• Title/Summary/Keyword: BE(British Energy)

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Experimental and numerical investigation of RC sandwich panels with helical springs under free air blast loads

  • Rashad, Mohamed;Wahab, Mostafa M.A.;Yang, T.Y.
    • Steel and Composite Structures
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    • v.30 no.3
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    • pp.217-230
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    • 2019
  • One of the most important design criteria in underground structure is to design lightweight protective layers to resist significant blast loads. Sandwich blast resistant panels are commonly used to protect underground structures. The front face of the sandwich panel is designed to resist the blast load and the core is designed to mitigate the blast energy from reaching the back panel. The design is to allow the sandwich panel to be repaired efficiently. Hence, the underground structure can be used under repeated blast loads. In this study, a novel sandwich panel, named RC panel - Helical springs- RC panel (RHR) sandwich panel, which consists of normal strength reinforced concrete (RC) panels at the front and the back and steel compression helical springs in the middle, is proposed. In this study, a detailed 3D nonlinear numerical analysis is proposed using the nonlinear finite element software, AUTODYN. The accuracy of the blast load and RHR Sandwich panel modelling are validated using available experimental results. The results show that the proposed finite element model can be used efficiently and effectively to simulate the nonlinear dynamic behaviour of the newly proposed RHR sandwich panels under different ranges of free air blast loads. Detailed parameter study is then conducted using the validated finite element model. The results show that the newly proposed RHR sandwich panel can be used as a reliable and effective lightweight protective layer for underground structures.

A Comparison Study on the Importance and Problems of Assessment Items of the G-SEED System (G-SEED 평가항목별 중요도 및 문제점 비교연구)

  • Jang, Hyun-Sook;Lee, Sang-Ho
    • KIEAE Journal
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    • v.14 no.1
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    • pp.113-120
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    • 2014
  • The Green growth has been demanded in all industrial sectors due to environmental destruction and exhaustion of natural resources. Buildings have consumed 1/3 of the total energy and 40% of natural resources and have accounted for 50% of $CO_2$ emissions and 30-50% of waste materials. In 1991, BREEAM(Building Research Establishment Environmental Assessment Method) of the British BRE(Building Research Establishment) had begun reduction of $CO_2$ emissions and energy saving movements, in which all the countries around the world have participated. The Republic of Korea has taken part in this trend by declaring a "National Vision in the Green Growth" in 2008 and implementing regulations on "Low Carbon, Green Growth" in 2010. G-SEED(Green Standard for Energy and Environmental Design) based on GBCS(Green Building Certification System) has been actively promoted for its application. This study has limited its scope to G-SEED office buildings. It has conducted surveys of problems and assessment items of the G-SEED identified in the preceding study by the AHP(Analytic hierarchy process) method. The purpose of this study is to conduct a comparison analysis of problems and ranking of evaluation items recognized in the survey and to be presented as reference materials for G-SEED system improvements at its next amendments.

A Study on the Patterns of Subcultural Fashion Style (하위문화 패션스타일 유형(1))

  • 양미경
    • Journal of the Korea Fashion and Costume Design Association
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    • v.6 no.1
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    • pp.46-54
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    • 2004
  • In this paper, It is examined the patterns of fashion style in the history of subcultural clothing from 1930s to 1960s, focusing on the way each generation resisted the main stream through its styles. The subcultural styles examined and classified in this study are mainly British and American, with a few European and Western Indian styles included. This study understands subcultural style as a way of deviate or resistant expression within a society. The patterns of subcultural styles presented in this study are based on their form of resistance, and they are classified as follows: The pattern is revision, which tries to revise and change the given form by adding new elements. There are two kinds of revision, one is dressing up, which dresses for success, and the other is minimal dressing. Zoot, caribbean, western, teddy boy, rockabilly style are included here. As minimal dressing, there are hipster, beatnik, modernist, mod, rude boy style. In conclusion, it can be said that subcultural style puts the foremost importance on individual freedom. The new and significant development can be found in the fact that subcultural style emerges as a dominating force in our culture. This implies that the energy of a subculture is essential as a formative force of a fashion world.

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An Analysis of Operating Experience Reports on the Foreign JIT (해외 JIT에 수록된 운전경험 분석)

  • Lee, Sang-Hoon;Kim, Jae-Hun;Song, Tae-Young
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.10 no.1
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    • pp.70-74
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    • 2014
  • An Operating Experience Report(OER) has written about events and accidents happened at a Nuclear Power Plant(NPP). The purpose of publishing the OER is to prevent the similar event or accident repeatedly by spreading the experience of a single plant to other plants personnel. In this paper, it is analyses that the foreign NPPs' OERs on JIT published by the International Nuclear Agency(WANO, INPO, COG, BE). The analysis introduced in this paper is performed along with the various factors such as type of work, root-cause, and equipment. The root-cause analysis about the OERs shows that the Human-error is the major factor in foreign NPPs, but on the other hand equipment problem is the main part of the Domestic NPPs. The ratio of the foreign NPP's OERs on JIT according to the type of work was applied to KHNP-JIT developed nowadays for the first time in KOREA.

Evaluation of Dynamic Characteristics of Slipmeters with Force Platform (하중판을 이용한 미끄러짐 측정기의 동력학적 특성 평가)

  • Kim, Jung-Soo
    • Journal of the Korean Society of Safety
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    • v.27 no.5
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    • pp.1-8
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    • 2012
  • The purpose of this study were to evaluate the dynamic characteristics of the portable slipmeters with respect to actual slipping and to compare their output with those of force platform. The selected slipmeters were commonly used devices for slipperiness measurement in situ floors. Their output quantity represented force (BOT-3000), loss of energy(British pendulum striker) and angle of inclination(English XL). The validity of these devices was studied with respect to actual slipping using a force platform. The precision of these devices was also evaluated with force platform. Based on dynamics of human subject behavior when slipping during normal walking, the all devices tested in this study showed poor performances: low built up ratio, low normal pressure, and long contact time prior to slip. Nevertheless, their results reasonably correlated with those calculated from the ground reaction forces generated by the operation of the selected slipmeters on the force platform although the absolute values of COF from these three devices could be quite different. Also the results showed good repeatability under the some test conditions.

Seismic behaviour of repaired superelastic shape memory alloy reinforced concrete beam-column joint

  • Nehdi, Moncef;Alam, M. Shahria;Youssef, Maged A.
    • Smart Structures and Systems
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    • v.7 no.5
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    • pp.329-348
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    • 2011
  • Large-scale earthquakes pose serious threats to infrastructure causing substantial damage and large residual deformations. Superelastic (SE) Shape-Memory-Alloys (SMAs) are unique alloys with the ability to undergo large deformations, but can recover its original shape upon stress removal. The purpose of this research is to exploit this characteristic of SMAs such that concrete Beam-Column Joints (BCJs) reinforced with SMA bars at the plastic hinge region experience reduced residual deformation at the end of earthquakes. Another objective is to evaluate the seismic performance of SMA Reinforced Concrete BCJs repaired with flowable Structural-Repair-Concrete (SRC). A $\frac{3}{4}$-scale BCJ reinforced with SMA rebars in the plastic-hinge zone was tested under reversed cyclic loading, and subsequently repaired and retested. The joint was selected from an RC building located in the seismic region of western Canada. It was designed and detailed according to the NBCC 2005 and CSA A23.3-04 recommendations. The behaviour under reversed cyclic loading of the original and repaired joints, their load-storey drift, and energy dissipation ability were compared. The results demonstrate that SMA-RC BCJs are able to recover nearly all of their post-yield deformation, requiring a minimum amount of repair, even after a large earthquake, proving to be smart structural elements. It was also shown that the use of SRC to repair damaged BCJs can restore its full capacity.

Landscape Planning and Design Methods with Human Thermal Sensation (인간 열환경 지수(HumanThermal Sensation)를 이용한 조경계획 및 디자인 방법)

  • Park, Soo-Kuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.1
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    • pp.1-11
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    • 2012
  • Human thermal sensation based on a human energy balance model was analyzed in the study areas, the Changwon and Nanaimo sites, on clear days during thesummer of 2009. The climatic input data were air temperature, relative humidity, wind speed and solar and terrestrial radiation. The most effective factors for human thermal sensation were direct beam solar radiation, building view factor and wind speed. Shaded locations had much lower thermal sensation, slightly warm, than sunny locations, very hot. Also, narrow streets in the Nanaimo site had higher thermal sensation than open spaces because of greater reflected solar radiation and terrestrial radiation from their surrounding buildings. Calm wind speed also produced much higher thermal sensation, which reduced sensible and latent heat loss from the human body. By adopting climatic factors into landscape architecture, the human thermal sensation analysis method promises to help create thermally comfortable outdoor areas. The method can also be used for urban heat island modification and climate change studies.

ON CRACK INTERACTION EFFECTS OF IN-PLANE SURFACE CRACKS USING ELASTIC AND ELASTIC-PLASTIC FINITE ELEMENT ANALYSES

  • Kim, Jong-Min;Huh, Nam-Su
    • Nuclear Engineering and Technology
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    • v.42 no.6
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    • pp.680-689
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    • 2010
  • The crack-tip stress fields and fracture mechanics assessment parameters for a surface crack, such as the elastic stress intensity factor or the elastic-plastic J-integral, can be affected significantly by the adjacent cracks. Such a crack interaction effect due to multiple cracks can alter the fracture mechanics assessment parameters significantly. There are many factors to be considered, for instance the relative distance between adjacent cracks, the crack shape, and the loading condition, to quantify the crack interaction effect on the fracture mechanics assessment parameters. Thus, the current assessment codes on crack interaction effects (crack combination rules), including ASME Sec. XI, BS7910, British Energy R6 and API 579-1/ASME FFS-1, provide different rules for combining multiple surface cracks into a single surface crack. The present paper investigates crack interaction effects by evaluating the elastic stress intensity factor and the elastic-plastic J-integral of adjacent in-plane surface cracks in a plate through detailed 3-dimensional elastic and elastic-plastic finite element analyses. The effects on the fracture mechanics assessment parameters of the geometric parameters, the relative distance between two cracks, and the crack shape are investigated systematically. As for the loading condition, an axial tension is considered. Based on the finite element results, the acceptability of the crack combination rules provided in the existing guidance was investigated, and the relevant recommendations on a crack interaction for in-plane surface cracks are discussed. The present results can be used to develop more concrete guidance on crack interaction effects for crack shape characterization to evaluate the integrity of defective components.

Applying the Ferrocement Concept in Construction of Concrete Beams Incorporating Reinforced Mortar Permanent Forms

  • Fahmy, Ezzat H.;Shaheen, Yousry B.I.;Abdelnaby, Ahmed Mahdy;Abou Zeid, Mohamed N.
    • International Journal of Concrete Structures and Materials
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    • v.8 no.1
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    • pp.83-97
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    • 2014
  • This paper presents the results of an investigation aimed at developing reinforced concrete beams consisting of precast permanent U-shaped reinforced mortar forms filled with different types of core materials to be used as a viable alternative to the conventional reinforced concrete beam. To accomplish this objective, an experimental program was conducted and theoretical model was adopted. The experimental program comprised casting and testing of thirty beams of total dimensions $300{\times}150{\times}2,000mm$ consisting of permanent precast U-shaped reinforced mortar forms of thickness 25 mm filled with the core material. Three additional typical reinforced concrete beams of the same total dimensions were also cast to serve as control specimens. Two types of single-layer and double-layers steel meshes were used to reinforce the permanent U-shaped forms; namely welded wire mesh and X8 expanded steel mesh. Three types of core materials were investigated: conventional concrete, autoclaved aerated lightweight concrete brick, and recycled concrete. Two types of shear connections between the precast permanent reinforced mortar form and the core material were investigated namely; adhesive bonding layer between the two surfaces, and mechanical shear connectors. The test specimens were tested as simple beams under three-point loadings on a span of 1,800 mm. The behavior of the beams incorporating the permanent forms was compared to that of the control beams. The experimental results showed that better crack resistance, high serviceability and ultimate loads, and good energy absorption could be achieved by using the proposed beams which verifies the validity of using the proposed system. The theoretical results compared well with the experimental ones.

Effect of Feed Protein Source on Digestion and Wool Production in Angora Rabbit

  • Bhatt, R.S.;Sawal, R.K.;Mahajan, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.7
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    • pp.1075-1079
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    • 1999
  • Adult German cross $(German{\times}British{\times}Russian)$ angora rabbits (one year age), 32 in number were divided randomly into four groups $(T_1-T_4)$ with equal sex ratio and fed diets containing $T_1$ groundnut cake (GNC); $T_3$, soyaflakes (SF); $T_4$, sunflower cake (SFC) and $T_2$, a mixture of all the three cakes along with green forage as roughage for a period of 9 months. Nine per cent protein was added from each protein source. Fibre level was maintained by adjusting the level of rice phak in the diets. The diets were iso-nitrogenous and contained similar level of fibre. DMI through roughage was not affected due to source of protein in the diet, however, DMI through concentrate was higher $(p{\leq}0.05)$ with SFC diet, which resulted in higher total feed intake in the group $(T_4)$. Body weights increased up to second shearing, thereafter it decreased due to summer depression. Diet containing soyaflakes sustained higher wool yield whereas, it was lowest $(p{\leq}0.05)$ on SFC diet. Wool attributes (staple length, medullation, fibre diameter) were not affected due to source of protein in the diet. Digestibility of fibre and its fractions (ADF, cellulose, hemicellulose) decreased $(p{\leq}0.05)$ with incorporation of SFC in the diets. Balance of calcium was lowest whereas, that of nitrogen was highest with SFC diet $(T_4)$. Biological value of N and net protein utilization was better when different protein sources were mixed together $(T_2)$. Protein quality of soyaflakes proved better for wool production followed by groundnut cake and mixture of three protein sources. Sunflower cake alone or in combination decreased wool production which may be checked by supplementation of amino acids and energy.