• Title/Summary/Keyword: Multiple Shock

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Experimental Study of Cushioning Pneumatic Cylinder with Meter In/Meter Out Control System (메타인 및 메타아웃 제어에 의한 공기압 실린더의 쿠션특성에 관한 실험적 연구)

  • 김동수;이상천
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.97-104
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    • 2000
  • Pneumatic cylinder is widely used for mechanical handling systems. Often, the impact occurs at the both ends points of pneumatic cylinder and generates destructive shock with in the structural operating members of the machine or equipment. To reduce the damage of system, therefore, shock absorbing devices are required. Cushioning of pneumatic cylinders at one or both ends of piston stroke is used to reduce the shock and vibration. The cylinder body have to withstand under high velocity and load. In this research, the pneumatic cushioning cylinder moving tests have been conducted for different load mass and supply pressure. The velocity of pneumatic cylinder actuation system with multiple orifice cushion sleeve which is set vertically controled with meter-in/out system. This study examines the dynamic characteristics of pneumatic cylinder with cushion devices. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion region characteristics was also revealed in the meter-in system.

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Effects of Self-Resilience and Social Support on Reality Shock among New Graduate Nurses (신규간호사의 자아탄력성과 사회적 지지가 현실충격에 미치는 영향)

  • Lee, Yeon Ju;Yeo, Jung Hee
    • Journal of East-West Nursing Research
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    • v.23 no.1
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    • pp.45-52
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    • 2017
  • Purpose: This study was to identify the effects of self-resilience and social support on reality shock among new graduate nurses. Methods: The data was collected using self-reported questionnaires from a convenience sample of 111 new graduate nurses. The data was analyzed by descriptive statistical, independent t-test, ANOVA, Scheffe test, Pearson correlation coefficient, and multiple regression via the SPSS Window 23.0 program. Results: Among general and work related characteristics, factors that have shown significant differences on reality shock were gender (t=-2.29, p=.024), work unit (t=3.31, p=.023) and whether they are working at unit they desired (t=-5.08, p<.001). Reality shock has shown a negative correlation with self-resilience (r=-.51, p<.001) and social support (r=-.41, p<.001). Factors that affected the reality shock on new graduate nurses were self-resilience (${\beta}=-.43$, p<.001), whether they are working at unit they desired (${\beta}=.35$, p<.001) and their currently work unit (${\beta}=-.17$, p=.028). These factors take into account of 38.0% of overall reality shock. Conclusion: The results suggest that self-resilience, desired unit and current work unit should be considered as factors when developing an intervention to alleviate the reality shock experienced by new graduate nurses.

Successive Interactions of a Shock Wave with Serially Arranged Vortices

  • Chang, Se-Myong;Chang, Keun-Shik
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.664-670
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    • 2004
  • Navier-Stokes computation based on a new simplified model is proposed to investigate the interactions of a moving shock wave with multiple vortices arranged in the serial manner. This model problem simulates shock-vortexlet interactions at the shear layer of a compressible vortex often observed in the experiment. Applying the Foppl's idea, we extended the Rankin's model generally used for the description of a single vortex to the multi-vortex version. The acoustic pulses accelerated and decelerated are successively generated and propagated from each shock-vortex interaction, which simply explains the genesis of eccentrically diverging acoustic waves appearing in the experimental photograph.

Plume Interference Effect on a Missile Body and Its Control (미사일 동체에서 발생하는 Plume 간섭 효과와 제어)

  • Lim, Chae-Min;Lee, Young-Ki;Kim, Heuy-Dong;Szwaba, Ryszard
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1730-1735
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    • 2003
  • The plume-induced shock wave is a complex phenomenon, consisting of plume-induced boundary layer separation, separated shear layer, multiple shock waves, and their interactions. The knowledge base of plume interference effect on powered missiles and flight vehicles is not yet adequate to get an overall insight of the flow physics. Computational studies are performed to better understand the flow physics of the plume-induced shock and separation particularly at high plume to exit pressure ratio. Test model configurations are a simplified missile model and two rounded and porous afterbodies to simulate moderately and highly underexpanded exhaust plumes at the transonic/supersonic speeds. The result shows that the rounded afterbody and porous wall attached at the missile base can alleviate the plume-induced shock wave phenomenon, and improve the control of the missile body.

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New Nurse's on Reality Shock and Organizational Commitment Convergence Study (신규간호사의 현실충격, 조직몰입 융복합연구)

  • Kim, Won Soon
    • Journal of Digital Convergence
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    • v.18 no.11
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    • pp.377-386
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    • 2020
  • This study aims to examine the effect of coaching leadership on reality shock and organizational commitment of new nurses in general hospitals. Data were analyzed through the SPSS/WIN 21.0 program using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and Standard Multiple Regression. Regression analysis proved relevance of the organizational commitment model (F=6.17, p<.001), and coaching leadership had 39.2% explanatory power on reality shock. The results of the study showed that coaching leadership lowers reality shock and boosts organizational commitment of new nurses. This study provides necessary background knowledge of human and material resource management to alleviate the reality shock and help vocational adaptation to reduce turnover rates of new nurses. Hence, with such results, this study aims to provide basic information on future coaching leadership research and coaching leader defense program developments.

POSTOPERATIVE TOXIC SHOCK SYNDROME: REPORT OF A CASE (Toxic Shock Syndrome의 증례보고)

  • Jang, Hyon-Seok;Kwon, Jong-Jin;Lim, Jae-Seok;Lee, Kab-Jae
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.21 no.1
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    • pp.69-73
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    • 1999
  • Toxic shock syndrome is an acute disease involving multiple organs. I described here a case of TSS associated with intranasal packing. Four major criteria, which are involvement of multiple organ systems, fever, hypotension or shock, and rash with subsequent desquamation should be fulfilled for the diagnosis. The exact pathogenesis is not well understood, however it is thought to be due to the effects of an enterotoxin produced by certain strains of staphylococcus aureus.

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Origin of the Multiple Type II Solar Radio Bursts Observed on December 31 2007

  • Cho, Kyung-Suk;Bong, Su-Chan;Kim, Yeon-Han;Kwon, Ryun-Young;Park, Geun-Seok;Moon, Yong-Jae;Park, Young-Deuk
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.37.1-37.1
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    • 2009
  • Solar type II radio burst is regarded as a signature of coronal shock. However its association with coronal mass ejections (CMEs)-driven shock and/or flare blast waves remains controversial. On December 31 2007, SOHO/LASCO and STEREO/COR observed a CME that occurred on the east limb of the Sun. Meanwhile, two type II bursts were observed sequently by KASI/E-Callisto and the Culgoora radio observatory during the CME apparence time. In this study, we estimate kinematics of the two coronal shocks from dynamic spectrum of the multiple type II bursts and compare with the kinematics of the CME derived from the space observations. An origin of the multiple type II bursts is inspected and discussed briefly.

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Effect of flow bleed on shock wave/boundary layer interaction (유동의 흡입이 충격파/경계층의 간섭현상에 미치는 영향)

  • Kim, Heuy-Dong;Matsus, Kazuyasu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1273-1283
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    • 1997
  • Experiments of shock wave/turbulent boundary layer interaction were conducted by using a supersonic wind tunnel. Nominal Mach number was varied in the range of 1.6 to 3.0 by means of different nozzles. The objective of the present study is to investigate the effects of boundary layer flow bleed on the interaction flow field in a straight tube. Two-dimensional slits were installed on the tube walls to bleed the turbulent boundary layer flows. The bleed flows were measured by an orifice. The ratio of the bleed mass flow to main mass flow was controlled within the range of 11 per cent. The wall pressures were measured by the flush mounted transducers and Schlieren optical observations were made for almost all of the experiments. The results show that the boundary layer flow bleed reduces the multiple shock waves to a strong normal shock wave. For the design Mach number of 1.6, it was found that the normal shock wave at the position of the silt was resulted from the main flow choking due to the suction of the boundary layer flow.

Effect of Nursing Work Environment and Social Support on Reality Shock Experienced by New Graduate Nurses (신규간호사의 간호근무환경과 사회적 지지가 현실충격에 미치는 영향)

  • Kim, Ji Hye;Noh, Yoon Goo
    • Korean Journal of Occupational Health Nursing
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    • v.33 no.2
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    • pp.55-63
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    • 2024
  • Purpose: The purpose of this study was to identify the effects of nursing work environment and social support on the reality shock of new graduate nurses in university hospitals. Methods: The subjects were 153 new graduate nurses with less than 12 months of clinical experience at two university hospitals in the G province, and data were collected from September 15 to October 7, 2020. Data were analyzed using the SPSS/WIN 26.0 program for frequency, average, t-test, ANOVA, Pearson correlation coefficient, multiple regression. Results: Factors influencing reality shock were nursing work environment (β=-.39, p<.001) and social support (β=-.25, p=.002), and gender (female) (β=.20, p=.001), and the explanatory power was 44.8% (F=9.99, p=.002). Conclusion: Our study shows that nursing work environment and social support play an important role in the reality shock of new graduate nurses. It is important to strengthen nursing work environment and social support to alleviate the reality shock of new graduate nurses. The findings of this study may serve as a basis for developing strategies for mitigating the reality shock of new graduate nurses.

A Study on the Fracture Mode Characteristics of Automotive Application Component Lead-free Solder Joints (자동차 전장부품 무연솔더 접합부의 파괴모드 특성에 관한 연구)

  • Jeon, Yu-Jae;Kim, Do-Seok;Shin, Young-Eui
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.6
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    • pp.90-96
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    • 2011
  • In this study, the characteristic of fractured portion and shape on solder joints were investigated according to the thermal shock test for Automotive Application Component using Sn-3.0Ag-0.5Cu solder, which has a outstanding property as Lead-free solder. The value of pull and shear strength was decreased in principle after 432 cycles thermal shock test. In addition, fracture mode was verified by using EDS and SEM to observe fractured shape on the solder joints before and after thermal shock. In before thermal shock test, the fracture mode revealed typically solder layer's fracture mode. In after thermal shock test, we identified multiple fracture mode of the ductile and brittle fracture. Even though same composition of solder was used to experimental for estimating. the fracture mode varied on the fracture portion's height and the directional angles of shear strength. In conclusion, we identified that mechanical strength was affected on the solder layer's fracture mode.