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Article
Publication date: 1 December 2004

Tommy Y. Lo and K.T.W. Choi

The application of infrared thermography has provided a reliable and accurate assessment method for the inspection of buildings and structures. The principle of the…

Abstract

The application of infrared thermography has provided a reliable and accurate assessment method for the inspection of buildings and structures. The principle of the infrared thermography technique is the detection of energy by an infrared scanner and mapping the temperature contours over the surface of a target object to provide an appropriate measure of the damaged building or structure. This paper reviews the background of infrared thermography and the factors influencing the IR imaging. The applicability of infrared thermography in two particular situations is considered – the delamination of external wall finishes and a roofing system condition survey.

Details

Structural Survey, vol. 22 no. 5
Type: Research Article
ISSN: 0263-080X

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Article
Publication date: 1 November 2018

Kinjiro Amano, Eric C.W. Lou and Rodger Edwards

Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of benefits in terms…

Abstract

Purpose

Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of benefits in terms of achieving the efficient design, construction, operation and maintenance of buildings. Applying BIM at the outset of a new build project should be relatively easy. However, it is often problematic to apply BIM techniques to an existing building, for example, as part of a refurbishment project or as a tool supporting the facilities management strategy, because of inadequacies in the previous management of the dataset that characterises the facility in question. These inadequacies may include information on as built geometry and materials of construction. By the application of automated retrospective data gathering for use in BIM, such problems should be largely overcome and significant benefits in terms of efficiency gains and cost savings should be achieved.

Design/methodology/approach

Laser scanning can be used to collect geometrical and spatial information in the form of a 3D point cloud, and this technique is already used. However, as a point cloud representation does not contain any semantic information or geometrical context, such point cloud data must refer to external sources of data, such as building specification and construction materials, to be in used in BIM.

Findings

Hyperspectral imaging techniques can be applied to provide both spectral and spatial information of scenes as a set of high-resolution images. Integrating of a 3D point cloud into hyperspectral images would enable accurate identification and classification of surface materials and would also convert the 3D representation to BIM.

Originality/value

This integrated approach has been applied in other areas, for example, in crop management. The transfer of this approach to facilities management and construction would improve the efficiency and automation of the data transition from building pathology to BIM. In this study, the technological feasibility and advantages of the integration of laser scanning and hyperspectral imaging (the latter not having previously been used in the construction context in its own right) is discussed, and an example of the use of a new integration technique is presented, applied for the first time in the context of buildings.

Details

Journal of Facilities Management, vol. 17 no. 1
Type: Research Article
ISSN: 1472-5967

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Article
Publication date: 1 February 2000

Jerzy P. Komorowski and David S. Forsyth

The current corrosion maintenance philosophy reflected in aviation regulations and recommended practices does not stimulate progress in corrosion related technology. A US…

Abstract

The current corrosion maintenance philosophy reflected in aviation regulations and recommended practices does not stimulate progress in corrosion related technology. A US Air Force (USAF)‐sponsored survey has recommended re‐examination of corrosion maintenance policies and practices to identify lower cost alternatives, and has encouraged research into tools and techniques that reduce maintenance costs while preserving safety. In particular, these include models to predict the impact of existing corrosion damage on structural integrity, methods of predicting corrosion growth rates and nondestructive inspection systems capable of providing corrosion metrics. The Institute for Aerospace Research of the National Research Council Canada (IAR/NRC) has pioneered work on the application of enhanced visual methods for corrosion detection in lap joints and the assessment of the impact of corrosion on lap‐joint structural integrity. The role of these enhanced visual methods in the new corrosion management is described.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

Content available
Article
Publication date: 1 February 2001

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 73 no. 1
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 14 May 2019

Mehdi Zare and Sadegh Sadeghi

This study aims to perform a comprehensive investigation to model the thermal characteristics of a coupled conduction-radiation heat transfer in a two-dimensional…

Abstract

Purpose

This study aims to perform a comprehensive investigation to model the thermal characteristics of a coupled conduction-radiation heat transfer in a two-dimensional irregular enclosure including a triangular-shaped heat source.

Design/methodology/approach

For this purpose, a promising hybrid technique based on the concepts of blocked-off method, FVM and DOM is developed. The enclosure consists of several horizontal, vertical and oblique walls, and thermal conductivity within the enclosure varies directly with temperature and indirectly with position. To simplify the complex geometry, a promising mathematical model is introduced using blocked-off method. Emitting, absorbing and non-isotropic scattering gray are assumed as the main radiative characteristics of the steady medium.

Findings

DOM and FVM are, respectively, applied for solving radiative transfer equation (RTE) and the energy equation, which includes conduction, radiation and heat source terms. The temperature and heat flux distributions are calculated inside the enclosure. For validation, results are compared with previous data reported in the literature under the same conditions. Results and comparisons show that this approach is highly efficient and reliable for complex geometries with coupled conduction-radiation heat transfer. Finally, the effects of thermo-radiative parameters including surface emissivity, extinction coefficient, scattering albedo, asymmetry factor and conduction-radiation parameter on temperature and heat flux distributions are studied.

Originality/value

In this paper, a hybrid numerical method is used to analyze coupled conduction-radiation heat transfer in an irregular geometry. Varying thermal conductivity is included in this analysis. By applying the method, results obtained for temperature and heat flux distributions are presented and also validated by the data provided by several previous papers.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 April 1989

T.C. Chung and H.A. Moore

Tape automated bonding (TAB) is one technology which is becoming widely adopted for interconnecting integrated circuits to a substrate or package. Both destructive and…

Abstract

Tape automated bonding (TAB) is one technology which is becoming widely adopted for interconnecting integrated circuits to a substrate or package. Both destructive and non‐destructive test methods for evaluation of TAB bonds are analysed and criticised. The key parameters and general guidelines of a destructive beampull test set‐up are identified and presented. The key features of four different non‐destructive test methods are described and discussed. It is found that no universal solution exists for non‐destructive evaluation of TAB bonds although some methods may be more useful than others under certain conditions and constraints. Data and experimental procedure are presented for correlation of scanning laser acoustic microscopy and beampull data.

Details

Circuit World, vol. 16 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 January 1978

S.S.M. Wang and P.M. Will

This paper describes many sensors which are applicable to the requirements of the computer controlled assembly and manufacturing process. Various new types of sensors are…

Abstract

This paper describes many sensors which are applicable to the requirements of the computer controlled assembly and manufacturing process. Various new types of sensors are presented including a multi‐degree of freedom force sensor using interchangeable modules, a pneumatic retractable whisker, an ultrasonic probe and various tactile and optical image sensors.

Details

Industrial Robot: An International Journal, vol. 5 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 9 August 2011

Nasiru Idris Medugu, M. Rafee Majid and Foziah Johar

This paper seeks to review the state of desertification in Nigeria, historical trends and past national efforts as well as ongoing programs for combating the…

Abstract

Purpose

This paper seeks to review the state of desertification in Nigeria, historical trends and past national efforts as well as ongoing programs for combating the fast-spreading desert conditions in the arid zones of the country.

Design/methodology/approach

The approach has been carried out through a comprehensive review analysis and detailed assessment on several methods of approach which includes archival materials as well as published government documents, field observation and learned background information of the working and funding dynamics of the program to combat desertification.

Findings

The findings of this paper reveal that the failure of the past government effort in combating desertification in Nigeria is a result of the policies and the programs not having been designed to adequately tackle the problem of drought and desertification and of the phenomena being treated as sectoral issues rather than an integrated whole.

Practical implications

This paper has practical implication for anyone interested in sustainable management of drought and desertification in the arid and semi arid zones of the world.

Originality/value

The paper has articulated success and failure of the government programs in combating the twin environmental problems of drought and desertification in Nigeria and also shows that government could significantly combat desertification through sustainable management of its projects/programs if adequate resources are employed.

Details

Management of Environmental Quality: An International Journal, vol. 22 no. 5
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 16 April 2018

Ravinder Singh and Kuldeep Singh Nagla

Accurate perception of the environment using range sensors such as laser scanner, SONAR, infrared, vision, etc., for the application, such as path planning, localization…

Abstract

Purpose

Accurate perception of the environment using range sensors such as laser scanner, SONAR, infrared, vision, etc., for the application, such as path planning, localization, autonomous navigation, simultaneously localization and mapping, is a highly challenging area. The reliability of the perception by range sensors relies on the sensor accuracy, precision, sensor model, sensor registration, resolution, etc. Laser scanner is even though accurate and precise but still the efficient and consistent mapping of the environment is yet to be attained because laser scanner gives error as the extrinsic and intrinsic parameters varied which cause specular reflection, refraction, absorption, etc., of the laser beam. The paper aims to discuss this issue.

Design/methodology/approach

This paper presents an error analysis in sensory information of laser scanner due to the effect of varying the scanning angle with respect to the optical axis and surface reflectivity or refractive index of the targets. Uncertainties caused by these parameters are reduced by proposing a new technique, tilt mounting system (TMS) with designed filters of tilting the angular position of a laser scanner with the best possible selection of range and scanning angle for the robust occupancy grid mapping. Various experiments are performed in different indoor environments, and the results are validated after the implementation of the TMS approach with designed filters.

Findings

After the implementation of the proposed TMS approach with filters, the errors in the laser grid map are reduced by 15.6 percent, which results in 62.5 percent reduction in the collision of a mobile robot during autonomous navigation in the laser grid map.

Originality/value

The TMS approach with designed filter reduces the effect of variation in intrinsic and extrinsic parameters to generate efficient laser occupancy grid map to achieve collision-free autonomous navigation.

Details

International Journal of Intelligent Unmanned Systems, vol. 6 no. 2
Type: Research Article
ISSN: 2049-6427

Keywords

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Article
Publication date: 5 October 2010

Florencia Edith Wiria, Kah Fai Leong and Chee Kai Chua

Tissue engineering (TE) involves biological, medical and engineering expertise and a current engineering challenge is to provide good TE scaffolds. These highly porous 3D…

Abstract

Purpose

Tissue engineering (TE) involves biological, medical and engineering expertise and a current engineering challenge is to provide good TE scaffolds. These highly porous 3D scaffolds primarily serve as temporal holding devices for cells that facilitate structural and functional tissue unit formation of the newly transplanted cells. One method used successfully to produce scaffolds is that of rapid prototyping. Selective laser sintering (SLS) is one such versatile method that is able to process many types of polymeric materials and good stability of its products. The purpose of this paper is to present modeling of the heat transfer process, to understand the sintering phenomena that are experienced by powder particles in the SLS powder bed during the sintering process. With the understanding of sintering process obtained through the theoretical modeling, experimental process of biomaterials in SLS could be directed towards the appropriate sintering window, so as not to cause unintentional degradation to the biomaterials.

Design/methodology/approach

SLS uses a laser as a heat source to sinter parts. A theoretical study based on heat transfer phenomena during SLS process was carried out. The study identified the significant biomaterial and laser beam properties that were critical to the sintering result. The material properties were thermal conductivity, thermal diffusivity, surface reflectivity and absorption coefficient.

Findings

The influential laser beam properties were laser power and scan speed, which were machine parameters that can be controlled by users. The identification of the important parameters has ensured that favorable sintering conditions can be achieved.

Research limitations/implications

The selection of biopolymer influences the manner in which energy is absorbed by the powder bed during the SLS process. In this paper, the modeling and investigative work was validated by poly(vinyl alcohol) which is a biomaterial that has been used for many biomedical and pharmaceutical purposes.

Practical implications

The paper can be the foundation for extension to other types of biomaterials including biopolymers, bioceramics and biocomposites.

Originality/value

The formulation of the theory for heat transfer phenomena during the SLS process is of significant value to any studies in using SLS for biomedical applications.

Details

Rapid Prototyping Journal, vol. 16 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

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