bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual Stress Measurement in Spot Welds and the Effect of Fatigue Loading on Redistribution of Stresses Using High Sensitivity Moire´ Interferometry
Authors: Khanna Sanjeev K. , He Canlong , Agrawal Hari N.
Published: July 2002

Residual stress distribution has been determined in spot welds, which are generally used to join mild steel sheets. Various spot weld configurations were investigated using the full-field, experimental, optical technique of high sensitivity moire´ interferometry. These stresses were found to be in the range 250–300 MPa (tensile) in the center and decreased to 40–100 MPa (tensile) at the edge of the weld nugget. Low cycle fatigue loading of the spot weld caused the residual stress to drop in the weld center by about 30 percent and increase at the edges by as much as 100 percent.
Signal Analysis Using Karhunen-Loe`ve Transformation: Application to Hydrodynamic Forces
Authors: Tumer Irem Y. , Longoria Raul G. , Wood Kristin L.
Published: July 2002

This paper describes a signal analysis method using the Karhunen-Loe`ve (KL) transform, and applies the method to the analysis of hydrodynamic force data collected from controlled laboratory experiments. To demonstrate feasibility, the study focuses on inline forces induced on fixed cylinders exposed to oscillatory flows, with increasing Keulegan-Carpenter numbers. This preliminary example illustrates how this force makes a transition from the inertia-dominated region at low Keulegan-Carpenter numbers up into higher Keulegan-Carpenter numbers where the nonlinear effects of the flow-structure interaction can be observed through the increased influence of clearly defined modes. [S0892-7219(00)00603-8]
Solar Selective Properties of Electrolytically Formed Thin Layers on Aluminum
Authors: Mo¨ller T. , Schwarz Th. , Ho¨nicke D.
Published: July 2002

A novel electrochemical process for the formation of solar selective absorber layers on aluminum is presented. The growth of an alumina layer and the incorporation of metal ions into the layer is done by a one-step procedure using only one electrolytic bath and application of a voltage pulse technique. The influence of selected electrical parameters on the solar selective properties is described and the enhanced stability of an absorber layer, attained by a sol-gel-posttreatment, is discussed. [S0199-6231(00)00602-X]
Discussion: “The Influence of Technical Surface Roughness Caused by Precision Forging on the Flow Around a Highly Loaded Compressor Cascade” [ASME J. Turbomach., 122, No. 3, pp. 416–424 (2000)]1
Authors: Cumpsty N. A.
Published: July 2002

[S0889-504X(00)02003-1]
Transient Response of an Infinite Elastic Medium Containing a Spherical Cavity Subjected to Torsion
Authors: Zakout U. , Akkas Z. , Tupholme G. E.
Published: July 2002

An exact closed-form solution is obtained for the transient response of an infinite isotropic elastic medium containing a spherical cavity subjected to torsional surface loading using the residual variable method. The main advantage of the present approach is that it eliminates the computational problems arising in the existing methods which are primarily based on Fourier or Laplace transformation techniques. Extensive numerical results for the circumferential displacements and shear stresses at various locations are presented graphically for Heaviside loadings. [S0021-8936(00)01102-8]
The Pressure-Viscosity Coefficient of a Perfluorinated Polyether Over a Wide Temperature Range
Authors: Bair Scott
Published: July 2002

An unbranched perfluoropolyether is the current ball bearing lubricant for deep space flight. We report measurements of viscosity to moderate pressures for the calculation of pressure-viscosity coefficients to temperatures as low as −40°C. A free volume model predicts that a minimum pressure-viscosity coefficient exists at higher temperature. The existence of a minimum αoT is confirmed by viscometry at temperatures to 180°C.
Forced Response of PZT Glide Heads1
Authors: Ou-Yang Jin-Hui , Tsay Alex Y. , Shen I. Y. , Ku C.-P. Roger , Kuo David
Published: July 2002

This paper studies forced response of PZT glide heads through calibrated experiments and finite element analyses. The PZT glide heads consist of an Al2O3TiC slider and a PZT transducer. In the first part of the research, the PZT transducer serves as an actuator exciting the glide heads from 100 kHz to 1.3 MHz. A laser Doppler vibrometer (LDV) and an impedance analyzer are used to measure frequency response functions (FRF) and PZT impedance. In addition, the response of the PZT glide heads is simulated through finite element analyses (FEA). The FEA predict the resonance frequencies with less than 5 percent difference. For the first two slider modes, the FEA also predict resonance amplitudes with good accuracy. In the second part of the research, the PZT transducer serves as a sensor, and the glide head is subjected to an impact force. To produce short impacts experimentally, miniature balls are dropped to the glide heads. The impact force is estimated through the impact duration and the momentum change before and after the impact. Then the impact force and the PZT output voltage are processed to produce FRF. Since the PZT sensor and its circuit form a high-pass filter, the FEA need to consider the slider, the PZT transducer, and the electric circuits simultaneously to produce meaningful results. The FEA predictions agree with the experimental measurements for the first two slider modes as well. [S0742-4787(00)01004-3]
Stochastic Fatigue Damage Accumulation Due to Nonlinear Ship Loads
Authors: Jha Alok K. , Winterstein Steven R.
Published: July 2002

Efficient methods are described here to predict the stochastic accumulation of fatigue damage due to nonlinear ship loads that are produced in random seas. The stochastic analysis method, which may be applied both to overload and fatigue limit states, is based on a relatively new concept: the nonlinear transfer function (NTF) method. The basic goal of this method is to require the use of a generally expensive, nonlinear time-domain ship load analysis for only a limited set of idealized, regular waves. This establishes the so-called nonlinear transfer function; i.e., the generally nonlinear transformation from wave amplitude and period to the load amplitude measure of interest (e.g., total load range for rainflow-counting, tensile portion for crack propagation, etc.). Stochastic process theory is used 1) to identify a minimal set of regular waves (i.e., heights and periods) to be applied, 2) to assign an appropriate set of “side-waves” to be spatially distributed along the ship, and 3) to determine how these results should be weighted in predicting statistics of the loads produced in random seas. The result is compared here with full nonlinear analysis of a specific ship, over long simulations of an irregular sea. A ship with relatively flared cross section is chosen, which shows marked nonlinearity, and hence asymmetry in its positive and negative (sag and hog) midship bending moment. The NTF method is shown to accurately predict the results of the long nonlinear simulations. This suggests the potential for considerable reduction in analysis costs: time-domain analysis over many cycles of an irregular sea is replaced by a limited number of regular wave analyses. [S0892-7219(00)00704-4]
In-Situ Wear Monitoring of Slider and Disk Using Acoustic Emission
Authors: Matsuoka Kaoru , Taniguchi Koji , Nakakita Masaru
Published: July 2002

The methodology has been developed for both the evaluation and analysis of slider/disk interface phenomena. We have been studying the direct relationships between the acoustic emission (AE) signal and wear of materials. The power in the AE signal is directly related to the power required for material removal in the wear process. This technique has been successfully applied to monitoring the wear of the tri-pad contact slider and the disk. The AE transducers were directly mounted onto both the arm with the slider and the disk in order to measure the slider/disk contact behavior. The AE transducer output from the disk was transmitted by the slip ring and the brush. The predicted wear of the slider and the disk based on the AE signals were computed from the relationship mentioned above. The measured wear of the slider and the disk were obtained by atomic force microscopy (AFM) and an optical surface analyzer (OSA) respectively. According to the experimental results, the predicted wear of both the slider and the disk using AE signals agreed with the wear which was measured. Therefore, wear can be estimated and monitored indirectly in-situ using the AE signals without direct measurements of the wear volume.
Modeling Cold-Rolling Processes of Commercial Twin Roll Cast Aluminum Alloys
Authors: Puchi-Cabrera E. S.
Published: July 2002

Primary rolling operations of twin-roll cast commercial aluminum alloys can be designed more efficiently on the basis of maintaining a constant rolling load throughout the rolling program. The computation of the final thickness of the strip for every pass can be conducted by means of the simplified theory of Bland and Ford, assuming a constant rolling load during the rolling schedule. Particularly, for twin-roll cast Al-1 percent Mn alloy (TRC 3003) it is possible to reduce one rolling pass if the rolling load is kept constant at about 800 ton. The implementation of this design procedure requires a knowledge of both the work-hardening characteristics of the material and the change in friction conditions throughout the operation. For this last purpose, von Ka´rma´n linear differential equation can be integrated following a more efficient computational procedure based on integrating factors and standard numerical integration methods. Also, the work-hardening characteristics of the material were determined from plane strain compression tests, on the basis of the evolution laws proposed by Sah et al. and Follansbee and Kocks. The rolling pass design that has been proposed could have clear advantages in terms of the productivity of the mill, quality of the rolled products and extension of the rolls life.
Practical Experience With the Discrete Green’s Function Approach to Convective Heat Transfer
Authors: Batchelder Keith A. , Eaton John K.
Published: July 2002

The heat transfer from a short uniform heat flux strip beneath a turbulent boundary layer with and without freestream turbulence was measured using a liquid crystal imaging technique. Freestream turbulence intensities were on the order of 12 percent. Data were taken at momentum thickness Reynolds numbers on the order of 1000 and 2000 for the turbulent and steady freestreams, respectively. Heat transfer enhancement due to the presence of freestream turbulence was quantified in terms of the ratio of the average St’s on the strip: turbulent freestream divided by steady freestream. Compared to the baseline case of a uniformly heated surface upstream of the strip, the heat transfer enhancement decreased by 20 percent. The temperature distribution measured on and downstream of the heated strip represented one column of a discrete Greens function that was used to predict the heat transfer for any arbitrarily specified thermal boundary condition given the same flowfield. Predictions are compared against correlations and numerical predictions as well as data from the literature. The details and practical applications of this approach to handling heat transfer with non-uniform thermal boundary conditions are presented.
Metal Recovery From the Waste Magnesia-Chromia Bricks With Arc Plasmas
Authors: Tanahashi N. , Takeuchi A. , Tanaka K.
Published: July 2002

A process has been developed to detoxify the waste magnesia-chromia bricks containing sexivalent chromium and recover valuable materials with arc plasma treatment. Especially magnesium and chromium, which are the major compounds of the waste bricks, could be separately recovered by carbothermic reduction with addition of iron. From the viewpoint of environmental protection and saving resources, such recovery processes are expected to be commercialized.
Stability of the Shanley Column Under Cyclic Loading
Authors: Corona E.
Published: July 2002

This paper presents a numerical study of the Shanley column under cyclic loading. The model includes intermediate deformation kinematics. The constitutive model is based on the Dafalias-Popov model. Results for fully reversed, symmetric load or displacement-controlled loading are presented. Under displacement-controlled loading, the model can exhibit a transient response which takes it away from its initial configuration, but the response eventually reaches a stable cycle. Under load-controlled loading, the model can either reach a limit cycle or develop a limit load instability that causes collapse. The responses that result in collapse are imperfection sensitive. In addition, the response of the model is also sensitive to the amplitude of the applied loading cycles.
Smooth Asymmetric Two-Dimensional Indentation of a Finite Elastic Beam
Authors: Zhou M. , Schonberg W. P.
Published: July 2002

Standard methods of beam indentation analysis use a beam theory solution to obtain the load-displacement relationship and a Hertz solution to calculate local stresses. However, when the contact length exceeds the thickness of the beam point contact can no longer be assumed and Hertzian relations are no longer valid. This paper presents an improved superposition solution technique that uses a true elasticity solution to obtain the load-displacement relationship in non-Hertzian indentation problems.
Investigation of the Effects of Completion Geometry on Single-Phase Liquid Flow Behavior in Horizontal Wells
Authors: Jiang Weipeng , Sarica Cem , Ozkan Erdal , Kelkar Mohan
Published: July 2002

The fluids in horizontal wells can exhibit complicated flow behaviors, in part due to interaction between the main flow and the influxes along the wellbore, and due to completion geometries. An existing small-scale test facility at Tulsa University Fluid Flow Projects (TUFFP) was used to simulate the flow in a horizontal well completed with either circular perforations or slotted liners. Single phase liquid flow experiments were conducted with Reynolds numbers ranging approximately from 5000 to 65,000 and influx to main flow rate ratios ranging from 1/50 to 1/1000. For both the perforation and slot cases, three different completion densities and three different completion phasings are considered. Based on the experimental data, new friction factor correlations for horizontal well with multiple perforation completion or multiple slots completion were developed using the principles of conservation of mass and momentum.
Reducing Bottlenecks in the CAD-to-Mesh-to-Solution Cycle Time to Allow CFD to Participate in Design
Authors: Dawes W. N. , Dhanasekaran P. C. , Demargne A. A. J. , Kellar W. P. , Savill A. M.
Published: July 2002

As CFD has matured to the point that it is capable of reliable and accurate flow simulation, attention is now firmly fixed on how best to deploy that CFD as part of a process to improve actual products. This “process” consists of capturing and controlling the geometry of a suitable portion of an aeroengine (e.g., a blade row, or an internal cooling system or a fan-plus-nacelle), building a mesh system, solving the flow and responding to an appropriately visualized flow field by changing or accepting the geometry. This paper looks at that process from the point of view of identifying any bottlenecks and argues that current research should be directed at the CAD-to-mesh-to-solution cycle time rather than, as has been traditional, just looking at the solver itself and in isolation. Work aimed at eliminating some of these bottlenecks is described, with a number of practical examples.
Approximate Velocities in Mixed Exact-Approximate Position Synthesis of Planar Mechanisms
Authors: Holte Jennifer E. , Chase Thomas R. , Erdman Arthur G.
Published: July 2002

A new approach to the synthesis of planar linkage mechanisms with approximate velocity constraints is proposed. The paper presents the first closed-form complex-number dyad solution to the ground pivot specification problem for two precision positions with velocity specified at one of the positions. The solution is then manipulated in order to add approximate velocity constraints to design methods for two exact positions and an unlimited number of approximate positions. The approximate position and velocity constraints facilitate more realistic representation of design objectives. Solution spaces are presented using two-dimensional ground-pivot maps. Computer implementation of the proposed methodologies would allow designers with little or no knowledge of the synthesis techniques to interactively explore maps of solutions for four-bar motion generation.
A Complex Potential-Variational Method for Stress Analysis of Unsymmetric Laminates With an Elliptical Cutout
Authors: Madenci E. , Barut A. , Nemeth M. P.
Published: July 2002

A combined complex potential-variational solution method is developed for the analysis of unsymmetrically laminated plates with finite planform geometry, subjected to arbitrary edge loads, and with an inclined elliptical cutout. This method uses complex potentials and their Laurent series expansions to reduce the potential energy of a plate to a contour integral that is evaluated numerically by the trapezoidal rule. A variational statement of equilibrium is applied to the potential energy to obtain a linear system of equations in terms of the unknown coefficients of the Laurent series, whose solutions yield the stress and displacement fields for a given problem. This approach represents a computationally efficient alternative to boundary collocation procedures that are typically used to solve problems based on complex potential theory. Comparisons are made with corresponding results obtained from finite element analysis for a square unsymmetrically laminated plate with a central inclined elliptical cutout and subjected to biaxial tension. The results confirm the validity of the solution method.
Application of H∞ Control to Improve the Current and Speed Loops of Switched Reluctance Motor Drives
Authors: Tsai Mi-Ching
Published: July 2002

In this paper the H∞ robust control technique is applied to design a switched reluctance motor drive where the rotor position sensor provides just six pulses per revolution. A control system analyzer is used to obtain the frequency responses at each design step. To reduce the effect of the inherent phase inductance variations, an H∞ two-degree-of-freedom control scheme is designed in the current-loop of the drive to achieve the demanding time-response specifications. In order to have a good load torque disturbance rejection ability, the H∞ loop shaping procedure is employed to construct a lead-lag type controller in the speed-loop of the drive. The designed H∞ controllers are evaluated in real-time experiments with a digital signal processor (DSP). The results demonstrate the effectiveness of the proposed strategy in comparison with that of a conventional design.
A Microstructural Finite Element Simulation of Mechanically Induced Bone Formation
Authors: Koontz John T. , Charras Guillaume T. , Guldberg Robert E.
Published: July 2002

A finite element method to simulate the formation of an interconnected trabecular bone microstructure oriented with respect to applied in vivo mechanical forces is introduced and quantitatively compared to experimental data from a hydraulic bone chamber implant model. Randomly located 45 μm mineralized nodules were used as the initial condition for the model simulations to represent an early stage of intramembranous bone formation. Boundary conditions were applied consistent with the mechanical environment provided by the in vivo bone chamber model. A two-dimensional repair simulation algorithm that incorporated strain energy density (SED), SED gradient, principal strain, or principal strain gradient as the local objective criterion was utilized to simulate the formation of an oriented trabecular bone microstructure. The simulation solutions were convergent, unique, and relatively insensitive to the assumed initial distribution of mineralized nodules. Model predictions of trabecular bone morphology and anisotropy were quantitatively compared to experimental results. All simulations produced structures that qualitatively resembled oriented trabecular bone. However, only simulations utilizing a gradient objective criterion yielded results quantitatively similar to in vivo observations. This simulation approach coupled with an experimental model that delivers controlled in vivo mechanical stimuli can be utilized to study the relationship between physical factors and microstructural adaptation during bone repair.
Extrusion Through Spherical Dies—An Upper Bound Analysis
Authors: Gordon W. A. , Van Tyne C. J. , Sriram S.
Published: July 2002

An upper bound solution for extrusion through a spherical die has been developed. Equations for the velocity and strain rate fields in the deformation zone are presented. The equations to determine the internal power of deformation, shear power losses along the two surfaces of velocity discontinuity and friction power losses along the die workpiece interface are shown. In order to maintain generality, these power terms have been calculated via numerical integration methods. The shear power losses and the friction power losses for the extrusion through a spherical die are of similar magnitude as for the extrusion through an “equivalent” conical die. The internal power of deformation is greater for the spherical die as compared to the conical die especially at large radius of curvatures for the spherical die. From the model the optimal die curvature can be determined which minimizes the pressure required to extrude through a spherical die. The analysis presented herein can be generalized to any axisymmetric die shape, which produces a cylindrical product from a cylindrical billet. This extension can be accomplished with minimal changes in the model.
Behavior of the Two-Phase Mushy Zone During Freeze Coating on a Continuous Moving Plate
Authors: Tangthieng C. , Cheung F. B. , Shiah S. W.
Published: July 2002

The process of freeze coating of a binary substance on a chilled moving plate is studied theoretically with special emphasis on the behavior of the two-phase mushy zone. The flow and heat transfer in five separate regions of the system, i.e., the moving plate, the freeze coat, the two-phase packing region, the two-phase dispersed region and the molten substance region, are formulated mathematically to describe the freeze-coating process. A supplemental equation derived from a simplified phase diagram and an appropriate viscosity model are employed to complete the mathematical description of the two-phase mushy zone. The system of equations is solved by a combined analytical-numerical technique to determine the spatial variations of the solidus and liquidus fronts. Effects of seven controlling parameters, including the freeze coat-to-wall thermal ratio, the wall subcooling parameter, the molten substance superheating parameter, the Prandtl number, the Stefan number, the equilibrium partition ratio, and the packing limit fraction, on the behavior of the two-phase mushy zone and the freeze-coating process are determined.
Behavior of Localized Bottom Bulge in Aboveground Oil Storage Tanks Under Liquid Pressure
Authors: Yoshida Shoichi
Published: July 2002

The bottom plate of aboveground oil storage tanks can bulge, separating from the foundation due to welding deformation. When such a bulge is subjected to liquid pressure, it deforms continuously to make contact with the foundation from the edge, and the remaining area of the bulge decreases with increasing liquid pressure. As a result, the deformation is extremely localized and plastic strain occurs at the bulge. This paper presents a plane strain finite element analysis for the evaluation of localized bottom bulges in aboveground oil storage tanks. Load-incremental, elastic-plastic large deformation analysis is carried out considering the bottom plate contact with the foundation. The relationship of the plastic strain at the bulged bottom plate to the liquid pressure is discussed together with the deformation of the bulge. As a result, the bottom plate thickness has a significant effect on the deformation, but the bulged height does not. After the bulged center makes contact with the foundation, the stress and strain do not increase with increasing liquid pressure. In addition, the permissible bulged profile specified by API Standard 653 elastically deforms to make contact with the foundation under low liquid pressure.
In-Plane Wave Propagation Through Elastic Solids With a Periodic Array of Rectangular Defects
Authors: Scarpetta E. , Sumbatyan M. A.
Published: July 2002

In the context of wave propagation in damaged (elastic) solids, an analytical approach is developed to study normal penetration of a longitudinal plane wave into a periodic array of rectangular defects. Reducing the problem to some integral equations holding over the base and height of the openings, a direct numerical method is applied to give a complete solution for various exact or approximated forms. Several figures show the peculiarities of the structure and lead to physical conclusions.
Data Interface Software for Windows PC-compatible Virtual Reality Scene Graphs
Authors: Banerjee Pat
Published: July 2002

In this article we review commonly used data translation software for Windows PC-based virtual reality (VR) scene graphs. The goal is efficient data input and output from various VR software. VR using Windows OS is considered because it is growing, and is likely to become significant in the years to come. Also many of Windows solutions currently operate on LINUX or UNIX, so it represents interoperability to some extent. This article does not deal with the user tracking software in VR, it however deals with software capabilities for the scene graph content creation from a rendering, navigation and animation standpoint. Among others, in particular we review Pro/Engineer-VR software interface, because such an interface is highly representative of the challenges and difficulties involved. Data conversion represents a significant challenge, e.g. according to a National Institute of Standards and Technology (NIST) study, imperfect interoperability is costing the US automotive supply chain at least one billion dollars per year [1].
Control and Identification of Vortex Wakes1
Authors: Anderson C. R. , Chen Y.-C. , Gibson J. S.
Published: July 2002

In this paper, control and identification methods for vortex wakes are investigated. The particular problem studied concerns the stabilization of vortices behind a flat plate, using backside suction as an actuator. The flow dynamics are modeled with a discrete vortex method. Feedback control results for a linear PI controller are presented as well as identification results for a class of input/output models that can be used to design more sophisticated controllers. [S0022-0434(00)00502-5]
Erratum: “Effect of Temperature and Strain Rate on Mechanical Properties of 63Sn/37Pb Solder Alloy” [ASME J. Electron. Packag., 121, pp. 179–185]
Authors: Shi, X. Q. , Zhou, W. , Pang, and H. L. J. , Wang Z. P.
Published: July 2002

[S1043-7398(00)01601-7]
On the Sensitivity of the Asperity Pressures and Temperatures to the Fluid Pressure Distribution in Mixed-Film Lubrication
Authors: Chang L. , Zhao Yongwu
Published: July 2002

This paper studies the sensitivities of the asperity pressures and temperatures to the fluid pressure distribution in concentrated contacts operating in the regime of mixed-film lubrication. Two fluid pressure distributions are used in the study. One is a Hertz-like distribution that neglects micro-EHL responses of the lubricant, and the other models the micro-EHL effects with significant pressure rippling. The asperity pressures and temperatures are deterministically calculated in time by numerically solving the asperity-contact and the transient energy equations as the two surfaces move relative to each other. The contact is simulated for sufficient time duration until the samples of the calculated asperity variables reach a statistical equilibrium that reflects the random-process nature of the problem. Parametric analyses are carried out that cover a wide range of operating conditions of practical interest. The results obtained consistently suggest that the asperity pressures and temperatures are not sensitively related to the fluid pressure. This insensitivity supports the use of any fluid pressure distribution consistent with the underlying mixed-film problem, rather than determining it by numerically solving the Reynolds equation at every time step of the simulation process. The study lays a foundation on which to advance modeling of the mixed-film contacts with a proper balance among model robustness, computational efficiency and solution accuracy. [S0742-4787(00)01101-2]
Modeling of the Non-Linear Rheological Behavior of a Lubricating Grease at Low-Shear Rates
Authors: Madiedo Jose´ M. , Franco Jose´ M. , Valencia Concepcio´n , Gallegos Crı´spulo
Published: July 2002

This paper deals with modeling the non-linear rheological behavior of lubricating greases at very low shear rates. With this aim, dynamic linear viscoelastic, non-linear stress relaxation, transient and steady-state shear flow, and transient first normal stress difference measurements have been carried out on a diurea-derivative lubricating grease. A factorable non-linear viscoelasticity model, the Wagner integral model, derived from the K-BKZ constitutive equation, was used in order to predict the non-linear rheological response of the above-mentioned lubricating grease under shear. The time-dependent part of the model was described by its linear relaxation spectrum, whilst two different damping functions (Wagner and Soskey-Winter’s damping functions) were analysed as the strain-dependent factor. The continuous linear relaxation spectrum was estimated, using regularization techniques, from the dynamic linear viscoelasticity functions. The damping function was calculated from non-linear stress relaxation tests. The constitutive model, with Soskey-Winter’s damping function, predicted the steady-state flow curve, the transient shear stress and the transient first normal stress differences of the lubricating grease studied fairly well. [S0742-4787(00)01603-9]
A Short History of High Pressure Technology From Bridgman to Division 3
Authors: Kendall David P.
Published: July 2002

This paper will briefly review the development of high pressure technology from the early basic science through the major applications that have driven the technology. These include gun barrel development, the polyethylene process, and isostatic pressing and crystal growth. A parallel effort on the development of man-made diamonds will be mentioned. More recently, jet cutting and food sterilization are driving the technology in new directions. The paper will discuss the differences in design approach between thin-walled and thick-walled cylinders, including the use of favorable residual stresses. The author’s experiences with the development of the autofrettage process for gun barrels, including the “swage” method, will be reviewed. The history of the development of the new Division 3 of Section VIII of the Boiler and Pressure Vessel Code will be described, including some of the controversies and compromises that arose during the process. [S0094-9930(00)01403-7]
Risk-Based Hazardous Release Protection and Prevention by Inspection and Maintenance
Authors: Brown Samuel J. , Le May Iain
Published: July 2002

In-service inspection and maintenance assessment of plant and equipment to reduce the risk of failure and hazardous release have been used for many decades as cost-effective procedures in concert with design, material selection, defect criteria, fabrication, and operation/use. Codes and standards have, more recently, sought to provide hazardous release protection as an additional means of reducing risk by means of criteria based on risk (event probability and consequences), including maintenance and inspection. These criteria use risk-based methods for prioritizing inspection and maintenance. In a power station or refinery, for example, the risk of unplanned shut-down is related to the failure or malfunction of a relatively small number of items. Risk-based maintenance and inspection allows efforts to be concentrated on items involving the highest risk, with a proportionate reduction in effort for low-risk items. Hence, base-load operating times can generally be increased, while maintaining the same or reduced level of risk. Maintenance and inspection play a vital role to reduce risk by more accurately quantifying event probability. Where there is a possibility of high-risk catastrophic failure, the consequences and risk to personnel, environment and equipment can be rendered tolerable to negligible if appropriate protective systems are in place with reduced maintenance and inspection. This paper reviews several cases in which the authors have been involved and in which failures would have been prevented if proper risk assessment procedures had been in place or in which assessment of risk was made to prevent failure. [S0094-9930(00)02203-4]
Poly (iso-butyl methacrylate) by XPS
Authors: Moulder J. F. , Stickle W. F. , Sobol P. E.
Published: July 2002

XPS measurements are presented for high purity poly (iso-butyl methacrylate). The data include the valence band region and the principal core levels.
SrCl2 by XPS
Authors: Vasquez Richard P.
Published: July 2002

X-ray photoemission measurements for high purity, ultradry SrCl2 which has not been exposed to the atmosphere are presented. The data include measurements of the valence band region and energy losses from the prinicipal core levels.
CuBr2 by XPS
Authors: Vasquez Richard P.
Published: July 2002

X-ray photoemission measurements of CuBr2 are presented. XPS studies of Cu compounds in this laboratory have been motivated by the need to identify species on chemically etched high temperature superconductor surfaces [see R. P. Vasquez, M. C. Foote, and B. D. Hunt, J. Appl. Phys. 66, 4866 (1989)].
Oxygen-free 6061 Aluminum Alloy Surface Produced in Ammonia Glow Discharge: An AES Spectrum
Authors: Wang Paul W. , Sui Shixian , Zhang Lipeng , Durrer William G.
Published: July 2002

An oxygen-free 6061 aluminum surface was obtained for the first time in our knowledge in an ultrahigh vacuum (UHV) environment after ex situ ammonia dc plasma treatment. The specimen was first processed in an ammonia plasma chamber for 5 to 6 h then taken from the treatment chamber, mounted on a sample holder in air, and inserted into an UHV system through a sample transfer chamber. The sample was cleaned by 2.8 keV Ar+ ion bombardment for about 10 min to remove the oxide layer that had formed in air. A clean metallic aluminum Auger spectrum with no detectable oxygen peak was obtained under standard operating conditions with a Perkin-Elmer Physical Electronics 560 spectrometer. The kinetic energy of the Auger electrons was calibrated using sputter-cleaned Cu surfaces. The oxygen free Al surface is a key to thin film growth/deposition on aluminum or aluminum alloy surfaces.
UHV-Cleaved Single Crystal MgO(100) by Electron Energy Loss Spectroscopy
Authors: Kurtz Richard L. , Henrich V. E.
Published: July 2002

Interband electron energy loss (EELS) spectra probe the joint density-of-states between the initial and final electron states. In the wide scan spectrum, the structure between 0 and about 50 eV loss energy corresponds to transitions originating in the O 2p valence band. Between 50 and 80 eV, the initial state is the Mg 2p core level, and above about 90 eV the initial state is the Mg 2s. EELS is also very sensitive to small concentrations of defects on the MgO surface. The narrow scan spectrum of the clean, cleaved surface exhibits a surface-defect loss feature in the 1–2 eV region which is sometimes present on UHV-cleaved (or ion-bombarded) surfaces; that feature is not present on the cleaved surface used for the wide scan. After exposure to O2, the defect loss feature has essentially disappeared, with only minor changes in the rest of the spectrum. [See V. E. Henrich and R. L. Kurtz, J. Vac. Sci. Technol. 18, 416 (1981), for a discussion of the nature of the surface defects.]
Core-level Binding Energies and Photoelectron Diffraction in Cleaved and Homoepitaxial MgO(100)
Authors: Chambers S. A. , Tran T. T.
Published: July 2002

Absolute binding energies of selected core levels and x-ray excited Auger transitions are reported for MgO(001) cleaved in air, and for homoepitaxial MgO grown at 750 °C. In addition, polar photoelectron diffraction scans of Mg KL2,3L2,3 and O 1s intensities measured at high angular resolution are reported. The influence of Auger and photoelectron diffraction on angle-resolved XPS of rocksalt crystals of this type is discussed.
Gibbsite (α-Al(OH)3) by XPS
Authors: Rotole John A. , Sherwood Peter M. A.
Published: July 2002

The XPS spectra of Gibbsite were collected with a VSW HA150 using monochromatic Al Kα x-radiation. Monochromatic radiation provides a distinct clarity to the peak structure in the valence band of Gibbsite due to the absence of interfering x-ray satellites from the intense O 2s region. Variations in the intensities and peak separation of the two-peak structure in the valence bands of the oxides, hydroxides, and oxyhydroxides of aluminum allow one to distinguish between these compounds. The valence band, survey, and the Al 2s, Al 2p, O 1s, and C 1s core levels are reported.
Electronic Structure of Ag/Pt(111) Studied by UPS
Authors: Tsay Jyh-Shen , Shern Ching-Song
Published: July 2002

When Ag overlayers are deposited on a Pt(111) surface, a characteristic peak of Ag 4d appears. Due to the spin-orbit interaction, subsequent deposition of Ag causes the main peak splits into 4d3/2 and 4d5/2 peaks. This is indicative of the transformation from the atomic state to the solid state. The spectra become broader after the films were annealed at 600 K.
Thermal Desorption of Ultrathin Ag Film, from a Pt(111) Surface, by AES
Authors: Tsay Jyh-Shen , Yao Yeong-Der , Shern Ching-Song
Published: July 2002

In the state of thermal equilibrium, the desorption of ultrathin Ag films from a Pt(111) surface is demonstrated to occur above 700 K and to be complete above 1000 K by Auger electron spectroscopy. The corresponding spectra are presented. The specimens were ultrathin Ag/Pt(111) films grown at 360 K with Ag coverage of 0.5, 1.0, and 1.5 of monolayers. The Pt(111) surface was cleaned by cycles of ion sputtering and annealing in an ultrahigh vacuum chamber. All spectra were collected with a surface science instrument of VG Microtech.
Analysis of a 30% Glass-filled Poly(propylene) Polymer by XPS
Authors: Lannon John M. , Meng Qingru
Published: July 2002

We report x-ray photoemission spectra for a 30% glass-filled poly(propylene) (PP) polymer. XPS spectra were acquired with a SSI model SSX-100 instrument, using monochromated Al Kα x-rays. We present the survey spectrum (binding energy 0–1000 eV) and a narrow spectrum of the C 1s and O 1s photoelectron peaks.
Analysis of a 13% Glass-filled Nylon 6,6 Polymer by XPS
Authors: Lannon John M. , Meng Qingru
Published: July 2002

We report x-ray photoemission spectra for a 13% glass-filled nylon 6,6 polymer (PA66). XPS spectra were acquired with a SSI model SSX-100 instrument using monochromated Al Kα x-rays. We present the survey spectrum (binding energy 0–1000 eV) and a narrow spectrum of the C 1s, O 1s, and N 1s photoelectron peaks.
Ethylene-vinyl Alcohol Copolymer (EvOH) by XPS
Authors: Militello Maria C. , Gaarenstroom Stephen W.
Published: July 2002

XPS spectra of ethylene-vinyl alcohol copolymer (EvOH) are presented. The spectra were collected using monochromated Al Kα x-rays. Spectra include a survey scan and the C 1s and O 1s regions.
Adsorption of Anhydrous Hydrogen Fluoride onto Silicon and Native Oxide by XPS
Authors: Saito Yoji
Published: July 2002

Adsorption of anhydrous hydrogen fluoride (AHF) on surfaces of (100) oriented single-crystalline silicon and the native oxide was investigated by in situ x-ray photoelectron spectroscopy (XPS) at room temperature. A significant component at 687.0 eV binding energy in the observed XPS spectra of the F 1s core level is estimated to be derived from adsorbed HF molecules.
In situ XPS Spectra of Nonstoichiometric Fe3−δO4(100) Films
Authors: Fujii Tatsuo , Voogt Frans C. , Hibma Tjipke , Sawatzky George A.
Published: July 2002

XPS core- and valence-level spectra of various nonstoichiometric Fe3−δO4 films were measured systematically as a function of the δ value. The films were prepared epitaxially on MgO(100) substrates by NO2-assisted molecular beam epitaxy and characterized in situ with RHEED, LEED, and XPS. Stoichiometry of the films was controlled precisely by adjusting the NO2 pressure during deposition and analyzed ex situ by conversion electron Mössbauer spectroscopy.
Effects of plasma excitation power, sample bias, and duty cycle on the structure and surface properties of amorphous carbon thin films fabricated on AISI440 steel by plasma immersion ion implantation
Authors: Zeng Z. M. , Tian X. B. , Kwok T. K. , Tang B. Y. , Fung M. K. , Chu P. K.
Published: July 2002

Plasma immersion ion implantation is a nonline-of-sight method for fabricating amorphous carbon or diamond-like-carbon coatings on steels to improve the surface properties. In this work, carbon thin films are synthesized on 9Crl8 (AISI440) stainless bearing steel by acetylene (C2H2) plasma immersion ion implantation (PIII). The effects of the processing parameters, including rf power, sample voltage pulse duty cycle, and target bias, on the structure and surface properties of the carbon thin films is systematically investigated employing Raman spectroscopy, Auger electron spectroscopy, friction coefficient measurement, and wear test. The results reveal that carbon films several hundred nanometers thick with a well-mixed interface are formed on the 9Crl8 steel after C2H2 PIII, but the structure and properties of the carbon films vary greatly under different PIII conditions. There is an optimal process window within which the synthesized films have superior properties, and current densities that are too high do not yield films with the desired performance.
Low-temperature magnetron sputter-deposition, hardness, and electrical resistivity of amorphous and crystalline alumina thin films
Authors: Li Quan , Yu Yuan-Hsin , Singh Bhatia C. , Marks L. D. , Lee S. C. , Chung Y. W.
Published: July 2002

Aluminum oxide films were grown by reactive magnetron sputtering. In order to maintain a stable deposition process and high deposition rate, a pulsed direct current bias was applied to the aluminum target and the substrate. An external solenoid was used to form a magnetic trap between the target and the substrate. The influence of substrate temperature, substrate bias, and the magnetic trap on film growth and properties was studied by different surface and thin-film analysis techniques and electrical measurements. Normally, amorphous alumina films were produced. However, under optimum process conditions, crystalline alumina films can be obtained at temperatures as low as 250 °C, with a hardness ∼20 GPa and excellent electrical insulating properties.
Chemical structure change of thin films prepared from nonpolymeric organic compounds by pulsed laser deposition
Authors: Kajitani Takahiro , Tanaka Osamu , Tange Yoshihiro , Matsuda Hideaki , Ooie Toshihiko , Yano Tetsuo , Yoneda Masafumi , Katsumura Munehide , Suzaki Yoshifumi
Published: July 2002

Thin films from six kinds of nonlinear optical nonpolymeric organic compounds were prepared by pulsed laser deposition (PLD) using a KrF excimer laser (248 nm) at various fluences up to 50 mJ/cm2. Changes in the chemical structure of the films with changes in fluence were studied. The experimental results show that for every compound at least minor decomposition has already started at the threshold fluence for deposition. More serious degradation occurs with increasing fluences, and little of the original chemical structure remains in films prepared by PLD at a fluence of 50 mJ/cm2.
Study of forming a p+ poly-Si gate by inductively coupled nitrogen plasma nitridation of the stacked poly-Si layers
Authors: Juang M. H.
Published: July 2002

Formation of a p+ poly-Si gate by using the stacked poly-Si layers that are nitridized by using inductively coupled nitrogen plasma (ICNP) has been studied. The stacked poly-Si gate structure consists of three poly-Si layers with thickness of 50, 50, and 100 nm, respectively. As for the control samples that do not receive nitrogen plasma nitridation, when they are annealed at 900 °C, the gate oxide integrity is significantly degraded and the flat-band voltage (Vfb) shift is large, attributable to considerable boron penetration through gate oxide. If the ICNP treatment is directly done with respect to the gate oxide layer, the Vfb shift can be considerably reduced, but the resultant gate oxide integrity is even much worse than that for the control samples. However, for the specimens that sustain ICNP treatment immediately after the deposition of the first poly-Si layer, the degradation of gate oxide integrity and the Vfb shift are significantly alleviated even at 900 °C. Hence, the process scheme that employs the stacked poly-Si gate nitridized by the ICNP treatment is highly available for forming a p+ poly-Si gate.
Electrodepositing a hard copper film from a pyrophosphate bath
Authors: Chen Y. T. , DePew J. R. , McCabe H. D.
Published: July 2002

A copper film with hardness greater than 200 Kn50 was electrodeposited on aluminum substrates pretreated with a tin–bronze process. Electron microscopy revealed that the tin–bronze process left a very thin film of tin on the aluminum surface. The as-plated pyrocopper showed an average grain size of 300 Å with scattered large grains embedded in the matrix. The early stage of the copper growth was investigated carefully. The effect of brightener and other additives on the structure and properties of the copper film was also investigated. The addition of gold enhanced a (110) preferred orientation, and a brightener tended to induce a (100) preferred orientation. Samples were heat treated at 400, 600, 800, and 1000 °C. The effect of heat treatment on the microstructure and hardness was studied by transmission electron miscroscopy. Heat treatment caused grain growth and recrystallization. Many twin bands were observed at 400 and 600 °C. Surface facets were observed after annealing at 800 and 1000 °C. The hardness of the copper decreased with increased heat treatment.
Formation and Growth of Thin Epitaxial Films (Homoepitaxy of Semiconductors)
Authors: Alexandrov L. N. , Sidorov Yu. G.
Published: July 2002

Epitaxial growth of semiconductors in real crystal substrates begins by two- and three-dimensional nucleation. It is necessary to take into account the nucleus–substrate boundary energy and substrate surface defects, as well as the misfit angle of nucleus and substrate lattices. For the homoepitaxial growth the calculation of two- and three-dimensional nucleation rate on the surface (111), (110), (111) for different supersaturations for quasispherical nuclei is made. It is shown that for GaAs in gas transport processes the formation of films on singular facets is realized by the three-dimensional nucleation. Deviation of substrate orientation from that for the singular planes increases the contribution of the mechanisms of two-dimensional nucleation and of growth by step propagation.