bluuebunny/crossref_metadata_2025 huggingface dataset:
Leaders achieving focus in the place of not knowing
Authors: Simpson Peter , Burnard Hugh
Published: July 2002

The senior manager’s role is to constantly identify and clarify what to focus on and then to direct energy into that focus. This involves learning to gain clarity of purpose within a context of uncertainty and disagreement: the place of not knowing. Learning to work in this way involves discovering how to act as though one knows whilst still not knowing. This requires a working awareness of the fact that certainty is socially constructed knowing rather than discovered truth. In this way, leaders can lead others to know what to do. The authors present a case study of their work together (as an academic and a chief executive) which describes one approach to supporting organizational leaders in this task.
Using peer mentors during periods of uncertainty
Authors: Siegel Philip H.
Published: July 2002

This article shows how peer relationships in work settings can affect adjustments and personal and professional growth during stressful periods caused by mergers and acquisitions. After identifying subordinate, peer and mentoring relationships and demonstrating how individuals normally form such relationships at various career stages, the study finds that peer relationships may provide an antidote to stress at all professional levels. Moreover, accountants tend to favor the psycho‐social aspect of peer relationships during and after a merger.
Vision processing for robot learning
Authors: Nehmzow Ulrich
Published: July 2002

Robot learning ‐ be it unsupervised, supervised or self‐supervised ‐ is one method of dealing with noisy, inconsistent, or contradictory data that has proven useful in mobile robotics. In all but the simplest cases of robot learning, raw sensor data cannot be used directly as input to the learning process. Instead, some “meaningful” preprocessing has to be applied to the raw data, before the learning controller can use the sensory perceptions as input. In this paper, two instances of supervised and unsupervised robot learning experiments, using vision input are presented. The vision sensor signal preprocessing necessary to achieve successful learning is also discussed.
Commercial lease terms and the property cycle
Authors: Robinson Jon
Published: July 2002

The importance of taking corporate real estate decisions given a cyclical property market is discussed and illustrated. Ownership and leasing are described. Commercial lease terms are discussed in the context of the recent property cycle in Melbourne, Australia. A case study shows that the profitability of business units can be severely affected if the lease fundamentals, particularly the rent review mechanism, are misunderstood.
Quality management practices of ISO vs non‐ISO companies: a case of Indian industry
Authors: Gupta Atul
Published: July 2002

This empirical study is a first attempt to find the differences between ISO and non‐ISO organizations in India. Four areas of study include technology management, causes of poor quality, participation in the quality improvement programs and quality control techniques used. The results of this study indicate that statistically significant differences do exist between ISO and non‐ISO organizations under all the four categories specifically in training, using quality in the strategic planning, product design and team building.
Solution of coupled systems by distinct operators
Authors: St Doltsinis Ioannis
Published: July 2002

Addresses problems in mechanics and physics involving two or more coupled variables of different nature, or a number of distinct domains which interact. For these kinds of problems, considers numerical solution by the coupling of operators appertaining to the individual participating phenomena, or defined in the domains. Reviews the co‐operation of distinct discretized operators in connection with the integration of temporal evolution processes, and the iterative treatment of stationary equations of state. The specification of subtasks complies with the demand for an independent treatment on different processing units arising in parallel computation. Physical subtasks refer to problems of different field variables interacting on the continuum level; their number is usually small. Fine granularity may be achieved by separating the problem region into subdomains which communicate via the boundaries. In multiphysics simulations operators are preferably combined such that subdomains are processed in parallel on different units, while physical phenomena are processed sequentially in the subdomain.
Neumann expansion for fuzzy finite element analysis
Authors: Lallemand B. , Plessis G. , Tison T. , Level P.
Published: July 2002

This paper presents a new framework to predict a structure’s effective properties and sensitivities to multiple simultaneous uncertain endogenous parameters. The methodology is based on the use of fuzzy sets and this paper extends the fuzzy set theory to a dynamic finite element analysis of engineering systems containing uncertainty on material properties. A general algorithm, which can resolve the uncertain eigenvalue problem by using a Neumann expansion, is studied. This algorithm is applied to the study of the modal behavior of structures presenting uncertain material properties. Finally, the entropy and the specificity of fuzzy responses lead to the identification of a plate structure’s most sensitive eigenvalue to uncertain sources.
An integrated software environment for multi‐disciplinary computational engineering
Authors: Weatherill N.P. , Turner‐Smith E.A. , Jones J. , Morgan K. , Hassan O.
Published: July 2002

As computer simulation increasingly supports engineering design and manufacture, the requirement for a computer software environment providing an integration platform for computational engineering software increases. The potential benefits to industry are considerable. As a first step in the long‐term development of such a system, a computer software environment has been developed for pre‐ and post‐processing for unstructured grid‐based computational simulation. Arbitrary computer application software can be integrated into the environment to provide a multi‐disciplinary engineering analysis capability within one unified computational framework. Recognising the computational demands of many application areas, the environment includes a set of parallel tools to help the user maximise the potential of high performance computers and networks. The paper will present details of the environment and include an example of, and discussion about, the integration of application software.
Self‐serving biases: evidence from a simulated labour relationship
Authors: Charness Gary , Haruvy Ernan
Published: July 2002

A self‐serving bias occurs when people subconsciously alter their perceptions about what is fair or right in a manner that serves their own interests. Perceptions of what constitutes “fair performance” may well vary according to one’s role in the employment relationship. While it is clear that employee satisfaction affects job performance, and that wage affects employee satisfaction, it is not only wage per se that determines morale, but also the perceived fairness of the received wage. Evidence from a laboratory experiment indicates these views differ significantly between participant “employers” and “employees.” We compare choices (hypothetical in the case of employers) for the amount of costly “effort” to provide in response to a wage that has been determined outside the employment relationship. In the field, managers must be aware of the relationship between fairness in compensation and employee morale, as well as their own biases regarding the fairness reference point.
Residues in printed wiring boards and assemblies
Authors: Pauls Douglas
Published: July 2002

This paper is an examination of residues on printed wiring boards and printed wiring assemblies. Sources of residues are illustrated and the effects of various residues are discussed. Case studies are presented for bare board cleanliness issues, water soluble flux and aqueous cleaning processes, and low solids flux (no‐clean) processes, with and without cleaning. The case studies reflect lessons learned in various process troubleshooting efforts. Residues in this paper were characterized using advanced ion chromatography procedures. In addition, some data on surface insulation resistance (SIR) are presented.
Temperature cycling effects in some glob top polymer materials
Authors: Khoo C.G.L. , Liu Johan
Published: July 2002

Three common glob top encapsulant materials, two epoxy‐based, and one silicone‐based, were characterized prior to temperature cycling using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical spectroscopy (DMS), gas chromatograph‐mass spectrometry (GC‐MS), and Fourier transform infrared spectroscopy (FTIR). After cycling between ‐55 to +125°C, for 1,000 cycles, the same samples were again analysed using DMS and FTIR. For the epoxy‐based samples, the DMS results indicated that temperature cycling in a humid environment can seriously affect the physical and mechanical properties of these samples. FTIR data also indicated that the molecular changes in the epoxy‐based samples appeared quite extensive after cycling, indicating a high level of degradation on the molecular scale. On the other hand, the silicon‐based glob top appeared to have survived the temperature cycling quite well.
Semi‐autonomous study groups
Authors: Hogan Christine
Published: July 2002

Many innovations have taken place in the teaching‐learning strategies for organisational behaviour (OB), in the School of Management over the past 18 months. This paper describes the impetus for these changes (i.e. budget pressures) and the search for alternative teaching‐learning strategies suitable for organisational behaviour. It documents the journey of lecturers, part‐time staff and students who took part in this adventure. The change process involved a team of eight full‐time and ten part‐time staff members and over 800 students in a multicultural environment. During the first meeting, students had to negotiate their roles, desirable group norms and the gradations of penalties they would use if these ground rules were not adhered to. Each week the roles of facilitator, facilitator’s buddy, time‐keeper and scribe were rotated. Students learnt to work with “dominators”, “quiet members”, “social loafers”, “poor timekeepers”. Some learnt to confront conflict, others decided to ignore it. Student assignments included a creative learning log and a report describing in depth what they learnt themselves and working in groups and relating their experiences to models and theories of organisational behaviour.
Developing research capacity: the second step
Authors: Rowley Jennifer
Published: July 2002

This article suggests some strategies for the second stage of building research capacity. Research planning becomes a more central activity in this phase of development. Key issues for such planning are ownership, objectives, outcomes and organisation. Successful development depends both on effective team working and individual achievements. Research networking and quality are at the centre of individual strategies in this second phase of development. A model which identifies the different stages of research networking is offered; this may assist in mapping progress and establishing objectives of individual members of a team.
Team‐based sewn products manufacturing: a case study
Authors: Dillard Betty G.
Published: July 2002

Examines a team system using a case study approach in a sewn products plant that transitioned to the team system almost ten years ago. The theoretical framework utilized in the analysis of data was participative management, wherein it has been found that there is a relationship between employee knowledge and performance. Specific themes that arose were successes in the transition to the new team system, including benefits to the plant, and ongoing challenges of the new team system. Data were based on 16 in‐depth personal interviews, observations, written documents, and informal conversations with plant employees. The key elements of success in the transition were commitment by upper level managers, education for all employees, and the establishment of open communication among employees and with management. The team system resulted in a number of benefits and challenges to the plant as a whole.
Studies on handle of microdenier polyester filament dress materials
Authors: Behera B.K. , Chowdhry S. , Sobti M.
Published: July 2002

Polyester filament fabrics made from microdenier and normal denier yarn are compared for their low stress mechanical properties and hand values. Effects of twisting and sizing on microdenier filament fabric are studied. Sizing proves to be the most important process for microdenier multifilament yarn to realise its speciality effect in the fabric made out of this yarn.
Transient free convection past a semi‐infinite vertical plate with variable surface temperature
Authors: Takhar H.S. , Ganesan P. , Ekambavanan K. , Soundalgekar V.M.
Published: July 2002

Presents a finite‐difference solution to transient free convection flow past a semi‐infinite vertical plate in which the plate temperature T¢w(x) varies as the power of the axial co‐ordinate in the form T¢• + axn. Gives numerical results for fluids with Prandtl numbers Pr = 0.7 (air) and Pr = 7 (water) for three representative exponent values under non‐uniform surface heating conditions. Finds that the time to reach the steady‐state increases as the value of n or Pr increases. The steady‐state local skin‐friction falls by increasing the exponent n and Pr; however, the steady‐state local Nusselt number increases with n at a distance along the plate far away from the leading edge but decreases with increasing n near the leading edge of the plate. Also, the average Nusselt number increases and the average skin‐friction decreases as n increases because of enhanced heating of the plate.
Numerical simulation of a two‐phase dilute flow in a diffuser pipe
Authors: Daniel Eric , Loraud Jean‐Claude
Published: July 2002

A numerical simulation of a two‐phase dilute flow (droplet‐gas mixture) is carried out by using a finite volume method based on Riemann solvers. The computational domain represents a one‐ended pipe with holes at its upper wall which lead into an enclosure. The aim of this study is to determine the parameters of such a flow. More specially, an analytical solution is compared with numerical results to assess the mass flow rates through the vents in the pipe. Inertia effects dominate the dynamic behaviour of droplets, which causes a non‐homogeneous flow in the cavity. The unsteady effects are also important, which makes isentropical calculation irrelevant and shows the necessity of the use of CFD tools to predict such flows. No relation can be extracted from the numerical results between the gas and the dispersed mass flow rates across the holes. But a linear variation law for the droplet mass flow versus the position of the holes is pointed out, which is independent of the incoming flow when the evaporating effects are quite low.
Solution of temperature field in DC cast aluminium alloy billet by the dual reciprocity boundary element method
Authors: Sarler Bozidar , Mencinger Jure
Published: July 2002

The axisymmetric steady‐state convective‐diffusive thermal field problem associated with direct‐chill, semi‐continuously cast billets has been solved using the dual reciprocity boundary element method. The solution is based on a formulation which incorporates the one‐phase physical model, Laplace equation fundamental solution weighting, and scaled augmented thin plate splines for transforming the domain integrals into a finite series of boundary integrals. Realistic non‐linear boundary conditions and temperature variation of all material properties are included. The solution is verified by comparison with the results of the classical finite volume method. Results for a 0.500[m] diameter Al 4.5 per cent Cu alloy billet at typical casting conditions are given.
Strategic management of electronic commerce: an adaptation of the balanced scorecard
Authors: Hasan Helen , Tibbits Hendrika (Rita)
Published: July 2002

The balanced scorecard is a formal management technique that is built on the premise that measurement is a prerequisite to strategic management. A broad range of business goals can be incorporated in the scorecard and realistic performance targets can be aligned with business strategies. Electronic commerce is rapidly becoming concerned with the many different ways organisations do business and is therefore an area of strategic concern to organisations. A case study of the implementation of the balanced scorecard in a public utility will be analysed to suggest how the basic concepts and philosophy of the balanced scorecard can be retained in its adaptation to the strategic management of electronic commerce.
Unfolding mechanics of holo‐ and apocalmodulin studied by the atomic force microscope
Authors: Hertadi Rukman , Ikai Atsushi
Published: July 2002

The structural stability of calmodulin (CaM) has been investigated previously by chemical and thermal methods. The calcium‐loaded form of CaM has been found to be exceptionally stable, because it can be exposed to temperatures >90°C or to a 9 M urea solution without a marked change in its tertiary structure, and is therefore not experimentally accessible for unfolding studies using conventional analytical methods. In this study, we have developed a system for measuring the force for mechanically unfolding CaM using an atomic force microscope (AFM) by stretching the protein from its N‐ and C‐terminal residues; we have been successful in obtaining force versus extension (F–E) curves for both apo and holo forms of CaM. In our experiment, distinguishable F–E curves have been obtained upon stretching of apoCaM and holoCaM to their full extensions. A very low force observed upon stretching of apoCaM indicated a relatively high flexibility of the apo form. On the contrary, a relatively high unfolding force and the appearance of a characteristic force peak were noted during full stretching of holoCaM. The F–E curve of the latter form of CaM most likely reflects a more rigid and probably more organized conformation of holoCaM than that of apoCaM. These experiments confirmed that the AFM is able to clearly distinguish two functionally distinct forms of CaM in terms of their mechanical properties.
Structural changes and molecular interactions of hydrophobin SC3 in solution and on a hydrophobic surface
Authors: Wang X. , Vocht M.L.De , Jonge J.De , Poolman B. , Robillard G.T.
Published: July 2002

The hydrophobin SC3 belongs to a class of small proteins functioning in the growth and development of fungi. Its unique amphipathic property and remarkable surface activity make it interesting not only for biological studies but also for medical and industrial applications. Biophysical studies have revealed that SC3 possesses at least three distinct conformations, named “soluble‐state SC3” for the protein in solution, and “α‐helical‐state SC3” and “β‐sheet‐state SC3” for the different states of the protein associated at a hydrophobic‐water interface. The present fluorescence study shows that the microenvironment of the dansyl‐labeled N terminus of soluble‐state SC3 is relatively hydrophobic, whereas it is hydrophilic for α‐helical‐state and β‐sheet‐state SC3. Fluorescence collisional quenching indicates that the N terminus of soluble‐state SC3 is more solvent‐accessible than those of α‐helical‐state and β‐sheet‐state SC3, with Stern‐Volmer constants for acrylamide of 4.63, 0.02, and 0.2 M−1 for the different states, respectively. Fluorescence resonance energy transfer measurements show that soluble‐state SC3 tends to associate in solution but dissociates in TFA. Fluorescence energy transfer was eliminated by conversion of soluble‐state SC3 to α‐helical‐state SC3 on a hydrophobic surface, indicating a spatial separation of the molecules in this state. By inducing the β‐sheet state, structural changes were observed, both by CD and by fluorescence, that could be fit to two exponentials with lifetimes of about 10 min and 4 h. Molecules in the β‐sheet state also underwent a slow change in spatial proximity on the hydrophobic surface, as revealed by the reappearance of fluorescence resonance energy transfer in time.
Cavities of α1‐antitrypsin that play structural and functional roles
Authors: Lee Cheolju , Maeng Jin‐Soo , Kocher Jean‐Pierre , Lee Byungkook , Yu Myeong‐Hee
Published: July 2002

The native form of inhibitory serine protease inhibitors (serpins) is strained, which is critical for their inhibitory activity. Previous studies on stabilizing mutations of α1‐antitrypsin, a prototype of serpins, indicated that cavities provide a structural basis for the native strain of the molecule. We have systematically mapped the cavities of α1‐antitrypsin that play such structural and functional roles by designing cavity‐filling mutations at residues that line the walls of the cavities. Results show that energetically unfavorable cavities are distributed throughout the α1‐antitrypsin molecule, and the cavity‐filling mutations stabilized the native conformation at 8 out of 10 target sites. The stabilization effect of the individual cavity‐filling mutations of α1‐antitrypsin varied (0.2–1.9 kcal/mol for each additional methylene group) and appeared to depend largely on the structural flexibility of the cavity environment. Cavity‐filling mutations that decreased inhibitory activity of α1‐antitrypsin were localized in the loop regions that interact with β‐sheet A distal from the reactive center loop. The results are consistent with the notion that β‐sheet A and the structure around it mobilize when α1‐antitrypsin forms a complex with a target protease.
Differences in Automatic Social Information Processing Between Nondepressed and Subclinically Depressed Individuals
Authors: Cheng Cecilia , Chiu Chi‐yue
Published: July 2002

ABSTRACT The present research examined individual differences in automatic social information processing. We hypothesized that because nondepressed and subclinically depressed persons have different interpersonal experiences, they may process social information in different ways. In this experiment, participants were asked to make judgments about social relationships after being reminded of a target person. They had to make these judgments under either a light or a heavy memory load. Results showed that when nondepressed participants were reminded of people with whom they had frequent pleasant interactions, they made a greater number of positive judgments about their social relationships than did subclinically depressed participants. When subclinically depressed participants were reminded of people with whom they had had frequent unpleasant interactions, they made a greater number of negative judgments about their social relationships than did their nondepressed counterparts. Moreover, performance in these experimental conditions was unaffected by memory load, suggesting that automatic thoughts about their social relationships had been evoked.
Remodelling inactivation gating of Kv4 channels by KChIP1, a small‐molecular‐weight calcium‐binding protein
Authors: Beck Edward J. , Bowlby Mark , An W. Frank , Rhodes Kenneth J. , Covarrubias Manuel
Published: July 2002

Calcium‐binding proteins dubbed KChIPs favour surface expression and modulate inactivation gating of neuronal and cardiac A‐type Kv4 channels. To investigate their mechanism of action, Kv4.1 or Kv4.3 were expressed in Xenopus laevis oocytes, either alone or together with KChIP1, and the K+ currents were recorded using the whole‐oocyte voltage‐clamp and patch‐clamp methods. KChIP1 similarly remodels gating of both channels. At positive voltages, KChIP1 slows the early phase of the development of macroscopic inactivation. By contrast, the late phase is accelerated, which allows complete inactivation in < 500 ms. Thus, superimposed traces from control and KChIP1‐remodelled currents crossover. KChIP1 also accelerates closed‐state inactivation and recovery from inactivation (3‐ to 5‐fold change). The latter effect is dominating and, consequently, the prepulse inactivation curves exhibit depolarizing shifts (ΔV= 4–12 mV). More favourable closed‐state inactivation may also contribute to the overall faster inactivation at positive voltages because Kv4 channels significantly inactivate from the preopen closed state. KChIP1 favours this pathway further by accelerating channel closing. The peak G‐V curves are modestly leftward shifted in the presence of KChIP1, but the apparent ‘threshold’ voltage of current activation remains unaltered. Single Kv4.1 channels exhibited multiple conductance levels that ranged between 1.8 and 5.6 pS in the absence of KChIP1 and between 1.9 and 5.3 pS in its presence. Thus, changes in unitary conductance do not contribute to current upregulation by KChIP1. An allosteric kinetic model explains the kinetic changes by assuming that KChIP1 mainly impairs open‐state inactivation, favours channel closing and lowers the energy barrier of closed‐state inactivation.
pH and rate of ‘dark’ events in toad retinal rods: test of a hypothesis on the molecular origin of photoreceptor noise
Authors: Firsov Mikhail L. , Donner Kristian , Govardovskii Victor I.
Published: July 2002

Thermal activation of the visual pigment constitutes a fundamental constraint on visual sensitivity. Its electrical correlate in the membrane current of dark‐adapted rods are randomly occurring discrete ‘dark events’ indistinguishable from responses to single photons. It has been proposed that thermal activation occurs in a small subpopulation of rhodopsin molecules where the Schiff base linking the chromophore to the protein part is unprotonated. On this hypothesis, rates of thermal activation should increase strongly with rising pH. The hypothesis has been tested by measuring the effect of pH changes on the frequency of discrete dark events in red rods of the common toad Bufo bufo. Dark noise was recorded from isolated rods using the suction pipette technique. Changes in cytoplasmic pH upon manipulations of extracellular pH were quantified by measuring, using fast single‐cell microspectrophotometry, the pH‐dependent metarhodopsin I‐metarhodopsin II equilibrium and subsequent metarhodopsin III formation. These measurements show that, in the conditions of the electrophysiological experiments, changing perfusion pH from 6.5 to 9.3 resulted in a cytoplasmic pH shift from 7.6 to 8.5 that was readily sensed by the rhodopsin. This shift, which implies an 8‐fold decrease in cytoplasmic [H+], did not increase the rate of dark events. The results contradict the hypothesis that thermal pigment activation depends on prior deprotonation of the Schiff base.
Spontaneous electrical activity and associated changes in calcium concentration in guinea‐pig gastric smooth muscle
Authors: Fukuta Hiroyasu , Kito Yoshihiko , Suzuki Hikaru
Published: July 2002

Spontaneous electrical activity and internal Ca2+ concentration ([Ca2+]i) were measured simultaneously using conventional microelectrodes and fura‐2 fluorescence, respectively, in isolated circular smooth muscle bundles of the guinea‐pig gastric antrum. The smooth muscle bundles generated periodic slow potentials with accompanying spike potentials and associated transient increases in [Ca2+]i (Ca2+‐transients). Nifedipine abolished the spike potentials but not the slow potentials, and reduced the amplitude of associated Ca2+‐transients. Caffeine, in the absence or presence of ryanodine, reduced resting [Ca2+]i levels and abolished the slow potentials and associated Ca2+‐transients. Depolarization elevated and hyperpolarization reduced resting [Ca2+]i levels with associated changes in the frequency of slow potentials. The amplitude of Ca2+‐transients changed in a bell‐shaped manner with the membrane potential change. Slow potentials and associated Ca2+‐transients were abolished if [Ca2+]i levels were reduced by BAPTA‐AM or if the internal Ca2+ pump was inhibited by cyclopiazonic acid. 2‐Aminoethoxy‐diphenylborate (2‐APB), a known inhibitor of inositol trisphosphate (IP3)‐mediated Ca2+ release, also blocked slow potentials and Ca2+‐transients. Carbonyl cyanide m‐chlorophenyl hydrazone (CCCP), a mitochondrial protonophore, depolarized the membrane, elevated [Ca2+]i levels and abolished slow potentials and Ca2+‐transients. Inhibition of mitochondrial ATP‐sensitive K+ channels by glybenclamide and 5‐hydroxydecanoic acid (5‐HAD) abolished slow potentials and Ca2+‐transients, without altering the smooth muscle [Ca2+]i. It is concluded that in antrum circular muscles, the frequency of slow potentials is correlated with the level of [Ca2+]i. The slow potential is coupled to release of Ca2+ from an internal store, possibly through the activation of IP3 receptors; this may be initiated by the activation of ATP‐sensitive K+ channels in mitochondria following Ca2+ handling by mitochondria.
Evidence that ventilatory rhythmogenesis in the frog involves two distinct neuronal oscillators
Authors: Wilson R. J. A. , Vasilakos K. , Harris M. B. , Straus C. , Remmers J. E.
Published: July 2002

In Rana catesbeiana the upper airways are used for two distinct yet highly coordinated ventilatory behaviours: buccal ventilation and lung inflation cycles. How these behaviours are generated and coordinated is unknown. The purpose of this study was to identify putative rhythmogenic brainstem loci involved in these ventilatory behaviours. We surveyed the isolated postmetamorphic brainstem to determine sites where local depolarization, produced by microinjecting the non‐NMDA glutamate receptor agonist, AMPA, augmented the ventilatory motor patterns. Two sites were identified: a caudal site, at the level of cranial nerve (CN) X, where AMPA injections caused increased buccal burst frequency but abolished lung bursts, and a rostral site, between the levels of CN VIII and IX, where injections increased the frequency of both types of ventilatory bursts. These two sites were further examined using GABA microinjections to locally inhibit cells. GABA injected into the caudal site suppressed the buccal rhythm but the lung rhythm continued, albeit at a different frequency. When GABA was injected into the rostral site the lung bursts were abolished but the buccal rhythm continued. When the two sites were physically separated by transection, both rostral and caudal brainstem sections were capable of rhythmogenesis. The results suggest the respiratory network within the amphibian brainstem is composed of at least two distinct but interacting oscillators, the buccal and lung oscillators. These putative oscillators may provide a promising experimental model for studying coupled oscillators in vertebrates.
Deformation of Plasma Sprayed Thermal Barrier Coatings
Authors: Senturk Ufuk , Lima Rogerio S. , Lima Carlos R. C. , Berndt Christopher C.
Published: July 2002

The deformation behavior of thermally sprayed partially stabilized zirconia (PSZ) coatings are investigated using Hertzian indentation and four-point bend testing, with in situ acoustic emission monitoring. The experimental deformation curves, together with the corresponding acoustic emission responses and the fracture properties of the material are used in defining the deformation characteristics of the coating (ceramic overlay with metallic bond coat where applicable) and substrate composite system. Experiments are aimed in examining the influence of the bond coat and the coating properties on the form of deformation. Substrate temperature and pauses during spraying are demonstrated to strongly effect the coating properties and the resulting fracture/failure characteristics of the composite system. [S0742-4795(00)02503-5]
A Closed Shell Structured Eyeball Model With Application to Radial Keratotomy
Authors: Yeh Hsien-Liang , Huang Tseng , Schachar Ronald A.
Published: July 2002

A closed shell structured eyeball model was developed for predicting the displacements and curvatures in an eyeball due to radial keratotomy. Both the cornea and sclera are modeled as an ellipsoidal cap, and the two caps are connected at the limbus to form a closed shell. The analysis of the number of corneal collagen laminae required for the tissue to be theoretically transversely isotropic was presented. The cornea, as well as the limbus and sclera, is considered as macroscopically homogeneous and isotropic in this study. A procedure to obtain the principal curvature at a point on the exterior surface was established. In the basic formulation, large displacements are contemplated. However, the FORTRAN computer program that was prepared to implement the procedure considers small displacements, and the resulting equations are linear. Although the results from this shell structured eyeball model are fairly good quantitatively, they do show vividly the following qualitative corneal behavior after the operation is performed: The opening of an incision has a V-shape, the radial displacements through the corneal thickness are nearly the same, and the largest in-plane displacement is only one-tenth of the largest radial displacement. [S0148-0731(00)00705-6]
On the Development and Application of the Fast-Response Aerodynamic Probe System in Turbomachines—Part 2: Flow, Surge, and Stall in a Centrifugal Compressor
Authors: Roduner Christian , Kupferschmied Peter , Ko¨ppel Pascal , Gyarmathy Georg
Published: July 2002

The present paper, Part 2 of a trilogy, is primarily focussed on demonstrating the capabilities of a fast-response aerodynamic probe system configuration based on the simplest type of fast-response probe. A single cylindrical probe equipped with a single pressure sensor is used to measure absolute pressure and both velocity components in an essentially two-dimensional flow field. The probe is used in the pseudo-three-sensor mode (see Part 1). It is demonstrated that such a one-sensor probe is able to measure high-frequency rotor-governed systematic fluctuations (like blade-to-blade phenomena) alone or in combination with flow-governed low-frequency fluctuations as rotating stall (RS) and mild surge (MS). However, three-sensor probes would be needed to measure stochastic (turbulence-related) or other aperiodic velocity transients. The data shown refer to the impeller exit and the vaned diffuser of a single-stage high-subsonic centrifugal compressor. Wall-to-wall probe traverses were performed at the impeller exit and different positions along the vaned diffuser for different running conditions. The centrifugal compressor was operated under stable as well as unstable (pulsating or stalled) running conditions. The turbomachinery-oriented interpretation of these unsteady flow data is a second focus of the paper. A refined analysis of the time-resolved data will be performed in Part 3, where different spatial/temporal averaging methods are compared. Two different averaging methods were used for the data evaluation: impeller-based ensemble-averaging for blade-to-blade systematic fluctuations (with constant period length at a constant shaft speed), and flow-based class averaging for the relatively slow MS and RS with slightly variable period length. Due to the ability of fast-response probes to simultaneously measure velocity components and total and static pressure, interesting insights can be obtained into impeller and diffuser channel flow structures as well as into the time behavior of such large-domain phenomena as RS and MS. [S0889-504X(00)01103-X]
A Dual-Phase-Lag Diffusion Model for Predicting Intermetallic Compound Layer Growth in Solder Joints
Authors: Chen J. K. , Beraun J. E. , Tzou D. Y.
Published: July 2002

A dual-phase-lag diffusion (DPLD) model is presented for predicting the intermetallic compound (IMC) layer growth in solder joints. It extends from Fick’s law by taking into account the delayed response between the interdiffusion of two dissimilar materials and the chemical reaction that forms the IMC. The merit of this model is that it uniquely represents four different types of IMC growth kinetics, all of which are found in the literature. Comparison between the model and experimental results for 100Sn/Cu and Ag/Zn systems demonstrates that the proposed DPLD model captures the growth history of IMC layers quite well.
Heat Transfer in a Radially Rotating Four-Pass Serpentine Channel With Staggered Half-V Rib Turbulators
Authors: Hwang G. J. , Tzeng S. C. , Mao C. P. , Soong C. Y.
Published: July 2002

The present work is concerned with experimental investigation of the convective heat transfer in a radially rotating four-pass serpentine channel. Two types of staggered half-V rib turbulators are considered to examine their effects on heat transfer enhancement. The coolant air is pressurized and pre-cooled to compensate for the low rotating rate and low temperature or density difference in key parameters of thermal and flow characteristics. The geometric dimensions are fixed, whereas the ranges of the thermal and flow parameters in the present measurements are 20,000⩽Re⩽40,000,0⩽Ro⩽0.21, and Gr/Re2∼O10−2. The present results disclose the effects of the pressurized flow, rib arrangement, channel rotation, and centrifugal buoyancy on the local heat transfer in each passage of the channel. Finally, the present data are fitted on correlation equations for evaluation of local heat transfer in the rotating four-pass ribbed channel configurations considered.
Elevated-Temperature Mechanical Properties of an Advanced-Type 316 Stainless Steel1
Authors: Brinkman Charles R.
Published: July 2002

Type 316FR stainless steel is a candidate material for the Japanese demonstration fast breeder reactor plant to be built in Japan early in the next century. Like type 316L(N), it is a low-carbon grade of stainless steel with a more closely specified nitrogen content and chemistry optimized to enhance elevated-temperature performance. Early in 1994, under sponsorship of The Japan Atomic Power Company, work was initiated at Oak Ridge National Laboratory (ORNL) aimed at obtaining an elevated-temperature mechanical-properties database on a single heat of this material. The product form was 50-mm plate manufactured by the Nippon Steel Corporation. Data include results from long-term creep-rupture tests conducted at temperatures of 500 to 600°C with test times up to nearly 40.000 h, continuous-cycle strain-controlled fatigue test results over the same temperature range, limited creep-fatigue data at 550 and 600°C, and tensile test properties from room temperature to 650°C. The ORNL data were compared with data obtained from several different heats and product forms of this material obtained at Japanese laboratories. The data were also compared with results from predictive equations developed for this material and with data available for types 316 and 316L(N) stainless steel.
Stability Analysis of Large-Scale Time-Delay Systems Via Evolutionary Programming Algorithm
Authors: Yan Jun-Juh , Tsai and Jason Sheng-Hong , Sheen Ing Eh
Published: July 2002

A sufficient condition for delay-independent asymptotic stability of large-scale time-delay systems is derived. An evolutionary programming approach is newly developed to decompose the system matrix such that our result can be further improved. For testing the system stability, we do not attempt to solve the Lyapunov or Riccati equation, but need only to check the eigenvalues of a Hamiltonian matrix to guarantee the solvability of an algebraic Riccati equation. The present method is simple and less conservative than those proposed in the literature.
Time-Resolved Thermal Boundary-Layer Structure in a Pulsatile Reversing Channel Flow
Authors: Kearney Sean P. , Jacobi Anthony M. , Lucht Robert P.
Published: July 2002

In this paper, the results of an experimental study of the time-resolved structure of a thermal boundary layer in a pulsating channel flow are presented. The developing laminar regime is investigated. Two techniques were used for time-resolved temperature measurements: a nonintrusive, pure-rotational CARS method and cold-wire anemometry. Results are presented for differing degrees of flow reversal, and the data show that the primary impact of reversed flow is an increase in the instantaneous thermal boundary-layer thickness and a period of decreased instantaneous Nusselt number. For the developing laminar parameter space spanned by the experiments, time-averaged heat-transfer enhancements as high as a factor of two relative to steady flow are observed for nonreversing and partially reversed pulsating flows. It is concluded that reversal is not necessarily a requirement for enhancement.
The Phenomenon of Steady-State String Motion
Authors: Miroshnik R.
Published: July 2002

The paper examines the phenomenon of steady-state motion for a string traveling with constant velocity along an invariant curve under gravity in a viscous medium. This technically important phenomenon has been known in the literature for about 120 years and may be applied in high-speed turbines, the textile industry, etc. The conditions for the phenomenon’s existence are found. Concepts of two critical string velocities as well as sub, super, and hypercritical domains are introduced. The analytical solutions for the nonlinear differential equations and arbitrary constants for the general boundary conditions are found. The theoretical results are very close to the experimental ones.
An Approach to Capturing Structure, Behavior, and Function of Artifacts in Computer-Aided Design
Authors: Anthony Lisa , Regli William C. , John Jon E. , Lombeyda Santiago V.
Published: July 2002

This paper presents an approach to computer-aided design (CAD) that unites ideas from design with three-dimensional layouts and knowledge engineering. Our goal is to capture the structure, behavior, and function of CAD artifacts. We describe a software tool based on this approach, the conceptual understanding and prototyping (CUP) environment, for capturing the design intent inherent in the design process and authoring design semantics in previously created artifacts. CUP records design ideas, based on functional, geometric, and knowledge-based relationships among components in an electromechanical assembly. This design knowledge is stored using ontologies defined in the XML. The goal of this work is to enable users to navigate intricate product data and design knowledge bases.
Fully-Developed Laminar Flow in Sinusoidal Grooves
Authors: Thomas Scott K. , Lykins Richard C. , Yerkes Kirk L.
Published: July 2002

The flow of a constant property fluid through a sinusoidal groove has been analyzed. A numerical solution of the conservation of mass and momentum equations for fully developed flow is presented. The mean velocity, volumetric flow rate, and Poiseuille number are presented as functions of the groove geometry, meniscus contact angle, and shear stress at the liquid-vapor interface. In addition, a semi-analytical solution for the normalized mean velocity in terms of the normalized shear stress at the meniscus is shown to agree with the numerical data quite well.
Characterization of Particulate From Fires Burning Silicone Fluids
Authors: Sivathanu Yudaya , Hamins Anthony , Mulholland George , Kashiwagi Takashi , Buch Robert
Published: July 2002

The optical properties of particulate emitted from fires burning two distinct polydimethylsiloxane fluids (D4 and M2 or MM, where D=CH32SiO and M=CH33SiO2) were obtained using a transmission cell-reciprocal nephelometer in conjunction with gravimetric sampling. The specific absorption coefficient of particulate ash from fires burning D4 and MM is significantly lower than that of particulate soot from an acetylene (hydrocarbon) flame. Scattering is the dominant part of extinction in fires burning the silicone fluids. This is very different from extinction by soot particles in hydrocarbon fires, where absorption is approximately five times greater than scattering. Temperatures and particulate volume fractions along the axis of a silicone fire D4 were measured using multi-wavelength absorption/emission spectroscopy. The structure of the D4 flames is markedly different from hydrocarbon flames. The temperatures and particulate volume fractions very close to the burner surface are much higher than in comparably sized hydrocarbon flames.
Acoustic Fatigue of a Steam Dump Pipe System Excited by Valve Noise
Authors: Michaud Suzanne , Ziada Samir , Pastorel Henri
Published: July 2002

The steam dump system in Gentilly Nuclear Power Plant consists of four parallel steam pipes, each of which comprises a steam control valve. Two pipes of this system experienced high-cycle fatigue damage. In-situ vibration and dynamic strain measurements were therefore conducted to identify the cause of the damage and formulate suitable counter-measures. The test results pointed to the high-frequency noise of the valve as the primary source causing the fatigue failure. By means of small-scale model tests, using a compressed air network, a new valve stem was developed, which produces a substantially lower noise level than that generated by the original valve stem. Implementing this new stem in the plant, without any other modifications in the valve body or the piping system, significantly reduced the dynamic stresses of the piping, but increased the vibration level of the valve itself. An alternative valve stem, which is a simpler version of the new design, was therefore tested and found to reduce the pipe stresses sufficiently while not increasing the level of valve vibration.
Torsion of a Circular Compound Bar With Imperfect Interface
Authors: Chen T. , Weng I. S.
Published: July 2002

The Saint-Venant torsion problem of a circular cylinder reinforced by a nonconcentric circular bar of a different material with an imperfect interface is studied. Conformal mapping together with a Laurent series expansion are employed to analyze the problem. The jump condition in either the warping function or the shear traction, characterizing the imperfect interface, is simulated in the transformed domain in an exact manner. Unlike the problem with perfectly bonded interface, the series solution has to be resolved by a truncation. Numerical illustrations are provided for the torsional rigidity of the cross section. In the case of perfect bonding case, our results agree with that reported in Muskhelishvili.
Modeling Modulus Reduction in Bovine Trabecular Bone Damaged in Compression
Authors: Moore T. L. Arthur , Gibson L. J.
Published: July 2002

Loading bone beyond its yield point creates microdamage, leading to reduction in stiffness. Previously, we related microdamage accumulation to changes in mechanical properties. Here, we develop a model that predicts stiffness loss based on the presence of microdamage. Modeling is done at three levels: (1) a single trabecula, (2) a cellular solid consisting of intact, damaged, and fractured trabeculae, and (3) a specimen with a localized damage band. Predictions of a reduced modulus agree well with experimental measured modulus reductions of post-yield compression of bovine trabecular bone. The predicted reduced modulus is relatively insensitive to changes in the input parameters.
Correlations of Critical Froude Number for Annular-Rimming Flow in Rotating Heat Pipes
Authors: Baker J. , Oliver T. , Lin L. , Ponnapan R. , Leland J.
Published: July 2002

The behavior of flow within a rotating finite length cylinder has been investigated. For low rotational speeds, the flow is characterized by a non-uniform thickness i.e., rimming flow. Above a critical rotational speed, the flow transitions to annular flow. Correlations developed from the experimental data are presented for the three regimes: onset of annular flow, complete annular flow, and collapse of annular flow. The correlation for the collapse of annular flow compared well with a previously presented, theoretically developed correlation. Given that the heat transfer characteristics of rotating heat pipes depend upon the film thickness of the fluid charge, the correlations presented here will be valuable in determining regular operating conditions.