bluuebunny/crossref_metadata_2025 huggingface dataset:
Management training of professional engineers in New Zealand
Authors: Batley Tom
Published: July 2002

The need for management training for experienced professional engineers in New Zealand has been well recognised for a long time. Research with professional engineers in New Zealand, including a training needs analysis, has indicated a strong need and high potential benefits from management training, particularly in personal and interpersonal management skills. A list of 25 most appropriate personal and interpersonal skills was developed. A three‐day management training workshop was developed as a result of the research for engineers working in small groups. A book on management skills for professionals was written to reinforce the teaching. The course has since been run several times per year at the University of Canterbury and has attracted large numbers of engineers. Feedback from the course participants has been very positive, saying that it provides much needed opportunities for self‐development and learning.
Development of wood adhesives using flavonoid‐glycosides from orange mesocarp
Authors: Akaranta O. , Wankasi D.
Published: July 2002

Condensation products of orange mesocarp extract (flavonoid‐glycosides) and formaldehyde were modified with phenol, cashewnut shell liquid and resorcinol respectively. The copolymer resins formed were used in the formulation of wood adhesives. The glued veneers were evaluated for their shear strength and percentage wood failure assessed. The results showed that the adhesives cured to give gluelines of considerable strength and durability.
Educating students with disabilities in the least restrictive environment
Authors: Daniel Philip T.K.
Published: July 2002

States that historically, students with disabilities in the public schools in the USA were subjected to discrimination in the form of segregation from non‐disabled students. Also reports that much of this discrimination has subsided in recent years owing to successful advocacy by parents and community organizations before the Congress of the United States and both the federal and state judiciary. Reveals that national legislation was created so as to protect the education rights of such students and the courts have provided tests for their integration into school systems. Notes that, currently, there is some concern that this advocacy has gone too far and that court decisions authorizing “full inclusion” misinterpret the full extent of the law. Examines the scope of education for disabled children and provides a legal analysis of the educational placement of students with disabilities in the “least restrictive environment”.
Numerical study on laminar flow forced‐convection heat transfer for air in a channel with offset plates heated by radiation heat flux
Authors: Hamza H. Ali Ahmed , Kishinami Koki , Hanaoka Yutaka , Suzuki Jun
Published: July 2002

A two‐dimensional numerical study was carried out to investigate laminar forced‐convection heat transfer characteristics of air flow in a two parallel plate channel with offset plates and heated by a radiation heat flux. The SIMPLE method was used for the numerical prediction of the flow and thermal fields. The flow field temperature boundary conditions were obtained by applying the energy balance equation to boundary elements. The ray tracing technique was used to obtain the net absorbed radiation fractions in the boundary elements. The numerical results were validated with measured temperature values and experimentally calculated values of local Nusselt number (Nux), and a reasonable agreement was shown. Then the numerical simulation was used to study effects of design parameters on the convective heat transfer coefficient. It was found that in Re numbers from 650 to 2,550, the optimum spacing of offset plates relative to the nearest channel wall was around one third of the channel height. Also, the optimum offset plates’ numbers can be calculated based on one offset plate length being equal to one and a half times the channel hydraulic diameter. A correlation of average Nusselt number between the flowing air and the offset plates was obtained as follows; —Nu = 1.81 Re 0.352Pr1/3(Dh/l)1/2.
Information security in business environments
Authors: Sanderson Ethan , Forcht Karen A.
Published: July 2002

Presents a young person’s view of the threats and security measures to deal with sensitive information in today’s constantly changing technological environment. Promotes the implementation of proactive security and warns of the problems caused by converging business markets and technologies. Discusses security policy, privacy, security logs, encryption, virus attacks, Internet concerns, firewalls and auditing. Outlines the work of the Computer Emergency Response Team and the Computer Incident Advisory Capability in the USA.
Community management support through community‐based information networks
Authors: Kodama Mitsuru
Published: July 2002

Amid recent changes in the business environment and progress in IT (information technology), several companies are engaging in strategic business development by creating a variety of communities, within and outside their corporate structures. Against the backdrop of these activities, this paper explains the importance, given likely future developments, of community management for continuous activation of corporate organizations, and for new business creation. Furthermore, given the ongoing development of IT and multimedia technology, this paper proposes new applications for finance‐related businesses that use community management‐supporting community‐based information networks, and points out that community‐based information networks will become an important multimedia communication platform for business innovation.
The development of computerised library services in Pakistan
Authors: Mahmood Khalid
Published: July 2002

Computer technology in libraries has revolutionised the concept of rapid and accurate information services. In Pakistan, though, computer technology is new and is being successfully introduced in all types of libraries and information centres. This article reviews the literature on the use of computers in Pakistan’s libraries. The literature includes monographs, journal articles, reports, etc. published inside and outside Pakistan, discussing information technology, specific library applications, the activities of individual libraries and automation education. The need for library automation and the problems faced by Pakistani professionals in this respect are also discussed.
Exchange Rates and Prices: Sources of Sterling Real Exchange Rate Fluctuations 1973–94
Authors: Astley Mark S. , Garratt Anthony
Published: July 2002

We attempt to identify the sources of UK exchange rate and relative consumer price fluctuations by applying the Clarida and Gali (1994) extension of the Blanchard and Quah (1989) structural VAR method to UK data. We (r)nd that IS shocks underlay the majority of the variance of sterling real and nominal exchange rates. Aggregate supply (AS) shocks were the second most important source of such variations, while LM shocks played an extremely limited role. In contrast, the variance of UK relative consumer prices primarily reflected LM shocks.
The effects of birth weight on basal cardiovascular function in pigs at 3 months of age
Authors: Poore K. R. , Forhead A. J. , Gardner D. S. , Giussani D. A. , Fowden A. L.
Published: July 2002

In man, epidemiological studies have shown that low birth weight (BW) is associated with an increased risk of cardiovascular disease in later life. In this study, the long‐term consequences of variations in natural BW on basal cardiovascular function were investigated in pigs at 3 months of postnatal age. Low (< 1.41 kg; n= 20) and high (> 1.52 kg; n= 20) BW Large White piglets were selected from a total of 12 litters for study at 3 months of age. Basal mean arterial pressure (MAP) and heart rate (HR) were recorded for ∼30 min using standard recording equipment and basal arterial blood samples were taken for hormone analyses. Concentrations of angiotensin‐converting enzyme (ACE) were also measured in kidney, lung and plasma. Basal MAP, but not HR, in 3‐month‐old pigs was significantly inversely related to BW and positively related to the ratio of head length to BW. Postnatal growth rate of low BW pigs was slower than that of high BW pigs such that low BW piglets remained significantly smaller at 3 months of age. There were no differences in basal plasma adrenaline or cortisol concentrations between low and high BW pigs. However, basal plasma noradrenaline concentrations were significantly elevated in low BW compared to high BW pigs. Renal and pulmonary ACE levels were significantly reduced in low BW compared to high BW pigs. These data show that basal MAP in 3‐month‐old pigs is negatively associated with BW and positively correlated to disproportionate size at birth. This effect was associated with an increase in basal plasma noradrenaline concentrations.
A novel mechanism of response selectivity of neurons in cat visual cortex
Authors: Volgushev Maxim , Pernberg Joachim , Eysel Ulf T.
Published: July 2002

The spiking of cortical neurons critically depends on properties of the afferent stimuli. In the visual cortex, neurons respond selectively to the orientation and direction of movement of an object. The orientation and direction selectivity is improved upon transformation of the membrane potential changes into trains of action potentials. To address the question of whether the transformation of the membrane potential changes into spiking of a cell depends on the stimulus orientation and the direction of movement, we made intracellular recordings from the cat visual cortex in vivo during presentation of moving gratings of different orientations. We found that the relationship between the membrane polarization and the firing rate (input‐output transfer function) depended on the stimulus orientation. The input‐output transfer function was steepest during responses to the optimal stimulus; membrane depolarization of a given amplitude led to generation of more action potentials when evoked by an optimal stimulus than during non‐optimal stimulation. The threshold for the action potential generation did not depend on stimulus orientation, and thus could not account for the observed difference in the transfer function. Oscillations of the membrane potential in the γ‐frequency range (25–70 Hz) were most pronounced during optimal stimulation and their strength changed in parallel with the changes in the transfer function, suggesting a possible relationship between the two parameters. We suggest that the improved input‐output relationship of neurons during optimal stimulation represents a novel mechanism that may contribute to the final sharp orientation selectivity of spike responses in the cortical cells.
Excitability changes in human corticospinal projections to forearm muscles during voluntary movement of ipsilateral foot
Authors: Baldissera Fausto , Borroni Paola , Cavallari Paolo , Cerri Gabriella
Published: July 2002

Excitability of the H‐reflex in the relaxed flexor carpi radialis (FCR) muscle was tested during voluntary oscillations of the ipsilateral foot at five evenly spaced delays during a 600 ms cycle. In some experiments the H‐reflex was conditioned by transcranial magnetic stimulation (TMS). With the hand prone, the amplitude of the FCR H‐reflex was modulated sinusoidally with the same period as the foot oscillation, the modulation peak occurring in coincidence with contraction of the foot plantar‐flexor soleus and the trough during contraction of the extensor tibialis anterior. When the H‐reflex was facilitated by TMS at short latency (conditioning‐test interval: −2 to −3.5 ms), the modulation was larger than that occurring with an unconditioned reflex of comparable size. This suggests that both the peripheral and the corticospinal components of the facilitated response were modulated in parallel. When the H‐reflex was tested 40–60 ms after conditioning, i.e. during the cortical ‘silent period’ induced by TMS, no direct effect was produced on the reflex size but the foot‐associated modulation was deeply depressed. These results suggest that the reflex modulation may depend on activity fluctuations in the cortical motor area innervating the forearm motoneurones. It is proposed that when the foot is rhythmically oscillated, along with the full activation of the foot cortical area a simultaneous lesser co‐activation of the forearm area produces a subliminal cyclic modulation of cervical motoneurones excitability. Should the two limbs be moved together, the time course of this modulation would favour isodirectional movements of the prone hand and foot, indeed the preferential coupling observed when hand and foot are voluntarily oscillated.
Mechanism of Kir6.2 channel inhibition by sulfhydryl modification: pore block or allosteric gating?
Authors: Cui Yijun , Fan Zheng
Published: July 2002

Chemical modification can inhibit ion channels either by reacting with pore‐lining residues and directly occluding the channel or by closing the channel allosterically. A general method to distinguish between these two mechanisms does not exist. Previously, sulfhydryl (SH) modification has been shown to inhibit ATP‐sensitive K+ (KATP) channels. The crucial modification has been localized to C42 near the N‐terminus of Kir6.2, a pore‐forming subunit of KATP channels, but little is known about how SH modification of C42 causes channel inhibition. To investigate this mechanism, we used the membrane‐impermeable methanethiosulfonates, MTSET and MTS‐TEAH, to modify Kir6.2 channels. While intracellular application of MTSET irreversibly inhibited channels, MTS‐TEAH failed to do so. Instead, MTS‐TEAH treatment prolonged channel openings and prevented the effect of subsequent MTSET treatment. Similar observations were made in mutants in which cysteines other than C42 had been mutated. Neither MTSET nor MTS‐TEAH, however, affected mutant channels in which valines were substituted for C42 residues in all subunits. The reagents were effective when two of four C42 residues in the tetramer were replaced by valines. These results can be interpreted as indicating that both reagents modify C42. We then employed spermine, a known inner pore blocker, as a probe to examine whether MTS‐TEAH modification alters pore accessibility. We found that spermine block was not changed by MTS‐TEAH modification. Based on these data, we postulate that C42 faces either the cytoplasm or a vestibule section wide enough to allow spermine to pass freely after modification by MTS‐TEAH. Our study suggests that channel inhibition caused by SH modification of Kir6.2 is an allosteric effect, and is not caused by direct pore blockage.
Phosphorylation and functional regulation of CIC‐2 chloride channels expressed in Xenopus oocytes by M cyclin‐dependent protein kinase
Authors: Furukawa Tetsushi , Ogura Takehiko , Zheng Ya‐Juan , Tsuchiya Hiroyuki , Nakaya Haruaki , Katayama Yoshifumi , Inagaki Nobuya
Published: July 2002

Many dramatic alterations in various cellular processes during the cell cycle are known to involve ion channels. In ascidian embryos and Caenorhabditis elegans oocytes, for example, the activity of inwardly rectifying Cl− channels is enhanced during the M phase of the cell cycle, but the mechanism underlying this change remains to be established. We show here that the volume‐sensitive Cl− channel, ClC‐2 is regulated by the M‐phase‐specific cyclin‐dependent kinase, p34cdc2/cyclin B. ClC‐2 channels were phosphorylated by p34cdc2/cyclin B in both in vitro and cell‐free phosphorylation assays. ClC‐2 phosphorylation was inhibited by olomoucine and abolished by a 632Ser‐to‐Ala (S632A) mutation in the C‐terminus, indicating that 632Ser is a target of phosphorylation by p34cdc2/cyclin B. Injection of activated p34cdc2/cyclin B attenuated the ClC‐2 currents but not the S632A mutant channel currents expressed in Xenopus oocytes. ClC‐2 currents attenuated by p34cdc2/cyclin B were increased by application of the cyclin‐dependent kinase inhibitor, olomoucine (100 μm), an effect that was inhibited by calyculin A (5 nm) but not by okadaic acid (5 nm). A yeast two‐hybrid system revealed a direct interaction between the ClC‐2 C‐terminus and protein phosphatase 1. These data suggest that the ClC‐2 channel is also counter‐regulated by protein phosphatase 1. In addition, p34cdc2/cyclin B decreased the magnitude of ClC‐2 channel activation caused by cell swelling. As the activities of both p34cdc2/cyclin B and protein phosphatase 1 vary during the cell cycle, as does cell volume, the ClC‐2 channel could be regulated physiologically by these factors.
A Reduction Method for the Boundary Control of the Heat Conduction Equation
Authors: Park H. M. , Kim O. Y.
Published: July 2002

The Karhunen–Loe`ve Galerkin procedure (Park, H. M., and Cho, D. H., 1996, “Low Dimensional Modeling of Flow Reactors,” Int. J. Heat Mass Transf., 39, pp. 3311–3323) is a type of reduction method that can be used to solve linear or nonlinear partial differential equations by reducing them to minimal sets of algebraic or ordinary differential equations. In this work, the method is used in conjunction with a conjugate gradient technique to solve the boundary optimal control problems of the heat conduction equations. It is demonstrated that the Karhunen–Loe`ve Galerkin procedure is well suited for the problems of control or optimization, where one has to solve the governing equations repeatedly but one can also estimate the approximate solution space based on the range of control variables. Choices of empirical eigenfunctions to be employed in the Karhunen–Loe`ve Galerkin procedure and issues concerning the implementations of the method are discussed. Compared to the traditional methods, the Karhunen–Loe`ve Galerkin procedure is found to solve the optimal control problems very efficiently without losing accuracy. [S0022-0434(00)00603-1]
Experimental Evaluation of the Laser Assisted Machining of Silicon Nitride Ceramics
Authors: Rozzi Jay C. , Pfefferkorn Frank E. , Shin Yung C. , Incropera Frank P.
Published: July 2002

To assess the feasibility of the laser assisted machining (LAM) process for the machining of difficult-to-machine materials such as structural ceramics, experiments were performed on silicon nitride workpieces for a wide range of operating conditions. Data for cutting forces and surface temperatures indicate that the lower bound of the material removal temperature for avoidance of cutting tool and/or workpiece fracture corresponds to the YSiAlON glass transition temperature (920–970°C). As temperatures near the cutting tool increase to values above the glass transition temperature, the glassy phase softens, facilitating visco-plastic flow and, correspondingly, the production of semi-continuous or continuous chips. The silicon nitride workpiece machined had a surface roughness of Ra=0.39 μm at the nominal LAM operating condition. Examination of the machined surfaces and chips reveals no detectable sub-surface cracking or significant changes in microstructure, respectively. Relative to grinding, the most significant advantage of LAM is its ability to achieve much larger material removal rates with high workpiece surface quality and reasonable levels of tool wear. [S1087-1357(00)00704-8]
Validity of Photoelastic Strain Measurement on Cadaveric Proximal Femora
Authors: Glisson Richard R. , Musgrave Douglas S. , Graham Robert D. , Vail Thomas P.
Published: July 2002

Rosette strain gages indicate shear and principal strains at specific points, whereas photoelastic coatings provide shear strain information over a broad area. Information regarding bone loading and load transfer from a prosthetic implant to adjacent bone can be obtained using either strain-measuring technique on loaded femora. This study compared proximal femoral strains derived from photoelastic coatings to those obtained from rosette strain gages applied directly to the bone in order to determine the relationships between photoelastic shear strains and rosette shear and principal strains. Photoelastic shear strains underestimated rosette shear strains and exceeded the larger of the rosette principal strains. Principal strains derived from photoelastic coatings augmented with strain separator gages underestimated their rosette counterparts in most instances. Correlation was strong and nearly linear for all measures, indicating that photoelastic coatings can accurately express proportional strain changes despite imperfect agreement in absolute strain magnitudes. The best agreement between absolute strain magnitudes occurred in the proximal medial, or calcar, region. Understanding the relationships between the various measures obtained using the two strain measurement methods will allow more accurate estimates of actual strains to be made from photoelastic coatings. [S0148-0731(00)01704-0]
Numerical and Experimental Investigation of Unsteady Flow Interaction in a Low-Pressure Multistage Turbine
Authors: Ho¨hn Wolfgang , Heinig Klaus
Published: July 2002

This paper presents results of unsteady viscous flow calculations and corresponding cold flow experiments of a three-stage low-pressure turbine. The investigation emphasizes the study of unsteady flow interaction. A time-accurate Reynolds-averaged Navier–Stokes solver is applied for the computations. Turbulence is modeled using the Spalart–Allmaras one-equation turbulence model and the influence of modern transition models on the unsteady flow predictions is investigated. The integration of the governing equations in time is performed with a four-stage Runge–Kutta scheme, which is accelerated by a two-grid method in the viscous boundary layer around the blades. At the inlet and outlet, nonreflecting boundary conditions are used. The quasi-three-dimensional calculations are conducted on a stream surface around midspan, allowing a varying stream tube thickness. In order to study the unsteady flow interaction, a three-stage low-pressure turbine rig of a modern commercial jet engine is built up. In addition to the design point, the Reynolds number, the wheel speed, and the pressure ratio are also varied in the tests. The numerical method is able to capture important unsteady effects found in the experiments, i.e., unsteady transition as well as the blade row interaction. In particular, the flow field with respect to time-averaged and unsteady quantities such as surface pressure, entropy, and skin friction is compared with the experiments conducted in the cold air flow test rig. [S0889-504X(00)02004-3]
Separation Bubbles Under Steady and Periodic-Unsteady Main Flow Conditions
Authors: Lou Weiliang , Hourmouziadis Jean
Published: July 2002

Based on an experimental investigation carried out in a low-speed test facility at the Berlin University of Technology, this paper describes the formation of separation bubbles under steady and periodic-unsteady main flow conditions. The aim of the investigation was to understand the mechanism of separation, transition, and reattachment, and the effect of main flow unsteadiness on it. Separation bubbles for various main flow conditions were generated over a large flat plate, which experienced a similar pressure distribution to that on the suction surface of blades in turbomachines. The pressure distribution was generated by a contoured wall opposite the plate. Aimed at separating the effect of the velocity and the turbulence wake, this paper considers only the influence of the velocity wake. To this effect, a rotating flap was mounted downstream of the test section to produce periodic oscillations of the main flow. The overall flow field under steady main flow conditions was obtained by hot-wire measurements. Pressure taps were used to measure the pressure distribution over the plate. The Reynolds number effects were determined and compared to the measurement results in the literature. Results for periodic-unsteady separation bubbles are shown using different Strouhal numbers, oscillation amplitudes, and Reynolds numbers. Ensemble-averaged mean velocity profiles and the ensemble-averaged rms velocity profiles are used to demonstrate the development of the periodic boundary layer. Time–space diagrams are plotted to show the development of the periodic-unsteady boundary layers. The characteristic instability frequencies in the free shear layer are identified. The impact of the major parameters, Strouhal number and amplitude, on the bubble formation are discussed. [S0889-504X(00)01204-6]
On the Characterization of Dynamic Properties of Random Processes by Spectral Parameters
Authors: Petrucci G. , Di Paola M. , Zuccarello B.
Published: July 2002

This paper deals with the general problem of directly relating the distribution of ranges of wide band random processes to the power spectral density (PSD) by means of closed-form expressions. Various attempts to relate the statistical distribution of ranges to the PSD by means of the irregularity factor or similar parameters have been done by several authors but, unfortunately, they have not been fully successful. In the present study, introducing the so-called analytic processes, the reasons for which these parameters are insufficient to an unambiguous determination of the range distribution and the fact that parameters regarding the time-derivative processes are needed have been explained. Furthermore, numerical simulations have shown that the range distributions depend on the irregularity factor and bandwidth parameter of both the process and its derivative. These observations are the basis for the determination of accurate relationships between range distributions and PSDs. [S0021-8936(00)02903-2]
Combustion-Thermoelectric Tube
Authors: Park C.-W. , Kaviany M.
Published: July 2002

In direct combustion-thermoelectric energy conversion, direct fuel injection and reciprocation of the air flowing in a solid matrix are combined with the solid-gas interfacial heat transfer and the solid conduction to allow for obtaining superadiabatic temperatures at the hot junctions. While the solid conductivity is necessary, the relatively large thermal conductivity of the available high-temperature thermoelectric materials (e.g., Si–Ge alloys) results in a large conduction loss from the hot junctions and deteriorates the performance. Here, a combustion-thermoelectric tube is introduced and analyzed. Radially averaged temperatures are used for the fluid and solid phases. A combination of external cooling of the cold junctions, and direct injection of the fuel, has been used to increase the energy conversion efficiency for low thermal conductivity, high-melting temperature thermoelectric materials. The parametric study (geometry, flow, stoichiometry, materials) shows that with the current high figure of merit, high temperature Si0.7Ge0.3 properties, a conversion efficiency of about 11 percent is achievable. With lower thermal conductivities for these high-temperature materials, efficiencies about 25 percent appear possible. This places this energy conversion in line with the other high efficiency, direct, electric power generation methods. [S0022-1481(00)01304-9]
Deformation, Stress State, and Thermodynamic Force for a Transforming Spherical Inclusion in an Elastic-Plastic Material
Authors: Fischer F. D. , Oberaigner E. R.
Published: July 2002

The progress of a transformed phase into an elastic-plastic parent phase is simulated by a growing sphere. The transformation is accompanied by a dilatational volume change. The strain and stress state in the full space is presented. In addition, the local and global energy terms are calculated. Finally the thermodynamic forces on the interface are derived. Also strain hardening is considered. [S0021-8936(00)00304-4]
Theoretical Modeling of Creep Behavior of Bellows and Some Applications
Authors: Tsukimori Kazuyuki
Published: July 2002

The use of bellows expansion joints is an effective method to rationalize various piping systems in industry. In the structural design, the requirements for preventing failures such as ratcheting, fatigue, and buckling should be satisfied. The mechanisms of some failure modes of bellows are different from those of vessels and piping components, which makes it difficult to estimate the behaviors. In the case of high-temperature operation, creep behavior of bellows should be considered. In this paper, a simplified theoretical modeling of creep behavior of bellows is presented. The formulation is developed by using Norton’s law for creep property of bellows material and assuming meridional bending stress is dominant. According to this modeling, bellows convolution dimensions are considered directly. The excessive creep deformation problem of bellows under internal pressure and the elastic follow-up behavior problem of a piping system with bellows expansion joints are examined as the applications of this modeling. The results are compared with detailed analysis results by FEM, and the applicability and the validity of this modeling is discussed.
Influence of Alpha Casing on Superplastic Deformation of Ti-6Al-4V
Authors: Patankar S. N. , Tan M. J.
Published: July 2002

Impact of alpha casing on the superplastic deformation of Ti-Al-4V was studied by applying an oxygen barrier coating onto the surface prior to superplastic forming and mechanical testing at elevated temperature.
A Triangle Based Finite Volume Method for the Integration of Lubrication’s Incompressible Bulk Flow Equations
Authors: Arghir Mihai , Fre^ne Jean
Published: July 2002

It is well known that for a reduced Reynolds number Re*=ρVH/μs˙H/L greater than unity, inertia forces have a dominant effect in the transport equations, thus rendering the classical lubrication equation inapplicable. The so called “bulk flow” system of equations is then the appropriate mathematical model for describing the flow in bearing and seals operating at Re*⩾1. The difficulty in integrating this system of equations is that one has to deal with coupled pressure and velocity fields. Analytic methods have a very narrow application range so a numerical method has been proposed by Launder and Leschziner in 1978. It represents a natural extrapolation of the successful SIMPLE algorithm applied to the bulk flow system of equations. The algorithm used rectangular, staggered control volumes and represented the state of the art at that moment. In the present work we introduced a method using triangular control volumes. The basic advantage of triangles versus rectangles is that non rectangular domains can be dealt without any a priori limitation. The present paper is focused on the description of the discretized equations and of the solution algorithm. Validations for bearings and seals operating in incompressible, laminar and turbulent flow regime are finally proving the accuracy of the method.
Flip-Chip BGA Design to Avert Die Cracking
Authors: Han J.-B.
Published: July 2002

Fracture mechanics is applied to flip-chip BGA design to avert die cracking from its backside. Fracture mechanics is integrated with the finite element analysis (FEA) and design of virtual experiments (virtual DOE) to analyze the effects of location and length of a die crack, and the effects of some key material properties and package dimensions on die cracking of flip-chip BGA. The stress intensity factor (SIF) and the strain energy release rate (ERR) are taken as the design indices. The FEA is used to calculate the fracture parameters, and the virtual DOE is employed to determine contributions of each design parameter to die cracking and their acceptable design windows. The investigation consists of two parts. The first is relations of length and location of a die crack with the fracture parameters. The relations are established through sweeping along crack length for a crack located at the center of the die backside, and along the die backside surface. The critical crack length is determined for a specific design. The second is the virtual DOE based on fracture mechanics. Several key material properties and package dimensions are used as the design inputs. The main effects and interactions of these design parameters to die cracking are calculated. Based on it, some generic design guidelines are made. It is concluded that substrate and die thicknesses are the two most significant factors to die cracking of flip-chip BGA. Increasing substrate thickness and reducing die thickness are the most effective measures to design a package with high resistance to die cracking.
Experimental Study of Heat Convection From Stationary and Oscillating Circular Cylinder in Cross Flow
Authors: Park H. G. , Gharib Morteza
Published: July 2002

An experimental study is made on the processes of heat transfer from the surface of a forced oscillating cylinder in a crossflow. A range of oscillation amplitude A/D=0.1,0.2, forced oscillation frequency 0<Stc<1, and Reynolds number (Re=550, 1100, 3500) is covered in water Pr=6. Besides the increase at the natural vortex shedding frequency, large increases in the heat transfer are found at certain superharmonics. By using Digital Particle Image Velocimetry/Thermometry (DPIV/T), the increase in the heat transfer rate is found to correlate inversely with the distance at which vortices roll-up behind the cylinder, i.e., the distance decreases when the heat transfer increases. The cause of the increase is found to be the removal of the stagnant and low heat convecting fluid at the base of the cylinder during the roll-up of the vortices.
Simplified Analytical Models for Forced Convection Heat Transfer From Cuboids of Arbitrary Shape
Authors: Culham J. R. , Yovanovich M. M. , Teertstra P. , Wang C.-S. , Refai-Ahmed G. , Tain Ra-Min
Published: July 2002

Three analytical models are presented for determining laminar, forced convection heat transfer from isothermal cuboids. The models can be used over a range of Reynolds number, including at the diffusive limit where the Reynolds number goes to zero, and for a range of cuboid aspect ratios from a cube to a flat plate. The models provide a simple, convenient method for calculating an average Nusselt number based on cuboid dimensions, thermophysical properties and the approach velocity. Both the cuboid and the equivalent flat plate models are strongly dependent upon the flow path length which is bounded between two easily calculated limits. In comparisons with numerical simulations, the models are shown to be within ±6 percent over the range of 0⩽ReA⩽5000 and aspect ratios between 0 and 1.
An Experimental Study of the Effect of Wake Passing on Turbine Blade Film Cooling
Authors: Heidmann James D. , Lucci Barbara L. , Reshotko Eli
Published: July 2002

The effect of wake passing on the showerhead film cooling performance of a turbine blade has been investigated experimentally. The experiments were performed in an annular turbine cascade with an upstream rotating row of cylindrical rods. Nickel thin-film gauges were used to determine local film effectiveness and Nusselt number values for various injectants, blowing ratios, and Strouhal numbers. Results indicated a reduction in film effectiveness with increasing Strouhal number, as well as the expected increase in film effectiveness with blowing ratio. An equation was developed to correlate the span-average film effectiveness data. The primary effect of wake unsteadiness was found to be correlated by a streamwise-constant decrement of 0.094St. Steady computations were found to be in excellent agreement with experimental Nusselt numbers, but to overpredict experimental film effectiveness values. This is likely due to the inability to match actual hole exit velocity profiles and the absence of a credible turbulence model for film cooling.
Limit Pressures of Cylindrical and Spherical Shells
Authors: Kalnins Arturs , Updike Dean P.
Published: July 2002

Tresca limit pressures for long cylindrical shells and complete spherical shells subjected to arbitrary pressure, and several approximations to the exact limit pressures for limited pressure ranges, are derived. The results are compared with those in Section III-Subsection NB and in Section VIII-Division 2 of the ASME B&PV Code. It is found that in Section VIII-Division 2 the formulas agree with the derived limit pressures and their approximations, but that in Section III-Subsection NB the formula for spherical shells is different from the derived approximation to the limit pressure. The length effect on the limit pressure is investigated for cylindrical shells with simply supported ends. A geometric parameter that expresses the length effect is determined. A formula and its limit of validity are derived for an assessment of the length effect on the limit pressures.
Automated Layout Generation and Wiring Area Estimation for 3D Electronic Modules
Authors: Scha¨fer Mike , Lengauer Thomas
Published: July 2002

This paper presents an integrated approach to the layout generation of 3D rectagonal objects and wiring area estimation. Problems of this type are encountered in various component layout tasks such as the space-efficient placement of electronic components in automobiles. The goal is to achieve high packing densities and fitting of objects in predefined design spaces while satisfying spatial constraints. The layout problem is formulated as mixed integer linear program and can be solved either by a branch&bound procedure or heuristically. The wiring area estimation is integrated in the problem formulation on the basis of a number of explicit wiring variants for each cable.
Virtual Web Plant: An Internet-Based Plant Engineering Information System
Authors: Ebbesmeyer Peter , Gausemeier Ju¨rgen , Krumm Holger , Molt Thorsten , Gruß Thomas
Published: July 2002

During the development of the European Pressurized Water Reactor Project (EPR)—an innovative design concept for a new type of pressurized water reactor—large amounts of up-to-date engineering data (i.e., CAD data, planning documentation) have to be made available to all international project partners for presentation and development. This paper describes the web-based tool Virtual Web Plant (VWP), a tool to integrate three-dimensional models from various CAD plant design tools and to display them interactively. The user is hereby able to navigate easily through both the plant structure and the project documentation. The work presented in this paper is part of a Virtual Reality Research Project of the Heinz Nixdorf Institute and the Siemens AG KWU.
Using Variability Related to Families of Spectral Estimators for Mixed Random Processes
Authors: Wen Li , Wang Changxue , Sherman Peter
Published: July 2002

Traditionally, characterization of spectral information for wide sense stationary processes has been addressed by identifying a single best spectral estimator from a given family. If one were to observe significant variability in neighboring spectral estimators then the level of confidence in the chosen estimator would naturally be lessened. Such variability naturally occurs in the case of a mixed random process, since the influence of the point spectrum in a spectral density characterization arises in the form of approximations of Dirac delta functions. In this work we investigate the nature of the variability of the point spectrum related to three families of spectral estimators: Fourier transform of the truncated unbiased correlation estimator, the truncated periodogram, and the autoregressive estimator. We show that tones are a significant source of bias and variability. This is done in the context of Dirichlet and Fejer kernels, and with respect to order rates. We offer some expressions for estimating statistical and arithmetic variability. Finally, we include an example concerning helicopter vibration. These results are especially pertinent to mechanical systems settings wherein harmonic content is prevalent.
MOB Platform Nonlinear Dynamics in a Realistic (Random) Seaway
Authors: Vishnubhotla S. , Falzarano J. , Vakakis A.
Published: July 2002

In this work, our previously developed approach is extended to include parametric excitation. This approach makes use of a closed-form analytic solution, which is exact up to the first order of randomness and takes into account the unperturbed (no forcing or damping) global dynamics. The result of this is that very large amplitude nonlinear vessel motion in a random seaway can be analyzed with similar techniques used to analyze nonlinear vessel motions in a regular (periodic) seaway. The practical result is that dynamic capsizing studies can be undertaken considering the true randomness of the design seaway. The capsize risk associated with operation in a given sea spectrum can be evaluated during the design stage or when an operating area change is being considered. Moreover, this technique can also be used to guide physical model tests or computer simulation studies to focus on critical vessel and environmental conditions which may result in dangerously large motion amplitudes.
Screening Analysis for EPACT-Covered Commercial HVAC and Water-Heating Equipment
Authors: Somasundaram Sriram , Winiarski David W. , Belzer David B.
Published: July 2002

PNNL, under direction from DOE, conducted a screening analysis to determine the energy savings potential from the efficiency levels for commercial HVAC and water-heating equipment listed in Standard 90.1-1999, as well as the potential from several higher efficiency levels. We estimated the annual energy consumption for each type of equipment, at various efficiency levels, through engineering simulations for seven building types in 11 U.S. locations. We also conducted an economic analysis to identify the efficiency levels that would provide the highest value of economic benefits. From 2004 through 2030, the estimated national energy savings for the equipment meeting the Standard 90.1-1999 efficiency levels is about 3.8 exajoules (EJ) (3.6 quads).1 The total estimated carbon emissions reduction is 52 MMtons.
The Distortion of a Jet by Coil Inserts
Authors: Hoang Huy T. , Rahai Hamid R.
Published: July 2002

Results of experimental investigations of the effects of distortion caused by coil inserts on a turbulent jet are presented. The coils have different wire diameters with constant pitch spacing. The ratios of the coil wire diameter to the tube inside diameter, d/D, are 0.06, 0.08, 0.11, 0.13, and 0.16 and the ratio of the pitch spacing to the tube inside diameter, p/D, is 1.2. Results show that the coil inserts enhance the mixing process. At the jet-outlet, mixing enhancement is increased when d/D<0.1. However, further downstream, the highest mixing is achieved for the coil with the largest d/D ratio. Results suggest that the streamwise vortices generated by the coil inserts are the mechanism behind the high entrainments and the mixing process.
Theoretical and Experimental Investigations of an Opto-Pneumatic Detector
Authors: Belforte G. , Raparelli T. , Viktorov V. , Eula G. , Ivanov A.
Published: July 2002

The following is a theoretical and experimental study of an opto-pneumatic detector (OPD) used in an opto-pneumatic interface. This interface is capable of changing an optical signal into a pneumatic one, that can be amplified and then applied to pneumatic power stages. The opto-pneumatic interface offers the greatest promise in the automation of installations located under fire and explosive-hazardous conditions and under conditions where there are electromagnetic or radiation field actions, whereby electrical communication channel application is undesirable or impossible, and where pneumatic channels do not provide the required speed of response. The OPD is made up of a cell where an infrared light signal cuts into a black-body, increases its temperature, and generates a pressure signal in the chamber. The work has been carried out using different absorption body thickness, gas chamber volumes, different optical signal frequencies, and different fluid loads of the OPD. Following this, a mathematical model for numerical computation has been elaborated. The theoretical results were compared with the experimental results. [S0022-0434(00)00101-5]
Evaluation of Inflow Performance of Multiple Horizontal Wells in Closed Systems
Authors: Umnuayponwiwat Suwan , Ozkan Erdal
Published: July 2002

This work presents a model to investigate the inflow performance relationships (IPR) of horizontal and vertical wells in a multi-well pattern. The model can be used to compute the overall and individual well performances. It is shown that stabilized IPRs may not be sufficient for the evaluation of horizontal well performances due to prolonged transient flow periods. The results presented in this paper clearly indicate that inflow performance of wells in a multi-well pattern is a dynamic concept; and, especially in the prediction of future performances, dynamic rather than static IPR models should be used. [S0195-0738(00)00801-3]
IN MEMORIAM
Authors: Komanduri Ranga
Published: July 2002

[S1087-1357(00)02101-8]
Discussion: “Operation of Foil Bearings Beyond the Bending Critical Mode” [ASME J. Tribol., 122, No. 1, pp. 192–198 (2000)]1
Authors: Green I.
Published: July 2002

[S0742-4787(00)02702-8]
Evolution of Section XI of the ASME Boiler and Pressure Vessel Code
Authors: Hedden Owen F.
Published: July 2002

This article will describe the development of Section XI from a pamphlet-sized document to the lengthy and complex set of requirements, interpretations, and Code Cases that it has become by the year 2000. Section XI began as a set of rules for inservice inspection of the primary pressure boundary system of nuclear power plants. It has evolved to include other aspects of maintaining the structural integrity of safety class pressure boundaries. These include procedures for component repair/replacement activities, analysis of revised and new plant operating conditions, and specialized provisions for nondestructive examination of components and piping. It has also increased in scope to cover other Section III construction: Class 2, Class 3 and containment structures. First, to provide a context for the discussions to follow, the differences in administration and enforcement between Section XI and the other Code Sections will be explained, including its dependence on the US Nuclear Regulatory Commission. The importance of interpretations and Code Cases then will be discussed. The development of general requirements and requirements for each class of structure will be traced. The movement of Section XI toward a new philosophy, risk-informed inspection, will also be discussed. Finally, an annotated bibliography of papers describing the philosophy and technical basis behind Section XI will be provided. [S0094-9930(00)01703-0]
Fluorescein by XPS
Authors: Mansour Azzam N. , Beard Bruce C. , Cronce Donald T. , Brown Russell P.
Published: July 2002

X-ray photoemission spectra of the core and valence levels for fluorescein are presented. The data were collected on a Perkin-Elmer/Physical Electronics model #5400 photoelectron spectrometer using unmonochromatized Mg x rays. The material, in powder form, was analyzed in the as received condition. Fluorescein is an important prototype organic dye with molecular formula C20H12O5. It consists of four benzene rings modified by the presence of a carboxylic, a carbonyl, a hydroxyl, and an ether type bonding. Due to the specific nature of these carbon chemistries, fluorescein is being used as a reference material to aid in understanding the chemistry of various functional groups present on oxidized activated carbons. Quantitative XPS atomic percent for carbon and oxygen are in excellent agreement with those based on its molecular formula. The various carbon and oxygen chemistries observed in this investigation are also consistent with those based on fluorescein structure.
Nickel by XPS
Authors: Miller A. C. , Simmons G. W.
Published: July 2002

High energy resolution XPS spectra of sputter cleaned Ni (2 keV, Ar+1) are presented. The experimental width (16%–84% measurement) of the Fermi level was 0.32 ± 0.02 eV. The energy scale calibration is based on the Fermi level.