• Title/Summary/Keyword: Pressure relief

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A numerical study on the pressure relief by a vertical shaft in a high speed railway tunnel (고속열차의 터널 진입시 수직갱의 압력저감효과에 대한 수치해석 연구)

  • Kim, Hyo-Geun;Seo, Sang-Yeon;Ha, Hee-Sang;Kwon, Hyeok-Bin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.6
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    • pp.559-570
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    • 2013
  • High speed railway can transport large quantity of people and commodities in a short time and has become one of the most desirable and environmentally friendly transportation. However, it is hard to have a complicated route for high speed railways, construction of tunnels is essential to pass through a mountain area. When a high speed train enters a tunnel, pressure wave is created in a tunnel and the wave causes micro pressure wave and discomfort to passengers. In order to alleviate pressure wave in a tunnel, constructing a vertical shaft is one of the most efficient ways. This study represents a numerical analysis module, which takes into account the effect of a vertical shaft in a tunnel. The module can be used in a numerical program (TTMA) specialized for aerodynamics in a tunnel, and it was validated by comparing numerical results with various measurements in Emmequerung tunnel and results from numerical analysis using Fluent.

The Effects of Estrogen Replacement Therapy on Blood Pressure, Heart Rate Variability, and Climacteric Symptoms in Postmenopausal Women (에스트로젠 호르몬 대치요법이 혈압, 심박동변이, 갱년기증상에 미치는 효과)

  • Lee, Hae-Kyung
    • Women's Health Nursing
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    • v.8 no.2
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    • pp.151-164
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    • 2002
  • PURPOSE: Estrogen replacement therapy is indicated for the relief of hot flushes and urogenital atrophy, the prevention of osteoporosis and the reduction in risk of cardiovascular disease. The present study assessed by blood pressure, heart rate variability, and climacteric symptoms in menopausal women before treatment and at 1 month during estrogen replacement therapy. METHODS: The study sample consisted of 16 healthy menopausal women (range 49 to 59 years, mean : 53.4 years) attending menopausal clinics for the complaint of climateric symptoms at S. hospital in Chunchoen. They were all non-smokers and no patient had symptoms or evidence of cardiovascular disease. They took estrogen replacement therapy (conjugated estrogen 0.625 mg with or without medroxy progesteron 2.5mg) for 1 month. Blood pressure, heart rate variability(heart period and vagal tone) through ECG, and climacteric symptom were measured in all subjects before treatment and at 1 month during treatment. Climacteric symptom questionnaire which was developed by Neugarten et al.(1963) was modified with 20 items of question(Cronbach's alpha = 88 -.89). The data was collected from Sept. 1. 2000 to July. 30. 2001. RESULTS: There was no significant difference in mean systolic and diastolic pressure between the baseline and at 1 month during treatment. The mean heart period and vagal tone were slightly increased, but difference of mean heart period and vagal tone were not statistically significant between the baseline and at 1 month during treatment. The score of climacteric symptoms decreased significantly from the baseline after treatment. CONCLUSIONS: Even though, this study did not show that estrogen replacement therapy led decrease of blood pressure and increase heart rate variability, climacteric symptoms reduced much in all subjects after taking drugs. These results suggest that there is need to repeat study with long term period.

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Characteristics of the Buttock Interface Pressure According to Wheelchair Propulsion Speed and Various Back Reclined Seating Position (휠체어 추진속도 및 등받이 경사각도에 따른 둔부 압력 변화 특성)

  • Kwon, Hyuk-Cheol;Kong, Jin-Yong
    • Physical Therapy Korea
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    • v.12 no.2
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    • pp.1-10
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    • 2005
  • Pressure ulcers are serious complications of tissue damage that can develop in patients with diminished pain sensation and diminished mobility. Pressure ulcers can result in irreversible tissue damage caused by ischemia resulting from external loading. There are many intrinsic and extrinsic contributors to the problem, including interface tissue pressure, shear, temperature, moisture, hygiene, nutrition, tissue tolerance, sensory and motor dysfunction, disease and infection, posture, and body support systems. The purposes of this study were to investigate the relationship between buttock interface pressure and seating position, wheelchair propulsion speed. Seated-interface pressure was measured using the Force Sensing Array pressure mapping system. Twenty subjects propelled wheelchair handrim on a motor-driven treadmill at different velocities (40, 60, 80 m/min) and seating position used recline ($100^{\circ}$, $110^{\circ}$, $120^{\circ}$) with a wheelchair simulator. Interface pressure consists of average (mean of the pressure sensor values) and maximum pressure (highest individual sensor value). The results of this study were as follows; No significant correlation in maximum/average pressure was found between a static position and a 40 m/min wheelchair propulsion (p>.05). However, a significant increase in maximum/average pressure were identified between conditions of a static position and 60 m/min, and 80 m/min wheelchair propulsion (p<.05). No significant correlation in maximum pressure were found between a $90^{\circ}$ recline (neutral position) and a $100^{\circ}$, $110^{\circ}$, or $120^{\circ}$ recline of the wheelchair back (p>.05). No significant difference in average pressure was found between conditions of a $90^{\circ}$ recline and both a $100^{\circ}$ and $110^{\circ}$ recline of wheelchair back. However, a significant reduction in average pressure was identified between conditions of a $90^{\circ}$ and $120^{\circ}$ recline of wheelchair back (p<.05). This study has shown some interesting results that reclining the seat by $120^{\circ}$ reduced average interface pressure, including the reduction or prevention in edema. And interface pressure was greater during dynamic wheelchair propulsion compared with static seating. Therefore, the optimal seating position and seating system ought to provide postural control and pressure relief. We need an education on optimal seating position and a suitable propulsion speeds for wheelchair users.

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Case Report of Pressure Injury in Intracerebral Hemorrhage Patients Improved by Combining Radix Astragali Pharmacoacupuncture Solution during Antibiotic Treatment (항생제 치료 중 드레싱과 황기 약침액 도포를 병행하여 호전된 뇌출혈 환자 욕창 1례)

  • Geun Young Kim;Dabin Lee;Seon Uk Jeon;Han-Gyul Lee;Ki-Ho Cho;Sang-Kwan Moon;Woo-Sang Jung;Seungwon Kwon
    • The Journal of Internal Korean Medicine
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    • v.44 no.2
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    • pp.167-177
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    • 2023
  • Background: Pressure injuries are localized areas of damage to the skin and/or underlying tissue, usually over a bony prominence due to pressure. Cerebrovascular disease increases the risk of pressure injuries due to the immobility caused by physical paralysis. The general approach to managing a patient with pressure injuries should include pain relief, the treatment of the infection, optimizing nutritional intake, proper positioning, and contamination prevention. Nonetheless, the duration of treatment for pressure injuries varies from person to person. Case report: An 80-year-old female intracerebral hemorrhage patient developed a pressure injury. To improve the injury faster, a Radix Astragali pharmacoacupuncture solution was applied to the pressure sore. The pressure injury's width, length, and depth was assessed using a ruler, and the exudate amount and tissue types were assessed. The treatment was performed for 35 days. The rate at which the size of the pressure sore lessened increased since the Radix Astragali pharmacoacupuncture solution was applied to the pressure sore. In addition, the tissue type of the pressure injury improved, and the exudates decreased. There was no significant difference in the Pressure Ulcer Scale for Healing Tool 3.0, since the Radix Astragali pharmacoacupuncture solution was applied to the pressure injury. Conclusion: This clinical case study suggests that the Radix Astragali pharmacoacupuncture solution might be effective in speeding up the healing of pressure injuries.

The Sensitivity Analysis for LRV Opening Pressure in CANDU (중수로 원전에서 액체방출밸브의 개방압력에 대한 민감도평가)

  • Kim, S.M.;Kho, D.W.;You, S.C.;Kim, J.H.
    • Journal of Energy Engineering
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    • v.24 no.2
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    • pp.40-44
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    • 2015
  • Sensitivity on the reactor safety was evaluated for the safety margin and time delay applied to the opening pressure of liquid relief valve(LRV) of the primary heat transport system(PHTS) in the pressurized heavy water reactor(PHWR) type nuclear power plant. Since the LRV is the pressure boundary for the PHTS in the safety analysis, the operating of LRV has a significant effect on the safety analysis results. Therefore it is required during the regulatory review of Wolsong Unit 1 safety analysis to find the safety effect of the application of safety margin and time delay to the LRV opening pressure for the safety analysis of PHTS pressurizing events.

The Effects of Music on Patients with Chronic Back Pain (만성요통 환자에게 미치는 음악의 적용 효과)

  • Lee, Jun-Woo
    • The Journal of Korean Physical Therapy
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    • v.19 no.4
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    • pp.53-64
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    • 2007
  • Purpose: We investigated the effects of music on pain, blood pressure, and pulse in patients with chronic back pain. We tried to find some change of satisfaction of treatment and a sense. Method: We recruited total 30 patients with chronic back pain, who had pain from lumbago for more than six months. Subjects received electrotherapy and electrotherapy with music one at a time during me test, and subjects received one in the morning and the other one in the afternoon. We compared the test results between the electrotherapy and electrotherapy with music. Visual Analogue Scale was used to check the effect on pain. Blood pressure and pulse were checked, too. The gathered informatio was analyzed by t-test, independent sample t-test, and chi-square test. Results: There was statistically not significant difference between electrotherapy and electrotherapy with the music in VAS(Visual Analogue Scale)(p>0.05). There were statistically some significant differences between two groups in systolic pressure, diastolic pressure, and the pulse(p<0.05). Subject group showed statistically higher scores of satisfaction(p<0.05). There was significant difference between two groups(p<0.05) in the tingling and vibration sense. Conclusion: we found that the lumbago patients who are treated by electrotherapy with the music did not have additional difference in relief of pain, but electrotherapy with music can get better effects on their blood pressure, the pulse, satisfaction, and tingling-vibration sense. This means that the patients receive their treatment comfortably with rest. Therefore, We consider that it is desirable to play music to lumbago patients to offer the better treatment service to the patients.

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Effect of Bergamot Essential Oil-Inhalation on Chronic Pain after Surgery for Lumbar Spinal Stenosis (버가못 에센셜 오일 향흡입이 요추관협착증 환자의 수술 후 만성통증에 미치는 효과)

  • Seol, Geun-Hee;Jung, Myung-Hee
    • Journal of Korean Biological Nursing Science
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    • v.13 no.2
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    • pp.156-163
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    • 2011
  • Purpose: The purpose of this study was to examine the effects of a bergamot essential oil-inhalation on chronic pain after surgery for lumbar spinal stenosis. Methods: Fifty-two subjects were randomly assigned to the experimental (bergamot essential oil-inhalation) and control (almond oil-inhalation) group. All patients understood the purpose of this study and a written informed consent for the study was obtained. Results: Bergamot essential oil-inhalation was conducted during twenty minutes. Visual analog scale, blood pressure, heart rate, and respiratory rate were measured before and after treatment in the two groups. The visual analog scale score, heart rate, and respiratory rate in bergamot essential oil-inhalation group were significantly lower than those in almond oil-inhalation group. However, there was no significant difference in systolic and diastolic blood pressure between the two groups. Conclusion: Therefore, bergamot essential oil-inhalation is effective in alleviating pain, heart rate, and respiratory rate. These results suggest that bergamot essential oil-inhalation can be a useful method for the relief of chronic pain during the treatment after spinal surgery.

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.

Two Cases of Spontaneous Intracranial Hypotension Treated with Epidural Blood Patch (자발성 두개내 저압환자의 경막외 혈액봉합술 치험 2예)

  • Cho, Soung-Kyung;Joo, Hyun-Chul;Park, Chan-Hong;Kim, Bong-Il;Lee, Sang-Hwa;Oh, Hee-Jong
    • The Korean Journal of Pain
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    • v.12 no.1
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    • pp.152-156
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    • 1999
  • Spontaneous intracranial hypotension (SIH) is a rare syndrome which causes postural headache associated with low cerebrospinal fluid (CSF) pressure, without preceding events such as lumbar puncture, back trauma, operative procedure or illness. The headche is usually accompanied by nausea, vomiting, tinnitus, neck stiffness, vertigo, photophobia and in rare cases diplopia, transient visual obscuration. Brain MRI may show subdural effusion, downward displacement of brain and diffuse and continuous meningeal enhancement when enhanced by gadolinium. Low opening pressure was shown through lumbar puncture. The value of protein and cell count of CSF may be slightly elevated. This syndrome usually resolves itself spontaneously or with strict bed rest. When the headache is persistent or incapacitating, more aggressive treatment may be necessary. We treated two cases of SIH in which epidural blood patch produced immediate and complete relief of the symptoms.

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Waterhammer For In-line Booster Pump (직결식 펌프의 수격현상)

  • Kim, S C.;Lee, K. B.;Kim, K. Y.
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.208-216
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    • 2004
  • The waterhammer occured when the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity. The field tests of the waterhammer were carried out for PanGyo booster pumping station. The PanGyo pumuing station was installed booster pump of 6 sets and in-line pump of 2 sets. The main surge suppression device was equipped with the pump control valve and the surge relief valve as auxiliary. However, the pump control valve had not early controlled in the planned closing mode, and the slamming occurred to the valve of which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. After the addition surge suppression device was equipped with air chamber. Further more in-line pump is needed surge suppression device that the pumping station acquired the safety and reliability for the pressure surge.

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