• 제목/요약/키워드: additional pressure

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Slope Stability due to Additional Embankment (제방 추가성토에 따른 사면안정)

  • Lee, Seung-Hyun;Jang, In-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.3232-3236
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    • 2012
  • Consolidation and remedies for slope stability were considered for the slope with additional embankment. Transferred stresses due to additional embankment were assessed by the derived formula based on elasticity theory. Available remedies for slope stability with additional embankment including JSP method, stone column method and EPS method were studied. Caution needed for using JSP method is high pressure which can result in heaving of adjacent soils. Shortages of used case and noise of construction of stone column method are also considered for the safe remedy for slope stability.

Influence of Cooling Condition of Casted Strips on Magnetic Properties of Nd-Fe-B Sintered Magnets

  • Jung, Hwaebong;Kim, Sumin;Moon, Hongjae;Oh, Yoon S.;Lee, Young-Joo;Lee, Hyun-Sook;Lee, Wooyoung
    • Metals and materials international
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    • v.24 no.6
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    • pp.1422-1431
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    • 2018
  • We investigated the additional (secondary) cooling effect of casted strips on the magnetic properties of Nd-Fe-B sintered magnets. The Nd-Fe-B sintered magnets were fabricated with the casted strips prepared without and with additional cooling. Additional cooling was achieved by blowing Ar gas at various pressures (0.1, 0.3, and 0.6 MPa) on the free-side surface of the strips during the strip-casting process. The higher magnetic properties of $H_c$, $B_r$, and $(BH)_{max}$ of the final Nd-Fe-B sintered magnets were obtained for 0.1 MPa rather than for 0.0 MPa. The best microstructure of the columnar grains in the casted strips was produced with the aid of a lower pressure of gas on the free-side surface. It was found that the microstructure of the strips affects the distribution of grains grown in the sintered magnets. This report demonstrates that the improved magnetic performance of Nd-Fe-B sintered magnets was achieved via additional gas cooling.

A Study of the Correlation between Spinal Curvatures, Plantar Pressure and Foot Angles (척추의 만곡과 족저부 압력 분포 및 발각도의 상관성 연구 - 족부 진단기의 임상적 활용 가능성 검토를 위한 예비연구 -)

  • Eun, Young-Joon;Song, Yun-Kyung;Lim, Hyung-Ho
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.2 no.2
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    • pp.1-16
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    • 2007
  • Objectives : The purpose of this study was to identify spinal curvatures, plantar pressure and foot angles in a walking. Methods : 19 outpatients under 19 years old were included. Plantar pressure and foot angle in a walking were measured by using Gaitview AFA-50. Spinal curvatures were measured by using radiograph. Results : The cervical lordotic angle is significantly difference with left and right plantar pressure(p=0.027). The thoracic kyphotic angle is significantly difference with left and right plantar pressure(p=0.026). Cobb's angle is significantly difference with left and right plantar pressure(p=0.027). The other plantar pressure were no difference from spinal curvatures and foot angle in a walking. Conclusion : There were no correlation between plantar pressure, spinal curvatures and foot angle. We consider that needed more additional study.

Linking Clinical Events in Elderly to In-home Monitoring Sensor Data: A Brief Review and a Pilot Study on Predicting Pulse Pressure

  • Popescu, Mihail;Florea, Elena
    • Journal of Computing Science and Engineering
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    • v.2 no.2
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    • pp.180-199
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    • 2008
  • Technology has had a tremendous impact on our daily lives. Recently, technology and its impact on aging has become an expanding field of inquiry. A major reason for this interest is that the use of technology can help older people who experience deteriorating health to live independently. In this paper we give a brief review of the in-home monitoring technologies for the elderly. In the pilot study, we analyze the possibility of employing the data generated by a continuous, unobtrusive nursing home monitoring system for predicting elevated(abnormal)pulse pressure(PP) in elderly(PP=systolic blood pressure-diastolic blood pressure). Our sensor data capture external information(behavioral) about the resident that is subsequently reflected in the predicted PP. By continuously predicting the possibility of elevated pulse pressure we may alert the nursing staff when some predefined threshold is exceeded. This approach may provide additional blood pressure monitoring for the elderly persons susceptible to blood pressure variations during the time between two nursing visits. We conducted a retrospective pilot study on two residents of the TigerPlace aging in place facility with age over 70, that had blood pressure measured between 100 and 300 times during a period of two years. The pilot study suggested that abnormal pulse pressure can be reasonably well estimated (an area under ROC curve of about 0.75) using apartment bed and motion sensors.

Flow Analysis of Water Pump for Clean Disel Engine Application (클린 디젤엔진용 워터펌프 유동해석)

  • Lee, Dongju;Kim, Taeyoung;Chon, Mun Soo
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.61-65
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    • 2014
  • Pressure distribution around rotating impeller blades in centrifugal pump has been main issue for design of efficient and high performance automotive water pump. In addition, pressure losses of inlet water pipes should be considered to reduce additional pressure drop and design high performance engine cooling system. In this paper, pressure distribution inside water pump and pressure drop between inlet and outlet of water pump are investigated numerically to design plastic water pump for clean diesel engine application. And the inlet geometry of water pump was considered to analysis the effect of inlet water pipe geometry on pressure distribution around impeller blades and outlet pressure. The prediction results are compared with experimental data to validate and determine optimal operation condition without water pump cavitation. Major design parameters such as blade angle, volute geometry, system pressure, and coolant flow rate are considered to confirm applying possibility of plastic blades to the clean diesel engine.

Active Suspension using Disturbance Accommodating Sliding Mode Control (능동 현가 장치의 외란 적응 슬라이딩 모드 제어)

  • 김종래;김진호
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.3
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    • pp.275-280
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    • 1999
  • This paper presents a disturbance accommodating sliding mode control for a quarter-car active suspension using an electro-hydraulic actuator. The electro-hydraulic actuator model is nonlinear and uncertain. The hardware constrains on the actuator prevent high gain in a sliding mode control, which deteriorates the force tracking performance. DAC(Disturbance Accommodating Control) is combined with the sliding mode control to improve the tracking performance. DAC observer estimates the pressure due to the actuator uncertainty. The additional control is designed to compensate the estimated pressure. Simulation results show the improved tracking performance with the Proposed control methods.

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Estimation of Non- Invasive Blood Pressure Using Peripheral Plethysmograph (말초혈관 혈류 측정을 이용한 비관혈적 혈압 추정법에 대한 연구)

  • Jeong In-cheol;Shin Tae-min;Yoon Hyung-Ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.8
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    • pp.504-509
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    • 2005
  • This paper presents a new method for obtaining the noninvasive and unrestrained blood pressure readings noninvasively and unrestrainedly using based on reflected wave arrival time(RAT) in the volume of pulse. Since this new method employs only volume pulse, is more rapider and simpler than the method using pulse transit time(PTT) because it only employs the volume of pulse. Blood pressure, PTT and RAT were acquired from 15 healthy subjects. Each subjects were performed forty trials of each measurement. As a result of those trials, the mean error between oscillometric and RAT measurements for systolic blood pressure was $4.55\pm5.64mmHg$. This result showed quite equal with the mean error between oscillometric and PPT measurf:ments, $4.22\pm5.30mmHg$, However, it was not obtained a satisfactory result in the relativity of oscillometric to both RAT and PPT measurements for diastolic blood pressure because of personal difference. To conclude, the method of systolic blood pressure estimation noninvasively and unrestrainedly using by RAT may be used as the method by PTT. Nevertheless, additional studies would be necessary for the RAT/PTT estimation of diastolic blood Pressure measurement.

Consideration of Pressure-Rise and Water Hammer for Pipe System in Relation to Start-Up and Sudden Stop of the Pump (펌프 기동 및 정지에 따른 배관 압력상승과 수격작용 영향 고찰)

  • Heo, Min Woong;Min, Ji Ho
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.13 no.1
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    • pp.69-74
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    • 2017
  • In the fire protection system or fire fighting water supply system, the jockey pump is generally installed for the prevention of the pressure decrease of pipes, the frequent driving of the fire pump and protection the pipes from the water hammer. In this paper, the pressure-rise in fire fighting water distribution pipes in condition of pipe pressurization by the surge tank at the start-up and the sudden-stop of the fire pump without additional installation of jockey pump is considered by using simple formula calculations and the evaluation of water hammer occurrence in condition of pipe pressurization by the surge tank is included. As a result, the pressure-rise of pipes is less than the pipe design pressure at the condition of pump's start-up and sudden stop, and the possibility of water hammer occurrence is remarkably low due to pressurization of the pipes by the surge tank.

Influence of hot-pressing pressure on the densification of short-carbon-fiber-reinforced, randomly oriented carbon/carbon composite

  • Raunija, Thakur Sudesh Kumar;Sharma, Sharad Chandra
    • Carbon letters
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    • v.16 no.1
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    • pp.25-33
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    • 2015
  • The prime objective of this research was to study the influence of hot-pressing pressure and matrix-to-reinforcement ratio on the densification of short-carbon-fiber-reinforced, randomly oriented carbon/carbon-composite. Secondary objectives included determination of the physical and mechanical properties of the resulting composite. The 'hybrid carbon-fiber-reinforced mesophase-pitch-derived carbon-matrix' composite was fabricated by hot pressing. During hot pressing, pressure was varied from 5 to 20 MPa, and reinforcement wt% from 30 to 70. Densification of all the compacts was carried at low impregnation pressure with phenolic resin. The effect of the impregnation cycles was determined using measurements of microstructure and density. The results showed that effective densification strongly depended on the hot-pressing pressure and reinforcement wt%. Furthermore, results showed that compacts processed at lower hot-pressing pressure, and at higher reinforcement wt%, gained density gradually during three densification cycles and showed the symptoms of further gains with additional densification cycles. In contrast, samples that were hot-pressed at moderate pressure and at moderate reinforcement wt%, achieved maximum density within three densification cycles. Furthermore, examination of microstructure revealed the formation of cracks in samples processed at lower pressure and with low reinforcement wt%.

Porosity Prediction of the Coating Layer Based on Process Conditions of HVOF Thermal Spray Coating (HVOF 용사 코팅 공정 조건에 따른 코팅층의 기공도 예측)

  • Jeon, Junhyub;Seo, Namhyuk;Lee, Jong Jae;Son, Seung Bae;Lee, Seok-Jae
    • Journal of Powder Materials
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    • v.28 no.6
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    • pp.478-482
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    • 2021
  • The effect of the process conditions of high-velocity oxygen fuel (HVOF) thermal spray coating on the porosity of the coating layer is investigated. HVOF coating layers are formed by depositing amorphous FeMoCrBC powder. Oxygen pressure varies from 126 to 146 psi and kerosene pressure from 110 to 130 psi. The Microstructural analysis confirms its porosity. Data analysis is performed using experimental data. The oxygen pressure-kerosene pressure ratio is found to be a key contributor to the porosity. An empirical model is proposed using linear regression analysis. The proposed model is then validated using additional test data. We confirm that the oxygen pressure-kerosene pressure ratio exponentially increases porosity. We present a porosity prediction model relationship for the oxygen pressure-kerosene pressure ratio.