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1 – 10 of over 4000The reasons for the essential drying of electronic components are enumerated prior to a description of several drying methods currently employed in industry. A process involving…
Abstract
The reasons for the essential drying of electronic components are enumerated prior to a description of several drying methods currently employed in industry. A process involving drying with fluorocarbons that utilises a water displacement system is found to perform efficiently. The displacement effect is outlined and the benefits of using this system with fluorocarbon solvents are listed. Various applications exist in the electronics field for which this method proves to offer marked advantages.
Wei-Hai Yuan, Wei Zhang, Beibing Dai and Yuan Wang
Large deformation problems are frequently encountered in various fields of geotechnical engineering. The particle finite element method (PFEM) has been proven to be a promising…
Abstract
Purpose
Large deformation problems are frequently encountered in various fields of geotechnical engineering. The particle finite element method (PFEM) has been proven to be a promising method to solve large deformation problems. This study aims to develop a computational framework for modelling the hydro-mechanical coupled porous media at large deformation based on the PFEM.
Design/methodology/approach
The PFEM is extended by adopting the linear and quadratic triangular elements for pore water pressure and displacements. A six-node triangular element is used for modelling two-dimensional problems instead of the low-order three-node triangular element. Thus, the numerical instability induced by volumetric locking is avoided. The Modified Cam Clay (MCC) model is used to describe the elasto-plastic soil behaviour.
Findings
The proposed approach is used for analysing several consolidation problems. The numerical results have demonstrated that large deformation consolidation problems with the proposed approach can be accomplished without numerical difficulties and loss of accuracy. The coupled PFEM provides a stable and robust numerical tool in solving large deformation consolidation problems. It is demonstrated that the proposed approach is intrinsically stable.
Originality/value
The PFEM is extended to consider large deformation-coupled hydro-mechanical problem. PFEM is enhanced by using a six-node quadratic triangular element for displacement and this is coupled with a four-node quadrilateral element for modelling excess pore pressure.
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H.R. Thomas and C.H. Liu
The implementation of the finite element solution of Biot's consolidation theory on a low‐cost microcomputer is described. A two‐dimensional linear elastic model is solved using…
Abstract
The implementation of the finite element solution of Biot's consolidation theory on a low‐cost microcomputer is described. A two‐dimensional linear elastic model is solved using bilinear rectangular elements and a fully implicit timestepping algorithm. The machine used is the Acorn Computers model B, BBC microcomputer, a popular low‐cost engineering applications machine. The program is written in Basic but to increase speed of computation certain sections of the solution procedure involving matrix manipulation are written in Assembly language. The results obtained are encouraging from the point of view of accuracy, problem size and computational time. It is concluded that there is scope for the use of the present generation of low‐cost microcomputer, as typified by this machine, in the numerical solution of the more straightforward, but still realistic, consolidation problems.
Temporary corrosion preventives based on petroleum are applied to a great variety of products ranging from ball bearings to sheet steel to give protection during manufacture…
Abstract
Temporary corrosion preventives based on petroleum are applied to a great variety of products ranging from ball bearings to sheet steel to give protection during manufacture, transport or storage. In this article the author describes the main types of preventives, their selection for particular purposes, methods of application, the types of and mode of action of inhibitors added to the preventives and, finally, methods of testing.
Anna Trubetskaya, Olivia McDermott and Seamus McGovern
This article aims to optimise energy use and consumption by integrating Lean Six Sigma methodology with the ISO 50001 energy management system standard in an Irish dairy plant…
Abstract
Purpose
This article aims to optimise energy use and consumption by integrating Lean Six Sigma methodology with the ISO 50001 energy management system standard in an Irish dairy plant operation.
Design/methodology/approach
This work utilised Lean Six Sigma methodology to identify methods to measure and optimise energy consumption. The authors use a single descriptive case study in an Irish dairy as the methodology to explain how DMAIC was applied to reduce energy consumption.
Findings
The replacement of heavy oil with liquid natural gas in combination with the new design of steam boilers led to a CO2 footprint reduction of almost 50%.
Practical implications
A further longitudinal study would be useful to measure and monitor the energy management system progress and carry out more case studies on LSS integration with energy management systems across the dairy industry.
Originality/value
The novelty of this study is the application of LSS in the dairy sector as an enabler of a greater energy-efficient facility, as well as the testing of the DMAIC approach to meet a key objective for ISO 50001 accreditation.
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A new range of mechanical lubricating equipment is now being manufactured in Great Britain. This is the result of an agreement between Davies & Metcalfe Ltd., Romiley, Stockport…
Abstract
A new range of mechanical lubricating equipment is now being manufactured in Great Britain. This is the result of an agreement between Davies & Metcalfe Ltd., Romiley, Stockport, and Alex. Friedmann, Vienna. The latter company have manufactured high class mechanical lubricators and accessories for very many years and are well known in most parts of the world.
Bingqi Li, Zhenyu Zhang, Xiaogang Wang and Xiaonan Liu
The behavior of joints has a significant effect on the stability of water conveyance tunnel. The purpose of this paper is to study the contact and friction at the joint of the…
Abstract
Purpose
The behavior of joints has a significant effect on the stability of water conveyance tunnel. The purpose of this paper is to study the contact and friction at the joint of the tunneling segment lining and establish its contact friction model. At the same time, the stress and deformation characteristics at the joint of the segment under hydrostatic load are analyzed.
Design/methodology/approach
In this study, the contact and friction in a bolted joint are examined using shear testing. The feasibility of the proposed model is verified by a numerical simulation of tests and a theoretical analysis. Accordingly, the effect of joints on the lining is explored under internal hydrostatic loading.
Findings
The results show that the openings of tunnel segments in joints gradually expand from the positions of the inner and outer edges to the location of the bolt. Moreover, the stress concentration zone is formed at the bolt. Under hydraulic loading, the opening displacement at the joint increases as the water pressure increases; nevertheless, it does not exceed engineering requirements. When the water pressure of the tunnel lining joint reaches 0.5 MPa, the opening of the joint slowly increases. When the water pressure exceeds 0.7 MPa, the opening of the joint rapidly and significantly increases.
Originality/value
Contact and friction in a bolted joint were examined using shear testing. A cohesive zone model of bolted joints was proposed based on test results. The influence of joint behavior on the stability of water conveyance tunnel was studied.
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Dariusz Gawin, Bernhard A. Schrefler and M. Galindo
Presents a fully coupled numerical model to simulate the slow transient phenomena involving heat and mass transfer in deforming partially saturated porous materials. Makes use of…
Abstract
Presents a fully coupled numerical model to simulate the slow transient phenomena involving heat and mass transfer in deforming partially saturated porous materials. Makes use of the modified effective stress concept together with the capillary pressure relationship. Examines phase changes (evaporation‐condensation(, heat transfer through conduction and convection, as well as latent heat transfer. The governing equations in terms of gas pressure, capillary pressure, temperature and displacements are coupled non‐linear differential equations and are discretized by the finite element method in space and by finite differences in the time domain. The model is further validated with respect to a documented experiment on partially saturated soil behaviour, and the effects of two‐phase flow, as compared to the one‐phase flow solution, are analysed. Two other examples involving drying of a concrete wall and thermoelastic consolidation of partially saturated clay demonstrate the importance of proper physical modelling and of appropriate choice of the boundary conditions.
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Shahe Liang, Zhiqiang Zhang and Aiqun Li
A new type of variable damping viscous damper is developed to meet the settings of different damping parameter values at different working stages. Its main principle and design…
Abstract
Purpose
A new type of variable damping viscous damper is developed to meet the settings of different damping parameter values at different working stages. Its main principle and design structure are introduced, and the two-stage and multi-stage controllable damping methods are proposed.
Design/methodology/approach
The theoretical calculation formulas of the damping force of power-law fluid variable damping viscous damper at elongated holes are derived, aiming to provide a theoretical basis for the development and application of variable damping viscous dampers. For the newly developed variable damping viscous damper, the dynamic equations for the seismic reduction system with variable damping viscous dampers under a multi-degree-of-freedom system are established. A feasible calculation and analysis method is proposed to derive the solution process of time history analysis. At the same time, a program is also developed using Matlab. The dynamic full-scale test of a two-stage variable damping viscous damper was conducted, demonstrating that the hysteresis curve is complete and the working condition is stable.
Findings
Through the calculation and analysis of examples, the results show that the seismic reduction effect of high and flexible buildings using the seismic reduction system with variable damping viscous dampers is significant. The program developed is used to analyze the seismic response of a broadcasting tower using a variable damping TMD system under large earthquakes. The results indicate that the installation of variable damping viscous dampers can effectively control the maximum inter-story displacement response of TMD water tanks and can effectively consume seismic energy.
Originality/value
This method can provide a guarantee for the safe and effective operation of TMD in wind and vibration control.
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– The purpose of this paper is to explore a novel breast volume measuring method by mesh projection based on three-dimensional (3D) point cloud data.
Abstract
Purpose
The purpose of this paper is to explore a novel breast volume measuring method by mesh projection based on three-dimensional (3D) point cloud data.
Design/methodology/approach
Mesh projection method, a rapid and accurate method to calculate the volume of models described by triangular meshes, was transplanted to calculate breast volume based on 3D point cloud data derived from a [TC]2 3D scanner. A simple landmarking procedure was developed to decide breast boundary. Breast volumes derived from mesh projection method were compared to the results of water displacement by statistical analysis to validate its accuracy.
Findings
A novel breast volume measurement method is developed based on mesh projection method. By comparison of water displacement, mesh projection method is proved to be accurate to calculate breast volume. Furthermore, a simple and standard breast boundary landmarking procedure is established, which avoids the arbitrariness of the definition of breast boundary and improves the repetition of landmarking.
Practical implications
A simple and convenient tool is provided for bra industries to rapidly and accurately measure breast volume.
Originality/value
Mesh projection method is primarily applied to determine breast volume based on 3D point cloud data. Meanwhile, a simple and standard breast boundary landmarking procedure is put forward.
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