• Title/Summary/Keyword: back stress

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The Vietnam War and the Reception of Ecocide Consciousness (베트남전쟁과 에코사이드 의식의 수용)

  • Kim, Ilgu
    • English & American cultural studies
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    • v.18 no.4
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    • pp.1-31
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    • 2018
  • It is needless to say that America's indiscriminate artillery and chemical attacks have worsened the conditions of Vietnam's tropical rain forests, causing war-torn combat troops and civilians to suffer more from the participation and aftermath of the Vietnam war. Around two decades after the Vietnam War, American and Vietnamese writers dealing with the destruction of the human and nature of the Vietnam War and the following traumatic experience commonly report the horrors of inhumane warfare, but some differences among them appear in the reception of the ecocide consciousness. For American writers who had been involuntarily involved or who had stayed in the back area as interpreters and counter-intelligence force, the Vietnam War was often a kind of exotic "addicted adventure" which their American hometown could not provide. But apart from overcoming postwar post-traumatic stress by writing of healing which was shared with American war writers, Vietnamese writers have been able to overcome the scars of war as the communal memorial, which Jonathan Shay emphasized as the necessary comforting ritual by community members showing the sign of honor and care. On the other hand, American war writers were on the side of "separate peace," as Jeong stressed, and the Vietnam War to them was more racist like the case of "body count." Nevertheless, it is fortunate that the hideous experience of war could turn them all into the creativity pool, just as the 5,000 square mile of bomb creators have been used as the postwar fish ponds.

A Study on Structural Design and Analysis of Small Engine Test Equipment for Use in Aircraft (항공기 소형 엔진 시험 장치의 구조 설계 및 해석 연구)

  • Back, Kyeongmi;Park, Hyunbum
    • Journal of Aerospace System Engineering
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    • v.12 no.1
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    • pp.42-46
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    • 2018
  • The subject of this study dealt with the structural safety analysis regarding the measured thrust test equipment as noted on a small engine. In this work, the structural design and analysis of steel and aluminum alloy structure for a small engine test of equipment were performed. Firstly, the structural design requirements of the engine test equipment were identified and investigated. After the structural design was reviewed, next the structural analysis of the engine test equipment was performed by the utilization of the finite element analysis method. The study was performed to determine that the stress and displacement analysis was appropriately managed regarding the applied load condition. As a result, it was determined that through the structural analysis, this study has confirmed that the designed engine test equipment is approved for safety, and meets its design purpose at this time.

Influences of hands-only cardiopulmonary resuscitation on lumbar muscle tone, stiffness, and fatigue in emergency medical technicians (가슴압박소생술이 구조자의 허리근육의 근긴장도, 경직, 피로에 미치는 영향)

  • Wang, Joong-San;Shin, Sang-Yol
    • The Korean Journal of Emergency Medical Services
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    • v.24 no.3
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    • pp.79-87
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    • 2020
  • Purpose: This study sought to determine how the act of performing cardiopulmonary resuscitation (CPR) affects the rescuer's muscle tone, stiffness, and fatigue in the lumbar region. Methods: The research subjects were 30 healthy men in their twenties in possession of a Basic Life Support (BLS) provider certificate. In this study, the CPR rescuer's muscle tone and stiffness in the upper and lower lumbar regions were measured in the resting position, starting position, and position after 10 min. Their level of fatigue was measured before and after performing CPR. Results: Muscle tone and stiffness in the upper and lower lumbar regions of the research subjects significantly increased throughout the CPR process and lasted up to 10 min after the process (p<.001). The subjects' fatigue also significantly increased post-CPR (p<.001). Conclusion: This study suggests that performing CPR creates muscular and physiological stress, fatigue, and ultimately, lower back pain.

A Case Report of Golf-Swing-Induced T2~T3 Clay-Shoveler's Fractures (골프 초보자에서 나타난 흉추 2~3번 극돌기의 견열 골절)

  • Seo, Jae Sam;Park, Young Sook;Chang, Hyun Jung;Park, Jin Gee;Cho, Eun Sol;Ku, Kyo Hoon
    • Clinical Pain
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    • v.19 no.2
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    • pp.138-141
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    • 2020
  • Clay-shoveler's fractures are rare stress-type avulsion fractures of the spinous processes especially in sports. There have been two case reports that discussed clay-shoveler's fractures in golf. A 36-year-old beginner golfer presented with a pain in the back after practicing golf swing. No fractures were detected using cervical radiography; however, computed tomography (CT) and magnetic resonance imaging (MRI) revealed T2~T3 spinous process fractures. The patient was treated conservatively and his pain subsided. The mechanism of injury is speculated to that of clay-shoveler's fractures. Therefore, if a golfer suffers persistent pain in the cervicothoracic region, clay-shoveler's fracture is one possibility to consider.

Reliability Evaluation of Resilient Safety Culture Using Fault Tree Analysis

  • Garg, Arun;Tonmoy, Fahim;Mohamed, Sherif
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.303-312
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    • 2020
  • Safety culture is a collection of the beliefs, perceptions and values that employees share in relation to risks within an organisation. On the other hand, a resilient safety culture (RSC) means a culture with readiness of the organisation to respond effectively under stress, bounce back from shocks and continuously learn from them. RSC helps organisations to protect their interest which can be attributed to behavioural, psychological and managerial capabilities of the organization. Quantification of the degree of resilience in an organisation's safety culture can provide insights about the strong and weak links of the organisation's overall health and safety situation by identifying potential causes of system or sub-system failure. One of the major challenges of quantification of RSC is that the attributes that determine RSC need to be measured through constructs and indicators which are complex and often interrelated. In this paper, we address this challenge by applying a fault tree analysis (FTA) technique which can help analyse complex and interrelated constructs and indicators. The fault tree model of RSC is used to evaluate resilience levels of two organisations with remote and urban locations in order to demonstrate the failure path of the weak links in the RSC model.

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Buckling behavior of cold-formed steel lipped channel beam-column members under monotonic and cyclic loadings

  • Yilmaz Yilmaz;Serhat Demir;Ferhan Ozturk
    • Structural Engineering and Mechanics
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    • v.90 no.5
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    • pp.435-446
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    • 2024
  • The use of cold-formed steel members is increasing day by day, especially in regions where earthquake effects are intensively experienced. Among cold-formed steel members (CFS), "channel" members are used more than other crosssectional members, especially in buildings or industrial structures. In recent years, several studies have been carried out on the axial load and flexural performance of these members under monotonic loading. In this study, CFS beam-column members were cyclically and monotonically loaded under combined axial load and biaxial bending moments, and their buckling behavior, load bearing capacity, stiffness, ductility, and energy absorption capacity were determined. For this purpose, monotonic and cyclic loading experiments were carried out on 30 CFS channel members at 15 different eccentricities. Then, material properties were determined by axial monotonic tensile and very low cycle fatigue tests for use in numerical studies. From the experimental results, the buckling modes, bearing capacities, ductility, stiffness, and energy absorption capacities of the members were obtained. The characteristics of the members were compared according to the stress state of the lips. According to the data obtained from the displacement transducer placed on the lips and on the back of the web, information about the buckling mode and curvature of the members was obtained. Finally, monotonic, and cyclic loading results were compared to determine the differences in the buckling behavior of the members.

Critical face pressure and backfill pressure of shield TBM considering surface settlements of saturated clayey ground (쉴드 TBM 굴진에 따른 포화 점성토 지반의 침하거동을 고려한 한계 굴진면압과 한계 뒤채움압)

  • Kim, Kiseok;Oh, Ju-Young;Lee, Hyobum;Choi, Hangseok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.433-452
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    • 2018
  • The shield tunneling method can minimize surface settlements by preventing the deformation of tunnel face and tunnel intrados due to tunnel excavation. For this purpose, it is very important to control the operating conditions of shield TBM. The face pressure and backfill pressure for tail void grouting should be the most important and immediate measure not only to restrain surface settlement, but also to influence the effective stress and pore water pressure around the circumstance of tunnel during excavation. The reaction of the ground to the application of face pressure and backfill pressure relies on the stiffness and permeability of ground. Especially, the reaction of saturated clayey ground formations, which shows the time-dependent deformation, is different from the permeable ground. Hence, in this paper it was investigated how the TBM operating conditions, ground stiffness, and permeability impact on the surface settlement of saturated clayey ground. For this purpose, a series of parametric studies were carried out by means of the stress-pore water pressure coupled FE analysis. The results show that the settlement of soft clayey ground is divided into the immediate settlement and consolidation settlement. Especially, the consolidation settlement depends on the ground stiffness and permeability. In addition, the existence of critical face pressure and backfill pressure was identified. The face pressure and backfill pressure above the critical value may cause an unexpected increase in the ground settlement.

A study on excavator front support parts to minimize springback defects (굴삭기 Front Support 부품 뒤틀림 결함 최소화 방안 도출)

  • Jeon, Yong-Jun;Heo, Young-Moo;Lee, Ha-Sung;Kim, Dong-Earn
    • Design & Manufacturing
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    • v.12 no.2
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    • pp.40-45
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    • 2018
  • Recently, in construction equipment machinery production, development has focused on environmentally-friendly functions to improve existing production capacity. For excavators as well, emphasis has been placed on response to environmental regulations, miniaturization, and noise reduction, while technology is being developed considering cost reduction and safety.Accordingly, the front support, an inner reinforcement part of the excavator, as well as high-strength steel plates to improve safety and reduce weight, are being applied.However, in the case of high-strength materials, Springback occurs in the final formed part due to high residual stress during product forming. Derivation of a forming or product shaping process to reduce springback is needed. Accordingly, regarding the front support, an inner reinforcement part of the excavator, this study derived a method to improve springback and secure shape stiffness through analysis of the springback occurrence rate and springback causes through a forming analysis.As for the results of analyzing the springback occurrence rate of existing products through forming analysis, springback of -22.6 mm < z < 27.35 mm occurred on the z-axis, and it was confirmed that springback occurred due to the stiffness reinforcing bead of the upper and middle parts of the product.To control product residual stress and springback, we confirmed a tendency of springback reduction through local pre-cutting and stiffness reinforcement bead relocation.In the local pre-cutting model, springback was slightly reduced by 5.3% compared with the existing model, an insignificant reduction effect. In the stiffness reinforcement bead relocation model, when an X-shaped stiffness reinforcement bead was added to each corner portion of the product, springback was reduced by at least 80%.The X-shaped bead addition model was selected as the springback reduction model, and the level of stiffness compared to the existing model was confirmed through a structural analysis.The X-shaped bead additional model showed a stress springback of 90% and springback reduction of 7.4% compared with the existing model, indicating that springback and stiffness will be reinforced.

Effects of Nicarbazin and Hot Temperature on Water Balance, Acid-Base Balance, and Body Temperature in Adult Roosters (고온하의 수탉 성계에계 Nicarbazin의 급여가 수분 출납, 혈액의 산-염기 평형 및 체온에 미치는 영향)

  • 이봉덕;이수기
    • Korean Journal of Poultry Science
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    • v.20 no.3
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    • pp.151-159
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    • 1993
  • An experiment was conducted to study the effects of nicarbazin supplementation (125 ppm) on the water balance, blood acid-base balance, and rectal temperature of 16 SCWL adult roosters in normal($21^{\circ}C$) and hot(35~$36^{\circ}C$) temperatures. There were 4 d of preliminary period, followed by 2 d of sampling and data collection period for each temperature treatment. The amounts of DM intake and excretion were not affected by heat stress but by rucarbazln supplementation. The DM metabolizability of diets, however, was decreased by nicarbazin. The amounts of water intake and evaporative water loss were increased in heat stressed birds. Nicarbazin increased further the amounts of water intake and evaporative water loss in hot temperature. Nicarbazin also decreased the blood p$CO_2$ and increased blood pH of heat stressed birds. The rectal temperature of the bird was increased in hot temperature, and the nicarbazin supplementation worsened this effect. Results indicate that heat stress raises the body temperature of the chicken. In order to suppress the rise of body temperature, the birds enhance the evaporative water loss through panting. The nicarbazin supplementation to heat stressed birds, however, increases the body temperature to such an extent that panting alone may not be able to return the body temperature back to normal.

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The Comparison of Image Quality and Quantitative Indices by Wide Beam Reconstruction Method and Filtered Back Projection Method in Tl-201 Myocardial Perfusion SPECT (Tl-201 심근관류 SPECT 검사에서 광대역 재구성(Wide Beam Reconstruction: WBR) 방법과 여과 후 역투영법에 따른 영상의 질 및 정량적 지표 값 비교)

  • Yoon, Soon-Sang;Nam, Ki-Pyo;Shim, Dong-Oh;Kim, Dong-Seok
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.122-127
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    • 2010
  • Purpose: The Xpress3.$cardiac^{TM}$ which is a kind of wide beam reconstruction (WBR) method developed by UltraSPECT (Haifa, Israel) enables the acquisition of at quarter time while maintaining image quality. The purpose of this study is to investigate the usefulness of WBR method for decreasing scan times and to compare to it with filtered back projection (FBP), which is the method routinely used. Materials and Methods: Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on an equality with counts from patient's body. The Tl-201 concentrations in the compartments were 74 kBq (2 ${\mu}Ci$)/cc in myocardium, 11.1 kBq (0.3 ${\mu}Ci$)/cc in soft tissue, and 2.59 kBq (0.07 ${\mu}Ci$)/cc in lung. The non-gated Tl-201 myocardial perfusion SPECT data were acquired with the phantom. The former study was scanned for 50 seconds per frame with FBP method, and the latter study was acquired for 13 seconds per frame with WBR method. Using the Xeleris ver. 2.0551, full width at half maximum (FWHM) and average image contrast were compared. In clinical studies, we analyzed the 30 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center from January to April 2010. The patients were imaged at full time (50 second per frame) with FBP algorithm and again quarter-time (13 second per frame) with the WBR algorithm. Using the 4D MSPECT (4DM), Quantitative Perfusion SPECT (QPS), and Quantitative Gated SPECT (QGS) software, the summed stress score (SSS), summed rest score (SRS), summed difference score, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were analyzed for their correlations and statistical comparison by paired t-test. Results: As a result of the phantom study, the WBR method improved FWHM more than about 30% compared with FBP method (WBR data 5.47 mm, FBP data 7.07 mm). And the WBR method's average image contrast was also higher than FBP method's. However, in result of quantitative indices, SSS, SDS, SRS, EDV, ESV, EF, there were statistically significant differences from WBR and FBP(p<0.01). In the correlation of SSS, SDS, SRS, there were significant differences for WBR and FBP (0.18, 0.34, 0.08). But EDV, ESV, EF showed good correlation with WBR and FBP (0.88, 0.89, 0.71). Conclusion: From phantom study results, we confirmed that the WBR method reduces an acquisition time while improving an image quality compared with FBP method. However, we should consider significant differences in quantitative indices. And it needs to take an evaluation test to apply clinical study to find a cause of differences out between phantom and clinical results.

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