• 제목/요약/키워드: Queensland

검색결과 383건 처리시간 0.031초

Integrated Model for Assessment of Risks in Rail Tracks under Various Operating Conditions

  • G. Chattopadhyay;V. Reddy;Larsson, P-O
    • International Journal of Reliability and Applications
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    • 제4권4호
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    • pp.183-190
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    • 2003
  • Rail breaks and derailments can cause a huge loss to rail players due to loss of service, revenue, property or even life. Maintenance has huge impact on reliability and safety of railroads. It is important to identify factors behind rail degradation and their risks associated with rail breaks and derailments. Development of mathematical models is essential for prediction and prevention of risks due to rail and wheel set damages, rail breaks and derailments. This paper addresses identification of hazard modes, estimation of probability of those hazards under operating, curve and environmental condition, probability of detection of potential hazards before happening and severity of those hazards for informed strategic decisions. Emphasis is put on optimal maintenance and operational decisions. Real life data is used for illustration.

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Pseudo plastic zone analysis of steel frame structures comprising non-compact sections

  • Avery, P.;Mahendran, M.
    • Structural Engineering and Mechanics
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    • 제10권4호
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    • pp.371-392
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    • 2000
  • Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.

Numerical investigation of mechanical properties of nanowires: a review

  • Gu, Y.T.;Zhan, H.F.;Xu, Xu
    • Interaction and multiscale mechanics
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    • 제5권2호
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    • pp.115-129
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    • 2012
  • Nanowires (NWs) have attracted intensive researches owing to the broad applications that arise from their remarkable properties. Over the last decade, immense numerical studies have been conducted for the numerical investigation of mechanical properties of NWs. Among these numerical simulations, the molecular dynamics (MD) plays a key role. Herein we present a brief review on the current state of the MD investigation of nanowires. Emphasis will be placed on the FCC metal NWs, especially the Cu NWs. MD investigations of perfect NWs' mechanical properties under different deformation conditions including tension, compression, torsion and bending are firstly revisited. Following in succession, the studies for defected NWs including the defects of twin boundaries (TBs) and pre-existing defects are discussed. The different deformation mechanism incurred by the presentation of defects is explored and discussed. This review reveals that the numerical simulation is an important tool to investigate the properties of NWs. However, the substantial gaps between the experimental measurements and MD results suggest the urgent need of multi-scale simulation technique.

Does subepineural injection damage the nerve integrity? A technical report from four amputated limbs

  • Diwan, Sandeep;Nair, Abhijit;Sancheti, Parag;Van Zundert, Andre
    • The Korean Journal of Pain
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    • 제34권1호
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    • pp.132-136
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    • 2021
  • Local anesthetic (LA) injection outside the sheath in epineural or paraneural connective tissue is considered safe practice among regional anesthesiologists. There is limited evidence as to whether neurological complications occur if LA is injected inside the sheath (subepineural - intraneural). We performed ultrasound guided injections at the level of undivided sciatic nerve in four amputated lower limbs. In two specimens, LA was injected in epineural connective tissue (paraneural tissue) and in another two specimens by penetrating the outer nerve sheath (hyperechoic epineurium). Ultrasonography demonstrated an increase in the size of nerve and macroscopic findings revealed fascicular tracings with sub-epineural injections. Limbs were sent for histological analysis in formalin containers. Pathologist performed the analysis which demonstrated an intact perineurium and a breach in the epineurium. We conclude that sub-epineural injections are unsafe and injection should be done in paraneural tissue to ensure safety and avoid unwanted neurological sequelae after the block.

RESPONDING TO GLOBAL ISSUES: SUSTAINABILITY AND INNOVATION IN THE AUSTRALIAN SME RESIDENTIAL BUILDING CONSTRUCTION SECTOR

  • D.S. Thorpe;N. Ryan
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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    • pp.684-693
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    • 2007
  • The construction industry is a significant component of many economies and typically contains a high proportion of small and medium enterprises. However, it is generally understood that this industry is fragmented, adversarial, not highly innovative and not quick to respond to change. At the same time, the industry is under pressure to continue to embrace new technologies and methods, and to adapt better to current and emerging global issues such as sustainability. In order to meet these challenges, firms in the industry need to understand the issues involved and manage their practices accordingly. This paper describes exploratory research into the role of innovative and environmentally sustainable design and construction practices in one group of construction firms, viz., smaller residential building firms in Queensland, Australia.

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IMPLEMENTING WEB-BASED COLLABORATION PLATFORMS IN CONSTRUCTION: EVALUATING THE LANE COVE TUNNEL (LCT) EXPERIENCE

  • Rodney A. Stewart ;Debbie Smit ;Martin Betts
    • 국제학술발표논문집
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    • The 1th International Conference on Construction Engineering and Project Management
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    • pp.544-549
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    • 2005
  • Web-based collaboration platforms present construction project teams with an opportunity to improve the efficiency of document exchange, better control project communications and enhance team collaboration. However, many construction professionals are still not convinced that these platforms, in their current form, are fit-for-purpose and yield sufficient efficiencies for the construction procurement process. In an attempt to improve the current ICT diffusion process, this paper evaluates the implementation of a web-based collaboration tool on the Lane Cove Tunnel (LCT) project in Sydney, Australia. Moreover, the paper provides strategies for achieving more effective implementation of web-based collaboration platforms in the construction sector.

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