bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review: Burning Refuse-Derived Fuel in a Rotary Cement Kiln
Authors: Lockwood F C , Ou J J 
Published: February 2007

In cement kilns, combustion takes place under very high flame temperatures and relatively long residence times. These conditions are favourable for the burning of refuse waste. The purpose of this note is to review the combustion and pollutant emission implications of using such a fuel as a supplementary source of heat in a cement kiln. Based on technical and environmental considerations, the analysis of burning refuse-derived fuel (RDF) in a cement kiln shows that no special firing technology has to be installed except that of the RDF handling system, that there is an upper limit to the total fuel consumption (no more than 30 per cent) for firing RDF and that there is no increase in the emission levels of air pollutants (including acid gases, dioxins, furans, etc.). At present, there seems to be no economical advantage in burning RDF. However, if municipal solid waste (MSW) is generated in large amounts and financial support is provided by the local authority to cover the investment/operating costs, burning RDF in cement kilns will become economically attractive as well as feasible.
Laminate Tooling for Injection Moulding
Authors: Glozer G R , Brevick J R 
Published: February 2007

The main goal of this research was to develop a method of prototyping injection moulded parts which produces a representation of the production part, including not only the part shape and functionality but the process as well. A prototyping method that meets all of these requirements could greatly aid in reducing the time required to bring a new product to the market by using the information gained from this prototype to manufacture a production tool that will be right the first time. Tooling constructed of laminations is appealing for prototyping or production because of the flexibility it affords in terms of rapidly altering mould geometry, gating or cooling passage design. This report summarizes a ‘proof of concept’ project which took a selected part geometry through the entire laminate tool manufacturing process. This report is divided into five sections: (1) introduction to the prototyping process, (2) background of current prototyping processes and description of the laminate tooling method, (3) description of the geometry selected for this work and the manufacturing details, (4) evaluation of the performance of the laminate injection mould and (5) conclusions.
The Integration of Coordinate Measuring Machines within a Design and Manufacturing Environment
Authors: Medland A J , Mullineux G , Butler C , Jones B E 
Published: February 2007

The role of the coordinate measuring machine within the inspection process has changed throughout its brief development. With its integration with industrial computer aided design (CAD) systems, its role is to change yet again. This paper presents the difficulties and limitations of current practice and identifies the inputs and decisions that need to be made within an integrated manufacturing environment. A research programme was undertaken to investigate an approach based upon intelligent communications between systems. This led to the creation of a demonstration system that was employed in the measurement of industrial components. A case study, using a standard test block, is included to illustrate the processes undertaken. This includes feature identification, probe calibration and selection strategies and automatic re-routing to minimize changes in probes and orientations. It is proposed that the approach demonstrated can be incorporated within a concurrent engineering environment to provide feedback and information about machine adjustments through a constraint modelling process.
The Make or Buy Decision in the Context of Manufacturing Strategy Development
Authors: Probert D R , Jones S W , Gregory M J 
Published: February 2007

This paper describes an approach to structuring the make or buy decision process, basing it firmly in the context of an overall manufacturing strategy. The work has been carried out jointly by the University of Cambridge Manufacturing Engineering Group and Lucas Industries. A review of the current state of ideas surrounding the linked issues of vertical integration and make or buy decisions is presented. Important features of the approach include identification of core manufacturing capabilities, assessment of the role of technology in manufacturing, the development of a cost model to support make or buy decisions and a review of the strategic implications of varying degrees of vertical integration. Further, the approach has been embodied in a practical methodology that has been applied within Lucas Aerospace. A brief review of this practical application is included.
Layout Design of Large Made-To-Order Products Using a Knowledge-Based System
Authors: Hills W , Barlow M , Cleland G 
Published: February 2007

Work is described which is concerned with the application of knowledge-based and emergent-order programming techniques to conceptual layout problems in the field of large made-to-order products. The aim of this work has been to develop a prototype for computer aided design (CAD) tools that manipulate and analyse a product's topology, rather than its precise geometry. Features of the system include: working prototypes of a generic layout-oriented product model database schema and a layout design process. A knowledge-based system is used to advise the designer on optimal layout strategies and then, after layouts have been generated, to provide advice and assistance in the selection of the final layout.
Machine Vision Analysis of Welding Region and its Application to Seam Tracking in Arc Welding
Authors: Li Y , Middle J E 
Published: February 2007

Unlike the application of machine vision in many other fields, there is a particular problem in developing machine vision for automated and robotic welding processes, because the disturbance of the arc light deteriorates the field to be viewed. This paper describes an analysis of the radiated energy from the weld pool, and based on this describes how vision sensing of the welding region may be improved. An approach using specified pattern parameters is described to evaluate the ability to recognize an acquired image under different conditions such as with vidicons or sensor devices, different welding variables and optical parameters. Based on analysis of radiation from the welding region, a satisfactory wavelength range for sensing the image of the weld region is proposed and proved by experimentation. Images of gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) regions have been modelled and successfully implemented for seam tracking control with a simultaneously developed low-cost vision system.
New Turbo Trains for the Chiltern Lines
Authors: Paling K D 
Published: February 2007

The paper describes the evolution of the new Class 165 Network Turbo Diesel Multiple Units for the Chiltern Lines of Network SouthEast, from initial business requirement to emerging service experience. Development of the Turbo concept and Business Specification, including the extensive use of mock-ups and models, is described in detail. Translation of the Business Specification into a technical Procurement Specification and the procedures followed for the procurement of Turbos are explained. The manufacture, testing, commissioning, and emerging service experience of Turbos are described. Reference is made to the further introduction of Turbos to Network SouthEast's Thames and West of England lines and a view is given of possible future developments.
Mechanical Damage to Aircraft Structures from Lightning Strikes
Authors: Reid G W 
Published: February 2007

The various types of current waveforms associated with lightning discharges are discussed together with their relevance to different areas of the aircraft structures. The physical damage that could be sustained by aircraft material due to lightning strikes, in particular the damage to composite material especially carbon fibre, is described. This damage is primarily due to the very fast heating and impulsive forces which lightning currents can produce. Minimum cross-sectional areas required to carry these currents safely are discussed as well as the effect of moisture content and loading the samples during test for the case of carbon fibre composite material. Details of the effects of arc attachment to various composite materials and also metal with the degree and type of damage that can be produced are reviewed.
Aero Engine Ceramics—the Vision, the Reality and the Progress
Authors: Angus J P 
Published: February 2007

Figure 1 shows ceramic exhaust nozzle petals and their application on a military engine. The ceramic material used is one of the most advanced materials in the world today. It consists of two-dimensional woven and laminated silicon carbide fibres in a chemical vapour infiltrated silicon carbide matrix. In this application this material will eventually be expected to perform at 1200°C, 300°C hotter than today's cooled metal petals and last four times longer. To date the petals have been successfully interchanged with the existing metal petals, which run in a cooled environment on this engine. The Rolls–Royce target is to develop ceramics which operate up to 1400°C, which is 500°C hotter. Before ceramic nozzle petals can enter service there are many difficult issues that must be addressed. One of these is the present long and very costly production route. This application illustrates the reality of applying ceramics to aero engines. It is one of the easier applications! Why is it worth persevering with this difficult technology? The industry is a very competitive one. Ceramic materials offer the potential for significant performance improvements. They may in time create the competitive edge which means the difference between a growing or shrinking market share.
Ligament Forces at the Knee during Isometric Quadriceps Contractions
Authors: Zavatsky A B , O'Connor J J 
Published: February 2007

A mathematical model of the knee in the sagittal plane was used to investigate the ligament forces resulting when a posteriorly directed external force, applied to the tibia, resists extension of the knee under increasing isometric quadriceps contractions. The model is based on simple geometric representations of the bones, ligaments and muscles at the knee. An elementary mechanical analysis was used to predict which ligament, the anterior or posterior cruciate, was loaded at a given flexion angle and known line of action of the external force. Ligament force, as a proportion of the external force, was calculated first assuming the ligaments to be represented by single, inextensible lines. Modelling the ligaments as continuous arrays of extensible fibres then showed that tibio-femoral translations and ligament forces increased non-linearly with increasing muscle forces and approached asymptotic values which depended on flexion angle. In most positions of the joint, the calculated asymptotic ligament force values were less than the reported ultimate strength of human ligament, despite quadriceps forces of over three times body weight. The possibility of these asymptotic values of ligament force may explain why, at certain flexion angles, large forces can be developed by the muscles at the knee without ligament rupture.
Recommendations with Respect to the Improvement of Lubricating Qualities of Synovial Fluid in Artificial Joints
Authors: Gavrjushenko N S 
Published: February 2007

This paper gives a short description of the lubricating properties of yellow and red bone marrow taken from a femur of a cadaver. The experiments have been conducted on a ‘ball-on-plate’ model. The balls were made from steel 100 CR6 (German) and the plates were made from the same steel and ultra-high molecular weight polyethylene (UHMWPE, German ‘Herulen’). The friction coefficients under loads of 50 and 300 N were determined with different combinations of friction components. It has been found that the lubricating properties of yellow and red marrow have advantages over synovial fluid. In the light of these results the author develops a new approach to the design of a new hip endoprosthesis.
An Isoelastic Prosthesis Using a New Composite Material
Authors: Taylor D , Martin C , Cornelis B , Jones M E B 
Published: February 2007

A new particulate composite material has been assessed with regard to the design of an ‘isoelastic’ or ‘modulus matched’ hip prosthesis. Three different prototype designs were assessed, each of which consisted of a femoral component made from the composite material, attached to a metal ball via a metal ‘spike’ insert. The prototypes varied in terms of the detailed shape of the spike, which was modified in the light of photoelastic stress analysis, so as to produce a more acceptable stress distribution to the composite material in the proximal region. Prototypes were made by hand moulding and by transfer moulding; both methods produced defects of various kinds. Simulation tests were conducted using a model of the proximal femur constructed from glass fibre composite, cyclically loaded in a servo-hydraulic testing machine. Though some difficulties were experienced with defective mouldings, especially for the transfer moulding process, a clear improvement was demonstrated for the final (Mark III) design. The fatigue endurance of this prototype was similar to that of conventional metal prostheses tested under similar conditions. Fatigue crack propagation tests were carried out on samples of the composite material to establish its propagation threshold. These results were combined with a finite element stress analysis and fracture mechanics theory to estimate the critical crack length for fatigue in this prosthesis. It was thus possible to specify the maximum safe size of defect that could be tolerated in use.
Modelling and Simulation of Thermal and Closed-Loop Control Behaviour of Uranium-Bed Assemblies
Authors: Konstantellos A , Karditsas P J 
Published: February 2007

A theoretical model describes the thermal and closed-loop control behaviour of uranium-bed assemblies used for the storage of hydrogen or its isotopes. Storage is in the form of UH3 at ambient temperature, and heating uranium-beds to 700-900 K can deliver the desorbed gas at pressures useful for transport to other process equipment. Modern compact uranium-bed assemblies include multiple-containment stainless-steel vessels to provide vacuum insulation and safety boundaries and to accommodate the heating and cooling systems. The thermal model describes the heat balance and the time evolution of the hydride powder temperature and includes radiation, dissociation and convection heat-transfer processes. The process controller simulation includes PID-type control/decision and adaptive algorithms. The model allows for simulations of the behaviour of the closed-loop system to demonstrate its effectiveness and to achieve controlled release of hydrogen, deuterium and tritium gas. A numerical example is presented which is based on a typical bed assembly. The simulation methodology used can easily incorporate more complex geometries, additional process components such as control valves, pumps and reservoirs as well as advanced control strategies as a means of predicting gas flow/pressure characteristics and bed safety. This study was initiated after the first applications of uranium and other metal hydride beds in the active gas handling plant (AGH) of the Joint European Torus Project (JET), where (a) an in-depth knowledge of the bed control system and operation under tritium gas and a prediction of system parameters and tritium gas behaviour were needed, and (b) minimization of unnecessary testing and stressing of the uranium beds was required. The model can, in general, be applied to any hydride gas storage system and also has the capability to simulate the hydriding process.
Theoretical Predictions of the Full-and Part-Load Performance of an Air-Blown Fluidized Bed Gasification Combined Cycle
Authors: Davison J E , Soothill C D 
Published: February 2007

It is important that any future power generation process should have a high thermal efficiency, be able to operate over a wide range of conditions and have low environmental emissions. This paper presents the results of work carried out by the British Coal Research Establishment (CRE) and European Gas Turbines (EGT) to evaluate the overall performance of an air-blown fluidized bed coal gasification combined cycle (topping cycle). This evaluation formed part of a major appraisal of the topping cycle chaired by EGT and which was carried out for the Department of Trade and Industry (DTI). Performance predictions for commercial plants based on topping cycle technology were produced using a computer flowsheet modelling package developed at the CRE. The predicted full-load thermal efficiency of a base case plant using commercially available gas and steam turbines was 46.9 per cent. An evaluation of different options for providing the input air to the gasifier and the effects of likely future emission limits were also evaluated. The part-loaded performance of the base case plant was predicted and it was shown to be capable of operating efficiently at power outputs down to 35 per cent or less. This flexibility means that the process should be suitable not only for base-load operation but also for locations where part-load operation may be required.
A Study of Vision-Based Measurement of Weld Joint Shape Incorporating the Neural Network
Authors: Bae K-Y , Na S-J 
Published: February 2007

Visual sensing of the surface geometry is often necessary to inspect and evaluate the quality of welded joints as well as to sense the transient distortion of a structure during welding for the feedback of its current geometry. This investigation presents a simple and non-contact digitization method of the vision-based system for measuring the three-dimensional surface geometry of the object distorted by welding. Its basic principles are based on the equation derived from the geometric optics, for which the illumination of the laser beam was controlled in the form of the projected plane. This method utilized a 10 mW He-Ne laser for the structured light and a charge coupled device (CCD) camera as the vision sensor. When the laser stripe is projected on to the weldment, a minute deviation from the perfect plane existing on the specimen surface causes a distortion of the stripe. The shape and amount of the weldment distortion can be then calculated by analysing the distorted laser stripe. In this study, a neural network was proposed and implemented for recognizing the laser stripe features from the image plane. A calibration scheme of corresponding an image to the world position was also adopted for determining the sectional features of the welding distortion. The feasibility of determining the welding distortion by the proposed vision-based system was demonstrated through the experiments with various types of specimen.
The Detection of Short Time-Scale Tool Degradation Events during Face Milling Operations Using Cutting Force and Acoustic Emission
Authors: Wilcox S J , Reuben R L 
Published: February 2007

Experimental data are presented on the effects of short time-scale events on measured cutting force and acoustic emission during face milling. The events of interest are those that occur within a few revolutions of the cutting tool and are associated with non-continuous degradation such as insert edge chipping. A processing scheme is suggested whereby the events are recognized and distinguished from each other using a neural network simulation applied to the peaks of the r.m.s. acoustic emission records. It is found that acoustic emission is a more suitable description of such events than is cutting force. Finally, a record of the network simulation acting as a breakage detector in real time on a computer numerical control (CNC) milling machine is presented.
Solution of the Classic Thermal Regenerator Problem
Authors: Organ A J 
Published: February 2007

An exact, general and algebraically simple solution is obtained to the classic model of the thermal regenerator—general in the sense of covering flushing ratios, A, of any magnitude, including the small values of interest in the context of Stirling cycle machines, and of depicting start-up and cyclic steady state operation. Specimen solutions turn the conventional picture of regenerator performance on its head: for a flushing ratio equal to or less than unity, for example, zero heat-transfer coefficient (NTU = 0) leads to a temperature recovery ratio of 100 per cent! At a thermal capacity ratio, NTCR, above a certain, minimal, value, the wall temperature distribution sits invariant between the extremes of gas temperature swing, and increased NTCR has no effect on temperature recovery ratio. The findings are sufficient to explain reports of unexpectedly good performance of Stirling machines with regenerators of cotton wool or glass fibre.
Combustion in High-Speed Direct Injection Diesel Engines—A Comprehensive Study
Authors: Winterbone D E , Yates D A , Clough E , Rao K K , Gomes P , Sun J-H 
Published: February 2007

This paper reports the latest results of a comprehensive project investigating the performance of a Ricardo Hydra direct injection diesel engine. Early work covered a number of aspects of research into the gross behaviour of this engine: this paper concentrates on techniques for obtaining quantitative data from photographs of the combustion process. High-speed photographs, at framing rates up to 20 000 frames/s, were taken using a piston with a quartz bowl, at engine speeds up to 3000 r/min. The pre-combustion period was illuminated using a synchronized copper vapour laser. After the initiation of combustion, the process is self-illuminating and information on the combustion process was obtained by analysing the radiation emitted by the carbon particles. The two-colour method was used to evaluate the temperature of the combustion gases over the full field of view. The images have also been analysed by a cross-correlation technique to obtain velocity information. Tests have been performed on the engine over a wide range of operating conditions, but this paper concentrates on the effect of swirl ratio on combustion. It will be shown that too much swirl increases the ignition delay period and results in an increase in the NOx emissions but a decrease in the soot. It will also be shown that the velocity pattern after combustion is in good agreement with that evaluated by Arcoumanis et al. at the end of compression, which implies that swirl persists through the combustion period despite significant decay.