• Title/Summary/Keyword: Tie-down

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Structural integrity of KJRR-F fresh nuclear fuel under vehicle-induced vibration for normal transport condition

  • Jeong, Gil-Eon;Yang, Yun-Young;Bang, Kyoung-Sik
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1355-1362
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    • 2022
  • Nuclear fuel, including its fresh state, must be handled safely due to its critical and hazardous nature. Under normal transport conditions, several interactions take place among different components, such as transport cask used for loading the nuclear fuel and tie-down structure to attach with the vehicle. To ensure structural integrity of the nuclear fuel, vibrations and impacts transmitted from the vehicle must be sufficiently reduced. Therefore, in this study, we conducted two transportation tests from Daejeon to Kijang in Korea to verify the vehicle-induced vibrational characteristics of the KJRR-F fresh nuclear fuel when transported under normal transport conditions. The speed and location of the vehicle were obtained via GPS, and the accelerations between the vehicle and the KJRR-F fresh nuclear fuel were measured. Additionally, using the acceleration results, a structural analysis was conducted to confirm the structural integrity of the nuclear fuel under the most severe conditions during normal transport.

Modal Characteristics of Control Element Assembly Shroud for Korean Standard Nuclear Power Plant(I) : Pre-Test Analysis (한국표준형 원자력발전소 제어봉집합체 보호구조물의 모우드 특성)

  • Jhung, Myung-Jo;Choi, Suhn;Song, Heuy-Gap;Park, Keun-Bae
    • Computational Structural Engineering
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    • v.5 no.3
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    • pp.105-112
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    • 1992
  • The design of reactor internals requires the accurate vibration characteristics of each component for subsequent dynamic structural response analysis. For Korean standard nuclear power plant some modifications on the Control Element Assembly shroud from the reference design have been made. Since the shroud is complex in geometry having an array of vertical round tubes and webs in a square grid pattern, and being tied down by preloaded tie rods into position, it is planned to perform a vibration measurement program consisting of both experimental and analytical modal studies upon that component. To determine the proper test conditions, the pre-test analysis has been performed using the general purpose structural analysis program ANSYS. Also the effects of the number of master degrees of freedom, holes in the web and tie-rod preload on the natural frequencies are examined prior to the pre-test analysis. After decision of appropriate finite element model, frequency analysis and harmonic analysis are performed and ideas for the test conditions such as the number of measurement points, their locations, measurement frequency range and the excitation force level are determined.

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A Study on Small-sized Index Structure and Fast Retrieval Method Using The RCB trio (RCB트라이를 이용한 빠른 검색과 소용량 색인 구조에 관한 연구)

  • Jung, Kyu-Cheol
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.4
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    • pp.11-19
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    • 2007
  • This paper proposes RCB(Reduced Compact Binary) tie to correct faults of both CB(Compact Binary) tie and HCB(Hierarchical Compact Binary) trie. First, in the case of CB trie, a compact structure was tried for the first time, but as the amount of data was increasing, that of inputted data gained and much difficulty was experienced in insertion due to the dummy nods used in balancing trees. On the other hand, if the HCB trie realized hierarchically, given certain depth to prevent the map from increasing on the right, reached the depth, the method for making new trees and connecting to them was used. Eventually, fast progress could be made in the inputting and searching speed, but this had a disadvantage of the storage space becoming bigger because of the use of dummy nods like CB trie and of many tree links. In the case of RCB trie in this thesis, the tree-map could be reduced by about 35% by completely cutting down dummy nods and the whole size by half, compared with the HCB trie.

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Construction and Design Related Issues in Road Widening for Concrete Pavement (콘크리트포장 확장접속부의 시공 및 설계상의 문제점 분석)

  • Yang, Sung-Chul
    • International Journal of Highway Engineering
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    • v.8 no.4 s.30
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    • pp.25-36
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    • 2006
  • Through field surveys and evaluation on several widened concrete pavements, issues on construction and design related problems are broken down into three categories to be discussed; poor smoothness, influence of traffic vibration on concrete curing, and poor connection to the existing pavement. There are many places where about 100mm only of the marginal strip is removed and where defects such as widening and faulting are observed. Also cracks arise again from the patched areas due to stress concentration near the joint. Roughness on the widened concrete pavement was evaluated and there are some stations where the smoothness limit is over passed. For design consideration, shortage of the required force in the tie-bar is expected in case of road widening specially from 3 lanes to 4 lanes. Finally the average pull-out force of specimens made from the current practice was about 57% of the required force. New connecting methods were suggested in this study.

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Structural Safety Assessment of Tie-down for Securing Helicopter (헬리콥터 고정용 안전장치 구조 안전성 평가)

  • Myung Su Yi;Kwang-Chul Seo;Joo Shin Park
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.4
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    • pp.372-379
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    • 2023
  • International oil prices are expected to increase from $85 a barrel this year to up to $100 a barrel in the second half of the year; this is likely to increase orders for offshore plants in the global market. One main characteristic of offshore plants is that a large helideck is located on the top side, and aluminum alloys are used as the basic material of the structure for weight reduction and corrosion resistance. Shipowners are increasing the size of helicopters to quickly evacuate lives in the event of an emergency, and the safety use load of devices that can stably secure helicopters to the deck is also required to increase. Owing to the nature of the aluminum material, the structural strength caused by welding is greatly reduced; therefore, the fixing device must be designed by embedding it in the deck and fixing it with bolts. In this study, a model applying aluminum alloy 6082-T6 was developed to develop a helicopter fastening device that can be used for large helidecks (diameter = 28 m). The developed item was verified through nonlinear structural strength calculation to satisfy the load used for the actual fastening condition. The load condition with a 45° showed a lower ultimate strength than the 90° case owing to local plastic collapse. The nonlinear structural collapse behavior showed a result similar to that of the experimental test. The main contents derived from this study are considered to be reference materials when evaluating the structural strength of similar aluminum equipment.

Lynching and Ethics in Faulkner's Fiction (포크너 소설에 나타난 린칭과 윤리의 문제)

  • Hwang, Eunjoo
    • Journal of English Language & Literature
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    • v.54 no.2
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    • pp.281-299
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    • 2008
  • The main purpose of this essay is to suggest that Faulkner's "pro"-lynching letter published in Commercial-Appeal in 1931 does not contradict his antilynching works such as "Dry September," Light in August, Go Down, Moses, and Intruder in the Dust. In the letter, Faulkner writes, "they [lynching mobs] have a way of being right." The remark has been interpreted as the expression of Faulkner's sympathetic attitude toward lynching mobs; however, it can be also seen as Faulkner's observation and criticism of the southern white people's structures of feeling in his time that stubbornly justified lynching as a way to do justice to black people who did "not" deserve to be a legal subject. This essay argues that Faulkner understood that the legislation of anti-lynching law alone could not save black people from the violence of lynching as far as white people believed that black people were not their equals and that lynching was a right means to fulfill social justice. Faulkner's fictions such as Light in August and Go Down, Moses provide moments in which white male characters feel as if they were social others, and their experiences work as an ethical urge for them to stand up for social others. This essay illuminates how Faulkner depicts the process of white male characters' identity formation as a violent break from his strong tie with black friends, how they reverse the process to blur the border again through the experiences of becoming-other, and how the experience of becoming-other has a potentiality to play the role of an ethical agency in stopping the custom of lynching in the South.

Effects of Down-regulation of HDAC6 Expression on Proliferation, Cell Cycling and Migration of Esophageal Squamous Cell Carcinoma Cells and Related Molecular Mechanisms

  • Li, Ning;Tie, Xiao-Jing;Liu, Pei-Jie;Zhang, Yan;Ren, Hong-Zheng;Gao, Xin;Xu, Zhi-Qiao
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.685-689
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    • 2013
  • Objective: To study the effects of down-regulation of HDAC6 expression on proliferation, cell cycling and migration of esophageal squamous cell carcinoma (ESCC) cells and related molecular mechanisms. Methods: ESCC cell line EC9706 cells were randomly divided into untreated (with no transfection), control siRNA (transfected with control siRNA) and HDAC6 siRNA (transfected with HDAC6 small interfering RNA) groups. Effects of HDAC6 siRNA interference on expression of HDAC6 mRNA and protein in EC9706 cells were investigated by semi-quantitative RT-PCR, Western blotting and immunocytochemistry methods. Effects of down-regulation of HDAC6 expression on cell proliferation, cell cycle, and cell migration were studied using a CCK-8 kit, flow cytometry and Boyden chambers, respectively. Changes of mRNA and protein expression levels of cell cycle related factor (p21) and cell migration related factor (E-cadherin) were investigated by semi-quantitative RT-PCR and Western blotting methods. Results: After transfection of HDAC6 siRNA, the expression of HDAC6 mRNA and protein in EC9706 cells was significantly downregulated. In the HDAC6 siRNA group, cell proliferation was markedly inhibited, the percentage of cells in G0/G1 phase evidently increased and the percentage of cells in S phase decreased, and the number of migrating cells significantly and obviously decreased. The mRNA and protein expression levels of p21 and E-cadherin in the HDAC6 siRNA group were significantly higher than those in the untreated group and the control siRNA group, respectively. Conclusions: HDAC6 siRNA can effectively downregulate the expression of HDAC6 mRNA and protein in EC9706 cells. Down-regulation of HDAC6 expression can obviously inhibit cell proliferation, arrest cell cycling in the G0/G1 phase and reduce cell migration. The latter two functions may be closely related with the elevation of mRNA and protein expression of p21 and E-cadherin.

Numerical Analysis of Smart Anchors in Soft Clay by (수치해석을 이용한 연약지반에 시공된 스마트 앵커의 거동 분석)

  • Kim, Nak-Kyung;Kim, Sung-Kyu;Kang, Byung-Chul;Kim, Jeong-Ryeol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.964-968
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    • 2010
  • Ground anchor, commonly referred to as tiebacks or tie-down, is essentially steel elements secured in the ground by cement grout. They are used to provide either lateral or vertical support for various engineered structures, and are effective in all types of soil and rock. However, ground anchor can not be used in soft clay because anchor resistance would not be guaranteed. In this paper, conceptual introduction of the Smart Anchor is presented. The Smart Anchor is a kind of friction type anchor, the load is diffused and applied to the various parts of the distributed bond length, having less impact on the grout strength, and being able to secure necessary anchoring force in relatively soft grounds. This study shows a numerical study of predicting the load transfer of The Smart Anchor in soft clay. A beam-column analysis was performed by a elastic-plastic P-y curves in soft clay.

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Investigation of design values computation of wood shear walls constructed with structural foam sheathing

  • Shadravan, Shideh;Ramseyer, Chris C.
    • Advances in Computational Design
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    • v.4 no.3
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    • pp.223-238
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    • 2019
  • This study investigated the ultimate lateral load capacity of shear walls constructed with several types of structural foam sheathing. Sixteen tests were conducted and the results were compared to the published design values commutated by the manufactures for each test series. The sheathing products included 12.7 mm (1/2 in) SI-Strong, 25.4 mm (1 in) SI-Strong, 12.7 mm (1/2 in) R-Max Thermasheath, and 2 mm (0.078 in) ThermoPly Green. The structural foam sheathing was attached per the manufacturers' specification to one side of the wood frame for each wall tested. Standard 12.7 mm (1/2 in) gypsum wallboard was screwed to the opposite side of the frame. Simpson HDQ8 tie-down anchors were screwed to the terminal studs at each end of the wall and anchored to the base of the testing apparatus. Both monotonic and cyclic testing following ASTM E564 and ASTM E2126, respectively, were considered. Results from the monotonic tests showed an 11 to 27 percent smaller capacity when compared to the published design values. Likewise, the test results from the cyclic tests showed a 24 to 45 percent smaller capacity than the published design values and did not meet the seismic performance design criteria computation.

Modal Characteristics of Control Element Assembly Shroud for Korean Standard Nuclear Power Plant(II : Test and Post-Test Analysis) (한국표준형 원자력발전소 제어봉집합체 보호구조물의 모우드 특성 II)

  • Jhung, Myung-Jo;Park, Keun-Bae;Song, Heuy-Gap;Choi, Suhn
    • Computational Structural Engineering
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    • v.5 no.4
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    • pp.93-102
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    • 1992
  • The design of reactor internals requires the accurate vibration characteristics of each component for subsequent dynamic structural response analyses. For Korean standard nuclear power plant some modifications on the Control Element Assembly shroud from the reference design have been made, Since the shroud is complex in geometry having an array of vertical round tubes and webs in a square grid pattern, and being tied down by preloaded tie rods into position, it is planned to perform a vibration measurement program consisting of both experimental and analytical modal studies upon that component. The shroud modal testing was performed on the low frequency global survey to measure the first several modes. The analysis using the finite element model was also performed for the as-tested conditions. The natural frequencies and mode shapes from both test and analysis have been acquired and compared to be in good agreement. It is concluded that finite element model generated is good enough to be used in the design for the dynamic response analysis under various loading conditions.

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