• Title/Summary/Keyword: Repaired effect

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Service life of concrete culverts repaired with biological sulfate-resisting mortars

  • Hyun-Sub, Yoon;Keun-Hyeok, Yang;Nguyen, Van Tuan;Seung-Jun, Kwon
    • Computers and Concrete
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    • v.30 no.6
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    • pp.409-419
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    • 2022
  • The purpose of this study is to examine the effectiveness of biological repairing mortars on restoring the structural performance of a sewage culvert deteriorated by sulfate attack. The biological mortars were developed for protecting concrete structures exposed to sulfate attack based on the block membrane action of the bacterial glycocalyx. The diffusion coefficient of sulfate ions in the biological mortars was determined from the natural diffusion cell tests. The effect of sulfate-attack-induced concrete deterioration on the structural performance of culverts was examined by using the moment-curvature relationship predicted based on the nonlinear section lamina approach considering the sulfuric-acid-induced degradation of the structure. Typical analytical assessments showed that biological mortars were quite effective in increasing the sulfate-resistant service life of sewage culverts.

Critical Criteria Based on Facility Condition Index for Supporting Priority Decision-making in Educational Facilities

  • Shin, Seung Woo;Yi, June Seong
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.687-688
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    • 2015
  • The objective of identifying the cause of inconsistency in determining priority of educational facility maintenance, any related factors were thoroughly identified and tested, to see if it has any effect on decision-making process in resource allocation for educational facilities. On the assumption that 'the more there are to be repaired/maintained and deferred, the higher the relevant cost will be, this will lead to a significant social loss. Accordingly, this study established a framework of determining resource allocation priority based on deferred maintenance and its related expenses. For doing so, it was required to determine relative ranking in terms of resource allocation within a pre-assigned school district, in consideration of the criticality of each deferred maintenance attribute/variable.

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Optimization of scarf patch stacking sequences using the design of experiments method

  • Salma Aminallah;Sidi Mohamed Fekih;Abdelrahmen Sahli
    • Advances in aircraft and spacecraft science
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    • v.10 no.4
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    • pp.335-346
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    • 2023
  • In this study, The Von Mises stresses in composite plate loaded in tension and repaired by a boron/epoxy scarf patch were analyzed using the finite element method. The performance of the repairs depends on several parameters: the dimensions and the intrinsic properties of the patch and the adhesive which are dependent on each other. Therefore, the method of experiment designs is used to determine the interaction effect of different parameters (patch folds), their optimum and the most influential parameter. The optimum of stacking sequences allows reducing stresses significantly, and thus permits designers to improve the quality of repairs.

Unilateral Platysma Muscle Rupture as an Effect of Using a Hard Wooden Block for Facial Massage

  • Kyu Hwa Jung;Eun-Jung Yang;Won Lee
    • Archives of Plastic Surgery
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    • v.51 no.1
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    • pp.27-29
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    • 2024
  • Facial massages are frequently performed to achieve a feeling of freshness, rejuvenation, skin tightening, and delayed onset of wrinkles. However, vigorous massages can induce unexpected symptoms. Here, we present a case of a woman who complained of an asymmetric facial appearance and a mass-like lesion following a long-term facial massage intervention. A facelift incision was performed. Platysma muscle rupture was observed intraoperatively, which was then repaired. To our knowledge, this is the first report of a vigorous facial massage-induced ipsilateral platysma rupture.

A Study on Design of Wireless Networks using Mesh Networks (메쉬 네트워크를 활용한 무선 네트워크망 설계에 관한 연구)

  • Choi, Yong-Seok;Rho, Jung-Kyu
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.45-50
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    • 2014
  • In this paper, broadband wireless smart city network coverage was implemented targeting a city (Wonju) using the wireless mesh network. Through this, we could provide wireless network that can easily add network and be repaired easily and have high economic effect. In order to implement broadband wireless smart city network coverage, wireless mesh network has been designed through pre-survey of the region and appropriate selecting of equipment. In addition, the designed network is examined, evaluated and compared with existing network though simulation. The aim of this paper is to prove high cost saving effect of wireless mesh network and its superior performance and to suggest future oriented integrated network of Green IT though research.

Restoration of pre-damaged RC bridge columns using basalt FRP composites

  • Fahmy, Mohamed F.M.;Wu, Zhishen
    • Earthquakes and Structures
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    • v.14 no.5
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    • pp.379-388
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    • 2018
  • This study aims to identify the effect of both longitudinal reinforcement details and damage level on making a decision of repairing pre-damaged bridge columns using basalt fiber reinforced polymer (BFRP) jackets. Two RC bridge columns with improper details of the longitudinal and/or transverse reinforcement were tested under the effect of a constant axial load and increasing lateral cyclic loading. Test results showed that the lap-splice column exhibited an inferior performance where it showed rapid degradation of strength before achieving the theoretical strength and its deformation capacity was limited; however, quick restoration is possible through a suitable rehabilitation technique. On the other hand, expensive repair or even complete replacement could be the decision for the column with the confinement failure mode. After that, a rehabilitation technique using external BFRP jacket was adopted. Performance-based design details guaranteeing the enhancement in the inelastic performance of both damaged columns were addressed and defined. Test results of the repaired columns confirmed that both reparability and the required repairing time of damage structures are dependent on the reinforcement details at the plastic hinge zone. Furthermore, lap-splice of longitudinal reinforcement could be applied as a key design-tool controlling reparability and restorability of RC structures after massive actions.

A Study of the Mechanical Properties of Patch-Bonded and Riveted Repairs on Cracked Al 6061-T6 alloy Structures

  • Yoon, Young-Ki;Kim, Guk-Gi;Yoon, Hi-Seak
    • International Journal of Precision Engineering and Manufacturing
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    • v.1 no.2
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    • pp.55-60
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    • 2000
  • A comparison of Riveted and bonded repairs, bearing and net tension failures, and Al 6061-T6 plates is presented. The results are then compared with previous papers about bonded repairs on different patch materials and shapes. Aluminum alloys, including Al 6061-T6, have a face-centered-cubic crystal structure. Under normal circumstances, these types of crystal structures do not exhibit cleavage fractures even at very low temperatures. In aluminum-base structures, the cracked plate structures are frequently repaired using mechanical fasteners-either rivets of bolts- even though patch-bonding techniques are applied to repair and reinforce the structure. Static test results indicate that the riveted repairs are affected by the position of the rivers. When using the same size of patch, the bonded repair technique is stronger; the rate of elongation is also increased. Form FEM analysis, it is revealed the origin of patch debonding in patch-bonded structures is the edge of the patch along to the tensile strength.

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Effect of InJinORyungSan on the nephrotoxicity in rat (인진오령산이 흰쥐의 신독성(腎毒性)에 미치는 영향(影響))

  • Kim, Ho-Hyun;Shin, Heung-Mook;Kim, Gil-Whon
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.133-144
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    • 1996
  • This study investigated the effect of InJinORyungSan on the nephrotoxicity in rat treated with cyclosporin A. Control group were injected with cyclosporin A alone. whereas test group were injected with cyclosporin A and InJinORyungSan extract. In the control group, blood urea nitrogen(BUN), serum creatinine(S-Cr) and renal lipid peroxidation(LPO) level were significantly increased, but renal superoxide dismutase(SOD) activity was significantly decreased. In the kidney of control group, the destruction of distal convoluted tubules(DCT) and proximal convoluted tubules(PCT) were observed in renal cortex, lymphocytes and fibroblast were appeared in the portion of DCT destruction. However, in the test group, BUN, S-Cr and renal LPO level were significantly decreased as compared with control group, on the other hand, renal SOD activity was significantly increased. In the kidney of test group, the destruction of DCT and PCT were repaired as compared with control group. These results demonstrated that InJinORyungSan. can be attributed to recovery from nephrotoxicity, We consider that activated SOD by InJinORyungSan suppress renal LPO or production of free radicals induced by cyclosporin A.

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Effect of stacking sequence of the bonded composite patch on repair performance

  • Beloufa, Hadja Imane;Ouinas, Djamel;Tarfaoui, Mostapha;Benderdouche, Noureddine
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.295-313
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    • 2016
  • In this study, the three-dimensional finite element method is used to determine the stress intensity factor in Mode I and Mixed mode of a centered crack in an aluminum specimen repaired by a composite patch using contour integral. Various mesh densities were used to achieve convergence of the results. The effect of adhesive joint thickness, patch thickness, patch-specimen interface and layer sequence on the SIF was highlighted. The results obtained show that the patch-specimen contact surface is the best indicator of the deceleration of crack propagation, and hence of SIF reduction. Thus, the reduction in rigidity of the patch especially at adhesive layer-patch interface, allows the lowering of shear and normal stresses in the adhesive joint. The choice of the orientation of the adhesive layer-patch contact is important in the evolution of the shear and peel stresses. The patch will be more beneficial and effective while using the cross-layer on the contact surface.

Effect of Similar Metal Weld & Preemptive Weld Overlay On Residual Stress of Repair Weldment In Surge Nozzle (고리 원전 밀림관 노즐의 동종용접과 예방용접 Overlay가 보수용접 잔류응력에 미치는 영향)

  • Oh, Chang-Young;Song, Tae-Kwang;Shim, Kwang-Bo;Kim, Ji-Soo;Kim, Yun-Jae;Lee, Kyung-Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.6
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    • pp.557-564
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    • 2009
  • Welding residual stress is occurred after welding process. Tensile residual stress is one factor of PWSCC. Repair welding usually happened during the manufacturing welding process. Repair welds cause strong tensile residual stress. In PWR, Repair weldments made by Alloy 82/182 is susceptible to PWSCC caused by tensile stress, material and environment. Therefore, mitigation of welding residual stress in weldments is important for reliable operating. PWOL is one of the methods for mitigation and verified for over twenty years. In this paper, residual stress distribution of repaired weldments and the effect of PWOL on mitigation is examined for surge nozzle.