant candidates. ${\rho}ISP$ of LOX/Ethanol is higher than ${\rho}ISP$ of the other non-toxic bipropellants as LOX/HC or $LOX/LH_2$. The authors studied the combustion characteristics of LOX/Ethanol propellant with the engine designed for LOX/LNG propellant. Also the injector with a built-in igniter was designed and examined its feasibility, ignition and combustion characteristics. We have demonstrated Post Boost Stage with future LOX/Ethanol engines. This propulsion system is targeted for expandable vehicle upper stage to accelerate delta-V to reach the required orbit. PBS Demonstration Model is designed as a test stand to evaluate feed system for integrated propulsion system and also to demonstrate Integrated Vehicle Health Management(IVHM) technique using local valve control and also valve behavior-monitoring capability.

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A case of Sotos syndrome presented with end-stage renal disease due to the posterior urethral valve

  • Cho, Won Im;Ko, Jung Min;Kang, Hee Gyung;Ha, Il-Soo;Cheong, Hae Il
    • Journal of Genetic Medicine
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    • v.11 no.2
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    • pp.74-78
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    • 2014
  • Sotos syndrome (SS, OMIM 117550) is characterized by prenatal and postnatal overgrowth with multiple congenital anomalies. However, there have been few cases of growth retardation caused by renal failure from infancy. We report a case of dysplasia of the bilateral kidneys with renal failure and poor postnatal growth. A 2-month-old boy visited the emergency room owing to poor oral intake and abdominal distension. He was born at the gestational age of 38 weeks with a birth weight of 4,180 g. After birth, he had feeding difficulty and abdominal distension. Upon physical examination, his height and weight were in less than the 3rd percentile, while his head circumference was in the 50th percentile on the growth curve. He also showed a broad and protruding forehead and high hairline. Blood laboratory tests showed severe azotemia; emergent hemodialysis was needed. Abdominal ultrasonography revealed bilateral renal dysplasia with multiple cysts and diffuse bladder wall thickening. A posterior urethral valve was suggested based on vesicoureterography and abdominal magnetic resonance findings. Results of a colon study to rule out congenital megacolon did not reveal any specific findings. The conventional karyotype of the patient was 46, XY. Array comparative genomic hybridization study revealed a chromosome 5q35 microdeletion including the NSD1 gene, based on which SS was diagnosed. We describe a case of SS presenting with end stage renal disease due to posterior urethral valve. The typical somatic overgrowth of SS in the postnatal period was not observed due to chronic renal failure that started in the neonatal period.

Incomplete Form of Shone Complex in an Adult Congenital Heart Disease Patient

  • Shih, Beatrice Chia-Hui;Lim, Jae Hong;Min, Jooncheol;Kim, Eung Re;Kwak, Jae Gun;Kim, Woong-Han
    • Journal of Chest Surgery
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    • v.52 no.2
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    • pp.100-104
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    • 2019
  • Shone complex is a rare congenital disorder that involves 4 obstructive lesions of the left heart, as follows: parachute mitral valve, supravalvular mitral ring, subaortic stenosis, and coarctation of the aorta. Incomplete forms with 2 or 3 of these lesions in adult patients have been rarely reported in the literature, meaning that insufficient general data exist concerning the surgical strategy and clinical follow-up. Herein, we report the case of a 31-year-old woman with a diagnosis of incomplete form of Shone complex with parachute mitral valve and coarctation of the aorta who underwent successful single-stage surgical repair.

PID Controller and Derivative-feedback Gain Design of the Direct-drive Servo Valve Using the Root Locus and Manual Tuning (근궤적과 수동 조정에 의한 직접 구동형 서보밸브의 PID 제어기 및 미분피드백 이득 설계)

  • Lee, Seong Rae
    • Journal of Drive and Control
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    • v.13 no.3
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    • pp.15-23
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    • 2016
  • The direct-drive servo valve(DDV) is a kind of one-stage valve because the main spool valve is directly driven by the dc motor. Since the DDV structure is simple, it is less expensive, more reliable, and offers a reduced internal leakage and a reduced sensitivity to fluid contamination. The control system of the DDV is highly nonlinear due to a current limiter, a voltage limiter, and the flow-force effect on the spool motion. The shape of the step response of the DDV-control system varies considerably according to the magnitudes of the step input and the load pressure. The system-design requirements mean that the overshoots should be less than 20%, and the errors at 0.02s should be less than 2%, regardless of the reference-step input sizes of 1V and 5V and the load-pressure magnitudes of 0MPa and 20.7MPa. To satisfy the system-design requirements, the PID-controller parameters of $K_c$, $T_i$ and $T_d$, and the derivative-feedback gain of $K_{der}$ are designed using the root locus and manual tuning.

Pressure Regulator for Piezoelectric Valve (압전 밸브용 압력 레귤레이터)

  • Yun, S.N.;Kim, C.Y.;Seo, S.W.;Park, J.H.;Ham, Y.B.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.3 no.2
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    • pp.1-6
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    • 2006
  • The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 lpm, maximum operating pressure of 0.9MPa and frequency characteristic of 10Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9MPa directly. In this study, bimorph type PZT actuator of $25.2mm(L){\times}7.2mm(W){\times}0.5mm(H)$ with constant of $-220{\times}10-12$ CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of $63{\mu}m$ were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator.

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