• Title/Summary/Keyword: stress reduction technique

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Acute Displaced Fracture of Lateral Acromion after Reverse Shoulder Arthroplasty: A Case Report and Surgical Technique

  • Cho, Chul-Hyun;Jung, Jae-Won;Lim, Young-Jae;Na, Sang-Soo;Kim, Du-Han
    • Clinics in Shoulder and Elbow
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    • v.22 no.2
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    • pp.106-109
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    • 2019
  • Acromial fractures are well-documented complications subsequent to reverse shoulder arthroplasty (RSA), and most appear as stress fractures with no history of single trauma. To date, no study has reported the occurrence of acute displaced acromial fracture due to sudden strong deltoid contraction during heavy work. Displacement of the fracture results in a challenging surgery since it is difficult to obtain adequate fixation in thin and osteoporotic bones. We report a rare case of acute displaced acromial fracture after successful RSA treatment, using a novel technique of open reduction and internal fixation, applying two 4.5 mm cannulated screws and lateral clavicle precontoured plate.

Arthroscopic Reduction of Subluxed Medial Meniscus using Suture Anchor for Restoration of Hoop Stress - Technical Note - (버팀테응력 회복을 위한 아탈구된 내측 반월상 연골의 Suture anchor를 이용한 정복술 - 술기 보고 -)

  • Kim, Jaw-Hwa;Lee, Yoon-Seok;Kim, Chul;Han, Seung-Chul
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.3
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    • pp.280-284
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    • 2009
  • Purpose: The authors introduce a new technique of arthroscopic reduction of subluxed medial meniscus using suture anchor for the restoration of hoop stress. Operative Technique: Anterolateral, anteromedial, and medial midpatellar arthroscopic portal are used. Arthroscope was inserted through anterolateral portal. Through the scope, we confirmed subluxation of medial meniscus. Transection of menisci including radial and root tear were excluded. We released the anterior horn of medial meniscus through anteromedial and burred the future insertion site of suture anchor. After inserting suture anchor through medial midpatellar portal, we used 90 degree suture hook and no.2 Nylon to retrieve the suture of inserted anchor. We tied the suture by sliding knot-tying method. Weight bearing was limited for 6 weeks postoperatively. Conclusion: Arthroscopic retightening of medial meniscus is less invasive, conserving and progressed method for subluxed meniscus.

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Photochemical assessment of maize (Zea mays L.) seedlings grown under water stress using photophenomics technique

  • Ham, Hyun Don;Kim, Tea Seong;Yoo, Sung Yung;Park, Ki Bae;Kim, Tae Wan
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.341-341
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    • 2017
  • Abiotic stress adversely affects crop growth worldwide. Drought of the major abiotic stresses have the most significant impact on all of the crop. The main objective of this study was to assess the effects of drought stress on photochemical performance and vitality of maize (Zea mays L.). The photochemical characteristics were analyzed in the context of period of drought stress during the maize growth. Drought experiment was carried out for four weeks, thereafter, the drought treated maize was re-watered. The polyphasic OJIP fluorescence transient was used to evaluate the behavior of photosystem II (PSII) and photosystem I (PSI) during the entire experiment period. In drought stress, the performance Index (PI) level was reached earlier when compared to the controls. For the screening of drought stress tolerance the drought factor index (DFI) of each variety was calculated as follow DFI= log(A) + 2log(B). All the fourteen cultivars show DFI ranged from -0.69 to 0.30, meaning less useful in selection of drought tolerant cultivars. PI and electron transport flux values of fourteen cultivars were to indicate reduction of photosynthetic performance during the early vegetative stage under drought stress. In conclusion, DFI and energy flux parameters can be used as photochemical and physiological index.

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A Study on Transferred Load Reduction on Paved Track Roadbed with Low Elastic Base Plate Pad (저탄성 베이스플레이트 패드 적용에 따른 포장궤도 노반에서의 전달하중 저감에 관한 연구)

  • Lee, Il-Wha;Kang, Yun-Suk;Lee, Hee-Up
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.399-405
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    • 2008
  • Development of the paved track is required as a low-maintenance of conventional line. The paved tracks are one of the types of the ballast reinforced tracks those are manufactured by adopting the prepacked concrete technique. The main elements of this tracks are large sleeper, low elastic pad, fastener, cement mortar, geotextile and recycled ballast. Low elastic pad is the most effective element of such tracks on the basis of stress-displacement characteristics, dynamic response and fatigue characteristics. The stiffness of the pad determine the stiffness of the track. Consequently, it is more important in case of concrete track structure such as paved track because application of low elastic pad seriously effect the durability and stability of the track. The main objective of this study is to confirm the reduction of train load, which transfer to roadbed through various pad effects. To achieve this task static, numerical analysis and real scale repeated loading test was performed while load reduction effect of low elastic pad was analyzed by using displacement, stress and strain ratio characteristics of the paved track.

Effect of Resource Mindfulness on Emotional State, Focusing on Anxiety and Stress Reduction (리소스 마인드풀니스에 관한 효과성 연구)

  • Seung Ho Lee;Do-Eun Lee;Yeoung-Su Lyu;Moon Joo Cheong;Hyung Won Kang
    • Journal of Oriental Neuropsychiatry
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    • v.35 no.2
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    • pp.177-189
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    • 2024
  • Objectives: This study aimed to evaluate the impact of Resource Mindfulness on participants' emotional state, focusing on anxiety and stress reduction and to explore the importance of psychological resources in this process. The effectiveness of Resource Mindfulness was investigated through both quantitative and qualitative analyses, examining its influence on subjective distress, mindfulness, core emotions, and identification of personal resources. Methods: This study involved 27 participants, including Korean medicine students, psychological counselors, clinical psychologists, and Korean medicine specialists, who attended a 2-night, 3-day M&L psychological support education program from July 2 to July 4, 2022. Participants were informed of the study's purpose and procedures. They provided written consent. Quantitative measures included Subjective Units of Disturbance Scale (SUDS), Five Facet Mindfulness Questionnaire (FFMQ), and Core Seven-Emotions Inventory Short Form (CSEI-s). Qualitative analysis was conducted using the "Drawing the Rooms of the Mind" technique. Pre- and post-program assessments were conducted to compare changes in subjective distress, mindfulness, and core emotions. Data were analyzed using paired t-tests and qualitative content analysis methods. Results: Significant reductions in subjective distress and improvements in mindfulness components were observed. Core emotions showed significant decreases in negative emotions. Qualitative analysis revealed increased tranquility, relief, and confidence, with resourceful places often being nature-related. Conclusions: Resource Mindfulness effectively reduced anxiety and stress and enhanced self-awareness and self-efficacy. It is useful for managing various mental health issues. Further research is needed to generalize these findings.

A Study on the Deformation of Cable Pipes via Induction Bending (고주파 벤딩을 통한 케이블 파이프의 변형에 관한 연구)

  • Joo, Yi-Hwan;Qin, Zhen;Moon, Seongmin;Lyu, Sung-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.4
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    • pp.79-84
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    • 2020
  • Induction bending via high-frequency heating is widely used for manufacturing pipe and section steel bends. It allows productivity improvement, unit cost reduction, delivery time compliance, and good mechanical properties. The recent increase in high-end vessels and offshore plants has raised the demand for high-frequency bending, which should improve the product quality and reduce the costs by simplifying the fabrication process; therefore, the characteristics and performance of this technique must be studied and proper design technology is required. During hot pipe bending via induction heating, the outward wall thickness of the pipe is thinned due to tensile stress and this thickness reduction cannot exceed 12.5%. This study focused on pipe bends with a bending curvature of 5D and their optimization design; in particular, the conditions that can both improve the productivity of the high-frequency bending process and keep the maximum thickness reduction below 12.5% were determined.

A Study Viscous Drag Reduction of Three Dimensional Double Model (3차원 2중 모형의 점성 항력 감소화 연구)

  • 김시영
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.30 no.3
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    • pp.209-219
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    • 1994
  • The practical application of riblet to three dimensional double model, for viscous drag reduction, was studied analytically by intergal solution to three dimensional turbulent boundary layers. The case of a V-groove riblet technique on the shear stress and boundary layer velocities were incooperated in the computation of the flow over a smooth slender ship hull. As the results the possible mechanism of turbulent drag reduction by riblets are then suggested based on detailed studies of near-wall turbulence characteristics. And a turbulent boundary layer calculation scheme based on a momentum integral method was modified for the computer program. An example of the calculation results is presented.

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An Optimum Design of Pipe Bending Process Using High Frequency Induction Heating and Dynamic Reverse Moment (고주파 유도가열 및 동적 반력 모멘트를 이용한 파이프 벤딩 공정의 최적설계)

  • Lee, H.W.;Jung, S.Y.;Woo, T.K.;Kim, C.
    • Transactions of Materials Processing
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    • v.19 no.2
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    • pp.79-87
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    • 2010
  • The Pipe bending process using high frequency local induction heating is an advanced technique to bend pipes with a small bending radius and a large diameter. Even though the pipe bending process is a quite widespread engineering practice, it depends heavily upon trial and error method by field engineers with several years of experience. So it is necessary to develop an integrated methodology for optimum design of the pipe bending process. During hot pipe bending using induction heating, outward wall thickness of a pipe is thinned due to tensile stress and the reduction of wall thickness is not allowed to exceed 12.5%. Taguchi method and dynamic reverse moment is proposed to maintain a reduction ratio of thickness within 12.5%, when D/t ratio is high. An application of the proposed approach was compared with those of the finite element analysis and has good in agreements.

A computationally efficient numerical integration scheme for non-linear plane-stress/strain FEM applications using one-point constitutive model evaluation

  • Hector R. Amezcua;Amado G. Ayala
    • Structural Engineering and Mechanics
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    • v.85 no.1
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    • pp.89-104
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    • 2023
  • This work presents a proposal for employing reduced numerical integration in the formulation of the 4-node quadrilateral solid finite element. The use of these low-order integration rules leads to numerical instabilities such as those producing the hourglass effect. The proposed procedure allows evaluating a given constitutive model only in one integration point, achieving an attractive computational cost reduction and, also, successfully controls the hourglass effect. A validation of the proposal is included and discussed throughout the paper. To show the efficiency of the proposal, several application examples of masonry structures are studied and discussed. To represent the non-linear mechanical behaviour of masonry a plastic-damage model is implemented within the application of this sub-integration scheme. Also, in order to have a full and computationally efficient strategy to determine the behaviour of masonry structures, involving its evolution to collapse, a homogenization technique with a macro-modeling approach is used. The methodology discussed throughout this paper demonstrates a substantial computational cost reduction and an improved approximation of the non-linear problem evidenced by a reduction of up to 85% of the computational time for some cases.

Analysis of actively-confined concrete columns using prestressed steel tubes

  • Nematzadeh, Mahdi;Haghinejad, Akbar
    • Computers and Concrete
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    • v.19 no.5
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    • pp.477-488
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    • 2017
  • In this paper, an innovative technique for finite element (FE) modeling of steel tube-confined concrete (STCC) columns with active confinement under axial compressive loading is presented. In this method, a new constitutive model for the stress-strain relationship of actively-confined concrete is proposed. In total, 14 series of experimental STCC stub columns having active confinement were modeled using the ABAQUS software. The results obtained from the 3D model including the compressive strength at the initial peak point and failure point, as well as the axial and lateral stress-strain curves were compared with the experimental results to verify the accuracy of the 3D model. It was found that there existed a good agreement between them. A parametric study was conducted to investigate the effect of the concrete compressive strength, steel tube wall thickness, and pre-stressing level on the behavior of STCC columns with active confinement. The results indicated that increasing the concrete core's compressive strength leads to an increase in the compressive strength of the active composite column as well as its earlier failure. Furthermore, a reduction in the tube external diameter-to-wall thickness ratio affects the axial stress-strain curve and the confining pressure, while increasing the pre-stressing level has a negligible effect on the two.