Showing papers by "Cranfield University published in 1985"
TL;DR: In this article, the authors studied the extent to which the entrepreneur interacts with the networks in his local environment during the process of starting a new firm, based on the premise that, during this process, he is seeking not only the resources of equipment, space, and money, but also advice, information, and reassurance.
1,780 citations
TL;DR: The I7 Impulsiveness Questionnaire as mentioned in this paper is a modified version of the original I5 Questionnaire with seven factors (i.e. psychoticism, extraversion, Neuroticism, Lie score, impulsiveness Venturesomeness and Empathy).
1,166 citations
TL;DR: In this article, the aerothermochemistry of premixed turbulent combustion is used to develop a Reynolds stress/flux description of a flow field consisting of constant density regions of either reactants or products and of reaction zones in which density fluctuations arise as a consequence of heat release.
390 citations
TL;DR: Electrochemical, optoelectronic and calorimetric approaches to sensing are considered and it is concluded that configurations based either on hydrogen peroxide detection or on mediated electron transfer are most likely to provide a raid route to in vivo monitoring.
288 citations
TL;DR: In this article, the authors look at the author's beliefs concerning the ways in which production planning and control should be developed in the future and see the way forward as one which includes small factories - even if the companies are large - less specialisation; simple materials flow systems; Flexible programming; PBC or Kanban and the development of systems theory.
229 citations
TL;DR: In this article, the suitability of three fluorinated hydrocarbons (R-11, R-113 and R-114) as refrigerants for a Rankine-cycle system was investigated.
210 citations
TL;DR: Some of the partial differential equation (p.d.e.) models which have been used by agricultural engineers in detailed simulations of deep bed drying and discussion of these in the light of a general p.e. model developed recently by Laws and Parry are presented.
206 citations
TL;DR: In this article, the authors proposed a finite element method to solve the stationary form of the Fokker-Planck-Kolmogorov equation for the random response of a certain class of non-linear systems.
96 citations
TL;DR: In this article, the stability of a viscous, current-carrying fluid cylinder with surface charge was investigated in the context of metal transfer in arc welding and it was found that viscous effects are negligible while electrostatic effects exert a stabilising influence and may have interesting effects on stability.
Abstract: This paper considers, largely in the context of metal transfer in arc welding, the stability of a viscous, current-carrying fluid cylinder with surface charge. Simple expressions are obtained between the characteristics of instability growth and the dependence of these on 'process parameters'. For liquid metals it is found that viscous effects are negligible while electrostatic effects exert a stabilising influence and may have a number of interesting effects on stability (particularly at low wire currents).
94 citations
TL;DR: In this article, the stability of a 3D laminar boundary layer formed on a curved surface is considered and a calculation scheme which takes account of the curvature of the flow streamlines and of the surface is proposed for the prediction of the development of small amplitude temporal disturbances.
Abstract: The problem of the stability of a three-dimensional laminar boundary layer formed on a curved surface is considered. A calculation scheme, which takes account of the curvature of the flow streamlines and of the surface is proposed for the prediction of the development of small amplitude temporal disturbances. Computations have been performed for the flow over the windward face of an infinitely long yawed cylinder and comparisons have been made with experimental data. These indicate that the theory correctly predicts many of the features of the unstable laminar flow. The theory also suggests that transition, in this particular situation, is dominated by traveling disturbance waves and that, at the experimentally observed transition location, the wave which has undergone greatest total amplification has an amplitude ratio of approximately e to the 11th. When the effects of curvature are omitted the maximum amplitude ratio at transition is about e to the 17th.
87 citations
01 Jan 1985
TL;DR: Before embarking on an automated assembly project, a user would be well advised to look beyond the mechanical performance of the rival machines and to look closely at the software features offered.
Abstract: Many robot manufacturers claim that their machines are suitable for assembly operations, but before embarking on an automated assembly project, a user would be well advised to look beyond the mechanical performance of the rival machines and to look closely at the software features offered.
TL;DR: In this article, a ternary diagram of polyester resins containing polyvinyl acetate (PVA) is presented. But it is concluded that these particles consist of resin sub-inclusions embedded in the continuous matrix of a polyester resin, and that increasing the PVA content to 16% results in a phase inversion.
TL;DR: In this paper, a buoyant, turbulent natural gas flame burning on a porous refractory burner, 25 cm in diameter, is compared with numerical predictions using a parabolic formulation, k-ϵ turbulence modeling and a flamelet description for combustion chemistry.
TL;DR: In this paper, the corrosion of carbon manganese steel in CO2-acidified sea water has been assessed by a statistical analysis of corrosion profiles and the time dependence of the extreme value distribution parameters has been determined and used to predict the rate of penetration of steel components under pitting conditions.
TL;DR: In this paper, an experimental investigation of the steady-state rates of heat transfer from an array of vertical rectangular 3 mm thick fins, extending 60 mm perpendicularly out of a 250 mm high vertical rectangular base, was reported.
01 Jul 1985-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: In this article, a multiple capacitive transducer has been developed to simplify the measurements, and to increase their accuracy, using large-area sensors reduces the effects of out-of-roundness and misalignment of the master cylinder.
Abstract: The measurement of errors in the axis of rotation is of increasing interest, and considerable work has been done to improve understanding of the effects of these errors on machined workpieces. In an attempt to simplify the measurements, and to increase their accuracy, a multiple capacitive transducer has been developed. Use of large-area sensors reduces the effects of out-of-roundness and misalignment of the master cylinder. Instrument errors less than 10 nm have been demonstrated. A combination of digital and analogue circuitry reduces set-up time to a minimum, and facilitates rejection of the once-per-revolution components at any speed.
TL;DR: In this article, an experimental investigation of the steadystate rates of heat transfer from an array of vertical rectangular fin of 3 mm thickness and 250 mm length, protruding 60 mm perpendicularly upwards from a 250 mm × 190 mm horizontal rectangular base, is reported.
TL;DR: In this article, a mathematical model has been developed to describe the loss of contact between the vanes and the stator-cylinder, which results in significant internal leakage losses.
TL;DR: In this paper, three different methods of rapidly cooling specimens prior to microscopical analysis are currently in use, namely, slamming, plunging and spraying, and the heat transfer processes and specimen cooling rates which are theoretically achievable by each method are discussed and compared with some of the published experimental data.
Abstract: SUMMARY
Three different methods of rapidly cooling specimens prior to microscopical analysis are currently in use, namely, slamming, plunging and spraying.
The heat transfer processes and specimen cooling rates which are theoretically achievable by each method are discussed and compared with some of the published experimental data.
For the slamming method it is concluded that very little improvement in specimen freezing will be achieved by pre-cooling the block below about 20 K and where pure silver is the most efficient block material.
The highest cooling rates and best microscopy by either the plunging or spraying method will be achieved using nitrogen at supercritical pressures. At subcritical pressures propane will produce the best results for metal samples whereas ethane is superior to propane for exposed biological specimens.
Future experimental work which relates ice crystal size to cooling rate must be based on the cooling rate at the instant of freezing or nucleation and not on some average cooling rate.
TL;DR: In this article, a two-dimensional burner-flame stability with arbitrary gas expansion is discussed with a porous-plug-type flame holder, and it is shown that the influence of the holder and the acceleration due to gravity are important factors governing the onset of cellularity in porousplug burner flames.
Abstract: Two-dimensional burner-flame stability is discussed with arbitrary gas expansion. Density variations are allowed for by fully coupling the continuity and momentum equations. The flame is assumed to be close to a porous-plug-type flameholder so that the conventional hydrodynamic zone upstream of the flame cannot be included. Instead, the flow is assumed to obey a Darcy-type law within the holder, relating pressure gradient and velocity. It is shown that the influence of the holder and the acceleration due to gravity are important factors governing the onset of cellularity in porous-plug burner flames. Further, the balance of the transverse and longitudinal Darcy constants used to describe the upstream hydrodynamic zone within the holder have a vital effect on stability predictions. Experimental observations are confirmed by the theory presented.
TL;DR: In this article, the authors propose a modelle mathematique plus complexe qu'anterieurement, which is capable of prendre en compte des facteurs additionnels.
Abstract: Le processus de pompage dans un compresseur centrifuge depend d'un certain nombre de facteurs complexes et souvent relies entre eux. On propose un modele mathematique plus complexe qu'anterieurement qui est capable de prendre en compte des facteurs additionnels. Bon accord avec les etudes experimentales. Ce modele considere les pertes de charge dans la roue, dans le diffuseur, et dans le collecteur, et il est possible d'identifier les elements de decrochage qui sont responsables de l'instabilite globale du compresseur
TL;DR: In this article, the effects of the geometrical parameters of the expanders on their performances were discussed, and it was shown that the neglect of the vanes' thickness when evaluating the geometry of expanders can lead to considerable errors in their predicted volume expansion ratios, especially when numerous vanes and small inlet angles are employed.
TL;DR: In this paper, a mathematical model for predicting the flow rates via internal leakage paths in an MVE has been developed, where the major leakage channels were indentified, and a mathematical approach was developed to predict the flow rate via them.
TL;DR: In this article, the authors measured the steady-state rates of heat loss from an array of 3 mm thick, 250 mm long, horizontal rectangular duralumin fin extending 60 mm perpendicularly out of a 250 mm × 190 mm vertical rectangular base, at a uniform temperature of between 40°C and 80°C.
TL;DR: In this article, an heuristic for the planning and study of machine-component groups in flexible production cells and flexible manufacturing systems is presented, where the problem of group formation defined on master-component process routes is undertaken in terms of minimum differences between masters and maximum combinations of masters.
Abstract: This paper provides an heuristic for the planning and study of machine-component groups in flexible production cells and flexible manufacturing systems. The problem of group formation defined on master-component process routes is undertaken in terms of minimum differences between masters and maximum combinations of masters. Group formation is a ‘hard’ combinatorial problem subject to exponential growth of complexity as the number of decision-making variables increases. The heuristic is designed to search the solution space of the problem in monotone-increasing order of solution costs so as to avoid the enumeration of solutions for cost minimization.
TL;DR: In this article, the authors found that six months' practice of Transcendental Meditation produced an improvement in postgraduate academic performance in the first year of an MSc course at the Cranfield Institute of Technology.
Abstract: Summary. Twenty students taking the first year of an MSc course at Cranfield Institute of Technology were randomly allocated to a Transcendental Meditation or control group. There was some evidence that six months' practice of Transcendental Meditation produced an improvement in postgraduate academic performance.
TL;DR: The paper raises a number of questions which could form the basis for useful research in this area and some suggestions for practical algorithms outlined.
19 Jun 1985
TL;DR: Multi-vane expanders possess many advantages as prime movers for organic Rankine-cycle power systems utilising low grade energy as the heat inputs, particularly for low power outputs.
TL;DR: In this article, computer sub-routines have been developed for calculating the properties of refrigerants R-11, R-12 and R-13 as functions of their characteristic parameters at a state point.