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1 – 10 of over 283000J.M.A. Cesar de Sa and D.R.J. Owen
The application of numerical techniques to the solution of practical problems which exist in rubber technology is described. Structures and components in the form of reinforced…
Abstract
The application of numerical techniques to the solution of practical problems which exist in rubber technology is described. Structures and components in the form of reinforced rubber shells are widely used in industry and prediction of their performance is complicated by both the anisotropic nature of composite construction and the incompressible behaviour of the basic material. A layered shell element is developed for the solution of such problems with general anisotropic behaviour independently permitted in each layer. The approach adopted permits the easy location of reinforcement patterns. Numerical solution is based on a single field formulation by eliminating at integrating point level the Lagrange multiplier imposing the incompressible constraint. Large deformation, including large rotation, behaviour is accommodated and a total Lagrangian solution process is adopted. The code developed permits the simulation of non‐conservative loading and its versatility is demonstrated by the solution of some practical examples.
Dandan Qiu, Lei Luo, Songtao Wang, Bengt Ake Sunden and Xinhong Zhang
This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet…
Abstract
Purpose
This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing.
Design/methodology/approach
Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed.
Findings
It is found that an obvious backflow occurs near the upper wall. Both the local and averaged Nusselt numbers considered in the defined region respond positively to the Rej. The surface curvature plays a positive role in increasing the averaged Nusselt number for smaller surface curvature (4-15) but affects little as the surface curvature is large enough (> 15). The thermal performance is larger for smaller surface curvature and changes little as the surface curvature is larger than 15. The jet to target spacing shows a negative effect in heat transfer enhancement and thermal performance.
Originality/value
The surface curvature effects are conducted by verifying the concave surface with constant jet size. The flow characteristics are first obtained for the confined impingement cases. Then confined and unconfined slot jet impingements are compared. An ineffective point for surface curvature effects on heat transfer and thermal performance is obtained.
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Vivekanand Venkataraman, Syed Usmanulla, Appaiah Sonnappa, Pratiksha Sadashiv, Suhaib Soofi Mohammed and Sundaresh S. Narayanan
The purpose of this paper is to identify significant factors of environmental variables and pollutants that have an effect on PM2.5 through wavelet and regression analysis.
Abstract
Purpose
The purpose of this paper is to identify significant factors of environmental variables and pollutants that have an effect on PM2.5 through wavelet and regression analysis.
Design/methodology/approach
In order to provide stable data set for regression analysis, multiresolution analysis using wavelets is conducted. For the sampled data, multicollinearity among the independent variables is removed by using principal component analysis and multiple linear regression analysis is conducted using PM2.5 as a dependent variable.
Findings
It is found that few pollutants such as NO2, NOx, SO2, benzene and environmental factors such as ambient temperature, solar radiation and wind direction affect PM2.5. The regression model developed has high R2 value of 91.9 percent, and the residues are stationary and not correlated indicating a sound model.
Research limitations/implications
The research provides a framework for extracting stationary data and other important features such as change points in mean and variance, using the sample data for regression analysis. The work needs to be extended across all areas in India and for various other stationary data sets there can be different factors affecting PM2.5.
Practical implications
Control measures such as control charts can be implemented for significant factors.
Social implications
Rules and regulations can be made more stringent on the factors.
Originality/value
The originality of this paper lies in the integration of wavelets with regression analysis for air pollution data.
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The purpose of this paper is to develop a subgrid-scale (SGS) model for large eddy simulation (LES) of buoyancy- and thermally driven transitional and turbulent flows and further…
Abstract
Purpose
The purpose of this paper is to develop a subgrid-scale (SGS) model for large eddy simulation (LES) of buoyancy- and thermally driven transitional and turbulent flows and further examine its performance.
Design/methodology/approach
Favre-filtered, non-dimensional LES equations are solved using non-dissipative, fully implicit, kinetic energy conserving, finite-volume algorithm which uses an iterative predictor-corrector approach based on pressure correction. Also, to develop a new SGS model which accounts for buoyancy, turbulent generation term in SGS viscosity is properly modified and enhanced by buoyancy production.
Findings
The proposed model has been successfully applied to turbulent Rayleigh–Bénard convection. The results show that the model is able to reproduce the complex physics of turbulent thermal convection. In comparison with the original wall-adapting local eddy-viscosity (WALE) and buoyancy-modified (BM) Smagorinsky models, turbulent diagnostics predicted by the new model are in better agreement with direct numerical simulation.
Originality/value
A BM variant of the WALE SGS model is newly developed and analyzed.
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Jamshid Beheshti, Mohammed J. AlGhamdi, Charles Cole, Dhary Abuhimed and Isabelle Lamoureux
The chapter describes a four-year research project, the objective of which was to design and develop an intervention tool to assist middle school students in their information…
Abstract
Purpose
The chapter describes a four-year research project, the objective of which was to design and develop an intervention tool to assist middle school students in their information seeking when engaged in an inquiry-based learning project.
Methodology/approach
Bonded design method was used to design a proof-of-concept (POC) low-tech Guide, and focus group and Informant Design methods were utilized to develop a Web Guide.
Findings
In creating an intervention tool, whether low-tech paper-based or high-tech websites, different methodologies that relied heavily on the participation of students in the design process were successfully utilized.
Practical implications
The research shows that participation of children and adolescents in designing the content of technology for educational use is imperative.
Originality/value
This is a long-term research project, which is unparalleled and unique in its scope, duration, breadth, and depth. Having access to the grade eight classes in a single school over a four-year period has proven to be a remarkable research opportunity, seldom reported in the literature.
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Robert Detmering, Anna Marie Johnson, Claudene Sproles, Samantha McClellan and Rosalinda Hernandez Linares
– The purpose of this paper is to provide a selected bibliography of recent resources on library instruction and information literacy.
Abstract
Purpose
The purpose of this paper is to provide a selected bibliography of recent resources on library instruction and information literacy.
Design/methodology/approach
Introduces and annotates English-language periodical articles, monographs and other materials on library instruction and information literacy published in 2013.
Findings
Provides information about each source, discusses the characteristics of current scholarship and describes sources that contain unique scholarly contributions and quality reproductions.
Originality/value
The information may be used by librarians and interested parties as a quick reference to literature on library instruction and information literacy.
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BRIAN VICKERY and ALINA VICKERY
There is a huge amount of information and data stored in publicly available online databases that consist of large text files accessed by Boolean search techniques. It is widely…
Abstract
There is a huge amount of information and data stored in publicly available online databases that consist of large text files accessed by Boolean search techniques. It is widely held that less use is made of these databases than could or should be the case, and that one reason for this is that potential users find it difficult to identify which databases to search, to use the various command languages of the hosts and to construct the Boolean search statements required. This reasoning has stimulated a considerable amount of exploration and development work on the construction of search interfaces, to aid the inexperienced user to gain effective access to these databases. The aim of our paper is to review aspects of the design of such interfaces: to indicate the requirements that must be met if maximum aid is to be offered to the inexperienced searcher; to spell out the knowledge that must be incorporated in an interface if such aid is to be given; to describe some of the solutions that have been implemented in experimental and operational interfaces; and to discuss some of the problems encountered. The paper closes with an extensive bibliography of references relevant to online search aids, going well beyond the items explicitly mentioned in the text. An index to software appears after the bibliography at the end of the paper.
Barbara A. Norgard, Michael G. Berger and Christian Plaunt
Jin Zhang, Ming Ren, Xian Xiao and Jilong Zhang
The purpose of this paper is to find a representative subset from large-scale online reviews for consumers. The subset is significantly small in size, but covers the majority…
Abstract
Purpose
The purpose of this paper is to find a representative subset from large-scale online reviews for consumers. The subset is significantly small in size, but covers the majority amount of information in the original reviews and contains little redundant information.
Design/methodology/approach
A heuristic approach named RewSel is proposed to successively select representatives until the number of representatives meets the requirement. To reveal the advantages of the approach, extensive data experiments and a user study are conducted on real data.
Findings
The proposed approach has the advantage over the benchmarks in terms of coverage and redundancy. People show preference to the representative subsets provided by RewSel. The proposed approach also has good scalability, and is more adaptive to big data applications.
Research limitations/implications
The paper contributes to the literature of review selection, by proposing a heuristic approach which achieves both high coverage and low redundancy. This study can be applied as the basis for conducting further analysis of large-scale online reviews.
Practical implications
The proposed approach offers a novel way to select a representative subset of online reviews to facilitate consumer decision making. It can also enhance the existing information retrieval system to provide representative information to users rather than a large amount of results.
Originality/value
The proposed approach finds the representative subset by adopting the concept of relative entropy and sentiment analysis methods. Compared with state-of-the-art approaches, it offers a more effective and efficient way for users to handle a large amount of online information.
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