• Title/Summary/Keyword: Pressure shock

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A CLINICAL STUDY ON THE EMERGENCY PATIENTS WITH ACTIVE ORAL BLEEDING (구강내 과다출혈로 내원한 응급환자에 관한 임상적 연구)

  • Yoo, Jae-Ha;Kang, Sang-Hoon;Kim, Hyun-Sil;Kim, Jong-Bae
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.28 no.5
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    • pp.383-389
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    • 2002
  • This is a retrospective study on emergency patients with active oral bleeding. The study was based on a series of 135 patients treated as emergency patients at Wonju Christian Hospital, from Jan. 1, 1997, to Dec. 31, 2001. The postoperative bleeding was the most frequent cause of active oral bleeding in emergency room and bleeding from trauma and medically compromised (bleeding disorders) patients were next in order of frequency. In the injury of maxillofacial vessels, peak incidence was occurred in the inferior alveolar vessel (42.9%), followed by the submucosal vessel of lip & cheek, the superior alveolar vessel, and sublingual vessels. The most common disease of bleeding disorders was vascular wall alteration (infection, etc), followed by liver disease, thrombocytopenic purpura, anti-coagulation drugs in order. In the characteristics of dental diseases on bleeding disorders, periodontal disease and alveolar osteitis (osteomyelitis) were more common. The hemostasis was most obtained by use of wound suture, simple pressure dressing, drainage for infection control and primary interdental wiring of fracture. In the complication group, the infrequent incidence was showed in vomiting, hypovolemic shock, syncope, recurred bleeding & aspiration pneumonia. In the uncontrolled oral bleeding, the injured vessels were suspected as skull base & ethmoidal vessels. In this study, authors found that the close cooperation between the dentistry (Oral and maxillofacial surgery) and the medicine (emergency & internal medicine) was the most important for early proper control of active oral bleeding. And then post-operative wound closure, drainage for infection control and previous systemic evaluation of bleeding disorders were critical for the prevention of postoperative bleeding in the local dental clinic.

Crown removal and endodontic drainage as a last method in active gingival bleeding with liver cirrhosis and periodontitis: a case report (간경화증과 치주염으로 과도한 치은출혈을 보인 응급환자에서 최후 지혈방법으로 치관제거와 치근관 배농술: 증례보고)

  • Choi, Young-Su;Kang, Sang-Hoon;Kim, Moon-Key;Lee, Chun-Ui;Yoo, Jae-Ha
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.3
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    • pp.221-227
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    • 2010
  • The most common local cause of active gingival bleeding is the vessel engorgement and erosion by severe inflammation. Abnormal gingival bleeding is also associated with the systemic disturbances. Hemorrhagic disorders in which abnormal gingival bleeding is encountered include the following: vascular abnormalities (vitamin C deficiency or allergy), platelet disorders, hypoprothrombinemia (vitamin K deficiency resulting from liver disease), and other coagulation defects (hemophilia, leukemia). There are many conventional methods for gingival bleeding control, such as, direct pressure, electrocoagulation, direct suture, drainage, application of hemostatic agents and crushing and packing. If the active continuous gingival bleeding is not stopped in spite of the application of all conventional bleeding control methods, the life of patient is threatened owing to upper airway obstruction, syncope, vomiting and hypovolemic shock. Therefore, the rapid and correct hemostatic method is very important in the emergency dental care. This is a case report of active gingival bleeding care via dental crown removal and emergency primary endodontic drainage as a last method in liver cirrhosis patient with advanced periodontitis.

Experimental Study of the Multi-Row Disk Inlet

  • Maru, Yusuke;Kobayashi, Hiroaki;Kojima, Takoyuki;Sato, Tetsuya;Tanatsugu, Nobuhiro
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.634-643
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    • 2004
  • In this paper are presented a concept of a new supersonic air inlet, which is designated a Multi-Row Disk (MRD) inlet, aiming at performance improvement under off-design conditions, and results of wind tunnel tests examined performance characteristics of the MRD inlet. The MRD inlet is frequently called ‘a skeleton inlet’ because of its appearance. The performance of a conventional axisymmetric inlet with a solid center body (spike) deteriorates under off-design Mach number conditions. It is due to the fact that total pressure recovery (TPR) governed by the throat area of inlet and mass capture ratio (MCR) governed by an incidence position of an oblique shock from the spike tip into the cowl can not be controlled independently in such air inlet. The MRD inlet has the spike that is composed of a tip cone and several disks arranged downstream of it, based on the experimental fact that several deep cavities on a conical surface have little negative effect on the boundary layer growth. The overall spike length of the MRD inlet is adjustable to the given flight speed by changing space between disks so that a spillage flow can be controlled independently from controlling the throat area. It could be made clear from the result of wind tunnel tests that the MRD inlet improves TPR by 10% compared with a conventional inlet with a solid spike under off-design conditions.

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Assessment of the Counter-Flow Thrust Vector Control in a Three-Dimensional Rectangular Nozzle (3차원 직사각형 노즐에서 역유동 추력벡터 제어 평가)

  • Wu, Kexin;Kim, Tae Ho;Kochupulickal, James Jintu;Kim, Heuy Dong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.1
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    • pp.34-46
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    • 2020
  • Computational assessment of gas-dynamic characteristics is explored for a three-dimensional counter-flow thrust vector control system in a rectangular supersonic nozzle. This convergent-divergent nozzle is designed by Method of Characteristics and its design Mach number is specially set as 2.5. Performance variations of the counter-flow vector system are illustrated by varying the gap height of the secondary flow duct. Key parameters are quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, deflection angle, secondary mass flow ratio, and resultant thrust coefficient. Additionally, the streamline on the symmetry plane, three-dimensional iso-Mach number surface contour, and three-dimensional turbulent kinetic energy contour are presented to reveal overall flow-field characteristics in detail.

Studies on the Compositon of Protein and lycoprotein in Sarcopiasmic Reticulum of Skeletal Muscle (근소포체의 단백질 및 당단백질 조성에 관한 연구)

  • 박영철
    • The Korean Journal of Zoology
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    • v.33 no.2
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    • pp.191-199
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    • 1990
  • Sarcoplasmic reticulum subfractions were isolated from rabbit sarcoplasmic reticulum vesicles using ultracentrifugation in a continuous sucrose gradient (12.5% 50%) after French pressure treatment. And proteins in sarcoplasmic reticulum were detected by SDS-polyacrylamide gel electrophoresis and glycoproteins were identified through the reaction with 1251-concanavalin A.The electrophoresis showed that sarcoplasmic reticulum contained predominantly $Ca^2$+-AThase and calsequestrin along with high affinity calcium binding protein, intrinsic glycoprotein 160 Kd, 94 Kd, 80 Kd, 38 Kd, 34 Kd and 24 Kd proteins. Among these, the protein of about 80 Kd which has been known as one of heat shock proteins was especially enriched in the terminal cistemae of sarcoplasmic reticulum. Meanwhile, autoradiogram of 125 I-concanavalin A bound to the stained gels showed the distribution of glycoproteins which included 160 Kd glycoprotein, 94 Kd glycoprotein, calsequestrin and intrinsic glycoprotein Among these, the protein of about 160 Kd was especially enriched in longitudial sarcoplasmic reticulum and T-tubule, and the protein of about 94 Kd which has been known as one of glucose-regulated proteins was also enriched in T-tubule and sharply reduced in terminal cistemae.

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A Study on the meaning Hundertwasser's architecture in the modern Society (현대 사회에서 갖는 훈데르트바써(Hundertwasser) 건축의 의미)

  • 유연숙
    • Korean Institute of Interior Design Journal
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    • no.8
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    • pp.3-15
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    • 1996
  • Friedensreich Hundertwasser , born in Vienna 1928, is a painter, an architect and an environmentalist. His architecture is radically different from the traditional , straight -lined, functional architecture practised, for example, by the Bauhaus Masters. From the very beginning , he has tried by various means to show that radical change in thinking are necessary , possible and realized. Hundertwasser's goal in this architecture is to make and give human dwelling in harmony with nature. his architecture is characterized by avoidance of straight lines, " Window Right", irregular arrangement of windows, onion dom, a wealth of colours and such environmentally -friendly consideration as planting of roofs and realizing of "tree-tenants". hundertwasser sees houses as evolving creations which are to be shaped by their inhabitants. He hates Uniformity. The irregularity is always the guiding principle in his architecture. The Hundertwasser's architeucture express his fundamental belief that we may not simply rob nature of her resources, but that we must also return territory to nature which we habe stolen from her. Roofs, terraces and courtyards planted with vegetation and " tree-tenants" build bridges between man and nature. They influse the architecture with vitality and romanticism and are a statement of a quality rather than a standard of living. It is quite possible to value the architecture of Hundertwasser as an important inspiration, as a sort of turning point in the thoughts and actions of city planners. It's success could be healing shock for the international architectural community, which is hypnotized by technology and abused by the shortsighted interests of ren.tability . Under this pressure, today's architects trend to reduce people to a mere part of the " Dwelling machine", without acknowledging that in the long run such machines eat away at people's souls.uch machines eat away at people's souls.

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Analysis of the Interaction Between Hypersonic Free Stream and Side Jet Flow Using a DSMC Method (직접모사법을 이용한 극음속 대기 유동과 측면 제트의 상호 작용 해석)

  • Kim, Min-Gyu;Kwon, Oh-Joon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.3
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    • pp.1-9
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    • 2005
  • The interaction between hypersonic free stream and side jet flow at high altitudes is investigated by using the direct simulation Monte Carlo (DSMC) method. In order to alleviate the difficulty associated with the large density difference between the free stream and the side jet flow and to simulate the two flows simultaneously, a weighting factor technique is applied. For validation, the corner flow over a pair of plates perpendicularly attached is calculated with and without a side jet, and the results are compared with experiment. For a more realistic configuration, the flow past a blunted cone cylinder shape is solved. The leeward or windward jet is injected into the free stream and the effect on the aerodynamic force and moment is observed at various flow angles. The lambda shock effect and the wake structure are studied in terms of the surface pressure differential. A higher interaction between the free stream and the side jet flow is observed when the side jet is injected in the windward direction.

A Study of the Thrust Vectoring Control Using Secondary Co- and Counter-Streams (2차 순유동과 역유동을 이용한 추력벡터 제어법에 관한 연구)

  • Lim Chae-Min;Kim Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.109-112
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    • 2004
  • Of late, the thrust vectoring control, using fluidic co-flow and counter-flow concepts, has been received much attention since it not only improves the maneuverability of propulsive engine but also reduces an additional material load due to the trailing control wings, which in turn reduce the aerodynamic drag. However, the control effects are not understood well since the flow field involves very complicated non: physics such as shock wave/boundary layer interaction, separation and significant unsteadiness. Existing data are not enough to achieve the effectiveness and usefulness of the thrust vectoring control, and systematic work is required for the purpose of practical applications In the present study, computational study has been performed to investigate the effects of the thrust vector control using the fluidic co-and counter-flow concepts. The results obtained show that, for a given pressure ratio, the thrust deflection angle has a maximum value at a certain suction flow rate, which is at less than $5\%$ of the mass flow rate of the primary jet. With a longer collar, the same vector angle is achievable with smaller mass flow rate.

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Development of a New Munk-type Breaker Height Formula Using Machine Learning (머신러닝을 이용한 새로운 Munk-type 쇄파파고 예측식의 제안)

  • Choi, Byung-Jong;Nam, Hyung-Sik;Lee, Kwang-Ho
    • Journal of Navigation and Port Research
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    • v.45 no.3
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    • pp.165-172
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    • 2021
  • Breaking wave is one of the important design factors in the design of coastal and port structures as they are directly related to various physical phenomena occurring on the coast, such as onshore currents, sediment transport, shock wave pressure, and energy dissipation. Due to the inherent complexity of the breaking wave, many empirical formulas have been proposed to predict breaker indices such as wave breaking height and breaking depth using hydraulic models. However, the existing empirical equations for breaker indices mainly were proposed via statistical analysis of experimental data under the assumption of a specific equation. In this study, a new Munk-type empirical equation was proposed to predict the height of breaking waves based on a representative linear supervised machine learning technique with high predictive performance in various research fields related to regression or classification challenges. Although the newly proposed breaker height formula was a simple polynomial equation, its predictive performance was comparable to that of the currently available empirical formula.

Field test and research on shield cutting pile penetrating cement soil single pile composite foundation

  • Ma, Shi-ju;Li, Ming-yu;Guo, Yuan-cheng;Safaei, Babak
    • Geomechanics and Engineering
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    • v.23 no.6
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    • pp.513-521
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    • 2020
  • In this paper, due to the need for cutting cement-soil group pile composite foundation under the 7-story masonry structure of Zhenghe District and the shield tunnel of Zhengzhou Metro Line 5, a field test was conducted to directly cut cement-soil single pile composite foundation with diameter Ф=500 mm. Research results showed that the load transfer mechanism of composite foundation was not changed before and after shield tunnel cut the pile, and pile body and the soil between piles was still responsible for overburden load. The construction disturbance of shield cutting pile is a complicated mechanical process. The load carried by the original pile body was affected by the disturbance effect of pile cutting construction. Also, the fraction of the load carried by the original pile body was transferred to the soil between the piles and therefore, the bearing capacity of composite foundation was not decreased. Only the fractions of the load carried by pile and the soil between piles were distributed. On-site monitoring results showed that the settlement of pressure-bearing plates produced during shield cutting stage accounted for about 7% of total settlement. After the completion of pile cutting, the settlements of bearing plates generated by shield machine during residual pile composite foundation stage and shield machine tail were far away from residual pile composite foundation stage which accounted for about 15% and 74% of total settlement, respectively. In order to reduce the impact of shield cutting pile construction on the settlement of upper composite foundation, it was recommended to take measures such as optimization of shield construction parameters, radial grouting reinforcement and "clay shock" grouting within the disturbance range of shield cutting pile construction. Before pile cutting, the pile-soil stress ratio n of composite foundation was 2.437. After the shield cut pile is completed, the soil around the lining structure is gradually consolidated and reshaped, and residual pile composite foundation reaches a new state of force balance. This was because the condensation of grouting layer could increase the resistance of remaining pile end and friction resistance of the side of the pile.