8,903 research outputs found
Nature of band-gap states in V-doped TiO2 revealed by resonant photoemission
Band-gap states in V-doped TiO2 have been studied by photoemission spectroscopy over a range of photon energies encompassing the Ti 3p and V 3p core thresholds. The states show resonant enhancement at photon energies significantly higher than found for Ti 3d states introduced into TiO2 by oxygen deficiency or alkalimetal adsorbates. This demonstrates that the gap states relate to electrons trapped on dopant V cations rather than host Ti cations
Developing a Tailored RBS Linking to BIM for Risk Management of Bridge Projects
Purpose – The purpose of this paper is to address the current theoretical gap in integrating knowledge and experience into Building Information Model (BIM) for risk management of bridge projects by developing a tailored Risk Breakdown Structure (RBS) and formalising an active link between the resulting RBS and BIM. Design/methodology/approach – A three-step approach is used in this study to develop a tailored RBS for bridge projects and a conceptual model for the linkage between the RBS and BIM. First, the integrated bridge information model is in concept separated into four levels of contents (LOCs) and six technical systems based on analysis of the Industry Foundation Classes specification, a critical review of previous studies and authors’ project experience. The second step develops a knowledge-based risk database through an extensive collection of risk data, a process of data mining, and further assessment and translation of data. A critical analysis is conducted in the last step to determine on which level the different risks should be allocated to bridge projects and to propose a conceptual model for linking the tailored RBS to the four LOCs and six technical systems of BIM. Findings – The findings suggest that the traditional method and BIM can be merged as an integrated solution for risk management by establishing the linkage between RBS and BIM. This solution can take advantage of both the traditional method and BIM for managing risks. On the one hand, RBS enables risk information to be stored in a formal structure, used and communicated effectively. On the other hand, some features of BIM such as 3D visualisation and 4D construction scheduling can facilitate the risk identification, analysis, and communication at an early project stage. Research limitations/implications – A limitation is that RBS is a qualitative technique and only plays a limited role in quantitative risk analysis. As a result, when implementing this proposed method, further techniques may be needed for assisting quantitative risk analysis, evaluation, and treatment. Another limitation is that the proposed method has not yet been implemented for validation in practice. Hence, recommendations for future research are to: improve the quantitative risk analysis and treatment capabilities of this proposed solution; develop computer tools to support the solution; integrate the linkage into a traditional workflow; and test this solution in some small and large projects for validation. Practical implications – Through linking risk information to BIM, project participants could check and review the linked information for identifying potential risks and seeking possible mitigation measures, when project information is being transferred between different people or forwarded to the next phase. Originality/value – This study contributes to the theoretical development for aligning traditional methods and BIM for risk management, by introducing a new conceptual model for linking RBS to BIM
Lateral impact response of the concrete filled steel tube columns with and without CFRP strengthening
BIM business value for asset owners through effective asset information management
The purpose of this paper is to investigate the processes, tools and techniques of strategic asset information management (AIM) for built assets, and how the asset information content enhances the proficiency of asset managers to effectively manage their assets throughout their life cycle by utilising building information modelling (BIM) and asset management (AM) systems. For most asset managers, the problem is not the lack of information about their assets, but the abundance of it, and most especially the absence of established processes and protocols to effectively manage large sets of asset data. Therefore, it is crucial to develop a strategy to control and manage this information in order for asset managers to harness its potential and realise value from their organisation’s information assets. A qualitative case study strategy was used to investigate the effective management of asset data in an AIM system. Seven sets of interviews were conducted and nine respondents were interviewed. These were analysed through qualitative thematic analysis using the NVivo software. The paper identifies six dimensions of value that BIM contributes to AM, which are: management, commerce, efficiency, industry, user and technology value. Also, the paper demonstrates that there is real value to be derived by the asset owner from the effective management of asset information. The study highlights that the value of BIM is not inherent but would require many other processes to deliver value to the organisation. The key value of the paper is that it identifies important techniques for managing asset data and how asset information is collected, organised, stored, controlled, analysed, secured, shared and reported within a virtual AIM system for strategic management-based decision
BIM business value generation theory : a grounded theory approach
Theoretical developments in the Architectural Engineering and Construction (AEC) industry have been deficient, especially for the operations and use phase. The need for asset owners to understand the Building Information Modelling (BIM) process and to realise business value from BIM implementation cannot be over emphasised. This study investigates a BIM-based Asset Management (AM) system to examine how business value can be created for the asset owner. The BIM-based AM system is evaluated from the Transformation-Flow-Value (TFV) generation view to define the characteristics and functions. This is followed by the grounding of data to develop a novel explanatory theory through the development of conceptual categories. A qualitative research approach based on a grounded theory methodology is utilised to generate a proposition on how BIM can create value in an AM system. The study involves a five-stage research design using interviews and document analysis to inform the phenomenon of BIM business value creation in AM. The paper highlights that BIM business value generation in AM is dependent on three main categories, which are: development of the information requirements, creation of the information content and management of the information content. From the grounded data, the study finds that it is crucial for asset owners to develop their information requirements since the information requirements development category guides the data creation, data management and value generation. Furthermore, the development of a sound rationale that appropriately translates the organisational business objectives is critical to value generation. The paper studies how BIM can create business value in an AM system using a grounded theory methodology. The results show that the rationale for developing BIM-based information requirements determines the value that will be generated by the AM system. The key contribution of the paper is that it presents a novel theory for BIM-based AM. One of the contributions of this study is the demonstration of the application of grounded theory within the AEC industry. Also, the study demonstrates the relationships between concepts and how they emerge from the grounded data
Lateral impact response of end-plate beam-column connections
The behaviour of different steel beam to column connections has been studied intensively against static and seismic loading regimes. However, there is a lack of knowledge on the response of such connections against impact and blast. In order to close this gap, the most common connections with partially depth end plate (PDEPCs), as a simple connection, and flush plate (FPCs), as a moment resisting connection, were investigated under both quasi-static and impact loads. Here, eight specimens were tested under those loading conditions with different locations. 3 D finite element models were then developed and validated against the corresponding experimental results. Full range analyses of the connection responses under both loading regimes are then carried out using the validated FE models to examine the internal forces of the connections. Finally, the results of full analyses under both loading regimes were compared and dynamic increase factors (DIF) were proposed to assist predicting the impact response of these types of connections using the static analysis. The results showed that failure modes under both loading regimes were similar, but with the larger fracture on the PDEPC under quasi-static load than that under lateral impact. The DIFs were found to be between 1.02 and 1.21, 1.03 and 1.36 and 1.22 and 1.45 based on the bolt tensile strength, axial resistance and bending resistance of the connections, respectively. However, if based on the energy approach, the range of DIFs was recorded between 1.25 and 1.38 using the experimental results and between 1.19 and 1.34 using the finite element analysis results
Vertexicola caudatus gen. et sp. nov., and a new species of Rivulicola from submerged wood in freshwater habitats
Vertexicola caudatus gen. et sp. nov., is described and illustrated from sibmerged wood collected from a creek in the Philippines and a river in Hong Kong. Vertexicola differs from other genera in the Annulatascaceae (Sordariales) in having thickwalled distoseptate ascospores and asci with a tail-like structure. The placement of Vertexicolawithin the Annulatascaceae is discussed and it is compared with other genera in this family. Rivulicola aquatica sp. nov. is also described and illustrated.published_or_final_versio
Development of a BIMAsset Maturity Model
This paper presents a BIMAsset Maturity Model (BAMM) which demonstrates how asset owners can appraise the maturity of their organisations in relation to their capability of realising Building Information Modelling (BIM) business value in Asset Management (AM). The study aims to develop and enhance the understanding of asset owners in relation to techniques of appraising key business processes that help derive BIM business value during asset operations. The study utilises a qualitative multi-case study strategy to develop a maturity model that is specific to the domains of BIM, AM and value realisation management. Also, this study adopts an inductive approach using semi-structured interviews to collect data. Furthermore, an expert panel in the form of a focus group is utilised to validate the BAMM. This study finds that the ability of asset owners to derive BIM business value during asset operations has maturity implications in relation to certain key business processes. Furthermore, the study reveals that business value can be derived by the asset owner if organisational processes such as BIM strategy, contract management, lifecycle management, maintenance management, work-order management and value realisation management are effectively executed and continuously improved to an advanced stage of maturity. An important contribution of the paper is that it presents a novel approach for evaluating owner-operator organisations using the BAMM from two perspectives; AM business processes (BIM strategy, contract management, lifecycle management, maintenance management, work-order management and value realisation management); and BIM governance dimensions (people, process and technology)
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