• 대한의용생체공학회:의공학회지
• /
• 제28권6호
• /
• pp.768-776
• /
• 2007

A new type of the fluid circulation blood pressure simulator was proposed to enhance the blood pressure simulator used for the development and evaluation of automatic sphygmomanometers. Various pressure waveform of fluid flowing in the pipe was reproduced by operating the proportional control valve after applying a pressure on the fluid in pressurized oil tank. After that, appropriate fluid was supplied by operating the proportional control valve, which enabled to reproduce various pressure wave of the fluid flowing in the tube. To accomplish this work, the mathematical model was carefully reviewed in cooperating with the proposed simulator. After modeling the driving signal as input signal and the pressure in internal tube as output signal, the simulation on system parameters such as internal volume, cross-section of orifice and supply pressure, which are sensitive to dynamic characteristic of system, was accomplished. System parameters affecting the dynamic characteristic were analyzed in the frequency bandwidth and also reflected to the design of the plant. The performance evaluator of fluid dynamic characteristic using proportional control signal was fabricated on the basis of obtained simulation result. An experimental apparatus was set-up and measurements on the dynamic characteristic, nonlinearity, and rising and falling response was carried out to verify the characteristic of the fluid dynamic model. Controller was designed and thereafter, simulation was performed to control the output signal with respect to the reference input in the fluid dynamic model using the proposed proportional control valve. Hybrid controller combined with an proportional controller and feed-forward controller was fabricated after applying a disturbance observer to the control plant. Comparison of the simulations between the conventional proportional controller and the proposed hybrid simulator indicated that even though the former showed good control performance.

• 한국컴퓨터정보학회논문지
• /
• 제22권9호
• /
• pp.149-154
• /
• 2017

The infusion of fluid and blood is necessary in the ward, operating room, recovery room, neonatal room, etc. for nutrition and blood supply to the patient, but air bubbles generated during infusion of fluid and blood circulate along the artery or vein. Serious illnesses occur and there is also a risk of death. In this paper, we propose a medical bubble detection system, a bubble detection system, a bubble detection alarm system, and a communication method in order to develop a safer fluid and blood injection system in the existing system, which is detected by a medical staff monitoring system or an ultrasonic bubble detection sensor In this study, infrared rays are transmitted to a tube through a tube for injecting fluid or blood into a patient, infrared rays transmitted by an infrared ray emitting section are received, and the amount of light is measured in real time. Based on the data, we study how to detect and analyze the presence of bubbles in fluid and blood.

• Nuclear Engineering and Technology
• /
• 제51권7호
• /
• pp.1842-1852
• /
• 2019

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steadystate and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

• Journal of Korean Neurosurgical Society
• /
• 제37권6호
• /
• pp.427-431
• /
• 2005

Objective: The purpose of this study is to evaluate the radiological charactersitics related to the formation of peritumoral edema in meningiomas. Methods: Fifty patients with meningioma were examined by magnetic resonance images and cerebral angiography. The predictive factors associated peritumoral edema, such as, tumor size, peritumoral rim (cerebrospinal fluid cleft), shape of tumor margin, signal intensity of tumor in T2WI, and pial blood supply were evaluated. Results: Tumor size, peritumoral rim and pial blood supply correlated with peritumoral edema on univariate analyses. But in multivariate analyses, pial blood supply was statistically significant as a factor for peritumoral edema in meningioma. Conclusion: In our results, pial blood supply is significant contributing factor for peritumoral edema in meningioma.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.17-24
• /
• 2001

To solve the problems of energy and environment conservation issued recently, mainly in mechanical engineering point of view, R&D's on the thermal, fluid and environmental engineering technology have been carried out by two R&D departments in the Korea Institute of Machinery & Materials (KIMM). Now there are 65 researchers in the two. The representative projects in the field of thermal and fluid engineering are development of an inactive gas generator and development of a cryogenic cooler for electronic sensors. Pyrolysis and melting of wastes, gas treatment using nonthermal plasma, and desalination are important technology to be developed in environmental R&D areas. To reduce the emission from the existing diesel engines for buses, an LPG direct injection type of bus engine is being developed supported by LPG supply companies. These several R&D projects which have been carried out in KIMM are introduced briefly.

• Tribology and Lubricants
• /
• 제12권3호
• /
• pp.85-91
• /
• 1996

An analysis for turbulent hybrid beatings with fluid inertia and swirl injection effect was derived for studying static characteristics of swirl-controlled hybrid journal. The swirl-controlled hybrid journal beating is considered to have more freedom in stability control in high speed rotating machinery. Current analysis is compared with experimental results with 3-recess hydrostatic journal bearing. The analysis revealed that the fluid momentum exchange at orifice discharge could produce pressure rise inside the recess region which can control the shear flow induced by journal rotation. The analysis also shows that the swirl-controlled hybrid journal beating has a capability of controlling load carrying capacity and stability by manipulating supply pressure and injection angle.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
• /
• pp.191-196
• /
• 2001

In the systems with largely pipe head loss, variable speed pumps are generally used because substantial energy saving can be expected from such systems by controlling pump speed and also they offer simpler maintenance and operational ease even in conditions where abrupt changes In flow rate and head can occur. The invertor or the fluid coupling system are mainly adopted to control the rotating speed. In this paper, operating conditions at Migum pressing pump station(5 stage), where the fluid coupling system was the first installed for KOWACO, are investigated and analysed so that information thus gained can be usefully employed in the efficient operation of variable speed pump in new installations of in-line booster pumping station.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2000년도 추계학술대회 논문집
• /
• pp.178-183
• /
• 2000

Electrorheological(ER) effect on the dispersive system of polarizable fine powder/dielectric oil has been investigated. The electrical and rheological properties of zeolite and starch based ER fluid were reported. The ER fluids were constructed by mixing zeolite and starch power with two different dielectric oils. Yield stress of the fluids were measured on the couette cell type rheometer as a function of electric fields, particle concetrations, and temperatures. The electric field is applied by high voltage DC power supply. The outer cup is connected to positive electrode(+) and the bob becomes ground(-). And the temperatures the viscosity(or shear stress) versus shear rates were measured. In this experiment shear rates were increased from 0 to $200s^{-1}$ in 2 minutes.

• 한국암석학회:학술대회논문집
• /
• 한국암석학회 2006년도 동계학술심포지엄
• /
• pp.43-60
• /
• 2006

The Yeongnam Massif, one of Precambrian basements in Korean Peninsula, is characterized by widespread occurrence of low-pressure/high-temperature (LP/HT) schists and gneisses accompanying extensive anatexis and granitic magmatism. Metapelitic mineral assemblages define three progressive metamorphic zones pertinent to low-pressure facies series: cordierite, sillimanite and garnet zones with increasing temperature. Metamorphic grade ranges from lower amphibolite to lower granulite facies and metamorphic conditions reach ca. 750-800 C and 4-6 kbar in migmatitic gneisses. Migmatitic gneisses are prominent in the sillimanite and garnet zones. Textural and petrogenetic relationshipsin leucosome suggest that migmatitic gneiss is the product of anatexis of metasedimentary rocks. The migmatite formation during the prograde metamorphism is governed initially by fluid-present melting and subsequently by biotite-dehydration melting. The large amount of leucosomes in the sillimaniteand garnet zones can be explained by the fluid-present molting possibly triggered by an external supply of aqueous fluid. Field and geochronologic relationships between leucogranites and migmatitic gneisses further suggest that leucogranite has providedfluid and heat required for widespread migmatization.

• 설비공학논문집
• /
• 제7권1호
• /
• pp.132-141
• /
• 1995

Characteristics of pressure-drop oscillations(PDO) in a boiling channel were studied numerically and compared with experimental data. Effects of initial and boundary conditions on PDO were investigated in terms of oscillation period and amplitude. The period and amplitude of PDO increased with increasing of the compressible volume in the surge tank and the heat input. PDO occurred within the specific range of the fluid temperature, at which oscillation period and amplitude diminished rapidly with the increase of the fluid temperature. The increase of the loss coefficient in fluid supply line resulted in slightly longer oscillation period and larger amplitude. Numerical results showed good agreement with the experimental data.