bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Environmental Requirements—A Basis for Developing Products in the Heating and Ventilating Industries
Authors: Ryd Harriet 
Published: October 2007

The accelerating rate of energy consumption and increasing environmental damage appear at present to be two unavoidable consequences of measures taken in the course of development planning. One of the explanations for this is that the essential climatic function of a building development—that of modifying the natural climate so that it is favourable for man—is not borne in mind in all stages of the planning process. Hitherto, the effects of locating a polluting works on the regional climate have been disregarded. Little account has been taken of the way in which distributing green spaces and formulating town blocks affects the climate of urban areas. Insufficient attention is paid to the way in which the orientation and design of an individual building and the surrounding vegetation will influence the climate in the outdoor areas around the building. Sometimes, calculations are made of the changes between the outdoor and indoor heat climates that would occur as a result of the particular construction and material composition employed on the building, but these are used primarily as a means of defining the initial conditions for climatic control installations and not for determining the joint climatic properties of the building. Another explanation of this uneconomic climatic planning is that the aim of climatic modification has been incorrectly formulated. Hitherto, endeavours have been made to create an indoor climate that keeps the physical environment of man in a static condition. This condition has been termed the ‘comfort climate’. This has been defined as those values of the elements of the physical environment that deliver neutral information to the sensory organs. If one wishes to be controversial, one can say that the aim of climatic planning has been to create a ‘comfort climate’, which effectively prevents man from receiving stimulating information from his surroundings. More economical climatic planning calls for a definition of the ideal climate to suit the way in which people function. This paper discusses the need to define human environmental requirements as a basis for more conscious cooperation between planners, architects and engineers as well as a basis for developing products in the heating and ventilating industries.
Low-Cycle Fatigue under Biaxial Stress
Authors: Parsons M. W. , Pascoe K. J. 
Published: October 2007

The low-cycle fatigue behaviour of a ferritic and an austenitic steel have been studied under various conditions of reversed biaxial strain. These cyclically softened and hardened respectively. In all cases, relationships of the form were found between total strain range Δε t and life Nf for lives in the range 102−105 cycles, with an abrupt change of β at intermediate lives. Variation of state of strain affected both β and κ. Various theories for the correlation of fatigue behaviour under multi-axial loading have been reviewed and compared with these results. None was found to account adequately for the effect of straining régime with the materials tested.
The Role of the Mechanical Engineer in the Environmental Problems of a Developing Technological Society
Authors: Crossland B. 
Published: October 2007

The lecture briefly reviews the current fears for the future of civilization as we know it. It considers in greater detail the problems of the population explosion, the exhaustion of energy supplies, the exhaustion of raw materials and the pollution of our environment. It refers briefly to the study of pollution problems, or the whole world problem, by the creation of models and application of system dynamics to them as a method which may ultimately be able to provide predictive guidance to the most appropriate courses of action. The most serious problem is still the population explosion. The lecture discusses the contributions of engineers in providing solutions to the problems of energy and materials utilization and in overcoming pollution problems, and emphasizes the essential need for a much stronger professional body for engineers. Finally, it points to the need to introduce engineering students to these problems and the desirability of an ethical code which includes reference to the necessity of conserving energy and materials and avoiding unnecessary pollution.
The Use of Accident Data in Studying Vehicle Handling Performance
Authors: Jones I. S. 
Published: October 2007

A study to establish the relation between vehicle handling performance and accident causation. Since deficiencies in handling are likely to be associated with accidents involving loss of control, measures of handling which are likely to express proneness to loss of control are first suggested; emphasis is placed on simplicity of measurement to allow as many different models of car as possible to be included in the study. Accident rates for the various types of accident which are likely to be influenced by these parameters are then determined by model of car. The effect of other factors, such as variation in driver characteristics between different models of car on these rates is then assessed so that the relation between handling characteristics and accident frequency can be defined. Finally, the relative importance of the various measures of handling suggested are assessed. The results suggest that there is a definite relation between handling performance and accident causation although it is relatively small when compared to driver effects. In explaining the variation in the accident rate between different models of car, driver effects account for as much as 70 per cent; if driver effects are removed from the accident rate then handling parameters explain between 35 and 40 per cent of the remaining variation between models of car. The important parameters appear to be weight, a measure of the change in understeer as a function of lateral acceleration and power to weight ratio.
Rope in the Marine Environment
Authors: Sharp D. M. 
Published: October 2007

Rope has always been an important item in the marine environment. The transition from one type of construction to another, notoriously slow: for example, rope of both wire and fibre supplied to the S.S. ‘Great Britain’, launched in 1843 was of a similar type and quality to that which would be equally familiar to our mariners a century later. Many having experience in this latter period might recognize some similarity with the rope in use today but there have been substantial changes, and these changes have occurred not specifically because of any major breakthrough in rope design and production, although there have been very substantial advances in these sectors but because the detail of today's and tomorrow's applications have themselves changed. The paper examines a number of the major applications involving rope in the marine environment, and shows how rope characteristics must be recognised and wedded to the duty parameters if optimum performance is to be achieved.
The Price of Safety
Authors: McNaughton I. K. A. 
Published: October 2007

The author shows how railway safety has developed, usually in reponse to public opinion, to the high standard of today. He traces the significant improvements in safety that have been achieved during the past 15 years and discusses the extent to which further improvements might be justified. The lecture also raises the possibility thai, for certain lines, some relaxation of the current safety requirements, with consequent cost savings, might be made without a significant lowering of safety standards.
Design and Performance of an Automatic Control System for Fastener Tightening
Authors: Boys J. T. , Wallace P. W. 
Published: October 2007

Methods of controlling the tightness of bolted assemblies by presetting the torque or bolt rotation are reviewed. It is shown that these produce either inaccurate clamp loads or excessive elongation of the fastener. As a result the tightening operation is often the weakest link in obtaining a reliable assembly. The development of a system of tightening control that overcomes these problems is described. It operates by sensing the gradient of the torque-rotation characteristic, thus detecting the yield point of the fastener. In principle it requires no preset control torques or rotation angles. Comparative results show that the system increases bolt clamp loads and reduces their scatter very significantly.
Heat Transfer to a Pvd Rotor Blade at High Subsonic Passage Throat Mach Numbers
Authors: Martin B. W. , Brown A. , Garrett S. E. 
Published: October 2007

This paper reports heat-transfer measurements round a PVD rotor blade using a transient method. Instrumented syndanio-asbestos blades forming part of a cascade are suddenly introduced into a heated air stream, the temperature-time response of surface thermocouples attached to copper inserts in the blades then being used to determine local heat-transfer coefficients for (a) passage throat Mach numbers between 0.79 and 0.94 (b) turbulence intensities from 4.15 to 9.05 per cent (c) blade chord Reynolds numbers from 7.8 times 105 to 8.9 times 105. Measured transition lengths on the suction surface, over which the heat transfer nearly trebles, are somewhat short in relation to other measurements. The onset of transition, which is downstream of predictions for the higher Reynolds numbers but accords with the trends of existing correlations, is little influenced by turbulence intensity variations in the above range. Over the pressure surface the heat transfer is less than for a fully-turbulent boundary layer. Comparisons with other high Mach-number measurements suggest that much further work is needed before the effects of scale of turbulence are fully understood.
The Engineering of Reliability into Waste Heat Boiler Systems
Authors: Hinchley P. 
Published: October 2007

Waste heat boiler systems are often a weak link in process plants and some failures have caused severe losses. The author considers that this situation can be avoided in future plants by following the guidelines laid down in the paper. The paper begins with a general description of a waste heat boiler system which is applicable to all processes. The evolution of the flowsheet for a typical plant is described and it is shown how the early involvement of engineering specialists can influence the choice of steam conditions and the positioning of items of equipment in the flowstreams, so as to ensure that reliable equipment can be designed and purchased. The early development of a computer model of the system is recommended since it frequently demonstrates how the duties of individual items deviate markedly from normal, under start-up, part-load and trip conditions. The various items of plant are described, potential problems are mentioned and methods of avoiding them given. In the case of boilers heated by process gas, reference is made to some of the special designs that have been developed for specific processes. The need to acquaint the equipment supplier of the special problems of a particular process is stressed, as is the importance of close attention to detailed design, fabrication and quality control. The main pre-commissioning steps are described. In operation, water quality is vital and continuous analysers are advocated in specified locations, with some linked to automatic trips which prevent contaminated condensate or feedwater from entering the treated water storage tank or deaerator.
Compressible Flow through a Butterfly Throttle Valve in a Pipe
Authors: Woods W. A. , Goh G. K. 
Published: October 2007

This work is put in perspective by mentioning some of the applications of butterfly throttle valves and explaining how the next tests are complementary to other work (1). The present tests examine the flow characteristics of a butterfly throttle valve in relation to valve opening, pressure ratio and circumferential and axial location of the pressure tappings. The paper gives results of a comprehensive series of steady flow tests and, also, results of a limited number of unsteady flow tests. In the latter, the butterfly throttle valve was located in the intake system of a single cylinder diesel engine. The paper highlights the importance of the position of pressure tappings when pressure measurements are used to estimate flow rates. The results of the present study show that when suitable precautions are taken the quasi-steady flow method may be used to predict the flow rates under pulsating conditions.
Analogue and Digital Modelling in the Design of a Hydraulic Vehicular Transmission
Authors: Svoboda J. V. 
Published: October 2007

This paper is concerned with the design and development of a hydraulic hybrid urban vehicle power plant using a small internal combustion engine prime mover, a hydraulic transmission, and a hydraulic accumulator as a small energy store. The driver controls the vehicle velocity by operating the swashplate of the axial-piston variable-displacement hydraulic motor. The remaining system inputs, i.e., the engine throttle and swashplate of the axial-piston variable-displacement hydraulic pump, are governed by a multiloop electronic controller via electro-hydraulic servo-actuators. The system aims to achieve a high overall efficiency by utilizing the hydraulic accumulator to maintain optimal loading of the prime mover and to provide regenerative braking. The design was aided by an analogue simulation implemented on an EAI 690 hybrid computer. For the final quantitative evaluation of the system, a digital simulation program was written using the MIMIC processor. Realistic modelling was attained in both cases by using manufacturers' data for commercially available components to define the dynamic response and efficiency of the individual elements of the overall system. The simulation model was subjected to accelerator/decelerator step input signals under various road conditions. ‘Drives’ through the standard LA-4 and EPA standard urban cycles were performed. The simulation results showed high system stability, satisfactory acceleration and deceleration performance and a good overall efficiency.
The Steady State Hydrothermal and Chemical Environment of a Once-Through Boiler Operating at 14.5 MPa
Authors: Crow I. G. , Greene J. C. , Tyldesley J. D. , Walker M. A. 
Published: October 2007

The chemical, thermal and hydrodynamic conditions present on the waterside of a once-through nuclear boiler operating under steady conditions at a pressure of 14.5 MPa have been studied in a recirculating test loop operating at plant relevant conditions. By means of a highly sensitive scanning gamma-ray detector system and the use of radio-labelled sodium chloride, together with conventional hydrothermal instrumentation a comprehensive description of the waterside environment has been obtained. A previously unsuspected form of sodium hold-up in the test-section has been observed and attributed to an adsorption process. The amount of sodium adsorbed has been found to be dependent upon the dry area of the tube available, the temperature of the metal and the ratio of sodium chloride to hydrogen chloride in the working fluid.
Variable Amplitude Fatigue in Relation to Highway Bridges
Authors: Tilly G. P. , Nunn D. E. 
Published: October 2007

With the introduction of welded construction in highway bridges it has become necessary to assess designs for fatigue. Current methods of calculating endurances involve constant amplitude data and assumption that the Palmgren-Miner law can be used to sum the damage caused by different stresses. In order to investigate the efficacy of this method laboratory tests have been conducted on representative welded connections using variable amplitude loading at endurances of up to 415 × 106 cycles. Using a Rayleigh spectrum of stresses it is shown that for endurances relevant to bridge service, the role of stresses below the constant amplitude fatigue limit is critically important. If they are ignored, calculated endurances can be many times too optimistic. An accurate allowance for the effects of low stresses can be made by representing the constant amplitude data by a curve having a higher stress exponent for stresses below the fatigue limit. At the longest endurance tested, only about 0.25 per cent of the stresses exceeded the fatigue limit and these caused 9 per cent of the calculated damage. Under an axle load spectrum, endurances were six times longer than calculated. This was found to be due to an interactive effect caused by small numbers of high stresses which effectively retard the rate of crack propagation. In practice, shapes of stress spectra differ from axle load spectra and situations in which measured stresses involve small numbers of high values are rare. In all cases, conservative endurances were estimated using the method given in the British Standard for bridge design.
A Full Shift True Breathing Zone Air Sampler and Its Application to Lead Workers
Authors: Allen J , Bellinger E G , Higgins R I 
Published: October 2007

A completely head-mounted full shift dust sampler for monitoring the lead-in-air concentration in a lead worker's actual breathing zone is described. A small filter head is positioned within 5 cm of the mouth and nose on an adjustable stalk. Air is drawn through a 1.25 cm diameter glass fibre filter at a rate of 0.51/min by a small rotary vane pump. Initial comparisons with a conventional lapel-mounted UKAEA head powered by a Casella pump show that the average lead-in air concentration in the true breathing zone can be significantly different from that around the lapel.
Plastic Buckling of Torispherical and Ellipsoidal Shells Subjected to Internal Pressure
Authors: Galletly G D 
Published: October 2007

Thin metallic torispherical shells are used frequently in many industries as end closures on cylinders subjected to internal pressure and, for those torispheres which have diameter/thickness ratios greater than 400, elastic-plastic internal pressure buckling may occur. As yet, however, code rules to assist the designer with this buckling problem are not available in either the UK or the USA and one of the aims of this paper is to help to correct this situation. Elastic-plastic internal buckling pressures, for a range of perfect torispherical geometries and obtained with the aid of a sophisticated computer program, are given in the first part of the paper. These pcr's are then utilized (a) to develop a relatively simple equation for predicting the internal buckling pressures of torispherical shells and (b) to assess the accuracy of another, even simpler, approximate buckling equation which was suggested recently (1). Next, the correlation between the theoretical predictions of pcr and the experimental results is considered. The tests taken into account were (a) 5 in diameter machined model torispherical shells, (b) 20 in diameter spun ellipsoidal shells, and (c) 54 in diameter pressed and spun torispherical shells. The shells in (b) and (c) were not stress-relieved and a number of them were made from strain-hardening materials. The agreement between theory and experiment was good for the machined models and fairly satisfactory for the spun models. For the ellipsoidal shells there was also reasonably good agreement between the predictions of two simple design equations and the experimental results. The problems associated with the prediction of the internal buckling pressures of spun torispherical shells made from strain-hardening materials (e.g. stainless steel) are considered in the last section of the paper. Taking the results of the previous sections of the paper into account, and making some simplifying assumptions, a tentative design procedure for predicting the pcr's of these ‘as-manufactured’ spun torispherical shells is proposed. This procedure is then checked by comparing its predictions with experimental buckling pressures found for eleven spun stainless steel heads and six crown and segment ones. The agreement between experiment and theory was quite satisfactory and it is hoped that the suggested procedure might become the first step towards the development of experimentally validated code rules for preventing the occurrence of buckling in these dished ends.
The Development of the Prototype Advanced Passenger Train
Authors: Boocock D , King B L 
Published: October 2007

The development and performance of British Railways' three prototype Advanced Passenger Trains (APT-Ps) are discussed. The progression from design concept to construction, commissioning and testing prior to entry into passenger service is described. Performance aspects of the train and its sub-systems are assessed in relation to technical objectives. The commissioning programme and highlights of the track proving trials are described. Important test results are discussed, including those relating to body tilt systems, ride quality, lateral track forces, braking performance, current collection, and thyristor interference. Account is given of various development problems which arose during commissioning trials and endurance running. The paper concludes with a brief description of the design of the production train (APT-S), which is planned for fleet operation on BR's electrified West Coast routes.
The Use of Increased Wheel Flexibility to Improve Chatter Performance in Grinding
Authors: Sexton J S , Howes T D , Stone B J 
Published: October 2007

The metal removal rates attainable during grinding may often be limited by the onset of an unstable vibration, commonly called regenerative chatter. Chatter is a self-induced vibration which leads to increased power consumption, a poor, generally unacceptable, ***workpiece surface finish, uneven wear of the grinding wheel and, in some cases, actual damage to the wheel. It is known that chatter is more likely to occur when the grinding wheel is hard and for this reason chatter often develops when grinding with diamond or cubic boron nitride (CBN) wheels, whose chief characteristic is that they are very hard-wearing. This paper describes the development of a technique for suppressing chatter which is particularly applicable to the use of diamond and CBN wheels. It has been predicted theoretically and confirmed by experiment that chatter may be suppressed, or even eliminated, by increasing the radial flexibility of a grinding wheel, whilst at the same time maintaining high values of the wheel's natural frequency and damping. It has been shown that the increased flexibility may be achieved by mounting the abrasive rim of the wheel via a flexible coupling, or by manufacturing a wheel by conventional means but with a flexible hub material. Both techniques are successful and diamond and CBN wheels, manufactured to these designs, have performed substantially better than conventional ultra-hard abrasive wheels currently marketed. It is considered that the problem of chatter when using diamond or CBN wheels has been solved. Since this problem has represented one of the major obstacles to the acceptance of CBN wheels by industry, it is anticipated that these wheels will now enjoy a much more widespread usage.