• Title/Summary/Keyword: Pressure shock

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Definition, Role and Method of Yinyang Pattern Differentiation (음양변증(陰陽辨證)의 정의와 기능 및 판별방법 연구)

  • Chi, Gyoo-yong;Park, Shin-hyung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.2
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    • pp.47-55
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    • 2021
  • In order to ensure the fact that eight principle pattern differentiation is used clinically as a basic guideline for Korean medicine practice, the definition, role and method of yin-yang pattern differentiation with its case report were explored at first. Yinyang Pattern Differentiation is a method of discriminating human tendencies or morbidity based on the yin and yang characteristics expressed in living bodies. And yin and yang are the two contrasting characteristics and aspects of the interaction when certain physical conditions that have a lasting effect on the human physiological metabolic function are correlated with the morbidity. Specific methods of yinyang pattern differentiation can be divided into several types of yin and yang indicators. First, time and space factors like day and night, hot and cold seasons, above and below, topographical districts. Second, colors and pulse and their/or relative clearness and muddiness, hardness and softness, moving and resting. Third, diagnose yin and yang patterns through distinguishing the true and false of a fever and cold in an emergency phase such as increase of brain pressure and shock state. Fourth, general characteristics of the propensity and constitution of a subject such as body type, speech, behavior, and physiological metabolism. And for clinical use, these were summarized again as a symptom indicators of physical signs and color, pulse, tongue and questionnaire indicators of propensity, body type, and space-time characteristics. Conclusively, it was confirmed that yinyang pattern differentiation has its own diagnostic significance which is distinct from exterior-interior, cold-heat and deficiency-excess pattern differentiation.

Blast Analysis of Single Degree of Freedom Plant Structures Considering Static Displacement (정적변위를 고려한 플랜트 구조물의 단자유도 폭발 해석)

  • Lee, Jae-Kyoon;Lee, Seung-Hoon;Kim, Han-Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.5
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    • pp.317-324
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    • 2022
  • In this paper, an analysis method that considers the initial static displacement of structural members using an equivalent single-degree-of-freedom system is presented. Newmark's dynamic analysis algorithm was improved to consider the effect of the initial static displacements of structural members. The effect of the initial static displacement on the maximum response according to the assumed duration of the blast load and natural period of the member was investigated. The effects of positive and negative static displacements on the maximum dynamic responses of structural members subjected to a positively applied blast load were also studied. Modified response charts for the shock-type and pressure-type waves are presented so that static displacements can easily be considered. Using a design example, we demonstrate the significance of the modified response chart that considers the static displacement. Based on the results of this study, the maximum response of a the structural member can be easily obtained whilst considering its initial static displacement. The modified response chart presented in this study can be used for the structural design of plants and military facilities.

A study on the Improvement of Electromyography of Agricultural Work Chairs for the Prevention of Musculoskeletal Disorders

  • June Hwan Kim;Eun Suk Lee;Won Sik Choi
    • International journal of advanced smart convergence
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    • v.12 no.2
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    • pp.76-83
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    • 2023
  • Squatting of agricultural work can cause musculoskeletal disorders due to excessive pressure and rotational force on the knee joint In order to improve the assistive chair used in squatting agricultural work so that it can be used in a narrow groove, it is intended to improve the musculoskeletal harm of squatting work by attaching a spring on the assistive chair. Therefore, in the presenty study, 3D drawing was done using ProEngineer (3D), and a mock-up was produced and tested. Using pro-Engineer, it was judged that it was rare for plastic to be broken by a spring, so the analysis was conducted with a focus on springs. It was found that the structure that can absorb the shock according to the rigidity of the tape spring and balance the body is that the power to withstand the load of the weight is distributed as a whole when five springs are used. Electromyography was measured using ME600 (Mega Electronics, Finland) Measuring equipment attached to the waist, thighs, calves, and shins. EMG values were measured and compared with the prototype in two ways, when the worker did not wear the product and when he wore an existing product on the market. As a result of the experiment when using the prototype, the maximum EMG value for each part is considered to be helpful in preventing musculoskeletal diseases as the amount of muscle used is reduced in the waist, thighs, calves, and shins.

Predictors of massive transfusion protocols activation in patients with trauma in Korea: a systematic review

  • Dongmin Seo;Inhae Heo;Juhong Park;Junsik Kwon;Hye-min Sohn;Kyoungwon Jung
    • Journal of Trauma and Injury
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    • v.37 no.2
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    • pp.97-105
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    • 2024
  • Purpose: Massive transfusion protocols (MTPs) implementation improves clinical outcomes of the patient's resuscitation with hemorrhagic trauma. Various predictive scoring system have been used and studied worldwide to improve clinical decision. However, such research has not yet been studied in Korea. This systematic review aimed to assess the predictors of MTPs activation in patients with trauma in Korea. Methods: The PubMed, Embase, Cochrane Library, Research Information Sharing Service databases, KoreaMed, and KMbase were searched from November 2022. All studies conducted in Korea that utilized predictors of MTPs activation in adult patients with trauma were included. Results: Ten articles were eligible for analysis, and the predictors were assessed. Clinical assessments such as systolic and diastolic blood pressure, shock index (SI), prehospital modified SI, modified early warning system (MEWS) and reverse SI multiplied by the Glasgow Coma Scale (rSIG) were used. Laboratory values such as lactate level, fibrinogen degradation product/fibrinogen ratio, and rotational thromboelastometry (ROTEM) were used. Imaging examinations such as pelvic bleeding score were used as predictors of MTPs activation. Conclusions: Our systematic review identified predictors of MTPs activation in patients with trauma in Korea; predictions were performed using tools that requires clinical assessments, laboratory values or imaging examinations only. Among them, ROTEM, rSIG, MEWS, SI, and lactate level showed good effects for predictions of MTPs activation. The application of predictors for MTP's activation should be individualized based on hospital resource and skill set, also should be performed as a clinical decision supporting tools.

Structural Support of Aluminum Honeycomb on Cast PBX (알루미늄 허니컴(HC) 구조재 적용 주조형 복합화약)

  • Seonghan Kim;Keundeuk Lee;Haneul Park;Mingu Han
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.2
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    • pp.222-229
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    • 2024
  • As the operating condition for the penetrating missile has been more advanced, the survivability of main charge has been strongly required when the warhead impacts the target. Lots of efforts to desensitize explosives such as the development of insensitive molecular explosives or optimizing plastic-bonded explosives(PBX) systems has been made to enhance the survivability of main charge. However, these efforts face their limits as the weapon system require higher performance. Herein, we suggest a new strategy to secure the survivability of main charge. We applied structurally supportable aluminum honeycomb(HC) structure to cast PBX. The aluminum HC structure reinforces the mechanical strength of cast PBX and helps it to withstand external pressure without the reaction like detonation. In this study, impact resistance character, shock sensitivity and internal blast performance of PBXs reinforced with HC structure were investigated according to the application of aluminum HC structure. The newly suggested aluminum HC structure applied to cast PBX was proved to be a promising manufacturing method available for high-tech weapon systems.

Manual Therapy for Plantar Fasciitis: A Review of Clinical Study (족저근막염의 수기요법에 대한 문헌 연구 보고)

  • In-hwa Park;Yun-Yeop Cha;Min-Jeong Kim;In Heo;Byung-Jun Kim
    • Journal of Korean Medicine Rehabilitation
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    • v.34 no.3
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    • pp.53-63
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    • 2024
  • Objectives This study aims to analyze the effectiveness of manual therapy for the treatment of plantar fasciitis by reviewing existing randomized controlled trials. Specifically, it seeks to identify various manual therapy techniques and evaluate their applicability in clinical settings. Methods The study reviewed literature from six databases (PubMed, the Cochrane Library, China National Knowledge Infrastructure, ScienceON, Research Information Sharing Service, Korean studies Information Service System) up to April 2024. Studies were selected based on criteria including randomized controlled trials involving manual therapy for plantar fasciitis. Results An analysis of ten studies involving 714 patients revealed the use of techniques such as joint mobilization, muscle relaxation, and pressure point techniques. Manual therapy was found to be more effective in reducing pain than both extracorporeal shock wave therapy and routine physical therapy alone. However, caution is needed in generalizing these results due to the limited number of studies analyzed. No significant adverse effects were reported. Conclusions Manual therapy demonstrates potential as an effective treatment for plantar fasciitis, offering benefits in pain management and functional recovery. However, further high-quality randomized controlled trials are necessary to strengthen the clinical evidence and establish standardized treatment protocols.

Acute and Chronic Effects of Ethanol on the Cardiovascular and Hormonal Responses to Hemorrhage in Conscious Normotensive and Spontaneously Hypertensive Rats

  • Park, Yoon-Yub;Lee, Joong-Hee;Park, Jae-Sik;Yang, Eun-Kyoung;Ahn, Dong-Kuk;Kim, Hyeong-Jin;Lee, Won-Jung
    • The Korean Journal of Physiology
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    • v.27 no.1
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    • pp.67-77
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    • 1993
  • Acute and chronic effects of ethanol (EOH) administration on the cardiovascular and hormonal responses to repeated hemorrhage were investigated in conscious normotensive Wistar rats and spontaneously hypertensive rats (SHR). The chronic EOH treated group received 5% EOH (vol/vol) ad libitum in the drinking water far the first week,10% for the last 2 weeks, and 20% for the last 5 weeks from the age of 6 weeks. The EOH free group received tap water. Chronic EOH and EOH free groups were randomly subdivided into acute EOH infusion and control groups. Under ether anesthesia, catheters were inserted into the femoral vein and both femoral arteries. After rats regained consciousness and their blood pressure was stabilized, responses to quick hemorrhage (5 ml/kg BW) were tested. In the acute EOH infusion group, hemorrhage was induced 20 min after EOH infusion (1.0 g/kg BW), Baroreceptor reflex sensitivity was assessed by the ratio of changes in hen.1 rate and mean arterial pressure (${\Delta}HR/{\Delta}MAP$) immediately after the hemorrhage. Chronic EOH administration elevated MAP in Wistar rats. During acute EOH infusion, MAP do- creased and HR increased in all groups. In comparison to EOH free control rats, acute or chronic EOH treated rats showed a greater reduction in MAP and a smaller elevation in heart rate in response to a hemorrhage. The degree of MAP reduction was significantly greater in SHR than in Wistar rats. Both the acute and chronic EOH administration attenuated the baroreceptor reflex and retarded MAP recovery, again the trend being much more prominent in SHR. The increase in plasma vasopressin and lenin concentrations after hemorrhage were intensified by the chronic EOH administration. SHR showed a greater vasopressin response but a smaller lenin response than Wistar rats. These results indicate that the EOH treated rats, particularly SHB, are prone to shock by a hemorrhage, which may be partly attributed to an impaired baroreceptor reflex function.

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A study on design and performance test of fire door with high endurance performance in submarine tunnel (고내구성능을 갖는 해저터널 방화문 설계방안 및 성능시험 연구)

  • Park, Sang-Heon;Hwang, Ju-Hwan;Choi, Young-Hwan;An, Sung-Joo;Yoo, Yong-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.331-346
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    • 2018
  • In the tunnel of domestic high - speed railway, the main fire - fighting facility, fire - extinguishing passageway, is installed. However, due to the high pressure of the high - speed train, frequent breakage and maintenance are caused by strong shock and long - term vibration. In order to solve these problems, it is necessary to improve the fire door, but in Korea, it is installed by submitting a certificate by simple KS F 2296 performance test. At present, it is developed as a simple test certification by producing a real scale fireproof door without the theoretical examination in advance, so that a high cost for improvement is occurring in Korea. Therefore, through this study, structural analysis study which can preliminary structure review was carried out in order to design the refuge connection passage fire door and to improve the performance improvement. In order to secure the reliability of the result value, the official authentication test (KS F 2296) were compared.

Condensation processes in transonic two-phase flows of saturated humid air using a small-disturbance model (미교란 모델을 이용한 포화 습공기 천음속 2상 유동에서의 응축현상)

  • Lee, Jang-Chang;Zvi Rusak
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.23-29
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    • 2003
  • Transonic two-phase flow of Saturated humid air, in which relative humidity is 100%, with various condensation processes around thin airfoils is investigated. The study uses an extended transonic small-disturbance(TSD) model of Rusak and Lee [11, 12] which includes effects of heat addition to the flow due to condensation. Two possible limit types of condensation processes are considered. In the nonequilibrium and homogeneous process, the condensate mass fraction is calculated according to classical nucleation and droplet growth rate models. In the equilibrium process, the condensate mass fraction is calculated by assuming an isentropic process. The flow and condensation equations are solved numerical1y by iterative computations. Results under same upstream conditions describe the flow structure, field of condensate, and pressure distribution on airfoil's surfaces. It is found that flow characteristics, such as position and strength of shock waves and airfoil’s pressure distribution, are different for the two condensation processes. Yet, in each case, heat addition as a result of condensation causes significant changes in flow behavior and affects the aerodynamic performance of airfoils.

Comparative study on dynamic properties of argillaceous siltstone and its grouting-reinforced body

  • Huang, Ming;Xu, Chao-Shui;Zhan, Jin-Wu;Wang, Jun-Bao
    • Geomechanics and Engineering
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    • v.13 no.2
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    • pp.333-352
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    • 2017
  • A comparison study is made between the dynamic properties of an argillaceous siltstone and its grouting-reinforced body. The purpose is to investigate how grout injection can help repair broken soft rocks. A slightly weathered argillaceous siltstone is selected, and part of the siltstone is mechanically crushed and cemented with Portland cement to simulate the grouting-reinforced body. Core specimens with the size of $50mm{\times}38mm$ are prepared from the original rock and the grouting-reinforced body. Impact tests on these samples are then carried out using a Split Hopkinson Pressure Bar (SHPB) apparatus. Failure patterns are analyzed and geotechnical parameters of the specimens are estimated. Based on the experimental results, for the grouting-reinforced body, its shock resistance is poorer than that of the original rock, and most cracks happen in the cementation boundaries between the cement mortar and the original rock particles. It was observed that the grouting-reinforced body ends up with more fragmented residues, most of them have larger fractal dimensions, and its dynamic strength is generally lower. The mass ratio of broken rocks to cement has a significant effect on its dynamic properties and there is an optimal ratio that the maximum dynamic peak strength can be achieved. The dynamic strain-softening behavior of the grouting-reinforced body is more significant compared with that of the original rock. Both the time dependent damage model and the modified overstress damage model are equally applicable to the original rock, but the former performs much better compared with the latter for the grouting-reinforced body. In addition, it was also shown that water content and impact velocity both have significant effect on dynamic properties of the original rock and its grouting-reinforced body. Higher water content leads to more small broken rock pieces, larger fractal dimensions, lower dynamic peak strength and smaller elastic modulus. However, the water content plays a minor role in fractal dimensions when the impact velocity is beyond a certain value. Higher impact loading rate leads to higher degree of fragmentation and larger fractal dimensions both in argillaceous siltstone and its grouting-reinforced body. These results provide a sound basis for the quantitative evaluation on how cement grouting can contribute to the repair of broken soft rocks.