bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding and using the meaning of statements in a bio-ontology: recasting the Gene Ontology in OWL
Authors: Aranguren Mikel Egaña , Bechhofer Sean , Lord Phillip , Sattler Ulrike , Stevens Robert
Published: February 2007

The bio-ontology community falls into two camps: first we have biology domain experts, who actually hold the knowledge we wish to capture in ontologies; second, we have ontology specialists, who hold knowledge about techniques and best practice on ontology development. In the bio-ontology domain, these two camps have often come into conflict, especially where pragmatism comes into conflict with perceived best practice. One of these areas is the insistence of computer scientists on a well-defined semantic basis for the Knowledge Representation language being used. In this article, we will first describe why this community is so insistent. Second, we will illustrate this by examining the semantics of the Web Ontology Language and the semantics placed on the Directed Acyclic Graph as used by the Gene Ontology. Finally we will reconcile the two representations, including the broader Open Biomedical Ontologies format. The ability to exchange between the two representations means that we can capitalise on the features of both languages. Such utility can only arise by the understanding of the semantics of the languages being used. By this illustration of the usefulness of a clear, well-defined language semantics, we wish to promote a wider understanding of the computer science perspective amongst potential users within the biological community.
TGF-β dependent regulation of oxygen radicals during transdifferentiation of activated hepatic stellate cells to myofibroblastoid cells
Authors: Proell Verena , Carmona-Cuenca Irene , Murillo Miguel M , Huber Heidemarie , Fabregat Isabel , Mikulits Wolfgang
Published: February 2007

Background

The activation of hepatic stellate cells (HSCs) plays a pivotal role during liver injury because the resulting myofibroblasts (MFBs) are mainly responsible for connective tissue re-assembly. MFBs represent therefore cellular targets for anti-fibrotic therapy. In this study, we employed activated HSCs, termed M1-4HSCs, whose transdifferentiation to myofibroblastoid cells (named M-HTs) depends on transforming growth factor (TGF)-β. We analyzed the oxidative stress induced by TGF-β and examined cellular defense mechanisms upon transdifferentiation of HSCs to M-HTs.

Results

We found reactive oxygen species (ROS) significantly upregulated in M1-4HSCs within 72 hours of TGF-β administration. In contrast, M-HTs harbored lower intracellular ROS content than M1-4HSCs, despite of elevated NADPH oxidase activity. These observations indicated an upregulation of cellular defense mechanisms in order to protect cells from harmful consequences caused by oxidative stress. In line with this hypothesis, superoxide dismutase activation provided the resistance to augmented radical production in M-HTs, and glutathione rather than catalase was responsible for intracellular hydrogen peroxide removal. Finally, the TGF-β/NADPH oxidase mediated ROS production correlated with the upregulation of AP-1 as well as platelet-derived growth factor receptor subunits, which points to important contributions in establishing antioxidant defense.

Conclusion

The data provide evidence that TGF-β induces NADPH oxidase activity which causes radical production upon the transdifferentiation of activated HSCs to M-HTs. Myofibroblastoid cells are equipped with high levels of superoxide dismutase activity as well as glutathione to counterbalance NADPH oxidase dependent oxidative stress and to avoid cellular damage.
Basal-like phenotype is not associated with patient survival in estrogen-receptor-negative breast cancers
Authors: Jumppanen Mervi , Gruvberger-Saal Sofia , Kauraniemi Päivikki , Tanner Minna , Bendahl Pär-Ola , Lundin Mikael , Krogh Morten , Kataja Pasi , Borg Åke , Fernö Mårten , Isola Jorma
Published: February 2007

Introduction

Basal-phenotype or basal-like breast cancers are characterized by basal epithelium cytokeratin (CK5/14/17) expression, negative estrogen receptor (ER) status and distinct gene expression signature. We studied the clinical and biological features of the basal-phenotype tumors determined by immunohistochemistry (IHC) and cDNA microarrays especially within the ER-negative subgroup.

Methods

IHC was used to evaluate the CK5/14 status of 445 stage II breast cancers. The gene expression signature of the CK5/14 immunopositive tumors was investigated within a subset (100) of the breast tumors (including 50 ER-negative tumors) with a cDNA microarray. Survival for basal-phenotype tumors as determined by CK5/14 IHC and gene expression signature was assessed.

Results

From the 375 analyzable tumor specimens, 48 (13%) were immunohistochemically positive for CK5/14. We found adverse distant disease-free survival for the CK5/14-positive tumors during the first years (3 years hazard ratio (HR) 2.23, 95% confidence interval (CI) 1.17 to 4.24, p = 0.01; 5 years HR 1.80, 95% CI 1.02 to 3.15, p = 0.04) but the significance was lost at the end of the follow-up period (10 years HR 1.43, 95% CI 0.84 to 2.43, p = 0.19). Gene expression profiles of immunohistochemically determined CK5/14-positive tumors within the ER-negative tumor group implicated 1,713 differently expressed genes (p < 0.05). Hierarchical clustering analysis with the top 500 of these genes formed one basal-like and a non-basal-like cluster also within the ER-negative tumor entity. A highly concordant classification could be constructed with a published gene set (Sorlie's intrinsic gene set, concordance 90%). Both gene sets identified a basal-like cluster that included most of the CK5/14-positive tumors, but also immunohistochemically CK5/14-negative tumors. Within the ER-negative tumor entity there was no survival difference between the non-basal and basal-like tumors as identified by immunohistochemical or gene-expression-based classification.

Conclusion

Basal cytokeratin-positive tumors have a biologically distinct gene expression signature from other ER-negative tumors. Even if basal cytokeratin expression predicts early relapse among non-selected tumors, the clinical outcome of basal tumors is similar to non-basal ER-negative tumors. Immunohistochemically basal cytokeratin-positive tumors almost always belong to the basal-like gene expression profile, but this cluster also includes few basal cytokeratin-negative tumors.
Wilson and the Unification of Science
Authors: SEGERSTRALE ULLICA
Published: February 2007

Abstract: This article analyzes the thought and intellectual contribution of Edward O. Wilson, among the most prominent and influential convergenists. It concentrates on the deep ambition going as a bright thread through Wilson's whole scientific output: the unification of science and knowledge. It traces the background of this ambition in Wilson's personal history and follows its various articulations throughout his career.
Converging Technologies in Higher Education
Authors: BALMER ROBERT T.
Published: February 2007

Abstract:  This article discusses the historic relationship between the practical arts (technology) and the mental (liberal) arts, suggesting that Converging Technologies is a new higher education paradigm that integrates the arts, humanities, and sciences with modern technology. It explains that the paradigm really includes all fields in higher education from philosophy to art to music to modern languages and beyond. To implement a transformation of this magnitude, it is necessary to understand the psychology of change in academia. Union College in Schenectady, New York, implemented a Converging Technologies Educational Paradigm in five steps: (1) create a compelling vision, (2) communicate the vision, (3) empower the faculty, (4) create short‐term successes, and (5) institutionalize the results. This case study of Union College demonstrates it is possible to build a pillar of educational excellence based on Converging Technologies.
Signal‐Transducing Proteins for Nanoelectronics
Authors: PICHIERRI FABIO
Published: February 2007

Abstract: This aim of this article is to provide novel paradigms for 21st century nanoelectronics by taking inspiration from the biology of signal transduction events where Nature has solved many complex problems, particularly those concerned with signal integration and amplification.
Building Personal Maps from GPS Data
Authors: LIAO LIN , PATTERSON DONALD J. , FOX DIETER , KAUTZ HENRY
Published: February 2007

Abstract:  In this article we discuss an assisted cognition information technology system that can learn personal maps customized for each user and infer his daily activities and movements from raw GPS data
. The system uses discriminative and generative models for different parts of this task. A discriminative relational Markov network is used to extract significant places and label them; a generative dynamic Bayesian network is used to learn transportation routines, and infer goals and potential user errors at real time. We focus on the basic structures of the models and briefly discuss the inference and learning techniques. Experiments show that our system is able to accurately extract and label places, predict the goals of a person, and recognize situations in which the user makes mistakes, such as taking a wrong bus.
Regret Regulation: Disentangling Self‐Reproach From Learning
Authors: Jeffrey Inman J.
Published: February 2007

This article begins with several testable propositions inspired by Zeelenberg and Pieters (this issue). I argue that a critical skill for decision makers is to decouple the aspect of regret that leads to self‐reproach from that aspect that can be used to learn from the outcome and improve future decision making. Results of an illustrative study are presented and discussed. Two other useful strategies are to match the decision effort to the decision's importance and to break big decisions into smaller ones. I close with a call for research examining regret as a self‐control mechanism.
Subjective Impressions of Minority Group Representation in the Media: A Comparison of Majority and Minority Viewers’ Judgments and Underlying Processes
Authors: Briley Donnel A. , Shrum L.J. , Wyer Robert S.
Published: February 2007

Consumers’ judgments of the frequency with which members of an ethnic minority are represented in advertisements can depend on the processing strategies they employ both at the time the ads are first encountered and at the time the judgments are reported. These strategies, in turn, can depend on whether the consumers personally belong to the minority group in question. European American and African American participants received a series of advertisements that varied in terms of the relative numbers of Black and White models that were portrayed. European Americans overestimated the number of Black models that appeared in the ads when the actual incidence of these models was low, but this overestimation decreased (and thus they became more accurate) as the number of ads containing these models increased. In contrast, African Americans were accurate when only a small number of Black models were presented, but became less accurate as the actual incidence of the models became greater. European Americans apparently based their estimates on the ease of recalling individual instances at the time of judgment, whereas African Americans appeared to perform an online tally of the number of Black models shown at the time they encountered them.
Just Beauty: Ovid and the Argument of Keats's “Ode on a Grecian Urn”
Authors: Bohm Arnd
Published: February 2007

Arnd Bohm is associate professor of English at Carleton University. His Goethe and European Epic is forthcoming. His research includes a study of nomadism and English Romanticism and a continuing investigation into the sources of Goethe's Faust.
Public Preferences and Organized Interests in Health Policy: State Pharmacy Assistance Programs as Innovations
Authors: Gray Virginia , Lowery David , Godwin Erik K.
Published: February 2007

While Congress debated prescription drug coverage for more than a decade before amending the Medicare program in 2003, thirty-one states provided such benefits to their citizens. Why were the same special interests that were reputedly so effective in delaying prescription drug coverage at the national level seemingly incapable of stopping the majority of states from passing the same kinds of legislation? To answer this question, we develop and test a number of hypotheses about the determinants of health policy using Heckman models with data on the adoption, revision, and generosity of state prescription drug programs from 1990 through 2001. We find strong evidence that organized interests had little influence on the adoption of state pharmaceutical assistance programs but can influence their likelihood of revision and the generosity of their benefits. We conclude by discussing the balance of public preferences and organized interests' preferences on state health policy.
The Oxford External Fixator: Fixator Stiffness and the Effects of Bone Pin Loosening
Authors: Churches A E , Tanner K E , Harris J D
Published: February 2007

Simple theoretical deflection analysis and experimental data have been used to assess the stiffness of the Oxford External Fixator for a range of fixator configurations. The loading modes comprised axial compression, bending (in two planes), and torsion. Data are also provided on the effects of clinically loose Schanz bone screws (or pins) on the fixator stiffness. In general:

loosening of one bone pin significantly decreases fixator stiffness; loosening of two pins may decrease the stiffness by 50 per cent or more; loosening of one bone pin causes increased loading on the adjacent tight pin, which may lead to loosening of the second pin; the fixator stiffness is maximized by using the shortest practicable bone pin length and the widest practicable spacing between adjacent pins in the same bone segment; short pins and wide spacing result in the lowest bone/pin interface stresses and minimize the possibility of bone pins loosening.
An Engineering Evaluation of the Oxford External Fixator with Sliding Clamps: Fixator Stiffness and Fracture Healing Assessment
Authors: Churches A E , Tanner K E , Harris J D
Published: February 2007

A theoretical and experimental evaluation of the Mark II Oxford External Fixator with sliding clamps has shown that:

the effective axial stiffness may readily be varied over a wide range;

significant load-bearing may be achieved on the fractured bone while maintaining adequate fracture alignment and stability;

the axial sliding facility is likely to be of greatest benefit in the early stages of fracture healing. Sliding decreases rapidly as fracture stiffness increases and ceases altogether at a relatively early stage in the healing process;

the effects of bone pin loosening are similar to those previously reported for the fixed-clamp Oxford External Fixator;

bone healing assessment using a strain-gauge transducer clamped to the fixator column may become difficult and inaccurate when sliding of the clamps occurs. Temporary locking of the clamps is recommended during the assessment procedure to ensure that sequential tests are strictly comparable.
Fibre Reinforcement of Bone Cement
Authors: Taylor D , Moalic J M , Clarke F M , McCormack B , Sheehan J
Published: February 2007

Polymethylmethacrylate bone cement is used in many orthopaedic applications, including the replacement of hip joints. Fatigue in the cement is a common cause of prosthesis failure, and reinforcement using carbon or other fibres has been attempted as a means of strengthening the material. A new method of reinforcement using a woven preform of carbon or metal fibres is proposed, and shown to confer superior properties in static and fatigue tests. Flexural specimens and compression-loaded models are used in order to infer the behaviour of the actual prosthesis. The initial results reported here are encouraging and prompt more detailed investigation.
Random-Loading and Block-Loading Fatigue Tests on Sharply Notched Mild Steel Specimens
Authors: Marsh K. J. , Mackinnon J. A.
Published: February 2007

Results are given of direct-stress random-loading and block-loading fatigue tests on sharply notched mild steel specimens subjected to a tensile mean stress. It is shown that the random-loading tests are more damaging than the multi-level block tests simulating the same conditions.

Methods of endurance prediction in variable-amplitude conditions are discussed. In random-loading tests the hypothetical S-N curve method gives the better prediction provided that a suitable value of the slope parameter, d, is chosen; this value is not predictable from two-level block tests. The Palmgren-Miner method gave optimistic predictions.

There was little difference between the two prediction methods when applied to the results of the multi-level block tests and the value of d suggested by two-level tests was satisfactory.
Pressure Wave Supercharging of Passenger Car Diesel Engines
Authors: Jenny E , Zamstein B
Published: February 2007

This study is based on experimental test results, typical for small passenger car diesel engines. The influence of engine size on the performance of the car was investigated using four different types of engine. The four types of engine were (a) naturally aspirated engine, (b) engine with turbocharger and waste gate, (c) engine with pressure wave supercharger (PWS) and (d) engine with PWS and intercooler. The performance of the car fitted with the pressure wave supercharger ComprexR* was examined and found to have excellent response, reduced fuel consumption and reduced exhaust emissions.
Aero Engine Development for the Future
Authors: Bennett H W
Published: February 2007

A historical survey of the development and future trends in aero engine design and performance are given. Emphasis is placed on the achievement of low cost of ownership through high fuel efficiency. Simple basic principles controlling the conceptual design and performance are described. The choice of engine thermodynamic cycle is discussed with emphasis on the civil transport engine. The differing requirements of the military aircraft engine are briefly stated. Short-term possibilities for improved performance and longer term speculative proposals are made. Advanced technology requirements in materials, mechanical design and aerodynamics are outlined.
The Differential Compound Engine—A New Integrated Engine Transmission System Concept for Heavy Vehicles
Authors: Wallace F J , Tarabad M , Howard D
Published: February 2007

The paper describes the evolution of the concept of the differential compound engine (DCE) from its original form based on a two stroke diesel engine and a very simple control scheme to its latest form based on a high output four stroke direct injection (DI) diesel engine with an electronically governed fuel pump combined with microprocessor control of variable turbine nozzles and the ultimate possibility of a controlled variable transmission between the turbine and the output shaft.

A detailed description of the control system is followed by a discussion of the steady state performance characteristics showing the very significant advantages of the DCE over existing stepped or continuously variable transmissions coupled to turbocharged diesel engines.
Design and Development Trends in Medium-Speed Diesel Engines to the Year 2000 AD
Authors: Winterbone D E
Published: February 2007

The short-term feature of the medium-speed diesel engine is discussed in relation to fuel availability and changes in operating parameters. It is concluded that although fuel qualities will deteriorate during the next eighteen years there will still be a supply of fuels which are similar to those available today. By the year 2000 AD more fuels may be synthetic ones manufactured from coal, and some might be made from renewable resources. It is concluded that increases in engine power output will be achieved by increases in brake mean effective pressure and not engine speed. Ancillary equipment development will be required to enable the diesel engine to achieve its full potential in this period.
Advanced Computer Aided Engineering and Manufacturing
Authors: Wills K F , Hobbs F S , Greenslade D , Bottomley C
Published: February 2007

The advanced computer aided engineering and manufacturing project (ACE) describes a new, highly advanced system for the efficient production of mechanisms and parts for the aerospace and other industries. It required only moderate investment in machining centres, automated workpiece handling and tool changing and management and control systems. In the case studied it has considerably raised output per operator, turnover of stock and work in progress, greatly cut manufacturing lead time, reduced in-progress scrap and eliminated assembly failures and rejection by customers.
Development of a Conveyorized Coal Feeder
Authors: Gardiner G A , Arthur G F , Wheeler E , Gabbett B R
Published: February 2007

The paper describes the re-design of a coal feeder as used in coal fired power stations. A number of factors such as selling price, revised health and safety requirements, and reduced maintenance and replacement costs were the underlying reasons for the re-design. As a result the man-hours required to produce the unit were reduced by 23 per cent and the selling price by 30 per cent when compared with the unit previously offered by Redler Conveyors Limited. A project team was formed of members from various departments, and this had a major impact on the speed of introduction, just nine months elapsing between idea and completion of the first machine. This enabled the Company to change from being totally uncompetitive to being market leaders.
The Design and Development of a New Range of Large A.C. Motors
Authors: Allsopp M R , Glew C N , Mann T J , Simms M G
Published: February 2007

A small multi-disciplined project group was established to undertake the design and development of a range of medium a.c. motors, including the manufacture of a prototype machine, within a six months period.

This paper describes the development of the range fundamental design principles, manufacturing concepts and the manufacture of four prototype machines. The group were involved, at later stages, in the preparation of the range detail designs, manufacturing data, and commercial information leading to the subsequent introduction of the Unipak range into the market. This also included technical and commercial personnel training sessions.

The activities of the project group are highlighted with respect to the improvements in the specification and cost effectiveness of the product range, that were the direct results of detailed market surveys, fundamental design improvements and the emphasis on design for manufacture of the machine components.

The success of the Unipak development project is expressed in terms of the increased competitiveness of the Unipak range, improved manufacturing processes, increased specification and how this has affected other areas and aspects of the company's business.
Developing Industrial Managers in the 1980s
Authors: Swann K
Published: February 2007

Outlines the historical background to the performance of UK industry from which the weaknesses in management education are identified, followed by an indication of needs for the 1980s.
An Investigation into Distribution Parameters of Steam Turbine Blade and Wheel Vibration Measurements
Authors: Farid M U
Published: February 2007

This investigation was carried out to find a concise and meaningful way of describing the steam turbine blade and wheel vibration measurements which would enable predictions from ‘experimental’ to ‘production’ wheels to be made with known level of confidence. A large volume of vibration measurements from many years of testing was available. For the purpose of this study it was decided to concentrate the analysis on stage six of low-pressure turbine wheels. Two types of wheels, similar in every respect except root fixation, were used.

The method of obtaining and interpreting static and dynamic blade and wheel vibration frequency measurements is described. Measurements from the wheels selected for study were analysed by appropriate statistical techniques to test assumptions and hypotheses derived from long-standing experience of empirical vibration tests.

It was found that statistical analysis yields results in line with engineering expectations. In specific instances relating to the use of ‘experimental’ wheels in predicting the performance of ‘production’ wheels the statistical analysis not only confirmed existing practice, but pointed towards a more precise foundation of the procedure of estimating dynamic frequencies for production wheels.

The suitability of the use of statistical techniques for analysis of problems of this kind is discussed.
Investigation of Air Driven Ejectors at Elevated Temperatures
Authors: Owen I
Published: February 2007

Ejectors are often used to pump difficult fluids where conventional pumps will suffer operational and maintenance problems. One such application where ejectors may be used is in the pumping of high temperature gases. Experiments show that increasing the induced gas temperature causes a reduction in the ejector pumping performance in terms of its entrainment rate. A one-dimensional compressible flow theory is presented which predicts this, and the effects of other parametric changes and which also shows that the pumping performance can be restored by increasing the temperature of the forcing gas.
An Easy to Measure Average Peak/Valley Parameter for Surface Finish
Authors: Whitehouse D J
Published: February 2007

A peak to valley parameter is devised which makes use of crossing theory. The principal use of the parameter is to provide a check on existing parameters.
The Sources of Damping in Rolling Element Bearings under Oscillating Conditions
Authors: Walford T L H , Stone B J
Published: February 2007

An analysis is presented of the stiffness and damping which may be expected from a rolling element under oscillating conditions. The level of damping, which may be expected from a complete bearing plus the necessary joints, is then examined. It is shown that the assumption of no damping in the joints yields theoretical levels of damping which are substantially less than the levels measured experimentally. It is concluded that the joints are the major source of damping.
Response of a Gyropendulum Subject to Parametric Excitation
Authors: Krishnan V
Published: February 2007

This paper concerns the response of a gyropendulum subject to vertical harmonic excitation. Instability of the Mathieu type is shown to occur, the principal region of instability lying about the nutational frequency of the system. Experimental results are presented which clearly indicate the validity of the theoretical prediction. It is also shown that an unstable gyroscopic system can be stabilized by vibrating the equipment with the proper choice of vibration parameters. In such cases, the additional stabilizing factor has been analytically derived. Based on the above analysis, practical suggestions for instrument design are also provided.
Controlling the Dynamic Characteristics of a Hydrostatic Bearing by Using a Pocket-Connected Accumulator
Authors: Goodwin M J , Hooke C J , Penny J E T
Published: February 2007

This paper describes a theoretical and experimental investigation of the dynamic characteristics of a capillary-compensated oil-lubricated hydrostatic bearing which has an accumulator connected to the bearing pocket via a second capillary restrictor. Results show that by careful selection of accumulator and restrictor the bearing can be tuned to give an optimum system performance. Such a facility can be of considerable use if the hydrostatic bearing is being used to support other machinery, for example in the support of journal bearings used with flexible rotors. By tuning the hydrostatic bearing dynamic characteristics, optimum rotor support impedance might be achieved thereby giving the engineer some control over system resonances and stability.
Blockage Corrections for Rectangular Flat Plates Mounted in an Open Jet Wind Tunnel
Authors: Sayers A T , Ball D R
Published: February 2007

The correction that must be applied to the upstream wind velocity, when a rectangular flat plate normal to the flow direction is placed in an open jet wind tunnel, is determined and is found to be at all times equal to or greater than unity. It is also found to be dependent upon the distance of the body from the tunnel outlet, and the projected area of the body. Comparisons with previous work carried out in closed wind tunnels are made to confirm the experimental technique used.
On the Inherent Compensation in an Air Journal Bearing
Authors: Grewal S S
Published: February 2007

Some experimental results are presented on the influence of inherent compensation in an externally pressurized, orifice-compensated air journal bearing.
Assessment of Flash Vessel Design
Authors: Bryant D
Published: February 2007

This paper proposes a method of assessing the size and rating of vertical and horizontal steam flash vessels for a range of pressures up to 25 bar using droplet separation theory.
Axisymmetric Outflow from Large Vessels
Authors: Kubie J
Published: February 2007

A model of axisymmetric liquid outflow from large vessels is developed and is used to explain aspects of flow for self-venting and choked outlets. It is shown that for flows with self-venting outlets the model relates the liquid level to the flow. It is also shown that for flow with choked outlets the model gives a conservative estimate for the minimum liquid level required to prevent drawdown of the supernatant phase. The results obtained are also compared with the experimental and theoretical work of previous investigators.
The 250 kW and 3 MW Wind Turbines on Burgar Hill, Orkney
Authors: Lindley D
Published: February 2007

The Wind Energy Group has designed and manufactured a 20 m diameter wind turbine generator, rated at 250 kW. Following an extensive period of tests, it was erected on Orkney in July 1983. It rotated for the first time in late July and was synchronized with the grid in August 1983. The commissioning tests have been completed and are to be followed by not less than twelve months of performance monitoring. This paper gives details of the machine design and specification, details of sensors and monitoring system and early results of the commissioning phase.

As part of the same programme, a 60 m diameter turbine rated at 3 MW has been designed for installation in 1985 at the same location. Details are given in this paper of the design and specification of this machine.
The Power Game—the Development of Conventional Power Stations 1948–1983
Authors: Sherry A
Published: February 2007

The paper traces the development of conventional power stations and associated systems of the Central Electricity Generating Board (CEGB) over a thirty-five year period. During that time turnover increased by a factor of over thirty, unit capacity by a factor of twenty, whilst the installed capacity increased almost fivefold. Early difficulties with large high-pressure units are described and the measures taken to overcome them, leading to current high levels of performance. To support these developments, the CEGB has built up a powerful engineering and scientific capability and has accumulated a wealth of experience in the solution of power station problems. Operation and maintenance techniques have been developed to a high degree. The paper also outlines the changes in the organization of electricity generation in the UK which have occurred in response to changing circumstances.
Stratified Flow of Liquids in Steeply Sloping Pipes
Authors: Taylor B J
Published: February 2007

A method is presented for calculating the velocity and depth of a liquid which is accelerating towards its terminal velocity in a steeply sloping circular pipe.
Developments in the Handling and Sorting of Parcels and Packets
Authors: Goodison H
Published: February 2007

The paper reviews developments in the British Post Office in the handling and sorting of parcels and packets since 1883 which was the first year of the Post Office parcel service. Recent developments that are described are: high speed parcel and packet sorting machines; voice recognition; high speed container uplift systems; Safeglide chutes and automatic recording and control of bags and containers. The components and parameters of the parcel sorting office of the future are described.
Optimizing the Financial Advantage of Using Cnc Machine Tools by Use of an Integrated Suite of Programs
Authors: Primrose P L , Leonard R
Published: February 2007

By evaluating the parameters relating to machine tool investment, with the aid of an integrated suite of programs based on discounted cashflow principles, it is shown that CNC machines are viable over a much wider range of applications than was previously considered. The program, as described in a companion paper (1), has been used to assess the effect of each parameter in the financial appraisal, with the corresponding results being discussed. The paper then goes on to describe how this technique can be readily used by a company to evaluate a range of possible options, thus enabling the optimum investment decisions to be made. Finally, it is shown that because previous authors used an incorrect methodology to evaluate returns, this resulted in an understatement of the financial benefits of CNC.
Health and Safety Legislation and Engineers
Authors: Cartwright P A , Wearne S H
Published: February 2007

Through legislation and other social forces the UK and other industrial societies appear to be expecting increasingly higher standards of health and safety to result from engineers' work. Engineers therefore need to know the controls of hazards required by law. They also have to consider their professional duty to anticipate new hazards.

This paper gives the results of questioning small samples of UK engineers to assess their problems and needs under health and safety legislation. It includes a specification for engineering education and a description of the teaching in one undergraduate degree.
Financing Major Export Contracts
Authors: Brown A J
Published: February 2007

An examination of the effects different methods of financing export contracts have on payment terms, cash flow, price escalation and payment guarantee problems.
Variations
Authors: Meakins E J , McCabe T I
Published: February 2007

This paper sets out the reasons why variations to an original contract between supplier and purchaser sometimes occur and the best way to handle them from both the supplier's and the purchaser's viewpoints. The pitfalls are pointed and two examples of negotiations for variations are given.
Computer Controlled Pneumatic Servo Drives
Authors: Weston R H , Moore P R , Thatcher T W , Morgan G
Published: February 2007

This paper describes how microprocessor-based controls can be used to produce low cost pneumatic servo drives which could find wide application in manufacturing industries. The approach incorporates digital compensation for system non-linearities so that, when positioning loads in a ‘point to point’ mode, it is possible to achieve a significant improvement in both the static and dynamic performance of the drive.

For the compensation algorithms implemented a theoretical foundation is presented based on a linearized model of pneumatic drives. The paper also describes how microprocessor-based hardware and software have been constructed to evaluate performance criteria. This test facility has allowed the software implementation of the compensation algorithms to be refined so that satisfactory performance can be achieved with both translational and rotational drives utilizing various forms of transmission. The test facility has also allowed various control system elements to be evaluated so that pneumatic drives suitable for industrial application, can be specified.
Oscillatory Instabilities Generated in a Double-Pin and Disc Undamped System: A Mechanism of Disc-cbrake Squeal
Authors: Earles S W E , Badi M N M
Published: February 2007

A dynamic analysis is presented of a double-pin and disc system, which is undamped and has linear characteristics. A self-induced oscillatory motion is generated which can become unstable for certain combinations of the system's parameters. Unstable motion requires a set of inequality equations to be satisfied, and a necessary, but not sufficient condition is that one or both of the pins shall have a negative (digging-in) angle of orientation to the disc surface within the range 0 < θ < tan−1 μ. Sufficient conditions for unstable motion are dependent on the magnitudes of the system parameters and may be obtained by giving unequal values to corresponding parameters on the two-pin systems.

Distinct changes from a ‘quiet’ to a ‘noisy’ state are observed on an experimental system; the ‘noisy’ state regions having a good correlation with the instability regions shown theoretically.

It is concluded that a ‘kinematic constraint’ or ‘geometrically induced’ class of instability exists theoretically which essentially describes the mechanism of squeal noise generation in disc-brakes.
The Collapse of a Gas Bubble near a Solid Wall by a Shock Wave and the Induced Impulsive Pressure
Authors: Shima A , Tomita Y. , Takahashi K
Published: February 2007

An experimental study concerning the shock wave—bubble interaction was conducted in order to obtain a unified consideration of the mechanism of the impulsive pressure generation induced by the cavitation bubble collapse. It was found that the relation between the maximum impulsive pressure, pG, max, and the relative distance, lc/Re, is closely similar to the known result obtained from a single spark-generated bubble, and that a gas bubble within the region of lc/Re ≤ 7 behaves as a source capable of generating more intensive impulsive pressure than the impact pressure induced by a shock wave impinging directly on a solid wall without the presence of a gas bubble.
Estimation of Linearized Oil-Film Parameters from the Out-of-Balance Response
Authors: Sahinkaya M N , Burrows C R
Published: February 2007

This paper outlines a simple approach to the identification of linearized oil-film characteristics from the rotor's synchronous response. The method is shown to be effective in filtering signal noise.
Review of Keyway Design Considerations
Authors: Polak P
Published: February 2007

Design of keyways with a view to avoiding fatigue failure is discussed in terms of pictorial stress flow, common loading cycles and comparisons of published data on stress concentration. A method for predicting the stress concentration factors in round-ended (end-milled) ISO-shaped keyways is put forward, including the effect of key length.
Externally-Pressurized Gas-Lubricated Floating-Ring Porous Journal Bearings: Part 1: Steady State Analysis
Authors: Malik M
Published: February 2007

A new type of gas-lubricated floating-ring journal bearing in which the fixed bearing and the ring are both porous, has been conceived and analysed, theoretically, for the steady state characteristics. Bearing characteristics are presented against two design parameters, namely, clearances ratio and permeability parameter. The comparison of these characteristics with those of externally-pressurized plain porous journal bearings shows that the new bearing represents, with its steady state performance, a distinctly advanced bearing design.
Challenge, Change and Commitment
Authors: Waller J A
Published: February 2007

The author illustrates the challenges which he has faced in many changes of function and responsibilities. In doing so, he relates them in a way which highlights many fundamental operating and engineering truths. He hopes they will be recognized by younger Engineers making their way in engineering, and adopted by them as part of their engineering education.

Finally he lends support to the President's initiative to the Institution and its members to play a leading part in the turn round of the engineering industry. To this end he challenges Automobile Division members to commit themselves to the Institution and to adopt a theme for personal action during his year in office: ‘Resolve your Problems’
Making for Export
Authors: Souch D J W
Published: February 2007

Reviews the development of electric traction in the railway industry with reference to some export achievements of U K companies. Outlines improvements in equipment, testing methods, and design, and comments on electrification.
A French Perspective on the Cost Effective Maintenance of Passenger Coaching Stock
Authors: Ravenhall E N
Published: February 2007

In October 1981 the author travelled to France where, as a guest of SNCF, he visited various French railway headquarters departments, Hellemmes Main Workshops and Massena Depot both to probe the philosophy behind passenger coaching stock maintenance on that side of the Channel and observe its current, practical application. This paper briefly outlines the organization and methods which are being employed by SNCF to improve the cost effectiveness of their approach to this common concern, and seeks to highlight areas where fresh insights may be introduced to benefit the maintenance of coaching stock on Britain's railway system.
The German Federal Railway Class 120 Three-Phase Drive System: Service Trials
Authors: Guldenpenning A U W
Published: February 2007

Since 1980, the German Federal Railway (DB) has been conducting service trials with five prototype Class 120 locomotives, during the course of which studies have been made of the locomotive as a whole, of the availability and reliability of individual components and of compliance with the conditions set out in the specification. These trials have shown that the basic concept and the system engineering used in this locomotive have come fully up to expectation. Such reactions on the overhead line equipment (OHLE) as have been identified have fallen well within the limits laid down. The scope for feeding power back into the OHLE will depend very much on the programme to which the locomotive is working, but is expected to be on the scale originally envisaged. The regenerative brake has proved itself as a highly reliable piece of equipment. I n terms of ride, the Class 120 has been passed for 200 km/h running. As an addendum to the specification, refinements have been made to the design of the Class 120, in order to make it a truly mixed traffic locomotive. Refinements and modifications were necessary in the power and control systems, as well as in certain components, which had to be improved in order to give better availability.
London Transport'S 1983 Tube Stock
Authors: Ware D K
Published: February 2007

The 1983 tube stock has been designed for use on the Jubilee Line and should enter service there in the Spring of 1984. The line itself has suffered many changes—in both direction and identity, metamorphosing from the original Fleet Line concept of 1971 through the River Line to the full Jubilee Line proposal of 1977. It has now been truncated to its Stage 1 terminus of Charing Cross and the intention to continue to Woolwich has been abandoned.

The design of the rolling stock could hardly avoid changes of a comparable nature and the paper describes some of these. The trains have finally emerged as fairly conventional vehicles based on the Piccadilly Line 1973 tube stock. Many changes both major and minor have however been incorporated and the design may well be the final and most developed version of the classic London tube car with steel underframe.
The Dissipation of Frictional Energy from the Interface of an Annular Disc Brake
Authors: Day A J , Newcomb T P
Published: February 2007

The performance of resin bonded composite friction materials in a particular brake design is strongly dependent upon the dissipation of frictional heat from the interface. This energy transformation has been studied using finite element techniques for a simulation of the braking friction process in an annular disc brake, which combines both brake performance and brake temperature analysis and avoids many of the assumptions necessary in conventional analyses.

Negligible amounts of energy interchange, compared with the total kinetic energy dissipated, arise from chemical reactions within the friction material, but the formation of surface layers and interfacial wear products do have a significant effect upon heat transfer from the interface. Calculated temperature distributions over individual brake applications indicate that interface contact resistance leads to different temperatures at the surfaces of disc and lining so that heat partition between the two mating bodies cannot realistically be assumed constant under braking conditions.

The distribution of frictional heat generation over the interface is dependent upon interface pressure distribution and is therefore also affected by material wear and thermal expansion. These effects are incorporated in the analysis, and calculated temperature, interface contact and pressure, and wear distributions are compared with observed and measured experimental results from an annular brake rig.
Rotary Mechanical Seals in Process Duties: An Assessment of the State of the Art
Authors: Nau B S
Published: February 2007

The operating conditions, performance, existing and desirable standards for rotary mechanical seals are discussed. Research needs are reviewed and the need for functional rather than dimensional standards is emphasized.
Operational Performance of Waste-to-Energy Plants
Authors: Barnes N
Published: February 2007

The recovery of heat from the mass incineration of solid waste can make a useful contribution to the nation's energy needs. Whilst we have been slow to exploit fully this resource in Great Britain, there are some notable plants both here and abroad which have demonstrated commercial success over a number of years. When operated with engineering judgement they are reliable and dispose of waste economically in urban areas.
Blade Configuration Optimization and Performance Characteristics of a Simple Savonius Rotor
Authors: Sayers A T
Published: February 2007

The generation of low cost power in rural areas of the third world can be aided by using 44 gallon (210 litre) oil drums cut longitudinally in half and each half mounted on a vertical rotating shaft in the form of a Savonius rotor. This paper describes wind tunnel tests carried out on a model of such a rotor to determine the positioning of the two blades for maximum power output. For the optimum blade configuration the power and performance coefficients are determined and comparisons with the results of previous work are made. The results show that for maximum power output blade overlap is required along with negative blade separation, a finding which has not previously been reported.