bluuebunny/crossref_metadata_2025 huggingface dataset:
The more, the merrier? Multiple developmental relationships and work satisfaction
Authors: Higgins Monica C.
Published: July 2002

The context of the present study is the early careers of lawyers. I examine if and how receiving “more” mentoring – in terms both of number of relationships and amount and type of assistance received – affects individuals’ satisfaction at work. Results suggest that the more developmental relationships an individual has and the more developmental assistance he or she receives, the greater will be his or her work satisfaction. Findings also suggest, however, that receiving a high amount of psychosocial assistance from just one person, who is not necessarily of higher status, is associated with high work satisfaction. Practical implications and suggestions for future research that explores the effects of multiple developmental relationships in other contexts are discussed.
Building regulation and sustainable housing. Part 1: a critique of Part L of the Building Regulations 1995 for England and Wales
Authors: Bell Malcolm , Lowe Robert
Published: July 2002

This paper presents a critique of the energy efficiency aspects of the Building Regulations for England and Wales as they relate to dwellings. It is argued that a significant improvement in the regulations is required if large reductions in CO2emissions are to be achieved in the first half of the next century and that considerable scope for regulation improvement exists (almost 90 per cent reductions in space heating are achievable). The paper identifies the shortcomings of the methods used to demonstrate compliance and proposes new approaches which would increase consistency and enable a clear programme of improvement to be established.
A Proactive Model for Training Needs Analysis
Authors: Anderson Geoff
Published: July 2002

The focus of training needs analysis is typically job performance. If
people lack the knowledge or skills necessary to perform successfully
the various tasks which comprise their jobs we have identified a
training need. If another factor is hindering performance, such as
faulty equipment or low morale, we have identified another type of need.
We concentrate on job performance because it is observable and because
it synchronizes with the behaviourist model of learning which figures so
prominently in most thinking about training. It could well be argued
that this deficiency approach is no longer adequate in our present
environment in which the very nature of jobs and competences is subject
to constant change. Argues for a more proactive, strategically based
approach and suggests key issues which will need to be addressed at each
stage of the process.
The Spanish VET system at the turn of the century: modernization and reform
Authors: Martinez Celorrio Xavier
Published: July 2002

Places the reform of the Spanish vocational education and training (VET) system in context, identifying the salient events and deficiencies in this modernization process. The most significant reaction to the need for improving, rationalizing and modernizing the former vocational training system was the development of the National Programme for Vocational Training in 1993. After several years’ negotiations, in 1992 the employers’ associations and trade unions signed the National Agreement on Continuing Training, which has given a notable impulse to this type of training in the last four years. It has been the first opportunity to set up a regulatory framework for the allocation of public funds to promote open access to continuing training for the employed populations. In 1996 the second plan was agreed, shoring up a sectoral model organized through collective agreements which aims to enrich the Spanish industrial relations model. Finally, analyses the new problems and deficiencies which could neutralize the reform’s innovative effects, as happened in the last reform under different historical conditions (1970). The success of a new Spanish VET system depends on actors’ capability to shore up a professionalized model for management and provision.
Investigations of the audible noise of inductors with respect to different ferromagnetic materials
Authors: Terörde Gerd , Schneider Jürgen , Hameyer Kay
Published: July 2002

Fluorescent lamps are one of the most modern light sources. They can be connected to the 230Vac supply without a transformer. To operate them, an inductor and starter are required only. The main disadvantage of this type of light source is the emitted audible noise of a frequency of 100Hz. For this phenomenon the inductor is responsible. Electromagnetic forces and magnetostriction are acting on the body of the device causing the sound emission. Here, the audible noise problem is investigated with respect to different ferromagnetic materials and the range of applied flux densities inside the iron core.
A planar flexible robotic manipulator
Authors: Orlando Gamarra‐Rosado Víctor
Published: July 2002

Presents the dynamic modelling of a flexible robotic manipulator with two flexible links and two revolute joints, which rotates in the horizontal plane. The dynamic equations are derived using the Newton‐Euler formulation and the finite element method, based on elementary beam theory, which is used to discretize the displacements such that the small motion is represented in terms of nodal displacements. Computer simulation results are presented to illustrate this study. The dynamic model becomes necessary for use in future design and control applications.
Quantum coherence and conscious experience
Authors: Ho Mae‐Wan
Published: July 2002

Proposes that quantum coherence is the basis of living organization and can also account for key features of conscious experience: the “unity of intentionality”; our inner identity of the singular “I”; the simultaneous binding and segmentation of features in the perceptive act; the distributed, holographic nature of memory; and the distinctive quality of each experienced occasion.
The business school in the new millennium
Authors: Vinten Gerald
Published: July 2002

Controversy has always surrounded business schools: they are almost regarded as a necessary evil. Their credentials have been impugned from within academia, and from the outside business community. Periodically committees are formed and reports written on how to overcome the perceived deficiencies. From contemporary literature themes emerge, and the opportunity is taken to both look back and to look forward. Globalisation, partly mediated through the Internet, presents even greater challenges, as do the rise of corporate and virtual universities, heightened competition among schools, finding and nurturing appropriate staff, achieving critical mass and serving the entire economy, working with relevant partners inside and outside the university setting, maintaining quality, and undertaking research meeting the needs of various constituencies. Schools cannot be all things to all people, and need to prioritise their mission objectives in the light of those stakeholders for whom they will decide to dedicate most of their energies.
Marketing schools and consumer choice
Authors: Harvey Janet A.
Published: July 2002

States that the concept of marketing is regarded with suspicion by many in education because of its commercial implications. Marketing is seen as a potential tool for the application of market forces and is therefore regarded as ethically undesirable. Argues that the methods and ideology of commercial marketing, if properly understood and correctly applied by professionals in education, can be beneficial rather than harmful, and may be imperative for schools and colleges wishing to attract students and to offer them the most relevant provision.
Stencil design for mixed technology through‐hole/SMT placement and reflow
Authors: Coleman William E. , Jean Denis , Bradbury‐Bennett Julie R.
Published: July 2002

Reviews stencil design requirements for printing solder paste around and in through‐hole pads/openings. There is much interest in this procedure since full implementation allows the placement of both through‐hole components as well as surface mount devices and the subsequent reflow of both simultaneously. This in turn eliminates the need to wave solder or hand solder through‐hole components. The effect of component material type, pin type, lead length, and standoff height of the through hole components is reviewed. Board design issues including plated through‐hole size, pad size, board thickness, and solder mask type are also reviewed. Three stencil designs are considered: single thickness stencils with oversized stencil apertures for overprinting solder paste in the through‐hole pad areas; step stencils with oversized stencil apertures for overprinting solder paste in the through‐hole pad areas; thick stencils (0.384‐0.635 mm thick) for printing solder paste in the through‐hole pad areas. The latter thick stencil is the second stencil in the two‐print stencil process. Several examples are reviewed with the recommended stencil designs.
Direct response advertising in the US and European markets: a content analysis of fashion products
Authors: Seitz Victoria
Published: July 2002

In the advertising of self‐projective products, marketers have focused on image advertising. However, today advertisers are integrating direct response with image based advertising, in essence, to “get more bang for the buck”. Hence, the purpose of the study was to investigate direct response advertising in upscale fashion magazines in the European Union as well as the USA. Eight hundred and seventy advertisements of perfumes, women’s apparel and cosmetics were evaluated via the editions of Vogue. Direct response advertisements were most prevalent among advertisements of women’s apparel and primarily in US editions of Vogue. Furthermore, advertisements for perfumes and women’s apparel were image based while advertisements for cosmetics were balanced. Implications of the findings are given regarding advertising fashion products in the European Community.
Objective hand evaluation of non‐wovens used for nappies
Authors: Yokura Hiroko , Niwa Masako
Published: July 2002

Describes an investigation into the hand of non‐wovens used for nappies under both dry and wet conditions. The mean score of the subjective hand assessments (THVsub) of dry nappy was correlated with their surface properties which are obtained using the single wire U‐shape sensor.
Water transfer properties of two‐layer weft knitted fabric
Authors: Long Hai‐Ru
Published: July 2002

The aim of this study is to investigate the water (moisture vapor and liquid) transfer properties of two‐layer weft knitted fabric and some related factors. Some experimental fabrics with specific yarns and stitch densities were prepared. Water vapor permeability rate through the fabrics and liquid water transfer from inner to outer layers were measured. The results show that the permeability rate is closely related to the porosity within the fabric while the transfer depends mainly upon the water absorption properties of the fibers on the two layers and degree of their difference.
Leadership for successful inclusive schools
Authors: Guzmán Nadyne
Published: July 2002

Describes a multiple case analysis of six elementary school principals considered to be successful as leaders of inclusive schools. Analyses the structural and behavioural factors present in six elementary schools considered to have successfully included students with disabilities in regular classroom programmes. Outlines several factors which were found to be common among the principals of the six schools. Each principal: established a system of communication that allowed staff members to disagree with policies and practices and to make recommendations for changes; was actively involved in the IEP development process; was personally involved in dialogue with the parents of students with disabilities; worked with staff to agree collaboratively on a building philosophy of inclusion; established policies for addressing specific discipline issues arising from students with disabilities; followed a personal plan of professional development regarding issues of inclusion; demonstrated skills in data gathering; and demonstrated skills in problem solving.
Managing diversity in the hotel sector: the emergence of a service quality opportunity
Authors: Maxwell G. , McDougall M. , Blair S.
Published: July 2002

Interest in managing diversity has grown in recent years. From origins in the USA, and initial interest in the idea and ideals of managing diversity, the focus of current attention in managing diversity tends to be on its organisational implications and benefits. This article discusses the concept of managing diversity in relation to service quality, a critical goal and priority for all hospitality organisations. It examines the practicalities and potential of managing diversity. Reference is made to case study analyses of UK hotel chains which indicates that, in this sector, approaches to managing diversity are reasonably well developed and are closely linked to enhanced service quality.
The Stokes problem for a dusty fluid in the presence of magnetic field, heat generation and wall suction effects
Authors: Chamkha Ali J.
Published: July 2002

This work focuses on the laminar flow of a two‐phase particulate suspension induced by a suddenly accelerated infinite vertical permeable surface in the presence of fluid buoyancy, magnetic field, heat generation or absorption, and surface suction or blowing effects. The governing equations for this modified Stokes problem are developed based on the continuum representation of both the fluid and the particle cloud. Appropriate dimensionless variables are introduced. The resulting dimensionless equations are solved numerically by an accurate implicit finite‐difference method for two situations. The first case corresponds to an impulsive start of the surface from rest while the second case corresponds to a uniformly accelerated surface. The numerical results for these cases are illustrated graphically. Comparisons with previously published work are performed and the results are found to be in good agreement. Typical fluid‐ and particle‐phase velocity and temperature distributions as well as wall shear stress and heat transfer results are reported for various values of the particle loading, Hartmann number, wall mass transfer coefficient and the heat generation or absorption coefficient.
Numerical analysis of combined radiation and unsteady natural convection within a horizontal annular space
Authors: Naceur Borjini Mohamed , Mbow Cheikh , Daguenet Michel
Published: July 2002

The effect of radiation on unsteady natural convection in a two‐dimensional participating medium between two horizontal concentric and vertically eccentric cylinders is investigated numerically. The equations of transfer are written by using a bicylindrical coordinates system, the stream function, and the vorticity. The finite volume radiation solution method and the control volume approach are used to discretize the coupled equations of radiative transfer, momentum, and energy. Original results are obtained for three eccentricities, Rayleigh number equal to 104, 105, and a wide range of radiation‐conduction parameter. The effects of optical thickness, wall emissivity, and scattering on flow intensity and heat transfer are discussed.
BS 5750 parts 1 and 2/ISO 9000 (series); 1987 and education –
do they fit and is it worth it?
Authors: Doherty G.D.
Published: July 2002

Divided into four sections, first describes the institutional
context and why the University of Wolverhampton decided to become
engaged in a TQM initiative. Next describes how the university,
discovering the TQM approach to be attractive but difficult to target,
moved towards BS EN ISO 9001. There is a brief discussion of the pros
and cons of each. Outlines some of the fundamental aspects of designing
a quality management system, especially understanding the nature of the
product and the importance of its design. Finally discusses the costs
(which are difficult to assess accurately), and benefits of the exercise
to the university, which have been considerable and which will be used
as a foundation for the continuous improvement of quality. Also includes
a short discussion of the relationship between BS EN ISO 9001, HEFCE
quality assessment and HEQC quality audit.
ISO 9000 as a global educational accreditation structure
Authors: Peters John , Wills Gordon
Published: July 2002

Argues a market‐orientation for the ISO 9000 quality assurance standards. Discusses the experiences of the International Management Centres (IMC) in seeking and gaining certification to ISO 9002. Argues that policing educational process delivery ‐ the keeping of promises ‐ would be a more useful activity for governmental policy‐makers than the policing of educational content ‐ the nature of the promise. Summarises in brief the clauses of ISO 9002 as they apply to IMC. Concludes with recommendations to educational institution administrators and policy‐makers.
Quality assurance and student work experience
Authors: Leslie David
Published: July 2002

This article is based on the premise that owing to the substantial attention given to quality assurance and related initiatives in higher education in recent years, the management, and related practices involved, of student work experience will have improved. To investigate this hypothesis a comparative analysis of the findings of two major research projects, involving similar methods, into student work experience is undertaken. The two studies are discussed, criteria for comparative analysis are identified and key findings presented. This leads to the conclusion, that while there is evidence of substantial improvement in the probability of students gaining experience in the preparation of curricula vitae and of interview situations, little progress has been made in enhancing the realisation of the many other benefits attributable to student work experience. Recommendations to address the identified weaknesses in the system are proposed.
Using information technology at East Tennessee State University
Authors: Chenoweth John D. , Price Kellie
Published: July 2002

With the demand for technology‐literate graduates, East Tennessee State University in Johnson City, Tennessee, decided to modify its General Education Curriculum to include a “using information technology” component. This component requires students to be proficient in the use of information technology by the time they graduate. The requirement also allows students to gain this proficiency within their major fields of study. Provides information on ETSU’s computer‐related requirements for graduation.
Differential effects of occupation on Internet usage
Authors: Teo Thompson S.H.
Published: July 2002

Although there has been much publicity about the Internet, empirical research focusing on it is still relatively sparse. Most research on the Internet has been carried out in Europe or USA rather than Asia. This study examines the differential effects of occupation on Internet usage in an Asian country, namely, Singapore. Data were collected on Internet users via a questionnaire placed on the World Wide Web. From three main occupational groups (students, non‐IT personnel and IT personnel) 1,299 usable responses were obtained. Differential effects of occupation in terms of Internet usage patterns, tasks preferences and factors affecting an enjoyable Internet experience were examined.
Analysis of packaging and sealing techniques for microelectronic modules and recent advances
Authors: Khanna P.K. , Bhatnagar S.K. , Gust W.
Published: July 2002

A critical analysis of packaging and sealing methods for integrated circuits, hybrid microcircuits and multichip modules has been done. The best hermetic and high yield weld seal is examined along with other conventional seals like solder seal, frit seal and plastic seal with special emphasis on materials and processes involved in each case. An overview of emerging technology is also presented. A comparative analysis is made for selection of the right technology and material for a particular requirement.
General and Specific Traits of Personality and Their Relation to Sleep and Academic Performance
Authors: Gray Elizabeth K. , Watson David
Published: July 2002

ABSTRACT Few studies have examined the links between personality variables and sleep and their combined effect on specific real‐world outcomes. Participants in this study completed numerous personality, sleep, and performance measures; we examined the associations among these measures. Personality was assessed using the Five‐Factor Model. The personality trait of Conscientiousness (especially its facet of Achievement Striving) was a substantial predictor of academic performance. Analyses of the sleep variables revealed three distinct constructs: quantity, quality, and schedule. Sleep quantity showed few interesting correlates. In contrast, sleep quality was associated with greater well‐being and improved psychological functioning, whereas sleep schedule (i.e., average rising and retiring times) was significantly related to Conscientiousness, such that conscientious individuals maintain earlier schedules.
An Asymptotic Analysis of an Optimal Hedging Model for Option Pricing with Transaction Costs
Authors: Whalley A. E. , Wilmott P.
Published: July 2002

Davis, Panas, and Zariphopoulou (1993) and Hodges and Neuberger (1989) have presented a very appealing model for pricing European options in the presence of rehedging transaction costs. In their papers the ‘maximization of utility’ leads to a hedging strategy and an option value. The latter is different from the Black–Scholes fair value and is given by the solution of a three–dimensional free boundary problem. This problem is computationally very time–consuming. In this paper we analyze this problem in the realistic case of small transaction costs, applying simple ideas of asymptotic analysis. The problem is then reduced to an inhomogeneous diffusion equation in only two independent variables, the asset price and time. The advantages of this approach are to increase the speed at which the optimal hedging strategy is calculated and to add insight generally. Indeed, we find a very simple analytical expression for the hedging strategy involving the option's gamma.
Modulation of network behaviour by changes in variance in interneuronal properties
Authors: Aradi I. , Soltesz I.
Published: July 2002

Interneurones are important regulators of neuronal networks. The conventional approach to interneurones is to focus on the mean values of various parameters. Here we tested the hypothesis that changes in the variance of interneuronal properties (e.g. in the degree of scattering of parameter values of individual cells around the population mean) may modify the behaviour of networks. Biophysically based multicompartmental models of principal cells and interneurones showed that changes in the variance in the electrophysiological and anatomical properties of interneurones significantly alter the input‐output functions, rhythmicity and synchrony of principal cells, even if the mean values were unchanged. In most cases, increased heterogeneity in interneurones resulted in stronger inhibition of principal cell firing; however, there were parameter ranges where increased interneuronal variance decreased the inhibition of principal cells. Electrophysiological recordings showed that the variance in the resting membrane potential of CA1 stratum oriens interneurones persistently increased following experimental complex febrile seizures in developing rats, without a change in the mean resting membrane potential, indicating that lasting alterations in interneuronal heterogeneity can take place in real neuronal systems. These computational and experimental data demonstrate that modifications in interneuronal population variance influence the behaviour of neuronal networks, and suggest a physiological role for interneuronal diversity. Furthermore, the results indicate that interneuronal heterogeneity can change in neurological diseases, and raise the possibility that neuromodulators may act by regulating the variance of key parameters in interneuronal populations.
A Closed Form Solution for Flow During the Vacuum Assisted Resin Transfer Molding Process
Authors: Hsiao K-T. , Mathur R. , Advani S. G. , Gillespie, J. W. , Fink B. K.
Published: July 2002

A closed form solution to the flow of resin in vacuum assisted resin transfer molding process (VARTM) has been derived. VARTM is used extensively for affordable manufacturing of large composite structures. During the VARTM process, a highly permeable distribution medium is incorporated into the preform as a surface layer. During infusion, the resin flows preferentially across the surface and simultaneously through the preform giving rise to a complex flow front. The analytical solution presented here provides insight into the scaling laws governing fill times and resin inlet placement as a function of the properties of the preform, distribution media and resin. The formulation assumes that the flow is fully developed and is divided into two regimes: a saturated region with no crossflow and a flow front region where the resin is infiltrating into the preform from the distribution medium. The flow front region moves with a uniform velocity. The law of conservation of mass and Darcy’s Law for flow through porous media are applied in each region. The resulting equations are nondimensionalized and are solved to yield the flow front shape and the development of the saturated region. It is found that the flow front is parabolic in shape and the length of the saturated region is proportional to the square root of the time elapsed. The results thus obtained are compared to data from full scale simulations and an error analysis of the solution was carried out. It was found that the time to fill is determined with a high degree of accuracy while the error in estimating the flow front length, d, increases with a dimensionless parameter ε=K2xxh22/K2yyd2. The solution allows greater insight into the process physics, enables parametric and optimization studies and can reduce the computational cost of full-scale 3-dimensional simulations. A parametric study is conducted to establish the sensitivity of flow front velocity to the distribution media/preform thickness ratio and permeabilities and preform porosity. The results provide insight into the scaling laws for manufacturing of large scale structures by VARTM. [S1087-1357(00)02002-5]
Prediction of Ductile Fracture in Metal Blanking
Authors: Goijaerts A. M. , Govaert L. E. , Baaijens F. P. T.
Published: July 2002

This study is focused on the description of ductile fracture initiation, which is needed to predict product shapes in the blanking process. Two approaches are elaborated using a local ductile fracture model. According to literature, characterization of such a model should take place under loading conditions, comparable to the application. Therefore, the first approach incorporates the characterization of a ductile fracture model in a blanking experiment. The second approach is more favorable for industry. In this approach a tensile test is used to characterize the fracture model, instead of a complex and elaborate blanking experiment. Finite element simulations and blanking experiments are performed for five different clearances to validate both approaches. In conclusion it can be stated that for the investigated material, the first approach gives very good results within the experimental error. The second approach, the more favorable one for industry, yields results within 6 percent of the experiments over a wide, industrial range of clearances, when a newly proposed criterion is used. [S1087-1357(00)02202-4]
Visibility Analysis and Synthesis for Assembly Fixture Certification Using Theodolite Systems
Authors: Chen Hung-Kuei , Hu S. Jack , Woo T. C.
Published: July 2002

In automotive sheet metal assembly, part positioning and clamping is accomplished by fixtures consisting of fixture elements, such as pins and blocks. The locations of these elements are determined during process design and need to be certified during the construction and installation of an assembly line. Usually, theodolite systems are used to certify the locations of these elements by measuring the trihedron points on the fixture elements. However, no systematic method exists for the selection and placement of measuring systems. As a result, the current certification procedure is very time-consuming and is prone to error. This paper presents an algorithm for the optimal setup and placement of theodolite systems based on visibility analysis and synthesis. For a given tooling fixture, the visibility map is introduced to represent the set of potential measurement locations when a number of fixture elements are to be measured. From the set of potential measurement locations, an optimal setup will be selected based on minimizing the number of theodolite heads by optimally locating these theodolites. This approach will minimize measurement setups and improve measurement accuracy.
Numerical Prediction of Flow Fields Around Circular Cylinders: Forced Motion and Dynamic Response Cases
Authors: Lu S. , Turan O¨. F.
Published: July 2002

At Re=2000, the predicted flow field around a circular cylinder in forced transverse oscillation is verified with experimental results. For coupled torsional and transverse oscillation cases, the numerical results indicate that lock-in depends on the relative phase between torsional and translational oscillations. The dynamic response of an elastically mounted circular cylinder in cross flow, obtained by solving the structural equations simultaneously with the Navier-Stokes equations, is in reasonable agreement with experimental data. The dynamic response results indicate that the change of wake pattern from 2S to 2P with increased frequency ratio, is not always simultaneous with the change in the relative phase between lift force and cylinder displacement. [S0098-2202(00)02003-4]
Interlaminar Fracture Toughness of a Graphite/Epoxy Multidirectional Composite1
Authors: Yang Z. , Sun C. T.
Published: July 2002

In this paper, an experimental investigation on interlaminar fracture behavior and fracture toughness of a graphite/epoxy multidirectional composite laminate is presented using end-notched flexure specimens. The 0/θ interfaces are considered. The interlaminar fracture toughness is obtained and compared using three data reduction methods, i.e., the area method, classical laminated plate theory, and finite element analysis. Results show that the toughness value depends on the data reduction method used. Two different crack-length-to-span ratios are chosen to study how the stable or unstable crack extension influences the toughness measurement. It is observed that the toughness obtained from the tests of stable crack extension is appreciably higher than that from the tests of unstable crack extension. It is also seen that friction resulting from contact of crack surfaces greatly affects the measured toughness in the case of stable crack extension. In addition, effects of the specimen geometry and fiber orientation on the interlaminar fracture toughness are also evaluated. [S0094-4289(00)02804-8]
Development of a Functional Basis for Design
Authors: Stone Robert B. , Wood Kristin L.
Published: July 2002

Functional models represent a form independent blueprint of a product. As with any blueprint or schematic, a consistent language or coding system is required to ensure others can read it. This paper introduces such a design language, called a functional basis, where product function is characterized in a verb-object (function-flow) format. The set of functions and flows is intended to comprehensively describe the mechanical design space. Clear definitions are provided for each function and flow. The functional basis is compared to previous functional representations and is shown to subsume these attempts as well as offer a more consistent classification scheme. Applications to the areas of product architecture development, function structure generation, and design information archival and transmittal are discussed. [S1050-0472(00)00704-2]
Anti-Optimization Versus Probability in an Applied Mechanics Problem: Vector Uncertainty
Authors: Zingales M. , Elishakoff I.
Published: July 2002

In this study probabilistic and nonprobabilistic anti-optimization approaches are contrasted to evaluate their relative advantages and disadvantages while solving a mechanical problem in presence of vector uncertainty. The different cases that are analyzed in probabilistic setting that deal with either uniform or generic probability density functions for the uncertain variables varying in a rectangular domain. This case has been compared with interval analysis, a particular case of anti-optimization. The presence of a convex, smooth boundary of the uncertain domain has been also considered for comparing results obtained with these two alternative methods. It is shown that in case of vector uncertainty the anti-optimization method yields the same solution for the design problem as is provided by means of more complex probabilistic considerations. [S0021-8936(00)03103-2]
Partially Premixed Flame Structure and Stability of Twin Droplets in Flows
Authors: Chen W. H.
Published: July 2002

The flame structure and stability, as well as the vaporization rates of twin droplets exposed to a high-temperature, partially premixed flow are investigated in the present study. Two important parameters of the Reynolds number and ambient equivalence ratio are taken into consideration to account for the influence of fuel vapor in the upstream far field on those of burning mechanisms around the twin droplets. When increasing the ambient equivalence ratio, the chemical reactivity in the upstream can be classified into three types; weakly, moderately, and obviously reactive flows, according to the distribution of the vaporization rate of the leading droplet versus the Reynolds number. In particular, if the flow is moderately reactive, say, ϕ=0.2, a double-peak profile is observed in the vaporization rate of the leading droplet, and it clearly depicts that by increasing the Reynolds number the vaporization is sequentially dominated by the envelope flame, reactive flow, and convective flow. With regard to the trailing droplet, because of the multiple effects stemming from the leading droplet, the impact of the ambient equivalence ratio on the vaporization rate distribution is similar, except for in the purely oxidizing environment in which the twin droplets behave as a single droplet. As a whole, the evaluated results illustrate that the partially premixed flow is conducive to promoting the vaporization and aides the flame stability in a twin-droplet system, while some burning characteristics in a counterflow system can also be obtained in front of the leading droplet. [S0022-1481(00)01504-8]
Using Sweep and Dihedral to Control Three-Dimensional Flow in Transonic Stators of Axial Compressors
Authors: Gu¨mmer V. , Wenger U. , Kau, H.-P.
Published: July 2002

The paper describes an advanced three-dimensional blading concept for highly loaded transonic compressor stators. The concept takes advantage of the aerodynamic effects of sweep and dihedral. To the knowledge of the authors this is the first approach reported in the open literature that combines those two basic types of lean in an engine-worthy aerofoil design. The paper makes a contribution to the understanding of the endwall effect of both features with special emphasis put on sweep. The advanced three-dimensional blading concept was applied to an Engine Section Stator (ESS) of an aero-engine fan. In order to demonstrate how three-dimensional flow can be controlled, numerical analysis of the flow structure in a conventional and an advanced stator configuration was performed using a three-dimensional Navier–Stokes solver. The numerical analysis showed the advanced blade improving both radial loading distribution and the three-dimensional endwall boundary layer development. In particular, a strong hub corner stall could be largely alleviated. High-speed rig testing of the advanced ESS confirmed the concept and showed good qualitative agreement between measurement and prediction. The work presented was closely linked to the development of the BR710 engine on which the advanced ESS is in service today.
Stability of the Base Flow to Axisymmetric and Plane-Polar Disturbances in an Electrically Driven Flow Between Infinitely-Long, Concentric Cylinders
Authors: Liu J. , Talmage G. , Walker J. S.
Published: July 2002

The method of normal modes is used to examine the stability of an azimuthal base flow to both axisymmetric and plane-polar disturbances for an electrically conducting fluid confined between stationary, concentric, infinitely-long cylinders. An electric potential difference exists between the two cylinder walls and drives a radial electric current. Without a magnetic field, this flow remains stationary. However, if an axial magnetic field is applied, then the interaction between the radial electric current and the magnetic field gives rise to an azimuthal electromagnetic body force which drives an azimuthal velocity. Infinitesimal axisymmetric disturbances lead to an instability in the base flow. Infinitesimal plane-polar disturbances do not appear to destabilize the base flow until shear-flow transition to turbulence.
Elastic Fields in Double Inhomogeneity by the Equivalent Inclusion Method
Authors: Shodja H. M. , Sarvestani A. S.
Published: July 2002

Consider a double-inhomogeneity system whose microstructural configuration is composed of an ellipsoidal inhomogeneity of arbitrary elastic constants, size, and orientation encapsulated in another ellipsoidal inhomogeneity, which in turn is surrounded by an infinite medium. Each of these three constituents in general possesses elastic constants different from one another. The double-inhomogeneity system under consideration is subjected to far-field strain (stress). Using the equivalent inclusion method (EIM), the double inhomogeneity is replaced by an equivalent double-inclusion (EDI) problem with proper polynomial eigenstrains. The double inclusion is subsequently broken down to single-inclusion problems by means of superposition. The present theory is the first to obtain the actual distribution rather than the averages of the field quantities over the double inhomogeneity using Eshelby’s EIM. The present method is precise and is valid for thin as well as thick layers of coatings, and accommodates eccentric heterogeneity of arbitrary size and orientation. To establish the accuracy and robustness of the present method and for the sake of comparison, results on some of the previously reported problems, which are special cases encompassed by the present theory, will be re-examined. The formulations are easily extended to treat multi-inhomogeneity cases, where an inhomogeneity is surrounded by many layers of coatings. Employing an averaging scheme to the present theory, the average consistency conditions reported by Hori and Nemat-Nasser for the evaluation of average strains and stresses are recovered.
A New Calculation Method of Hertz Elliptical Contact Pressure
Authors: Tanaka Naoyuki
Published: July 2002

A new method for calculating elliptical Hertz contact pressure in which an elliptic integral is not necessary, has been developed. The simplest numerical integration by this method yields a Hertz contact pressure within 0.0005 percent of the theoretical spherical contact pressure. And dimensionless quantities, for calculating contact pressure, major and minor semi-axes and approach calculated by using the method agree well with those given in the references. Elliptical Hertz contact pressure can thus now be calculated by using a spreadsheet program for personal computers.
Interactive Multiobjective Optimization Design Strategy for Decision Based Design
Authors: Tappeta Ravindra V. , Renaud John E.
Published: July 2002

This research focuses on multi-objective system design and optimization. The primary goal is to develop and test a mathematically rigorous and efficient interactive multi-objective optimization algorithm that takes into account the Decision Maker’s (DM’s) preferences during the design process. An interactive MultiObjective Optimization Design Strategy (iMOODS) has been developed in this research to include the Pareto sensitivity analysis, Pareto surface approximation and local preference functions to capture the DM’s preferences in an Iterative Decision Making Strategy (IDMS). This new multiobjective optimization procedure provides the DM with a formal means for efficient design exploration around a given Pareto point. The use of local preference functions allows the iMOODS to construct the second order Pareto surface approximation more accurately in the preferred region of the Pareto surface. The iMOODS has been successfully applied to two test problems. The first problem consists of a set of simple analytical expressions for the objective and constraints. The second problem is the design and sizing of a high-performance and low-cost ten bar structure that has multiple objectives. The results indicate that the class functions are effective in capturing the local preferences of the DM. The Pareto designs that reflect the DM’s preferences can be efficiently generated within IDMS.
A Restudy of the Paradox on an Elastic Wedge Based on the Hamiltonian System
Authors: Yao and W. A. , Xu C.
Published: July 2002

In this paper, the paradox on the elastic wedge is restudied under the Hamiltonian system. This research shows that a special paradox in Euclidean space under the Lagrange system is just the Jordan form solutions in symplectic space under the Hamiltonian system, so they can be solved directly and rationally by normal mathematical physics methods.
Elastic Fields in a Polyhedral Inclusion With Uniform Eigenstrains and Related Problems
Authors: Nozaki H. , Taya M.
Published: July 2002

In this paper, the elastic field in an infinite elastic body containing a polyhedral inclusion with uniform eigenstrains is investigated. Exact solutions are obtained for the stress field in and around a fully general polyhedron, i.e., an arbitrary bounded region of three-dimensional space with a piecewise planner boundary. Numerical results are presented for the stress field and the strain energy for several major polyhedra and the effective stiffness of a composite with regular polyhedral inhomogeneities. It is found that the stresses at the center of a polyhedral inclusion with uniaxial eigenstrain do not coincide with those for a spherical inclusion (Eshelby’s solution) except for dodecahedron and icosahedron which belong to icosidodeca family, i.e., highly symmetrical structure.
Transport Phenomena of Developing Laminar Mixed Convection in Inclined Rectangular Ducts With Wall Transpiration
Authors: Yan Wei-Mon , Tzeng Pei-Yuan
Published: July 2002

A numerical calculation has been carried out to investigate the mixed convection heat transfer in inclined rectangular ducts with wall transpiration. The vorticity-velocity method is employed to solve the governing equations. The present paper particularly addresses the effects of the independent parameters, namely, mixed convection parameter Δ, modified Rayleigh number Ra*, wall Reynolds number Rew and aspect ratio γ. The predicted results show that either wall injection or wall suction has a considerable impact on the flow structure and heat transfer performance. Additionally, it was found that for injection case Rew<0, the Nusselt number Nu is retarded with an increase in the wall Reynolds number Rew, but the trend is reverse for the suction flow Rew>0.
Air Entrainment Versus Lubricant Vaporization in Squeeze Film Dampers: An Experimental Assessment of Their Fundamental Differences
Authors: Diaz S. E. , San Andre´s L. A.
Published: July 2002

Squeeze film dampers (SFDs) provide structural isolation and energy dissipation in air-breathing engines and process gas compressors. However, SFDs are prone to develop a flow regime where the ingestion of air leads to the formation of a bubbly lubricant. This pervasive phenomenon lacks proper physical understanding and sound analytical modeling, although actual practice demonstrates that it greatly reduces the damper force response. Measurements of film pressures in a test SFD describing circular centered orbits at whirl frequencies varying from 0 to 100 Hz are presented for fully flooded and vented discharge operating conditions. The experiments demonstrate that operation with low levels of external pressurization, moderate to large whirl frequencies, and lubricant discharge to ambient leads to the entrapment of air within the damper film lands. The experiments also elucidate fundamental differences in the generation of film pressures and forces for operation in a flooded condition that evidences vapor cavitation. Damping forces for the vented end with air entrainment are just 15 percent of the forces measured for the flooded damper. Further measurements at constant whirl frequencies demonstrate that increasing the lubricant pressure supply retards the onset of air entrainment. Classical fluid film cavitation models predict well the pressures and forces for the lubricant vapor cavitation condition. However, prevailing models fail to reproduce the dynamic forced response of vented (open-ended) SFDs where air entrainment makes a foamy lubricant, which limits severely the damper film pressures and forces.
Flow Investigation Around a V-Sector Ball Valve
Authors: Merati P. , Macelt M. J. , Erickson R. B.
Published: July 2002

Experimental and computational methods were used to study the structure and behavior of the shedded vortices around a V-ball valve. Strouhal frequency for shedded vortices around the valve over a range of operating conditions and flow rates using water as the medium were measured. The information gathered in this study would help to predict at what operating conditions pipe ruptures might occur. A dynamic pressure transducer was used to determine the Strouhal frequency. LDV was used to measure the mean velocity and turbulence magnitudes. FLUENT was used to develop a two dimensional fluid dynamics model. Flow was visualized using high-speed video photography. A dominant large three-dimensional vortex downstream of the valve was detected. The centerline of this vortex is a shadow of the valve lip. A fifth degree polynomial describing the relationship between the Strouhal number and Reynolds number is obtained.
Detailed Analysis of the Acoustic Mode Shapes of an Annular Combustion Chamber
Authors: Walz G. , Krebs W. , Hoffmann S. , Judith H.
Published: July 2002

To get a better understanding of the formation of thermoacoustic oscillations in an annular gas turbine combustor, an analysis of the acoustic eigenmodes has been conducted using the finite element method. The influence of different boundary conditions and a space-dependent velocity of sound has been investigated. The boundary conditions actually define the eigenfrequency spectrum. Hence, it is crucial to know, e.g., the burner impedance. In case of the combustion system without significant mixing air addition considered in this paper, the space-dependence of the velocity of sound is of minor importance for the eigenfrequency spectrum leading to a maximum deviation of only five percent in the eigenvalues. It is demonstrated that the efficiency of the numerical eigenvalue analysis can be improved by making use of symmetry, by splitting the problem into several steps with alternate boundary conditions, and by choosing the shift frequency ωs in the range of frequencies one is interested in.